pcs-931 my instruction manual en general x r1.00 (en xlbh5104.0060.1101)

8/19/2019 PCS-931 MY Instruction Manual en General X R1.00 (en XLBH5104.0060.1101)

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PCS-931_MY

Line Differential Relay

Instruction Manual

Nanjing Nari-Relays Electric Co., Ltd.


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PCS-931 Line Differential Relay

NANJING NARI-RELAYS ELECTRIC CO., LTD i

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 NARI-RELAYS 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 ofthis 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).


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NANJING NARI-RELAYS ELECTRIC CO., LTDii

Instructions and Warnings

The following indicators and standard definitions are used:

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!


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NANJING NARI-RELAYS ELECTRIC CO., LTD iii

Exposed terminals

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

generated is dangerous

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

Manual: V1.00

P/N: EN_XLBH5104.0060.1101

Copyright © NR 2009. All rights reserved

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.

NANJING NARI-RELAYS ELECTRIC CO., LTD.

69 SuYuan. Avenue, Nanjing 211102，China

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

Website: www.nari-relays.com

Email: [email protected]


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NANJING NARI-RELAYS ELECTRIC CO., LTDiv

Table of Contents

Preface ....................................................................................................................................... i

Introduction ........................................................................................................................ i

Health and Safety .............................................................................................................. i

Instructions and Warnings ...............................................................................................ii

Table of Contents .....................................................................................................................iv

Chapter 1 Introduction .............................................................................................................1

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

1.2 Function .......................................................................................................................2

1.3 Features ........................................................................................................................3

Chapter 2 Technical Data .........................................................................................................5

2.1 Electrical Specifications .............................................................................................5

2.1.1 Analog Input Ratings .........................................................................................5

2.1.2 Power Supply .....................................................................................................5

2.1.3 Binary Input .......................................................................................................6

2.1.4 Binary Output.....................................................................................................6

2.1.5 Power Supply Output for Opto-coupler ...........................................................6

2.2 Mechanical Specifications ..........................................................................................6

2.3 Ambient Temperature and Humidity Range ..............................................................7

2.4 Communication Port ...................................................................................................7

2.4.1 Communication Port for RTU/SCADA .............................................................7

2.4.2 Communication Port for Print ..........................................................................8

2.4.3 RS-485 for Clock Synchronization ...................................................................8

2.5 Type Tests ....................................................................................................................8

2.5.1 Environmental Tests ..........................................................................................8

2.5.2 Mechanical Tests ...............................................................................................8

2.5.3 Electrical Tests ..................................................................................................8

2.5.4 Electromagnetic Compatibility .........................................................................9

2.6 Certifications ..............................................................................................................10


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2.7 Protective Functions .................................................................................................10

2.7.1 Optical Interface ..............................................................................................10

2.7.2 Fault Detector ..................................................................................................10

2.7.3 Current Differential Protection ....................................................................... 11

2.7.4 DPFC Distance Protection .............................................................................. 11

2.7.5 Distance Protection ......................................................................................... 11

2.7.6 Directional Zero-sequence Overcurrent Protection ..................................... 11

2.7.7 Directional Phase Overcurrent Protection .................................................... 11

2.7.8 Inverse-time Zero-sequence Overcurrent Protection ................................... 11

2.7.9 Breaker Failure Protection ..............................................................................12

2.7.10 Transient Overreach ......................................................................................12

2.7.11 Fault Locator ..................................................................................................12

2.7.12 Auto-Reclosing ..............................................................................................12

Chapter 3 Protection Description ..........................................................................................13

3.1 General Description ..................................................................................................13

3.2 General Fault Detector Element (GFD) ....................................................................13

3.2.1 DPFC Overcurrent Element ............................................................................13

3.2.2 Zero-sequence Overcurrent Element .............................................................14

3.2.3 Auxiliary Voltage Element ...............................................................................14

3.2.4 Transfer Trip Element ......................................................................................15

3.3 Protective Fault Detector Element (PFD) .................................................................15

3.4 DPFC Distance Protection ........................................................................................15

3.5 Current Differential Protection .................................................................................16

3.5.1 Application .......................................................................................................16

3.5.2 Function Description .......................................................................................17

3.5.3 Logic Scheme ..................................................................................................28

3.6 Overcurrent Protection .............................................................................................35

3.6.1 Application .......................................................................................................35

3.6.2 Directional Zero-sequence Overcurrent Protection .....................................35

3.6.3 Directional Phase Overcurrent Protection ....................................................37


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3.6.4 Inverse-time zero-sequence overcurrent protection ....................................38

3.6.5 Overcurrent Protection when VT Circuit Failure...........................................40

3.7 Distance Protection ...................................................................................................40

3.7.1 Distance Element with Memorized Polarization ............................................41

3.7.2 Phase-to-ground Distance Element ...............................................................43

3.7.3 Phase-to-phase distance element ..................................................................46

3.7.4 Reversal Distance Element .............................................................................46

3.7.5 Blinder Scheme ...............................................................................................47

3.7.6 Power Swing Blocking Releasing (PSBR) .....................................................47

3.7.7 Scheme Logic ..................................................................................................49

3.8 Breaker Failure Protection ........................................................................................51

3.8.1 Overview ..........................................................................................................51

3.8.2 Function Description .......................................................................................51

3.8.3 Logic Scheme ..................................................................................................51

3.9 Switch onto Fault Protection ....................................................................................52

3.9.1 Zero-sequence SOTF Protection ....................................................................53

3.9.2 Distance SOTF Protection ..............................................................................54

3.10 Fault Phase Selection (FPS) ...................................................................................54

3.10.1 FPS Based on Deviation of Operation Voltage ...........................................54

3.10.2 FPS Based on Differential Current ...............................................................55

3.10.3 FPS Based on Phase Difference between I0 and I2A ...................................55

3.11 Pole Disagreement ..................................................................................................56

3.11.1 PD State by Single-phase Trip ......................................................................56

3.11.2 PD State by Three-phase Trip .......................................................................57

3.12 Trip Scheme .............................................................................................................57

3.13 Synchronism Check ................................................................................................63

3.13.1 Overview ........................................................................................................63

3.13.2 Function Description .....................................................................................63

3.13.3 Logic Scheme ................................................................................................64

3.14 Automatic Reclosure ...............................................................................................65


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3.14.1 Overview ........................................................................................................65

3.14.2 Function Description .....................................................................................66

3.15 Transfer Trip And Transfer Signal ..........................................................................69

3.15.1 Transfer Trip ...................................................................................................70

3.15.2 Transfer signal ...............................................................................................70

Chapter 4 Automatic Supervision .........................................................................................71


4.2 Understand the Alarms ..............................................................................................71

4.3 Relay Self-supervision ..............................................................................................74

4.3.1 Fault Detection Check .....................................................................................74

4.3.2 Trip Output Circuit Check ...............................................................................74

4.3.3 Settings Check.................................................................................................74

4.4 AC Input Monitoring ..................................................................................................74

4.4.1 Voltage and Current Drift Auto Regulation ....................................................74

4.4.2 DSP Sampling Monitoring ...............................................................................75

4.5 Secondary Circuit Monitoring ..................................................................................75

4.5.1 Opto-coupler Power Supervision ...................................................................75

4.5.2 Circuit Breaker Supervision ...........................................................................75

4.5.3 Bus VT Circuit Supervision ............................................................................75

4.5.4 Line VT Circuit Supervision ............................................................................76

4.5.5 CT Circuit Supervision ....................................................................................76

4.5.6 Binary Input Supervision ................................................................................77

Chapter 5 Metering and Recording .......................................................................................79

5.1 Metering ......................................................................................................................79

5.2 Event & Fault Record ................................................................................................81

5.2.1 General Description ........................................................................................81

5.2.2 Event Recorder ................................................................................................81

5.2.3 Disturbance Recorder .....................................................................................82

5.2.4 Present Recording ...........................................................................................83

Chapter 6 Hardware Description ...........................................................................................85


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6.2 Typical Wiring ............................................................................................................86

6.3 Plug-in Modules .........................................................................................................89

6.3.1 MON Module ....................................................................................................89

6.3.2 DSP Module (Protection Function Calculation) ............................................91

6.3.3 DSP Module (Fault Detector Logic Calculation) ...........................................91

6.3.4 AI Module .........................................................................................................92

6.3.5 GOOSE Module ................................................................................................94

6.3.6 BI Module .........................................................................................................98

6.3.7 BO Module .....................................................................................................105

6.3.8 BO Module .....................................................................................................106

6.3.9 BO Module .....................................................................................................108

6.3.10 BO Module ................................................................................................... 110

6.3.11 BO Module .................................................................................................... 111

6.3.12 PWR Module................................................................................................. 112

6.4 Display Panel ........................................................................................................... 114

Chapter 7 Configurable Function ........................................................................................ 115

7.1 General Description ................................................................................................ 115

7.2 Introduction on PCS-PC software .......................................................................... 115

7.3 Protective Device Configuration ............................................................................ 115

7.3.1 Configuration of LED Indicators .................................................................. 115

7.3.2 Configuration of Binary Input ....................................................................... 116

7.3.3 Configuration of Binary Output .................................................................... 117

Chapter 8 Settings ................................................................................................................ 119

8.1 Equipment Parameters ............................................................................................ 119

8.2 System Parameters .................................................................................................121

8.3 Protection Settings ..................................................................................................122

8.4 Logic Settings ..........................................................................................................136

8.5 Equipment VEBI Settings ........................................................................................143

8.6 GOOSE VEBI Settings .............................................................................................143


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Chapter 9 Human Machine Interface ...................................................................................145

9.1 Overview ...................................................................................................................145

9.1.1 Keypad Operation ..........................................................................................146

9.1.2 LED Indications .............................................................................................146

9.1.3 Communication Port .....................................................................................148

9.1.4 Communication .............................................................................................148

9.2 Understand the HMI Menu Tree ..............................................................................149

9.2.1 Overview ........................................................................................................149

9.2.2 VALUES ..........................................................................................................152

9.2.3 REPORT .........................................................................................................152

9.2.4 PRINT ..............................................................................................................153

9.2.5 SETTINGS ......................................................................................................154

9.2.6 LOCAL CONTROL .........................................................................................154

9.2.7 CLOCK ............................................................................................................155

9.2.8 VERSION ........................................................................................................155

9.2.9 TEST_MODE ..................................................................................................155

9.2.10 INTERFACE ..................................................................................................156

9.3 Understand the LCD Display ..................................................................................156

9.3.1 Overview ........................................................................................................156

9.3.2 Normal Status Display ...................................................................................156

9.3.3 Display Fault Report ......................................................................................157

9.3.4 Display Self-supervision Report ..................................................................159

9.3.5 Display Binary Input Change Report ...........................................................160

9.3.6 Display Control Report .................................................................................164

9.4 Keypad Operation ....................................................................................................164

9.4.1 View Device Status ........................................................................................164

9.4.2 View Device Report .......................................................................................164

9.4.3 View Module Information ..............................................................................165

9.4.4 Print Device Report .......................................................................................165

9.4.5 View Device Setting .......................................................................................166


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9.4.6 Modify Device Setting ...................................................................................167

9.4.7 Copy Device Setting ......................................................................................169

9.4.8 Switch Setting Group ....................................................................................169

9.4.9 Delete Device Message .................................................................................170

9.4.10 Modify Device Clock ....................................................................................170

9.4.11 Check Software Version ..............................................................................170

9.4.12 Communication Test ...................................................................................171

Chapter 10 Communications ...............................................................................................173

10.1 General Description...............................................................................................173

10.2 Rear Communication Port Information ................................................................173

10.2.1 RS-485 Interface ..........................................................................................173

10.2.2 Ethernet Interface ........................................................................................175

10.2.3 IEC60870-5-103 Communication ................................................................176

10.3 IEC60870-5-103 Interface over Serial Port ...........................................................176

10.3.1 Physical Connection and Link Layer .........................................................176

10.3.2 Initialization ..................................................................................................176

10.3.3 Time Synchronization .................................................................................177

10.3.4 Spontaneous Events ...................................................................................177

10.3.5 General Interrogation ..................................................................................177

10.3.6 General Service ...........................................................................................177

10.3.7 Disturbance Records ..................................................................................178

10.4 IEC60870-5-103 Interface over Ethernet ..............................................................178

10.5 Messages Description for IEC61850 Protocol .....................................................178

10.5.1 Overview ......................................................................................................178

10.5.2 Communication profiles .............................................................................179

10.5.3 Server data organization .............................................................................180

10.5.4 Server features and configuration .............................................................182

10.5.5 ACSI Conformance ......................................................................................184

10.5.6 Logical Nodes ..............................................................................................188

10.6 GOOSE Service ......................................................................................................191


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10.6.1 GOOSE Introduction ...................................................................................191

10.6.2 GOOSE Function .........................................................................................191

Chapter 11 Installation and Commissioning ......................................................................193

11.1 Introduction ............................................................................................................193

11.2 Safety Information .................................................................................................193

11.3 Overview ................................................................................................................. 195

11.4 Unpacking And Checking The Protection Equipment ........................................195

11.5 Installing The Protective Device ...........................................................................196

11.5.1 Overview .......................................................................................................196

11.5.2 Dimensions ..................................................................................................197

11.5.3 Grounding Guidelines .................................................................................197

11.5.4 Cubicle Grounding ......................................................................................198

11.5.5 Ground Connection on the Device .............................................................199

11.5.6 Grounding Strips and their Installation......................................................199

11.5.7 Making the electrical connections .............................................................200

11.6 Check the External Circuit ....................................................................................201

11.7 Energizing The Protective Device ........................................................................202

11.8 Setting The Protective Device ..............................................................................203

11.9 Establishing Connection And Verifying Communication ...................................204

11.10 Verifying Settings by Secondary Injection ........................................................204

11.10.1 Insulation Test (if required) .......................................................................205

11.10.2 AC Measurement Check ............................................................................205

11.10.3 Print Fault Report ......................................................................................206

11.10.4 On-load Checks .........................................................................................206

11.11 Final Check ...........................................................................................................207

Chapter 12 Maintenance ......................................................................................................209

12.1 Appearance Check ................................................................................................209

12.2 Failure Tracing And Repair ...................................................................................209

12.3 Replace Failed Modules ........................................................................................210

12.4 Replace Button Battery ......................................................................................... 211


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12.5 Cleaning ................................................................................................................. 211

12.6 Storage ................................................................................................................... 211

Chapter 13 Decommissioning and Disposal ......................................................................213

13.1 Decommissioning ..................................................................................................213

13.2 Disposal ..................................................................................................................213

Chapter 14 Manual Version History .....................................................................................215


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Chapter 1 Introduction

NANJING NARI-RELAYS ELECTRIC CO., LTD 1


1.1 Application

The PCS-931 is a digital EHV line differential relay with the main and back-up protection functions,

which mainly is designed for transmission line of 220KV and above.

PCS-931 Optical fibre channel PCS-931

Figure 1.1-1 Typical application of PCS-931

The main protection of PCS-931 comprises of current differential protection, which can clear the

fault immediately for the whole line. DPFC distance protection can reach to extremely fast speed

for the fault near the busbar.

The back-up protection of PCS-931 comprises of distance protection, directional zero-sequence

overcurrent protection, inverse-time zero-sequence overcurrent protection, directional phase

overcurrent protection and breaker failure protection. Specially, one zone reversal distance

protection is also available in PCS-931. In addition, as a substitution, phase/zero-sequence

overcurrent protections are put into service automatically when VT circuit is failure.

Figure 1.1-2 Functional diagram of PCS-931


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PCS-931 can implement single-phase or three-phase trip and configurable auto-reclosing that can

implement 1-pole AR, 3-poles AR and 1/3-pole AR.

1.2 Function

1. Main protection

Current differential protection (87)

DPFC current differential element

Steady-state current differential element

Zero-sequence current differential element

DPFC distance protection (21D)

2. Backup protection

Phase-to-phase distance protection (21P)

Phase-to-ground distance protection (21G)

Reversal distance protection (21R)

Directional zero-sequence overcurrent protection (67G)

Instantaneous zero-sequence overcurrent protection (50G)

Definite-time zero-sequence overcurrent protection (51G)

Directional phase overcurrent protection (67P)

Definite-time phase overcurrent protection (51P)

Inverse-time phase overcurrent protection (IDMT)

Inverse-time zero-sequence overcurrent protection (IDMT)

Breaker failure protection (50BF)

Phase overcurrent protection when VT circuit failure (51PVT)

Zero-sequence overcurrent protection when VT circuit failure (51GVT)

Switch onto fault (SOTF)

Distance protection for SOTF

Directional zero-sequence overcurrent protection for SOTF

3. Additional function

Power swing blocking releasing (PSBR)

Auto-reclosing (79)


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Synchronism check (25)

VT circuit supervision (VTS)

CT circuit supervision (CTS)

Line VT circuit supervision (LVTS)

Self diagnostic test

Voltage and current drift auto regulation

Fault location (FL)

Fault phase selection (FPS)

Note!

DPFC is the abbreviation of “Deviation of Power Frequency Component”. In case of a fault

in the power system, the fault current consists of three parts: the power frequency

components before the fault, the power frequency variables during the fault and the

transient variables during the fault. DPFC is the power frequency variables during the fault.

1.3 Features

1. Protection and Control

It adopts the new UAPC hardware platform of NR, and its AC inputs can support the electric

instrument transformer and conventional instrument transformer.

It adopts the high performance MCU and DSP processors, high-speed inner bus and

intelligent I/O interfaces. The modularization design of the hardware and software makes this

device be configured to meet the demands of different practical application, and it is very

convenient for maintenance.

High precision 16 bits A/D converter is adopted in this protection device.

This protection device can communicate with SAS or RTU, optional communication protocol:

IEC60870-5-103 or IEC61850

Quickly clearing the internal fault for whole line, the time is less than 10 ms for fault where is

near the busbar, is less than 15ms for fault where is in the center of line and is less than 25ms

for fault where is in the remote end.

Plug connectors from the relay rear panel to the terminal blocks on the rack or cabinet, which

makes the on-site commissioning and replacement much easier than what you do the

commissioning using the traditional screw terminals on the rear panel.

Two independent data acquisition paths, one for fault detector element and another for

protections and logic functions, to prevent any undesired trip.


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The unique DPFC distance element is integrated in the protective device, which can clear the

internal fault quickly with high sensitivity and high speed and is not affected by power swing.

Self-adaptive floating threshold which only reflects deviation of power frequency component

can defend system imbalance and system disturbance. Hence, it is both rather reliable and

very fast, and it is very sensitive but does not pickup frequently.

Main protection adopts integral transform to ensure high-speed; Back-up protection adopts

Fourier transform, which has an excellent filtering result, to ensure accuracy.

24 samples per cycle, all task including data measurement, protection calculation, logic

discrimination, event recording and protection logic calculation could be done within one

sampling period.

GPS clock synchronization – PPS (pulse per second), PPM (pulse per minute) and IRIG-B

synchronization

High-speed 2048kbit/s multiplex channel or dedicated channel

2. Communication

2 RS-485 communication rear ports conform to IEC 60870-5-103 protocol

1 RS-485 communication rear ports for clock synchronization

2~4 optional Ethernet ports, IEC 61850, or IEC 60870-5-103 over TCP/IP

2 optional Ethernet port via optic fiber (ST interface or SC interface)

3. Monitoring and Metering

Event Recorder including 1024 tripping report, 1024 binary input change reports, 1024

self-supervision reports and 1024 control reports.

Disturbance recorder including 64 fault reports with waveforms (The file format of disturbance

recorder is compatible with international COMTRADE file.)

Self diagnostic test

4. User Interface

Friendly HMI interface with 320×240-dot LCD and 9-button keypad on the front panel.

1 RS-232 communication rear ports for printer

Multi-language - English, Chinese, Russian option

Auxiliary software - PCSPC


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Chapter 2 Technical Data



2.1 Electrical Specifications

2.1.1 Analog Input Ratings

1. Analog current

Standard IEC 60255-27:2005

Phase rotation ABC

Nominal frequency 50±5Hz, 60±5Hz

Rated Current 1A 5A

Linear to 0.05In~40In 0.05In~40In

Thermal withstand

-continuously

-for 10s

-for 1s

-for half a cycle

4In

30In

100In

250In

4In

30In

100In

250In

Burden < 0.2VA/phase @In < 0.25VA/phase @In

2. Analog voltage


Rated Voltage (Un) 100V, 110V 200V

Linear to 0.01Un~1.7Un 0.01Un~1.7Un

Thermal withstand

-continuously

-10s

-1s

2Un

2.6Un

3Un

1.1Un

1.9Un

2.1Un

Burden at rated < 0.25VA/phase @Un

2.1.2 Power Supply

Standard IEC 60255-11:2008 Rated Voltage 110V/125V, 220V/250V

Variation 80%Un~120%Un

Permissible AC ripple

voltage ≤15% of the nominal auxiliary voltage

Voltage short

interruptions 100ms for interruption without de-energizing

Voltage dips Up to 10s for dips 40%Un without reset

Burden

Quiescent condition

Operating condition


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2.1.3 Binary Input

Rated Voltage (Un) 24V, 48V, 110V, 125V, 220V, 250V

Maximal pickup

voltage 70%Un

Minimum dropout

voltage 55%Un

Maximum permissible

voltage 120%Un

Withstand 2000VAC, 3000VDC

Resolving time for

logic input


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Display language English

Housing material Aluminum

Location of terminal Rear panel of the device

Protection class

Standard IEC 60225-1:2007Front side IP40, up to IP51 (Flush mounted)

Other sides IP30

Rear side, connection

terminalsIP20

2.3 Ambient Temperature and Humidity Range


Operatingtemperature

-25°C to +55°C

Transport and storage

temperature range-40°C to +70°C

Permissible humidity 5%-95%, condensation not permissible

2.4 Communication Port

2.4.1 Communication Port for RTU/SCADA

RS-485

(EIA)

Electrical

Port number 2

Baud rate 4800,9600,19200,38400,57600,115200

Transmission distance


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Transmission standard 100Base-TX

Transmission distance


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


Impulse voltage tests Test voltage 5kV

Insulation resistance

measurements

Isolation resistance >100M@500VDC

2.5.4 Electromagnetic Compatibility

1MHz burst

disturbance test

Per IEC 60255-22-1:2007

Common mode: class III 2.5KV

Differential mode: class III 1.0KV

Electrostatic

discharge test

Per IEC60255-22-2:2008 class IV

For contact discharge: 8kV

For air discharge: 15kV

Radio frequency

interference tests

Per 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

Per 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 Per IEC 60255-22-5:2008

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

Common mode: 2kV

Differential mode: 1kV

Conducted RF

Electromagnetic

Disturbance

Per IEC 60255-22-6:2001

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

kHz~80MHz

Power FrequencyMagnetic Field

Immunity

Per IEC 61000-4-8:2001

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

Pulse Magnetic Field

Immunity

Per IEC 61000-4-9:2001

class V, 6.4/16μs, 1000A/m for 3s

Damped oscillatory

magnetic field

immunity

IEC 61000-4-10:2001

class V, 100kHz & 1MHz–100A/m


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2.6 Certifications

ISO9001: 2000

ISO14001:2004

OHSAS18001: 1999

ISO10012:2003

CMMI L3

EMC: 89/336/EEC, EN50263:2000

Products safety(PS): 73/23/EEC, EN61010-1: 2001, EN60950: 2002

2.7 Protective Functions

2.7.1 Optical Interface

Using multiplex channel or dedicated channel and transmission distance is smaller than 40kM,

PCS-931 is equipped with 1310nm laser emitter.

FO type: Single mode, CCITT Rec.G652, 1310nm

Send power: -14.0±2.0 dBm

Receive sensitivity: -35 dBm

Maximum transmission distance: -8 dBm

Using dedicated channel and transmission distance is greater than 40kM, PCS-931 is equipped

with 1550nm laser emitter.

FO type: Single mode, CCITT Rec.G652, 1550nm

Send power: -14.0±2.0 dBm

Receive sensitivity: -35 dBm

Maximum transmission distance: -8 dBm

2.7.2 Fault Detector

2.7.2.1 DPFC Overcurrent Element

Setting range: 0.1In~0.5In

Accuracy: ≤2.5% or 0.02In whichever is greater


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2.7.2.2 Zero-sequence Overcurrent Element

Setting range: 0.1In~0.5In

Accuracy: ≤2.5% or 0.02In whichever is greater

2.7.3 Current Differential Protection

Current setting accuracy: ≤5% or 0.04In whichever is greater

Time delay accuracy:


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Accuracy: ≤ 5% of reference (calculated) value +2%current tolerance, respectively 40ms

2.7.9 Breaker Failure Protection

Time delay: 0.01s~10s

Accuracy: ≤1%Setting+40ms

2.7.10 Transient Overreach

Tolerance for all high-speed protection: ≤2%

2.7.11 Fault Locator

Accuracy for multi-phase faults with one end source: < ±2.5%

Tolerance will be higher in case of single-phase fault with high ground resistance.

2.7.12 Auto-Reclosing

Item Range Accuracy

Frequency difference 0.01~1.00 Hz ±0.01 Hz

Phase difference 0~89 deg ±2.0 deg

Voltage difference 0.02~0.8Un ±1.0% Un

Item Range Accuracy

Reclosing time 0.01~50

±0.5%±10ms

Reclosing pulse length 0.01~50Time of circuit breaker in closed state before AR ready 0.01~250

Maximal waiting time of the synchronism check 0.01~250

Check time of AR unsuccessful 0.01~250

Reset time 0.01~250


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Chapter 3 Protection Description



3.1 General Description

Designing hardware platform of PCS-931 based on the dual processor (DSP and CPU), two

independent fault detector elements are provided for each protection logic, i.e. GFD (general fault

detector element) and PFD (protective fault detector element).

GFD is used to control the output circuit of the protective device. PFD is used to trigger the

calculation of protective elements. Under the normal condition, the positive pole of DC power

supplied to tripping outputs is continually supervised by GFD, and the output circuit will be

switched on for tripping or reclosing only when GFD operates. It means that the relay will have the

capability to output a final tripping or reclosing signal while both GFD and PFD operate.

3.2 General Fault Detector Element (GFD)

Main part of GFD is DPFC overcurrent fault detector element that reflects the deviation of

phase-to-phase power frequency current, and zero-sequence overcurrent fault detector element

that reflects total current is taken as supplementary.

The GFD comprise of the following elements:

DPFC overcurrent element

Zero-sequence overcurrent element

Auxiliary voltage element

Transfer trip element

If any of the above fault detector elements operates, the GFD will operate to provide DC power

supply to the output relays to enable the output circuit.

3.2.1 DPFC Overcurrent Element

This element adopts adaptive floating threshold which consists of unbalanced output of deviation.

The adaptive floating threshold is kept higher than the unbalanced output all along, which makes it

not pick up frequently and have an extremely high sensitivity and reliability. By using adaptive

floating threshold, the unbalanced output value is small under normal condition, so this element

has extremely high sensitivity. When power swing occurs, the adaptive floating threshold

increases while the sensitivity decreases automatically, so it is not influenced by power swing

condition and need not be controlled by power swing blocking element.

Its criterion:

ΔIΦΦMAX>1.25ΔITh+ΔISet (Equation 3.2-1)


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Where:

ΔIΦΦMAX: The maximum half-wave integration value of phase-to-phase current

ΔISet: The fixed threshold value (i.e. the setting [I_DPFC_OC_FD])

ΔITh: The floating threshold value

If operating condition is met, DPFC overcurrent element will operate to provide DC power supply

for output relay, and pickup signal will be kept 7 seconds after DPFC overcurrent element drops

out.

3.2.2 Zero-sequence Overcurrent Element

This element will operate when both 3I0 and 3I0Cal are greater than the setting [I_ROC_FD].

Where:

3I0: zero-sequence current derived at the neutral current circuit from three-phase currents

3I0Cal: zero-sequence current calculated depending on the summation of I A, IB and IC (i.e.

3I0Cal=I A+IB+IC)

If operating condition is met, zero-sequence overcurrent element will operate to provide DC power

supply for output relay, and pickup signal will be kept 7 seconds after zero-sequence overcurrent

element drops out.

When CT circuit failure is detected, this element will be disabled and an alarm [Alm_CTS] will be

issued.

Note!

The zero-sequence current should be connected to the protective device; otherwise all

protection elements corresponding with zero-sequence current will be blocked.

3.2.3 Auxiliary Voltage Element

Because DPFC overcurrent element and zero-sequence overcurrent element might not operate in

some special cases, in order to ensure protection device pick up in following three conditions,

PCS-931 provides auxiliary voltage element.

1. Internal fault associated with high fault resistance

2. In the case of weak infeed, internal unearthing fault

3. In the case of VT circuit failure or no VT connection, internal unearthing fault

The auxiliary voltage element will operate to provide DC power supply for output relay and pickup

signal will be kept 7 seconds after auxiliary voltage element drops out.

Note!

Here UN is the rated secondary phase voltage of VT. UNN is the rated secondary


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phase-to-phase voltage of VT. (UN means phase voltage; UNN means phase-to-phase

voltage)

3.2.4 Transfer Trip Element

If the logic setting [En_FD_Ctrl_TT] is set as “0” and the transfer trip signal received from opposite

end of line, the transfer trip element will operate to provide DC power supply for output relay and

pickup signal will be kept 500ms after transfer trip element drops out.

3.3 Protective Fault Detector Element (PFD)

The protective fault detection element is the same as the general fault detection element.

3.4 DPFC Distance Protection

The power system is normally treated as a balanced symmetrical three-phase network. When a

fault occurs in the power system, by applying the principle of superposition, the load currents and

voltage can be calculated in the system prior to the fault and the pure fault component can be

calculated by whole fault current or voltage subtracted by load current or voltage. DPFC distance

protection reflects deviation of power frequency, therefore, only pure fault current and voltage is

useful to DPFC distance protection which is not influenced by load current and voltage.

For forward direction fault

ZZDZK

ZS+ZK

-ZS

R

jX

Figure 3.4-1 Operation characteristic for forward fault

ZZD: The setting of distance protection

ZS: Total impedance between local system and protective device location

ZK: Measurement impedance

Figure 3.4-1 shows the operation characteristic of the DPFC distance element on R-X plane when


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a fault occurs in forward direction, which is the circle with the –Zs as the center and the│Zs+Zzd│

as the radius. When measured impedance Zk is in the circle, the DPFC distance element will

operate. The DPFC distance element has a large capability of enduring fault resistance. When

there is infeed current from power source at the other end in the fault resistance, the phase of ΔINis the same as

ΔI and the phase of voltage of fault resistance is same as

ΔI, so the fault resistance

appears resistive and is in parallel with R axes. The overreaching problem that results from infeed

current can be prevented.

For reverse direction fault

Figure 3.4-2 Operation characteristic for reverse fault

Z'S：Total impedance between remote system and protective device location

Figure 3.4-2 shows the operation characteristic of the DPFC distance element on R-X plane when

a fault occurs in reverse direction, which is the circle with the Z's as the center and the │Z's-Zzd│

as the radius. The region of operation is in the quadrant 1 but the measured impedance –Zk is

always in the quadrant 3, so the DPFC distance element will not operate and have the definite

directionality.

Note!

The DPFC distance protection can be enabled or disabled by corresponding logic setting

and binary input. Please refer to section 8.4.

3.5 Current Differential Protection

3.5.1 Application

Current differential protection can be used as main protection of EHV and HV overhead line or

cable. It includes phase-segregated current differential protection and zero-sequence current

differential protection.

Current differential protection exchanges information among ends by optical fibre channel. The


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protection device can flexibly select dedicated optical fibre channel or multiplex channel. The

protection device can calculate channel delay in real time, and adjust sample instant to ensure

synchronism sampling of each end based on channel delay. The channel delay is calculated on

the premise that the routine of both directions (receiving and sending) shall be same to each other.

The communication rate used by protection device is 2048kbit/s. The maximum one-way channel

propagation delay is 20ms. A transfer trip and two transfer signals can be transmitted to the

remote end to fulfill some auxiliary functions via a communication channel.

Through capacitive current compensation, the sensitivity of current differential protection is

improved. Because capacitive current compensation depends on voltage, capacitive current

compensation will be disabled automatically if no voltage is input or VT circuit fails.

3.5.2 Function Description

Based on channel supervision function, the protection device can automatically record temporal

channel status if the channel fails which will block current differential protection automatically. The

detailed channel status, including channel delay, current from the remote end and differential

current, can be display on the LCD.

Current differential protection comprises three elements:

DPFC current differential element

Steady-state current differential element

Zero-sequence differential element

3.5.2.1 DPFC Current Differential Element (Stage 1)

Operation criteria:

⎩⎨⎧

>

×>

HDiff Φ

BiasΦDiff Φ

IΔIΔI0.75ΔI

Equation 3.5-1

Where:

Diff ΦΔI : The DPFC differential current ( NΦMΦDiff Φ IΔIΔΔI && += )

BiasΦΔI : The DPFC restraint current ( NΦMΦBiasΦ ΔIΔIΔI += )

HI : Max(1.5×[I_Diff],C1L

N

X

1.5U)


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Figure 3.5-1 Operation characteristic of DPFC current differential element (stage 1)

3.5.2.2 DPFC Current Differential Element (Stage 2)

Operation criteria:

⎩⎨⎧

>

×>

QDiff Φ

BiasΦDiff Φ

IΔIΔI0.75ΔI

Equation 3.5-2

Where:

QI : Max([I_Diff],C1L

N

X

1.25U)

Diff ΦΔI and BiasΦΔI are the same as those mentioned above.

IQ

k=0.75

ΔIDiff

ΔIBias

k=1

Figure 3.5-2 Operation characteristic of DPFC current differential element (stage 2)

When the above criterion is met, the stage 2 of DPFC current differential element will operate after


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25ms.

3.5.2.3 Steady-state Current Differential Element (stage 1)

Operation criteria :

⎩⎨⎧

>

×>

HDiff Φ

BiasΦDiff Φ

II

I0.6I Equation 3.5-3

Where:

Diff ΦI : The phase differential current ( NΦMΦDiff Φ III && += )

BiasΦI : The phase restraint current ( NΦMΦBiasΦ III && −= )

HI : Max(1.5×[I_Diff],C1L

N

X

1.5U)

Figure 3.5-3 Operation characteristic of steady-state current differential element (stage 1)

3.5.2.4 Steady-state Current Differential Element (stage 2)

Operation criteria :

⎩⎨⎧

>

×>

MDiff Φ

BiasΦDiff Φ

II

I0.6I Equation 3.5-4

Where:

MI : Max([I_Diff],C1L

N

X

1.25U)

Diff ΦI and BiasΦI are the same as those mentioned above.


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Figure 3.5-4 Operation characteristic of steady-state current differential element (stage 2)

When the above criterion is met, the stage 2 of steady-state differential current relay will operate

after 25ms.

3.5.2.5 Zero-sequence Current Differential Element

Zero-sequence differential current element is sensitive to high resistance ground fault.

operation criteria:

⎪⎪

⎩

⎪⎪

⎨

⎧

>

×>>

×>

MDiff Φ

BiasΦDiff Φ

MDiff0

Bias0Diff0

II

I0.15III

I0.75I

Equation 3.5-5

Where:

Diff0I : The zero-sequence differential current

Diff ΦI : The phase differential current

Bias0I : The zero-sequence restraint current ( N0M0Bias0 III && −= )

MI : [I_Diff]

BiasΦI is the same to those mentioned above


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Figure 3.5-5 Operation characteristic of zero-sequence current differential element

When the above criterion is met, the zero sequence differential current relay will operate after

45ms.

3.5.2.6 Capacitive Current Compensation

For the long transmission line whose capacitance current is very large, in order to increase the

sensitivity of zero-sequence current differential element when a ground fault associated with fault

resistance occurs, capacitance current must be compensated to eliminate the effect that

capacitance current has on differential current. The traditional method of compensating

capacitance current can only compensate steady-state capacitance current. However, during the

transient period, such as closing circuit breaker to no-load line, clearing external fault and so on,

there are large transient capacitance current in the line. The traditional method cannot

compensate the capacitance current completely, hence, a new method is available, which can

compensate transient component of capacitance current.

1. For long transmission line without shunt reactor

Phase capacitance current of line can be derived from “∏” equivalent circuit. For normal operation

condition, closing circuit breaker to no-load line and clearing external fault, not only steady-state

component of capacitance current but also transient component of capacitance current can be

compensated. It can improve the sensitivity of differential protection.

Figure 3.5-6∏ equivalent circuit


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For different system frequency, the capacitance current which is shown in above figure can be

calculated by:

dt

duCi cc = Equation 3.5-6

Where:

ci : Capacitance current flowing through each capacitance

C : Capacitance value

cu : Voltage between both ends of capacitance

Based on the result of above equation, i.e. Equation 3.5-6, capacitance of each phase can be gained.

2. For long transmission line with shunt reactor

Because a part of capacitance current has been compensated by shunt reactor, reactance current

IL must be subtracted from capacitance current calculated by above equation, i.e. Equation 3.5-6.

Figure 3.5-7 Equivalent circuit of shunt reactor

Because the current and voltage of reactor meet the following relation:

dt

(t)diL(t)U-(t)U LPf L = Equation 3.5-7

To perform integral operation for Equation 3.5-7 from t to t-∆t, IL can be calculated by:

[ ]dt(t)U(t)UL

1Δt)-(ti(t)i

t

Δttf L

P

LL ∫ − −+= Equation 3.5-8

Then,

(t)idt

duCi L

cc −= Equation 3.5-9

3. For short transmission line

Because capacitance current is very small, the sensitivity of current differential protection can still


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meet the requirement. The function, capacitance current compensation, will be disabled

automatically if differential current is smaller than 01IN.

3.5.2.7 CT Supervision

If CT circuit failure occurs, delayed alarm will be issued. When CT circuit failure occurs on an end,

the FD and current differential protection on this end might operate at once. However, FD on

another end will not operate and not send any permissive signal of current differential relay.

Therefore, the current differential protection will not maloperate. Meanwhile the healthy end will

issue alarm signal [Alm_Diff_ChA] which will be treated as the same as the alarm [Alm_CTS].

However, if CT circuit failure associated with internal fault or pickup due to system disturbance is

detected, the protective device will show two kinds of behavior.

If logic setting [En_CTSBlkDiff] (differential protection being blocked during CT circuit failure) is set

as “1”, the differential protection will be blocked.

If logic setting [En_CTSBlkDiff] is set as “0” and the differential current of the faulty phase is more

than the differential current setting [I_Diff_CTS] during CT circuit failure, the differential protection

will operate with alarm signal being issued at the same time.

3.5.2.8 CT Saturation

The incorrect operating of current differential protection would occur due to transient CT saturation

at the moment when external fault occurs. Hence, the protective device adopts high restraint

coefficient and self-adaptive floating restraint threshold, which can prevent current differential

protection from mal-operation even in serious saturation case.

3.5.2.9 Synchronous Sampling

One of the protection devices on both ends is set as reference end (the end whose ID code is

greater, [ID_Local]>[ID_Remote]) and normally called “master”; the device on the other end is set

as synchronous end (the end whose ID code is smaller, [ID_Local]


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message. Side S will receive the message from side M at the time “tsr” and obtain “tms-tmr”.

Therefore, we can obtain the time delay of the channel “Td” through calculation:

2

)t(t)t(tT mr mssssr d

−−−=

Figure 3.5-8 Calculation schematic diagram of channel time delay

2. Measure the sampling time error of the protection devices on both ends through the slave and

adjust the slave’s time of sampling pulse according to the time delay of the channel, to realize

synchronous sampling.

The master implements the sampling in fixed interval “Tsm” and meanwhile sends message to the

slave on the basis of internal clock of the protection device. When the slave receives the message

from the master, it can know the sampling time of the master according to the time delay of the

channel and obtain the sampling time error “ΔT” of the protection devices on both ends accordingto its current sampling time. It is shown in Figure 3.5-9. The slave adjusts the next sampling time to

make “ΔT”→0. When ΔT is less than the error, we can think the protection devices on both endsrealize synchronous sampling.

Figure 3.5-9 Schematic diagram for synchronous sampling adjustment

3.5.2.10 Communication Channel Interface

Depending on the difference of the amount of optic fibre core and the distance permitted to


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transmit, the protection device can select two modes including dedicated optical fibre channel and

multiplex channel. The multiplex channel is not recommended unless the receiver power does not

meet the requirement due to too long transmission line.

Dedicated 2048kbit/s channel is shown in Figure 3.5-10, Two fibre cores of optical cable are

dedicated to differential protection

Figure 3.5-10 Application of dedicated 2048kbit/s channel

Multiplex 2048kbit/s channel is shown in Figure 3.5-11.

TX

RXMUX2M

Pig Tail

2048kbit/s

SDH Device

E1Interface

Coaxial cableOptic fibre

communication

net

Differential

ProtectionPig Tail

Figure 3.5-11 Application of multiplex channel

3.5.2.11 Communication Clock

Data exchange is very important to digital differential protection.

The differential relay sends and receives data based on respective clock, which are called transmit

clock (i.e. clock TX) and receive clock (i.e. clock RX) respectively. Clock RX is fixed to be extractedfrom data frame, which can ensure no drop-out data code generated and no receive error data

code received. Clock TX has two options:

1) Use internal crystal clock, which is called internal clock. (master clock)

2) Use clock TX, which is called external clock. (slave clock)

Depend on the difference of the clock used by the differential relays of the two terminals, there are

three modes.

1. Master-master mode

Both ends use internal clock.

2. Slave-slave mode

Both ends use external clock.

3. Master-slave mode

One of them uses internal clock, the other uses external clock. (Not recommended)

Depending on the logic setting [En_InnClock_ChA], current differential protection selects the

communication clock mode. The inner clock is enabled automatically when the logic setting[En_InnClock_ChA] is set as “1”. Contrarily, the outer clock is enabled automatically when the


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logic setting [En_InnClock_ChA] is set to “0”.

If the protection device uses multiplex PCM channel, logic setting [En_InnClock_ChA] at both

ends should be set as “0”. If the protection device uses dedicated optical fibre channel, logic

setting [En_InnClock_ChA] at both ends should be set as “1”.

3.5.2.12 Identity Code

In order to ensure reliability of protection device when digital communication channel is applied,

providing settings [ID_Local] and [ID_Remote] is used as identity code to distinguish uniquely

protection device in the remote end using same channel.

During normal operation, the identity code of protection device in the end should be different with

that of protection device in the remote end. In addition, it should be different with that of protection

device used to protect other transmission line. In one word, identity code of protection device, i.e.,

the setting [ID_Local], should have uniqueness in the power grid. The setting range is from 0 to

65535. Only under the test mode, they can be set as the same.

The end of which setting [ID_Local] should be same as the [ID_Remote] of the other and the

greater [ID_Local] between the two ends is chosen as a master end for sampling synchronism, the

other is a slave end. If the setting [ID_Local] is set as same as [ID_Remote], that means the

equipment in loopback testing state.

The setting [ID_Local] is packaged in the data frame and send to the remote end of line through

channel. When [ID_Local] received by protection device is same to the setting [ID_Remote] of this

protection device, the message received comes from the remote end of line certainly and is valid,

and protection information involved in message is read. When they are not equal, the message is

thought as invalid and protection information involved in message is ignored. corresponding

alarms [Alm_ID_ChA] and [Alm_ChA] will be issued.

3.5.2.13 Channel Statistics

The protection device has the function of channel statistics and can monitor the channel status on

line. The protection device can form a channel statistic report automatically at 9:00 every day and

the report can be printed for operator to understand the channel quality. The monitoring contents

of channel status are shown as follows, and they can be gained by the menu “VALUES→ COMM_CH_STATE”.

1. Beginning time, [Time_Start]

It shows the starting time of the channel status statistics of the protection device in the local end.

2. Master-slave mode of local device [Equip_Local]

It shows that local protection device is master or slave.

3. ID code of the remote end, [ID_Remote_ChA]

It shows the ID information received by the device on this end under present conditions.

4. Time delay of channel A, [t_Dly_ChA]


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It shows the calculated data of the channel time delay of the protection device on this end under

present conditions. (unit:us)

5. Total amount of error frame of channel A, [N_CrcFail_ChA]

It shows the total numbers of the wrong frames of the device on this end from starting time of

channel statistics till now. (the maximum is 65535, counted again from 0 if beyond 65535)

Error frame means that this frame fails in CRC check.

6. Total amount of abnormal messages of channel A, [N_FrameErr_ChA]

It shows the total numbers of abnormal messages of the device on this end from starting time of


7. Total amount of loss frames of channel A, [N_FrameLoss_ChA]

It shows the total numbers of the invalid frames of the device on this end from starting time of


8. Total amount of abnormal messages from the remote end of channel A,

[N_RemoteAbnor_ChA]

It shows the total numbers of abnormal messages received from the remote end from starting time

of channel statistics till now. (the maximum is 65535, counted again from 0 if beyond 65535)

9. Seconds of serious error frames of channel A, [t_Second_CrcFail_ChA]

It shows the total numbers of seriously error frame seconds of the protection device on this side

from starting time of the channel statistics till now. (the maximum is 65535, counted again from 0 ifbeyond 65535)

10. Desynchronizing times of channel A, [N_LossSyn_ChA]

It shows the desynchronizing times of the protection device on this end from starting time of



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3.5.3 Logic Scheme

3.5.3.1 Common Element

Where:

DIFF Enable (Local end): local current differential protection is enabled

DIFF Enable (Remote end): remote current differential protection is enabled

Common differential condition (A)

Common differential condition (B)

Common differential condition (C)

IDiff >0.15×IBias (A)

IDiff >0.15×IBias (B)

IDiff >0.15×IBias (C)

IDiff >[I_Diff] (A)

IDiff >[I_Diff] (B)

IDiff >[I_Diff] (C)

&

&

&

Where:

IDiff : differential current

IBias: restraint current

A: phase A

B: phase B

C: phase C


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Differential condition 1 (A)

Differential condition 1 (B)

Differential condition 1 (C)

Common differential condition (A)

Common differential condition (B)

Common differential condition (C)

Idiff>[I_Diff_CTS]

[En_CTSBlkDiff ]

[Alm_Diff_ChA]

DIFF Enable (Local end)

DIFF Enable (Remote end)

>=1

&

>=1

&

&

&

&

CT circuit failure

&

When binary input [EBI_DiffP], virtual binary input [VEBI_DiffP] and logic setting [En_DiffP_ChA]are all set as “1”, the signal “DIFF Enable” is valid. They can be visible or invisible in the protection

device through configuration based on different project. If they are invisible, the signal “DIFF

Enable (Local end)” is valid by default.

The signal “DIFF Enable (Remote end)” is an information from the remote end via optical fibre

channel, which is used to indicate whether current differential protection in the remote end is

enabled or not.


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3.5.3.2 DPFC Differential Element (stage 1)

DPFC DIFF1 (A)

DPFC DIFF1 (B)

DPFC DIFF1 (C)




[En_DPFC_Diff1]

Op_DPFC_Diff1 (A)

Op_DPFC_Diff1 (B)

Op_DPFC_Diff1 (C)

&

&

&

Op_DPFC_Diff1 (A)

Op_DPFC_Diff1 (B)

Op_DPFC_Diff1 (C)

>=1

Op_DPFC_Diff1

Where:

DPFC DIFF1: stage 1 of DPFC differential element

3.5.3.3 DPFC Differential Element (stage 2)

DPFC DIFF2 (A)

DPFC DIFF2 (B)

DPFC DIFF2 (C)




[En_DPFC_Diff2]

Op_DPFC_Diff2 (A)

Op_DPFC_Diff2 (B)

Op_DPFC_Diff2 (C)

25ms 0ms

25ms 0ms

25ms 0ms

&

&

&

Op_DPFC_Diff2 (A)

Op_DPFC_Diff2 (B)

Op_DPFC_Diff2 (C)

>=1Op_DPFC_Diff2

Where:

DPFC DIFF2: stage 2 of DPFC differential element


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3.5.3.4 Steady-state Differential Element (stage 1)

[En_Stdy_Diff1]

Steady-state DIFF1 (A)


Steady-state DIFF1 (B)


Steady-state DIFF1 (C)

Op_Stdy_Diff1 (A)

Op_Stdy_Diff1 (B)

Op_Stdy_Diff1 (C)

&

&

&

Op_Stdy_Diff1 (A)

Op_Stdy_Diff1 (B)

Op_Stdy_Diff1 (C)

>=1

Op_Stdy_Diff1


Where:

Steady-state DIFF1: stage 1 of steady-state differential element

3.5.3.5 Steady-state Differential Element (stage 2)

Steady-state DIFF2 (A)

Steady-state DIFF2 (C)


Steady-state DIFF2 (B)



Op_Stdy_Diff2 (A)

Op_Stdy_Diff2 (B)

Op_Stdy_Diff2 (C)

25ms 0ms

25ms 0ms

25ms 0ms

[En_Stdy_Diff2]

&

&

&

Op_Stdy_Diff2 (A)

Op_Stdy_Diff2 (B)

Op_Stdy_Diff2 (C)

>=1Op_Stdy_Diff2

Where:

Steady-state DIFF2: stage 2 of steady-state differential element


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3.5.3.6 Zero-sequence Differential Element

REF DIFF (A)

REF DIFF (C)


REF DIFF (B)



Op_REF (A)

Op_REF (B)

Op_REF (C)

40ms 0ms

40ms 0ms

40ms 0ms

[En_REF]

&

pcs-931 my instruction manual en general x r1.00 (en xlbh5104.0060.1101)

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