PO'WER SYSTEM PROTECTION Volume 1: Principles and components Edited by The Electricity Training Association Volume 2: Systems and methods Edited by The Electricity Training Association Volume 3: Application Edited by The Electricity Training Association Volume 4: Digital protection and signalling Edited by The Electricity Training Association The Institution of Electrical Engineers CuuDuongThanCong.com https://fb.com/tailieudientucntt Published by: The Institution of Electrical Engineers, London, United Kingdom First published 1969 by Macdonald & Co. (Publishers) Limited © 1969; The Electricity Council Revised edition 1981 by Peter Peregrinus Limited on behalf of the Institution of Electrical Engineers @ 1981: The Electricity Council Reprinted with minor corrections 1986 Reprinted 1990 Second revised edition 1995 by the Institution of Electrical Engineers ¢ 1998: Electricity Association Services Limited Reprinted 1997 This publication is copyright under the Berne Convention and the Universal Copyright Convention. All rights reserved. Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act, 1988, this publication may be reproduced, stored or transmitted, in any forms or by any means, only with the prior permission in writing of the copyright holder and publishers, or in the case of reprographic reproduction in accordance with the terms of licences issued by the Copyright Licensing Agency, Inquiries concerning reproduction outside those terms should be sent to the publishers at the undermentioned address: The Institution of Electrical Engineers, Michael Faraday House, Six Hills Way, Stevenage, Harts.
SG1 2AY, United Kingdom While the editor and the publishers believe that the information and guidance given in this work is correct, all parties must rely upon their own skill and judgment when making use of it. Neither the editor nor the publishers assume any liability to anyone for any loss or damage caused by any error or omission in the work, whether such error or omission is the result of negligence or any other cause. Any and all such liability is disclaimed. The moral right of the authors to be identified as authors of this work has been asserted by them in accordance with the Copyright, Designs and Patents Act 1988.
British Library Cataloguing in Publication Data A CIP catalogue record for this book is available from the British Library ISBN 0 85296 834 5 Printed in the United Kingdom at the UniversityPress, Cambridge CuuDuongThanCong.com https://fb.com/tailieudientucntt Published by: The Institution of Electrical Engineers, London, United Kingdom First published 1969 by Macdonald & Co. (Publishers) Limited © 1969: The Electricity Council Revised edition 1981 by Peter Peregrinus Limited on behalf of the Institution of Electrical Engineers © 1981: The Electricity Council Reprinted with minor corrections 1986 Reprinted 1990 Second revised edition 1995 by the Institution of Electrical Engineers © 1995: Electricity Association Services Limited This publication is copyright under the Berne Convention and the Universal Copyright Convention. All rights reserved. Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act, 1988, this publication may be reproduced, stored or transmitted, in any forms or by any means, only with the prior permission in writing of the copyright holder and publishers, or in the case of reprographic reproduction in accordance with the terms of licences issued by the Copyright Licensing Agency.
Inquiries concerning reproduction outside those terms should be sent to the publishers at the undermentioned address: The Institution of Electrical Engineers, Michael Faraday House, Six Hills Way, Stevenage, Herts. SG1 2AY, United Kingdom While the editor and the publishers believe that the information and guidance given in this work is correct, all parties must rely upon their own skill and judgment when making use of it. Neither the editor nor the publishers assume any liability to anyone for any loss or damage caused by any error or omission in the work, whether such error or omission is the result of negligence or any other cause. Any and all such liability is disclaimed.
The moral right of the authors to be identified as authors of this work has been asserted by them in accordance with the Copyright, Designs and Patents Act 1988. British Library Cataloguing in Publication Data A CIP catalogue record for this book is available from the British Library ISBN 0 85296 836 1 Printed in United Kingdom at the University Press, Cambridge CuuDuongThanCong.com https://fb.com/tailieudientucntt Published by: The Institution of Electrical Engineers, London, United Kingdom First published 1969 by Macdonald & Co. (Publishers) Limited © 1969: The Electricity Council Revised edition 1981 by Peter Peregrinus Limited on behalf of the Institution of Electrical Engineers © 1981: The Electricity Council Reprinted with minor corrections 1986 Reprinted 1990 Second revised edition 1995 by the Institution of Electrical Engineers © 1995: Electricity Association Services Limited Reprinted 1997 This publication is copyright under the Berne Convention and the Universal Copyright Convention. All rights reserved.
Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act, 1988, this publication may be reproduced, stored or transmitted, in any forms or by any means, only with the prior permission in writing of the copyright holder and publishers, or in the case of reprographic reproduction in accordance with the terms of licences issued by the Copyright Licensing Agency. Inquiries concerning reproduction outside those terms should be sent to the publishers at the undermentioned address: The Institution of Electrical Engineers, Michael Faraday House, Six Hills Way, Stevenage, Herts. SG1 2AY, United Kingdom While the editor and the publishers believe that the information and guidance given in this work is correct, all parties must rely upon their own skill and judgment when making use of it. Neither the editor nor the publishers assume any liability to anyone for any loss or damage caused by any error or omission in the work, whether such error or omission is the result of negligence or any other cause.
Any and all such liability is disclaimed. The moral right of the authors to be identified as authors of this work has been asserted by them in accordance with the Copyright, Designs and Patents Act 1988. Bdtish Library Cataloguing in Publication Data A CIP catalogue record for this book is available from the British Library ISBN 0 85296 837 X Printed in the United Kingdom at the University Press, Cambridge CuuDuongThanCong.com https://fb.com/tailieudientucntt Published by: The Institution of Electrical Engineers, London, United Kingdom © 1995: Electricity Association Services Limited Reprinted 1997, 2005 This publication is copyright under the Berne Convention and the Universal Copyright Convention. All rights reserved.
Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act, 1988, this publication may be reproduced, stored or transmitted, in any forms or by any means, only with the prior permission in writing of the copyright holder and publishers, or in the case of reprographic reproduction in accordance with the terms of licences issued by the Copyright Licensing Agency. Inquiries concerning reproduction outside those terms should be sent to the publishers at the undermentioned address: The Institution of Electrical Engineers, Michael Faraday House, Six Hills Way, Stevenage, Herts. SG1 2AY, United Kingdom While the editor and the publishers believe that the information and guidance given in this work is correct, all parties must rely upon their own skill and judgment when making use of it. Neither the editor nor the publishers assume any liability to anyone for any loss or damage caused by any error or omission in the work, whether such error or omission is the result of negligence or any other cause.
Any and all such liability is disclaimed. The moral right of the authors to be identified as authors of this work has been asserted by them in accordance with the Copyright, Designs and Patents Act 1988. British Library Cataloguing in Publication Data A CIP catalogue record for this book is available from the British Library ISBN 0 85296 838 8 Printed In Great BrlUan at the University Press, Cambridge CuuDuongThanCong.com https://fb.com/tailieudientucntt Contents Foreword xiv Chapter authors xvi Editorial panel xvii ~°° Protection symbols used in circuit diagrams XVIII 1 Role of protection M.2 Role of protection in a power station 1.2 System and substation layout 3 1.3 Current transformer location 7 1.1 Neutral-earthing methods 7 1.2 Special cases of resistance earthing I0 1.1 Faults and other abnormalities I0 1.2 Nature and causes of faults II 1.5 Basic terms used in protection 15 1.6 Necessity for back-up protection 16 1.3 Transmission systems 19 CuuDuongThanCong.com https://fb.com/tailieudientucntt Conten~ 1,8 Bibliography 20 2 Protection principles and components H.Rushton 21 2,1 Fundamental principles 21 2.1 Methods of discrimination 21 2.2 Derivation of relaying quantities 30 2.3 Combined overcurrent and earth fault relays 33 2.4 Derivation of a representative single-phase quantity from a three-phase system 33 2,2 Components of protection 37 2,2.3 Voltage transforming devices 38 2.8 Tripping and other auxiliary supplies 42 2.9 Fuses, small wiring, terminals and test links 44 2,2.10 Pilot circuits 47 2,3 Consideration of the protection problem 48 2,4 Bibliography 52 3 Fault calculations J.1 Purpose of fault calculation 53 3.2 Types of fault 54 3.3 Factors affecting fault severity 58 3.4 Methods of fault calculation 59 3,2 Basic principles of network analysis 60 3.1 Fundamental network laws 60 3.2 Mesh-current analysis 65 3.3 Nodal-voltage analysis 66 3,2.4 Application of mesh-current and nodal-voltage analysis 68 3,2.5 Network theorems and reduction formulas 69 3,3 Calculations of balanced fault conditions 77 3,3.1 Single-phase representation 77 3.2 Use of a common voltage base 81 3.3 Representation of nominal-ratio transformer circuits 87 3.4 Representation of off-nominal-ratio transformer circuits 94 3.5 Transformer phase-shifts 95 3.6 Representation of synchronous machines 98 3,3.7 Use of per-unit and per-cent values 104 3,3.8 Fault-calculation procedure 108 3.com https://fb.com/tailieudientucntt Contenta 3.4 Calculation of unbalanced fault conditions 126 3.2 Phase-sequence networks and impedances 129 3.3 Phase-sequence equivalent circuits 134 3A.4 Analysis of short-circuit conditions 153 3.5 Effect of fault impedance 168 3.6 Analysis of open-circuit conditions 173 3.7 Transformer phase-shifts 178 3.8 Fauit-calculation procedure 182 3.5 Calculation of simuRaneons fault conditions 202 3.2 Cross-country earth-fauR 204 3.3 Sequence network interconnections 206 3.6 Practical network analysis 217 3.2 Digital-computer analysis 22! 3.2 Generator-winding faults 223 3.3 Transformer-winding faults 228 3.1 Representation of off-nominal-ratio transformers 230 3.2 Effects of overhead-fine asymmetry 242 3.9 Bibliography 245 4 Protective transformers N.Ashton and EJ.2 Steady-state theory of current transformers 248 4.1 Equivalent circuit, vector diagram, errors 248 4.2 Influence of the core, magnetic materials, and magnetisation curves 250 4.3 Single-turn primary current transformers 253 4.5 Balancing windings and eddy-current shielding 25~ 4.6 Open-circuit secondary voltage 258 CuuDuongThanCong.com https://fb.com/tailieudientucntt Contents 4.7 Secondary currents, borders and connecting lead resistance 258 4.3 Current transformers for protection 259 4.1 Saturation of the core and ratio on overcurrents.2 Trip-coil operation 260 4,3.3 Overcurrent-relay operation 260 4,3.4 Earth-fault relays with inverse-time characteristics 261 4.5 Relay settings and primary operating currents 261 4.6 Current transformers for balanced differential protective schemes 262 4.7 Simple transient-state theory 264 4.4 Construction of current transformers 267 4.2 Forms of cores 269 4.3 Windings and insulation 270 4.4 High-voltage current transformers 272 4.S Testing of current transformers 274 4.2 Turns ratio tests 276 4.4 Current transformers for balanced differential protective schemes 277 4.6 Voltage-transformer theory 278 4.1 Electromagnetic-type voltage transformers 278 4.2 Capacitor-type voltage transformers 279 4.3 Burdens and lead resistances 283 4.7 Voltage transformers for protection 285 4.1 Electromagnetic type, categories, residual voltages 285 4.2 Capacitor type 287 4,8 Construction of voltage transformers 293 4.4 Capacitor divider voltage sensor 302 4,8.5 Voltage transformers for SF6 metalclad switchgear 303 4.9 Fusing and protection of voltage transformers 304 4,10 Testing of voltage transformers 304 4,10.4 Polarity 305 4,11 Bibliography 306 CuuDuongThanCong.com https://fb.com/tailieudientucntt Contents 5 Fuses H. Turner and C Turner 307 5.1 Definition of a fuse 307 5.2 Definition of a fuselink 307 5.3 Categories of fuse 307 5.1 Powder-filled cartridge fuse 311 5.1 High-voltage powder-filled fuses 313 5.3 Semi-enclosed fuse 315 5.