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REGISTRO BRASILEIRO RBNA Special Rules Diesel Electric Propulsion

DE NAVIOS E AERONAVES for Diesel-Electric

RGEP18EN Propulsion Systems Chapters – A,B,D,E,F,G,H and T

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PART II RBNA Special Rules

RULE FOR DIESEL ELECTRIC PROPULSION

SYSTEMS

CHAPTERS

A APPROACH

B DOCUMENTS, REGULATIONS AND

STANDARDS

C MATERIALS AND MANUFACTURING

See Rules for the Construction and Classification of

Steel Ships, inland or open sea navigation, Part II,

Title 11 and Section 7

D PRINCIPLES OF INSTALLATION

E BASIC DESIGN PRINCIPLES

F DESIGN AND INSTALLATION OF THE

ELECTRICAL POWER SYSTEM

G DESIGN AND INSTALLATION OF THE

ELECTRICAL POWER DISTRIBUTION

SYSTEM




H DESIGN AND INSTALLATION OF THE

POWER CONSUMERS – LIGHT AND

MOTORS

I SYSTEMS WITH VOLTAGES ABOVE 1 KV UP

TO 15 KV




T TEST OF ELECTRICAL INSTALLATIONS




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CHAPTER A ...................................................................... 3

APPROACH ....................................................................... 3

A1. APPLICATION ................................................... 3 100. Scope ................................................................ 3 200. General description .......................................... 3

A2. DEFINITIONS ..................................................... 4 100. Terms employed in this Rule ............................ 4

CHAPTER B ...................................................................... 5

DOCUMENTS, REGULATIONS AND STANDARDS . 5

B1. DOCUMENTATION ........................................... 5 100. Submission of documents ................................. 5 200. Documents of installation for ships with diesel

electric propulsion ....................................................... 5 300. Documents related to changes ......................... 5 400. References ........................................................ 5

B2. REGULATIONS .................................................. 6 100. Class requirements from other RBNA Rules .... 6 200. Statutory requirements ..................................... 6

B3. STANDARDS AND UNITS ................................ 6 100. Standards ......................................................... 6 200. Units ................................................................. 6

CHAPTER D ...................................................................... 6

PRINCIPLES OF CONSTRUCTION ............................. 6

D2. LOCATION OF THE DIESEL-ELECTRIC

EQUIPMENT .................................................................. 6 100. Requirements for the location of the Diesel-

electric propulsion equipment ...................................... 6

CHAPTER E ...................................................................... 7

BASIC DESIGN PRINCIPLES ........................................ 7

E1. GENERAL REQUIREMENTS FOR THE

SYSTEM .......................................................................... 7 100. General requirements ...................................... 7

E2. VOLTAGE AND FREQUENCY VARIATIONS 7 IACS UR E5 ..................................................................... 7

100. Voltage and frequency variations .................... 7 200. Harmonic distortions ....................................... 8

CHAPTER F ...................................................................... 8

DESIGN AND INSTALLATION OF THE

ELECTRICAL POWER SYSTEM .................................. 8

F1. PRIME MOVERS FOR INTEGRATED POWER

AND PROPULSION PLANTS ........................................ 8 100. Prime movers for integrated power and

propulsion plants ......................................................... 8 200. Speed governor, overspeed protective and

governing characteristics of generator prime movers . 8 F2. GENERATORS FOR INTEGRATED

PROPULSION PLANTS ............................................... 10 100. Application ..................................................... 10 200. Generator and motor excitation ..................... 10 300. Voltage control ............................................... 11 400. Overspeed ...................................................... 11 500. Short circuit ................................................... 11 600. Emergency generators ................................... 11

F3. POWER MANAGEMENT SYSTEMS ............. 11

100. Power management requirements .................. 11 F4. ALARMS AND PROTECTIONS ...................... 12

100. Alarm and safety system ................................. 12 200. Protections and alarms .................................. 12 300. Additional requirements ................................. 14

F5. FAILURE MODE AND EFFECT ANALYSIS.. 15 100. FMEA ............................................................. 15

CHAPTER G .................................................................... 15

DESIGN AND INSTALLATION OF THE POWER

CONSUMERS – LIGHT AND MOTORS ..................... 15

G1. PROPULSION MOTORS .................................. 15 100. Application ..................................................... 15

G2. PROPULSION POWER CONVERSION

EQUIPMENT ................................................................. 15 100. Requirements for power converters ................ 15

G3. PROPULSION DRIVE TRANSFORMERS ...... 16 100. Requirements for propulsion transformers..... 16

G4. SWITCHBOARDS ............................................ 16 100. Application ..................................................... 16 200. Requirements for design and installation ....... 16

G5. POD UNITS ....................................................... 16 100. Pod units ......................................................... 16

CHAPTER H .................................................................... 17

AUXILIARY SYSTEM ................................................... 17

H1. REQUIREMENTS FOR AUXILIARY SYSTEMS

OF THE DIESEL ELECTRIC PROPULSION SYSTEMS

17 100. Requirements for auxiliary systems ................ 17

CHAPTER T .................................................................... 17

TEST OF ELECTRICAL INSTALLATIONS .............. 17

T1. TESTS AT MANUFACTURER ........................ 17 100. Equipment acceptance and certification tests 17

T2. QUAY AND SEA TRIALS ................................ 17 100. Tests and Trials .............................................. 17




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CHAPTER A

APPROACH

CHAPTER CONTENTS

A1. APPLICATION

A2. DEFINITIONS

A1. APPLICATION

100. Scope

101. The present Rules apply to all ships fitted with

diesel electric propulsion, irrespective of their tonnage or

navigation area.

102. RBNA reserves the right to allow deviations from

these Rules on ships classified for limited service, with

restrictions on navigation or GT < 500 (depending on each

specific case), however this may not be taken as a precedent

for future amendments of the Rules. Moreover, additional

requirements may be requested for vessels having special

construction features.

103. Designs and facilities whose characteristics differ

from the Rules, set forth herein may be approved, provided

that they are recognized by RBNA and their equivalence

with other regulations and standards is no less effective than

the Rules. Additional documents may be required, as well

as special tests and trials.

104. A Class Notation DEP is assigned to ships in

compliance with the present Additional Rules. Redundant

propulsion is a voluntary class notation, DEPR, assigned for

ships where a single failure will result in a 50% loss of

propulsion. An FMEA is required for the complete

propulsion and steering systems and their auxiliaries, to

show that these requirements are met.

200. General description

201. Diesel-electric propulsion systems are typically

comprised of one or more generator sets driven by diesel

engines, main switchboards, a converter (frequency

converter or variable speed drive) and electric propulsion

motors. A transformer may be required to be installed

dependent on the type of converters.

202. Special attention is given to availability, which

means that in a diesel electric propulsion system redundancy

is required. Where there is only one transformer, converter

and motor the inspections at the manufacturer should ensure

the quality and reliability of the equipment.

203. The prime movers are normally one or more diesel

engines of medium to high speed, driving a DC or AC

power generation plant.

204. The generator plants may be fitted with AC or DC

distribution. Generators are usually the brushless type

synchronous machines.

205. The main switchboards are usually split in two or

more sections for redundancy purposes.

206. The generator sets and main switchboards may be

integrated, i.e., supplying the propulsion system and the ship

services, or dedicated to the propulsion system.

207. Transformers are used to supply the propulsion

system to feed converters, e.g. variable speed drives, in

order to reduce distorted currents, which in turn reduces the

voltage distortion for generators and other consumers.

Transformers are also used in the power supply of the ship

service systems.

208. Power converters may be of different types,

typically:

- Voltage source inverter (VSI) type converters for AC

motors, normally asynchronous motors

- Cycloconverters (Cyclo) for AC motors, normally for

synchronous motors

- Current source inverter type (CSI) converters for AC

motors, normally synchronous motors

- DC converters, or SCR (Silicon Controlled Rectifier)

for DC motors

However, basically AC motors require frequency converters,

while DC systems require variable speed drives.

209. Electric motors are used for conversion from

electrical power to mechanical power. The electric motors

typically are:

a. DC motors which must be fed from a DC supply, and

since the power generation and distribution system

normally is a three-phase system, this means that a DC

motor must be fed from a thyristor rectifier. This gives

also a speed control of the motor.

b. Asynchronous (induction) motors: The asynchronous

motor is used in any applications, either as a constant

speed motor directly connected to the network, or as a

variable speed motor fed from a static frequency

converter.

c. Synchronous motors: The synchronous machine is

normally not used as a motor in ship applications, with

exception of large propulsion drives, typically > 5MW

directly connected to propeller shaft, or > 8-10MW with

a gear connection. The design of a synchronous motor

is similar to that of a synchronous generator. It is

normally not used without a frequency converter supply

for variable speed control in ship applications.

210. The diesel-electric propulsion system is managed

by a Power Management System (PMS) whose purpose is to




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ensure that there is sufficient available power for the actual

operating conditions.

211. The power management system can also have

extended functionality by monitoring and control of the

energy flow for optimum fuel efficiency. Such systems can

be called Energy Management System (EMS).

A2. DEFINITIONS

100. Terms employed in this Rule

101. Converter - A circuit that converts AC to DC or

from DC to AC or acts as AC frequency changer. Modern

electric drive systems, in which speed control of the electric

motor is required, use power supply converters. These

converters adapt the voltage and frequency of the power

supply to the electric motor as required for the desired motor

speed. The basic components of the converters are diodes,

transistors and thyristors.

102. Cyclo-converter – A cyclo-converter is a single-

stage (AC-AC) converter and converts AC with a constant

frequency directly to an AC with a varying frequency, as

required for the desired motor speed. Cyclo-converters are

used to power and control the speed of synchronous motors.

Motor speed is adjusted by changing the frequency of the

motor’s supply and allows full torque over the speed range

in either direction. As cyclo-converters produce relatively

low frequencies, they are more associated with direct drive

low-speed motors.

103. Pulse Width Modulation (PWM) converter –

PWM converter has a dual conversion process (AC-DC-AC)

and uses a DC link. PWM converters are used to power and

control the speed of asynchronous motors. Pulse width

modulation (PWM) uses a rectifier to create DC voltage in

the same way as a synchro-converter. On the inverter side it

uses forced commutation to give a series of pulses of

common voltage both positive and negative. In this way the

output voltage can be made to approximate AC, while

varying of the pulse number and width can increase or

decrease the frequency. In marine propulsion terms they are

at the low end of the power band (up to 8MW) and as

frequency increases, the output wave becomes increasingly

distorted.

104. Synchro-converter – Synchro-converter is AC-

DC-AC converter. It converts three phase AC with a

constant voltage and frequency to a DC with a varying

voltage and then again to a three phase AC with varying

voltage and varying frequency. It can be used only in

combination with a synchronous motor. To increase the

motor speed, the current is increased, which creates higher

magnetic forces and torque. This, in turn, causes the rotor to

move faster which commutates the thyristors more quickly,

increasing the AC frequency until the required speed is

reached.

Note: Synchro-converters can produce frequencies in excess

of 100Hz and are suited to high-speed motors.

105. Flashover - Flash-overs occur on main generators,

motors, etc. A flash-over is the dissipation of a large

amount of electrical energy from the positive point to the

negative or earth. In the case of the main generator this

energy flashes in the form of a large arc from the positive

sets of brushes to the negative sets, or the earthed iron work

of the machine, through the intervening air space.

http://www.wartsila.com/encyclopedia/term/diode

http://www.wartsila.com/encyclopedia/term/thyristor




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CHAPTER B

DOCUMENTS, REGULATIONS AND STANDARDS

CHAPTER CONTENTS

B1. DOCUMENTATION

B2. REGULATIONS

B3. STANDARDS AND UNITS

B1. DOCUMENTATION

100. Submission of documents

101. Drawings and documents are to be submitted to

RBNA for approval in three hard copies or virtual files are

to be submitted. Where hard copies are submitted, RBNA

will retain two copies and return one with the approval.

102. The plans, diagrams and specifications indicated as

following, equipment and components for electrical

systems, where applicable, are to be submitted to the

approval of the RBNA, before starting the installation on

board the ship, indicating at least, the location of essential

service equipment, distribution of the circuits, rated current

for each extension and circuit protection devices.

200. Documents of installation for ships with diesel

electric propulsion

201. In addition to the requirements in the RBNA Rules

for the Construction and Classification of Steel Ships for

inland or open sea navigation, Part II, Title 11, Section 7, at

least the following documents, are to be submitted for

approval, as a minimum:

a. Electric one-line diagrams for the propulsion

system;

b. Monitoring, alarm and safety systems one line

diagrams and specifications;

c. Arrangement of the machinery spaces, including a

description of the propulsion system, main and

emergency electrical power supply systems are to

be submitted. The plans are to indicate segregation

and access arrangements for machinery spaces and

associated control rooms/stations;

d. Arrangement and diagram of the main switchboard

and all control panels;

e. Diagrams and specification for the system

components such as converters, transformers,

motors;

f. Air and other cooling systems for the converters,

transformers and motors, where applicable;

g. Maneuvering capability: an assessment of the

ships’ ahead and astern maneuvering capability,

according to IMO Resolution A.751(A) Interim

Standards for Ship Maneuverability, is to be

submitted for guidance on standard maneuvers

required;

h. Failure Mode and Effects Analysis (FMEA:

required for notation DEPR. RBNA may request

an FMEA analysis for class notation DEP.

i. Harmonic distortion calculations;

j. Torsional stress and vibration calculation of the

movable parts of the system (see E1.104 below);

and

k. Testing and trials procedures: a schedule of testing

and trials to demonstrate that the ship is capable of

being operated according to the requirements of the

present Rule is to be submitted. In addition, any

testing program that may be necessary to prove the

conclusions of the FMEA is to be submitted.

300. Documents related to changes

301. In the case of temporary or permanent increasing of

the load capacity of existing vessels or change in the

characteristics of electrical equipment and components of

ships under construction, the relevant documentation is to be

submitted to the examination and approval of the RBNA.

400. References

401. The present Rule has been based on the following

references:

- IEEE Standard 45-2002

- ABB AS Maritime Electrical Installations and Diesel

Electric Propulsion

- MAN Diesel-electric Propulsion Plants Guideline

- THYSSEN KRUPP Marine System Diesel-electric

Propulsion Concepts

- TRANSPORT CANADA Ship Electric Standards

TP/12 E

- SIMENS The Rule of Marine Frequency Converters

- Power Electronic Converters for ShipPropulsion

Electric Motors - Damir Radan - Department of Marine

Technology, NTNU

- CARRIER - Variable Frequency Drive




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B2. REGULATIONS

100. Class requirements from other RBNA Rules

101. Requirements from the RBNA Rules for

Construction and Classification of Steel Vessels According

to their Missions, for inland or open sea navigation,

applicable to this Rule:

Prime movers (Internal Combustion Engines):

Part II, Title 11, Section 5, Chapter E.

Electric Generators:

Part II, Title 11, Section 7, Subchapter F5.

Rotary machines:

Part III, Title 63, Section 7, Chapter A.

Piping Systems:

Part II, Title 11, Section 6.

Electric installations in general:

Part II, Title 11, Section 7.

200. Statutory requirements

201. The requirements of NORMAM 01 (Standard of

the Brazilian Maritime Authority for ships employed in

navigation in open seas) are to be satisfied and/or of the

IMO conventions, codes and resolutions where applicable.

202. The texts referred to statutory regulations are

marked with a border line in the left margin, as exemplified

in this very paragraph.

B3. STANDARDS AND UNITS

100. Standards

101. The electrical installations and all the equipment

and materials to be employed on vessels covered by these

Rules are to be designed, constructed and tested according

to the latest revisions of the applicable Standards of the

following organizations, in addition to the requirements laid

down in these Rules:

a. INMETRO: National Institute of Metrology,

Standardization and Industrial Quality;

b. ABNT: Brazilian Association of Technical

Standards;

c. IEC: International Electrotechnical Commission;

d. ANSI: American National Standards Institute;

e. NEMA: National Electrical Manufactures

Association;

f. IEEE: Institute of Electrical and Electronics

Engineers.

200. Units

201. Drawings and documents to be submitted to the

RBNA are to have all the dimensions given in the

international unit system. Consecrated dimensions in other

systems of units shall have indications of the corresponding

values in the international system.

CHAPTER D

PRINCIPLES OF CONSTRUCTION

CHAPTER CONTENTS

D1. INSTALLATIONS ON BOARD



Title 11, Section 7, Chapter D, Subchapter D1.


EQUIPMENT


EQUIPMENT

100. Requirements for the location of the Diesel-

electric propulsion equipment

101. Provision shall be made for the inspection and

maintenance access to stator winding and armature coils and

for the withdrawal and replacement of the coils of DC

machines and of salient-pole AC machines.

102. The system is to be localized in compartments

attending to the following requirements:

a. Not exposed to mechanical damage or leaking

fluids;

b. Ventilated compartments free from the

accumulation of flammable gases and/or vapors;

c. Not affected by oily water accumulated in the

engine room bilges.




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CHAPTER E

BASIC DESIGN PRINCIPLES

CHAPTER CONTENTS


SYSTEM

E2. VOLTAGE AND FREQUENCY VARIATIONS


SYSTEM

100. General requirements

101. The power and torque available in the system shall

be sufficient for:

a. Stopping or reversing the ship at maximum speed

b. Avoid failure in synchronism during maneuvers

c. Overload during starting and maneuvers

d. Sufficient power for propulsion and for ship’s

loads, where an integrated electric power system is

installed

102. The drive train and all its components are to be

built with redundancy so that a single failure will not

completely disable the propulsion of the vessel. The

system shall be fitted with redundancy so that:

a. Where electric motors provide the sole means of

propulsion for a vessel, a single propulsion motor

with dual windings does not meet the requirement for

DEPR;.

b. Where there is one engine and one converter, there shall

be redundancy either of the static converter for notation

DEPR with redundancy, or a double stator winding for

notation DEP without redundancy;

c. Where there are more than one generator and converter

driving one shaft line, the malfunction or tripping of

one component shall not affect the other;

d. Where there are more than one shaft line driven by one

or more generators and converters, the malfunction or

tripping of one component shall not affect the others.

103. The continuous power of the motors is to be

protected against overload.

104. A torsional stress and vibration calculation is to be

submitted to RBNA considering the coordination of the

mass constants, elasticity constants and electrical

characteristics of the system, therein including prime

movers, generators, converters, exciters, motors, couplings,

gearing, shafting and propellers.

105. All important circuits, instruments and apparatus

shall be clearly labelled for identification.

106. Provision shall be made for the main propulsion

circuit to be provided with ground leakage indicating

devices that will operate when the insulation resistance is

100,000 Ohms or less.

107. Electric slip couplings shall be of substantial and

rigid construction, and shall be enclosed, ventilated or

otherwise provided with substantial wire or mesh screen to

prevent injury to personnel or the entry of foreign material?

108. The electric propulsion system may be utilized by a

dynamic positioning system. In this case, the requirements

of Part II, Title 103, Section 8 of the RBNA Rules for open

sea navigation should then apply for the propulsion system,

in addition to the requirements in the present Rules for

Diesel Electric Propulsion, in particular the redundancy

requirements.

E2. VOLTAGE AND FREQUENCY VARIATIONS

IACS UR E5

100. Voltage and frequency variations

101. All electrical appliances supplied from the main or

emergency systems are to be capable of operating

satisfactorily under variations in voltage and frequency the

occurring during normal operation.

102. Unless otherwise stated in the national or

international standards, all equipment shall operate

satisfactorily with the variations from its rated value shown

in the T.E2.102.1 and T.E2.102.2:

a. For alternative current components, voltage and

frequency variations shown in the T.E2.102.1 are to be

assumed.

b. For direct current components supplied by DC

generators or converted by rectifiers, voltage variations

shown in the T.E2.102.2 are to be assumed.

103. Any special system, e.g. electronic circuits, whose

function cannot operate satisfactorily within the limits

shown in the tables below, shall not be supplied directly

from the system but by alternative means, e.g. through

stabilized supply.




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TABLE T.E2.102.1 – VOLTAGE AND FREQUENCY

VARIATIONS

Quantity in

operation

Variations

Permanent Transient

Voltage ±5% ±10% (5 seg)

Frequency +6%, -10% 20% (1,5 seg)

TABLE T.E2.102.2 – VOLTAGE VARIATIONS FOR

DC DISTRIBUTION SYSTEMS

Parameters Variations

Voltage tolerance (continuous) ±10%

Voltage cyclic variation deviation 5%

Voltage ripple (a.c. r.m.s. over steady

d.c. voltage) 10%

200. Harmonic distortions

201. Harmonic distortions are to be calculated according

to IEEE 519-1992 standard or equivalent.

202. Measurements are to be taken at all conditions of

operation.

203. Transformers, filters or rotary converters are to be

used to keep the harmonic distortions within allowed limits.

204. Failure of fuses in harmonic filter circuits shall be

detected.

205. The calculation of harmonics to the system and to

other semiconductor converters shall conform to the

standard IEEE 519 Recommended Practices and

Requirements for Harmonic Control of Electric Power

Systems.

CHAPTER F

DESIGN AND INSTALLATION OF THE

ELECTRICAL POWER SYSTEM

CHAPTER CONTENTS

F1. PRIME MOVERS FOR INTEGRATED POWER

AND PROPULSION PLANTS

F2. GENERATORS FOR INTEGRATED

PROPULSION PLANTS

F3. POWER MANAGEMENT SYSTEMS

F4. ALARM AND SAFETY SYSTEMS

F5. FAILURE MODE AND EFFECT ANALYSIS

F1. PRIME MOVERS FOR INTEGRATED

POWER AND PROPULSION PLANTS

100. Prime movers for integrated power and

propulsion plants

101. Prime movers for the diesel electric propulsion

system shall be capable of starting from a dead ship

condition without external help.

102. The prime mover rated power is to be sufficient to

supply the necessary power during operational conditions

without tripping from overspeed, such as maneuvering and

rough sea conditions, as well as part of the regenerated

power generated during emergency stop.

103. The manufacturers of the electrical and mechanical

machinery are to agree to the amount of the regenerated

power to be absorbed in order to prevent overspeeding.

104. Prime movers for driving generators of the main

and emergency sources of electrical power are to be fitted

with a speed governor in accordance with F2.400 F1.200

below.

200. Speed governor, overspeed protective and

governing characteristics of generator prime

movers

[IACS UR M 3.2]

201. Prime movers for driving generators of the main

and emergency sources of electrical power are to be fitted

with a speed governor which will prevent transient

frequency variations in the electrical network in excess of

±10% of the rated frequency with a recovery time to steady

state conditions not exceeding 5 seconds, when the

maximum electrical step load is switched on or off.

a. The setting of the overspeed trip device shall

automatically shut down the unit when the speed




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exceeds the designed maximum service speed by more

than 15%.

b. In addition to the speed governor, each prime mover

driving an electric generator and having a rated power

of 220 kW and above must be fitted with a separate

overspeed protective device so adjusted that the speed

cannot exceed the rated speed by more than 15%.

202. The protective equipment shall be capable of being

set as not to be activated on the overloads or excess currents

likely to be experienced in a heavy seaway or when

maneuvering.

203. Electronic governors controlling the speed of a

propulsion unit shall have two power supplies, one of which

shall be a battery.

a. in the event of a "normal" supply failure the governor

shall be automatically transferred to the alternative

battery power supply;

b. an audible and/or visual alarm shall be provided in the

main machinery control area to indicate that the

governor has transferred to the battery supply;

c. the prime-mover shall be equipped with a separate

overspeed device to prevent runaway if a failure shall

render the governor inoperative;

d. the alternative battery supply shall be arranged for

trickle charge to ensure the battery is always in a fully

charged state;

e. each governor shall be protected separately so that a

failure in one governor will not cause failure in other

governors;

f. a mechanical back-up governor may be provided in lieu

of the alternative battery supply; the mechanical

governor shall be of a suitable type and shall

automatically assume control of the engine in the event

of electronic governor failure.

a. location, preferably the generator control panel.

IACS

204. In the case when a step load equivalent to the rated

output of a generator is switched off, a transient speed

variation in excess of 10% of the rated speed may be

acceptable, provided this does not cause the intervention of

the overspeed device.

205. At all loads between no load and rated power the

permanent speed variation shall not be more than ±5% of the

rated speed.

206. Prime movers are to be selected in such a way that

they will meet the load demand within the ship’s mains.

Application of electrical load shall be possible with 2 load

steps and must be such that prime movers – running at no

load – can suddenly be loaded to 50% of the rated power of

the generator followed by the remaining 50% after an

interval sufficient to restore the speed to steady state.

207. Steady state conditions shall be achieved in not

more than 5 seconds.

208. Steady state conditions are those at which the

envelope of speed variation does not exceed +1% of the

declared speed at the new power.

209. Application of electrical load in more than 2 load

steps can only be permitted, if the conditions within the

ship’s mains permit the use of such prime movers which can

only be loaded in more than 2 load steps (see Figure

F.F2.209.1) and provided that this is already allowed for in

the designing stage.

210. This is to be verified in the form of system

specifications to be approved and to be demonstrated at

ship’s trials. In this case, due consideration is to be given to

the power required for the electrical equipment to be

automatically switched on after black-out and to the

sequence in which it is connected.

211. This similarly applies for generators to be operated

in parallel and where the power has to be transferred from

one generator to another in the event any one generator has

to be switched off.

212. For AC generating sets operating in parallel, the

governing characteristics of the prime movers shall be such

that within the limits of 20% and 100% total load the load

on any generating set will not normally differ from its

proportionate share of the total load by more than 15% of

the rated power of the largest machine or 25% of the rated

power of the individual machine in question, whichever is

the less.

213. For an a.c. generating set intended to operate in

parallel, facilities are to be provided to adjust the governor

sufficiently fine to permit an adjustment of load not

exceeding 5% of the rated load at normal frequency.

Note: For guidance, the loading for 4-stroke diesel engines

may be limited as given by Figure F.F2.209.1.




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FIGURE F.F2.209.1 - LIMITING CURVES FOR

LOADING 4-STROKE DIESEL ENGINES STEP BY

STEP FROM NO-LOAD TO RATED POWER AS A

FUNCTION OF THE BRAKE MEAN EFFECTIVE

PRESSURE

214. Where the arrangements permit a propulsion motor

to be connected to a generating plant having a continuous

rating greater than the motor rating, means shall be provided

to limit the continuous input to the motor to a value not

exceeding 5% overload in torque, based on the continuous

full-load torque for which the motor is designed.

F2. GENERATORS FOR INTEGRATED

PROPULSION PLANTS

100. Application

101. The present requirements are additional to those of

Part II, Title 11, Section 7 Chapter F of the RBNA Rules for

Steel Ships, inland and open sea navigation, and to the IMO

SOLAS convention, .Chapter II-1/D 41.

102. The generator power rating is to take into account

the total distortion of currents in the electrical system.

103. The requirements for integrated propulsion plant

generators are in the IEEE 45-2 Standard, Chapter 31,

Section 31.5.

104. AC generators are to be designed with adequate

load margin to guard against overload during rough weather

and maneuvering.

105. The generating sets shall be designed to ensure that

with any one generator or its primary source of power out of

operation, the remaining generating sets shall be capable of

providing the electrical services necessary to start the main

propulsion plant from a dead ship condition.

106. The emergency source of electrical power may be

used for the purpose of starting from a dead ship condition if

its capability either alone or combined with that of any other

source of electrical power is sufficient to provide at the same

time those services required to be supplied.

107. Where separately driven direct-current generators

are connected electrically in series, means shall be provided

to prevent reversal of the direction of rotation of any of them

on the failure of the driving power of the prime mover.

(

108. The rotor shall be equipped with a damper winding

to avoid large oscillations in frequency and load sharing for

any variation in the load.

109. The temperature of the stationary windings of AC

generators is to be monitored and the temperature displayed

on the generator control panel and/or in any other control

stations

110. Provisions are to be made to prevent circulating

currents between the shaft and the bearing of electric

generators.

200. Generator and motor excitation

201. Every exciter set is to be supplied by a separate

feeder.

202. Overload circuit-interrupting devices are not (to

be fitted in excitation circuits, except those in connection

with the protection for the propulsion generator.




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203. The excitation shall be controlled by an automatic

voltage regulator (AVR), which senses the terminal voltage

of the generator and compares it with a reference value.

a. If a propulsion system contains only one generator and

one motor and cannot be connected to another

propulsion system, more than one exciter with

controller should be provided for both motor and

generator as applicable, except for self-excited

generators, where a duplicated automatic voltage

regulator is sufficient.

204. The rotor is to be equipped with a damper winding

introducing an electromagnetic damping to the stator and

rotor dynamics.

205. Static excitation power supplies shall comply with

the requirements of IEEE Std 444-1973 to the maximum

extent practicable.

Note: A synchronous machine without damper winding is

inherently without damping and would give large

oscillations in frequency and load sharing for any variation

in the load.

206. In DC systems, arrangements for generator and

motor excitation shall be such that, if the motor excitation

circuit is opened by a switch or contactor, the generator

excitation is simultaneously interrupted or the generator

voltage is immediately reduced to zero.

)

207. Excitation circuits are to be provided with lamps,

voltmeters or other suitable means to indicate continuously

the state of the insulation under running conditions.

300. Voltage control

301. Propulsion generators shall be fitted with an

automatic voltage regulator (AVR).

a. A stand-by automatic voltage regulator shall be

provided for each type of AVR.

b. For propulsion generators, manual voltage regulation is

not permitted.

302. The stationary voltage variation on the generator

terminals shall not exceed ±2.5% of nominal voltage.

400. Overspeed

401. Overspeed protection is recommended for all prime

mover driven generators.

a. The overspeed element should be responsive to machine

speed by mechanical, or equivalent electrical

connection

b. If it is electrical, the overspeed element should not be

adversely affected by generator voltage.

500. Short circuit

501. AC generators and their excitation systems are to

be able to withstand under a steady state short-circuit a

current of three times the rated current for a period of at

least two seconds.

600. Emergency generators

601. For integrated system, emergency generator sets

must satisfy the governor conditions as per items F1.201 to

F1.203 even when:

a. their total consumer load is applied suddenly, or

b. their total consumer load is applied in steps, subject to:

- the total load is supplied within 45 seconds since

power failure on the main switchboard;

- the maximum step load is declared and

demonstrated;

- the power distribution system is designed such that

the declared maximum step loading is not

exceeded;

- the compliance of time delays and loading

sequence with the above is to be demonstrated at

ship’s trials.

F3. POWER MANAGEMENT SYSTEMS

100. Power management requirements

101. The purpose of the Power Management System

(PMS) is to ensure that there is sufficient available power

for the actual operating condition. The power management

system is to be designed to control load sharing between

generators, prevent blackouts, maintain power to the

essential service loads and maintain power to the propulsion

loads.

102. The protective equipment shall be capable of being

set to not to operate on the overloads or excess currents

likely to be experienced in a heavy seaway or when

maneuvering. Measures are to be taken to ensure that the

equipment is functioning in a reliable manner and that

satisfactory arrangements are made for regular inspections

and routine tests to ensure continuous reliable operation.

103. For the protection of the field windings and cables,

means shall be provided for limiting the voltage induced

when the field circuits are opened.

104. A computerized system shall be fitted to

automatically manage the power to keep the system

parameters inside the safety limits. The computerized

system shall manage the load distribution between

generators operating in parallel.




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105. The computerized PMS system shall be in

compliance with Part II, Title 102, Chapter A, Subchapter

A.6 of the RBNA Rules for the Construction and

Classification of Ships According to their Mission for open

sea navigation.

106. The power management computer system is to be

capable of tripping non-essential systems in case of an

overload. Essential ship service systems shall have priority

over propulsion under all conditions.

107. An audio and visual alarm shall be triggered in case

the power limitation system is activated.

108. The power management system shall ascertain that

any failure in the power supply system does not change the

rotation and direction of the propeller.

a. Where electric, pneumatic or hydraulic aid is used for

normal operation, provision shall be made such that a

failure shall not result in interruption of power to the

propeller shaft and any such device shall be capable or

purely manual operation without delay.

109. Means are to be provided to prevent the

regenerative power to cause overspeeding of the prime

mover or variations in the system voltage and frequency

which exceeds the limits in Chapter E above.

110. The power management system shall be provided

with means of monitoring voltage harmonic distortion. An

audible and visual alarm shall be triggered by an increase in

harmonic distortion in the system above the maximum

allowable levels.

111. Adequate interlocks shall be provided to prevent

damage to the plant as a result of incorrect switching such as

the opening of switches or contactors not intended to be

operated while carrying current.

F4. ALARMS AND PROTECTIONS

100. Alarm and safety system

112. Where automated or remote control systems are

installed, the requirements of Part II, Title 102, Section 5,

Chapter A4 (Chapter B4 for compact engines) of the RBNA

Rules for open sea navigation are applicable.

200. Protections and alarms

201. Safety and alarm systems are to be installed, in

accordance with the requirements of Part II, Title 102,

Section 5, Chapter A4 (Chapter B4 for compact engines) of

the RBNA Rules for open sea navigation.

202. The following alarms and protections are to be

provided, as applicable:




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TABLE T.F4.201.1 - SWITCHBOARD Switchboards: Reduction of

power/trip Alarm Protection

Under- and over-voltage, typically alarm only x

Under- and over-frequency, typically alarm only x

Earth fault, trip or alarm depending on earthing philosophy

x x x

Differential, or other fast short circuit protection x x

TABLE T.F4.201.2 - GENERATOR Generator: Reduction of


Overcurrent and short circuit x x

Earth fault x x x

Reverse power x x

Phase unbalance ,Negative phase sequence x x

Under- and overvoltage x x

Over- and under-frequency x x

Under- and over-magnetization and/or capacitive reactive power

x x

Differential protection with transformer inrush blocking

x

Synchronizing check with speed output to prime mover

x

High winding (generators over 500 kW and bearingstemperature

x x x

High coolant (air/water) temperature x x

Reduced flow of primary and secondary coolants in closed cooling systems with a heat exchanger

x x

Low lubricating oil pressure of bearings x (reduction) x

Leakage of coolant inside the enclosure with liquid-air exchan

x

Lack of coolant ) x (reduction) x

Over- and under-excitation (loss of excitation) x

Fan failure of forced ventilation or failure of cooling system

x (reduction) x

TABLE T.F4.201.3 – BUS TIE AND TRANSFER FEEDERS Bus tie and transfer feeders Reduction of


Short circuit – may be included in generator protection

x x

Earth fault x x

Load limitation x x x

Synchronizing check x

Differential protection (in ring network configurations)

x

TABLE T.F4.201.4 - TRANSFORMER Transformer Reduction of


Over current x x

Short circuit x x

Thermal overload/image x

Earth fault x

Under-voltage x x

For large transformers differential protection x

High coolant temperature x


x

TABLE T.F4.201.5 – ELECTRIC MOTOR Motor : Reduction of


Overcurrent x x

Short circuit x x

Earth fault x x

Thermal overload/image x

Negative phase sequence x

Motor start: stalling, I2t, number of starts x

Earth fault x x

Under-voltage x x




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Motor : Reduction of power/trip

Alarm Protection

High coolant (air/water) temperature x x

High winding (generators over 500 kW and bearings temperature

x x x


x x

Leakage of coolant inside the enclosure with liquid-air exchangers

x

Lack of coolant x (reduction) x

Earth fault for excitation circuits x

Low lubricating oil pressure x (reduction) x

Protection against flashover in DC propulsion motors

x


x (reduction) x

Overspeed in DC propulsion motors x

TABLE T.F4.201.6 – SEMICONDUCTOR CONVERTER Semiconductor Converter Reduction of


Over-voltage protection x (trip) x x

Over-current protection x (trip) x x

Earth fault x x

Short circuit protection x (trip) x x

Loss of cooling x (reduction) x

Over-temperature x

Loss of communication to PMS x x

Loss of motor speed feedback x x


x

Leakage of coolant inside the enclosure with liquid-air exchangers

x

Protection on filter circuits to limit disturbances due to semiconductor converters

x (trip) x

Voltage unbalance of three-phase a.c. systems supplied by semiconductor converters

x


x (reduction) x

TABLE T.F4.201.7 – POWER MANAGEMENT SYSTEM Power management system Reduction of


System limiting propulsion power x

Loss of signal x x

Failure of the Power Management System x

Load limitation of generators or inadequate available power

x (reduction) BV

x

TABLE T.F4.201.8 - NETWORK Circuit protection Reduction of


Overcurrent protection devices x

DC propulsion circuits overload relay protection (fuses are not allowable for this protection

x

Selective tripping or rapid reduction of magnetic fluxes

x (trip or reduction)

Earth leakage detection x x

Voltage unbalance of three-phase A.C. systems supplied by semiconductor frequency converters

x

Earth fault for the main propulsion circuit x (trip) x

Increase in total or individual harmonic distortion levels above maximum allowable levels

x

300. Additional requirements

301. For DC equipment operating at voltages exceeding

500 volts and for all AC equipment, both audible and visual

ground alarms shall be fitted:

a. to operate automatically on the occurrence of a ground

fault but the operation of such devices shall not

interrupt the power supply;

b. to allow for switching off the audible device, but in

such cases the visual alarm shall remain switched on

until the fault has been cleared; and




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c. where a ground connection is used for the operation of

the indicator, the arrangement shall be such that the

ground circuit is opened automatically in order to stop

the circulation of fault current

302. An audible alarm device shall be provided for

machines having enclosed-ventilating systems, arranged to

operate in the event of the temperature of the heated air

exceeding the predetermined safe value.

303. Pressure or gravity lubrication systems shall be

provided with a low oil pressure alarm and with an

alternative means of lubrication, as follows:

a. an automatic operated stand-by pump;

b. an automatic brevity supply reservoir; or

c. oil rings

F5. FAILURE MODE AND EFFECT ANALYSIS

100. FMEA

101. For the propulsion systems and electrical power

supplies in ships with class notation DEP an FMEA analysis

may be requested at RBNA’s discretion and is to address the

requirements identified in the present Rule.

12. For ships with class notation DEPR, an FMEA is

mandatory for the complete propulsion and steering systems

and their auxiliaries, to show that these requirements are

met.

CHAPTER G

DESIGN AND INSTALLATION OF THE POWER

CONSUMERS – LIGHT AND MOTORS

CHAPTER CONTENTS

G1. PROPULSION MOTORS

G2. MOTOR DRIVE FOR PROPULSION AND

THRUSTERS

G3. PROPULSION DRIVE TRANSFORMERS

G4. SWITCHCHBOARDS

G5. POD UNITS

G1. PROPULSION MOTORS

100. Application

101. The requirements for propulsion motors are those

of the IEEE 45-2002 Standard, Chapter 31, section 31.7.

102. In case the installation does not comprise self-

extinguishing materials, provisions are to be made for a fire

extinguishing system suitable for fires in electrical

equipment, for motors that are enclosed or in which the air

gap is not directly exposed.

103. Provisions shall be made for shunt resistors which

are connected across the field circuit of synchronous

propulsion motors when they are functioning as a

synchronous motor to be suitably insulated for the voltage

induced when maneuvering and shall be amply rated.

104. Provision shall be made for contactors and switches

used for reversing the rotation of the propulsion motors to

be provided with means for opening them forcibly if they

should inadvertently be left closed and they shall be so

interlocked mechanically as to prevent the circuits for ahead

and astern rotation being closed simultaneously.

G2. PROPULSION POWER CONVERSION

EQUIPMENT

100. Requirements for power converters

101. The most commonly used converters for motor

drives are:

- Voltage source inverter (VSI) type converters for AC

motors, normally asynchronous motors

- Cyclo converters (Cyclo) for AC motors, normally for

synchronous motors




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- Current source inverter type (CSI) converters for AC

motors, normally synchronous motors

- DC converters, or SCR (Silicon Controlled Rectifier)

for DC motors

102. The propulsion power conversion equipment is to

be in accordance with IEEE 45-2 chapter 31, section 31.8, or

IEC series 60146 (Semiconductor converters – General

requirements and line commutated converters) as far as

possible,

G3. PROPULSION DRIVE TRANSFORMERS

100. Requirements for propulsion transformers

101. Propulsion drive transformers are to be able to:

- Adjust the tension level between the power

distribution system and the converter;

- Reduce harmonic distortion;

- Reduce EMI noise; and

- Separate motor drive circuits from distribution

system’s grounding philosophy.

102. Propulsion transformers are to be provided with:

- Means for monitoring of the winding temperature;

- In case of cooled transformers, means to monitor

liquid temperatures;

- High temperature alarm;

- Means for monitoring cooling air temperatures for

ventilated transformers; and

- Means to regulate transformer output voltage

103. Transformer rating shall be in accordance with IEC

60726, or applicable IEEE Std C57 series standards

G4. SWITCHBOARDS

100. Application

101. This Subchapter applies to electric switchboards for

diesel electric propulsion system, integrated or not.

200. Requirements for design and installation

201. The requirements for the construction of electric

switchboards are to follow the IEEE 45-2002 standard,

chapter 8. However, for electric propulsion switchboards,

the requirements of the present Subchapter H.4 G4 apply.

202. The main bus bar of switchboards for propulsion

shall be subdivided into at least two parts connected by

circuit breakers or other approved means.

203. Alternatively, the ship may be fitted with

independent switchboard parts supplying two or more

independent networks.

204. The switchboard shall be built to tolerate failure

due to fire or flooding by water by fireproof dividers to

segregate the sections or other equivalent means.

205. The switchboards, shall be so arranged that the

electrical supply necessary for propulsion and maneuvering

will be available at all times, even after incurring any single

fault.

Note: In a two-split configuration, with equally shared

generator capacity and load on both sides, the maximum

single failure scenario will be to lose 50% of generator

capacity and loads.

206. Load shedding or equivalent arrangements shall be

provided to protect the generators against sustained

overload.

207. Switchboards which are totally enclosed are to be

provided with an adequate ventilation system, and the

exhaust piping conducted to a safe place free from

flammable gases or vapors.

208. The access doors of switchboards operating at

voltages in excess of 50 volts are to be provided with

protection from opening by unauthorized personnel.

G5. POD UNITS

100. Pod units

101. Podded propulsion systems consist of an electric

motor placed in a housing located under the hull of the

vessel.

102. The electrical motor is directly connected to one or

two propellers.

103. The pod is steerable or fixed. A steerable podded

propulsion unit constitutes both propulsion machinery and

the steering system.

104. The requirements of the IEC standards, especially

the shipbuilding related standards of the series IEC 60092,

have to be fulfilled.

105. The electric motor can be an induction

(asynchronous) motor, a synchronous motor, or a permanent

magnet motor. If the vessel is equipped with only one

podded thruster, the motor shall consist of at least two

electrically independent winding systems.




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CHAPTER H

AUXILIARY SYSTEM

CHAPTER CONTENTS

H1. REQUIREMENTS FOR AUXILIARY SYSTEMS

OF THE DIESEL ELECTRIC PROPULSION

SYSTEM

H1. REQUIREMENTS FOR AUXILIARY

SYSTEMS OF THE DIESEL ELECTRIC

PROPULSION SYSTEMS

100. Requirements for auxiliary systems

101. Where electric, pneumatic or hydraulic aid is used

for normal operation, failure of such aid shall not result in

interruption of power to the propeller shaft, and any such

device shall be capable of purely manual operation without

delay.

CHAPTER T

TEST OF ELECTRICAL INSTALLATIONS

T1. TESTS AT MANUFACTURER

T2. QUAY AND SEA TRIALS

T1. TESTS AT MANUFACTURER

100. Equipment acceptance and certification tests

101. Tests at manufacturers are to be carried out

according to the Rules for the Construction and

Classification of Steel Vessels Identified by their Missions,

for inland and open sea navigation, Part III, Title 63, Section

7, and/or applicable standards.

T2. QUAY AND SEA TRIALS

100. Tests and Trials

101. A quay and sea trials program is to be submitted to

RBNA for approval before the commencement of the tests.

102. Quay trials are to be conducted according to

manufacturers and shipyard procedures to ascertain that the

equipment is in operational order in conformity to their

function.

103. Prior to sea trial, the insulation resistance is to be

measured and recorded.

104. Full tests of the diesel electric propulsion systems

are to be carried out during sea trials, such as:

- Duration runs at full propulsion load

- Reversal from full speed ahead to full speed astern

- Maneuvering tests (zig-zag, full turns)

- Alarms, protections, safety functions

- Control modes

105. In case a FMEA has been requested, all FMEA

conditions are to be tested.

106. Other tests required to ascertain that components

and the diesel electric propulsion and power generation

plant are satisfactory and in conformity with the present

Rule requirements shall be conducted as necessary.

Rgep18en – Electric Propulsion – abdefght-00