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BHARAT HEAVY ELECTRICAL LIMITED,PSNRSummer Training Report, June 2011

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Company Profile

1956 - Company was set up at Bhopal in the name of M/s Heavy electrical (India) Ltd. In collaboration with AEI, UK. Subsequently, three more plants were set up at Hyderabad, Hardwar and Trichy. The Bhopal Unit was controlled by the company, the other three were under the control of Bharat Heavy Electricals Ltd. - The Company`s object is to manufacture of heavy electrical equipments. 1972 - In July the Operations of all the four plants were integrated. 1974 - In January Heavy electrical (India) Ltd was merged with BHEL. - For the manufacture of a wide variety of products, the company has developed technological infrastructure, skills and quality to meet the stringent requirements of the power plants, transportation, petro chemicals, oil etc. - BHEL has entered into collaboration which are technical in nature. Under these agreements, the collaborators have transferred, furnished the information, documentation, including know-how relating to design, engineering, manufacturing assembly etc. 1982 - BHEL also entered into power equipments, to reduce its dependence on the power sector.

BHEL has

1. Installed equipment for over 100000MW of power generation-for utilities, captive and industrial users.2. Supplied over 225000MW a transformer capacity and other equipment operating in transmission and distribution network up to 400Kv (AC& DC)3. Supplied over 25000 motors with drive control system to power projects, petro chemicals, refineries, steel, aluminum, fertilizers, cement plants etc.4. Supplied traction electrics and AC/DC locos to power over 12000kms railway network.5. Supplied over one million valves to power plants and other industries.

BHEL caters to core sectors of the Indian economy viz; power generation & transmission, industry, transportation, telecommunication, renewable energy, defence etc. the wide network of BHEL’s 14 manufacturing divisions, four power sector regional centers, over 100 project sites, eight service centers and 14 regional offices enables the company to be closer to its customers and provide them with suitable products, systems and services efficiently and at competitive prices. Having attained ISO 9000 certification, BHEL is now well on its journey towards total quality management (tqm). On the environmental management front, the major units of bhel have4 already acquired the ISO 14001 certification,


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Power sector

Power generation sector comprises thermal, gas, hydro and nuclear power plant business. As of 31-3-2004, BHEL supplied sets account for nearly 71,255 MW or 64% of the total installed capacity of 1,11,151 MW in the country, as against nil till 1969-70.

BHEL has proven turnkey capabilities for executing power projects from concepts to commissioning. It possesses the technology and capability to produce thermal sets with super critical parameters up to 1000 mw unit rating and gas turbine-generator sets of up to 250 mw units rating. Cogeneration and combined-cycle plants have been introduced to achieve higher plant efficiencies. To make efficient use of the high ash-content coal available in India, BHEL supplies circulating fluidized bed combustion boilers to both thermal and combined-cycle power plants.The company manufactures 235 MW nuclear turbine generator sets and has commenced production of 500 MW nuclear turbine generator sets. Custom-made hydro sets of Francis, Pelton and Kaplan types for different head discharge combinations are also engineered and manufactured by BHEL. In all, orders for more than 700 utility sets of thermal, hydro, gas and nuclear have been placed on the company as on date. The power plant equipment manufactured by BHEL is based on contemporary technology comparable to the best in the world, and is also internationally competitive. The company has proven expertise plant performance improvement through renovation, modernization and upgrading of a variety of power plant equipment, besides specialized know how of residual life assessment, health diagnostics and life extension of plants.

Transmission

BHEL also supplies a wide range of transmission products and systems of upto 400KV class. These include high voltage power & instrument transformers, dry type transformers, shunt & series reactors, sf switch gear, 33KV gas insulated substation capacitors, and insulators etc. for economic transmission of bulk power over long distances, High Voltage Direct Current (HVDC) systems are supplied. Series and shunt compensation systems, to minimize transmission loses, have also been supplied.


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Industry sector

BHEL is a major contributor of equipment and systems to industries: cement, sugar, fertilizer, refineries, petrochemicals, steel, paper etc. the range of systems and equipment supplied includes: captive power plants, dg power plants, high speed industrial drive turbines, industrial boilers and auxiliaries, waste heat recovery boilers, gas turbines, heat exchangers and pressure vessels, centrifugal compressors, electrical machines, pumps, valves, seamless steel tubes and process controls, control systems for process industries, and control and instrumentationsystems for power plants, defense and other applications. The company has commenced manufacture of large scale desalination plants to help augment the supply of drinking water to people.

Transportation

Mostly of the trains operated by the Indian railways, including the metro in Calcutta, are equipped with BHEL’s traction electrics and traction control equipment. The company supplies electric locomotives to Indian Railways and diesel shunting locomotives to various industries. 5000/4600 hp ac/dc locomotives developed and manufactured by BHEL have been supplied to Indian railways. Battery powered road vehicles are also manufactured by the company. BHEL also supplies traction electrics and traction control equipment for electric locos, dieselElectric locos, and EMUs/ DEMUs to the railways.

Telecommunication

Bhel also caters to telecommunication sector by way of small, medium, and large switching Systems.

Renewable Energy

Technologies that can be offered by BHEL for exploiting non-conventional and renewable resources of energy include: wind electric generators, solar power based water pumps, lighting and heating systems. The company manufactures wind electric generators of unit size up to 250 KW for wind farms, to meet the growing demand for harnessing wind energy.


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International Operations

BHEL has, over the years established its references in over 50 countries of the world, ranging from the united states in the west to New-Zealand in the far east. These references encompass almost the entire product range of BHEL, covering turnkey power projects of thermal, hydro and gas based type sub-station projects, rehabilitation projects, besides a wide variety of products, like switch gear, transformer, heat exchangers,insulators,castings and forgings. Apart from over 1100MW of boiler capacity contributed in Malaysia, some of the other major successes achieved by the company have been in Oman, Saudi Arabia, Libya,Greece,Cyprus,Malta,Egypt,Bangladesh,Azerbaijan,Srilanka,Iraq etc. execution of overseas projects has also provided BHEL the experience of working with world renowned consulting organizations and inspection agencies.

Technology Up gradation and Research and Development

To remain competitive and meet customers’ expectations,BHEL lays great emphasis on the continuous Up gradation of products and related technologies, and development of new products. The company has upgraded its products to contemporary levels through continuous in house efforts as well as through acquisitions of new technologies from leading engineering organizations of the world. The corporate r&d divison at Hyderabad leads BHEL’s research efforts in a number of areas of importance to BHEL’s product range. Research and product development centers at each of the manufacturing divisions play a complementary role. BHEL’s investment in R&D us amongst the largest in the corporate sector in India. Products developed in house during the last five years contributed about 8% to the revenues in 2003-04.

BHEL's vision is to become a world-class engineering enterprise, committed to enhancing stakeholder value. The company is striving to give shape to its aspirations and fulfill the expectations of the country to become a global player.The greatest strength of BHEL is its highly skilled and committed team of 46,748 employees. Every employee is given an equal opportunity to develop himself and grow in his career. Continuous training and retraining, career planning, a positive work culture and participative style of management have engendered development of a committed and motivated workforce setting new benchmarks in terms of productivity, quality and responsiveness.


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About the Pragati Power Plant, Bhawana

The plant is designed to generate 1500 MW of power upon its completion. The Liuefied Natural Gas has been chosen as the primary fuel for this power plant which will be supplied by GAIL.

The basic structure of the plant is shown below:

Power Plant(1500 MW)

Module 1 Module 2(750 MW) (750 MW)

Gas Turbine 1 Gas Turbine 2 Gas Turbine 3 Gas Turbine 4 (250 MW) (250 MW) (250 MW) (250 MW) HRSG HRSG HRSG HRSG

Steam Turbine Generator 1 Steam Turbine Generator 2(250 MW) (250 MW)


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Gas Turbine

Gas Turbine Internal view

The MS-9001FA is a single-shaft gas turbine designed for operation as a simple-cycle unit or in a combined steam and gas turbine cycle (STAG). The gas turbine assembly contains seven major sections.

» Air Inlet System » Compressor » Fuel Handling System » Combustion System » Turbine » Exhaust System » Lubricating System


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Combustion System Turbine Casing

Fuel Handling System Nozzle Arrangement

The above illustration shows the crossectional view of the arrangement.


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Heat Recovery Steam Generator (HRSG)A heat recovery steam generator or HSRG is an energy recovery heat exchanger that recovers heat from a hot gas stream.

The below two figures depicts a HRSG unit.

Figure 1

Figure 2


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Electrical Components of Generating station:

» Synchronous Generator• Gas Turbine Generator• Steam Turbine Generator

» Generator Circuit Breaker (GCB)» Generator Transformer» Station Auxiliary Transformer (SAT)» Excitation System (AVR)» HT & LT Switchgear

Battery System

• 220 V : For LT , HT, Controls & STG Emergency Drives• 125V : For GT , it’s auxiliaries & Control System• 24V : For Max DNA (DCS)• UPS (240V) : For HMI & Servers

Control System

• The main functions of the Mark VI turbine control system are as follows:

» Speed control during turbine start up » Automatic generator synchronization » Turbine load control during normal operation on the grid » Protection against turbine over speed on loss of load

The Mark VI turbine control system is discussed in detail in the following text.

MAX DNA Distributed Control System

• The complete system comprises of the following:» Distributed Processing Unit(DPU)» Input/output Modules» Redundant Ethernet Network(100 MBps)» Human Machine Interface


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Balance of Plant Systems

1. Water System Raw Water Clarified Water DM Water

2. Fire Fighting System Spray Water System Mulsifier

3. Compressor House Service Air Instrument Air

4. Cooling Towers Auxiliary Cooling Tower Main Cooling Tower


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Environment Setting of the Plant


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INTRODUCTION TO CONTROL SYSTEMS

India in the 21st century is being hailed as one of the countries which will play a major role in shaping the state and affairs of the world. Since liberalization of the economy in 1990-91, we have been making continuous progress in the fields of Science and Technology, Industry, Education, Infrastructure, Trade, Defense etc.. As we seem poised to move towards the vision of a developed India, it becomes very important that every requirement for this growth is met efficiently and rapidly. One of the most important of these requirements today is Electric Power and the need of power for the development of infrastructure, industry and the country can never be understated.

Coal based Power plants are the most dominant source of Electrical energy in our country today, besides Hydro electricity, Wind based energy and Nuclear energy. In a country like India, the importance of power for the development of infrastructure, industry and the country as a whole can never be understated.

As the country gears up to fulfill its power needs in the coming year, the role of BHEL has become very important. BHEL is engaged in the installation and commissioning of Power plants all over the country. Power plant construction is an extensive activity that requires a lot of planning co-ordination and technical expertise. It involves a range of activities like Planning, Procurement, Manufacturing, Construction, Erection and Commissioning. The power plant has a huge number of working parts and equipments which all need to work in a symphony to enable power generation in a safe and efficient manner.

Safe and efficient operation of a power plant requires that all the process variables and process conditions are kept at the desired values. This is made possible by continuous monitoring and correction of a large number of variables. These variables can be Pressure, Temperature, Level, Voltage, Current, Power, Speed, Frequency, Flow, Density, Moisture etc. A power plant may contain tens of thousands of such variables. This is where the need for a robust control system arises.

Control System is defined as the means by which any quantity of interest in a machine, mechanism or other equipment is maintained or altered in accordance with a desired manner. This definition brings us to the subject of the components in a control system.


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Need for C & I

Power Plant Control

Advantages of Control Systems

Operating personnel freed from routine tasks. Incorrect interventions in the process avoided. Stress on equipment reduced. Plant operations geared for maximum efficiency. Incipient faults recognized quickly. On fault occurrence, immediate and logical intervention possible.


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Components of a Control system:

Most control systems have a final control element (FCE), such as a valve, pump or compressor, that can receive and respond to a complete range of controller output (CO) signals between full on and full off. This would include, for example, a valve that can be open 37% or a pump that can be running at 73%.Our objective is to keep the measured process variable (PV) at the set point value (SP) in spite of unmeasured disturbances (D).

Considering a simple example of a Home heating system which needs to maintain the temperature inside a house at a comfortable value. The components in this case would be as below:

PV = process variable is house temperatureCO = controller output signal from thermostat to furnace valveSP = set point is the desired temperature set on the thermostat by the home ownerD = Heat loss disturbances from doors, walls and windows; changing outdoor

temperature; sunrise and sunset; rain...

To achieve this control objective, the measured process variable is compared to the thermostat set point. The difference between the two is the controller error, which is used in a control algorithm such as a PID (proportional-integral-derivative) controller to compute a output (CO) signal to the final control element (FCE).


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The change in the controller output (CO) signal causes a response in the final control element (fuel flow valve), which subsequently causes a change in the manipulated process variable (flow of fuel to the furnace). If the manipulated process variable is moved in the right direction and by the right amount, the measured process variable will be maintained at set point, thus satisfying the control objective.

Some further questions that the control system may need to answer in this case are:

Whether to open the valve or close the valve What should be the rate of opening or closing Should there be an alarm or annunciation if the process variable goes out of

control or any fault condition is generated.

The temperature being controlled may well be the temperature of the Re-Heater and Super-Heater in the boiler. The basic components remain the same in any such control system.

Turbine C&I package consists of the following systems:

A. CONTROL SYSTEM

ANALOG (CLOSE LOOP) - ELECTROHYDRAULIC CONTROLLER (EHC) - TURBINE STRESS EVALUATOR (TSE) - LOW PRESSURE BYPASS CONTROLLER (LPBPC) - GLAND STEAM PRESSURE CONTROLLER (GSPC)

BINARY (OPEN LOOP) - AUTOMATIC TURBINE RUN UP SYSTEM (ATRS) - AUTOMATIC TURBINE TESTER (ATT)

B. MONITORING & MEASUREMENT SYSTEM - TURBINE SUPERVISORY INSTRUMENTATION (TSI) - MEASURMENT OF PARAMETERS LIKE, TEMP.,PRESS.,LEVEL etc.

C. PROTECTION SYSTEM


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Heirarchy of Control System.


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MARK VI TURBINE CONTROL SYSTEM

Mark VI is used for the control and protection of steam and gas turbines in electrical generation and process plant applications.

The main functions of the Mark VI turbine control system are as follows:

• Speed control during turbine startup

• Automatic generator synchronization

• Turbine load control during normal operation on the grid

• Protection against turbine over speed on loss of load

The Mark VI system is available as a simplex control or a triple modular redundant (TMR) control with single or multiple racks, and local or remote I/O. The I/O interface is designed for direct interface to the sensors and actuators on the turbine, to eliminate the need for interposing instrumentation, and to avoid the reliability and maintenance issues associated with that instrumentation.


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System Architecture

It defines the architecture of the Mark VI turbine control system, including the system components, the three communication networks, and the various levels of redundancy that are possible. It also discusses system reliability and availability, and third-party connectivity to plant distributed control systems.

System Components

The following sections define the main subsystems making up the Mark VI control system. These include the controllers, I/O packs or modules, terminal boards, power distribution, cabinets, networks, operator interfaces, and the protection module.

Control CabinetThe control cabinet contains either a single (simplex) Mark VI control module or three TMR control modules. These are linked to their remote I/O by a single or triple high speed I/O network called IONet, and are linked to the Unit Data Highway (UDH) by their controller Ethernet® port. Local or remote I/O is possible. The control cabinet requires 120/240 V ac and/or 125 V dc power. This is converted to 125 V dc to supply the modules.

I/O CabinetThe I/O cabinet contains either single or triple interface modules. These are linked to the controllers by IONet, and to the terminal boards by dedicated cables. The terminal boards are in the I/O cabinet close to the interface modules. Power requirements are 120/240 V ac and/or 125 V dc power.

Unit Data Highway (UDH)The UDH connects the Mark VI control panels with the human machine interface (HMI) or HMI/Data Server. The network media is unshielded twisted pair or fiberoptic Ethernet. Redundant cable operation is optional and, if supplied, unit operation continues even if one cable is faulted. Dual cable networks still comprise one logical network. Similar to the plant data highway (PDH), the UDH can have redundant, separately powered network switches, and fiber-optic communication. Single mode cable (SMF) is now approved for the Mark VI UDH system. The advantage of SMF over multi-mode cable (MMF) is the cables can be longer because the signal attenuation per foot is less.


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UDH command data is replicated to all three controllers. This data is read by the master communication controller board (VCMI) and transmitted to the other controllers. Only the UDH communicator transmits UDH data (refer to the section,UDH Communicator).

Human-Machine Interface (HMI)Typical HMIs are computers running the Windows® operating system with communication drivers for the data highways, and CIMPLICITY® operator display software. The operator initiates commands from the real-time graphic displays, and views real-time turbine data and alarms on the CIMPLICITY graphic displays.Detailed I/O diagnostics and system configuration are available using the ToolboxST software. An HMI can be configured as a server or viewer, containing tools and utility programs.


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An HMI can be linked to one data highway, or redundant network interface boards can be used to link the HMI to both data highways for greater reliability. The HMI can be cabinet, control console, or table-mounted.

Computer Operator Interface (COI)The COI consists of a set of product and application specific operator displays running on a small panel computer (10.4 or 12.1 inch touch screen) hosting embedded Windows operating system. The COI is used where the full capability of a CIMPLICITY HMI is not required. The embedded Windows operating system uses only the components of the operating system required for a specific application. This results in all the power and development advantages of a Windows operating system in a much smaller footprint. Development, installation or modification of requisition content requires the ToolboxST®. The COI can be installed in many different configurations, depending on the product line and specific requisition requirements. The only cabling requirements are for power and for the Ethernet connection to the UDH. Network communication is through the integrated auto-sensing 10/100BaseT Ethernet connection. Expansion possibilities for the computer are limited, although it does support connection of external devices through floppy disk drives (FDD), intelligent drive electronics (IDE), and universal serial bus (USB) connections.The COI can be directly connected to the Mark VI or Excitation Control System, or it can be connected through an EGD Ethernet switch. A redundant topology is available when the controller is ordered with a second Ethernet port.

Link to Distributed Control System (DCS)External communication links are available to communicate with the plant DCS. A serial communication link, using Modbus protocol (RTU binary), can be supplied from an HMI or from a gateway controller. This allows the DCS operator access to real time Mark VI data, and provides for discrete and analog commands to be passed to the Mark VI control. In addition, an Ethernet link from the HMI supports periodic data messages at rates consistent with operator response, plus sequence of events (SOE) messages with data time tagged at a 1 ms resolution.

Control ModuleThe control module is available as an integrated control and I/O module, or as a stand-alone control module only. The integrated control and I/O rack can be either a 21-slot or 13-slot VME size. The 13-slot rack can accommodate all the boards for control of a small turbine. The backplane has P1 and P2 connectors for the VME boards. The P1 connectors communicate data across the backplane, and the P2


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connectors communicate data between the board and DC-37 pin J3 and J4 connectors located directly beneath each board. Cables run from the J3 and J4 connectors to the terminal boards.

Interface ModuleThe interface module houses the I/O boards remote from the control module. The rack, shown in the following figure is similar to the control module VME rack, but without the controller, interface board VDSK, and cooling fan. Each I/O board occupies one or two slots in the module and has a backplane connection to a pair of DC-37 pin connectors mounted on an apron beneath the VME rack. Cables run from the connectors to the terminal boards. Most I/O boards can be removed, with power removed, and replaced without disconnecting any signal or power cable.


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ControllerThe controller is a single-slot VME board, housing a high-speed processor, DRAM, flash memory, cache, an Ethernet port, and two serial RS-232C ports. It must always be inserted in slot 2 of an I/O rack designed to accommodate it. These racks can be identified by the fact that there are no J3 and J4 connectors under slot 2. The controller provides communication with the UDH through the Ethernet port, and supports a low-level diagnostic monitor on the COM1 serial port. The base software includes appropriate portions of the existing Turbine Block Library of control functions for the steam, gas, and Land-Marine aero-derivative (LM) products. The controller can run its program at up to 100 Hz, (10 ms frame rate), depending on the size of the system configuration.


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IONetThe IONet connection on the VCMI is a BNC for 10Base2 Ethernet. The interface circuit is high impedance that allows T tap connections with a 50 Ω terminal at the first and last node. The cabling distances are restricted to 185 meters (607 ft) per segment with up to eight nodes, using RG-58C/U or equivalent cable.

I/O BoardsMost I/O boards are single width VME boards, of similar design and front cabinet, using the same digital signal processor (TMS320C32). The central processing unit (CPU) is a high-speed processor designed for digital filtering and for working with data in IEEE 32-bit floating-point format. The task scheduler operates at a 1 ms and 5 ms rate to support high-speed analog and discrete inputs. The I/O boards synchronize their input scan to complete a cycle before being read by the VCMI board. Contact inputs in the VCCC and VCRC are time stampedto 1 ms to provide an SOE monitor.


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Each I/O board contains the required sensor characteristic library, for example thermocouple and resistance temperature devices (RTDs) linearizations. Bad sensor data and alarm signal levels, both high and low, are detected and alarmed. The I/O configuration in the toolbox can be downloaded over the network to change the program online. This means that I/O boards can accept tune-up commands and data while running.Certain I/O boards, such as the servo and turbine board, contain special control functions in firmware. This allows loops, such as the valve position control, to run locally instead of in the controller. Using the I/O boards in this way provides fast response for a number of time critical functions. Servo loops, can be performed in the servo board at 200 times per second. Each I/O board sends an identification message (ID packet) to the VCMI when requested. The packet contains the hardware catalog number of the I/O board, the hardware revision, the board barcode serial number, the firmware catalog number, and the firmware version. Also each I/O board identifies the connected terminal boards through the ID wire in the DC-37 pin cable. This allows each connector on each terminal board to have a separate identity.

Power SourcesA reliable source of power is provided to the rack power supplies from either a battery, or from multiple power converters, or from a combination of both. The multiple power sources are connected as high select in the PDM to provide the required redundancy.A balancing resistor network creates a floating dc bus using a single ground connection. From the 125 V dc, the resistor bridge produces +62.5 V dc (referred to as P125) and -62.5 V dc (referred to as N125) to supply the system racks and terminal boards. The PDM has ground fault detection and can tolerate a single ground fault without losing any performance and without blowing fuses. Since this fault is alarmed, it can be repaired.

Turbine Protection ModuleThe Turbine Protection Module (VPRO) and associated terminal boards (TPRO and TREG) provide an independent emergency overspeed protection for turbines that do not have a mechanical overspeed bolt. The protection module is separate from the turbine control, and consists of triple redundant VPRO boards, each with their own on-board power supply, as shown in the following figure. VPRO controls the trip solenoids through relay voting circuits on the TREG, TREL, and TRES boards.


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Operating SystemsAll operator stations, communication servers, and engineering workstations use the Windows operating system. The HMIs and servers run CIMPLICITY software, and the engineer's workstation runs toolbox software for system configuration. The I/O system, because of its TMR requirements, uses a proprietary executive system designed for this special application. This executive is the basis for the operating system in the VCMI and all of the I/O boards.The controller uses the QNX® operating system from QNX Software Systems Ltd.This is a real time POSIX®-compliant operating system ideally suited to high-speed automation applications such as turbine control and protection.

Networks

Data Highways

Plant Data Highway (PDH)The PDH is the plant level supervisory network. The PDH connects the HMI server with remote viewers, printers, historians, and external interfaces. The PDH has no direct connection to the Mark VI controllers, which communicate over the unit data highway (UDH). Using the Ethernet with the TCP/IP protocol over the PDH provides an open system for third-party interfaces.

Unit Data Highway (UDH)The UDH is an Ethernet-based network that provides direct or broadcast peer-to-peer communications between controllers and an operator/maintenance interface. It uses EGD, which is a message-based protocol for sharing information with multiple nodes based on UDP/IP. UDH network hardware is similar to the PDH hardware.

IONetIONet is an Ethernet 10Base2 network used to communicate data between the VCMI communication board in the control module, the I/O boards, and the three independent sections of the Protection Module <P>. In large systems, it is used to communicate with an expansion VME board rack containing additional I/O boards.These racks are called interface modules since they contain exclusively I/O boards and a VCMI. IONet also communicates data between controllers in TMR systems.


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PROFIBUS CommunicationsPROFIBUS is used in wide variety of industrial applications. It is defined in PROFIBUS Standard EN 50170 and in other ancillary guideline specifications.PROFIBUS devices are distinguished as masters or slaves. Masters control the bus and initiate data communication. They decide bus access by a token passing protocol. Slaves, not having bus access rights, only respond to messages received from masters. Slaves are peripherals such as I/O devices, transducers, valves, and such devices. PROFIBUS is an open fieldbus communication standard.

PROFIBUS Bus Lengthkb/s Maximum Bus Length in Meters9.6 120019.2 120093.75 1200187.5 1000500 4001500 20012000 100

Fiber-Optic CablesFiber-optic cable is an effective substitute for copper cable, especially when longer distances are required, or electrical disturbances are a serious problem.The main advantages of fiber-optic transmission in the power plant environment are:• Fiber segments can be longer than copper because the signal attenuation per foot is less.• In high-lightning areas, copper cable can pick up currents, which can damage the communications electronics. Since the glass fiber does not conduct electricity, the use of fiber-optic segments avoids pickup and reduces lightning caused outages.• Grounding problems are avoided with optical cable. The ground potential can rise when there is a ground fault on transmission lines, caused by currents coming back to the generator neutral point, or lightning.• Optical cable can be routed through a switchyard or other electrically noisy area and not pick up any interference. This can shorten the required runs and simplify the installation.• Fiber-optic cable with proper jacket materials can be run direct buried in trays or in conduit.• High-quality fiber-cable is light, tough, and easily pulled. With careful installation, it can last the life of the plant.


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Disadvantages of fiber optics include:• The cost, especially for short runs, may be more for a fiber-optic link.• Inexpensive fiber-optic cable can be broken during installation, and is more prone to mechanical and performance degradation over time. The highest quality cable avoids these problems.

Fiber-Optic ConverterFiber-optic connections are normally terminated at the 100BaseFX fiber port of the Ethernet switch. Occasionally, the Mark VI communication system may require an Ethernet media converter to convert selected UDH and PDH electrical signals to fiber-optic signals. The typical media converter makes a two-way conversion of one or more Ethernet 100BaseTX signals to Ethernet 100Base FX signals.

Media Converter

Time SynchronizationThe time synchronization option synchronizes all turbine controls, generator controls, and HMIs on the UDH to a Global Time Source (GTS). Typical GTS systems are Global Positioning Satellite (GPS) receivers such as the StarTime GPS Clock or similar time processing hardware. The preferred time sources are Coordinated Universal Time (UTC) or GPS.A time/frequency processor board, either the BC620AT or BC627AT, is placed in the HMI computer. This board acquires time from the GTS with a high degree of accuracy. When the HMI receives the time signal, it makes the time information available to the turbine and generator controls on the network through Network Time Protocol (NTP). The HMI Server provides time to time slaves either by broadcasting time, or by responding to NTP time queries, or by both methods. Refer to RFC 1305 Network Time Protocol (Version 3) dated March 1992 for details.Redundant time synchronization is provided by supplying a time/frequency processor board in another HMI Server as a backup. Normally, the primary HMI


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Server on the UDH is the time master for the UDH, and other computers without the time/frequency board are time slaves. The time slave computes the difference between the returned time and the recorded time of request and adjusts its internal time. Each time slave can be configured to respond to a time master through uni cast mode or broadcast mode.

Installation and Configuration

It defines installation requirements for the Mark VI control system.

Specific topics include GE installation support, wiring practices, grounding, typical equipment weights and dimensions, power dissipation and heat loss, and environmental requirements.

Early PlanningTo help ensure a fast and accurate exchange of data, a planning meeting with the customer is recommended early in the project. This meeting should include the customer’s project management and construction engineering representatives. It should accomplish the following:• Familiarize the customer and construction engineers with the equipment.• Set up a direct communication path between GE and the party making the customer’s installation drawings.• Determine a drawing distribution schedule that meets construction and installation needs.• Establish working procedures and lines of communication for drawing distribution.


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Tools and System Interface

Tool BoxThe toolbox is Windows®-based software for configuring and maintaining the Mark VI control system. The software usually runs on an engineering workstation or a CIMPLICITY HMI located on the PDH. For details, refer to GEH-6403, Control System Toolbox for a Mark VI Controller.IONet communicates with all the control and interface racks. This network topology is configured using the toolbox. Similarly, the toolbox configures all the I/O boards in the racks and the I/O points in the boards. the following figure displays the toolbox screen used to select the racks.The Outline View on the left side of the screen is used to select the racks required for the system. This view displays all the racks inserted under Mark VI I/O. In the example, three TMR Rack 0s are included under the heading Rack 0 Channel R/S/T(TMR).


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Product Features

The HMI contains a number of product features important for power plant control:• Dynamic graphics• Alarm displays• Process variable trending• Point control display for changing setpoints• Database logger• HMI access security• Data Distribution Equipment (DDE) application interface

The graphic system performs key HMI functions and provides the operator with real time process visualization and control using the following:

CimEdit is an object-oriented program that creates and maintains the user graphic screen displays. Editing and animation tools, with the familiar Windows environment, provide an intuitive, easy to use interface. Features include:

• Standard shape library• Object Linking and Embedding (OLE)• Movement and rotation animation• Filled object capabilities, and interior and border animation

CimView is the HMI run-time portion, displaying the process information in graphical formats. In CimView, the operator can view the system screens, and screens from other applications, using OLE automation, run scripts, and get descriptions of object actions. Screens have a 1-second refresh rate, and a typical graphical display takes 1second to repaint.Alarm Viewer provides alarm management functions such as sorting and filtering by priority, by unit, by time, or by source device. Also supported are configurable alarm field displays, and embedding dynamically updated objects into CimView screens.Trending, based on ActiveX technology, gives user’s data analysis capabilities.Trending uses data collected by the HMI or data from other third-party software packages or interfaces. Data comparisons between current and past variable data can be made for identification of process problems. Trending includes multiple trending charts per graphic screen with unlimited pens per chart, and the operator can resize or move trend windows to convenient locations on the display.


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The point control cabinet provides a listing of points in the system with realtime values and alarm status. Operators can view and change local and remote set points using the up/down arrows or by direct numeric entry. Alarms can be enabled and disabled, and alarm limits modified by authorized personnel.The basic control engine allows users to define control actions in response to system events. A single event can invoke multiple actions, or one action can be invoked by many events. The program editor uses a Visual Basic for Applications compliant programming language.Optional features include the Web Gateway that allows operators to access HMI data from anywhere in the world over the Internet. Third party interfaces allow the HMI to exchange data with distributed control systems, programmable logic controllers, I/O devices, and other computers.

Turbine HistorianThe Turbine Historian is a data archival system based on client-server technology.This provides data collection, storage, and display of power island and auxiliary process data. Depending on the requirements, the product can be configured for just turbine-related data, or for broader applications that include balance of plant process data.The Turbine Historian combines high-resolution digital event data from the turbine controller with process analog data creating a sophisticated tool for investigating cause-effect relationships. It provides a menu of predefined database query forms for typical analysis relating to the turbine operations. Flexible tools enable the operator to quickly generate custom trends and reports from the archived process data.


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Data FlowThe Turbine Historian has three main functions: data collection, storage, and retrieval. Data collection is over the UDH and Modbus. Data is stored in the Exception database for SOE, events, and alarms, and in the archives for analog values. Retrieval is through a web browser or standard trend screens.


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MAX DNA Control PackageBHEL’s control package is based on the maxDNA control system by Metso Automation USA. It is a Distributed Control System which divides the handling of Boiler, Turbine and Generator into smaller groups. Each of these groups is implemented in separate Remote Processing Units which are more commonly referred to as the Max Hardware Panels. The complete system comprises of the following:

1. Distributed Processing Unit(DPU)2. Input/output Modules3. Redundant Ethernet Network(100 MBps)4. Human Machine Interface

1) Distributed Processing Unit

A Distributed Processing Unit (DPU), which runs under the Windows CE.net real-time multitasking operating system, is the hardware processing engine of the maxDNA distributed control system. The DPU performs primary data acquisition, control, and data processing functions. The DPU comes under several versions, the most notable being the maxDPU4E and the maxDPU4F. At present BHEL uses the maxDPU4F series.

The maxDPU4F is a microprocessor based, rack-mounted unit, which occupies a single slot in a Remote Processing Unit cabinet using an 8-wide maxPAC backplane. It is designed to operate with user-defined combinations of Input/output Modules (maxDNA Model IOP). It also has the functionality to communicate with other devices, such as Programmable Logic Controllers and Remote Terminal Units.

As a station on maxNET, the DPU scans and processes information for use by other devices in the maxDNA system. The DPU is the heart of the system which enables us to program different logic and control schemes for controlling of output parameters. The main functions performed are:

• Comprehensive alarming and calculations.

• Logging of Sequence of Events (SOE) data at 1 millisecond resolution.


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• Acquisition of trend information.

• Continuous scanning of Model IOP I/O modules.

• Execution of predefined algorithms, called Function Blocks, for process control and data acquisition.

Fig 15 A distributed processing unit

2) Input/output Modules

The Model IOP Input/output System links the maxDNA Distributed Control System to real world process control inputs and outputs. The Input/output system uses a compact design to provide the system with greatly enhanced I/0 capacity in relatively little


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space. A close relationship exists, in turn, between this I/0 systems and the maxDNA Distributed Processing Unit (DPU) which it serves. Each module in a RPU has its own unique address which allows the DPU to communicate with it over an 8-bit asynchronous parallel bus.

Input/ Output modules are capable of accepting a wide variety of signals and giving a variety of outputs.

Input modules take input from the field in the form of current or voltage or digital pulses and provide them to the DPU over the backplane for further processing.

Similarly the Output modules deliver actuating signals in the form of Current, Voltage or digital pulses obtained from the DPU to the field components.

The basic forms of modules are:

Digital input modules: They take binary information from field components like Limit Switches, Pressure switches, Push buttons etc.

Digital Output Modules: They give binary outputs to field components like start impulses to motors, alarm indication etc.

Analog Input Modules: They accept continuous signals to enable measurement and monitoring of real world data like Pressure, Temperature, Feedback etc.

Analog Output Modules: They give continuous signal output to enable continuous control of field components like amount of opening of a valve, Display of measured valued for recorders and indicators.

A detailed list of the I/O module types, their nomenclature and specifications is given in appendix A at the end of the report.

3) Redundant Ethernet Network (100 MBps)

The different sets of RPU’s need to communicate with each other as well as the Operator workstations to enable the Human Machine Interface (HMI). MaxNET, the maxDNA dual Ethernet Network, interconnects all maxSTATIONs and RPUs in multiple systems allowing global access to all plant data.


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The maxNET Network provides a 100mbps full-duplex redundant communication network backbone with 10 mbps interface to each station. Should a network fail for any reason, communications will be maintained over the alternate network. Additionally, any cable failure will cause a system alarm.

Fast Ethernet Switches are used for interconnecting all nodes of the maxNET network. Each segment connected to the switch is a separate collision domain and is treated as a complete Ethernet segment capable of supporting the full length of cabling. Switches also prevent the propagation of defective packets to the rest of the network. Since each part of an Ethernet switch is an isolated network, problems on one segment, such as faulty wiring or a jabbering node will not affect the rest of the network.

The Fast Ethernet Switches used in maxNET can be managed from a maxSTATION using a Simple Network Management Protocol (SNMP) based manager. SNMP, the most popular management protocol used today, defines the structure of information maintained on a device being managed and the operations used to access the information.

4) Human Machine Interface

The HMI consists of the Operator work stations on which max runtime is installed. The workstations enable the user to interact with the system with the help of a Graphical User Interface. The workstation communicates with all the DPU’s over the maxNET and can be used to upload or download configurations to them. The maxstation has a number of utilities installed which allow the user to access, view and modify the contents of the system.

The main utilities available are:

4.1) Max DPUTOOLS: The max system uses a function block approach for implementing control logic. A lot of function blocks are pre-defined which can be used to build configuration database. The function blocks can be combined or modified to build required functionality into them.


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It is also important to define the various input/output points for the function blocks. All this is done by using the utility called as maxDPUTOOLS.

MaxDPUTOOLS is also used to load the configuration into the DPU by writing to the memory.

The maxDPUTOOLS is used to create a configuration for maxDPU based maxDNA systems. It can also be used to perform following functions:

Define the configuration for an individual maxDPU model 4E or 4F. Download the configuration to an individual maxDPU. Create sets of configurations representing the maxDPUs in a system. Upload and save the complete contents of an individual maxDPU. Perform differences with a running maxDPU and selectively save any

changes resulting from online edits. Perform differences with a previous copy of the configuration to review any

changes resulting from editing. Export from maxDPUTOOLS to Access or a formatted file. Import configuration data from Access or a formatted file. Convert an earlier release version configuration.

4.2) Point Browser:

Point Browser is used to monitor a working configuration and to change attribute values, reference pointers and point identifiers online. This is an easy way to edit a configuration, test configuration changes and view the results on a working system.

The browser consists of a two-pane window similar in appearance to a Windows Explorer file directory. A tree-style directory appears in the left pane. When you select a service name appearing in the left tree directory, an associated tabular detail display appears in the right pane listing all the attributes available with the selected service name.


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The Graphical Configurator, available through the maxVUE Editor, allows you to represent a point database graphically in the form of logic diagrams positioned on printable sheets. Use the Graphical Configurator application to:

Create graphical representations of point databases Make online edits to a configuration Edit tag names Add and delete atomic and custom blocks online Copy and paste Document and print graphical representations of configurations

4.3) maxVUE RUNTIME:

It is the Visual User Interface which allows the user to view the system and interact with it. MaxVUE runs like a standard windows application and responds to the mouse and keyboard like any other standard program.

Within maxVUE, mice or equivalent pointing devices can be used to click display buttons ,to move between displays, perform control functions, and respond to alarm conditions. Buttons and other Windows features can be used, such as dialog boxes and scroll bars.


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A typical maxVUE window showing the GCS is shown below:

Fig: A maxVUE window showing the GCS


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References:

1. Wikipedia.2. NTPC Environment Impact Assessment Report.3. Scribd.4. General Electric, MARK VI Control System Guide.5. BHEL Website.

Project Report By:Kushagra TrivediElectronics DepartmentBharati Vidyapeeth University-COE.Pune.Email: [email protected]

summer training report_bhel_1_ashwin aggarwal repaired)

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