3 545 398a

O & M Manual Generator Control Panel

PE / VIE_AOE (AYYILDIZ) Dwg.No.: 3 545 398 Rev.A

Edition: 0.00.0000 Document2 /78

Excitation SystemforGenerator Control Panel

Operation andMaintenance Manual




CAUTION

Installing, commissioning and operating of this product may be performed by thoroughly trainedand

specialized personnel *

only. We explicitly will not take any responsibility for any damage on our products caused by im-proper installation, configuration and handling. Internal modifications must solely be carried out byspecialized personnel authorized by VA TECH SAT GmbH & Co / Department PE.

* Definition: Specialized personnel, when authorized and properly instructed, may perform fol-lowing tasks.

• Installing, mounting, commissioning and operating of the apparatus and the system when fa-miliar with,

• Switching operations according to the relevant Safety Standards for medium and high voltageswitchgear, i.e. plant energizing and de-energizing, preventive isolation, safety earthing and se-curing, when instructed,

• Maintenance and application of safety gear according to Standard Rules and Regulations,• First Aid after extensive training.

CAUTION

Insulation resistance- and high voltage tests must never be applied and may only be carried out onthe power circuits. Improper use of such tests could damage the system's solid state components.




TABLE OF CONTENTS1. INTRODUCTION 7

2. PRODUCT DECLARATION AND CE-IDENTIFICATION 7

3. BASIC PRINCIPLE OF EXCITATION SYSTEMS 8

4. BASICS OF THE THYNE4 SYSTEM 9

5. SUBSTANTIAL FEATURES 10

6. EXCITATION SYSTEM THYNE4 SPECIFICATION 11

6.1. POWER SUPPLY 116.1.1. With Excitation Transformer in Generator Shunt Field Connection 116.1.2. External- and Test Supply from the Station Auxiliary System 12

6.2. POWER CIRCUIT DESIGN 136.2.1. Rectifier Unit and Overvoltage Protection 136.2.2. De-excitation Equipment and DC Overvoltage Limiter 136.2.3. Field Flashing 136.2.4. Current Boosting 14

6.3. AUTOMATIC VOLTAGE REGULATOR AND GATE CONTROL GMR3 146.3.1. Overview 146.3.2. Description of Hardware 166.3.3. Description of Software 20

6.4. AUTOMATIC VOLTAGE REGULATOR 296.4.1. Voltage Regulator (Automatic Mode) 296.4.2. Field Current Regulator (Manual Mode) 306.4.3. Automatic Follow-Up Change Over between Voltage Regulator and

Field Current Regulator 306.4.4. Operation, Indication and Digital Sequencer 316.4.5. Software package WINOPER 31

7. INTERFACE OF EXCITATION SYSTEM 32

7.1. EXCITATION POWER CIRCUIT 327.1.1. Excitation Supply (to exciter) 327.1.2. Excitation AC Supply and Excitation Test Supply 327.1.3. Field Flashing and Current Boosting 327.1.4. CT / PT and Actual Measured Value Connections 32

8. LOCAL OPERATION 33

8.1. Introduction 33

8.2. Description of Functions 348.2.1. Basic Screen - Main Menu 348.2.2. Alarms, Trips 368.2.3. Actual Values 368.2.4. Regulator Settings 378.2.5. Maintenance 388.2.6. Terminal Mode 38

8.3. Operating Instructions 408.3.1. Preconditions 408.3.2. Keyboard Functions 40




8.3.3. Password - Write Protection 428.3.4. Parameter Modifications 43

8.4. Error Processing 448.4.1. Error Processing for MRB Board and IO Hardware 448.4.2. Operating and Terminal Errors 45

9. REMOTE CONTROL 47

9.1. INTERFACE 479.1.1. Digital Inputs 479.1.2. Digital Outputs 48

9.2. OPERATING MODES 489.2.1. Voltage Regulator (Automatic Mode) 489.2.2. Field Current Regulator (Manual Control) 499.2.3. Power factor / Reactive Power Regulation 499.2.4. Change Over Between the Automatic and Manual and Power factor /

Reactive Power Regulation Mode 50

9.3. DE-EXCITATION 51

10. MAINTENANCE AND TROUBLE SHOOTING 52

10.1. ALARM ANNUNCIATION 5210.1.1. General and Accepting/resetting 5210.1.2. List of Possible Alarm Annunciation 5310.1.3. Detailed Specification 53

10.2. FAULTFINDING 59

10.3. FAULTY PRINTED CIRCUIT CARDS 63

10.4. PERIODIC MAINTENANCE 64

11. INSTALLATION 64

12. PRE-SETTINGS FOR COMMISSIONING 65

12.1. SWITCHES ON MRB3 MODULE 65

12.2. LIST OF THE CONFIGURATION PARAMETERS 65

12.3. CALIBRATION OF LC-DISPLAY 65

13. COMMISSIONING 68

13.1. PREPARATION FOR COMMISSIONING 68

13.2. MEASURING POINTS 68

13.3. CONSIDERATIONS 6913.3.1. Calibration Principle 6913.3.2. Principle for Optimizing the Regulator 7113.3.3. Recommended Settings 72

13.4. CARRYING OUT COMMISSIONING 7213.4.1. Tests at Standstill 7313.4.2. Short Circuit Tests – If Applicable 7313.4.3. Open Circuit Voltage Tests 7313.4.4. On Load Tests 7413.4.5. Remaining Activities 75




14. TECHNICAL DATA 76

14.1. CHARACTERISTICS 7614.1.1. Dimensions 7614.1.2. Excitation maximum capability 7614.1.3. Rectifier capability 7614.1.4. Field breaker capability 76

14.2. EMC COMPATIBILITY 76

15. PLEASE NOTE! 77




LEGEND AND ABBREVIATIONS

S Apparent powerP Active powerQ Reactive powerV, U VoltageI CurrentUG Generator voltageIG Generator currentIw Generator active currentIb Generator reactive currentIF Field currentfg Generator frequency3ph Three phaseDC Direct currentC CommandA AnnunciationB Command (Befehl) refers to digital signalsNB No command refers to digital signalsM Annunciation (Meldung) refers to digital signalsNM No annunciation refers to digital signals

Note: Index “n”, “N” means nominal, e.g. UGN is generator nominal voltage.




1. INTRODUCTION

The THYNE4 is an excitation system comprising the complete power circuit part as well as thedigital regulating and control functions. This operating manual shall assist to be able to use allfeatures contained in the system and also supply the necessary information required for mounting,installing, commissioning and maintenance.

However, should there be any questions at all regarding this excitation system please contact ourHead Office in Vienna.

2. PRODUCT DECLARATION AND CE-IDENTIFICATION

The excitation system THYNE4 is designed and manufactured in accordance with the CE-identification Standard (93/68/EWG) with consideration of the EU-Standards for low voltage switchgear (73/23/EWG) as well as the EU-Standard for electromagnetic compatibility (89/336/EWG).

Standards considered:

VDE 160,EN 50178

Ausrüstung von Starkstromanlagen mitelektronischen Betriebsmitteln

Electronic equipment for use in powerinstallations

IEC 60146 Halbleiter-Stromrichter Semiconductor convertors

IEC 60726 Leistungs-transformatoren Dry-type power transformers

IEEE 421 B High Potential Test Requirements forExcitation Systems for SynchronousMachines

IEC 61000-4 Elektromagnetische Verträglichkeit Electromagnetic Compatibility




3. BASIC PRINCIPLE OF EXCITATION SYSTEMS

For the operation of a synchronous generator a magnetic rotor field is required which a DC currentflowing in the rotor windings produces. This DC current is generated by the excitation system.

There are several kinds of excitation systems which are employing either rotating machinery orstatic elements. A static excitation system is connected via an excitation transformer to a powersource. Should the source be the generator winding itself we are referring to a shunt field excita-tion system. When the excitation transformer is connected to an external power source, e.g. an ACgenerator on the rotor shaft or to the auxiliary supply of the plant, it is denominated as excitationsystem with an external supply. The voltage output of the excitation transformer is rectified andregulated and is transmitted to the field winding via the rotor brushes.

A further possibility is the use of a pilot exciter machine which can either be a brushless AC exciterwith flywheel diodes or, especially in older plants, a DC exciter machine. The pilot exciter is actingas an amplifier of the field current. The flywheel diodes are mounted on the common shaft of thegenerator rotor and pilot exciter and are supplying the necessary DC current for the rotor. Theregulation of the pilot exciter field is performed via a voltage regulator with a fully controlled thyris-tor unit.

The excitation performs either

• Production and regulation of the generator voltage when not connected to the power grid orwhen operating as an isolated system

• Production and regulation of the reactive power when operating in parallel with other units to thepower system. Maintaining the voltage level is caused by the grid system itself provided that it isable to do so. When during on-line operation the rotor current is reduced too much then thestability of the generator set is also decreasing. This can lead to loss of synchronism with sub-sequent damage to the generator within a relatively short period due to additional currents cir-culating in the generator windings. Generator speed and active power output is solely deter-mined by the turbine drive

The figure below shows the permissible load range for stable operation of the generator set.

Max. permissible stator current

Min. Permissible rotor current

P (pu), active power

-0,5-1

Stabiliy limit

0.5

1

Q (pu), reactive power0,5 1

Max. permissible rotor current

Operating range




4. BASICS OF THE THYNE4 SYSTEM

The THYNE4 system is an integrated compact static and numeric excitation system for excitationand regulation of small and medium sized synchronous alternators having either AC or DC excitermachines. The central component is the THYNE4 device, which is containing the complete powercircuit with a single or three phase fully controlled thyristor bridge as well as the integrated micro-processor system of the GMR3 family for all control and regulating operations.

The exciter cubicle contains all power circuits (except excitation transformer), the automatic volt-age regulator and the complete sequencer, which is necessary to control the individual compo-nents. The system also comprises a local operating panel with alarm indication, which enableslocal operation and quick trouble-shooting in case of excitation failures.

The excitation system THYNE4 supports all standard excitation systems, such as generator shuntfield excitation, systems employing an excitation transformer supplied by auxiliary power and ex-citation via a permanent magnet generator PMG.

The local control and alarm annunciation facilities enable the operating staff to locally control theexcitation system, read the actual measured values and also provide swift and precise diagnosisand repair in case of component failure.

The complete THYNE4 System is consisting of:

• Fully controlled thyristor bridge• DC overvoltage limiter• AC overvoltage limiter• Field flashing• Current boosting• Voltage regulator with limiters• Additional regulators: reactive power regulator, power factor regulator• Field current regulator• Automatic follow-up and transfer between voltage regulator and field current regulator• Integrated digital sequencer for internal control sequences• Facilities for local control indication and alarm annunciation• Secondary fuses of the HV excitation transformer• Excitation matching transformer• Voltage actual value provided by a set of PT's (3 phase or single phase)• Generator current provided by a set of CT's for the cross current compensation (3 phase or 1

phase)




5. SUBSTANTIAL FEATURES

• Supply via external excitation transformer in shunt field connection• Nominal frequency range between 50 Hz and 400 Hz

Operating range from 10 Hz to 440 Hz• Integrated µP-system of the GMR3 type for digital sequencer and regulation• Voltage regulation in automatic mode with inner loop current regulating• Field current regulation in manual mode• Adjustable active and reactive load compensation• Following limiters are provided in the standard design:

− Maximum field current limiter with an instantaneous and delayed response− Overfluxing limiter (V / Hz)− Stator voltage limiter− Under excitation limiter

• Diode fault monitoring on AC exciter machines with flywheel diodes for open circuit or shortcircuit

• Soft-Start feature, i.e. start the initial raising of the generator voltage with a defined rate of risewithout hunting

• Manual and automatic smooth transfer from automatic to manual operating mode• Additional regulators: p.f. regulator or reactive power regulator selectable on the excitation unit• All set value potentiometers are part of the software having no contacts and therefore require

no maintenance.• Single phase fully controlled bridge rectifier• Field discharging of the excitation machine's field circuit• Initial excitation effective for generator shunt field excitation• Current boosting to permit the excitation ceiling characteristics during transient conditions (i.e.

short circuits) for excitation systems in shunt field connection.• Manually operated links to change over to the external test supply for the test purposes• Operation and indication unit for local operation at the device or excitation cubicle with the

corresponding feedback, i.e. excitation ON and OFF, set value RAISE and LOWER, operatingmode selection and resetting the alarm annunciation

• Above control unit comprises a keypad for the operating commands and a four line LC displayfor annunciation and measured values

• Real time sequence alarm display of an excitation failure• Display of following measured values via the LC display of the control unit:

− Generator voltage− Generator current− Field current− Generator active power− Generator reactive power− Generator power factor

• Alarm display in correct time sequence• Redundant supplies for regulator from the existing station battery and from the excitation sup-

ply.• Defined communication interface ports with voltage-free inputs and outputs for remote control

and annunciation




6. EXCITATION SYSTEM THYNE4 SPECIFICATION

The THYNE4 system is distinguished by a uniform hard- and software for two different power cir-cuit supply for the excitation system. Besides the power circuit it contains the voltage regulator, thefield current regulator, additional regulators as well as the complete sub-automatic system neces-sary for the control of the individual components.

6.1. POWER SUPPLY

6.1.1. With Excitation Transformer in Generator Shunt Field Connection

The excitation power is provided by a single-phase supply from the generator terminals in shuntfield connection via the excitation transformer or from a single-phase station auxiliary supply. Therectified field voltage from the thyristor is connected to the field circuit via the field contactor.

The internal regulating matching transformer is connected to the ac supply of the excitation systemand provides with it's first secondary output the synchronizing voltage of the regulator for thyristorcommutation. The second transformer output is producing via rectifiers the buffered 24 VDC forthe regulation system. The transformer is of dry type.

The system supports AC exciter of machine arrangement.

The field and rotor magnitudes can be operating within the following ranges: • Field voltage: positive and negative• Field current: positive• Rotor voltage and rotor current: positive




THYNE4

AC-exciter machine

Machine arrangement

Actualvaluesensing

Gen.∼

Excitation

transformer

Fig. 1: Power circuit THYNE4 with shunt field excitation

6.1.2. External- and Test Supply from the Station Auxiliary System

During first commissioning, i.e. short circuit- and open circuit tests, heat run, protection and excita-tion setting and for subsequent periodic checks an external test supply not depending on the gen-erator voltage output is necessary.

For this purpose an external supply from the auxiliary system can be taken whereby for this pur-pose the manually operated links should be prepared for the excitation test supply. The field cur-rent can now be adjusted in manual control with the field regulator from zero up to nominal current.




6.2. POWER CIRCUIT DESIGN

6.2.1. Rectifier Unit and Overvoltage Protection

The input to the excitation system from the power circuit for the supply of the rectifier unit is pro-tected with semiconductor fuses in each phase and further equipped with an overvoltage protec-tion of the Selen tiles type or with an AC RC-assembly.

The rectifier unit is a fully controlled thyristor bridge whereby each thyristor is provided with it's ownsnubber circuit. Positive and negative field voltage are permitted with a resulting high speed regu-lator response.

The thyristors are mounted on a heat sink cooled by a fan.

With the back-feed information of the regulator's microprocessors the ignition of the thyristor con-trol pulses are calculated. These pulses are amplified and sent via the impulse transfer circuit,being galvanic isolated from the thyristors.

6.2.2. De-excitation Equipment and DC Overvoltage Limiter

The de-excitation facility constitutes a safety system being independent from the thyristor bridgeand regulators.

De-excitation by synchronous machines with AC exciter equipment is performed through interrup-tion of the field circuit via the de-excitation contactor. A polarized voltage-dependent semiconduc-tor and a single-phase rectifier in bridge connection are parallel connected to the field of exciter.So the voltage peaks during the de-energizing process as well as transient voltages caused byshort circuits at the synchronous machine are limited. Further the duration of the de-energizingprocess is reduced by this method.

To spare the contacts of the de-excitation contactor during normal shut down of the unit the thy-ristor bridge is regulated fully into converter mode thus decaying the field current and the contactoris opened after a time delay. During a protection trip this contactor is opened instantaneously andthe field energy dissipated via the voltage-dependent semiconductor.

6.2.3. Field Flashing

Initial excitation during start up of a synchronous generator equipped with a shunt field excitationsystem can only be secured with additional measures since the residual voltage is not sufficient toprovide the energy required.

The station battery via diodes a limiting resistor and a start up contactor delivers the necessaryenergy to the field circuit. During initial excitation this contactor is closed and is opened again assoon as the thyristor unit has taken over the field current. Now the thyristor unit is regulating to theadjusted set value. A typical field current produced by the initial excitation is in the order of 10 % to20 % of the nominal no-load field current at generator rated voltage. The maximum short time rat-ing of the initial excitation in case of faults, depending on internal supervision, is 15 sec.

During test supply whereas the excitation system derives the energy from an excitation trans-former connected to the station auxiliaries an initial excitation is not necessary.

The voltage for field flashing is completely independent from the 125 VDC supply of the THYNE4.




6.2.4. Current Boosting

The energy of the excitation system is taken from the generator terminals. During transient condi-tions (i.e. short circuits) the excitation supply voltage is no more sufficient to maintain the excitationvalue, this circuit is therefore triggered by the activation of boosting rectifier (under 70% of ratedstator voltage) to permit the activation of the excitation ceiling characteristics. The supply of theboosting circuit is taken from the station battery. A limiting resistor keeps the current to the excita-tion ceiling value.The boosting is stopped as soon as the stator voltage reaches 80% of rated stator voltage (byopening of the boosting breaker). The duration of the boosting is given by the excitation ceilingtime.

6.3. AUTOMATIC VOLTAGE REGULATOR AND GATE CONTROL GMR3

6.3.1. Overview

The regulator and gate-control unit GMR3 is a multi-processor voltage regulator for synchronoussingle-phase and three-phase machines with a broad frequency range. It comprises a completevoltage regulator, the firing circuitry for single-phase or three-phase operation and the control logicthat is necessary for the proper operation of an excitation system.

6.3.1.1 Operating Principle

In its basic embodiment, the system comprises a main processor (MRB), 3 sub-processors(Pr.A,B,C), digital and analog inputs and outputs in variable numbers, and a measured-valueprocessing board (SAB) for the electrical quantities of the machine and the gate pulses. Theregulator is structured as voltage regulator with one master (voltage) control loop and one slave(exciter current) control loop.

Matching transformers provide isolation for the actual values (stator voltage UG, stator current IG,exciter current IP, thyristor voltage USYN). They are transformed into low voltages, which a cablefeeds to board SAB. On the SAB board, the measured values are processed for the sub-processors of the PIM unit.

Fig. 2: Block diagram GMR3




Sub-processor C calculates the parameters required to regulate a synchronous machine. Via adual-port RAM (DPR C), the results are transmitted to the main processor MRB. (A dual-port RAMis a memory device which gives access to two processors, independent of each other.)

The main processor contains the software for the voltage loop (automatic operating mode), thelimiters, the additional regulators, and the entire control logic that is necessary for a proper opera-tion. All digital I/O cards and all additional system-specific analog I/O cards are also connected tothe main processor unit. The output value of the voltage loop is transferred to sub-processor B onboard PIM via dual-port RAM DPR B.

Sub-processor B contains the exciter-current loop (manual operating mode). On the basis of theactual field current (recorded via module SAB) and the information provided by the main proces-sor, this loop calculates the firing angle for the thyristor pulses. The firing angle is transferred tosub-processor A via DPR A.

Sub-processor A calculates the firing pulses. Transistors on module SAB amplify the pulses, whicha cable feeds to the firing transformers (one for every thyristor). A switch on the front panel of theSAB facilitates the manual testing of the firing pulses.

Digital inputs and outputs serve to control and process commands, feedbacks, and alarms. Allanalog inputs and outputs required for regulating are available on board SAB. As an optional fea-ture, additional input and output boards may be provided for system-specific tasks.

6.3.1.2 Regulator Assembly

The different regulator boards are built into a 19" rack. At the rear, they are connected by meansof a wiring print. The voltage supply and all external inputs and outputs are connected via front-panel connectors.

The below boards are mounted in one regulator unit:

1 voltage supply NGT (position A1)

1 main processor board MRB (position A2)with memory for program and setting parameters, 1 serial service adapter at the front

1 or several sub-processor boards PIM (from A4 to A9, as required)each with 3 signal processors (A, B, C) and attached program memory

1 or several signal processing boards SAB (A4 to A9, as required)to couple the measured values and to uncouple the gate pulses

1 or several digital input boards DE32 (A4 to A19, as required)each with 32 optocoupler inputs and 32 LEDs

1 or several digital output boards DA32 (A4 to A19, as required)each with 32 relay outputs and 32 LEDs

1 optional digital input/output board SEA (A4 to A19, as required)each with 24 optocoupler inputs, 8 relay outputs and 4 analogue inputs and 16 LEDs

1 actual value pick-up IWKincludes isolating and matching PTs and CTs




6.3.1.3 Scope of Program

The software comprises the operating system and the regulator programs with the setting pa-rameters for the main processor board (MRB) and the different sub-programs for the sub-processor boards (PIM). All programs are stored in EPROMs, all adjustable parameters are storedin EEPROMs.

The operating system provides input and output conversion, coordinates the sequence of theregulator program, the data exchange to the sub-processors, and facilitates communication withthe regulator via a serial interface. Different monitoring functions permit a selective error detection.In addition, the operating system comprises an editor, which serves to work on the regulator pro-grams.

For operating, an operation terminal or a compatible PC may be attached via an RS232-C inter-face on the main processor board.

The sub-programs on the sub-processor board contain the compiling of the measured values andthe calculation of the actual values (processor C), one exciter-current regulator (processor B), andthe gate pulse generation (processor A).

6.3.2. Description of Hardware

The regulator consists of a 19" rack (6HE, 84TE), which is fitted with the printed circuit boardsnecessary to satisfy the system specifications. On the rear of the regulator, all units are connectedvia a wiring print. Additional connections for some modules are made via the respective applicationplug with plug-on wiring prints. The voltage supply and all inputs and outputs are connected bycable via connectors on the front panel.

The following is an overview of the functions of the cards. For details see the respective descrip-tions of the printed circuit boards.

6.3.2.1 Voltage Supply

The regulator requires a 24Vdc supply. The supply is provided redundant, on the one hand fromthe thyristor voltage via a matching transformer and a diode rectifier, and on the other hand fromthe station battery.

Supply to Regulator Electronics

The supply voltage from the redundant supply (nominal value 24Vdc, range 15-36 Vdc) is fed tothe DC/DC converter NGT in the regulator via a front-panel connector. The DC/DC converter canonly be used in position A1 of the regulator. It supplies the voltages needed by the regulator elec-tronics:

5V: supply for all functional groups processing digital signals±15V: supply for all functional groups processing analog signals

On the rear of the rack, these voltages are connected to the individual boards via a wiring print.The regulator ground is connected to the regulator casing.

Supply to Pulse Amplifiers

The pulse amplifiers, fitted near the thyristors, need a supply of 24Vdc. The redundant regulatorsupply is therefore fed to the pulse amplifiers via card SAB. The 24Vdc ground is connected to theregulator ground and the regulator casing.




6.3.2.2 Main Processor Board MRB

The operating system with the main regulator program is on this board. The board has an INTELprocessor and EPROMs for programs, in addition to the working memory, as well as an EEPROMto store site dependent parameters. The board can only be used in plug-in position A2 of theregulator. An RS232-C serial interface adapter is located on the front panel, in order to connect anoperation terminal or a compatible PC for maintenance purposes.

6.3.2.3 Sub-Processor Board PIM

The board contains 3 independent INTEL signal processors (A,B,C) with corresponding periphery.Each of the processors serves a precisely defined task which is in line with the correspondingsoftware. Up to 4 sub-processor boards can be used in one regulator unit (in positions A4 to A9,as required). The PIM boards are numbered consecutively, starting at 0, and the number must beset with the selector switch on the board.

Dual-port RAMs are used for data exchange with the main processor. They are memories that 2processors can use for writing and reading. Consequently, the processors are uncoupled. Thesub-processors can work independent of the main processor, which means that the sub-processors continue to operate, also in case of a main processor board failure.

6.3.2.4 Signal Processing Unit SAB

The SAB board can only be used together with sub-processor board PIM. The two boards areconnected on the back, via a plug-on wiring print. The system signals are connected via 2 front-panel connectors. A maximum of 3 SAB boards may be used in one regulator unit (in positions A4to A9, as required).

Print SAB serves for the below tasks:• to read in actual values• to read in 6 free analog values• to output gate pulses• to enable manual setting operation

CAUTION

All analog signals and gate pulses are electrically connected to the regulator ground! Analog sig-nals may only be connected via isolating transducers or transformers.




Actual Values

A maximum of 7 measured values, required for regulating and gate-control, are read in via isolat-ing transformers:• synchronizing (thyristor) voltage US1 (L1-L3)• synchronizing (thyristor) voltage US2 (L2-L3)• stator voltage UG1 (L1-L3)• stator voltage UG2 (L2-L3)• stator current IG1 (L1)• stator current IG2 (L2)• exciter current IP1

The measured physical values are filtered and converted into a form which the PIM board can pro-cess. In addition, different input-signal levels can be matched, when soldering resistors to printSAB.

Single-phase or three-phase signals can be processed. The three-phase signals are recorded viatwo measuring channels. When measuring single-phase signals, the second channel for the re-spective measured quantity is not used. The exciter current is always transferred as direct-voltagevalue via one channel.

Dependent on site conditions the following combinations are possible:

Three-phase rectifier bridgeUS1: thyristor voltage L1-L3US2: thyristor voltage L2-L3

Single-phase rectifier bridgeUS1: thyristor voltage L-NUS2: no used

Three-phase machine with three-phase measurementUG1: stator voltage L1-L3UG2: stator voltage L2-L3IG1: stator current L1IG2: stator current L2

Three-phase machine with single-phase measurementUG1: stator voltage L1-L3UG2: no usedIG1: no usedIG2: stator current L2

Single-phase machineUG1: stator voltage L-NUG2: no usedIG1: stator current LIG2: no used




Free Analog Values

Board SAB has 6 analog inputs for site applications, which can be used to implement user-specifictasks. DC or AC signals can be processed, which must be connected via external isolating trans-formers. Via input circuitry, voltage divider, rectifier with add-on offset and low pass, they are con-verted into a signal 0...+5V. Soldered resistors facilitate an adjustment to different input signal lev-els.

The software uses the 6 analog signals via variables V511 (ANA1) to V516 (ANA6).

Pulse Outputs

The gate pulses, required to control the thyristors of the power rectifier, are amplified on the SABboard and supplied to the upper front-panel connector, together with the 24Vdc auxiliary voltagefor the pulse amplifiers. A maximum of 6 pulses is available.

Selectable by jumpers on the printed board, either pulse amplifiers (transformers with amplifiersconnected in series) or pulse transformers (without amplifiers) can be connected. Thyristor bridgescan only be connected in parallel when pulse amplifiers are used. Triggering gate pulses can beprevented when using the gate pulse blocking relay on the board.

Front-Panel Switches

Switches on the front panel enable manual setting operation. When switch "HST" is moved to po-sition "1", the control angle of the thyristor bridge can be adjusted manually via control key "±". Theset firing angle can be measured at measuring sleeve "U" (0...5V correspond to 0...180°).

During manual setting operation, the gate blocking relay is ineffective, and gate pulses are trig-gered independent of the position of the gate blocking relay.

6.3.2.5 Actual Value Pick-Up IWK

This board is mounted behind a protection cover on the back of the regulator unit. It contains thenecessary devices to match and isolate at maximum 8 measured actual values. The external sig-nals are connected to a terminal strip on the IWK. The internal signals are connected to the SABby a cable for further processing. The main components on the IWK board are:

2 PTs for the synchronizing (thyristor) voltages US1, US22 PTs for the stator voltage UG1, UG22 CTs for the stator current IG1, IG22 CTs and a rectifier for the exciter current IP1, measured at AC-side of the thyristor bridge, or

alternatively one DC/DC converter for the supply of a hall-sensor type transformer to measurethe current IP1 in the field circuit of an exciter machine.

1 PT optional, for the net voltage UN.

4 of the 6 free analog values (ANA1, ANA4, ANA5, ANA6) are passed through the IWK unit with-out further processing. 1 input (ANA2) is reserved for the connection of the net voltage and 1 input(ANA3) is reserved for the field voltage (to be measured by a hall-sensor type transformer).




6.3.2.6 Digital Input Board DE32

The print has 32 digital inputs. Each of the inputs is passed over optocouplers and displayed byLEDs. Two inputs each have a common potential. All connections are wired by cable to the termi-nal strip via a front-panel connector. 24Vdc (range 15-36Vdc) are used as coupling voltage. In thebasic configuration the regulator is equipped with 1 board DE32. A maximum of 16 input boardscan be used (in positions A4 to A19, as required).

The software reads the inputs of the first board via variables E0 to E31. The inputs of additionalboards are numbered consecutively (E32...).

6.3.2.7 Digital Output Board DA32

The print has 32 digital outputs. Each of the outputs is passed over a printed-board relay and dis-played by LEDs. Two outputs each have a common potential. All connections are wired by cable tothe terminal strip via a front-panel connector. 24Vdc are used as query voltage. In the basic con-figuration the regulator is equipped with 1 board DA32. A maximum of 16 output boards can beused (in positions A4 to A19, as required).

The software actuates the outputs of the first board via variables A0 to A31. The outputs of addi-tional boards are numbered consecutively (A32...).

6.3.2.8 Analogues Output Board AA8

This print is only used when needed for site-specific applications. The print has 8 analog outputs,which can be set individually as voltage or current sources. All outputs have one common ground.The output signals can be measured on the front panel via testing sleeves. All connections arewired to the terminal strip with a shielded cable, via a front-panel connector. A maximum of 16output boards can be used (in positions A4 to A19, as required).

The software actuates the outputs on the first board via variables Y0 to Y7. The outputs of addi-tional boards are numbered consecutively (Y8...).

The following signal ranges can be selected individually for every output via plug-in jumpers:±10 V ±5 / ±10 / ±20 mA

6.3.2.9 Special Input / Output Board SEA

This print is only used when needed for site-specific applications. The print has 24 digital inputs, 8digital outputs and 4 analog inputs. each of inputs is passed over optocouplers and displayed byLEDs. Eight inputs each have a common potential. Each of outputs is passed over a printed-boardrelay and displayed by LEDs. Two outputs each have a common potential. Four analog inputs ei-ther ±10 V or ±20 mA. The signal range has to be selected via plug-in jumpers.

6.3.3. Description of Software

The software comprises the program elements:• operating system with editor and monitoring functions• regulator program with site-specific setting values• sub-programs for the sub-processors used

The operating system and the regulator program run on the main processor board MRB. The sub-programs for the sub-processors of board PIM are separate functional units. They handle certaintime-critical tasks, which the main processor cannot handle (e.g. gate pulse generation, actualvalue calculation, ...).




6.3.3.1 Operating System ECS

The operating system ECS runs on main processor board MRB. It provides the input and outputconversion, coordinates the execution of the regulator program, as well as the data exchange tothe sub-processors, and it facilitates communication with the regulator via the serial serviceadapter on the main processor board MRB. Different monitoring functions permit a selective errordetection. In addition, the operating system comprises an editor, which helps to generate, changeand list user programs.

Basically, the regulator is therefore a freely programmable control and regulating system, whichcan be programmed in a language using functional blocks. With this language, pre-defined soft-ware modules (functional blocks) are connected via a linking list to a user program. The operatingsystem comprises a module library with a large number of analog and digital modules, with opti-mized running times. The modules facilitate the implementation of regulating and control tasks.

Program Execution Control

A micro-processor can implement the individual functions only consecutively (serially). The timerequired to run one program one time is called "execution time". Once the end of a program isreached, the whole process is started again. Since the system is used for regulating tasks, it isnecessary to run certain programs at precisely defined time intervals (program cycle time). This isachieved by starting them every 10 msec, for example. The entire execution time of a programmust, of course, be shorter than the program cycle time.

The maximum possible program size is limited by the program cycle time. In order to be able touse also comprehensive programs when cycle times are short, a user program may be divided intoup to 8 components (tasks) with different requirements on execution speed. An individual constantcycle time Ta (1 to 65535 ms) may be selected for every task.

The tasks are numbered 1 to 8, with the lower-numbered tasks having a higher priority and shortercycle times than the higher-numbered tasks. Tasks with higher priority may interrupt tasks withlower priority. As a result, several tasks may be operated in a "quasi parallel" mode. During breaksbetween tasks, the service interface, and alike, are operated. While running the user program, theparameters may be set.

Classes of Variables

The user program on the main processor board is programmed in a language that has been as-similated to conventional regulating and control technologies, i.e. individual elements (modules)are connected to create a global structure. Discreet circuit engineering uses wires for the connec-tions, here memory locations are used. In the system, different connecting elements ("variables")are available for the individual applications. They are distinguished according to "classes of vari-ables". In line with their area of application, the different classes of variables have different rangesof values and formats for display.

The software uses 9 classes of variables in 3 formats for display.

Digital Variables:

E: digital input variables (from input board DE32)A: digital output variables (to output board DA32)I: digital internal variables (connecting variables)C: digital internal constants




Analog Variables:

X: analog input variables (from analog input AE8)Y: analog output variables (to analog output AA8)V: analog internal variables (connecting variables)P: analog internal constants

Time Constants:

T: internal time constants

The variables of a class are distinguished by numbers behind the letters (starting at 0, e.g. E0,V251, ...).

Formats for Display

The values for the individual variables are shown on the user screen (PC, operation terminal) asfollows:

Digital Variables/Constants (E,A,I,C):

L, H (0, 1 on operation terminal)

The range of values comprises only the two values L (low, log. 0) and H (high, log. 1). If, for adigital parameter, the value U (undefined) appears on the screen, this is most likely due to a hard-ware fault.

Analog Variables/Parameters (X,Y,V,P):

-16.0000 to +15.9995 (p.u. format)

The following conversion applies to analog inputs and outputs X (AE8) and Y (AA8):

-1.0000 is the negative limit of the range (e.g. –10 V, -20 mA)0.0000 is 0V, 0mA+1.0000 is the positive limit of the range (e.g. +10 V, +20 mA)

The range of the analog board is set on the board by means of plug-in jumpers (see description ofrespective board).

If a value of +2.0000 is set for an analog output, it will only output the positive limit of its range(e.g. +10V, corresponds to ceiling voltage of operation amplifiers). Within the system, the pa-rameters V and P can, however, have values between -16.0000 and +15.9995.

Time Constants (T):

0 to 65535 (decimal format)

With this parameter class, all internal logic masks of the system, all communication addresses withsub-processors and the unchangeable time constants are determined. When using them as timeparameters, the set value should be understood to be a factor of the cycle time.

Example: A parameter T20 is assumed for Task 1. The cycle time for Task 1 is assumed tobe 2 msec, 140 was entered as the value for T20. The set time is therefore 140 x 2 msec =0.24 sec.




Representation of Variables Within the Operating System

Within the system, the digital variables E, A, I and C are represented by "bytes" (of 8 bits). Bytevalue 0 corresponds to logical value L, byte value 255 corresponds to logical value H. All othervalues are displayed as U (undefined).

The analog variables X, Y, V, P and T are represented by "words" (of 16 bits). On a service de-vice, parameters X, Y, V and P are displayed in the "p.u." (per unit) format (e.g. +01.0000), pa-rameter T in decimal format (e.g. 30100). The values have the following meaning:

internal system representation decimal format p.u.-format (two's-complement) (T) (X,Y,V,P)

32767 = 32767 = +15.9995 1 = 1 = +00.0005 0 = 0 = +00.0000 -1 = 65535 = -00.0005 -32768 = 32768 = -16.0000

The computer does not make any difference between the classes of analog variables. This distinc-tion only serves for a clearer display.

Memory Areas

The operating system is stored on EPROMs. The site-specific setting values and the regulatorprogram are stored on EEPROMs and can be changed at all times.

The working memory (RAM) of the system is divided into 3 areas, numbered 0, 1, 2. Areas 0 and 1are assigned for the regulator program, area 2 for the variables and setting parameters. At everyre-start of the system (reset, voltage failure) the application program which is stored in EEPROMwill be copied to the SRAM and will be started. The setting values (from the parameter EEPROM)are loaded into the respective areas of the working memory.

Distribution of the Parameters among the Nonvolatile Memories

P, T and C constants are stored on one EEPROM, together with the program. They are used forbasic settings and should not be changed. The variables beyond V800 and beyond I1000 are re-served for setting parameters and stored on EEPROMs.




6.3.3.2 Main Regulator Program

The regulator allows automatic and manual regulation. The regulator structure is embodied asvoltage regulator with two control loops (master - slave) and regulates the generator voltage to anadjustable voltage set value.

The master (for voltage regulation) consists of a PI(D) regulator with integrator feedback and con-trols the slave (for exciter current regulation) with P(I) characteristics. The above structure pro-vides for a high control speed, as well as a high stability at all load points. A large number of limit-ing and additional regulators, some of which are optional features, permits a high degree of ad-justment to all requirements.

The main regulator program is executed by the main processor MRB. It was programmed, usingthe modules that are contained in the module library of the operating system ECS. The regulatorprogram contains the voltage control loop, all limiting and additional regulators, as well as the logiccontrol sequences and their monitoring functions, which are necessary for a faultless operation ofthe complete excitation unit. The secondary exciter current loop is a component of the sub-program on sub-processor board PIM. The different functions are activated in keeping with sitespecifications, depending on the task in hand.

The total scope of the program depends upon the configuration of the system and is thereforevariable. A description of the individual regulator parameters can be taken from the drawings anddescriptions which are supplied with the system documentation.

The main program is divided into 8 tasks, and the variables into groups of numbers.

Division of Tasks

The below table gives an overview of the division of the regulator program into the individual tasksand the corresponding cycle times.

Task CycleNo. Time Program Component

1 2ms voltage regulator2 4ms undelayed field current limiter, detection of the inputs for protection3 20ms load angle limiter4 50ms other limiting regulators5 50ms analog value monitoring

site-specific analog processing6 50ms logic control7 100ms set value generation

reactive load regulationregulator operation messageserror messages

8 300ms parameter exchangetime base conversion




Groups of Numbers for Variables

The variable numbers are split up into different groups, depending on their purpose of use.

e.g.: V0 - V199 analog variables for regulatingI0 - I199 digital variables for regulating

The variable numbers beyond V800 and beyond I1000 are reserved for setting parameters andare stored on an EEPROM.

V800 - V899 analog parameters

V900 - V949 time parameters 1.0000 = 1 secV950 - V999 time parameters 1.0000 = 100 sec

I1000-I1015 variables used to connect limiters and regulator add-ons

Normalizing Measuring Values

The regulator software uses normalized values for calculating. In general, every physical measur-ing value is related to its rated value and represented as p.u. (per unit) value.

Example: The machine voltage is represented by variable V501. In case of a rated voltage atthe machine terminals, V501 has the value 1.0000.

6.3.3.3 Regulator Sub-Programs

Various functions, which the main processor cannot handle, are implemented by sub-processorson the PIM board. The regulator has a minimum of one PIM board with 3 sub-processors. Theseprocessors serve to calculate the actual value, to regulate the exciter current and to generate thegate pulses.

The data exchange with the main processor on board MRB is by means of DP-RAMs. A series ofparameters and variables serves to complete the configuration of the individual sub-programs, aswell as to monitor them.

Gate Pulse Generation

A gate-control unit serves to generate firing pulses for thyristors, in order to produce a variabledirect voltage from an alternating voltage (thyristor voltage). The thyristor voltage can be single-phase or three-phase, and the frequency can also be variable within a broad range (e.g. in case ofa permanent magnet generator). The direct current, generated at load (field, rotor), is smoothedsufficiently on account of the inductivity of the load.

Control angle α is the control input of the gate-control unit. The control angle (firing angle) is de-fined as the position in time of the firing pulse to the phase position of the phase voltage. De-pending upon the thyristor bridge, which is attached to the firing circuitry, the output voltage isgenerated via a certain control law, in accordance with the given firing angle.

In general, a control angle α = 0° is the rectifier end position (maximum possible positive outputvoltage). A control angle α = 90° results in an output voltage with a value 0, and the maximumpossible control angle must be less than 180° (inverter end position, negative output voltage).

The control angle is measured from the natural firing point. This means that the gate-control mustknow the current phase relation of the phase voltages. In addition, it must be possible to calculatein advance at what instant a certain phase relation is reached. It is therefore necessary to knowthe frequency of the phase voltage. (Synchronizing the firing pulses to the thyristor voltage).




The gate-control consists of processor A, with the corresponding circuits on sub-processor boardPIM and the input and output circuits on the SAB board. It is suited for applications in three-phasesystems (6 thyristors) and in single-phase systems (4 thyristors). Processor A calculates the firingpulses for the thyristor bridges.

For processor A, the two phase to phase synchronizing voltages US1 (L1-L3) and US2 (L2-L3) areavailable as measuring values and to synchronize the firing pulses (in case of single-phase sys-tems only US1 is used). Each of these voltages is filtered on board SAB and transformed into afrequency that is in direct proportion to the instantaneous voltage value, by means of voltage-controlled oscillators (VCO). The pulses of that frequency are counted in a counter module of sub-processor board PIM, which the processor processes periodically. This process corresponds to anintegrating compilation of the measured values.

The software simulates the vector of the synchronizing voltage (thyristor voltage). It serves as ref-erence for the natural firing point, as well as for the frequency. The actual firing point of every thy-ristor is derived from firing angle α, which the field current regulator (processor B) computes. It canbe calculated from the sum of firing angle α and the natural firing point that is assigned to the thy-ristor.

The rectifier limit defines the lower limit of the working range of firing angle α (rectifier operation),while the inverter limit defines the upper limit (inverter operation).

For every thyristor branch of a fully controlled bridge, a firing pulse is generated at the corre-sponding HSO (high speed output) of processor A, at the actual firing instant. The length of thefiring pulse depends upon the frequency of the synchronizing voltage.

The computation method works independent of sense of phase sequence and frequency, so thatthe capacity of processor A is the only limiting factor. The pulse calculating program runs synchro-nously to the thyristor voltage, at a multiple (synchronizing coefficient m) of the thyristor frequency,i.e. the measurements and calculations are made m times in every period. The synchronizing coef-ficient satisfies the following condition:

m = 6·i where i = 1,3,5,7,9,11

The calculations require a certain time, which limits the synchronizing coefficient m in the down-ward direction; yet, the calculations should be repeated as often as possible. This results inchanging the synchronizing coefficients within the operating range of the gate-control set of thethyristor bridge.

On the basis of the calculating capacity, the maximum admissible frequency of the thyristor volt-age is 440 Hz when m = 1. Together with the possible synchronizing coefficients, the programcycle time is in a range of approximately 0.4 to 1.3 msec, depending on the thyristor frequency.

The gate-control set can operate three-phase bridges with positive or negative phase sequence, orsingle-phase bridges.




Three-Phase Rectifier Bridge

It consists of 6 thyristors; accordingly, 6 firing pulses must be generated. The distance betweenthe pulses is 60°.

The phase to phase voltages US1 (L1-L3) and US2 (L2-L3) are measured. The natural firing pointis at 30° after zero passage of the corresponding phase voltage. Double pulses at a distance of60° are generated during rectifier operation (firing angle α = 0...90°), i.e. for a commutation, thesetwo thyristors which shall conduct the current always receive a firing pulse at the same time. Dur-ing inverter operation (firing angle α = 90...180°), only single pulses are generated, for reasons ofsafety.

Single-Phase Rectifier Bridge

It consists of 4 thyristors. 4 firing pulses are generated, of which 2 pulses must always be set atthe same time (i.e. 2 pulse pairs are generated, with a distance of 180°). The alternating voltageUS1 (L-N) is measured. The natural firing point occurs at zero passage of the phase voltage.

Manual Setting Operation

The firing angle may be set manually for testing purposes. The switches for manual operation onboard SAB act on the digital inputs of processor A. The instantaneous value of the firing angle isoutput as a signal with modulated pulse-width at an HSO (high speed output) of the processor,and can be measured at measuring jacks.

Exciter Current Regulator

The regulating algorithm of voltage regulator GMR contains a secondary exciter current loop,which can also be used for manual-operation purposes. This loop with P(I) characteristic is imple-mented in sub-processor B. The P and I behavior can be configured individually or switched off.

The set value for the exciter current is supplied by the main processor. The value measured for theexciter current is filtered on board SAB and transformed into a frequency that is in direct proportionto the instantaneous value of the voltage, by means of a voltage-controlled oscillator (VCO). Thepulses of the frequency are counted in a counter module of sub-processor card PIM, which thesub-processor evaluates periodically. The exciter current value, determined by the software in thismanner, is filtered by a 1st- order low pass (PT1) with adjustable time constant and supplied to theregulating algorithm as actual value.

The regulator output is the firing angle, which is transferred to the gate-control in processor A. Theregulating algorithm in processor B runs synchronously to processor A and has therefore the samecycle time as the former.

Different operating modes can be configured via the input parameters:

• PI regulation, the P and I shares can be set individually• P regulation, the P share can be set (I share = 0)• Loading the integrator with a preset value• Setting the firing angle directly by main processor




Free Analog Values

Six analog inputs are available via board SAB. They are used for system-specific tasks. Everyanalog value is transformed into a signal 0...+5V on board SAB. Sub-processor B reads in the val-ues via its analog inputs, with a resolution of 10 bits. In addition, they are filtered by the software(1st-order low passes, PT1) and supplied to the main processor via the DP-RAM. The filter-timeconstants can be set individually.

Analog value 1 (V511 ANA1) is available in the main processor with a time resolution of 4 msec, allothers (V512 - V516) with a resolution of 100 msec.

Actual Value Measurement and Computation

Processor C calculates the values required for regulating and optional power system stabilizing(voltage, current, frequency, rotor angle, power, stabilizing signal, ...), from the measured genera-tor or motor quantities. The calculation method is equally suited, both for single-phase or three-phase machines (turning left or right) and covers a broad frequency range (see Technical Data).The program has a cycle time of 1 msec. The following configurations are possible.

• 3-phase systems with 3-phase measurement:stator voltages UG1 (L1-L3), UG2 (L2-L3), stator currents IG1 (L1), IG2 (L2)

• 3-phase systems with 1-phase measurement:stator voltage UG1 (L1-L3), stator current IG2 (L2)

• 1-phase systems:stator voltage UG1, stator current IG1

These measured values are filtered on board SAB and transformed into a frequency that is in di-rect proportion to the instantaneous value of the filtered quantities, by means of voltage-controlledoscillators (VCO). The pulses of the resulting frequency signals are counted in counter modules ofthe sub-processor board PIM, which the processor processes periodically. This process corre-sponds to an integrating compilation of the measured values.

Tolerances of electrical parts in the measured-value processing may cause minor differences inamplification and zero points of the signals. They result in an asymmetry of the internal vectors. Incase of a zero shift, an asymmetry occurs at basic frequency, in case of amplification differences,an asymmetry occurs at double frequency of the measured voltage. These component-dependentasymmetries have no impact on the overall functioning. They only cause a minor ripple in the thy-ristor output voltage and may be compensated, if necessary, by means of parameters V810 toV812 for the stator voltage, or V814 to V816 for the stator current.




6.4. AUTOMATIC VOLTAGE REGULATOR

6.4.1. Voltage Regulator (Automatic Mode)

The microprocessor controlled voltage regulator of the GMR3 family represents the heart of theexcitation system.

The regulator and the grid regulator unit are a multi-processor voltage regulator for synchronousgenerator with a wide operating frequency range. It contains the complete voltage regulator withthe necessary limiters and additional regulators, a grid regulator unit for single or three-phase op-eration and the control logic necessary for the proper operation of an excitation system.

The system is of modular design and consists of altogether 4 processors, the digital and analogueinputs and outputs, a signal processing module for the electrical machine data and a digital gridregulator unit.

The voltage supply is always performed redundant. At standstill the regulator is supplied from thestation battery. In addition a second supply is provided as a "backup" from the thyristor bus. Thisbackup supply takes over via de-coupling diodes without interruption the supply for the regulatorduring operation.

Functional Principle:

The voltage regulator operates with two regulating loops. The first loop (for voltage regulation) withPID structure and internal integration feedback controls follow-up of the second regulating loop (forfield current regulation) with a P(I) characteristic. Due to this two-stage design a fast regulatingdynamics as well as high stability during all operating- and load conditions is achieved.

The actual measured values are converted via potential free interposing CT's for the processing ofthe sub-processor.

Program Volume:

The software contains the operating system and the regulating program with the setting parame-ters on the main processor module and the various sub-programs on the sub-processor module.System- and User software and plant specific parameters are stored in an EEPROM, which can bemodified according to requirements.

The operating system carries out the input and output conversion, co-ordinates the sequence ofthe regulating- and sequencer program and data exchange with the sub-processors and enablescommunication of the user with the regulator via a serial interface.

All setting-, calibration- and set value potentiometers are part of the software without contacts andtherefore require no maintenance.




The following limiters and additional features are provided in the standard design:

• Max. and min. field current limiter with an instantaneous and delayed response• Overfluxing limiter (V / Hz)• Generator voltage limiter• Stator current limiter with current dependent delay (inverse time) for capacitive and inductive

generator operation.• Under excitation limiter• Line droop compensation• Diode fault monitoring on AC exciter machines with flywheel diodes for open circuit or short

circuit• Soft-Start feature, i.e. start the initial raising of the generator voltage with a defined rate of rise

without hunting

In order to provide utmost safety during operation the system is provided with extensive hard- andsoftware supervision features.

• Self-monitoring of the 4 processors• Monitoring of the supply voltages• Watchdog functions on the individual printed circuit boards.• Self-monitoring of the most important variables• Test switch on grid control unit for tests with open regulating circuit

6.4.2. Field Current Regulator (Manual Mode)

For manual operation via the (internal) regulating loop the field current is regulated according tothe adjusted set value. The potentiometer for the current regulator is again part of the softwareand also requires no maintenance.

To increase availability for this mode no limiters are effective with the exception of the field currentset value is limited to a maximum value of "set value field current regulator upper range".

6.4.3. Automatic Follow-Up Change Over between Voltage Regulator andField Current Regulator

A smooth transfer from voltage regulator (automatic mode) to field current regulator (manualmode) during operation is achieved either manual or automatic. Automatic change over takesplace on faults in the voltage regulator system, e.g. failure of the generator voltage set value.Transferring from field current- to voltage regulator mode can only be performed manually.

A follow-up regulator continuously adjusts the respective other operating mode so that in eitherway always balanced conditions are present. Thus no differential voltage meter is necessary andtherefore not provided. When in manual mode the set value falls short of or is exceeded a changeover is blocked.




6.4.4. Operation, Indication and Digital Sequencer

Digital sequencer, monitoring and alarm annunciation are integrated in the µP-system as part ofthe software and are therefore provided with the same reliable supply voltage as the regulator.However the most important trip outputs are separate for safety reasons and are therefore inde-pendent from the function of the microprocessor.

For control, monitoring and alarms following functions are specified:• Digital sequencer for proper field flashing, current boosting and de-excitation including opera-

tion of all necessary contactors• Input- and output signal processing (with potential free interface to the station control system)• Monitoring of the excitation as well as alarm and trip output signals• Control and indication unit for local operation• Local indication via LC-display for:

− Generator voltage− Generator current− Field current− Generator active power− Generator reactive power

• Indication of further measured values via the LC-display of the control unit when called upon ispossible

• This control unit consists of a film keypad for the operating commands and a four row LC-display for alarm annunciation and measured values.

• Excitation alarms are stored locally and indicated with the correct time sequence on the LC-display.

• Several test- and simulation facilities for commissioning and maintenance

6.4.5. Software package WINOPER

For operation, maintenance and diagnosis the software package WINOPER is available. It allows,by graphical display on a PC, a complete overview and user friendly operation. Furthermoremonitoring of analogue and digital variables is possible in different ways. Thus, the facilities of theintegrated LC-display and operation panel are considerably extended.

The PC is simply connected to the GMR3 processor board via serial interface RS232. WINOPERenables monitoring or change of plant-specific parameters. The modified parameters can bestored in an EEPROM.




7. INTERFACE OF EXCITATION SYSTEM

7.1. EXCITATION POWER CIRCUIT

7.1.1. Excitation Supply (to exciter)

Signal name EXCITREXCIT:The output of the excitation system for the supply of the field winding is carried out via terminals-X01/3 (positive current) and -X01/4 (negative current).

7.1.2. Excitation AC Supply and Excitation Test Supply

Signal name EXCIT PWRSPLY and EXCIT TESTSPLY:The AC power supply of the excitation system is connected to terminals –X01/5 and –X01/9 andthe test supply has to be connected to the terminals –X01/8 and –X01/12. There is a manual op-erated link, which makes the connection of the chosen supply to the rectifier-bridge.

7.1.3. Field Flashing and Current Boosting

Signal name FLASH/BOOST PWRSPLY:For the field flashing and the current boosting circuit the battery supply 125 Vdc (2) has to be con-nected to the terminals–X01/1 (plus) and –X01/2 (minus).

7.1.4. CT / PT and Actual Measured Value Connections

Signal name AVR VOLTMEAS1:The actual measured values of the generator voltage and current is applied as three phase. Theactual measured values connection can be with either a clockwise or anticlockwise phase rotationwhereby the former is preferred.

CAUTION

The correct allocation of the current vectors and voltage vectors has to be strictly observed!

The three phase actual value of the stator voltage L1, L2, L3 has to be connected to the terminals–X10/02, 03, 04.Signal name AVR VOLTMEAS2:In case of optional dual channel regulator, for redundancy the actual value has to be connected tothe terminals –X10/06, 07, 08.Signal name MEAS CURRMEAS:The phase currents from CT's L1 and L2 are allocated to terminals –X10/02 (→) and –X10/01 (←)for L1 and terminals –X10/04 (→) and –X10/03 (←) for L2.For the optional energy meter or transducers with analogues output signals for active and reactivepower, stator current and power factor also the third phase form CT is needed, this will be con-nected to terminals –X10/06 (→) and –X10/01 (←).

Note: -X10/02 (→) means, the current is entering terminal –X10/02 of the excitation system-X10/01 (←) means, the current is leaving terminal –X01/02 of the excitation system




8. LOCAL OPERATION

8.1. Introduction

The ELTERM user interface is integrated in the digital voltage regulator GMR3 and provides easylocal operation along with indication of all generator quantities and vast alarm indication facilities.All reference values, as well as the regulator settings can be changed with the ELTERM.

The main features of the ELTERM are:• On-line display of the system status in plain language• 8 keys provide all direct local operation commands necessary• Menu guided service and maintenance functions• The most important actual values are displayed in physical quantities.• All actual values are displayed in per unit values.• All internal reference values and regulator settings can be inspected and changed on-line in

an easy, menu driven way.• Two level password access prevents from unauthorized changes of parameters.• 96 individual alarm messages provide precise trouble shooting information.• The latest 104 alarm events are registered in their sequence of occurrence.• Automatic display of self-supervision functions in case of an AVR failure, indicating the defec-

tive hard- or software component.

The easy, menu guided operation and the status display in plain language result in a significantimprovement compared to conventional user interfaces. All necessary operation procedures aswell as all parameter modifications can be carried out with the ELTERM. Hence no additional ter-minal or a PC are necessary for operating or servicing an excitation system equipped with a GMR3digital regulator.

The alarm registration of 96 different individual alarms, storing the last 104 events in their se-quence of occurrence provides a very precise trouble shooting information.

CAUTION

Any regulator-manipulation with the ELTERM or a PC constitutes an operating risk for the gen-erator in operation! The staff responsible for the operation of the generator must be contactedprior to any such intervention!

The manufacturer of the terminal does not assume any liability for any possible damage or oper-ating stoppage!




8.2. Description of Functions

8.2.1. Basic Screen - Main Menu

A nine-pole cable connects the GMR3 user terminal to the RS 232 C interface of the MRB card ofthe GMR3 regulator. This connection also serves to supply the terminal.

After connecting the ELTERM to the MRB-board, the basic screen will appear, showing the statusof the voltage regulator/excitation system, as well as the most important generator quantities intheir physical values, if the program on the MRB card is running.

An example of the basic screen is shown below:

Stator voltage, stator current, power factorGenerator active power (MW), reactive power (MVar)Excitation field currentStatus display line

In case of a failure of the GMR3 soft-or hardware, or if the program on the MRB card is not run-ning, the respective error message will be displayed instead of the basic screen.

All possible status messages are shown in the table overleaf. All messages that apply to the actualstate of the excitation system will be shown. Some status messages will ‘turn off’ the display of thegenerator actual values. Those status messages are marked with ‘off’ in the column actual values.If non of those messages is displayed, the generator (stator) voltage, the generator (stator) cur-rent, power factor, active and reactive power, as well as the field current are displayed online.

A ‘+’ related with active power indicates active power delivery, a ‘-‘ active power consumption. A ‘+’related with reactive power (MVar) indicates reactive power delivery (lagging Vars, overexcitedoperation) , a ‘-‘ reactive power consumption (leading Vars, underexcited operation).

After pressing the MENU/ENTER key the main menu will appear. It consists of 5 menu items:

Advice: Use the scroll up key or scroll down key whenever the scroll up symbol ↑ orthe scroll down symbol ↓ appears, in order to scroll to further menu items.

Pressing 1,2,3,4 or 5 on the keyboard will activate the respective function or call up the respectivemenu. The ESC key will return you to the basic screen.

102V 0.79A +.85+134W -37VArField: 12.3A AlarmOn Rem Auto-VAR

2 Actual Values ↑3 Regulator Settings4 Maintenance5 Terminal Mode

1 Alarms, Trips2 Actual Values3 Regulator Settings4 Maintenance ↓




Status Display:

The status display covers the following static or transient states of the excitation system:

N° Status Comment ActualValues

1 Off Excitation System is off. off

2 On Excitation System is in operation.

3 Ready Excitation system is ready to be turned on. off

4 Start Excitation system is starting.

5 Stop Excitation system is stopping.

6 AUTO AVR is in automatic voltage regulation mode.

7 MAN AVR is in manual, field current control mode.

8 Loc AVR is switched to local. Commands given at theELTERM panel will be accepted.

9 Rem AVR is switched to remote. Commands fromremote will be accepted.

10 pf Power factor control is superimposed on theautomatic voltage regulator.

11 VAR Reactive power (Var) control is superimposed onthe automatic voltage regulator.

12 Standby This regulator channel is standby, ready to takeover from the active channel.Only with dual channel regulators.

off

13 Alarm There is an alarm related to the excitation sys-tem or AVR. Check the alarm list by pressing theENTER key and 1 for the Alarm Menu.

14 Excitation Trip! An internal excitation system - AVR failurecaused an excitation trip. Check the alarm list bypressing the ENTER key and 1 for the AlarmMenu.

off

15 Channel Failure! There is a failure related to this regulator chan-nel. A changeover to this channel is not possible.Check the alarm list by pressing the ENTER keyand 1 for the Alarm Menu.Only with dual channel regulators.

off

16 External Prot. Trip An external protection trip is active. The excita-tion system cannot be started.

off




8.2.2. Alarms, Trips

When selecting this menu item, an alarm list of the latest 104 alarm events will be created. Fouralarms will be displayed on one screen, starting on top with the latest alarm event on top of thedisplay. The sequence of display is according to the sequence of occurrence, no matter if thealarms are still active or not.

A blinking asterix on the left of the alarm message indicates that the alarm is active.

An arrow ↓ at the right of the alarm message in the bottom line indicates that there are furtheralarms registered in the list. By pressing the scroll down ↓ key the next alarm message will be dis-played. Scrolling down by the scroll down ↓ key means to go back in time.

An arrow ↑ at the right of the alarm message in the top line indicates that a more recent alarm canbe displayed by pressing the scroll up ↑ key.

After checking the alarm list you can return to the main menu by pressing the ESC key. Beforeleaving the alarm menu, you can choose to accept the alarm list by pressing the ENTER key. Ifyou do so, all alarms that are no longer active will be deleted. Pressing the ESC key will leave thealarm list unchanged.

latest alarm/trip

blinking asterix: trip is still active

press scroll down key for messages registered before

The alarm events themselves are stored in the MRB board of the GMR3 voltage regulator with aresolution of 100ms. When calling the alarms, trips function on the ELTERM panel, the alarm list istransferred from the MRB board and displayed on the screen. The alarm list is permanently up-dated, so the information on the screen is always the latest and actual information.

8.2.3. Actual Values

When selecting this menu item, the most important operating parameters of the synchronous ma-chine are shown as ‘per unit’ values, which are related to the nominal values of the synchronousmachine.

The display shows 2 values at the same time. 2 lines are available for every parameter. The firstline gives the internal designation of the parameter (e.g. V500) and its meaning in plain language(e.g. Excit. Current). The internal designation helps to follow the variable in the regulator diagrams.The second line shows the present value of the variable. Since the displayed parameters are readcontinuously from the regulator, the data always reflect the most up-to-date values, which are be-ing processed in the regulator at any given time.

By actuating the scroll key, the next parameter is displayed that is contained in this menu item.

start overtime trip thyr. current fail∗thyristor fuse fail∗m.c.b. tripped ↓




The parameter that is selected with the cursor can now be increased by means of key ALT-INC, ordecreased by means of key ALT-DEC, or a new value can be entered directly.

If the selected parameter has write protection, and if the correct password has not yet been en-tered, the user is now requested to enter the password. If the password grants write authorization,the variable can be modified at random.The user returns to the basic menu by pushing key ESC.

8.2.4. Regulator Settings

When selecting the menu item regulator settings, the user accesses a sub-menu that contains thefunctional units of the excitation system.

The next menu item is displayed after the scroll key is pressed.

The different groups of connected functional variables can now be selected for display from thissub-menu.

The displayed variables can now be modified.

V500 Excit. Current+00.8995 _V11 Gen.Vol.Ref.Val+01.0005

Cursor

1 Current Regulat.IF2 Voltage Regulat.UG3 Exc.Cur.IF-Limiter4 Gen.Cur.IG-Limiter

V825 Max.Ref.Val.IF+01.2002V826 Min.Ref.Val.IF+00.0000




8.2.5. Maintenance

By means of this menu item certain excitation system maintenance procedures can be carried out.For example thyristor bridge selection on excitation systems with redundant thyristor rectifierbridges, or the selection of the thyristor cooling fan at systems with redundant fans. Some of thesefunctions may not be applicable for the specific excitation system. Input at a function, which is notinstalled, will not have any result.

8.2.6. Terminal Mode

In this operating mode, all parameters used by the regulator - also those not shown by the othermenu items - can be displayed and modified.

Users can make their own list of parameters, which they wish to have displayed. Entering theirinternal designations, which are found in the regulator diagrams, retrieves these parameters.

When calling up this menu item for the first time, users are requested to enter the first parameter.

Data entry is completed by pressing the ENTER key. The parameter is displayed in the same formas described for menu items 2 and 3.

Further parameters can now be entered, which are put behind the last displayed parameter. Thiscreates the list of the parameters, which are to be displayed.

Parameter Edit:_

Parameter Edit:V100_

V100+01.0002_




Users can scroll up and down the list, as well as enter new parameters, at random. The new en-tries of parameters are put at the end of the list. A list with a maximum of 20 entries can be cre-ated. If more parameters are entered, the oldest entry is removed.

CAUTION

The entered parameters can now be modified, as described. Since this feature allows to changeall regulator parameters, which could constitute a risk for the operating status, the highest level ofwrite authorization is necessary when modifying parameters in this operating mode.

Any subsequent access from the main menu to the menu item ´Terminal Mode´ takes users di-rectly to the output mode, where the parameters of the previously established list are shown.

V100+01.2002 V109_

V100_+01.2002 _V109-00.0005




8.3. Operating Instructions

8.3.1. Preconditions

First, the serial interface connection between GMR3 and the PC has to be made. The DIP switchpositions on module MRB3 have to be selected according to the Settings and Scalings.

8.3.2. Keyboard Functions

ELTERM keyboard:

The above picture shows the keyboard functions of the ELTERM. The eight keys on top are thecommand keys, used for the local commands at the excitation system. They are active all the time,no matter which menu of the ELTERM is selected or which function it is carrying out. Keys for notinstalled functions are omitted.




In dual channel AVRs commands can only be given at the active channel. Commands at thestandby channel (Standby appears on the display) will be ignored. Only the Master key is active.This key is used to select the standby channel to be the active channel, i.e. to change commandfrom the active to the standby channel.

Press the Master key of the standby channel to select the standby channel to take over commandfrom the active channel. On the LCD of the standby channel ‘Standby’ is indicated. (Only applies todual channel regulators).

The lower 16 keys are called menu-keys, which are used for regulator configuration and parameterchanges.

Explanation of command keys:

Commandkey

given at status action

OFF On,Start

Excitation shut down.

ON OFF and Ready Excitation start.AUT/MAN

AUTOAUTO-pfAUTO-Var

Change to Manual (field current) regulation.

AUT/MAN

MAN Change to AUTO (automatic voltage regulation), when no faultis related to voltage sensing circuit and if the generator voltageis within the limits of the voltage regulator setpoint.

p.f./VAR

AUTO Change to power factor regulation (AUTO-pf), if AVR isequipped with an automatic power factor regulator (and notwith an automatic VAR regulator).

p.f./VAR

AUTO Change to VAR regulation, if AVR is equipped with an auto-matic VAR regulator.

p.f./VAR

AUTO No action if AVR is neither equipped with an automatic VARregulator, nor with an automatic power factor regulator.

p.f./VAR

AUTO-VAR Change to AUTO, if AVR is equipped with only an automaticVAR and not with an automatic power factor regulator.

p.f./VAR

AUTO-VAR Change to AUTO-pf, if AVR is equipped with both, automaticVAR regulator and with an automatic power factor regulator.

p.f./VAR

AUTO-pf Change to AUTO.

p.f./VAR

MAN Change to AUTO-VAR respectively AUTO-pf, when no fault isrelated to voltage sensing circuit and if the generator voltage iswithin the limits of the voltage regulator setpoint.

↓ On Setpoint lower.↑ On Setpoint raise.Loc/Rem Loc Change to remote control.Loc/Rem Rem Change to local control.Master Standby and not

Channel Failure!Change of command to standby channel at dual channelregulators.

The above table gives an overview of all possible functions. Some of these functions will not work,if the AVR - plant configuration does not provide these functions. Please check the functions,which are installed in your AVR.




Programming keys:

16 keys are provided for all functions related to changing parameters or carrying out excitationsystem service or AVR-configuration tasks. When the basic screen is shown on the LCD-displaythe ENTER key is used to call up the main menu. By means of the ESC key you can go back tothe previous menu item. Pressing the ESC key also does going back from the main menu to thebasic screen.

The ALT key serves to enter the parameter designators in terminal mode.

The key SCROLL UP, BACKSPACE, ALT INCREMENT serves three functions. The BACKSPACEfunction is available when entering parameter values, or new parameters, in terminal mode; other-wise, the SCROLL UP function is available to scroll through the different menus. If the ALT key ispressed simultaneously, the value of a selected parameter is increased.

8.3.3. Password - Write Protection

Every variable of the GMR3 regulator is assigned a level of write protection. There are altogether 4levels of write protection:

level 0 no write protectionlevel 1 write authorization with password 1level 2 write authorization with password 2level 3 write authorization only in terminal mode with password 2

At the first attempt to modify a variable of levels 1 or 2, users are requested to enter a password. 2passwords are set in the regulator. If the entered password corresponds to the password 2, usersare authorized to modify variables of levels 0 to 2.

If the entered password corresponds to password 1, users are authorized to modify variables oflevels 0 and 1. At any attempt to modify a variable of level 2, the message ‘read only’ appears inthis case.

If the entered password does not correspond to any of the set passwords, users are only author-ized to modify variables of level 0. At any further attempt, i.e. to modify a variable of levels 1 or 2,users will in this case be once more requested to enter the password.

Variables of level 3 can only be modified in Terminal Mode. At any attempt to modify a parameterof level 3 in modes Actual Values or Regulator Settings, the message ‘read only’ appears im-mediately, without any subsequent request to enter the password.

In Terminal Mode, all edited variables have write protection level 3.

Changing the Password:

If the entered password corresponds to password 2, both passwords are displayed immediatelyafter password entry, and the user can change them. If the entered password corresponds topassword 1, password 1 can be changed.

Passwords fall within a range of values between 0 and 65535.

A new password setting must then be copied from the MRB-RAM memory to the EEPROM of theMRB board; otherwise it would be lost during a subsequent system start-up.




Upon delivery of a regulator, both passwords are always set to '0'. At the first attempt to modify thewrite-protected variables of levels 1 or 2, users are requested to enter a password. By entering '0ENTER', both passwords are displayed, and users must now set and store the passwords.

Leading zeros will be ignored, when entering a password!

8.3.4. Parameter Modifications

To modify a parameter that is available in the menu, the value must be selected by moving thecursor to the respective line. The value of the selected parameter can now be increased by meansof the key combination ALT-INC, or decreased by means of the key combination ALT-DEC, orelse, a new value can be entered.

If the selected parameter has write-protection, and if the corresponding password has not yet beenentered, users are requested to enter a password. If entry of the password authorizes users towrite, the variable may be modified as desired. If users have no write authorization, the message‘read only’ appears whenever an attempt is made to modify a variable, or another request ap-pears, i.e. to enter the password.

Direct Parameter Entry:

All analogue variables of the regulator, i.e. the variables designated P, V, X and Y, have a validnumerical range from -16.0000 to +15.9995. The applicable values for the digital variables A, C, Eand I are 0 and 1. Variables with the designation T and in the maintenance menu also variableswith designation V are internal constants of the regulator, with a range from 0 to 65535. All ana-logue variables in the maintenance menu are displayed like T-variables with a range from0...65535.

If a new parameter value is entered directly, it is transmitted to the regulator once the key ENTERhas been pressed to finish the entry. At the same time, it disappears from the display. During en-try, edited characters can be deleted by means of the key SCROLL UP / BACKSPACE. TheESCAPE key removes all entered characters.

If the entered value is beyond the applicable range of values, the regulator sends an error mes-sage, which is displayed on the terminal. The regulator accepts values within an applicable rangeof values. At a subsequent program run on the terminal, the up-to-date value is read out and dis-played. The displayed value represents the entered value with a possible rounding error, due tothe binary notation of the regulator. An internal transfer parameter will be overwritten by the regu-lator program, and cannot be modified.

Parameter Modification by Means of ALT-INC and ALT-DEC:

The selected parameter can be modified directly by means of keys ALT-INC and ALT-DEC. Forthis purpose, the terminal increments or decrements the present parameter value by a certainamount (step) within the limits of the range, as long as the key is actuated. Starting with the small-est step that the regulator can display, i.e. 0.0005 for analogue parameters and 1 for T variables,the step is gradually increased, as long as the key is pressed.

If the selected value does not change when pressing the keys ALT-INC or ALT-DEC, then thevalue is an internal transfer parameter, which the regulator program overwrites immediately.ALT-INC or ALT-DEC cannot change digital variables.




Saving the Settings:

All modifications of parameters, described above, have so far only been stored in the workingmemory of the MRB board and may therefore be lost during a subsequent system start-up.

If the set values are to be stored permanently, they must be copied from the RAM memory of theMRB board into the MRB-EEPROM.

8.4. Error Processing

The GMR3 digital regulating system has integrated functions to check the input and output cards,the main processor board (MRB board) and the sub-processor board (PIM board).

While errors on input or output boards, as well as on the MRB board are displayed on the terminalwithout any user request, the error messages for the PIM board are only shown after calling upmenu item 1 ‘Alarms, Trips’.

8.4.1. Error Processing for MRB Board and IO Hardware

If an error appears on the main processor board (MRB board), or on one of the input or outputboards of the GMR3 regulator, the regulating program of the main processor is stopped.

When connecting the terminal to the regulator, as well as during ongoing operation, the terminalrecognizes automatically that the regulator program was stopped, and the error message‘REGULATOR PROGRAM STOPPED!’ is displayed.

The user terminal now starts the functions, which determine the cause of the error.

IO Error:

If an IO board is not present or defective, the user terminal will display the corresponding errornumber, as well as the position and type of the board. When several boards are defective, the typeand position of the defective board on the left is shown first.

The following types can be displayed:type: E digital input boardtype: A digital output boardtype: X analogue input boardtype: Y analogue output board

Board position:

NGT power supply unitMRB main processor boardreserved if POS15 is free, this position can be equipped with a boardPOS 0 ... POS 15 possible positions for input or output boardsIn full configuration up to a maximum of 16 input and output boards is possible.




MRB Error:

If the regulator program was halted on account of a hardware or software error on the main proc-essor board, the following error messages are possible as a result of the testing functions:

Program Error!SYS-ROM CRC Error!SYS RAM Read-Write Error!No Battery and EEPROM Existing!Program CRC Error!AUX-RAM Read-Write Error!AUX-ROM CRC Error!

CAUTION

Disconnect power supply before exchanging boards!

8.4.2. Operating and Terminal Errors

The following error messages relate only to the terminal itself or its connection to the GMR3 regu-lator unit, as well as to user errors on the terminal.

Communication Errors:

If the GMR3 user terminal cannot establish proper communication with the regulator, it displaysthe error message ‘Communication Error’.

The reasons may be the following, among others:

• A defective connecting line.• A defect on the RS 232 C interface or the GMR3 regulator.• A hardware defect of the terminal.• The GMR3 regulator is not in the run or stop mode. Remedy: Reset regulator!

The above message is triggered when the communication time with the GMR3 regulator is ex-ceeded. It always appears, therefore, when the terminal does either not receive any signals, orreceives signals which it cannot interpret.




User Errors:

The below table is an overview of those error messages that are caused by entry errors on theterminal, such as entering a parameter value under menu item ‘Regulator Settings’ which is toobig.

error message operating mode cause

Illegal Par. Value! Actual ValuesRegulator SettingsMaintenanceTerminal Mode

limits of range exceeded: -16.....+15.9995 for analogue values 0.......65535 for T parameters

Illegal Command! Actual ValuesRegulator SettingsMaintenanceTerminal Mode

Operating error: regulator cannot interpretentered sequence of characters.Or DIP-switch NOQUIT on pcb MRB of GMR3regulator is in position NORM. (Beforechanging parameters DIP-switch NOQUIT hasto be pushed into the left - ON position.

Invalid Parameter! Terminal Mode parameter index too big,parameter type not existing in software




9. REMOTE CONTROL

Following signals are connected to a digital input, which are coming from Speedtronic, DCS orfrom MV Cell. The optional signals coming from DCS must be enabled with an input signal calledB Remote 43R.

9.1. INTERFACE

9.1.1. Digital Inputs

E00 B Excitation Manual MANAVR SRQ DCSRemote field current regulation selection

E01 B Excitation Automatic AUTOAVR SRQ DCSRemote stator voltage regulation selection

E02 B VAR Regulator On QRGLTR SRQ DCSRemote reactive power regulation selection

E03 B p.f. Regulator On PFRGLTR SRQ DCSRemote power factor regulation selection

E05 B Excitation On L41FX SpeedtronicAutomatic closing order

E06 B Excitation Off L83SRX SpeedtronicSpeedtronic field breaker permissive to close

E10 M Unit Circuit Breaker Off UNITBRK POS1 MV CellGenerator circuit breaker position

E11 M Line Circuit Breaker Off LINEBRK POS1 DCSLine circuit breaker position

E16 B Excitation Raise AVRINC CMD DCSExcitation increasing order 83RV Speedtronic

E17 B Excitation Lower AVRDEC CMD DCSExcitation decreasing order 83LV Speedtronic

E19 B Remote 43R L43R SpeedtronicLocal/remote selection

E20 B Turbine Normal Stop L94X1 Speedtronic94X1=1 in case of 32L and 94X1=0 in case of 32R

E23 B Dead Bus Automatic Order L52GCX SpeedtronicDead bus automatic order to close 52G

E28 B Remote Channel Selection AUTOAVR SEL DCSRemote channel selection auto 1 / auto 2

E30 B PSS Off PWRSTABAYS INH DCSInhibition of power system stabilizer




9.1.2. Digital Outputs

A00 M Excitation Manual MANU AVR ON DCSManual feedback position

A01 M Excitation Automatic AUTO AVR ON DCSAutomatic feedback position

A02 M VAR Regulator On QRGLTR ON DCSReactive regulation feedback position

A03 M p.f. Regulator On PFRGLTR SRQ DCSPower factor feedback position

A07 M Local

A08 M Synchronization Automatic L43S AUTO SpeedtronicAuto/manu selection synchronization mode

A16 B Rotor Earth Fault Measuring On ROTOREARTHBRUSH GeneratorActivation of rotor earth fault measuring

A18 M PSS On PWRSTABSYS ON DCSPower system stabilizer is active

A20 M Generator Alarms GENTR ALARM DCSGrouped alarm of GCP

A21 M Excitation Trip Protection

A22 M Speed Raise L70R4CSR SpeedtronicTurbine sped set point raise

A23 M speed Lower L70R4CSL SpeedtronicTurbine speed set point lower

A29 B Rotor Earth Fault Brush On ROTOREARTHBRUSHCTRL

Speedtronic

9.2. OPERATING MODES

9.2.1. Voltage Regulator (Automatic Mode)

For shunt field excitation systems the initial excitation is switched on with the beginning of the ex-citation sequence and deactivated when a minimum thyristor voltage is reached.

In this operating mode the generator voltage is regulated to the adjusted set value. The settingrange for the set value is adjusted to the permissible limits of the generator and can be viewed andchanged with the User terminal in the menu Regulator Settings as "Max. Reference Value UG" or"Min. Reference Value UG" (refer to the document for settings and scalings).

The regulator is locally brought to this operating mode with the AUTO/MANUAL key.

When the ON command is given an internal automatic sequence is executed which is first closingthe field breaker. When all commands are accomplished an all feedback signals available then the"EXCITATION ON" indication is set and displayed locally and also the "M Excitation On" outputactivated. After completing the start-up sequence the machine is always regulating to the set "StartReference Value UG".After the ON indication the voltage can be controlled either from remote or locally with the éêkeys. Thus in on-load operation the voltage and therefore also the reactive power is regulated.




9.2.2. Field Current Regulator (Manual Control)

This operating mode is applied for test purposes as well as case of actual value loss of the voltageregulator. During on-load operation in this mode the generator values have to be permanentlychecked and when necessary in case of power system fluctuations or generator load changes thegenerator voltage respectively the reactive power controlled accordingly. Further, no limiters areactive and also the additional regulator cannot be selected and activated.

The regulator is pre-selected for this operating mode via the AUTO/MANUAL key. After start-upthe current regulator is regulating to the starting set value "Start Reference Value IF", the genera-tor is excited to a value corresponding to this field current and can be brought from there on tonominal voltage with the é key.

When the excitation is changed to external excitation with the manually operated links (i.e. supplyfor the power circuit is available) then the starting set value is equal to the negative limit of the fieldcurrent regulator, which is less then 0 to have a secure condition after starting of the excitation inmanual mode.

The control sequence and the start conditions are analogous to the automatic mode of operation.The setting range for the set value can be viewed and modified under option "Max. ReferenceValue IF" and " Min. Reference Value IF".

9.2.3. Power factor / Reactive Power Regulation

In addition to the voltage regulation feature also two higher level regulators are available (optionalpower factor- or reactive power regulator) in the automatic channel which are acting onto the setvalue of the voltage regulator. This way the regulating range of voltage regulator can never ex-ceeded or fall below the limit.

This regulator can be selected locally via the "p.f. / VAR" key or by the digital input.In any case activation and de-activation will be performed smoothly. There are following possibili-ties:

• Activation of the additional regulator:The excitation system must be in operation and the regulator in automatic mode. An high sig-nal to the digital input will activate the respective regulator.

• De-activation of the additional regulator:When de-activating the additional regulator (switchover to voltage regulator) the setpoint is leftunchanged on its present value.

NOTE

This additional regulator cannot operate in isolated operation but only when the generator is con-nected to the grid. In dependence of the position of generator and line circuit breaker this regulatoris blocked and the voltage regulator is active. The additional regulator starts acting only at closedcircuit breaker.




Power factor regulator: The power factor is regulated to the value "Start Reference ValueTAN".

When the regulator is activated then the setpoint of this regulator canbe changed from remote or locally via the é ê keys.

The setting range of the setpoint can be checked and modified under"Max. Reference Value TAN" or "Min. Reference Value TAN". All val-ues are entered as tanϕ values, e.g. the value 1 corresponds to a loadangle ϕ of 45 ° which is equivalent to a power factor of 0.71.

Reactive power regulator: The reactive power is regulated to the value "Start Reference Value Q”When the regulator is activated the setpoint of this regulator can bechanged from remote or locally via the é ê keys.

The setting range of the setpoint can be checked and modified under"Max. Reference Value Q" or "Min. Reference Value Q".

In isolated operation the regulator has to be switched off in any case, which is identified by theposition of the circuit breakers.

9.2.4. Change Over Between the Automatic and Manual and Power factor / Reac-tive Power Regulation Mode

The operating modes can be changed locally:

• During operation whereby an automatic follow-up feature will ensure matching between theactive and not active channel whereby at any time a smooth transfer is taking place.

• By failure of the automatic operating mode an automatic change over to manual mode is per-formed. This transfer is initiated upon loss of the generator voltage actual value. A transferfrom manual- to automatic mode can be performed locally or with a remote signal.

• When the "AUTO" mode is pre-selected the additional regulator can be selected locally via the"p.f. / VAR" keys. The optional additional regulator must be activated in regulator software andthis is done if the reactive load regulator are provided.

• In case the power factor- or reactive power regulator is active and it is transferred to"MANUAL" then the previous operating mode is not stored and when it is changed back to"AUTO" the power factor- or reactive power regulator has to be activated again.

• If the regulator is in manual mode during the switching on of the generator circuit breaker theregulator makes an automatically change over to the automatic mode.

When during operation the operating mode is transferred to manual then it will also remain in thisstate during shut down, standstill and re-start as long as the AUTO/MANUAL key of the excitationis operated.

Note: In case a transfer from manual- to automatic operating mode is blocked then possiblythe generator voltage is outside the automatic regulating range.




9.3. DE-EXCITATION

De-excitation can be performed during normal operation or due to a protection trip. The"EXCITATION OFF" command can be given from remote or locally.

During an operational shut down first of all the thyristor will internally change into converter opera-tion. Thus the energy stored in the field is dissipated and the field breaker opened with a time de-lay and therefore for it's main contacts under no-load conditions.

During an external protection trip as well as an internal forced shut down the de-excitation contac-tor is directly and immediately operated and a follow-up of the control circuits is carried out.




10. MAINTENANCE AND TROUBLE SHOOTING

10.1. ALARM ANNUNCIATION

10.1.1. General and Accepting/resetting

CAUTION

Opening the GCP cubicle and working in the excitation system under voltage is dangerous andtherefore strictly prohibited until all supplies have been switched off.

The more important components which are catering for correct operation and provisions for safetyare partly supervised by electrical contacts or monitored via the software.

Each abnormal condition in the excitation system is indicated on the LC display and depending onit's cause and importance will produce an alarm annunciation, a trip or a transfer of operatingmode. A common external annunciation for alarm and trip is included in the system.

The alarm menu is accessed by either pressing MENU/ENTER or by operating any of the numberkeys.

Each alarm annunciation is displayed by a text line, yet a fault can also initiate several annuncia-tions thus providing additional information of the occurring fault condition (e.g. "voltage actualvalue failure" and "mcb trip alarm").

A flashing * asterisk on the left of the annunciation indicates an alarm status which can only bereset once the fault has disappeared. It could also happen that a fault is cancelled by a shutdownand reoccurs when starting up again (e.g. a missing actual value, an excessive operating se-quence runtime, etc.).

The order of the annunciation corresponds to the time sequence of the faults occurring and is in-dependent from the alarm being either steady-on or gone. The uppermost line represents the mostrecent alarm.

Example:

Last (most recent) alarm

Flashing asterisk: steady-on alarm

By operating the scroll down key the earlier alarms occurredare displayed.

It is recommended that at each fault displayed to refer to the following fault check list, to find andrectify the cause to exchange a possibly faulty component.

Have all LED's on the MRB3 module gone out then the power supply has failed and also the Useroperating unit cannot provide information anymore. In this case the watchdog facility will trip thefield breaker and initiate an external alarm.

start overtime trip thyr. current fail ∗thyristor fuse fail ∗m.c.b. tripped




10.1.2. List of Possible Alarm Annunciation

901 Start overtime trip 929 Gate pulse fail902 Stop overtime trip 930 Pulse relay fault903 Voltage sensing fail 932 Error 32 = Excitation overcurrent trip904 Field breaker fail 934 Excitation transformer temp. warning905 Field flashing fail 935 Excitation transformer temp. trip906 AC supply fail 937 HV fuse fail907 DC supply fail 944 Generator short circuited909 Stand-by channel fail 947 Error 47 = Current boosting trip912 mcb tripped 948 Error 48 = Touch-Panel comm. fail913 AC overvoltage protection fail 949 Invalid parameter914 Speed < trip 520 PIM0 manual gate control916 Excitation overcurrent alarm 522 PIM0-A synchronization fail918 Rotating diode fail 521 PIM0-A program stop919 Thyristor voltage fail 523 PIM0-B program stop920 Thyristor current fail 524 PIM0-C program stop923 Thyristor fuse trip 525 PIM0 communication error928 Thyristor temperature trip 526 PIM0 processor A,B fail

527 PIM0 processor C fail

10.1.3. Detailed Specification

901 Start overtime trip Result: TripSupervised: Runtime supervision (internal software logic).Cause: Excessive starting time during start-up se-

quence;Initial excitation voltage missing;Malfunctioning of a relay or contactor;Malfunction of module DE inputs or DA outputs;Malfunction of de-excitation contactor;Missing feedback signal.

Measures: Check all voltage supplies;Check inputs and outputs of interface relays;Check contactors and feedback signals.

902 Stop overtime trip Result: TripSupervised: Runtime supervision (internal software logic).Cause: Excessive starting time during shut down se-

quence;Malfunctioning of a relay or contactor;Malfunction of module DE inputs or DA outputsMissing feedback signal.

Measures: Check all voltage supplies;Check inputs and outputs of interface relays;Check contactors and feedback signals.




903 Voltage sensing fail Result: Transfer to MANUAL when AUTO mode;Alarm when in MANUAL mode;Channel change-over in case of dual channelregulator.

Supervised: Internal software logic;Cause: Loss of PT voltage during operation;

PT mcb trip;Generator PT or interposing PT fault;Disruption of actual value circuit.

Measures: Check PT and PT-wiring; switch on PT mcb;slowly raise voltage in manual mode and meas-ure generator voltage(also internal variable UGKV501);Change back to AUTO mode.

904 Field breaker fail Result: TripSupervised: Position indication circuit of field breaker;

Additional information to runtime supervision.Cause: Fault in the field breaker ON control circuit;

Malfunction of field breaker;Start overtime or stop overtime time trip;Field breaker switched off during operation;Fault in position indication circuit;Missing feedback signal.

Measures: Check all voltage supplies;Check field breaker and ON circuit;Test trip circuits.

905 Field flashing fail Result: TripSupervised: Position indication circuit of field breaker;

Additional information to runtime supervision.Cause: Fault in the field flashing contactor ON control

circuit;Malfunction of contactor;Start overtime trip;Field breaker switched off during start sequence;Fault in position indication circuit;Missing feedback signal.

Measures: Check all voltage supplies;Check contactor and ON circuit; Test trip circuits.




906 AC supply fail Result: Alarm dual channel regulator;Trip single channel regulator.

Supervised: Internal software logic or thyristor fuses or mcb-F09 trip.

Cause: Gate control set cannot synchronize impulses;Lack of thyristor voltage during operation;Thyristor fuses trip;Regulator mcb -F09 (-F19 dual channel regula-tor) trip (regulator supply);Excitation transformer HV fuse blown;Short circuit or overload of excitation supply cir-cuits.

Measures: Switch on mcb or replace fuse;Check excitation transformer or regulator trans-former;Check thyristor fuse;Check power supply cables.

909 Stand-by channel fail Result: AlarmSupervised: Internal software logic.Cause: Change-over to stand-by channel is not allowed.Measures Check the stand-by channel according its fail-

ures.912 mcb tripped Result: Alarm

Supervised: Auxiliary contacts of mcb’s .Cause: Short circuit;

Overload.Measures: Switch on the mcb’s;

Check the respective current.914 Speed < trip Result: Trip

Supervised: Internal software logic – frequency supervision.Cause: Speed drops below 90 % of nominal speed.Measures: Raise generator speed.

916 Excitation overcurrentalarm

Result: AlarmSupervised: Overcurrent protection relay.Cause: Overcurrent in field circuit.Measures: Check the field circuit;

Check the actual value of field current.918 Rotating diode fail Result: Trip

Supervised: Software monitoring (evaluation of field currenthigher harmonics).

Cause: Short- or open circuit of rotating diode.Measures: Check flywheel diodes rectifier in rotor circuit;

Replace defective parts.Note: When fault occurs during normal operation with-

out any diode fault then the trigger value for di-ode failure supervision has to be increased.




919 Thyristor voltage fail Result: TripSupervised: Internal software logic – additional information to

runtime supervision.Cause: Start-up overtime;

After starting AC thyristor voltage is not estab-lished;Thyristor fuse blown;Station supply too low or not available (at testsupply);Initial excitation voltage too low or not available.

Measures: Measure station supply voltage;Check supply fuses;Check thyristor fuses;Check initial excitation circuit;Check matching transformer;Check power supply cable.

920 Thyristor current fail Result: TripSupervised: Internal software logic - additional information to

run-time supervision.Cause: Start-up overtime;

After starting thyristor current is not established;Thyristor fuse blown;Initial excitation voltage too low or not available.

Measures: Check initial excitation voltage and supply fuses;Check thyristor fuses;Check initial excitation circuit;Check matching transformer;Check power supply cable.

923 Thyristor fuse trip Result: Alarm dual channel regulator;Trip single channel regulator.

Supervised: Micro switches mounted on the fuses of the thy-ristor bridge.

Cause: Short circuit on;Defective thyristor;Defective AC overvoltage protection circuit;Excessive overload due to fault.

Measures: Check thyristors;Check AC overvoltage protection circuit;Replace the defective fuse(s).

928 Thyristor temperature trip Result: AlarmSupervised: Thermo switch mounted on the heat sink of thy-

ristor bridge.Cause: Overload;

Insufficient cooling due to pollution;Defective fan or circuit.

Measures: Clean air inlet and outlet and heat sink;Wait for the cooling of the rectifier;Check fan and circuit.




929 Gate pulse failure Result: Trip single channel regulator;Alarm dual channel regulator.

Supervised: Internal software logic.Cause: Thyristor current less then 0.1 p.u., caused by

missing or incorrect firing pulses;Fault in a pulse cable;Gate pulse transducer board LG6;Gate pulse output board SAB;Change over board ZUP (cold stand-by rectifier).

Measures: Check firing pulses on all p.c.b.’s;Check the wiring of the firing pulses to the thy-ristors.

930 Pulse relay fault Result: Trip single channel regulator;Alarm dual channel regulator.

Supervised: Internal software logic.Cause: Defective gate pulse blocking relay;

Wiring fault.Measures: Check the relay on board SAB;

Check the wiring and voltages to board IWK.932 Error 32

Excitation overcurrent tripResult: TripSupervised: Overcurrent protection relay.Cause: Field current regulator failure.Measures: Check the actual value of field current;

Check the circuit for the actual value of field cur-rent;Check the overprotection relay.

934 Excitation transformer tem-perature warning

Result: AlarmSupervised: Signal to the regulator coming from transformer

temperature detection.Cause: Overload;

Insufficient cooling.Measures: Decrease reactive load;

Wait cooling, clean air inlets.935 Excitation transformer tem-

perature tripResult: TripSupervised: Signal to the regulator coming from transformer

temperature detection.Cause: Overload;

Insufficient cooling.Measures: Decrease reactive load;

Wait cooling, clean air inlets.937 HV fuse fail Result: Alarm

Supervised: Signal to the regulator coming from HV fuses.Cause:Measures:




944 Generator short circuited Result: TripSupervised: Internal software logic.Cause: Stator current rising during initial excitation;

Generator terminals are short circuited.Measures: Check generator busbar.

947 Error 47Current boosting trip

Result: TripSupervised: Internal software logic.Cause: Defective current boosting circuit;

Defective contactor;Measures: Check the current boosting circuit;

Check the contactor.948 Error 48

Touch Panel Communica-tion fail

Result: AlarmSupervised: Internal software logic.Cause: Defective modbus communication board COM4;

Defective Touch PanelBad connection of the modbus link.

Measures: Check the communication card;Check Touch Panel;Check the modbus link.

949 Invalid parameter Result: TripSupervised: Software monitoring.Cause: No valid parameter set in EEPROM processors.Measures: Load and save BIN-file or change MRB3 module.

520 PIM0 manual gate control Result: AlarmSupervised: Internal software logic.Cause: Switch HST on SAB module set to 1. Gate con-

trol is switched to manual operation, regulator isdisabled!

Measures: After finalizing tests change switch back again.522 PIM0-A synchronization fail Result: Trip

Supervised: Software monitoring;Cause: Grid regulator unable to synchronize impulses.Measures: Check and measure voltages on regulator sup-

plytransformer T05;Check plug-in connector SAB-IWK.

521 PIM0-A program stop523 PIM0-B program stop524 PIM0-C program stop525 PIM0 communication error526 PIM0 processor A,B fail527 PIM0 processor C fail

Result: Alarm or trip, depending on type of failureSupervised: Internal software logicCause: Defective circuit on board PIM, or communication

with the main processor board MRB3 failed.Measures: Replace board PIM.

NO LOCAL ANNUNCIATION,HOWEVER A PERMANENTTRIP

Result: Trip; external annunciationSupervised: Regulator watchdog.Cause: Regulating supply failure; Microprocessor

stopped, therefore no alarm indication.Measures: Check regulator supply




10.2. FAULTFINDING

SYMPTOMS POSSIBLE CAUSE SOLUTION

Generator voltage notbeing established

Voltage supply for initial excita-tion not connected

Connect voltage supply for initialexcitation to the terminalsFLASH/BOOSTPWRSPLY

Regulator selected to "MANUAL"operating mode

Change regulator to "AUTO"mode

Field breaker is in open position Check control circuits

No voltage on terminalsEXCITPWRSPLY

Check fuses, wiring and rating ofpower transformers

No connection between excitationsystem and field of exciter ma-chine

Check wiring

Thyristor fuses not inserted orblown

Check nominal value and insertfuse

Generator voltageonly 2...3 % of UGN

Exciter machine or rotating diodewheel faulty, open circuit in rotor

Shut down unit and measure di-odes of exciter machine

Regulator selected to "MANUAL"operating mode

Change regulator mode to"AUTO"





Terminal voltage isrising to approx. 80 %UGN and falls backagain

After initial excitation the thyris-tors do not take over the fieldcurrent because of:

Thyristors faulty Check thyristors:G-C circuit:R=5...100RC-A circuit: R>100K (+) and (-)

Thyristor fuses not inserted ordefect

Check fuse rating and insertfuses

No firing impulse on thyristors Regulator board SAB does notproduce impulses, therefore re-place board

Terminal voltage toohigh and uncontrolla-ble

No actual value on terminalsX11:02, 03, 04

Check wiring

Actual value mcb open position Close actual value mcb

Actual value circuit connected towrong voltage

Check PT rating and wiring

Voltage set value not calibratedcorrectly

Re-calibrate voltage set valueproperly (NormUg V813)

Thyristors faulty, continuous firing Check thyristors

Terminal voltage isnot exactly rising tonominal voltage

Parameter for start-up set valueincorrectly adjusted

Set parameter for start-up setvalue SWAU V827 to 1,0

Terminal voltage toohigh or too low butcontrollable

Actual value circuit connected towrong voltage

Check PT rating and wiring

Voltage set value calibrated notcorrectly

Adjust voltage set value properly(NormUg V813)

Regulator selected to "MANUAL"mode

Change regulator to "AUTO"mode of operation





Inaccurate or slowregulation

According to the machine datarequired excitation voltage at fullload is larger than the maximumexcitation system output voltage;Field section connected in series

Check design and/or contact VATECH SAT / dept. PE

Regulator not optimised Optimise regulator

Fault in generator, excitation ma-chine or the rotating diode wheel,increased field current

Shut down unit and check di-odes; replace if necessary

Reactive power static (BSTATV831) not in 0 position (only rec-ognised in isolated operation, isall right for system on-load op-eration)

Does not represent a fault sincefor stability when operating inparallel to the grid a reactivestatic is required (either naturaltransformer static and or static ofvoltage regulator). Accuracy canbe enhanced by varying staticinto 0 direction (caution! A ma-chine with a too low static will beunstable in on-load operation).

Generator unit not on nominalspeed

Adjust to nominal speed

Thyristor fault in power circuit Measure thyristors as outlinedbefore

Terminal voltage ex-cessive overshootduring start-up

Soft-Start parameter not properlyadjusted

Set parameter for Soft-Startproperly

Terminal voltage os-cillates

Frequency unstable Optimize turbine regulator, faultnot within excitation system





Terminal voltage os-cillates (continued)

System voltage oscillation due toloading or unloading high con-sumers

Represents no fault since theconsumers are causing voltagedips or raise when connected ordisconnected which only cansubsequently be compensated bythe voltage regulator. Oscillationscan possibly be reduced by rais-ing the reactive static from 0 fur-ther to negative direction (BSTATV831) or varyingVPU V872

Intermittent fault in generator, inexciter machine or in diode wheel

Shut down unit and check diodesof the exciter machine

When connected inparallel to the gridsystem no reactiveload static can beattained (reactive cur-rent is running off) orthe voltage regulatoris responding too vio-lently on small systemchanges or when op-erating in parallel withother units the reac-tive power distributionis oscillating

Reactive power static (BSTATV831) set too low or to 0

Static CT or PT actual value notconnected to the correct phasesor wrong polarity

Increase reactive power staticfrom 0 into negative direction(BSTAT V831)Check wiring and correct if nec-essary. With single phase meas-uring the CT has to be located inthe phase which is not used forvoltage measuring

Static CT polarity not correctlyconnected or even still short cir-cuited

Check wiring and CT terminalstripsCheck an calibrate active- andreactive power to a value andpolarity





Reactive power shar-ing not equal but sta-ble

Reactive power static (BSTATV831) not equally set on unitsoperating in parallel

Check setting and equally adjustreactive power static(BSTAT V831)

Unable to control theexcitation system

System is selected to "REMOTE" Change operating mode to"LOCAL"

Some control func-tions cannot be exe-cuted

Some inputs or outputs faulty Replace the boards DE32 orDA32

User terminal defect Replace User terminal

Diode failure supervi-sion is activated dur-ing normal systemoperation

Fault in rotating diode wheel Shut down unit and check diodesof excitation machine

If diodes are in order: Increase trip setting (V1003)

10.3. FAULTY PRINTED CIRCUIT CARDS

When the digital system is running, on the board MRB3 following LED's must be active:

RUN, HWOK, POWER

If one of the LED's is not active, then each of the cards can be the reason for this. By change ofthe individual cards the defective card can be fixed.

If spare cards are delivered, then these spare cards are identical with the cards in operation. Thatmeans, they have installed the same software, parameters and jumpers. Nevertheless beforechanging a card an optical check should be performed:

• Is there a visual mechanical of electrical damage?• Do all jumpers match with the original card?• Do all switch positions (f.e. DIP switches) match with the original card?• Can you conclude from different EPROM labels to different program versions?• Do the IC equipment match with the original card (especially EPROM's)?

Each pcb is fixed by screws on the front plate (top and bottom screws). To pull out and to plug in acard the voltage supply must be switched off (the best is to switch off the DC voltage supply of theregulator GMR3).

CAUTION

Switching off the mcb -F01 results in every case in a trip of the excitation!

After change of the card and restoration of the operation conditions (fix all plugs and screws) thevoltage can be switched on again by operation the mcb.




If all card are ready, then after switching on the voltage supply the LED "POWER" on the MRB3card must be active. After an initialization time of the MRB3 card of approx. 8 sec. the LED's RUNand HWOK must become active. Then the GMR3 and so the excitation system is ready for opera-tion again. The user terminal needs (approx.) 8 sec. more for readiness of indication and com-mands.

If not so, then the replaced card was not the reason for the failure and faultfinding respondingchanging of cards must be continued.

After replacement of a card we recommend to perform a complete start/stop procedure of the ex-citation until reaching nominal voltage of the generator. During this sequences the function of theexcitation shall be observed.

10.4. PERIODIC MAINTENANCE

With the exception of relays, contactors and ventilator there are no other moving parts in the exci-tation and therefore the system can be referred to as being almost maintenance-free. The equip-ment should be cleaned at regular intervals, the terminal connection checked and tightened if nec-essary.

It is recommended that a periodic inspection of the field breaker, the initial excitation, the currentboosting and the ventilator is carried out approximately once a year.

11. INSTALLATION

CAUTION

1) Insulation- and high voltage tests can internally be done only by the power circuits. Improperapplication can severely damage semiconductors or solid state modules of the excitation sys-tem!

2) Assembling of the excitation system must be carried out very careful with due consideration ofthe technical data of the synchronous generator and the CT's and PT's. Even short operationwith incorrect connections may destroy the excitation equipment.

The rectifier of the excitation system is forced cooled, other devices are naturally cooled andshould not be mounted in the vicinity of heat producing equipment or installed in such enclosedplaces where the ambient temperature is exceeding the maximum permissible operational tem-perature.




12. PRE-SETTINGS FOR COMMISSIONING

12.1. SWITCHES ON MRB3 MODULE

The DIP switches on the front plate of the MRB3 module have always to following positions (forparameter setting as well as for operation). Merely for loading a modified parameter into theEEPROM the parameter I419 should be set high, during the updating of EEPROM the UPD-LEDblinks shortly.

OUT EN 1 n outputs activeAUTRES 2 n auto reset activeAUTSTA 3 n N auto start activeNOQUIT 4 n O program stop enabledBATT 5 n R battery supervision lockedHW EN 6 n M hardware activeAP ROM 7 n after reset EEPROM -> user programROM PR 8 n write protected

12.2. LIST OF THE CONFIGURATION PARAMETERS

The parameters listed in Settings and Scalings are required for configuration and have to be veri-fied and if necessary corrected before commissioning.

Testing and setting is carried out via the User terminal in terminal operation mode.

NOTE

After parameter modification these data have to be stored in EEPOROM.

12.3. CALIBRATION OF LC-DISPLAY

In order that the measured value shown on the LC display correspond with the actual physicalranges have to be calibrated. Calibration is carried out in a way that the entered value according tothe instructions below is corresponding to the 1 p.u. value of the variable.

The representation of the calibration parameter is based on a diminished floating point formatwhereby the last digit of the parameter is interpreted as exponent and the first four as mantissa.

The corresponding variable is computed with the computing format, a 5-digit integer number. Forthe input into the User terminal it has to be converted to the entry format (decimal point in format+00.0000).

Format: XXXXE

e.g.: V1005 = 01006 (computing format): 100*10E6 = 100 MWV1005 = 00103 (computing format): 10*10E3 = 10 kV

Largest value of mantissa: 6553Largest value of exponent: 6 (above values are not considered).

Mantissa

Exponent




Following calibration parameters and actual values are used:

Actualvalue

Calibration parameter

Generator voltage V501 V1007Generator current V503 V1006Active power V574 V1005Reactive power V65 V1005Field current V500 V1004

Converting the computing format (CF) into entry format (EF):

0 ≤ V (CF) ≤ 32767: V (EF) = V (CF) / 2048 (V with positive sign)32768 ≤ V (CF) ≤ 65535: V (EF) = V (CF) / 2048 - 32 (V with negative sign)

Example: V (RF) = 1006 ⇒ V (EF) = 0.4912V (RF) = 40004 ⇒ V (EF) = -12.4668

Note: After the decimal point there must be 4 digits whereby the last digit is rounded (from 0,i.e. with negative integers rounded to negative: -12.46679 ⇒ -12.4668)

Output Format:

The terminal is operating with 2 output formats, which are specified in the terminal text file.

Format 1: 4 digits, including decimal point: only negative sign is issued.Format 2: 4 digits, including decimal point: correct sign is always issued.

The choice of the exponents influences the number of digits after the decimal point. The numberof digits before the decimal point is fixed. There are always 4 digits produced including zeroes be-fore the point. In case of an overflow the output will exceed 4 digits.

Entering kVA Ratings:

Machine nominal rating V1005 (CF) Output format<2 kVA XXXX0 +yyyy VA2...20 kVA XXXX1 +yy.yy kVA20...80 kVA XXXX2 +yyy.y kVA80 kVA...2 MVA XXXX3 +yyyy kVA2...20 MVA XXXX4 +yy.yy MVA20...80 MVA XXXX5 +yyy.y MVA80...6553 MVA XXXX6 +yyy MVA

Example: Snom=40 MVA: V1005 (RF) = 40004 Output at Pnom: +40.00 MWV1005 (RF) = 04005 Output at Pnom: +040.0 MWV1005 (RF) = 00406 Output at Pnom: +040 MW

Example: Snom=100 VA: V1005 (RF) = 01000 Output at Pnom: 100 WV1005 (EF) = 0.4883




Entering Voltages:

Machine nominal votage V1007 (RF) Output format<6553 V XXXX0 Yyyy V<8 kV XXXX1 (y)y.yy kV>8 kV XXXX2 yy.y kV

Example: Vnom =8 kV: V1007 (RF) = 08001 Output at Vnom: 8.00 kVV1007 (RF) = 00802 Output at Vnom: 08.0 kV

Example: Vnom=100 V: V1007 (RF) = 01000 Output at Vnom: 100 VV1007 (EF) = 0.4883

Entering Currents:

Stator-/ Field nominal current V1004, V1006(RF)

Output format

I ≤ 10 A XXX8 y.yy AI ≤ 25 A XXX9 yy.y AI ≤ 300 A XXXX0 (y)yyy A (I > 50 A)

(y)yy.y A (I < 50 A)I >300 A XXXX0 Yyyy AI >1000 A XXXX1 y.yy kA

Example: Inom=1000 A: V1006 (RF) = 01001 Output at Inom: 1.00 kAV1006 (RF) = 10000 Output at Inom: 1000 AV1006 (RF) = 10000 Output at Inom: 1000 A

Example: Inom=25 A: V1004 (RF) = 00250 Output at Inom: 25.0 AV1004 (EF) = 0.1221

Inom=13,5 A: V1004 (RF) = 01359 Output at Inom: 13.5 AV1004 (EF) = 0. 6636

Inom=8,5 A: V1004 (RF) = 08508 Output at Inom: 8.5 AV1004 (EF) = 4.1543

Note: For currents < 50 A a digit after the decimal point is produced.(y)..... 'Overflow', can also be applied intentionally.For values >1000 A optionally XXXX1 or XXXX0 can be used.




13. COMMISSIONING

13.1. PREPARATION FOR COMMISSIONING

Before commissioning it has to be checked whether the ordered and delivered excitation systemparameters are identical to plant requirements – especially the voltage range.

CAUTION

Following items have strictly to be verified to ensure perfect operation of the excitation system:

1) Check design and external components2) Correct installation of all components3) All mcb's switched OFF4) Check interface to plant, station control and protection5) CT/PT wiring check6) All voltage circuits to be checked7) Preliminary setting of all configuration parameters8) Preliminary setting calibration values for LC displayNote: For items 7) and 8) the GMR3 has to be energized.

13.2. MEASURING POINTS

During the commissioning most important regulator internal variables should be displayed on os-cilloscope, for this the transformation of the internal variables are made by the analogues outputboard AA8. If analogues output board is not implemented in GMR3, the commissioning personalshould insert this board for the duration of the commissioning.Following signals are available on the AA8 for test purposes.

Designation Name Variable Calibration⊥ Common GroundY3 DEIW

Calculated value of load angleV38 1 V = 20°el.

Y7 UGKActual value of stator voltage

V501 5 V = 100% UGN

Y6 UGSW-UGKDifference between set and actualvalue of stator voltage

V79 10 V = 100% UGN

Y2 IPIWActual value of field current

V500 5 V = IFN

Y5 ALPHIWActual value of firing angle

V509 1 V = 20° el.

Tolerance for all 3 measuring signals: ±10 %




13.3. CONSIDERATIONS

13.3.1. Calibration Principle

Within the regulator several calibrations have to be performed in order that the regulating quanti-ties correspond with the actual values of the plant equipment. For example: so that the generatorcurrent actual value (IGIW) is really equal to 1 p.u. (100 %) in the regulator at an actual 100 %generator current flow. The calibration sequence should be applied according to this protocol inorder that by adjusting the calibration setting value there is no influence on the momentarily regu-lation. For example the IGIW calibration should be carried out at rated generator current which ispossible during primary short circuit tests where the excitation is in field current regulating modeand the generator current does not represent any regulating quantity in that operating mode.

For calibration the terminal mode has to be selected on the User terminal. After calibration the newparameter setting have to be stored permanently.

The calibration values of the excitation system are pre-set according to the generator data duringthe workshop test, but these parameters should be checked with the actual technical data of thegenerator.

The following values have to calibrated or the calibration must be checked according to the gen-erator data.• Thyristor voltage• Field current• Generator stator current• Generator terminal voltage

Calibration of thyristor voltage (=supply voltage):

1.) Set V803 to 12.) Read V537 and substitute it in the following formula3.) Measure the incoming supply voltage4.) Calculation:

USynNUSyn

V371V803 ∗=

V803.........…. Calibration factor for the thyristor voltage NormUsynUSyn.............. Incoming supply voltageUSynN……….. Nominal supply voltage

5.) Enter the calculated value of the variable V8036.) Afterwards the variable should be: USYNIW V37 = 1,0




Calibration of the field current:

1.) Set V805 to 12.) Read V500 and substitute it in the following formula3.) Measure the field current (on shunt 150 A / 150 mV)4.) Calculation:

FNIFI

V5001V805 ∗=

V805..........… Calibration factor for the field current NormIfIF..............…. Actual value of the current, measured on ShuntIFN.............… Nominal field current

5.) Enter the calculated value of the variable V8056.) Afterwards the variable should be at nominal current: IPIW V500 = 1,0

Calibration of the generator stator current:

1.) Set V817 to 12.) Read V503 and substitute it in the following formula3.) Measure the generator stator current (secondary side of the CT)4.) Calculation:

GNIGI

V5031V817 ∗=

V817..........… Calibration factor for generator stator current NormIgIG..............…. Actual value of the current, measured at the CTIGN.............… CT secondary current at generator nominal current

7.) Enter the calculated value of the variable V8178.) Afterwards the variable should be at nominal current: IGIW V503 = 1,0

Calibration of the generator terminal voltage:

1.) Set V813 to 12.) Read V501 and substitute it in the following formula3.) Measure the generator terminal voltage (secondary side of the PT)4.) Calculation:

GNUGU

V5011V813 ∗=

V813.........…. Calibration factor for generator voltage NormUgUG.................. Actual value of the voltage, measured at the PTUGN................ PT secondary voltage at generator nominal voltage

5.) Enter the calculated value of the variable V8136.) Afterwards the variable should be at nominal voltage: UGK V501 = 1,0




13.3.2. Principle for Optimizing the Regulator

The purpose of optimization is that the regulating value (field current or generator voltage) is re-acting as rapidly as possible to sudden changes without oscillation (to be recognized on the firingangle α). Therefore the firing angle α has to be displayed on oscilloscope.

Procedures:1. First of all optimize the regulator with small step signals (step functions with 3 - 5 %)2. only then later with large jumps (step functions with 10 %)3. and then excitation raising from zero

At optimizing with small value signals always optimize from the inner loop to the outer loop, thatmeans:1. Field current regulator (PI)2. Voltage regulator (PID)3. Limiters and additional regulator (reactive power or p.f. regulator)

ad 1) + 2) Field current regulator and Voltage regulator

Optimizing is carried out by increasing the P-gain until the respective regulator starts oscillation(firing angle α). Then decrease the gain slightly again until oscillation stops. Afterwards adjust theintegration time with step functions (in that way, that actual value reaches the new setpoint withsmall or without overshooting). At excitation systems with exciter machines optimize the differentialpart (D-part) with the same procedure (increase the D-gain until overshooting at step functions oruntil oscillation of the firing angle α, afterwards adjust the differential damping).

When during on-load operation the control voltage is starting to oscillate then the P-gain has still tobe reduced.

NOTE

General statement: At a high gain the regulator tends to oscillate, but has a fast regulation. A lowgain increases the stability, but results in poor regulation

Note: Generally pre-setting of the D-part is sufficient without any further modifications.

ad 3) p.f. and reactive power regulator

At the p.f. and reactive power regulator the regulation part with the gain is integrated in the feed-back. Therefore the considerations regarding the stability and oscillation is exactly reverse. Thatmeans, a low gain results in high oscillation tendency, at a higher gain the regulator tends to sta-bility. Generally the presetting can be left unchanged.




13.3.3. Recommended Settings

Normally with the settings from the workshop test the excitation system can be operated without orwith slightly parameter changes. If nevertheless parameters have to be changes due to poorregulation (oscillation, to much overshooting, slow regulation) we recommend the following ranges:

Recommendation for the field current regulator:

V870 VPI Gain field current regulator 2.00 ... 5.00V900 TNI Integration time field current regulator 0.0

Recommendation for the voltage regulator:

V872 VPU Gain voltage regulator 5.00 ... 8.00V902 TNU Integration time voltage regulator 0.20 ... 0.70 = 0.2 ... 0.7 sV871 KDU Differential gain voltage regulator 0.50 ... 1.00V901 TDU Differential damping voltage regulator 0.005.. 0.02 = 0.5 ... 2 ms

Recommendation for the p.f. and reactive power regulator:

V877 KPQRF Gain p.f. / reactive power regulator 8.0 ... 16.0V957 TIQRF Integration time p.f. / reactive power regulator 0.02 ... 0.1 = 5 ... 10 s

13.4. CARRYING OUT COMMISSIONING

CAUTION

Before initial energizing of the excitation system the previously specified checklist according tochapter 13.1, "PREPARATION FOR COMMISSIONING" has to be gone through!

• The excitation system has to be connected with test supply.• The battery supplies has to be connected.• The battery supply for field flashing and current boosting has to be connected.• Switch on the mcb’s, -F71, -F81, -F83, -F84, -F09 and –F10• In case of optional dual channel switch on the mcb’s –F82, -F19 and –F20.• By closing of the mcb’s –F71, -F81 the first GMR3 rack –A01 is supplied with 24 Vdc, finally

the mcb –F01 on top of the GMR3 rach has to be switched on. After completion of the bootsequence of board MRB3 (approx. 8 sec.) and the User terminal (approx. a further 8 sec.) theregulator is ready for operation.

• Operating mode "MANUAL" has to be selected.

NOTE • These items of the commissioning instructions must be completed.• We recommend that these items of the commissioning instructions are to be fulfilled in order to ensure that the

safety for correct functioning of the integration is guaranteed.




13.4.1. Tests at Standstill

• Protection trip checks• Checking and measuring supply voltages in test mode• Check of thyristors voltage (=supply voltage) USYNIW (V37 = 0.9 ... 1.1). Only if V37 is out of

the range of 0.9 ... 1.1, this variable has to be calibrated as described in 13.3.1, “CalibrationPrinciple”

• Check of thyristors voltage frequency FSYNIW (V78 = +1.0)• During standstill operate the excitation ON key and slowly raise the field current until Ifn is

reached (or as far up as possible)• Check and calibration of the field current IPIW

At nominal field current has to be V500=1

è After that store setting parameter

13.4.2. Short Circuit Tests – If Applicable

• Operating mode "MANUAL" has to be selected• Generator terminal short circuited• Generator brought to nominal speed• Check of integrity of CT circuits whether all are closed but not short circuited with residual

current or minimum current (0.1p.u.)• Life trip check from a protection relay• Calibration of generator current IGIW as described in 13.3.1 Calibration Principle


13.4.3. Open Circuit Voltage Tests

• Operating mode "MANUAL" has to be selected• Generator terminal short circuit is removed• Generator brought to rated speed• Check of residual voltages at actual value input• Check of residual voltages at excitation transformer input• Excitation ON and raising excitation up to nominal voltage• Check of thyristor voltage USYNIW (V37 = 0.95 ... 1.05)• Check of thyristor voltage frequency FSYNIW (V78 = +1.0)• Calibration of generator voltage as described in 13.3.1, “Calibration Principle”• Check of voltages at all transformers• Optimization of current regulator gain (preliminary VPI=2, final adjustment in shunt field op-

eration mode)• Change over to voltage regulator mode (key "AUTO/MANUAL")• Change over to field current regulator mode (key "AUTO/MANUAL")• De-excitation• Change over from test- to shunt field supply• Operating mode "MANUAL"• Excitation ON, optimizing gain and integration time of current regulator• Change over to voltage "AUTO"• Optimizing gain and integration time of voltage regulator• De-excitation with voltage regulator• Check and optimizing of Soft-Start by excitation in voltage regulator mode to nominal voltage:

generator voltage must not swing over




• Start-up and de-excitation with voltage regulator• Oscilloscopic record of a set value jump 95 % à 105 % à 95 % Ugn• Oscilloscopic record of an excitation process from 0 to nominal voltage• Oscilloscopic record of a de-excitation process (operational de-excitation)• Generator shut down, 1 diode in excitation machine shorted or disconnected (for diode fault

supervision), run up unit to rated speed again.− Parameter V1003 (max. amplitude for trip) set to 15.0− Variable V518 (Supervision output signal) to be measured (should be 0.0)− Operating mode "MANUAL" has to be selected− Excitation ON, adjust field current to approximately ½ open circuit voltage value, but at

least 0,2 Ug− Variable V518 (Supervision output signal) to be measured (should be bigger as 1.0)− Variable V1003 (max. amplitude for trip) set just under value of V518 resulting in an excita-

tion trip− Generator shut down, remove diode short circuit or open circuit

• Check of remote operation control

• Prior to synchronizing: check CB intertrip


13.4.4. On Load Tests

NOTE

1) When after synchronizing the reactive current suddenly rises above 100 % Ign (generator over-excited and field current high) or drops to 40...80 % Ign (generator underexcited, field currentzero) and the voltage regulator does not get any response then the generator has to be imme-diately disconnected from the power system and the external wiring is to be checked becausethe CT polarity and/or CT allocation is incorrect.

2) When after synchronizing small changes of the setting value will result in considerable fluctua-tions of the reactive current then the reactive power static is to be increased in negative direc-tion. This is especially important when there is no generator-transformer and therefore no natu-ral static or when several generating units are connected in parallel.

After paralleling the generator to the grid system it can be observed that the response of reactivepower output is without influence on the active power. When the CT's and PT's are connected cor-rectly then after synchronizing the generator current will remain stable at a low level and can beadjusted with the voltage controller.

When the interrelation between set value changes and reactive power changes cannot be verifiedthe external wiring has to be re-checked again.




• Check current polarity (reactive current V504=IBIW, active current V505=IWIW)Positives sign:Current exportNegative sign:Current import

• Check actual value of active power (PWIW=V574) and reactive power (PBIW=V65)Positives sign:Power exportNegative sign:Power import

• Check actual value of power factor (CFR=V57)Calibrate generator current IGIW (if not performed as outlined in chapter 13.4.2, "Short CircuitTests – If Applicable" and described in 13.3.1, “Calibration Principle”

• Check of the regulator behavior by setpoint changes or setpoint steps (in on-load operationthe regulator behavior is different to no-load operation). If the regulation is not satisfactory, itcan be optimized by gain and integration time of the voltage regulator.

• Check reactive power static:1. Reactive power static V831 set to -0.02 (should already be 0.02)2. Select load position with reactive power export into grid.3. Increase reactive power static V831 step by step in negative direction (-0.03, -0.04),thereby the actual value of generator voltage and also the reactive current (reactive power)has to decrease (otherwise the CT connection is wrong).

• Measure the grid system static: XN = ............%Measuring procedures:Measuring of a load position (active current between 0...20 % Ign, p.f. approx.1): UG1, IB1(in p.u.)Increase voltage (reactive power), thenmeasuring of a second load position: UG2, IB2 (in p.u.)

XN UG UGUG IB IB= −

∗ − ∗2 11 2 1 100( ) (result XN in %)

• Load rejections at various loads with oscilloscope recording of the load rejection.• Smooth transfer between automatic- and manual operating mode (in both directions).• Check following limiters by approaching the limit value with the raise and lower commands.

- Field current limiter (max., delayed)- Stator current limiterWhen the respective limiter shows no response the calibration is not correct

• Setting following additional regulators:- power factor regulator / reactive power regulator

• Heat runDuring heat run following temperature rises are to be checked:Excitation transformer, cable connections, cubicle heating, etc.


13.4.5. Remaining Activities

• Final parameter saving• Check spare parts (if applicable) and set parameters on spare p.c.b’s• Write and distribute the commissioning test sheets

⇒ 1 copy for reasons of Quality Control and Service Support has absolutely to be sent toSAT-PE




14. TECHNICAL DATA

14.1. CHARACTERISTICS

14.1.1. Dimensions

The equipment has regarding the quantities of the options following dimensions• Single channel regulator and without redundancy in protection:

width x high x depth = 1200 x 2200 x 800 mm• Dual channel regulator and without redundancy in protection or

single channel regulator and with redundancy in protection:width x high x depth = 1200 x 2200 x 800 mm

• Dual channel regulator and redundancy in protection orwidth x high x depth = 1600 x 2200 x 800 mm

14.1.2. Excitation maximum capability

• Rated field current: 60 A• Permanent field current: 66 A• Ceiling current: 180 A• Ceiling time: 5 s

14.1.3. Rectifier capability

• Type: single phase, full wave controlled• Rated current: 85 A• repetitive peak reverse voltage: 1600 V

14.1.4. Field breaker capability

• Type: bipolar without mechanical latching• Rated current: 85 A

14.2. EMC COMPATIBILITY

The micro-processor system is manufactured according standard IEC 61000-4 and type tested byan international approved institute.

IEC 61000-4: EMC for industrial process automation• Part 1: General introduction• Part 2: ESD (Electrostatic discharge) class 4: 8 kV• Part 3: HF / Electromagnetic fields class 3: 10 V/m• Part 4: Fast transient / Burst class 4: 4 kV supply

2 kV input / output• Part 5: Surge immunity (1,2 / 50 µs) class 4: 4 kV




15. PLEASE NOTE!

COPYRIGHT, REMARKS

This document is the sole property of VA TECH SAT GmbH & Co and may neither be copied nordistributed and used without our written consent. Violations will be prosecuted by Law according toDIN 34 Standard.

The data contained in this literature should be considered as product information only. We wouldlike to advise that short term modifications of our production range are possible due to our aim tocontinuously improve the performance of our products for the benefit of our customers so theremay be differences between the products supplied and the corresponding descriptive literature.

According to our experience following the instructions outlined in this document will provide themost satisfactory service performance.

In case of unusual troubles which cannot be resolved by referring to this literature please contactour nearest agent or our Head Office.

When commissioning the operating instructions and also the applicable Local Safety Standardshave strictly to be observed.

This edition of the document has been carefully checked regarding up-to-date contents and cor-rectness. Should there be any discrepancies or contradictory information in this descriptive litera-ture could please inform us. In case of problems please do not try to solve them on your own butcontact our nearest agent or our Head Office who will be glad to be of any assistance to you.

All agreements, legal rights, obligations, performance and scope of supply for VA TECH SATGmbH & Co and also conditions governing the warranty are without expectation regulated ac-cording to the Contract Agreement and are not, in any way, influenced by the contents of the de-scriptive literature or operating instructions.

Urgent information will be conveyed by telephone or fax.

Our address:

VA TECH SAT GmbH & Co Phone: ++43 1 89 100 Ext. 2975Dept. PE Fax: ++43 1 89 100 Ext. 3878 Dept. FaxPenzingerstr. 76 ++43 1 894 60 46 Company faxA-1141 VIENNAAUSTRIA




To

VA TECH SAT GmbH & CoDept. PE / attn. Mr. HantschP.O.B. 5A- 1141 VIENNA

Please inform us at your earliest convenience if you have any additional requests andsuggestions or in case of errors.

We thank you for your cooperation.

Drawing No. of the documentation : ________________ revision (+date):______________

Remarks:

From: Phone:Address: Fax:

3 545 398a

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