38418962 Fundamentals of Teleprotection Systems

7/22/2019 38418962 Fundamentals of Teleprotection Systems

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ABB AutomationUtility Communication Systems

CHPAU NKT F 1

Fundamentalso f

Teleprotect ionSystems

27.06.2001


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CHPAU NKT F 2

Teleprotection - Contents

Introduction / Protection Systems Protection Schemes / Applications

Parameters in Teleprotection

Modulation Methods

Transmission Principles

Transmission Equipment


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CHPAU NKT F 3

Teleprotection - Introduction

What is it ?-> Tele-Communication + Protect ion- Signalling

Where is it used ?-> Mainly at the higher and highest voltage levels

Why is it used ?-> Clearance of faults within the shortest possible time


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CHPAU NKT F 4

TPS Standards and Publications

IEC standards:

IEC 60834-1 Teleprotection equipment of power systems - Performance and testing

Part 1: Narrow-band systems (First edition, 1988)

Part 1: Command systems (Second edition, 1999)

IEC 60834-2 Performance and testing of teleprotection equipment of power systems

Part 2: Analogue comparison systems (First Edition 1993)

CIGRE publications:

"Teleprotection Guide", Study Committees 34 + 35, Joint Working Group on

Teleprotection, 1969;

Revised Version "Protection Systems Using Telecommunication", 1985Revised Version "Protection Using Telecommunications", 2000 (in preparation)


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CHPAU NKT F 5

Protection System Architecture

Substation A

HV-line

Substation B

PhysicalLink

Telecommunication

System

Tele-

protection

Equipment

Tele-

protection

Equipment

Teleprotection System

ProtectionRelay

ProtectionRelay

Protection System


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CHPAU NKT F 6

Protection Signal Transmission

Type of Information: Continuous signals

Magnitude and/or phase of power frequency currents

Command type signals (on/off)

Trip / do not trip


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CHPAU NKT F 7

Protection Systems

Local Information Information from all points

Signal-transmission

not required

Signal-transmission

required

Not selective Selective

with time delay No time delay

conditionally selective

Protection system based on:


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CHPAU NKT F 8

Signal Transmission for Line Protection

Amplitude

and/or

Phase

command =

Blocking

of breaker tripping

command =

Permission of / direct

breaker tripping

Quantitative (analogue)

Information

Binary (yes / no)

Information

commands

SIGNAL TRANSMISSION

IS

ESSENTIAL

SIGNAL TRANSMISSION

IS

SUPPLEMENTARY


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CHPAU NKT F 9

Distance Protection

B

A, B, C Stations

RA,RB, RC Protection RelayTA1, TA2, TA3 Operating Times, Relay A

TB1, TB2, TB3 Operating Times, Relay B

Typical stepped distance/time characteristics

RA RB RC

A C

Distance

OperatingTime

ZONE 1

ZONE 2

ZONE 3

TA2

TA1

TB2

TB1

TA3


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CHPAU NKT F 10

Distance Line Protection

NSD

RBC

NSD

RCB

LBC

BC1

CB1

L

FB C

B, C Substations

LBC Protected line section

RBC,RCB Protection relayBC1, CB1 Zone 1 reach, 85% of line section

F Line fault

L Communication channel(PLC, Microwave, Cable)

Permissive Underreach Transferred Tripping (PUTT)


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CHPAU NKT F 11


NSD

RBC

NSD

RCB

LBC

BC1

CB1

L

FB C

B, C Substations



F Line fault


Permissive Overreach Transferred Tripping (POTT)


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CHPAU NKT F 12


NSD

RBC

NSD

RCB

LBC

BC1

CB1

L

FB C

B, C Substations



F Line fault


Direct Transfer Tripping (DTT)


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CHPAU NKT F 13

Transformer Protection

Example for direct tripping

L

B

C

P Pilot cable

L HV Transmission Line

or -Cable

NSD 70C

NSD 70C

P

Di Li P i


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CHPAU NKT F 14


NSD

BCe

NSD

RCB

LBC

BCi

CBi

L

FB C

B, C Substations


RBC,RCB Protection relayBCi, CBi Zone 1 reach, 130% in direction of the protected line section

BCe, CBe Range of protection relay in direction of busbars

F Line fault

L Communication channel

(PLC, Microwave, Cable)

Blocking

RBC

CBe


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CHPAU NKT F 15

Teleprotection command transmission

Transmission

time

Commandinput (local)

Command

output (remote)

Genuine

Command

Disturbance,

Impairments

Missing

Command

Dependability

Unwanted

Command

Security


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CHPAU NKT F 16

Telecommunication Channel Impairments

Impairments resulting from interference and noise

Isolater / breaker operation 50/60 Hz harmonics (pilot cables) Corona noise (PLC channels) Fading (microwave channels) Jitter (digital networks)

Temporary loss of synchronism (digital networks) Signal interruptions etc.

Disturbed signals may cause protection equipment tomaloperate

f C f


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CHPAU NKT F 17

Bandwidth orData Rate

Optimization / Exchange according to application

Transmission

Time

Performance Criteria for Teleprotection

Dependability

(Probability

of missing

command)

Security

(Probability of

unwanted command)

Li P t ti


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CHPAU NKT F 18

Line Protection

Designation Short description Typical distance Requirements for trans-

relay setting (%) mission channel as regardsStep 1

Speed Security Dependability

1 Permissive underreach Starting of distance relay 85 M-H M-H Htransferred tripping permits tripping

2 Permissive overreach Directional comparison 130 H M Htransferred tripping (signal permits tripping)

3 Permissive underreach Carrier acceleration 85 (130*) H L-M H

transferred acceleration by extension of step (*)

4 Blocking (direct overreach, Blocking signals are transmitted 130 S L Htransferred blocking) over healthy lines

5 Blocking Signal inhibits step extension (*) 85 (130*) H-S L M

6 Unblocking Loss of guard signal permits 130 H M Mtripping for limited time only

7 Direct underreach Status of relay at receiving end 85 M-H S H

transferred tripping not taken into account

L = Low M = Medium H = High S = Very severe requirements

Possible Signal Connections Between two Distance Relays

T t l F lt Cl Ti


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CHPAU NKT F 19

Total Fault-Clearance-Time

Time delay between fault occurrence and line tripping

The fault-clearance time results from: Relay-time (fault detection) TREL Command transmission time TAC Switching delay of line breaker TBR

Typical values:TTotal = TREL + TAC + TBR75 ms = 20 ms + 15 ms + 40 ms

Target: TTotal = less than 100 ms, Worst Case= 4.5 to 5 cycles max. (50 Hz)

T i l i t f diff t li ti


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CHPAU NKT F 20

Typical requirements for different applications

Line protection with permissive transfer tripping: Transmission time T0 = 10 ... 20 ms

Dependability Plost command 10-2 ... 10-3 Security Pfalse command 10-3 ... 10-4

Line protection with blocking system: Transmission time T0 = 6 ... 15 ms Dependability P

lost command10-3

Security Pfalse command 10-2

Direct transfer tripping (e.g. transformer protection): Transmission time T0 = 20 ... 50 ms Dependability Plost command 10-3 ... 10-4

Security Pfalse command

10-5

... 10-6

C d S t T i l Fi


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CHPAU NKT F 21

Command Systems, Typical Figures

Blocking short transmission time Tac < 15 ms < 10 ms

moderate security Puc < 1E-2 < 1E-6 high dependability Pmc < 1E-3 < 1E-3

Permissive tripping moderate transmission time Tac < 20 ms < 10 ms

moderate to high security Puc < 1E-3 ....1E-4 < 1E-6 moderate to high dependability Pmc < 1E-2 ....1E-3 < 1E-3

Direct tripping moderate transmission time Tac < 40 ms < 10 ms very high security Puc < 1E-5 .... 1E-6 < 1E-9 very high dependability Pmc < 1E-3 < 1E-3

Analog systems Digital systems

Teleprotection Equipment Command Systems


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CHPAU NKT F 22

Teleprotection Equipment Command Systems

NSD 50 / NSD550 Plug in unit for multi-purpose Power Line Carrier type ETL

HSD 50 Dedicated protection Power Line Carrier

NSD 70, NSD 70C for analog bearers

cables speech channels of analog and digital links power line carrier channels

NSD 70D for digital bearers

digital multiplexers

digital radio, fibre optic links with plug-in fibre optic line unit for dedicated fibres

TEBIT: Teleprotection & binary interface


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CHPAU NKT F 23

TEBIT: Teleprotection & binary interface

TEBIT as teleprotection interface:

- 4 commands, full-duplex

- addressable

TEBIT as binary interface:

- max. 12 binary inputs

- max. 12 binary outputs

as Mini-RTU

Digital Networks


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CHPAU NKT F 24

Digital Networks

High capacity = large number of channels

Basic channel capacity = 64 kbit/s

PDH (Plesiochronous digital hierarchy) Multiplexing into 2 Mbit/s ( 30 channels)

8 Mbit/s (120 channels)etc. ( ..... channels)

SDH (Synchronous Digital Hierarchy) Multiplexing of n * 64 kbit/s or n * 2 Mbit/s into 155 Mbit/s etc.

Cross-connect functionality

Radio or optical fibre links

Digital Cross Connect Networks


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CHPAU NKT F 25

Digital Cross-Connect Networks

Network -

Management

Network management

act iv i t ies may have a

detr imental impact on a

protect ion system, unless

adequate precaut ion s aretaken

Digital Cross-ConnectProtection terminal

Digital network

Digital Cross Connect Precautions


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CHPAU NKT F 26

Digital Cross-Connect Precautions

Restricted authorisation for re-routing

Inhibit auto-rerouting (possibility of excessive delay)

Use (tele)protection equipment with addressing facility

Use dedicated channels for protection signalling whichare non-cross-connectable

Use dedicated links for protection signallingIncreasing

Security

800 kV redundant Line Protection ( ith NSD 50 d NSD 70)


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CHPAU NKT F 27

POTT1

PUTT Permissive underreach

tripping

NSD 70 indirect

POTT 1 Permissive overreach

tripping

NSD 70 indirect


tripping

NSD 50 indirect

RM 91 Directional comp. prot.

NSD 70 indirect

RE 93 Earth fault protection

NSD 50 indirect

BFP Breaker fail protection

NSD 50 direct

GSD Generator protection

NSD 50 direct

AB

C

D

A

B

NSD50

ETL81

PLCI

NSD70

Coupling

HV transmission line

A

B

C

D

B

NSD50

ETL81

PLCII

NSD70

PUTTPOTT1

POTT2

RM91

RE93

LINEPROT

I

POTT2

RM91

RE93

LINE

PROTII

GSDfrom

generator

Breaker Transducers

BFP

A

PUTT

800 kV redundant Line Protection (with NSD 50 and NSD 70)

800 kV redundant Line Protection


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CHPAU NKT F 28

POTT1

PUTT Permissive underreach

tripping

NSD 70 indirect


tripping

NSD 70 indirect


tripping

NSD 550 indirect

RM 91 Directional comp. prot.NSD 70 indirect

RE 93 Earth fault protection

NSD 550 indirect

BFP Breaker fail protection

NSD 550 direct

GSD Generator protection

NSD 550 direct

A

BC

D

A

B

NSD550ETL580

PLC

NSD70

Coupling

HV transmission line

A

B

C

D FOX515

PUTT

POTT1POTT2

RM91

RE93

LINEPROT

I

POTT2

RM91RE93

LINEPROT

II

GSDfrom

generator

Breaker Transducers

BFP

PUTT

800 kV redundant Line Protection

TEBIT

D

A

BC

D

TEBIT

Optical fiber

Documents

38418962 Fundamentals of Teleprotection Systems