nari pcs-985g generator relay

PCS-985G

Generator Relay

Instruction Manual

NR Electric Co., Ltd.

Preface

PCS-985G Generator Relay i

Date: 2013-6-23

Preface

Introduction

This guide and the relevant operating or service manual documentation for the equipment provide

full information on safe handling, commissioning and testing of this equipment.

Documentation for equipment ordered from NR is dispatched separately from manufactured goods

and may not be received at the same time. Therefore, this guide is provided to ensure that printed

information normally present on equipment is fully understood by the recipient.

Before carrying out any work on the equipment, the user should be familiar with the contents of

this manual, and read relevant chapter carefully.

This chapter describes the safety precautions recommended when using the equipment. Before

installing and using the equipment, this chapter must be thoroughly read and understood.

Health and Safety

The information in this chapter of the equipment documentation is intended to ensure that

equipment is properly installed and handled in order to maintain it in a safe condition.

When electrical equipment is in operation, dangerous voltages will be present in certain parts of

the equipment. Failure to observe warning notices, incorrect use, or improper use may endanger

personnel and equipment and cause personal injury or physical damage.

Before working in the terminal strip area, the equipment must be isolated.

Proper and safe operation of the equipment depends on appropriate shipping and handling,

proper storage, installation and commissioning, and on careful operation, maintenance and

servicing. For this reason, only qualified personnel may work on or operate the equipment.

Qualified personnel are individuals who:

Are familiar with the installation, commissioning, and operation of the equipment and of the

system to which it is being connected;

Are able to safely perform switching operations in accordance with accepted safety

engineering practices and are authorized to energize and de-energize equipment and to

isolate, ground, and label it;

Are trained in the care and use of safety apparatus in accordance with safety engineering

practices;

Are trained in emergency procedures (first aid).

Instructions and Warnings

The following indicators and standard definitions are used:

Preface

PCS-985G Generator Relay ii Date: 2013-6-23

DANGER!

It means that death, severe personal injury, or considerable equipment damage will occur if safety

precautions are disregarded.

WARNING!

It means that death, severe personal, or considerable equipment damage could occur if safety

precautions are disregarded.

CAUTION!

It means that light personal injury or equipment damage may occur if safety precautions are

disregarded. This particularly applies to damage to the device and to resulting damage of the

protected equipment.

WARNING!

The firmware may be upgraded to add new features or enhance/modify existing features, please

make sure that the version of this manual is compatible with the product in your hand.

WARNING!

During operation of electrical equipment, certain parts of these devices are under high voltage.

Severe personal injury or significant equipment damage could result from improper behavior.

Only qualified personnel should work on this equipment or in the vicinity of this equipment. These

personnel must be familiar with all warnings and service procedures described in this manual, as

well as safety regulations.

In particular, the general facility and safety regulations for work with high-voltage equipment must

be observed. Noncompliance may result in death, injury, or significant equipment damage.

DANGER!

Never allow the current transformer (CT) secondary circuit connected to this equipment to be

opened while the primary system is live. Opening the CT circuit will produce a dangerously high

voltage.

WARNING!

Exposed terminals

Do not touch the exposed terminals of this equipment while the power is on, as the high voltage

generated is dangerous.

Preface

PCS-985G Generator Relay iii

Date: 2013-6-23

Residual voltage

Hazardous voltage can be present in the DC circuit just after switching off the DC power supply. It

takes a few seconds for the voltage to discharge.

CAUTION!

Earth

The earthing terminal of the equipment must be securely earthed.

Operating environment

The equipment must only be used within the range of ambient environment detailed in the

specification and in an environment free of abnormal vibration.

Ratings

Before applying AC voltage and current or the DC power supply to the equipment, check that they

conform to the equipment ratings.

Printed circuit board

Do not attach and remove printed circuit boards when DC power to the equipment is on, as this

may cause the equipment to malfunction.

External circuit

When connecting the output contacts of the equipment to an external circuit, carefully check the

supply voltage used in order to prevent the connected circuit from overheating.

Connection cable

Carefully handle the connection cable without applying excessive force.

Copyright

Version: R1.00

P/N: EN_YJBH2641.0086.0001

Copyright NR 2013. All rights reserved

NR ELECTRIC CO., LTD.

69 Suyuan Avenue. Jiangning, Nanjing 211102, China

Tel: +86-25-87178185, Fax: +86-25-87178208

Website: www.nrelect.com, www.nari-relays.com

Email: [email protected]

We reserve all rights to this document and to the information contained herein. Improper use in particular reproduction and dissemination

to third parties is strictly forbidden except where expressly authorized.

The information in this manual is carefully checked periodically, and necessary corrections will be included in future editions. If

nevertheless any errors are detected, suggestions for correction or improvement are greatly appreciated.

We reserve the rights to make technical improvements without notice.

Preface

PCS-985G Generator Relay iv Date: 2013-6-23

Documentation Structure

The manual provides a functional and technical description of this relay and a comprehensive set

of instructions for the relays use and application.

All contents provided by this manual are summarized as below:

1 Introduction

Briefly introduce the application, functions and features about this relay.

2 Technical Data

Introduce the technical data about this relay, such as electrical specifications, mechanical

specifications, ambient temperature and humidity range, communication port parameters, type

tests, setting ranges and accuracy limits and the certifications that our products have passed.

3 Operation Theory

Introduce a comprehensive and detailed functional description of all protective elements.

4 Supervision

Introduce the automatic self-supervision function of this relay.

5 Management

Introduce the displayed measurement and recording in the relay.

6 Hardware

Introduce the main function carried out by each plug-in module of this relay and providing the

definition of pins of each plug-in module.

7 Settings

List all the settings and some notes about the setting application.

8 Human Machine Interface

Introduce the hardware of the human machine interface (HMI) module and a detailed guide for the

user how to use this relay through HMI. It also lists all the information which can be view through

HMI, such as settings, measurements, all kinds of reports etc.

9 Communication

Introduce the communication port and protocol which this relay can support, IEC60970-5-103,

IEC61850 and DNP3.0 protocols are introduced in details.

10 Installation

Introduce the recommendations on unpacking, handling, inspection and storage of this relay. A

guide to the mechanical and electrical installation of this relay is also provided, incorporating

earthing recommendations. A typical wiring connection to this relay is indicated.

Preface

PCS-985G Generator Relay v

Date: 2013-6-23

11 Commissioning

Introduce how to commission this relay, comprising checks on the calibration and functionality of

this relay.

12 Maintenance

A general maintenance policy for this relay is outlined.

13 Decommissioning and Disposal

A general decommissioning and disposal policy for this relay is outlined.

14 Manual Version History

List the instruction manual version and the modification history records.

Typographic and Graphical Conventions

Deviations may be permitted in drawings and tables when the type of designator can be obviously

derived from the illustration.

The following symbols are used in drawings:

&

AND gate

1

OR gate

Comparator

BI

Binary signal via opto-coupler

SET I>

Input signal from comparator with setting

EN

Input signal of logic setting for function enabling

SIG

Input of binary signal except those signals via opto-coupler

OTH

Input of other signal

XXX

Output signal

Preface

PCS-985G Generator Relay vi Date: 2013-6-23

t

t

Timer

Timer (optional definite-time or inverse-time characteristic)

10ms 0ms

Timer [delay pickup (10ms), delay dropoff (0ms), non-settable]

[t1] 0ms

Timer (t1: delay pickup, settable)

0ms [t2]

Timer (t2: delay dropoff, settable)

[t1] [t2]

Timer (t1: delay pickup, t2: delay dropoff, settable)

IDMT

Timer (inverse-time characteristic)

*

*

Instrument current transformer

Instrument voltage transformer

Symbol Corresponding Relationship

Basic Example

A, B, C L1, L2, L3 Ia, Ib, Ic, I0 IL1, IL2, IL3, IN

AN, BN, CN L1N, L2N, L3N Ua, Ub, Uc VL1, VL2, VL3

ABC L123 Uab, Ubc, Uca VL12, VL23, VL31

U (voltage) V U0, U1, U2 VN, V1, V2

1 Introduction

PCS-985G Generator Relay 1-a

Date: 2013-06-23

1 Introduction

Table of Contents

1 Introduction ..................................................................................... 1-a

1.1 Application ....................................................................................................... 1-1

1.2 Function ........................................................................................................... 1-1

1.3 Features ........................................................................................................... 1-3

1.4 Order Information............................................................................................ 1-7

List of Tables

Table 1.2-1 Function configuration of generator ..................................................................... 1-1

Table 1.2-2 Function configuration of excitation transformer/exciter ................................... 1-2

Table 1.2-3 Mechanical function configuration ........................................................................ 1-2

1 Introduction

PCS-985G Generator Relay 1-1

Date: 2013-06-23

1.1 Application

PCS-985G can be applied for large-scale turbo-dynamo, gas-turbine generator and nuclear power

generator with different connection modes.

PCS-985G provides complete electric quantity protection of a generator and an exciter or

excitation transformer. It also supports ECT/EVT and meets the requirements of power plant

automation.

For a large-scale generator, two sets of PCS-985G can be used and then main protection,

abnormal operation condition protection and backup protection can be duplicated. Control circuit

and mechanical protection are installed on a separate panel. Two sets of PCS-985G use different

CT groups and main and backup protection in one PCS-985G share one CT group. The outputs

correspond to various trip coils.

1.2 Function

PCS-985G takes fully into account maximum configuration of large-scale generator, and suits the

generator with capacity of 100MW or above.

1.2.1 Protection Function

PCS-985G can select to configure the following protection functions, and means that it is an

abnormality alarm function.

Table 1.2-1 Function configuration of generator

No. Function Stage Delay ANSI

1 Differential protection 87G

2 DPFC differential protection 87G

3 Transverse differential protection 2 87G

4 Longitudinal residual overvoltage protection for inter-turn fault 1 1 59N/60

5 DPFC directional protection for inter-turn fault 1 1 67

6 Calculated longitudinal residual overvoltage protection for inter-turn

fault 1 1

7 Voltage controlled overcurrent protection 2 1 50

8 Phase-to-phase impedance protection 2 1 21G

9 Fundamental residual voltage protection for stator earth fault 2 1 64S

10 Third harmonic overvoltage ratio protection for stator earth fault 1 1 64S

11 Third harmonic overvoltage differential protection for stator earth fault 1 1 64S

12 stator earth-fault protection with voltage injection 2 1 64R

13 Rotor one-point earth-fault protection 2 1 64R1

14 Rotor two-point earth-fault protection 1 1 64R2

15 Definite-time stator overload protection 2 1 50S

16 Inverse-time stator overload protection 51S

17 Definite-time negative-sequence overload protection 2 1 50Q

18 Inverse-time negative-sequence overload protection 51Q

1 Introduction

PCS-985G Generator Relay 1-2 Date: 2013-06-23

19 Loss-of-excitation protection 3 1 40

20 Out-of-step protection 2 1 78

21 Overvoltage protection 2 1 59

22 Undervoltage protection 1 1

23 Definite-time over-excitation protection 2 1 24

24 Inverse-time over-excitation protection 24

25 Reverse-power protection 2 1 32R

26 Low-power protection 1 1 37G

27 Sequential tripping reverse-power protection 1 1 32R

28 Underfrequency protection 3 1 81U

29 Overfrequency protection 2 1 81O

30 Startup/shutdown protection of differential current 1 1

31 Startup/shutdown protection of residual voltage 1 1

32 Low-frequency overcurrent protection 1 1 50

33 Inadvertent energization protection 1 1 50/27

34 Breaker failure protection 1 2 50BF

35 Voltage balance function 60

36 VT circuit supervision VTS

37 CT circuit supervision CTS

Note!

Rotor earth-fault protection can select voltage switchover principle or external voltage

injection principle.

Table 1.2-2 Function configuration of excitation transformer/exciter


1 Differential protection 87ET

2 Overcurrent protection 2 1 50

3 Definite-time overload protection 1 1 50

4 Inverse-time overload protection 51

Table 1.2-3 Mechanical function configuration


1 Mechanical protection 1 1 1








1 Introduction


Date: 2013-06-23

Note!

The name of mechanical protection 1~8 can be modified.

1.2.2 Configuration Explanation

1.2.2.1 Differential Protection

1. For generator with the capacity of 300MW or above, panel A and B are both equipped with

generator differential protection.

2. For generator differential protection, there are two kinds of percentage differential protection:

variable slope percentage differential protection and DPFC percentage differential protection.

1.2.2.2 Backup Protection

1. Panel A and B are equipped with complete set of backup protection of generator and

excitation transformer/exciter. Different CTs are used for them.

2. As to rotor earth-fault protection, two sets of such protection cannot work simultaneously

otherwise influence between them will appear. Only one set of rotor earth-fault protection can

be enabled during operation. If other set will be put into operation sometimes, this set shall be

quitted firstly.

1.2.2.3 Current Transformer

1. Panels A and B adopt different CT.

2. Main protection and backup protection share one group of CT.

3. Generator reverse power protection can share one group of generator terminal CT with

generator differential protection, or adopt independent measurement CT.

1.2.2.4 Voltage Transformer

1. Panel A and B shall adopt different VT or its different windings if possible.

2. For generator inter-turn protection, in order to prevent undesired operation due to VT circuit

failure at HV side used dedicatedly for this protection, one set of protection shall adopt two

groups of VT. However, if it is considered to adopt only independent VT windings, too much

VT will be installed at generator terminal and it is not reasonable. So it is recommended to

equip three windings of VT there, namely VT1, VT2 and VT3. Panel A adopts voltage from

VT1 and VT3 while panel B VT2 and VT3. During normal operation, panel A adopts VT1 and

panel B adopts VT2 while VT3 is backup to both of them. If circuit of VT1 or VT2 fails, VT3 will

be switched on automatically by software.

3. For residual voltage, there are two windings adopted by two sets of protection equipments

simultaneously in general.

1.3 Features

High-performance general-purpose hardware and real-time calculations

1 Introduction


Hardware structure of 32-bit microprocessorsdual DSP is adopted. A number of processors

operate in parallel. 32-bit microprocessors provide functions of HMI, communication, and printing,

etc. The two DSPs provide protection operations and output logic. High performance hardware

ensures real-time calculation for all relays in each sampling interval of this relay. This relay adopts

32-bit high performance CPUs and DSPs, internal high-speed bus, and intelligent I/O. Both

hardware and software adopt modular design, which can be flexibly configured. Features include

versatility, easy expansion, and easy maintenance.

Independent fault detector elements

The output mode of fault detector AND protection operation eliminates the possibility of

malfunction and misjudgment caused by hardware fault of the device.

Strong EM compatibility

Integral panel and fully enclosed chassis are adopted. Strong electricity and weak electricity are

strictly separated. Traditional rear board wiring mode is not used. At the same time, measures

against interference are taken in software design, greatly improving the immunity to disturbances.

EM radiation to outside satisfies relevant standards.

Modular programs

Modular programs allow flexible protection configuration and easy functional adjustment.

Variable slope percentage differential protection

Variable slope percentage characteristic is adopted for differential protection. Pickup slope and

maximum slope should be reasonably set, so that high sensitivity can be gained during internal

fault and transient unbalance current can be avoided during external fault. In order to prevent

undesired operation of differential protection due to CT saturation, measures to discriminate CT

saturation are provided for phase current at each side.

DPFC percentage differential protection

DPFC percentage differential protection reflects only deviation components of differential current

and restraint current and is not effected by load current. It can detect light fault within generator.

Besides, it is insensitive to CT saturation since its restraint coefficient is set comparatively high.

Detect CT Saturation by asynchronous method

According to relation between DPFC restraint current and DPFC differential current of differential

protection, external or internal fault can be discriminated correctly. For external fault, waveform

discrimination of phase current and differential current is adopted. Undesired operation will not

occur if CT correct transfer time from primary to secondary side is not less than 5ms. As to internal

fault, the device will operate quickly.

High-sensitive transverse differential protection

By adopting frequency tracking, digital filter and Fourier transformation, the filtration ratio of third

harmonic component can reach more than 100. These entire countermeasure guarantees the

reliability of the protection in all occasions as mentioned as below:

1 Introduction


Date: 2013-06-23

The transverse differential protection can get reliable restraint effect because the faulty phase

current increases greatly while transverse differential current increases less in external fault

situation.

The protection has very high operation sensitivity because transverse differential current

increases comparatively large whereas phase current change not too observably in slightly

inter-turn fault situation.

The high-setting stage of transverse differential protection will operate quickly and reliably when

severe inter-turn fault occurs in stator winding.

In case of phase-to-phase fault of stator winding, not only transverse differential current but also

phase current increase greatly, therefore just low percentage restraint by phase current

guarantees the reliable operation of transverse differential protection against the fault.

As for unbalanced transverse differential current increasing during normal operation condition,

transverse differential protection uses float threshold to avoid undesired operation.

Percentage restraint inter-turn protection


harmonic component can reach more than 100. Calculated longitudinal residual overvoltage

protection is adopted in PCS-985G, which is the new criteria of generator inter-turn protection and

does not need the special VT for the protection.

Stator earth-fault protection


harmonic component can reach more than 100.

The sensitive stage of fundamental residual voltage protection operates and issues trip command

only if the dual criterias of residual voltages of generator terminal and neutral point are met at the

same time.

The ratio settings of third harmonic of generator terminal to that of neutral point used in third

harmonic ratio criteria will automatically suit to the change of ratio fore-and-aft incorporating in

power network third harmonic voltage of the plant unit. This automation adjustment function

ensures the correctness of signals generated and issued by the third harmonic voltage criteria

even during incorporation or isolation course of generator.

The ratio and phase-angle difference of third harmonic voltage of generator terminal to that of

neutral point keeps almost stable when the generator is in normal operation condition; also it is a

slow developing course. Through real time adjustment of coefficient of amplitude value and phase,

PCS-985 makes differential voltage between generator terminal and neutral point as zero in

normal operation condition. When stator earth fault occurs, the criteria tend to operate reliably and

sensitively.

Stator earth-fault protection with external voltage injection principle

The protection adopts digital technology to calculate earth fault resistance accurately.

1 Introduction


Settings configured two stage are provided. One stage operates to alarm, and the other stage

operates to trip.

The residual current protection is free from impact of 20Hz power, which provides mainly

protection for comparatively severe stator earth fault.

The protection is adaptive for various operation conditions, such as stillness, no-load, shutdown,

startup and connected to power grid.

Sampling-switch type rotor earth-fault protection

DC current is input by high-performance isolated amplifier. Via switching two different electronic

switches, PCS-985 solves four different ground-loop equations to compute rotor winding voltage,

rotor ground resistance and earthing position on real time and display these information on LCD.

Rotor earth-fault with external voltage injection principle

Injecting a low-frequency square wave between positive terminal and negative terminal of rotor

windings or between one terminal of rotor windings and axis, the device acquires leakage current

of rotor, and calculates insulation resistance between rotor windings and ground in real-time. The

injected square wave voltage is generated by the device. The protection reflects the insulation

reduction between rotor windings and axis.

The calculation to rotor earth resistance is unrelated to fault location, and no dead zone.

The calculation accuracy of rotor earth resistance is high and is not affected by the capacitance

between rotor windings and ground.

The calculation to rotor earth resistance is unrelated to excitation voltage. It can still supervise

insulation situation of rotor windings when no excitation voltage is supplied.

It can be adaptive to various lead-out modes of rotor windings, and both single-end injection and

double-ends injection can be selected. The fault location can be measured if selecting

double-ends injection.

Loss-of-excitation protection

Loss-of-excitation protection adopts optimizing protection scheme in which stator impedance

criteria, reactive power criteria, rotor voltage criteria and busbar voltage criteria, could be

optionally combined to meet various demands of different generator units.

Out-of-step protection

Out-of-step protection adopts three-impedance element (gains from positive-sequence current

and positive sequence voltage of generator) to distinguish out-of-step from steady oscillation.

More than that, the protection can accurately locate the position of oscillation center and record

oscillation slid numbers of external and internal oscillation respectively in real-time.

VT circuit failure supervision

Two groups of VT inputs are equipped at generator terminal. If one group fails, the device will

issue alarm and switch over to the healthy one automatically. It doesnt need to block protection

1 Introduction


Date: 2013-06-23

element relevant to voltage. Based on percentage restraint characteristic, it can discriminate that

neutral point of VT circuit fails.

CT circuit failure supervision

Reliable blocking function when CT circuit failure can prevent the device from undesired operation

due to CT circuit failure or AC sampled circuit failure.

Powerful communication function

Flexible communication mode is provided. 2 independent Ethernet interfaces and 2 independent

RS-485 communication interfaces are provided. Power industry communication standard

IEC60870-5-103, Modbus protocol and new generation substation communication standard

IEC61850 are supported.

Complete event recording function

64 faults and operation sequence, 64 fault waveforms, results of 256 self-supervision reports, and

1024 binary signal change reports can be recorded.

Auxiliary PC software

PC software allows easy application of this device.

1.4 Order Information

CT secondary rated value: 1A or 5A

DC power supply for device: 110/125V, 220/250V

DC power supply for binary input: 110/125V, 220V

1 Introduction


2 Technical Data


Date: 2013-06-24

2 Technical Data

Table of Contents

2 Technical Data ................................................................................. 2-a

2.1 Electrical Specifications ................................................................................. 2-1

2.1.1 AC Current Input .................................................................................................................. 2-1

2.1.2 AC Voltage Input .................................................................................................................. 2-1

2.1.3 Power Supply ....................................................................................................................... 2-1

2.1.4 Binary Input .......................................................................................................................... 2-1

2.1.5 Binary Output ....................................................................................................................... 2-2

2.2 Mechanical Specifications ............................................................................. 2-2

2.3 Ambient Temperature and Humidity Range .................................................. 2-2

2.4 Communication Port ....................................................................................... 2-3

2.4.1 EIA-485 Port ........................................................................................................................ 2-3

2.4.2 Ethernet Port ........................................................................................................................ 2-3

2.4.3 Optical Fibre Port ................................................................................................................. 2-3

2.4.4 Print Port .............................................................................................................................. 2-4

2.4.5 Clock Synchronization Port ................................................................................................. 2-4

2.5 Type Tests ........................................................................................................ 2-4

2.5.1 Environmental Tests ............................................................................................................ 2-4

2.5.2 Mechanical Tests ................................................................................................................. 2-4

2.5.3 Electrical Tests ..................................................................................................................... 2-5

2.5.4 Electromagnetic Compatibility ............................................................................................. 2-5

2.6 Certifications ................................................................................................... 2-6

2.7 Protective Functions ....................................................................................... 2-6

2.7.1 Generator/ Excitor Differential Protection ............................................................................ 2-6

2.7.2 Excitation Transformer Differential Protection ..................................................................... 2-7

2.7.3 Generator Transverse Differential Protection ...................................................................... 2-7

2 Technical Data

PCS-985G Generator Relay 2-b

Date: 2013-06-24

2.7.4 Generator Longitudinal Residual Overvoltage Protection ................................................... 2-7

2.7.5 Generator Stator Earth-fault Protection ............................................................................... 2-7

2.7.6 Stator Earth-fault Protection with External Inject Principle .................................................. 2-8

2.7.7 Generator Rotor Earth-fault Protection ............................................................................... 2-8

2.7.8 Generator Stator Overload Protection ................................................................................. 2-8

2.7.9 Generator Negative-sequence Overload Protection ........................................................... 2-8

2.7.10 Excitation Windings Overload Protection .......................................................................... 2-9

2.7.11 Generator Loss-of-excitation Protection ............................................................................ 2-9

2.7.12 Generator Out-of-step Protection ...................................................................................... 2-9

2.7.13 Generator Voltage Abnormality Protection ........................................................................ 2-9

2.7.14 Generator Over-excitation Protection .............................................................................. 2-10

2.7.15 Generator Power Protection ............................................................................................ 2-10

2.7.16 Generator Frequency Protection ..................................................................................... 2-10

2.7.17 Generator Inadvertent Energization Protection ............................................................... 2-10

2.7.18 Generator Startup/shutdown Protection ........................................................................... 2-11

2.7.19 Low-impedance Protection ............................................................................................... 2-11

2.7.20 Voltage Controlled Overcurrent Protection ....................................................................... 2-11

2.7.21 Mechanical Protection ...................................................................................................... 2-11

2.7.22 Breaker Failure Protection at Generator Terminal............................................................ 2-11

2.8 Metering Scope and Accuracy ..................................................................... 2-12

2.9 Management Functions ................................................................................ 2-12

2.9.1 Clock Performance ............................................................................................................ 2-12

2.9.2 Fault and Disturbance Recording ...................................................................................... 2-12

2.9.3 Binary Input Signal............................................................................................................. 2-12

2 Technical Data


Date: 2013-06-24

2.1 Electrical Specifications

2.1.1 AC Current Input

Standard IEC 60255-27:2005

Phase rotation ABC

Nominal frequency (fn) 505Hz, 605Hz

Rated Current (In) 1A 5A

Linear to 0.05In~40In

Thermal withstand

-continuously

-for 10s

-for 1s

-for half a cycle

4In

30In

100In

250In

Burden < 0.15VA/phase @In < 0.25VA/phase @In

Accuracy 0.5%In

2.1.2 AC Voltage Input

Standard IEC 60255-6, IEC60288

Phase rotation ABC

Nominal frequency (fn) 505Hz, 605Hz

Rated Voltage (Un) 50~120V 100~220Vbroken-delta voltage

Linear to 1~170V 2V~233V

Thermal withstand

-continuously

-10s

-1s

200V

260V

300V

220V

380V

420V

Burden at rated < 0.20VA/phase @Un < 0.80VA/phase @Un

Accuracy 0.5%Un

2.1.3 Power Supply


Rated Voltage 110Vdc/125Vdc, 220Vdc/250Vdc

Operating Range 80%~120% of rated voltage

Permissible AC ripple voltage 15% of the nominal auxiliary voltage

Burden

Quiescent condition

Operating condition

2 Technical Data


Date: 2013-06-24

Dropoff voltage

2 Technical Data


Date: 2013-06-24

Pollution degree 2

Altitude

2 Technical Data


Date: 2013-06-24

2.4.3.3 For Pilot Channel

Characteristic Glass optical fiber

Connector type FC

Fibre type Single mode

Transmission distance

2 Technical Data


Date: 2013-06-24

2.5.3 Electrical Tests


Dielectric tests Test voltage 2kV, 50Hz, 1min


Impulse voltage tests Test voltage 5kV

Overvoltage category

Insulation resistance

measurements Isolation resistance >100M@500VDC

2.5.4 Electromagnetic Compatibility

1MHz burst disturbance test

IEC 60255-22-1:2007

Common mode: class III 2.5kV

Differential mode: class III 1.0kV

Electrostatic discharge test

IEC60255-22-2:2008 class IV

For contact discharge: 8kV

For air discharge: 15kV

Radio frequency interference tests

IEC 60255-22-3:2007 class III

Frequency sweep

Radiated amplitude-modulated

10V/m (rms), f=80~1000MHz

Spot frequency

Radiated amplitude-modulated

10V/m (rms), f=80MHz/160MHz/450MHz/900MHz

Radiated pulse-modulated

10V/m (rms), f=900MHz

Fast transient disturbance tests

IEC 60255-22-4:2008

Power supply, I/O, Earth: class IV, 4kV, 2.5kHz, 5/50ns

Communication terminals: class IV, 2kV, 5kHz, 5/50ns

Surge immunity test

IEC 60255-22-5:2008

Power supply, AC input, I/O port: class IV, 1.2/50us

Common mode: 4kV

Differential mode: 2kV

Conducted RF Electromagnetic

Disturbance

IEC 60255-22-6:2001

Power supply, AC, I/O, Comm. Terminal: Class III, 10Vrms, 150

kHz~80MHz

Power Frequency Magnetic Field

Immunity

IEC 61000-4-8:2001

class V, 100A/m for 1min, 1000A/m for 3s

Pulse Magnetic Field Immunity IEC 61000-4-9:2001

class V, 6.4/16s, 1000A/m for 3s

Damped oscillatory magnetic field

immunity

IEC 61000-4-10:2001

class V, 100kHz & 1MHz100A/m

2 Technical Data


Date: 2013-06-24

Auxiliary power supply performance

- Voltage dips

-Voltage short interruptions

IEC60255-11: 2008

Up to 500ms for dips to 40% of rated voltage without reset

100ms for interruption without rebooting

2.6 Certifications

ISO9001:2008

ISO14001:2004

OHSAS18001:2007

ISO10012:2003

CMMI L4

EMC: 2004/108/EC, EN50263:1999

Products safety(PS): 2006/95/EC, EN61010-1:2001

2.7 Protective Functions

Note!

Ie is secondary rated current of generator

In is secondary rated current of CT

Un is secondary rated voltage of VT

Pn is rated active power of generator

2.7.1 Generator/ Exciter Differential Protection

Pickup setting range of percentage differential

element 0.1Ie~1.5Ie

Setting accuracy 5% or 0.01In whichever is greater

Setting range of unrestrained instantaneous

differential element 2Ie~14Ie

Setting accuracy 2.5%

Setting range of first slope of percentage differential

element 0~0.50

Setting range of maximum slope of percentage

differential element 0.30~0.80

Operation time of percentage differential protection 25ms (2 times pickup current settings)

Operation time of unrestrained instantaneous

differential protection 20ms (1.5 times pickup current settings)

2 Technical Data


Date: 2013-06-24

2.7.2 Excitation Transformer Differential Protection

Pickup setting range of percentage differential

element 0.1Ie~1.5Ie


Setting range of unrestrained instantaneous

differential element 2Ie~14Ie

Setting accuracy 2.5%

Setting range of first slope of percentage differential

element 0~0.50

Setting range of maximum slope of percentage

differential element 0.50~0.80

Secondary harmonic restraint coefficient 0.10~0.35

Operation time of percentage differential protection 35ms(2 times pickup current settings)

Operation time of unrestrained instantaneous

differential protection 25ms(1.5 times pickup current settings)

2.7.3 Generator Transverse Differential Protection

Setting range of transverse differential element 0.1ln~10ln

High setting range of transverse differential element 0.1ln~10ln

Setting accuracy 2.5% or 0.01In whichever is greater

Time delay of transverse differential element

(one-point earth) 0.1~10s

Operating time 35ms (1.5 times pickup current settings)

2.7.4 Generator Longitudinal Residual Overvoltage Protection

Setting range of longitudinal residual voltage element 1~10V

Setting accuracy 2.5% or 0.05V whichever is greater

Setting accuracy of calculated longitudinal residual

voltage element 2.5% or 0.05V whichever is greater

Time delay of longitudinal residual voltage element 0.1~10s

Setting accuracy 1%Setting + 40ms

2.7.5 Generator Stator Earth-fault Protection

Setting range of residual voltage blocking element 1~100V

Setting range of residual voltage element 0.1~50V

High setting range of residual voltage element 0.1~50V


Setting range of third harmonic voltage ratio element 0.5~10

Setting range of third harmonic voltage differential

element 0.05~2.0

Setting accuracy 5%

Time delay 0.1~10s

2 Technical Data


Date: 2013-06-24


2.7.6 Stator Earth-fault Protection with External Inject Principle

Resistance setting range 0.1~30k

Setting accuracy 5%

Residual current setting range 0.02~1.50A

Setting accuracy 5% or 0.001A whichever is greater

Time delay 0.1~10s


2.7.7 Generator Rotor Earth-fault Protection

Resistance setting range of one-point earth 0.1~100k

Setting accuracy 10% or 0.5k whichever is greater

negative-sequence voltage setting range of 2nd

harmonic 0.1~10V

Setting range of switchover cycle 0.5~10s

Time delay 0.1~10s

Setting accuracy 1%Setting + 1s

2.7.8 Generator Stator Overload Protection

Definite-time current setting range 0.1In~10In


Inverse-time pickup current setting range 0.1In~20In


Time delay 0.1 ~10s

Setting accuracy 1%Seting + 40ms

Setting range of thermal capacity of stator windings 1~100

Setting range of heat emission factor 1.02~2.0

2.7.9 Generator Negative-sequence Overload Protection

Definite-time negative-sequence current setting range 0.1In~4In


Time delay 0.1~10s


Inverse-time negative-sequence pickup current

setting range 0.05In~1In


Setting range of rotor heat constant 1~100

Setting range of continuous tolerable

negative-sequence current 0.05ln~1ln

2 Technical Data


Date: 2013-06-24

2.7.10 Excitation Windings Overload Protection

Definite-time current setting range 0.1ln~20ln

Inverse-time pickup current setting range 0.05ln~10ln


Time delay 0.1~25s


Setting range of thermal capacity factor 1~100

Setting range of reference current 0.1ln~10ln

2.7.11 Generator Loss-of-excitation Protection

Impedance setting range (Z1) 0.1 ~ 200

Impedance setting range (Z2) 0.1 ~ 200

Setting accuracy 2.5% or 0.1 whichever is greater

Reverse reactive power setting range 0 ~ 50.00%Pn

Setting accuracy 1% or 0.002Pn whichever is greater

Low-voltage setting range of rotor 1 ~ 500V

No-load voltage setting range of rotor 1 ~ 500V

Low-voltage setting range of bus or generator terminal 0.1 ~ 100V


Setting range of rotor low-voltage factor 0 ~ 10

Time delay of stage 1 and stage 2 0.1 ~ 10s

Time delay of stage 3 0.1 ~ 3000s


2.7.12 Generator Out-of-step Protection

Impedance setting A range 0 ~ 100

Impedance setting B range 0 ~ 100

Impedance setting C range 0 ~ 100

Setting accuracy 2.5% or 0.1whichever is greater

Setting range of sensitive angle 0 ~ 90

Setting range of lens inner angle lens 0 ~ 150

Setting accuracy 3

Setting range of pole slipping number 1 ~ 1000

Setting range of permitted tripping current 0.1ln ~ 20ln


2.7.13 Generator Voltage Abnormality Protection

Vero-voltage setting range 0.1 ~ 200V

Under-voltage setting range 0.1 ~ 100V


Time delay 0 ~ 10s


2 Technical Data


Date: 2013-06-24

2.7.14 Generator Over-excitation Protection

Definite time V/F setting range 1.0 ~ 2.0 pu


Definite time delay for tripping 0.1 ~ 3000.0s

Definite time delay for alarm 0.1 ~ 25s


Inverse time V/F setting range 1.0 ~ 2.0 pu

Inverse time delay for tripping 0.1 ~ 3000.0s

2.7.15 Generator Power Protection

Setting range of reverse power element 0.5 ~ 50%Pn

Setting range of reverse power sequential tripping

element 0.5 ~ 10%Pn

Setting range of under-power element 0.5 ~ 10%Pn

Setting accuracy 10% or 0.002Pn whichever is greater

Time delay of reverse power element 0.1 ~ 3000s

Time delay of reverse power sequential tripping

element 0.01~10s

Time delay of under-power element 0.01~10s


2.7.16 Generator Frequency Protection

Setting range of underfrequency protection (stage

1~3) 0.90~1.02fn

Setting range of overfrequency protection (stage 1-2) 1.00~1.20fn

Setting accuracy 0.02Hz

Time delay of underfrequency protection (stage 1~2) 0.1 ~ 300min

Time delay of underfrequency protection (stage 3) 0.1 ~ 100s

Time delay of overfrequency protection (stage 1) 0.1 ~ 100min

Time delay of overfrequency protection (stage 2) 0.1 ~ 100s


2.7.17 Generator Inadvertent Energization Protection

Current setting range of inadvertent energization

protection 0.1ln ~ 10ln


Undervoltage setting range of inadvertent

energization protection 6~80V


Blocking frequency setting range 0.80~1.00fn

Time delay of inadvertent energization protection 0.01 ~ 1.0s


2 Technical Data


Date: 2013-06-24

2.7.18 Generator Startup/shutdown Protection

Blocking frequency setting range 0.80~1.00fn

Differential current setting range 0.2le~10Ie


Overcurrent setting range under low-frequency

condition 0.1ln ~ 20ln


Residual voltage setting range 5 ~ 25V

Setting accuracy 5% or 0.02Un whichever is greater

Time delay 0 ~ 10s


setting range

2.7.19 Low-impedance Protection

Forward impedance setting range 0.1 ~ 100

Reverse impedance setting range 0.1 ~ 100


Time delay 0.1 ~ 10s


2.7.20 Voltage Controlled Overcurrent Protection

Negative-sequence voltage setting range 1 ~ 20V

Low voltage setting range 10 ~ 100V


Current setting range 0.1ln ~ 20ln


Time delay 0 ~ 10s


2.7.21 Mechanical Protection

Time delay 0.1 ~ 10s


2.7.22 Breaker Failure Protection at Generator Terminal

Phase current setting range 0.1ln ~ 4ln

Negative-sequence current setting range 0.1ln ~ 4ln


Time delay 0.1~ 10s

Setting accuracy 1% + 40ms

2 Technical Data


Date: 2013-06-24

2.8 Metering Scope and Accuracy

Metering Item Range Accuracy

Phase range 0 ~ 360 0.5% or 1

Frequency 35.00Hz ~ 70.00Hz 0.02Hz

Currents from dedicated metering current transformers

Current 0.05 ~ 1.40In 0.2% of rating

Active power (W) 0.05 ~ 1.20Un, 0.05 ~ 1.40In 1.0% of rating at unity power factor

Currents from protection measurement current transformers

Current 0.05 ~ 1.40In 2.0% of rating

Voltage 0.05 ~ 1.20Un 1.0% of rating

Active power (W) 0.05 ~ 1.20Un, 0.05 ~ 1.40In 3.0% of rating at unity power factor

2.9 Management Functions

2.9.1 Clock Performance

Real time clock accuracy 3s/day

Accuracy of GPS synchronization 1ms

External time synchronization IRIG-B (200-98), PPS, IEEE1588 or SNTP protocol

2.9.2 Fault and Disturbance Recording

Magnitude and relative phases 2.5% of applied quantities

Maximum duration 2048 sampled points (24 sampled points per cycle)

Recording position 3 cycles before pickup of trigger element

2.9.3 Binary Input Signal

Resolution of binary input signal 1ms

Binary input mode Potential-free contact

Resolution of SOE 2ms

3 Operation Theory


Date: 2013-06-28

3 Operation Theory

Table of Contents

3 Operation Theory ............................................................................ 3-a

3.1 Overview .......................................................................................................... 3-1

3.2 Fault Detector (FD) .......................................................................................... 3-1

3.2.1 Differential Protection of Generator ..................................................................................... 3-2

3.2.2 Inter-turn Protection of Generator ....................................................................................... 3-2

3.2.3 Stator Earth-fault Protection of Generator ........................................................................... 3-2

3.2.4 Stator Earth-fault Protection with Voltage Injection of Generator ........................................ 3-2

3.2.5 Rotor Earth-fault Protection of Generator ........................................................................... 3-2

3.2.6 Stator Overload Protection of Generator ............................................................................. 3-3

3.2.7 Negative-sequence Overload Protection of Generator ....................................................... 3-3

3.2.8 Loss-of-excitation Protection of Generator .......................................................................... 3-3

3.2.9 Out-of-step Protection of Generator .................................................................................... 3-3

3.2.10 Voltage Protection of Generator ........................................................................................ 3-3

3.2.11 Over-excitation Protection of Generator ............................................................................ 3-3

3.2.12 Power Protection of Generator .......................................................................................... 3-4

3.2.13 Frequency Protection of Generator ................................................................................... 3-4

3.2.14 Inadvertent Energization Protection of Generator ............................................................. 3-4

3.2.15 Startup/shutdown Protection of Generator ........................................................................ 3-4

3.2.16 Differential Protection of Excitation Transformer/Exciter ................................................... 3-4

3.2.17 Overcurrent Protection/Overload Protection of Excitation Transformer/Exciter................ 3-5

3.2.18 Breaker Failure Protection at Generator Terminal............................................................. 3-5

3.2.19 Mechanical Protection ....................................................................................................... 3-5

3.3 Differential Protection of Excitation Transformer/Exciter............................ 3-5

3.3.1 Operation Characteristic ...................................................................................................... 3-5

3.3.2 Inrush Current Detection Element ....................................................................................... 3-7

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3.3.3 CT Saturation Detection Element ........................................................................................ 3-8

3.3.4 High-setting Percentage Differential Protection Element (HSDP) ...................................... 3-8

3.3.5 Unrestrained Instantaneous Differential Protection Element (UIDP) .................................. 3-9

3.3.6 Differential Current Abnormality Alarm and CT Circuit Failure Blocking ............................. 3-9

3.3.7 Overexcitation Detection Element ..................................................................................... 3-10

3.3.8 Logic Scheme ..................................................................................................................... 3-11

3.4 Differential Protection of Generator ............................................................ 3-12

3.4.1 Percentage Differential Protection (SPDP) ....................................................................... 3-12

3.4.2 High Performance Blocking Technique in Case of CT Saturation .................................... 3-13

3.4.3 High-setting Percentage Differential Protection (HSDP) ................................................... 3-14

3.4.4 Unrestrained Instantaneous Differential Protection (UIDP) .............................................. 3-14

3.4.5 Differential Current Abnormality Alarm and CT Circuit Failure Blocking ........................... 3-14

3.4.6 Logic Scheme .................................................................................................................... 3-15

3.5 DPFC Differential Protection ........................................................................ 3-15

3.5.1 Operation Characteristic .................................................................................................... 3-16

3.5.2 Differential Current Abnormality Alarm and CT Circuit Failure Blocking ........................... 3-17

3.5.3 Logic Scheme .................................................................................................................... 3-17

3.6 Generator Inter-turn Protection ................................................................... 3-18

3.6.1 High-sensitive Transverse Differential Protection ............................................................. 3-18

3.6.2 Longitudinal Residual Voltage Protection .......................................................................... 3-20

3.6.3 VT2 Circuit Failure Alarm and Blocking ............................................................................. 3-20

3.6.4 DPFC Inter-turn Protection ................................................................................................ 3-21

3.6.5 Calculated Longitudinal Residual Voltage Protection ....................................................... 3-21

3.6.6 VT1 Circuit Failure Alarm and Blocking ............................................................................. 3-23

3.7 Phase-to-phase Backup Protection of Generator ...................................... 3-23

3.7.1 Voltage Controlled Overcurrent Protection ........................................................................ 3-23

3.7.2 Impedance Protection ........................................................................................................ 3-25

3.8 Stator Earth-fault Protection ........................................................................ 3-27

3.8.1 Fundamental Residual Overvoltage Protection ................................................................. 3-27

3.8.2 Third Harmonic Voltage Ratio Protection .......................................................................... 3-28

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3.8.3 Third Harmonic Voltage Differential Protection ................................................................. 3-29

3.8.4 VT Circuit Failure Blocking ................................................................................................ 3-29

3.8.5 Logic Scheme .................................................................................................................... 3-30

3.9 Stator Earth-fault Protection with Voltage Injection ................................... 3-32

3.9.1 Earthing Resistance Criterion ............................................................................................ 3-32

3.9.2 Earthing Current Criterion .................................................................................................. 3-33

3.9.3 External Voltage Circuit Monitoring ................................................................................... 3-33

3.9.4 Logic Scheme .................................................................................................................... 3-34

3.10 Rotor Earth-fault Protection with Ping-pang Type ................................... 3-34

3.10.1 One-point Earth-fault Protection ...................................................................................... 3-34

3.10.2 Two-points Earth fault Protection .................................................................................... 3-35

3.11 Rotor Earth-fault Protection with Voltage Injection .................................. 3-36

3.11.1 One-point Earth-fault Protection ...................................................................................... 3-36

3.11.2 Two-point Earth-fault Protection ...................................................................................... 3-37

3.12 Stator Overload Protection ......................................................................... 3-38

3.12.1 Definite-time Stator Overload Protection ......................................................................... 3-38

3.12.2 Inverse-time Stator Overload Protection ......................................................................... 3-39

3.13 Negative-sequence Overload Protection .................................................. 3-40

3.13.1 Definite-time Negative-sequence Overload Protection ................................................... 3-40

3.13.2 Inverse-time Negative-sequence Overload Protection ................................................... 3-41

3.14 Loss-of-excitation Protection ..................................................................... 3-42

3.14.1 Undervoltage Criterion ..................................................................................................... 3-42

3.14.2 Stator-side Impedance Criterion ...................................................................................... 3-43

3.14.3 Rotor-side Criterion ......................................................................................................... 3-44

3.14.4 Logic Scheme .................................................................................................................. 3-45

3.15 Out-of-step Protection ................................................................................ 3-46

3.16 Generator Voltage Protection ..................................................................... 3-48

3.16.1 Overvoltage Protection .................................................................................................... 3-48

3.16.2 Undervoltage Protection .................................................................................................. 3-49

3.17 Over-excitation Protection ......................................................................... 3-50

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3.17.1 Definite-time Over-excitation Protection .......................................................................... 3-50

3.17.2 Inverse-time Over-excitation Protection .......................................................................... 3-50

3.18 Power Protection......................................................................................... 3-51

3.18.1 Reverse Power Protection ............................................................................................... 3-51

3.18.2 Sequence Tripping Reverse Power Protection ............................................................... 3-52

3.18.3 Low Power Protection ...................................................................................................... 3-53

3.19 Frequency Protection ................................................................................. 3-53

3.19.1 Underfrequency Protection .............................................................................................. 3-53

3.19.2 Overfrequency Protection ................................................................................................ 3-53

3.19.3 Logic Scheme .................................................................................................................. 3-54

3.20 Inadvertent Energization Protection .......................................................... 3-54

3.21 Startup and Shutdown Protection ............................................................. 3-56

3.22 Overload Protection of Excitation Windings ............................................ 3-57

3.22.1 Definite-time Excitation Winding Overload Protection .................................................... 3-57

3.22.2 Inverse-time Excitation Winding Overload Protection ..................................................... 3-58

3.23 Excitation Transformer /Exciter Overcurrent Protection ......................... 3-59

3.24 Breaker Failure Protection at Generator Terminal ................................... 3-59

3.25 CT Circuit Supervision ............................................................................... 3-60

3.25.1 Three-phase Current Circuit Failure Alarm ..................................................................... 3-60

3.25.2 Differential Current Alarm in Differential Protection Circuit ............................................. 3-60

3.25.3 Alarm or Blocking to Differential Protection by CT Circuit Failure ................................... 3-61

3.26 VT Circuit Supervision ................................................................................ 3-61

3.26.1 VT Circuit of Any Side Failure Alarm ............................................................................... 3-61

3.26.2 Voltage Valance on Generator Terminals ........................................................................ 3-62

3.26.3 Three-phase Voltage Circuit Failure Supervision ............................................................ 3-62

3.27 Mechanical protection ................................................................................ 3-62

List of Figures

Figure 3.1-1 Hardware structure ................................................................................................ 3-1

Figure 3.3-1 Operation characteristic of differential protection............................................. 3-6

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Figure 3.3-2 Operation characteristic of HSDP ........................................................................ 3-9

Figure 3.3-3 Logic diagram of differential protection ............................................................ 3-11

Figure 3.4-1 Operation characteristic of percentage differential protection ...................... 3-12

Figure 3.4-2 Logic diagram of differential protection ............................................................ 3-15

Figure 3.5-1 Operating characteristic of DPFC percentage differential protection ........... 3-17

Figure 3.5-2 Logic diagram of DPFC percentage differential protection ............................ 3-17

Figure 3.6-1 Logic diagram of high-setting stage transverse differential protection ........ 3-19

Figure 3.6-2 Logic diagram of sensitive stage transverse differential protection ............. 3-19

Figure 3.6-3 Logic diagram of longitudinal residual voltage protection ............................. 3-20

Figure 3.6-4 Logic diagram of calculated longitudinal residual voltage protection .......... 3-22

Figure 3.7-1 Logic diagram of overcurrent protection .......................................................... 3-25

Figure 3.7-2 Operation characteristic of impedance protection .......................................... 3-26

Figure 3.7-3 Logic diagram of impedance protection ........................................................... 3-27

Figure 3.8-1 Logic diagram of stator earth-fault protection ................................................. 3-31

Figure 3.9-1 Circuit design of stator earth-fault protection with voltage injection ............ 3-32

Figure 3.9-2 Logic diagram of stator earth-fault protection with voltage injection ........... 3-34

Figure 3.10-1 Schematic diagram of measurement principle ............................................... 3-35

Figure 3.10-2 Logic diagram of one-point earth fault protection ......................................... 3-35

Figure 3.10-3 Logic diagram of two-points earth fault protection ....................................... 3-36

Figure 3.11-1 Measuring scheme of voltage injection into the rotor winding at single-end

.............................................................................................................................................. 3-36

Figure 3.11-2 Measuring scheme of voltage injection into the rotor winding at double-ends

.............................................................................................................................................. 3-37

Figure 3.11-3 Logic diagram of one-point earth-fault protection ......................................... 3-37

Figure 3.11-4 Logic diagram of two-points earth-fault protection ....................................... 3-38

Figure 3.12-1 Logic diagram of definite-time stator overload protection ........................... 3-39

Figure 3.12-2 Operation curve of inverse-time stator overload protection ........................ 3-39

Figure 3.12-3 Logic diagram of inverse-time stator overload protection ........................... 3-40

Figure 3.13-1 Logic diagram of definite-time negative-sequence overload protection .... 3-41

Figure 3.13-2 Operation curve of inverse-time negative-sequence overload protection .. 3-41

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Figure 3.13-3 Logic diagram of inverse-time negative-sequence overload protection ..... 3-42

Figure 3.14-1 Operation characteristic of steady-state stabilization impedance circle .... 3-43

Figure 3.14-2 Operation characteristic of asynchronous impedance circle ...................... 3-44

Figure 3.14-3 Logic diagram of loss-of-excitation protection (stage 1) .............................. 3-45



Figure 3.15-1 Operation characteristic of out-of-step protection ........................................ 3-47

Figure 3.15-2 Logic diagram of out-of-step protection ......................................................... 3-48

Figure 3.16-1 Logic diagram of overvoltage protection ........................................................ 3-49

Figure 3.16-2 Logic diagram of undervoltage protection ..................................................... 3-49

Figure 3.17-1 Logic diagram of definite-time over-excitation protection ............................ 3-50

Figure 3.17-2 Inverse-time characteristics ............................................................................. 3-51

Figure 3.17-3 Logic diagram of inverse-time over-excitation protection ............................ 3-51

Figure 3.18-1 Logic diagram of reverse power protection ................................................... 3-52

Figure 3.18-2 Logic diagram of sequence tripping reverse power protection ................... 3-52

Figure 3.18-3 Logic diagram of low power protection .......................................................... 3-53

Figure 3.19-1 Logic diagram of underfrequency protection ................................................. 3-54

Figure 3.19-2 Logic diagram of overfrequency protection ................................................... 3-54

Figure 3.20-1 Logic diagram of inadvertent energization protection (standard version) . 3-55

Figure 3.20-2 Logic diagram of inadvertent energization protection (special version) .... 3-56

Figure 3.21-1 Logic diagram of generator startup and shutdown protection .................... 3-57

Figure 3.22-1 Logic diagram of definite time excitation winding overload protection ...... 3-57

Figure 3.22-2 Operation characteristic of inverse-time excitation winding overload

protection ............................................................................................................................ 3-58

Figure 3.22-3 Logic diagram of inverse-time excitation winding overload protection ...... 3-59

Figure 3.23-1 Logic diagram of excitation transformer or exciter overcurrent protection 3-59

Figure 3.24-1 Logic diagram of breaker failure protection ................................................... 3-60

3 Operation Theory


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3.1 Overview

The device has 2 plug-in modules (i.e. protection DSP module and fault detector DSP module),

and the logic relation between them is AND. They have independent sample circuit and output

circuit. AC current and voltage is converted into small voltage signal and sent to protection

calculation module (also called DSP module 1) and fault detector calculation module (also called

DSP module 2) respectively. Protection DSP module is responsible for protection calculation and

fault detector DSP module is responsible for fault detector. Fault detectors on fault detector DSP

module picks up to connect positive pole of power supply of output relays. Real-time data

exchange between protection DSP module and fault detector DSP module is performed. Based on

strict mutual check and self-check, any of them fails will lead to block the device and issue alarm

signal. The device will not mal-operate due to hardware error.

AC

Signal LPF A/D DSP

CPU

External BI

Output

RelayProtection DSP module

LPF A/D DSP

Fault detector DSP module

+E

Opto-

coupler

QDJ

Ethernet

Clock Synchronization

Serial port

Print

Figure 3.1-1 Hardware structure

3.2 Fault Detector (FD)

Each fault detector element will be enabled when the corresponding protection element is enabled.

After the fault detector element operates, the positive power supply will be provided to output relay

and pickup signal will keep 500ms even the fault detector element drops off. Tripping output is only

enabled if both corresponding fault detector element on fault detector DSP module and

corresponding protection element on protection DSP module operate, otherwise the device will

issue alarm signal. The fault detector element with the prefix of FD_ will delay drop-off with a

time delay of 500ms, and the fault detector element with the prefix of St_ will dropoff with no

time delay. The principle of each fault detector element is given below:

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3.2.1 Differential Protection of Generator

When the differential current of generator is greater than the setting [I_Pkp_PcntDiff_Gen], the

fault detector element of generator differential protection [FD_Diff_Gen] and [St1_DiffProt_Gen]

will operate.

When the fundamental variation of differential current is greater than the threshold value, the fault

detector element of generator differential protection [FD_Diff_Gen] and [St2_DiffProt_Gen] will

operate.

3.2.2 Inter-turn Protection of Generator

When the transverse differential current of generator is greater than the setting

[I_SensTrvDiff_Gen], the fault detector element of generator transverse differential protection

[FD_IntTurn_Gen] and [St_TrvDiffProt_Gen] will operate.

When the longitudinal residual voltage is greater than the setting [V_SensROV_Longl_Gen], the

fault detector element of longitudinal residual voltage protection [FD_IntTurn_Gen] and

[St_ROV_Longl_Gen] will operate.

When the fundamental variation of negative-sequence voltage, current and power are greater than

their threshold values, the fault detector element of DPFC inter-turn protection [FD_IntTurn_Gen]

and [St_DPFC_IntTurn_Gen] will operate.

When the calculated longitudinal residual voltage is greater than the setting

[V_SensROV_Longl_Gen], the fault detector element of longitudinal residual voltage protection

[FD_IntTurn_Gen] and [St_ROV_Longl2_Gen] will operate.

3.2.3 Stator Earth-fault Protection of Generator

When residual voltage of generator terminal and neutral point are greater than the setting

[V_SensROV_Sta], the fault detector element of residual voltage protection [FD_StaEF_Gen] and

[St_ROVProt_Sta] will operate.

When third harmonic voltage ratio is greater than the setting [k_V3rdHRatio_PreSync_Sta] or

[k_V3rdHRatio_PostSync_Sta], the fault detector element of third harmonic voltage ratio

protection [FD_StaEF_Gen] and [St_V3rdHRatio_Sta] will operate.

3.2.4 Stator Earth-fault Protection with Voltage Injection of Generator

When the calculated earth resistance is lower than the resistance setting [R_Trp_Inj_EF_Sta], the

fault detector element [FD_InjStaEF_Gen] and [St_InjR_Sta] will operate.

When earthing current of stator without being subjected to digital filter is greater than the current

setting [I_ROC_Inj_EF_Sta], the fault detector element [FD_InjStaEF_Gen] and [St_InjI0_Sta] will

operate.

3.2.5 Rotor Earth-fault Protection of Generator

When grounded resistance of rotor windings is smaller than its setting [R_1PEF_RotWdg], the

fault detector element of rotor one-point earth-fault protection [FD_EF_RotWdg] and

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[St_1PEF_RotWdg] will operate.

When the change of rotor grounding location is greater than its internally fixed setting, the fault

detector element of rotor two-points earth-fault protection will [FD_EF_RotWdg] and

[St_2PEF_RotWdg] operate.

3.2.6 Stator Overload Protection of Generator

When maximum value of three phase currents is greater than the setting [I_OvLd_Sta], the fault

detector element of definite-time overload protection [FD_StaOvLd_Gen] and [St_OvLd_Sta] will

operate.

When the inverse time accumulated value is greater than the setting [I_InvOvLd_Sta], the fault

detector element of inverse-time overload protection [FD_StaOvLd_Gen] and [St_InvOvLd_Sta]

will operate.

3.2.7 Negative-sequence Overload Protection of Generator

When maximum value of negative sequence current is greater than the setting [I_NegOC_Gen],

the fault detector element of definite-time negative-sequence overload protection

[FD_NegOC_Gen] and [St_NegOC_Sta] will operate.

When the inverse time accumulated value is greater than the setting [I_InvNegOC_Gen], the fault

detector element of inverse-time negative-sequence overload protection [FD_NegOC_Gen] and

[St_InvNegOC_Sta] will operate.

3.2.8 Loss-of-excitation Protection of Generator

When the locus of calculated impedance enters into impedance circle, the fault detector of

loss-of-excitation protection [FD_LossExc_Gen] and [St_LossExcn_Gen] (n can be 1, 2 or 3) will

operate.

3.2.9 Out-of-step Protection of Generator

When the locus of calculated impedance leaves boundary of impedance operation zone, the fault

detector of out-of-step protection [FD_OOS_Gen] and [St_x_OOS_Gen] (x can be Ext or Int) will

operate.

3.2.10 Voltage Protection of Generator

When maximum value of three phase-to-phase voltage is greater than the setting [V_OVn_Gen],

the fault detector element of overvoltage protection [FD_VoltProt_Gen] and [St_OVn_Gen] will

operate (n can be 1 or 2).

When maximum value of three phase-to-phase voltage is greater than the setting [V_UV_Gen],

the fault detector element of overvoltage protection [FD_VoltProt_Gen] and [St_UV_Gen] will

operate.

3.2.11 Over-excitation Protection of Generator

When the measured U/F is greater than the setting [k_OvExc1_Gen], the fault detector element of

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Date: 2013-06-28

definite-time over-excitation protection [FD_OvExc_Gen] and [St_OvExc1_Gen] will operate.

When the accumulated value is greater than the setting [k0_InvOvExc_Gen], the fault detector

element of inverse-time over-excitation protection [FD_OvExc_Gen] and [St_OvExc2_Gen] will

operate.

3.2.12 Power Protection of Generator

When reverse power is greater than setting [P_RevP_Gen], the fault detector of reverse power

protection [FD_PwrProt_Gen] and [St_RevP_Gen] will operate.

When reverse power is greater than setting [P_SeqTrpRevP_Gen], the fault detector of reverse

power protection [FD_PwrProt_Gen] and [St_SeqTrpRevP_Gen] will operate.

When power is lower than setting [P_UP_Gen] and the binary input [BI_NotUrgBrake] is energized,

the fault detector of low power protection [FD_PwrProt_Gen] and [St_UP_Gen] will operate.

3.2.13 Frequency Protection of Generator

When the frequency is smaller than the setting value for a specified time interval, the fault detector

element of low-frequency protection [FD_Freq_Gen] and [St_UFn_Gen] (n can be 1, 2 or 3) will

operate.

When the frequency is greater than the setting value for a specified time interval, the fault detector

element of over-frequency protection [FD_Freq_Gen] and [St_OFx_Gen] (x can be 1 or 2) will

operate.

3.2.14 Inadvertent Energization Protection of Generator

When the maximum value of three phase currents of generator is greater than the setting

[I_OC_AccEnerg_Gen], the fault detector element of generator inadvertent energization protection

[FD_AccEnerg_Gen] and [St_AccEnerg_Gen] will operate.

3.2.15 Startup/shutdown Protection of Generator

When the differential current of generator is greater than the setting [I_GenDiff_StShut_Gen], the

fault detector element of generator startup/shutdown protection [FD_StShut_Gen] and

[St_GenDiff_StShut_Gen] will operate.

When the residual voltage of generator is greater than the setting [V_StaROV_StShut_Gen], the

fault detector element of generator startup/shutdown protection [FD_StShut_Gen] and

[St_StaROV_StShut_Gen] will operate.

When the low-frequency current of generator neutral point is greater than the setting

[I_OC_StShut_Gen], the fault detector element of generator startup/shutdown protection

[FD_StShut_Gen] and [St_OC_StShut_Gen] will operate.

3.2.16 Differential Protection of Excitation Transformer/Exciter

When the maximum value of three phase differential currents is greater than the setting

[I_Pkp_PcntDiff_Exc], the fault detector element of differential protection [FD_Diff_Exc] and

[St_DiffProt_Exc] will operate.

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3.2.17 Overcurrent Protection/Overload Protection of Excitation

Transformer/Exciter

When the maximum value of three phase currents is greater than the setting [I_OCn_Exc] (n can

be 1 or 2), the fault detector element of overcurrent protection [FD_Bak_Exc] and [St_OCn_Exc]

will operate.

3.2.18 Breaker Failure Protection at Generator Terminal

When the binary input [BI_ExtTrpCtrl] is energized, and phase current or negative-sequence

current is greater than the setting value, the fault detector element of breaker failure protection

[FD_BFPGCBProt] and [St_BFPGCBProt] will operate.

3.2.19 Mechanical Protection

When the operation duration of mechanical protection is greater than its time delay, the fault

detector element of mechanical protection [FD_MechRly] and [St_MechRlyn] (n can be 1, 2, 3, 4,

5, 6, 7 or 8) will operate.

Note!

These setting values of above fault detector elements are formed automatically by the

device, it needs not to set manually.

3.3 Differential Protection of Excitation Transformer/Exciter

3.3.1 Operation Characteristic

Operation cr

nari pcs-985g generator relay

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