pcs-9611 x instruction manual en overseas general x r1.01 (en dybh5301.0086.0002)

PCS-9611

Feeder Relay

Instruction Manual

NR Electric Co., Ltd.

Preface

PCS-9611 Feeder Relay IDate: 2011-08-29

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 Electric Co., Ltd. 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 chapters 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:

z Are familiar with the installation, commissioning, and operation of the equipment and of the system to which it is being connected;

z 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;

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

z Are trained in emergency procedures (first aid).

Preface

PCS-9611 Feeder Relay II Date: 2011-08-29

Instructions and Warnings

The following indicators and standard definitions are used:

DANGER means that death, severe personal injury, or considerable equipment damage will occur if safety precautions are disregarded.

WARNING means that death, severe personal, or considerable equipment damage could occur if safety precautions are disregarded.

CAUTION 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!

z Exposed terminals Do not touch the exposed terminals of this equipment while the power is on, as the high voltage generated is dangerous.

z Residual voltage Hazardous voltage can be present in the DC circuit just after switching off the power supply. It takes a few seconds for the voltage to discharge.

Preface

PCS-9611 Feeder Relay IIIDate: 2011-08-29

CAUTION!

z Earthing The earthing terminal of the equipment must be securely earthed.

z 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.

z Ratings Before applying AC voltage and current or the power supply to the equipment, check that they conform to the equipment ratings.

z Printed circuit board Do not attach and remove printed circuit boards when the power supply to the equipment is on, as this may cause the equipment to malfunction.

z 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.

z Connection cable Carefully handle the connection cable without applying excessive force.

Typographic and Graphical Conventions

The following symbols are used in drawings:

Input signal of a function block, such as a logic setting, a blocking signal or a analog comparator signal etc.

Input inversion signal of a function block, such as a logic setting, a blocking signal or a analog comparator signal etc.

AND gate: all the input signals are 1, then the output is 1

OR gate: anyone the input signals is 1, then the output is 1

RS flipflop (static memory): setting input (S), resetting input (R), output (Q) and inverted output (Q)

Preface

PCS-9611 Feeder Relay IV Date: 2011-08-29

Timer: pickup with delay t, dropout without delay

Timer: pickup without delay, dropout with delay t

Timer: pickup with delay t1, dropout with delay t2

Junction (connection point)

Copyright

Version: 1.01

P/N: EN_DYBH5301.0086.0002

Copyright NR 2011. 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-9611 Feeder Relay VDate: 2011-08-29

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.

The chapter contents 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 Function

Introduce the management functions (such as metering, control and recording etc.) of this relay.

6 Hardware

Introduce the main function carried out by each module of this relay and providing the definition of pins of each module.

7 Settings

List of all the settings and their ranges and step sizes, together with a brief explanation of each setting 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 the HMI. It also lists all the information which can be view through the HMI, such as settings, measurements, all kinds of reports etc.

9 Configurable Function

Introduce the configurable function (such as protection function configuration, LED configuration, binary input configuration and binary output configuration etc.) of this relay.

10 Communication

Introduce the communication port and protocol which this relay can support, the IEC60870-5-103, IEC61850 and DNP3.0 protocols are introduced in details.

Preface

PCS-9611 Feeder Relay VI Date: 2011-08-29

11 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.

12 Commissioning

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

13 Maintenance

A general maintenance policy for this relay is outlined.

14 Decommissioning and Disposal

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

15 Manual Version History

List the instruction manual version and the modification history records.

1 Introduction

PCS-9611 Feeder Relay 1-aDate: 2011-08-29

1 Introduction

Table of Contents

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

1.2 Functions ..........................................................................................................1-1

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

List of Figures

Figure 1.1-1 Functional diagram of PCS-9611 ........................................................................ 1-1

1 Introduction

PCS-9611 Feeder Relay 1-b Date: 2011-08-29

1 Introduction

PCS-9611 Feeder Relay 1-1Date: 2011-08-29

1.1 Application

The PCS-9611 relay is a protection, control and monitoring unit for various primary equipments (such as overhead line, underground cable and transformer etc.) on solidly grounded, impedance grounded, Peterson coil grounded and ungrounded system. This relay is suitable for wall surface mounted indoors or outdoors or flush mounted into a control panel.

This relay can sample the analog values from the traditional instrument transformers, or receive the sampled values from the electronic current and voltage transformers (via a merging unit). The binary inputs and outputs of this relay can be configured according to the demands of a practical engineering through the PCS-PC configuration tool auxiliary software, which can meet some special requirements of protection and control functions.

This relay can fully support the IEC61850 communication protocol and GOOSE function, and can completely meet the demands of a modern digitalized substation.

The function diagram of this relay is shown in Figure 1.1-1.

Figure 1.1-1 Functional diagram of PCS-9611

1.2 Functions

The functions of this relay include protective functions, management functions and auxiliary testing functions, and the functions of this relay are listed in the following tables.

z Protective functions

1 Introduction

PCS-9611 Feeder Relay 1-2 Date: 2011-08-29

Protective Functions

50P Instantaneous overcurrent protection

51P Time overcurrent protection

67P Directional overcurrent protection

50G Instantaneous zero sequence overcurrent protection

51G Time zero sequence overcurrent protection

67G Directional zero sequence overcurrent protection

51SG Sensitive earth fault protection

67SG Directional sensitive earth fault protection

27 Undervoltage protection

59 Overvoltage protection

47 Negative sequence overvoltage protection

59G Zero sequence overvoltage protection

49 Thermal overload protection

46 Negative sequence overcurrent protection

46BC Broken conductor protection

81U Under-frequency protection

81O Over-frequency protection

81R Frequency rate-of-change protection

50BF Breaker failure Protection

79 Three-pole auto-recloser (Up to 4 shots)

25 Synchronism check function

SOTF Switch onto fault logic

MR Mechanical protection

AI Analog inputs

Voltage and current drift auto adjustment

Self supervision

VTS Voltage transformer supervision

CTS Current transformer supervision

Binary inputs

Binary outputs

z Management functions Management Functions

Metering

Circuit breaker status monitoring

2 Circuit breaker control

TCS Tripping circuit supervision

Multiple setting groups

Control inputs

64 Protection operation reports

1024 Supervision alarm records

1024 Control operation records

1 Introduction


1024 User operation records

FDR 64 Fault and disturbance records

SOE

1024 latest SOE records, latest records of the following elements

state changing: operating abnormality alarm elements, supervision

alarm elements, protection elements and binary input elements.

Rear communication ports: Ethernet, RS-485, Printer port

Time synchronization port: RS-485

z Auxiliary testing functions Auxiliary Testing Functions

Virtual tripping report generation and communication testing

Virtual self-supervision report generation and communication testing

Virtual binary input state change report generation and communication testing

Virtual metering values generation and communication testing

1.3 Features

z This device is based on a 32-bit high performance dual-core processor, internal high speed bus and intelligent I/O ports, and the hardware is in module design and can be configured flexibly, featuring interchangeability and easy extension and maintenance.

z Modularized hardware design makes this relay be easily upgraded or repaired by a qualified service person. Various function optional modules can satisfy various situations according to the different requirements of the users.

z The adoption of 16-bit A/D converter and the dual-channel sampling technology can ensure the accuracy and reliability of protection sampling and the correctness of protection operation. It is also provides dedicated current transformers for metering, and ensures the high accuracy of telemetering with 48-point high speed sampling rate per cycle.

z This device can sample the analog values from the traditional instrument transformers, or receive the sampled values from the electronic transformers. It can support the protocol IEC60044-8, IEC61850-9-2 and GOOSE.

z Various algorithms for protection and measurement have been completed in this device for the feature of electronic transformer sampling, such as the error prevention method of multi-algorithms data anomaly for the digital channels, to realize high accuracy and reliability under various conditions of network faults or communication interruption.

z This device has powerful GOOSE functions, and the connection and cooperation between some devices can be realized without using electrical cables, to facilitate the realization of such functions as simple bus differential protection, overload interlock shedding function and backup automatic transfer function etc.

z This device has fully realized the technology to integrate six functions into one device: protection, measurement, control, remote signaling, merging unit function and remote module

1 Introduction


functions, to improve the reliability.

z Various methods of GPS time synchronization are supported in this relay, including SNTP, IEEE1588 (V2), pulse per second (PPS) and IRIG-B synchronization.

z The protection modules are completely separated from other modules, and are independent in both hardware and software. The protection functions do not depend on the communication network, so the failure of communication network will not affect the normal operation of the protection functions.

z Mature protection configuration, fast speed and high security performance can meet the practical requirements. Each protective element is independent, so it is very convenient for whether adopting the selected protective element.

z This device constantly measures and calculates a large amount of analog quantities, such as phase voltage, phase-to-phase voltage, neutral voltage, phase current, neutral current, active power, reactive power, power factor and frequency etc.

z The human machine interface (HMI) with a small control module (a 240128-dot LCD, a 9-key keypad and 20 LED indicators) on the front panel is very friendly and convenient to the user.

z This device can communicate with a SAS or RTU via different communication intermediates: Ethernet network, RS-485 serial ports. The communication protocol of this device is optional: IEC61850, IEC60870-5-103 or DNP3.0.

z This device can detect the tripping circuit of the circuit breaker and monitor the operation (close or trip) time of a circuit breaker by checking the auxiliary contacts of the circuit breaker.

z Complete event recording function is provided: 64 latest protection operation reports, 1024 latest supervision records, 1024 latest control operation records, 1024 latest user operation records and 1024 latest records of time tagged sequence of event (SOE) can be recorded.

z Powerful fault and disturbance recording function is supported: 64 latest fault or disturbance waves, the duration of a wave recording is configurable.

2 Technical Data


2 Technical Data

Table of Contents

2.1 General Specification.......................................................................................2-1

2.1.1 Electrical Specifications ..................................................................................................... 2-1

2.1.2 Mechanical Specifications.................................................................................................. 2-2

2.1.3 Ambient Temperature and Humidity ................................................................................... 2-2

2.1.4 Communication Interfaces ................................................................................................. 2-3

2.1.5 Type Test ........................................................................................................................... 2-4

2.2 Protective Functions........................................................................................2-6

2.2.1 Overcurrent Protection....................................................................................................... 2-6

2.2.2 Voltage Control Element .................................................................................................... 2-6

2.2.3 Phase Directional Element................................................................................................. 2-6

2.2.4 IDMT Overcurrent Protection ............................................................................................. 2-6

2.2.5 Zero Sequence Overcurrent Protection ............................................................................. 2-6

2.2.6 Zero Sequence Directional Element .................................................................................. 2-7

2.2.7 Zero Sequence IDMT Overcurrent Protection.................................................................... 2-7

2.2.8 Sensitive Earth Fault Protection......................................................................................... 2-7

2.2.9 Sensitive Earth Fault Directional Element.......................................................................... 2-7

2.2.10 Sensitive Earth Fault IDMT Protection ............................................................................. 2-8

2.2.11 Negative Sequence Overcurrent Protection..................................................................... 2-8

2.2.12 Thermal Overload Protection ........................................................................................... 2-8

2.2.13 Undervoltage Protection .................................................................................................. 2-8

2.2.14 Overvoltage Protection .................................................................................................... 2-9

2.2.15 Zero Sequence Overvoltage Protection ........................................................................... 2-9

2.2.16 Negative Sequence Overvoltage Protection .................................................................... 2-9

2.2.17 Frequency Protection....................................................................................................... 2-9

2.2.18 Frequency Rate-of-change Protection ........................................................................... 2-10

2.2.19 SOTF Overcurrent Protection ........................................................................................ 2-10

2 Technical Data


2.2.20 Zero Sequence SOTF Overcurrent Protection ...............................................................2-10

2.2.21 Breaker Failure Protection..............................................................................................2-10

2.2.22 Broken Conductor Protection ......................................................................................... 2-11

2.3 Management Functions................................................................................. 2-11

2.3.1 Metering Scope and Accuracy.......................................................................................... 2-11

2.3.2 Control Performance ........................................................................................................ 2-11

2.3.3 Clock Performance...........................................................................................................2-12

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

2.3.5 Binary Input Signal ...........................................................................................................2-12

2.3.6 Transient Overreach.........................................................................................................2-12

2.4 Certification.................................................................................................... 2-12

2 Technical Data


2.1 General Specification

2.1.1 Electrical Specifications

2.1.1.1 Power Supply

Standard IEC60255-11: 2008

Rated voltage 110/125Vdc, 220/250Vdc, 220Vac

Variation 80% ~ 120%

Permissible ripple voltage Max 15% of the rated voltage (DC power supply)

Traditional AC inputs < 10W @ Quiescent condition; < 15W @ Operating condition Burden

Digital AC inputs < 15W @ Quiescent condition; < 20W @ Operating condition

2.1.1.2 Analog Current Input Ratings

Phase rotation ABC

Rated frequency (fn) 50Hz, 60Hz

Nominal range fn 5Hz

Application object For protection For metering

Rated current (In) 1A 5A 1A 5A

Linear to 30In 30In 2In 2In

continuously 3In 3In 2In 2In

for 10s 30In 30In 12In 12In

for 1s 100In 100In 30In 30In

Thermal

withstand

capability for half a cycle 250In 250In 75In 75In

Burden (@ In) < 0.10VA/phase < 0.20VA/phase < 0.20VA/phase < 0.40VA/phase

2.1.1.3 Analog Voltage Input Ratings

Phase rotation ABC

Rated frequency (fn) 50Hz, 60Hz

Nominal range fn 5Hz

Rated voltage (Un) 100V ~ 130V (phase-to-phase voltage)

Linear to 130V

continuously 130V

10s 200V

Thermal

withstand

capability 1s 250V

Burden < 0.10VA / phase

2.1.1.4 Binary Input

Binary input number Up to 38

Rated voltage 24V 48V 110V 125V 220V 250V

Rated current 1.20mA 2.40mA 1.10mA 1.25mA 2.20mA 2.50mA

Pickup voltage 55% ~ 70% rated voltage

Dropout voltage 55% rated voltage

2 Technical Data


Maximum permitted voltage 120% rated voltage

High voltage withstand 2000Vac, 2800Vdc

Resolving time for logic input < 1ms

2.1.1.5 Binary Output

Item Tripping output Signal output

Binary output number Up to 25 Up to 10

Output model Potential-free contact Potential-free contact

Max system voltage 380Vac, 250Vdc 380Vac, 250Vdc

Voltage across open contact 1000V RMS for 1min 1200V RMS for 1min

Continuous carry 5.0A @ 380Vac; 5.0A @ 250Vdc 8.0A @ 380Vac; 8.0A @ 250Vdc

Short duration current 6A for 3000ms; 15A for 500ms 10A for 3000ms; 20A for 500ms

Breaking capacity

0.6A @ 48Vdc, L/R=40ms

0.1A @ 110Vdc, L/R=40ms

0.05A @ 220Vdc, L/R=40ms

0.6A @ 48Vdc, L/R=40ms

0.3A @ 110Vdc, L/R=40ms

0.2A @ 220Vdc, L/R=40ms

Pickup time < 8ms < 10ms

Dropout time < 5ms < 8ms

Bounce time 1ms 1ms

loaded contact 100,000 operations minimum 100,000 operations minimum Durability

unloaded contact 10,000,000 operations minimum 10,000,000 operations minimum

2.1.2 Mechanical Specifications

Enclosure dimensions 225.00177.00224.80 (WHD, unit: mm)

Trepanning dimensions 226.00178.00, M5 screw (WH, unit: mm)

Mounting way Flush mounted

Weight per device Approx. 7.0kg (fully equipped)

Local control panel Small control module: a 240128-dot LCD, a 9-key keypad and 20 LEDs

Display language Optional: Chinese, English

Housing material Aluminum

Housing color Silver grey

Location of terminals Rear panel of the device

Protection class IEC60225-1: 2009

Front side: IP40, up to IP51

Rear side, connection terminals: IP20

Other Sides: IP30

2.1.3 Ambient Temperature and Humidity

Standard IEC60225-1: 2009

Operating temperature range -40C ~ +70C

Transport and storage temperature range -40C ~ +70C

Permissible humidity 5% ~ 95%, condensation not permissible

Altitude < 3000m

2 Technical Data


2.1.4 Communication Interfaces

2.1.4.1 Ethernet Port for RTU/SCADA

Medium Parameters

Port number 2 or 4

Connector type RJ-45

Transmission rate 100Mbits/s

Transmission standard 100Base-TX

Transmission distance < 100m

Protocol IEC60870-5-103:1997 or IEC61850

Electrical

Safety level Isolation to ELV level

Port number 2

Connector type SC


Transmission standard 100Base-FX

Optical fiber type Multi-mode

Wavelength 1300nm


Ethernet

Optical

Protocol IEC60870-5-103:1997 or IEC61850

2.1.4.2 Serial Port for RTU/SCADA

Medium Parameters

Port number 0 or 2

Baud rate 4800 ~ 115200bps

Transmission distance < 1000m @ 4800bps

Maximal capacity 32

Protocol IEC60870-5-103:1997 or DNP3.0

RS-485 (EIA)


2.1.4.3 Serial Port for Printer

Medium Parameters

Port number 1

Baud rate 4800 ~ 115200bps

Printer type EPSON LQ-300K RS-232 (EIA)


2.1.4.4 Serial Port for Time Synchronization

Medium Parameters

Port number 1


Maximal capacity 32

Timing standard PPS, IRIG-B

RS-485 (EIA)


2 Technical Data


2.1.4.5 Ethernet Port for Debugging

Medium Parameters

Port number 1

Connector type RJ-45


Transmission standard 100Base-TX


Electrical Ethernet

(in front panel)


2.1.4.6 Process Level Interface

Medium Parameters

Optical fiber material Glass fiber

Optical fiber type Multi-mode

Connector type LC ST

Wavelength 1310nm 820nm


Minimum transmission power -20dBm

Optical Ethernet

Reception sensitivity -30dBm

2.1.5 Type Test

2.1.5.1 Environmental Tests

Dry cold test IEC60068-2-1: 2007, 16h at -25C

Dry heat test IEC60068-2-2: 2007, 16h at +55C

Damp heat test IEC60068-2-78: 2001, 10 days, 93%RH, +55C

Cyclic temperature with

humidity test

IEC60068-2-30: 2005, six (12+12hours) cycles, 95%RH,

low temperature +25C, high temperature +55C

2.1.5.2 Electrical Tests

Dielectric test IEC60255-27: 2005, test voltage: 2kV, 50Hz, 1min

Impulse voltage test IEC60255-5: 2000, test voltage: 5kV, unipolar impulses, waveform 1.2/50s,

source energy 0.5J

Overvoltage category IEC60255-5: 2000, Class III

Insulation measurement IEC60255-5: 2000, insulation resistance >100M @ 500Vdc

Pollution degree IEC60225-1: 2009, Class II

2.1.5.3 Electromagnetic Compatibility

1MHz burst disturbance tests

- Common mode

- Differential mode

IEC60255-22-1: 2007, Class III

2.5kV

1.0kV

Electrostatic discharge tests

- For contact discharge

- For air discharge

IEC60255-22-2: 2008, Class IV

8.0kV

15.0kV

2 Technical Data


Radio frequency interference tests

- Frequency sweep

- Radiated amplitude-modulated

- Spot frequency

- Radiated amplitude-modulated

- Radiated pulse-modulated

IEC60255-22-3: 2007, Class III

10V/m(RMS), f=801000MHz

10Vm(RMS), f=80/160/450/900MHz

10Vm(RMS), f=900MHz

Fast transient disturbance tests

- Power supply, I/O & Earth terminals

- Communication terminals

IEC60255-22-4: 2008, Class IV

4kV, 2.5kHz, 5/50ns

2kV, 5.0kHz, 5/50ns

Surge immunity tests

- Power supply, AC inputs, I/O terminals

IEC60255-22-5: 2008, Class IV

1.2/50us,

4kV, line-to-ground

2kV, line-to-line

Conducted RF electromagnetic disturbance

- Power supply, AC, I/O, Comm. terminals

IEC60255-22-6: 2001, Class III

10V(RMS), 150kHz~80MHz

Power frequency field immunity IEC60255-22-7: 2003, Class A

10s

300V, line-to-ground

150V, line-to-line

Conducted emission limits IEC60255-25: 2000, Class A

Radiated emission limits IEC60255-25: 2000, Class A

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

Power frequency magnetic field immunity IEC61000-4-8: 2001, Class V

100A/m for 1min

1000A/m for 3s

Pulse magnetic field immunity IEC61000-4-9: 2001, Class V

6.4/16us, 1000A/m for 3s

Damped oscillatory magnetic field immunity IEC61000-4-10: 2001, Class V

100kHz & 1MHz 100A/m

Ring wave immunity

- Power supply, I/O terminals

IEC61000-4-12: 2006, Class III

1MHz

2kV, line-to-ground

1kV, line-to-line

2.1.5.4 Mechanical Tests

Vibration test IEC60255-21-1:1988, Class I

Shock test IEC60255-21-2:1988, Class I

Bump test IEC60255-21-2:1988, Class I

Seismic test IEC60255-21-3:1988, Class I

2 Technical Data


2.2 Protective Functions

2.2.1 Overcurrent Protection

Current setting 0.05In ~ 30.0In

Pickup current 1.00Setting

Dropout current 0.95Setting

Tolerance of current setting 2.5% Setting or 0.01In, whichever is greater

Time setting 0.00s ~ 100.00s

Pickup time 35ms

Dropout time 35ms

Tolerance of time setting 1% Setting + 35ms

2.2.2 Voltage Control Element

Negative overvoltage element setting 2.00V ~ 70.00V

Undervoltage element setting 2.00V ~ 120.00V

Tolerance of voltage setting 2.5% Setting or 0.10V, whichever is greater

Operating time 35ms

2.2.3 Phase Directional Element

Directionality Optional: Forward, Reverse

Characteristic angle Configurable: -180~179, step is 1

Boundary and angle accuracy 3

Block logic Permission or block selectable by setting

Operating time 35ms

2.2.4 IDMT Overcurrent Protection

Current threshold setting 0.05In ~ 4.0In



Tolerance of current threshold setting 2.5% Setting or 0.01In, whichever is greater

Time multiplier setting 0.05 ~ 100.00

Pickup time 35ms

Dropout time 35ms

Tolerance of trip time for 1.2 < I/Ip < 30 5% of reference (calculated) value + 2.5% current

tolerance or 35ms, whichever is greater

2.2.5 Zero Sequence Overcurrent Protection





2 Technical Data



Pickup time 35ms

Dropout time 35ms


2.2.6 Zero Sequence Directional Element





Operating time 35ms

2.2.7 Zero Sequence IDMT Overcurrent Protection

Current threshold setting 0.05In ~ 4.0In



Tolerance of current threshold setting 2.5% Setting or 0.01In, whichever is greater


Pickup time 35ms

Dropout time 35ms



2.2.8 Sensitive Earth Fault Protection

Current setting 0.005A ~ 0.400A, dedicated CT



Tolerance of current setting 1.5% Setting or 1mA, whichever is greater


Pickup time 35ms

Dropout time 35ms


2.2.9 Sensitive Earth Fault Directional Element





Operating time 35ms

2 Technical Data


2.2.10 Sensitive Earth Fault IDMT Protection

Current threshold setting 0.005A ~ 0.400A, dedicated CT



Tolerance of current threshold setting 1.5% Setting or 1mA, whichever is greater


Pickup time 35ms

Dropout time 35ms



2.2.11 Negative Sequence Overcurrent Protection






Pickup time 50ms

Dropout time 50ms


2.2.12 Thermal Overload Protection

Reference current setting 0.05In ~ 3.0In



Tolerance of reference current setting 2.5% Setting or 0.01In, whichever is greater

Time constant setting 0.01s ~ 6000.00s

Pickup time 35ms

Dropout time 35ms

Tolerance of trip time for 1.2 < I/(kIb) < 20 5% of reference (calculated) value + 2.5% current


2.2.13 Undervoltage Protection

Voltage setting 2.00V ~ 120.00V

Pickup voltage 1.00Setting

Dropout voltage Configurable: 1.03Setting ~ 3.00Setting



Pickup time 80ms

Dropout time 80ms


2 Technical Data


2.2.14 Overvoltage Protection



Dropout voltage Configurable: 0.93Setting ~ 0.97Setting



Pickup time 50ms

Dropout time 50ms


2.2.15 Zero Sequence Overvoltage Protection



Dropout voltage 0.95Setting

Tolerance of voltage setting 2.5% or 0.10V, whichever is greater


Pickup time 50ms

Dropout time 50ms


2.2.16 Negative Sequence Overvoltage Protection



Dropout voltage 0.95Setting

Tolerance of voltage setting 2.5% or 0.10V, whichever is greater


Pickup time 50ms

Dropout time 50ms


2.2.17 Frequency Protection

Under-frequency setting 45.00Hz ~ 60.00Hz

Over-frequency setting 50.00Hz ~ 65.00Hz

Pickup frequency 1.00Setting

Dropout frequency 1.00Setting

Tolerance of frequency setting 0.01Hz


Pickup time 50ms

Dropout time 50ms


Blocking element

Undervoltage blocking setting 10.00V ~ 120.00V

2 Technical Data


Operating time 35ms

Tolerance of undervoltage blocking setting 2.5% Setting or 0.10V, whichever is greater

2.2.18 Frequency Rate-of-change Protection

Frequency Rate-of-change setting -10.00Hz/s ~ 10.00Hz/s

Pickup frequency rate-of-change 1.00Setting

Dropout frequency rate-of-change 1.00Setting

Tolerance of frequency rate-of-change setting 0.20Hz/s


Pickup time 50ms

Dropout time 50ms


2.2.19 SOTF Overcurrent Protection






Pickup time 35ms

Dropout time 35ms


2.2.20 Zero Sequence SOTF Overcurrent Protection






Pickup time 35ms

Dropout time 35ms


2.2.21 Breaker Failure Protection






Pickup time 35ms

Dropout time 35ms


2 Technical Data


2.2.22 Broken Conductor Protection

I2/I1 Ratio setting 0.10 ~ 1.00

Pickup ratio 1.00Setting

Dropout ratio 0.95Setting

Tolerance of current setting 2.5% Setting


Pickup time 70ms

Dropout time 70ms


2.3 Management Functions

2.3.1 Metering Scope and Accuracy

Metering Item Range Accuracy

Phase range 0 ~ 360 0.5% or 1

Frequency 35.00Hz ~ 70.00Hz 0.01Hz

Currents from dedicated metering current transformers

Current 0.05 ~ 1.40In 0.2% of reading

Voltage 0.05 ~ 1.40Un 0.5% of reading

Active power (W) 0.20 ~ 1.40Un, 0.05 ~ 1.40In 0.5% of reading at unity power factor

Reactive Power (Vars) 0.20 ~ 1.40Un, 0.05 ~ 1.40In 0.5% of reading at zero power factor

Apparent Power (VA) 0.20 ~ 1.40Un, 0.05 ~ 1.40In 0.5% of reading

Energy (Wh) 0.20 ~ 1.40Un, 0.05 ~ 1.40In 0.5% of reading at unity power factor

Energy (Varh) 0.20 ~ 1.40Un, 0.05 ~ 1.40In 0.5% of reading at zero power factor

Currents from protection measurement current transformers

Current 0.05 ~ 1.40In 2.0% of reading

Voltage 0.05 ~ 1.40Un 0.5% of reading

Active power (W) 0.20 ~ 1.40Un, 0.05 ~ 1.40In 3.0% of reading at unity power factor

Reactive Power (Vars) 0.20 ~ 1.40Un, 0.05 ~ 1.40In 3.0% of reading at zero power factor

Apparent Power (VA) 0.20 ~ 1.40Un, 0.05 ~ 1.40In 3.0% of reading

Energy (Wh) 0.20 ~ 1.40Un, 0.05 ~ 1.40In 3.0% of reading at unity power factor

Energy (Varh) 0.20 ~ 1.40Un, 0.05 ~ 1.40In 3.0% of reading at zero power factor

2.3.2 Control Performance

Control mode Local or remote

Accuracy of local control 1s

Accuracy of remote control 3s

2 Technical Data


2.3.3 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

2.3.4 Fault and Disturbance Recording

Magnitude and relative phases 2.5% of applied quantities

Maximum duration 10000 sampled points (24 sampled points per cycle)

Recording position 5 cycles before pickup of trigger element

2.3.5 Binary Input Signal

Resolution of binary input signal 1ms

Binary input mode Potential-free contact

Resolution of SOE 2ms

2.3.6 Transient Overreach

Transient overreach (DC offset) 5% for X/R 100

2.4 Certification

z ISO9001: 2000 z ISO14001: 2004 z OHSAS18001: 1999 z ISO10012: 2003 z CMMI L4 z EMC: 89/336/EEC, EN50263: 2000 z Products safety(PS): 73/23/EEC, EN61010-1: 2001, EN60950: 2002

3 Operation Theory


3 Operation Theory

Table of Contents

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

3.2 Fault Detectors .................................................................................................3-1

3.3 Overcurrent Protection ....................................................................................3-4

3.3.1 Definite Time Overcurrent Protection................................................................................. 3-4

3.3.2 Inverse Definite Minimum Time Overcurrent Protection..................................................... 3-6

3.3.3 Voltage Control Element for Overcurrent Protection .......................................................... 3-8

3.3.4 Directional Element for Overcurrent Protection.................................................................. 3-9

3.3.5 Harmonic Blocking Element for Overcurrent Protection....................................................3-11

3.3.6 Overcurrent Protection Settings....................................................................................... 3-12

3.4 Thermal Overload Protection ........................................................................3-14

3.4.1 Thermal Overload Protection Theory ............................................................................... 3-14

3.4.2 Thermal Overload Protection Settings ............................................................................. 3-16

3.5 Zero Sequence Overcurrent Protection........................................................3-16

3.5.1 Definite Time Zero Sequence Overcurrent Protection ..................................................... 3-16

3.5.2 IDMT Zero Sequence Overcurrent Protection.................................................................. 3-18

3.5.3 Directional Element for Zero Sequence Overcurrent Protection ...................................... 3-19

3.5.4 Harmonic Blocking Element for ROC Protection.............................................................. 3-20

3.5.5 Zero Sequence Overcurrent Protection Settings ............................................................. 3-21

3.6 Sensitive Earth Fault Protection ...................................................................3-24

3.6.1 Definite Time Sensitive Earth Fault Protection................................................................. 3-24

3.6.2 IDMT Sensitive Earth Fault Protection ............................................................................. 3-25

3.6.3 Directional Element for Sensitive Earth Fault Protection ................................................. 3-26

3.6.4 Sensitive Earth Fault Protection Settings......................................................................... 3-27

3.7 Negative Sequence Overcurrent Protection ................................................3-28

3.7.1 Definite Time Negative Sequence Overcurrent Protection............................................... 3-28

3.7.2 IDMT Negative Sequence Overcurrent Protection........................................................... 3-29

3 Operation Theory


3.7.3 Negative Sequence Overcurrent Protection Settings .......................................................3-30

3.8 Broken Conductor Protection....................................................................... 3-31

3.8.1 Broken Conductor Protection Theory ...............................................................................3-31

3.8.2 Broken Conductor Protection Settings..............................................................................3-31

3.9 Breaker Failure Protection ............................................................................ 3-32

3.9.1 Breaker Failure Protection Theory....................................................................................3-32

3.9.2 Breaker Failure Protection Settings ..................................................................................3-34

3.10 Switch Onto Fault (SOTF) Protection......................................................... 3-34

3.10.1 SOTF Protection Theory.................................................................................................3-34

3.10.2 SOTF Protection Settings...............................................................................................3-36

3.11 Cold Load Pickup Logic .............................................................................. 3-36

3.11.1 Cold Load Pickup Logic Theory ......................................................................................3-36

3.11.2 Cold Load Pickup Logic Settings ....................................................................................3-37

3.12 Undervoltage Protection ............................................................................. 3-39

3.12.1 Undervoltage Protection Theory .....................................................................................3-39

3.12.2 Undervoltage Protection Settings ...................................................................................3-40

3.13 Overvoltage Protection ............................................................................... 3-41

3.13.1 Overvoltage Protection Theory .......................................................................................3-41

3.13.2 Overvoltage Protection Settings .....................................................................................3-42

3.14 Zero Sequence Overvoltage Protection..................................................... 3-43

3.14.1 Zero Sequence Overvoltage Protection Theory..............................................................3-43

3.14.2 Zero Sequence Overvoltage Protection Settings............................................................3-44

3.15 Negative Sequence Overvoltage Protection.............................................. 3-44

3.15.1 Negative Sequence Overvoltage Protection Theory.......................................................3-44

3.15.2 Negative Sequence Overvoltage Protection Settings .....................................................3-45

3.16 Frequency Protection .................................................................................. 3-45

3.16.1 Under-frequency Protection............................................................................................3-46

3.16.2 Over-frequency Protection..............................................................................................3-46

3.16.3 Frequency Rate-of-change Protection............................................................................3-47

3.16.4 Frequency Protection Settings .......................................................................................3-48

3 Operation Theory

PCS-9611 Feeder Relay 3-cDate: 2011-08-29

3.17 Auto-recloser ................................................................................................3-51

3.17.1 Auto-recloser Theory...................................................................................................... 3-51

3.17.2 Auto-recloser Ready Conditions .................................................................................... 3-53

3.17.3 Auto-recloser Startup Condition ..................................................................................... 3-54

3.17.4 Auto-recloser Check Mode............................................................................................. 3-55

3.17.5 Auto-recloser Blocking Logic.......................................................................................... 3-57

3.17.6 Auto-recloser Settings.................................................................................................... 3-57

3.18 Manual Closing Function.............................................................................3-59

3.18.1 Manual Closing Theory .................................................................................................. 3-59

3.18.2 Check Mode for Manual Closing Function ..................................................................... 3-60

3.18.3 Manual Closing Function Settings ................................................................................. 3-62

3.19 Mechanical Protection .................................................................................3-63

3.19.1 Mechanical Protection Theory ....................................................................................... 3-63

3.19.2 Mechanical Protection Settings...................................................................................... 3-63

List of Figures

Figure 3.3-1 Demonstration characteristic of the overcurrent protection ........................... 3-5

Figure 3.3-2 Logic diagram of the stage 1 overcurrent protection....................................... 3-5

Figure 3.3-3 Logic diagram of the stage 4 overcurrent protection....................................... 3-7

Figure 3.3-4 Logic diagram of the OC1 phase A voltage control element ........................... 3-9

Figure 3.3-5 Operation characteristic of the OC directional element................................. 3-10

Figure 3.3-6 Logic diagram of the OC1 phase A directional element ................................. 3-10

Figure 3.3-7 Logic diagram of the OC1 phase A harmonic blocking element ....................3-11

Figure 3.4-1 Characteristic curve of the thermal overload model ...................................... 3-15

Figure 3.4-2 Logic diagram of the thermal overload protection ......................................... 3-15

Figure 3.5-1 Logic diagram of the No.1 zero sequence overcurrent protection................ 3-17

Figure 3.5-2 Logic diagram of the No.1 zero sequence IDMT overcurrent protection...... 3-18

Figure 3.5-3 Operation characteristic of the ROC directional element .............................. 3-19

Figure 3.5-4 Logic diagram of the directional element for the No.1 ROC1 protection...... 3-20

Figure 3.5-5 Logic diagram of the No.1 ROC1 harmonic blocking element....................... 3-20

3 Operation Theory

PCS-9611 Feeder Relay 3-d Date: 2011-08-29

Figure 3.6-1 Logic diagram for the stage 1 sensitive earth fault protection ......................3-25

Figure 3.6-2 Logic diagram of the IDMT sensitive earth fault protection ...........................3-25

Figure 3.6-3 Operation characteristic of the SEF directional element ................................3-26

Figure 3.6-4 Logic diagram of the directional element for the stage 1 SEF protection.....3-27

Figure 3.7-1 Logical diagram of the stage 1 NOC protection...............................................3-29

Figure 3.7-2 Logic diagram of the IDMT negative sequence overcurrent protection ........3-30

Figure 3.8-1 Logic diagram of the broken conductor protection ........................................3-31

Figure 3.9-1 Logic diagram of the breaker failure protection ..............................................3-33

Figure 3.9-2 Timing for a typical breaker failure scenario ...................................................3-33

Figure 3.10-1 Logic diagram of the SOTF protection ...........................................................3-35

Figure 3.11-1 Logic diagram of the cold load pickup function ............................................3-37

Figure 3.12-1 Logic diagram of the system lost voltage for the UV1 protection................3-39

Figure 3.12-2 Logic diagram of the stage 1 undervoltage protection .................................3-40

Figure 3.13-1 Logic diagram of the stage 1 overvoltage protection ...................................3-42

Figure 3.14-1 Logic diagram of the stage 1 ROV protection................................................3-43

Figure 3.15-1 Logic diagram of the NOV protection.............................................................3-45

Figure 3.16-1 Logic diagram of the stage 1 under-frequency protection ...........................3-46

Figure 3.16-2 Logic diagram of the stage 1 over-frequency protection..............................3-47

Figure 3.16-3 Logic diagram of the stage 1 frequency rate-of-change protection.............3-47

Figure 3.17-1 Timing diagram for a successful second reclosing ......................................3-52

Figure 3.17-2 Timing diagram for an unsuccessful one-shot reclosing .............................3-52

Figure 3.17-3 Logic diagram of the auto-recloser ................................................................3-53

Figure 3.17-4 Logic diagram of the auto-recloser ready conditions...................................3-54

Figure 3.17-5 Logic diagram of the synchronism check element for AR ...........................3-55

Figure 3.17-6 Logic diagram of the dead check element for AR .........................................3-56

Figure 3.18-1 Logic diagram of the manual closing function ..............................................3-59

Figure 3.18-2 Logic diagram of the synchronism check element for manual closing.......3-60

Figure 3.18-3 Logic diagram of the dead check element for manual closing ....................3-61

Figure 3.19-1 Logic diagram of the No.1 mechanical protection ........................................3-63

3 Operation Theory


3.1 Overview

The PCS-9611 relay is a microprocessor based relay which can provide mature protection for various primary equipments (such as overhead line, underground cable and transformer etc.). The following sections detail the individual protection functions of this relay.

NOTE! In each functional element, the signal input [XXXX.En1] is used for inputting the

enabling signals; and the signal input [XXXX.Blk] is used for inputting the blocking signals. The XXXX is the name code of the functional element (such as 50/51P1, 49, 50/51G2 etc.). They can be configured through PCS-PC configuration tool auxiliary software. If the signal input [XXXX.En1] is not used, its default value is 1; and if the signal input [XXXX.Blk] is not used, its default value is 0.

3.2 Fault Detectors

The fault detector will operate if any of the following conditions is satisfied.

1. The startup conditions of the auto-recloser are satisfied if the auto-recloser is enabled and ready for operating.

2. Any one of the phase currents is in excess of the setting of the stage 1 overcurrent protection multiplied by 0.95 if the stage 1 overcurrent protection is enabled.




6. The No.1 zero sequence current is in excess of the setting of the stage 1 of the No.1 zero sequence overcurrent protection multiplied by 0.95 if the stage 1 of the No.1 zero sequence overcurrent protection is enabled.




3 Operation Theory






14. The negative sequence current is in excess of the setting of the stage 1 negative sequence overcurrent protection multiplied by 0.95 if the stage 1 negative sequence overcurrent protection is enabled.

15. The negative sequence current is in excess of the setting of the stage 2 negative sequence overcurrent protection multiplied by 0.95 if the stage 2 negative sequence overcurrent protection is enabled.

16. The sensitive earth fault current is in excess of the current setting of the stage 1 sensitive earth fault protection multiplied by 0.95 if the stage 1 sensitive earth fault protection is enabled.




20. Any one of the phase currents is in excess of the setting of the SOTF overcurrent protection multiplied by 0.97 if the SOTF overcurrent protection is enabled.

21. The No.1 zero sequence current is in excess of the setting of the zero sequence SOTF overcurrent protection multiplied by 0.97 if the zero sequence SOTF overcurrent protection is enabled.

22. Any one of the phase currents is in excess of [49.K_Trp][49.Ib_Set] if the thermal overload protection is enabled.

23. The ratio of negative to positive phase sequence current (I2/I1) is in excess of the ratio setting

3 Operation Theory


of the broken conductor protection multiplied by 0.95 if the broken conductor protection is enabled.

24. Any one of the initiation signals of the breaker failure protection is detected if the breaker failure protection is enabled.

25. The voltages are less than the setting of the stage 1 undervoltage protection multiplied by the dropout coefficient setting of the stage 1 undervoltage protection if the stage 1 undervoltage protection is enabled.

26. The voltages are less than the setting of the stage 2 undervoltage protection multiplied by the dropout coefficient setting of the stage 2 undervoltage protection if the stage 1 undervoltage protection is enabled.

27. The voltages are greater than the setting of the stage 1 overvoltage protection multiplied by the dropout coefficient setting of the stage 1 overvoltage protection if the stage 1 overvoltage protection is enabled.

28. The voltages are greater than the setting of the stage 2 overvoltage protection multiplied by the dropout coefficient setting of the stage 2 overvoltage protection if the stage 2 overvoltage protection is enabled.

29. The zero sequence voltage is greater than the setting of the stage 1 zero sequence overvoltage protection multiplied by 0.95 if the stage 1 zero sequence overvoltage protection is enabled.

30. The zero sequence voltage is greater than the setting of the stage 2 zero sequence overvoltage protection multiplied by 0.95 if the stage 2 zero sequence overvoltage protection is enabled.

31. The negative sequence voltage is greater than the setting of the negative sequence overvoltage protection multiplied by 0.95 if the negative sequence overvoltage protection is enabled.

32. The frequency is less than the setting of the stage 1 under-frequency protection and all the phase-to-phase voltages are greater than the voltage setting of the voltage blocking element of the frequency protection if the stage 1 under-frequency protection is enabled and ready for operating.



35. The frequency is less than the setting of the stage 4 under-frequency protection and all the

3 Operation Theory


phase-to-phase voltages are greater than the voltage setting of the voltage blocking element of the frequency protection if the stage 4 under-frequency protection is enabled and ready for operating.

36. The frequency is greater than the setting of the stage 1 over-frequency protection and all the phase-to-phase voltages are greater than the voltage setting of the voltage blocking element of the frequency protection if the stage 1 over-frequency protection is enabled and ready for operating.

37. The frequency is greater than the setting of the stage 2 over-frequency protection and all the phase-to-phase voltages are greater than the voltage setting of the voltage blocking element of the frequency protection if the stage 2 over-frequency protection is enabled and ready for operating.

38. The rate-of-change of frequency is greater than the setting of the stage 1 frequency rate-of-change protection if the stage 1 frequency rate-of-change protection is enabled.




42. If anyone the binary inputs of the mechanical protections is energized if the corresponding mechanical protection is enabled.

The FD (Fault Detector) element will reset to normal operation status 10s later if the auto-recloser is enabled or 500ms later if the auto-recloser is disabled, after the last one of the above items is reverted.

3.3 Overcurrent Protection

3.3.1 Definite Time Overcurrent Protection

The overcurrent protection in this relay provides a four-stage phase overcurrent protection with independent definite time characteristics. Each stage can be enabled or disabled independently by the logic settings respectively. All overcurrent element, directional element, voltage control element and harmonic blocking element settings apply to all three phases but are independent for each of the four stages. Configuring the relevant settings can enable or disable the corresponding protection.

The first three stages of overcurrent protection only have definite time characteristics, and they have the same protective functional logic. The stage 4 overcurrent protection can be set as either definite time (DT) or inverse definite minimum time (IDMT). The demonstration characteristic figure of the DT overcurrent protection and IDMT overcurrent protection is shown as below.

3 Operation Theory


tDelay

50/51P2.I_Set Inom50/51P1.I_Set

50/51P2.t_Op

50/51P1.t_Op

tDelay

Inom

DT OC IDMT OC

Figure 3.3-1 Demonstration characteristic of the overcurrent protection

The logic diagram of the stage 1 overcurrent protection is shown in Figure 3.3-2. The overcurrent block is a level detector that detects whether the current magnitude is above the threshold.

The stage 2 overcurrent protection and the stage 3 overcurrent protection have the same logic diagrams with the stage 1 overcurrent protection, but the operation thresholds are [50/51P2.I_Set] and [50/51P3.I_Set] respectively.

The logic diagram of the stage 4 overcurrent protection with definite time characteristic is shown in Figure 3.3-3, if the setting [50/51P4.Opt_Curve] is set as 0.

Figure 3.3-2 Logic diagram of the stage 1 overcurrent protection

Where:

[50/51P1.I_Set] is the current setting of the stage 1 overcurrent protection;

tOC1 is the setting [50/51P1.t_Op], the time setting of the stage 1 overcurrent protection;

[50/51P1.En] is the logic setting of the stage 1 overcurrent protection;

[50/51P1.En1] is the binary signal for enabling the stage 1 overcurrent protection;

[50/51P1.Blk] is the binary signal for blocking the stage 1 overcurrent protection;

50/51P1.VCE_x (x: A, B, C) denotes the state of the voltage control element of the stage 1 overcurrent protection, see Section 3.3.3 for more details about the voltage control element;

3 Operation Theory


50/51P1.Dir_x (x: A, B, C) denotes the state of the directional element of the stage 1 overcurrent protection, see Section 3.3.4 for more details about the directional element;

50/51P1.HmBlk_x (x: A, B, C) denotes the harmonic blocking element of the stage 1 overcurrent protection, see Section 3.3.5 for more details about the harmonic blocking element.

3.3.2 Inverse Definite Minimum Time Overcurrent Protection

The stage 4 overcurrent protection also can be used as inverse definite minimum time (IDMT) overcurrent protection if the setting [50/51P4.Opt_Curve] is not set as 0.

Various methods are available to achieve correct relay coordination on a system; by means of time alone, current alone or a combination of both time and current. Grading by means of current is only possible where there is an appreciable difference in fault level between the two relay locations. Grading by time is used by some utilities but can often lead to excessive fault clearance times at or near source substations where the fault level is highest. For these reasons the most commonly applied characteristic in coordinating overcurrent relays is the IDMT type.

The inverse time delayed characteristics comply with the following formula (based on IEC60255-3 and IEEE Std C37.112-1996 standard).

p

p

TCIIkt

+= 1)/(

Where:

k = Constant, the setting [50/51P4.K].

= Constant, the setting [50/51P4.Alpha].

C = Constant, the setting [50/51P4.C].

t = Operation time .

I = Measured phase current.

Ip is the current threshold setting; the current setting of the stage 4 overcurrent [50/51P4.I_Set] is used as the Ip in this relay. If the stage 4 overcurrent protection is used as IDMT overcurrent protection, the range of the setting [50/51P4.I_Set] is 0.05In ~ 4In.

Tp is the time multiplier setting; the multiplier setting of the IDMT overcurrent protection [50/51P4.TMS] is used as Tp in this relay. If the stage 4 overcurrent protection is used as IDMT overcurrent protection, the range of the setting [50/51P4.TMS] is 0.05 ~ 100.00.

Some recommended types of IDMT characteristic curves are applied in this relay. It is also can be programmed according to the demand of the special practical application through the PCS-PC configuration tool auxiliary software.

The setting [50/51P4.Opt_Curve] can be used to select the expected curve.

3 Operation Theory


Setting Value Standard Time Characteristic k C

0 Definite Time

1 IEC Standard Inverse 0.14 0.02 0.00

2 IEC Very Inverse 13.5 1.00 0.00

3 IEC Extremely Inverse 80.0 2.00 0.00

4 IEC Short Time Inverse 0.05 0.04 0.00

5 IEC Long Time Inverse 120.0 1.00 0.00

6 IEEE (ANSI) Extremely Inverse 28.20 2.00 0.1217

7 IEEE (ANSI) Very Inverse 19.61 2.00 0.491

8 IEEE (ANSI) Inverse 0.0086 0.02 0.0185

9 IEEE (ANSI) Moderately Inverse 0.0515 0.02 0.114

10 IEEE (ANSI) Long Time Extremely Inverse 64.07 2.00 0.25

11 IEEE (ANSI) Long Time Very Inverse 28.55 2.00 0.712

12 IEEE (ANSI) Long Time Inverse 0.086 0.02 0.185

13 User Programmable

If the setting [50/51P4.Opt_Curve] is set as 1 to 12, these settings [50/51P4.K], [50/51P4.Alpha] and [50/51P4.C] do not need to be set, and this relay will use these values as listed in above table.

The logic diagram of the stage 4 overcurrent protection is shown in Figure 3.3-3. The overcurrent block is a level detector that detects whether the current magnitude is above the threshold.

Figure 3.3-3 Logic diagram of the stage 4 overcurrent protection

Where:

[50/51P4.I_Set] is the current setting of the stage 4 overcurrent protection;

tOC4 is the setting [50/51P4.t_Op], the time setting of the stage 4 overcurrent protection;

[50/51P4.En] is the logic setting of the stage 4 overcurrent protection;

[50/51P4.En1] is the binary signal for enabling the stage 4 overcurrent protection;

3 Operation Theory


[50/51P4.Blk] is the binary signal for blocking the stage 4 overcurrent protection;

[50/51P4.Opt_Curve] is the setting for selecting the inverse time characteristic curve;

50/51P4.VCE_x (x: A, B, C) denotes the state of the voltage control element of the stage 4 overcurrent protection, see Section 3.3.3 for more details about the voltage control element;

50/51P4.Dir_x (x: A, B, C) denotes the state of the directional element of the stage 4 overcurrent protection, see Section 3.3.4 for more details about the directional element;

50/51P4.HmBlk_x (x: A, B, C) denotes the harmonic blocking element of the stage 4 overcurrent protection, see Section 3.3.5 for more details about the harmonic blocking element.

3.3.3 Voltage Control Element for Overcurrent Protection

If the current detected by a local relay for a remote fault condition is below its overcurrent setting, a voltage controlled overcurrent (VCO) element may be used to increase the relay sensitivity to such faults. In this case, a reduction in system voltage will occur; this may then be used to reduce the pick up level of the overcurrent protection. The VCO function can be selectively enabled on the four stages of the main overcurrent element, which was described in Section 3.3.1. When the VCO is enabled, the overcurrent setting can be modified just to be in excess of the maximum value of the load current.

Overcurrent Element Voltage for Controlling

Ia> Uab< or Uca< or U2>

Ib> Ubc< or Uab< or U2>

Ic> Uca< or Ubc< or U2>

Note that the voltage dependent overcurrent relays are more often applied in practical protection applications in order to give adequate overcurrent relay sensitivity for close up fault conditions. The fault characteristic of this protection must then coordinate with any of the downstream overcurrent relays that are responsive to the current decrement condition. It therefore follows that if this relay is to be applied on an outgoing feeder from a generator station, the use of voltage controlled overcurrent protection in the feeder relay may allow better coordination with the VCO relay on the generator.

For the operation accuracy of the VCO protection, it is necessary to take the status of the voltage transformer into account. If the voltage transformer has a fault, the numerical relay will issue an [VTS.Alm] signal and block all the elements that relate to the voltage measurement.

The logic diagram of the voltage control overcurrent protection is shown in Figure 3.3-2. Each stage of the overcurrent protection can be set with voltage control by its relevant independent setting respectively. The detailed logic diagram for the voltage control element of phase A for the stage 1 overcurrent protection is shown as below. The logic diagrams for voltage control elements of phase B and phase C can be gotten on the analogy of this.

3 Operation Theory


Figure 3.3-4 Logic diagram of the OC1 phase A voltage control element

Where:

[50/51P.Upp_VCE] is the voltage setting of the undervoltage control element;

[50/51P.U2_VCE] is the voltage setting of the negative sequence overvoltage control element;

[VTS.En] is the logic setting of the protection voltage transformer supervision function;

[50/51P1.En_VCE] is the logic setting of the voltage control element for the OC1 protection;

[50/51P.En_VTS_Blk] is the logic setting of the function which can block all the OC protective elements that relate to the voltage measurement when the voltage transformer is failed;

[VTS.Alm] is the alarm signal of the protection voltage transformer supervision.

3.3.4 Directional Element for Overcurrent Protection

The phase fault elements of this relay are internally polarized by the quadrature phase-to-phase voltages, as shown in the table below:

Phase of Protection Operate Current Polarizing Voltage

A Phase Ia Ubc

B Phase Ib Uca

C Phase Ic Uab

Under system fault conditions, the fault current vector will lag its nominal phase voltage by an angle dependent upon the system X/R ratio. It is therefore a requirement that the relay operates with maximum sensitivity for currents lying in this region. This is achieved by means of the relay characteristic angle (RCA) setting; this defines the angle by which the current applied to the relay must be displaced from the voltage applied to the relay to obtain maximum relay sensitivity.

For a close up three-phase fault, all three voltages will collapse to zero and no healthy phase voltages will be present. For this reason, the relay includes a synchronous polarization feature that stores the pre-fault positive sequence voltage information and continues to apply it to the directional overcurrent elements for a time period of 25 fundamental wave cycles, after which, it will keep the result of the directional element, this ensures that either the instantaneous or the time delayed directional overcurrent elements will be allowed to operate, even with a three-phase voltage collapse.

The relay characteristic angle (RCA) is configurable through the setting [50/51P.RCA]. A directional check is performed based on the following criteria:

3 Operation Theory


z Directional forward -90 < (angle(U) - angle(I) - RCA) < 90

z Directional reverse -90 > (angle(U) - angle(I) - RCA) > 90

Forward

Reverse

O U

IRCA

Figure 3.3-5 Operation characteristic of the OC directional element

The setting [50/51Px.Opt_Dir] (x: 1~4) is used to select the directional mode for the stage x (x: 1~4) overcurrent protection respectively.

Setting Value 0 1 2

Directional Mode Non-directional Forward directional Reverse directional

Any of the four overcurrent stages may be configured to be directional. When the element is selected as directional, a VTS block option is available. When the relevant setting is set as 1, operation of the voltage transformer supervision (VTS) will block the stage if the relevant directional element is in service. When the relevant setting is set as 0, the stage will revert to non-directional upon operation of the VTS.

The logic diagram of the phase directional overcurrent protection is shown in Figure 3.3-2. Each stage of the overcurrent protection can be set with directional element control by its relevant independent setting respectively. The detailed logic diagram for the phase A directional element for the stage 1 overcurrent protection is shown as below. The logic diagrams of voltage control elements of phase B and phase C can be gotten on the analogy of this.

[VTS.En][50/51P.En_VTS_Blk]

[VTS.Alm]

Ubc(present measure)Ia (present measure)

[50/51P1.Opt_Dir] 0Ubc(in memory)

Phase ADirectionCheck

&50/51P1.Dir_A

Figure 3.3-6 Logic diagram of the OC1 phase A directional element

Where:

[50/51P1.Opt_Dir] is the setting which is used to select the directional mode (non-directional, forward, reverse) of the directional element for the stage 1 overcurrent protection;

3 Operation Theory


[VTS.En] is the logic setting of the protection voltage transformer supervision function;

[50/51P.En_VTS_Blk] is the logic setting of the function which can block all the OC protective elements that relate to the voltage measurement when the voltage transformer is failed;

[VTS.Alm] is the alarm signal of the protection voltage transformer supervision.

3.3.5 Harmonic Blocking Element for Overcurrent Protection

To prevent maloperation of the overcurrent protection when the transformer is energized without any load, this relay provides a 2nd harmonic blocking function for resolving such a problem.

The percent threshold of the 2nd harmonic blocking element to the fundamental wave can be set through the setting [50/51P.K_Hm2].

The harmonic blocking mode can be selected through the setting [50/51P.Opt_Hm_Blk].

Harmonic Blocking Criterion Setting Value

Phase A Phase B Phase C

1 Phase blocking Ia2/ Ia1 > Ib2/ Ib1 > Ic2/ Ic1 >

2 Cross blocking (Ia2/ Ia1 >) or (Ib2/ Ib1 >) or (Ic2/ Ic1 >)

3 Maximum blocking Max(Ia2, Ib2, Ic2)/ Ia1 > Max(Ia2, Ib2, Ic2)/ Ib1 > Max(Ia2, Ib2, Ic2)/ Ic1 >

When the fundamental current is greater than the setting [50/51P.I_Rls_HmBlk], the harmonic blocking element of the corresponding phase is released.

The following figure shows the logic diagram of the harmonic blocking element of phase A for the stage 1 overcurrent protection. The logic diagrams of the harmonic blocking elements of phase B and phase C can be gotten on the analogy of this.

Figure 3.3-7 Logic diagram of the OC1 phase A harmonic blocking element

Where:

[50/51P1.En_HarmBlk] is the logic setting of the harmonic blocking element of the stage 1 overcurrent protection;

[50/51P.K_Hm2] is the percent setting of the harmonic blocking element for OC protection;

[50/51P.I_Rls_HmBlk] is the current setting for releasing the harmonic blocking element;

[50/51P.Opt_Hm_Blk] is the setting for selecting the harmonic blocking criterion;

3 Operation Theory


Ix1 (x: a, b or c) is the fundamental current