High High High voltage voltage voltage circuit circuit circuit breakers. breakers. breakers. High voltage circuit breakers. High voltage circuit breakers. High voltage circuit breakers. Mirsad Kapetanovic

Mirsad Kapetanovic

Mirsad Kapetanovic

www.kema.com www.kema.com www.kema.com

Sarajevo, 2011

Mirsad Mirsad Mirsad Kapetanovic Kapetanovic Kapetanovic

Price: € 150.00 (BAM 296.35) Publisher:

ETF − Faculty of Electrotechnical Engineering, Sarajevo

Author:

Prof. dr. Mirsad Kapetanović

Reviewers:

Prof. dr. Kemo Sokolija Prof. dr. Mensur Hajro Prof. dr. René Peter Paul Smeets

Chief Editor:

Prof. dr. René Peter Paul Smeets

Translation:

Maja Kapetanović, M.Sc

Proofreading:

Scott Wilson

Cover design:

JTP Creative Marketing of KEMA – JTP Branding & Marketing

DTP:

Mahir Sokolija

Copyright © 2011 Author. Telephone: E-mail (for orders):

+ 387 61 194 987 [email protected]

All rights reserved. This work is protected under international copyright laws, treaties and conventions. No part of this work may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying and recording, or by any information storage or retrieval system, without the express written permission of the author. Positions and opinions advanced in this book are those of the author and not necessarily those of KEMA. CIP – Katalogizacija u publikaciji Nacionalna i univerzitetska biblioteka Bosne i Hercegovine, Sarajevo 621.316.542.027.3(075.8) KAPETANOVIĆ, Mirsad High voltage circuit breakers / Mirsad Kapetanović ; [translation Maja Kapetanović]. – Sarajevo : Faculty of Electrotechnical Engineering, 2011. – 648 str. : ilustr. ; 25 cm Izv. stv. nasl.: Visokonaponski prekidači. – Bibliografija: str. 623-641. ISBN 978-9958-629-39-6 COBISS.BH-ID 18490886 Printed and bound in Bosnia and Herzegovina by BEMUST, Sarajevo

Mirsad Kapetanović

High Voltage Circuit Breakers.

Editorial Committee: René Peter Paul Smeets (KEMA / Eindhoven University) Lou van der Sluis (Delft University) Piet Knol (KEMA)

MXLIX MC

S

SA

UD

R AJEV

S

O E N SI IE V

U

IO R U M

RA

I V E R SIT A

U

ST

IVERZITE

T

UN

UN

SA

Sarajevo, 2011

Table of Content. Foreword________________________________________________ 13 Acknowledgment_ ________________________________________ 15

1



17 20 20 20 21 22 22 22 22 23 23 23 24 24 24 24 25 25

2

Electric Arc in Gases_ _______________________________ Basic Processes and Physical Characteristics of the Arc_________ 2.1.1 Electron Emission Mechanisms from Metal Surfaces______ 2.1.2 Carriers of Current in the Arc_ _____________________ 2.1.3 Energy Balance on Contacts_______________________ 2.1.4 Mechanisms of Contact Erosion_ ___________________ 2.1.5 Experimental Results of Contact Erosion Studies_________ 2.1.6 Classes of Contact Materials_______________________

27 29 33 36 37 39 42 48

Understanding Switching Devices________________________ 1.1 The Purpose of Switching Devices_________________________ 1.2 Definitions of Switching Devices_ _________________________ 1.2.1 Disconnectors_________________________________ 1.2.2 Earthing Switches_ _____________________________ 1.2.3 High-speed Earthing Switches______________________ 1.2.4 Switches _ ___________________________________ 1.2.5 Make Switches________________________________ 1.2.6 Contactors_ __________________________________ 1.2.7 Fuses _ ___________________________________ 1.2.8 Spark Gaps___________________________________ 1.2.9 Surge Arresters________________________________ 1.2.10 Fault Current Limiters_ __________________________ 1.2.11 Starters _ ___________________________________ 1.2.12 Switching Regulators____________________________ 1.2.13 Electrical Relays_ ______________________________ 1.2.14 Circuit Breakers________________________________ 1.2.15 Disconnecting Circuit Breakers_____________________ The 2.1

5

High Voltage Circuit Breakers.

2.1.6.1 High-conductivity Metals and Alloys___________ 2.1.6.2 Chemically Resistant Metals and Alloys_________ 2.1.6.3 Refractory Metals________________________ 2.1.6.4 Sintered Materials_ ______________________ 2.1.7 Properties of Contact Materials_____________________ 2.2 The Direct-Current Arc_________________________________ 2.2.1 Volt-Ampere Characteristics of Gas-Discharges_ ________ 2.2.2 DC Arc-Quenching______________________________ 2.3 The Alternating-Current Arc_ ____________________________ 2.3.1 Volt-Ampere Characteristics of AC Arcs_______________ 2.3.2 Thermal and Dielectric Breakdown Regions_ ___________ 2.3.3 Arc-conductivity, Power and Energy Dissipation in the Arc Column__

48 51 52 52 52 56 56 58 62 62 64 66

3

69 71 72 75 76 83 85 89 90 92 92 96

Arc Modeling__________________________________________ 3.1 P-T (or Black-Box) Arc Models____________________________ 3.1.1 Mayr and Cassie Equations________________________ 3.1.2 General Form of Dynamic Arc Equation_ ______________ 3.1.3 Survey on Arc Models and Related Parameters__________ 3.1.4 Practical Application of P-T Arc Models_ ______________ 3.1.5 Evaluation of Arc Parameters_ _____________________ 3.1.6 Numerical Treatment____________________________ 3.1.7 Validity Check_________________________________ 3.1.8 Current Zero Measurement________________________ 3.1.8.1 Current Measurement_____________________ 3.1.8.2 Voltage Measurement_____________________ 3.1.8.3 Processing Raw Measured Data into Arc Current and Arc Voltage______________ 3.1.8.4 Performance of a Current Measurement System___ 3.2 Physical Arc Models___________________________________ 3.2.1 General System of Equations of Physical Arc Models______ 3.2.2 Simplified Physical Arc Model with Enthalpy Flow_ _______ 3.2.2.1 Additional Assumptions____________________ 3.2.2.2 System of Equations______________________ 3.2.2.3 Thermodynamic Characteristics of SF6 Plasma ___ 3.2.2.4 Time Dependency of Arc Current_ ____________ 3.2.2.5 Determining the Cross-Section and Arc Voltage___ 3.2.2.6 Determination of the Pressure Distribution Along the Arc Axis_ ______________________

6

96 98 100 102 105 105 106 109 110 110 112

Table of Content.

3.2.2.7 State Equation of SF6 Gas in Stationary and Steady Flow Conditions_ ______ 3.2.2.8 Expressions for Computation of Thermodynamic Characteristics of SF6 Gas__________________ 3.3 Computer Simulation of HV SF6 Circuit Breakers’ Operations_ _____ 3.3.1 Computer Procedure_ ___________________________ 3.3.2 Characteristic Quantities_ ________________________ 3.3.3 Extinction Window______________________________ 3.4 Other Tools for Arc Modeling_____________________________ 3.4.1 Arc Diameter and Arc Temperature_ _________________ 3.4.2 Arc Voltage in Gas and Vacuum_____________________ 3.4.3 Cold Voltage Characteristic________________________ 3.4.4 Limiting Curves________________________________ 3.4.5 Chopping Number______________________________ 3.4.6 Electrical Endurance of Circuit Breakers_______________

118

119 122 122 124 125 126 127 128 132 136 139 142

4

The Vacuum Arc________________________________________ 4.1 Understanding the Vacuum Arc___________________________ 4.1.1 Cathode and Anode Sheath________________________ 4.1.2 The Diffuse and Constricted Vacuum Arc_ _____________ 4.1.2.1 The Diffuse Arc_ ________________________ 4.1.2.2 The Constricted Arc_ _____________________ 4.2 Vacuum Arc Control by Magnetic Field______________________ 4.2.1 The Radial Magnetic Field Principle__________________ 4.2.2 The Axial Magnetic Field Principle___________________

155 157 158 160 161 164 165 166 168

5

173 178 179 183 187 189 190 194 196 196 201 206

Arc-Quenching Media___________________________________ 5.1 Air_______________________________________________ 5.1.1 Arc-Quenching by Arc Elongation in Air_ ______________ 5.1.2 Arc-Quenching by Air-Magnetic Blowing_ _____________ 5.1.3 Arc-Quenching by Compressed Air_ _________________ 5.2 Mineral Oil_ ________________________________________ 5.2.1 Arc-Quenching in Bulk-Oil Circuit Breakers ____________ 5.2.2 Arc-Quenching in Minimum-Oil Circuit Breakers _ _______ 5.3 Sulfur Hexafluoride (SF6)________________________________ 5.3.1 Physical Properties_ ____________________________ 5.3.2 SF6 Decomposition Products_______________________ 5.3.3 Environmental Effects of SF6_______________________

7

High Voltage Circuit Breakers.

5.3.3.1 Ozone Depletion_________________________ 5.3.3.2 Greenhouse Effect_ ______________________ 5.3.3.3 Ecotoxicology and Potential Effects on Health_ ___ 5.3.4 SF6 Substitutes________________________________ 5.4 SF6/N2 Mixtures______________________________________ 5.5 Vacuum_ __________________________________________ 5.5.1 Preserving High Vacuum__________________________ 5.5.2 Use of Vacuum at Higher Voltages___________________ 5.5.3 Contact Materials in Vacuum_______________________



206 208 213 214 216 219 224 225 227

Switching Duties and Transients__________________________ 6.1 Types of Loads_ _____________________________________ 6.1.1 Resistive Load_________________________________ 6.1.2 Capacitive Load________________________________ 6.1.3 Inductive Load_________________________________ 6.1.3.1 Large Inductive Currents: Short circuits_________ 6.1.3.2 Small Inductive Currents___________________ 6.2 Short-circuit Currents__________________________________ 6.2.1 Relation Between Short-circuit Current and Voltage_______ 6.2.2 Percentage DC Component________________________ 6.2.3 RMS and Peak Values of Asymmetrical Current__________ 6.3 Transient Recovery Voltage (TRV)__________________________ 6.3.1 Definition of TRV_______________________________ 6.3.2 Single-Frequency TRV Waveform____________________ 6.3.3 Double-Frequency TRV Waveform___________________ 6.3.4 Two-Parameter Envelopes of TRV_ __________________ 6.3.5 Four-Parameter Envelopes of TRV___________________ 6.3.6 TRV in Circuits with Distributed Circuit Elements_________ 6.3.7 IEEE/ANSI TRV Waveshapes_ ______________________ 6.3.8 TRV in a Three-Phase Network_____________________ 6.3.9 First-Pole-to-Clear Factor_________________________ 6.3.10 Short-Line Fault TRV_ ___________________________ 6.3.11 Initial Transient Recovery Voltage (ITRV)_______________ 6.3.12 TRV, ITRV and SLF______________________________ 6.3.14 Effect of Short-circuit Current Asymmetry on TRV________ 6.3.15 Effect of Arc Voltage on TRV_______________________ 6.3.16 Effect of Current Chopping on TRV___________________ 6.3.17 Effect of Post-Arc Current on TRV___________________ 6.3.18 Effect of Depression on TRV_______________________

233 235 236 237 238 239 241 242 243 244 246 250 250 252 253 254 256 257 260 262 265 266 274 276 281 285 286 286 287

6

8

Table of Content.

6.4 Transients During Switching of Capacitive Currents _ ___________ 6.4.1 Capacitive Circuits______________________________ 6.4.2 Example of Successful Capacitive Current Interruption_____ 6.4.3 Example of Capacitive Current Interruption in Case of a Restrike___ 6.4.4 Voltage Escalation by Successive Restrikes_ ___________ 6.4.5 Chopping of Small Capacitive Currents_______________ 6.4.6 The Influence of Circuit Breakers’ Characteristics on the Switching of Capacitive Currents_______________ 6.4.7 The Influence of Load and Source Side Impedances_ _____ 6.4.8 Capacitive Current Interruption in Three-Phase Circuits____ 6.4.9 Energization of Capacitor Banks_ ___________________ 6.4.10 Energization and Re-Energization of Overhead Lines______ 6.5 Transients During Switching of Small Inductive Currents_ ________ 6.5.1 Chopping of Small Inductive Currents_ _______________ 6.5.2 No-Load Transformer Switching_ ___________________ 6.5.3 Shunt Reactor Switching_ ________________________ 6.5.4 Reignition Phenomenon__________________________ 6.5.5 Overvoltages During Shunt Reactor Switching___________ 6.6 Non-Standardized Switching Duties________________________ 6.6.1 Transformer and Series Reactor Limited Faults__________ 6.6.1.1 Transformer Limited Faults_ ________________ 6.6.1.2 Series Reactor Limited Faults________________ 6.6.2 Short-circuit Currents Without Current Zeros_ __________ 6.6.3 Evolving Fault – Inductive Case_____________________ 6.6.4 Evolving Fault – Capacitive Case____________________ 6.6.5 Parallel Switching of Short-circuit Currents_____________ 6.7 Means of Protection Against Overvoltages_ __________________ 6.7.1 Closing Resistors and Their Function_________________ 6.7.2 Surge Arresters________________________________ 6.7.2.1 Valve Type Surge Arresters_ ________________ 6.7.2.2 Metal Oxide Surge Arresters_ _______________



288 288 289 292 293 294



295 298 299 301 304 306 307 308 310 313 316 321 321 321 324 325 329 330 331 334 336 338 339 340

Operating Principles and Designs of Circuit Breakers_________ 7.1 Requirements of Circuit Breakers_ ________________________ 7.2 Classification of Circuit Breakers__________________________ 7.2.1 Oil Circuit Breakers_ ____________________________ 7.2.2 Air Circuit Breakers_____________________________ 7.2.3 SF6 Circuit Breakers_____________________________

345 347 348 354 358 362

7

9

High Voltage Circuit Breakers.

7.2.3.1 Double Pressure SF6 Circuit Breakers__________ 7.2.3.2 Single-Pressure Puffer Type SF6 Circuit Breakers__ 7.2.3.3 Self-Blast Single Pressure SF6 Circuit Breakers ___ 7.2.3.4 Double Motion Principle_ __________________ 7.2.3.5 Double Speed Principle____________________ 7.2.3.6 SF6 Circuit Breakers with Magnetic Arc Rotation __ 7.2.4 Vacuum Circuit Breakers_ ________________________ 7.3 Operating Mechanisms_________________________________ 7.3.1 Pneumatic Operating Mechanisms_ _________________ 7.3.2 Hydraulic Operating Mechanisms_ __________________ 7.3.3 Spring Operating Mechanisms_ ____________________ 7.3.4 Electro-Magnetic Drives__________________________ 7.3.5 Motor Drives__________________________________ 7.4 Maintenance and Condition Monitoring of Circuit Breakers________ 7.4.1 Choice of Monitored Parameters____________________ 7.4.2 Interpretation of Characteristics Monitored_____________



365 365 373 379 384 387 388 394 397 399 401 403 405 406 409 412

8

Controlled Switching_ __________________________________ 8.1 Principles of Controlled Switching_________________________ 8.1.1 Controlled Opening_ ____________________________ 8.1.2 Controlled Closing______________________________ 8.2 Functional Requirements for Circuit Breakers_________________ 8.2.1 Mechanical Characteristics________________________ 8.2.2 Electrical Characteristics_ ________________________ 8.3 Practical Applications of Controlled Switching_________________ 8.3.1 Controlled Switching of Shunt Capacitor Banks__________ 8.3.2 Controlled Switching of Unloaded Overhead Lines________ 8.3.3 Controlled Switching of Shunt Reactors_______________ 8.3.4 Controlled Switching of Unloaded Transformers__________ 8.4 Reliability Aspects____________________________________ 8.5 Benefits and Economic Aspects___________________________

415 418 419 420 421 421 423 425 426 429 430 432 436 439

9

443 445 449 449 452 455 457

Short-circuit and Switching Tests_________________________ 9.1 High-Power Laboratories_ ______________________________ 9.2 Direct and Indirect Tests________________________________ 9.2.1 Direct Three-Phase Tests_________________________ 9.2.2 Direct Single-Phase Tests_________________________ 9.3 Synthetic Tests_ _____________________________________ 9.3.1 Intervals During the Interrupting Process_ _____________

10

Table of Content.

9.3.2 Intervals During the Making Process_ ________________ 9.3.3 Types of Synthetic Test Methods____________________ 9.3.3.1 Current Injection Methods__________________ 9.3.3.2 Voltage Injection Methods__________________ 9.3.3.3 Three-Phase Synthetic Test Methods_ _________ 9.3.3.4 Synthetic Circuits for Testing UHV Breakers______ 9.3.4 Arc Prolongation Circuit__________________________ 9.3.5 Voltage of the Current Supply Circuit_________________ 9.4 Examples of Short-circuit and Switching Tests_ _______________ 9.4.1 Information to be Included in Test Documents___________ 9.4.2 Short-Time Withstand Current and Peak Withstand Current Test___ 9.4.3 Terminal Fault Tests_____________________________ 9.4.3.1 Test Duty T10__________________________ 9.4.3.2 Test Duty T30__________________________ 9.4.3.3 Test Duty T60__________________________ 9.4.3.4 Test Duty T100s_________________________ 9.4.3.5 Test Duty T100a_________________________ 9.4.4 Critical Current Test Duty_ ________________________ 9.4.5 Single-Phase and Double-Earth Fault Tests_____________ 9.4.6 Short-Line Fault Tests_ __________________________ 9.4.6.1 Test Duty L90_ _________________________ 9.4.6.2 Test Duty L75_ _________________________ 9.4.6.3 Test Duty L60_ _________________________ 9.4.7 Out-of-Phase Tests_ ____________________________ 9.4.7.1 Test Duty OP1_ _________________________ 9.4.7.2 Test Duty OP2_ _________________________ 9.4.8 Capacitive Current Switching Tests_ _________________ 9.4.8.1 Line-Charging Current Switching Tests_________ 9.4.8.2 Cable-Charging Current Switching Tests________ 9.4.8.3 Capacitor Bank Current Switching Tests_ _______ 9.4.9 Inductive Load Switching Test______________________ 9.4.10 Electrical Endurance Tests_ _______________________ 9.4.11 Assessment of Condition After Test_ _________________ 9.4.11.1 No-Load Operations______________________ 9.4.11.2 Inspection_____________________________



459 460 461 465 467 468 473 474 475 478 480 483 484 488 491 495 511 521 521 524 525 538 541 541 541 542 548 550 552 558 559 571 575 575 575

10 Selection of High

voltage Circuit Breakers__________________ 579 10.1 Rated Characteristics Selection___________________________ 581 10.1.1 Rated Voltage_________________________________ 583

11

High Voltage Circuit Breakers.

10.1.2 Rated Insulation Level_ __________________________ 10.1.3 Rated Frequency_______________________________ 10.1.4 Rated Normal Current_ __________________________ 10.1.5 Rated Short-Time Withstand Current_________________ 10.1.6 Rated Peak Withstand Current_ ____________________ 10.1.7 Rated Duration of Short Circuit_____________________ 10.1.8 Rated Short-circuit Making Current__________________ 10.1.9 Rated Short-circuit Breaking Current_________________ 10.1.10 TRV Related to the Rated Short-circuit Breaking Current_ __ 10.1.11 Rated Characteristics for Short-Line Faults_____________ 10.1.12 Rated Characteristics for Out-of-Phase_ ______________ 10.1.13 Rated Operating Sequence________________________ 10.1.14 Rated Time Quantities_ __________________________ 10.1.15 Rated Supply Voltage and Frequency of Auxiliary and Control Circuits_____________________________ 10.1.16 Mechanical Endurance (Class M1 and M2) _ ___________ 10.1.17 Restrike Performance and Capacitive Current Switching Ratings (Class C1 and C2) ___ 10.1.18 Inductive Load Current Switching Ratings______________ 10.1.19 Electrical Endurance (Class E1 and E2) _______________ 10.2 Selection of Service Conditions___________________________ 10.2.1 Normal Service Conditions________________________ 10.2.1.1 Normal Service Conditions for Indoor Installation___ 10.2.1.2 Normal Service Conditions for Outdoor Installation___ 10.2.2 Special Service Conditions________________________ 10.2.2.1 Altitude_______________________________ 10.2.2.2 Pollution_ _____________________________ 10.2.2.3 Ambient Temperature_____________________ 10.2.2.4 Air Humidity____________________________ 10.2.2.5 Ice_ _________________________________ 10.2.2.6 Wind_________________________________ 10.2.2.7 Earthquake_ ___________________________ 10.3 Selection of the Circuit Breaker Type_______________________



584 587 589 592 592 593 593 594 596 601 602 603 603

605 606

607 608 610 611 612 612 613 613 614 616 617 617 618 618 618 619

References________________________________________________ 623 Epilogue __________________________________________________ 643 List of Abbreviations________________________________________ 647

12

Foreword. In 2003, Prof. Mirsad Kapetanović presented his book ”Visokonaponski Prekidači” (“High voltage circuit breakers” in the Bosnian language) to the international experts from CIGRE Study Committee A3 (High Voltage Equipment) at its meeting in Sarajevo. For almost 35 years, Prof. Kapetanović has been active in the research, development and testing of high voltage circuit breakers for Energoinvest, Sarajevo and belongs to the inner circle of “passionate circuit breaking devotees”. I was immediately struck by the depth and detailed coverage of all aspects of breaking and switching, even without mastering the Bosnian language. In 2008, KEMA invited Prof. Kapetanović to prepare an updated and expanded edition of this work, in English. An editorial committee, consisting of Prof. Lou van der Sluis (Delft University), Mr. P. Knol (KEMA) and I (KEMA) supervised the process. This work gives an overview of the present state of the art of circuit breaking: covering its history, the relevant physics of the switching arc, the effects of switching in power systems, the technology and last but not least, testing. In addition, many of KEMA’s proprietary test techniques and methods of presenting test results in reports are described in this edition. Regularly relying on KEMA for certification and research tests for his designs, Prof. Kapetanović's team has a relationship with KEMA that has been built over decades. We learned to appreciate intense discussions on many occasions; questioning at length many well-established principles in testing, e.g. the equivalence of synthetic and direct testing. Prof. Kapetanović was eager to adapt new technologies offered by KEMA, e.g. the current zero technology, to verify the models used in the design of breakers. As a professor at the Faculty of Electrical Engineering of the University of Sarajevo, he is disseminating this knowledge to his students and with this book, to a much larger audience. Testing is solidly built upon the three pillars: standards, competent specialists and adequate test-facilities. Only through this support can testing provide quality verification of component performance.

13

High Voltage Circuit Breakers.

As the world market leader in the field of testing and certification of high voltage equipment, KEMA has strived to maintain this firm position since 1927. The goal of this book is to make the reader aware that high voltage circuit breakers are not “plug and play” devices, and that each specific application has its specialties. Guidance through this extended field of technology is the true mission of the author, the editorial committee and KEMA. Prof. dr. René Smeets KEMA T&D Testing Services Arnhem October 31, 2010

14

High High High voltage voltage voltage circuit circuit circuit breakers. breakers. breakers. High voltage circuit breakers. High voltage circuit breakers. High voltage circuit breakers. Mirsad Kapetanovic

Mirsad Kapetanovic

Mirsad Kapetanovic

www.kema.com www.kema.com www.kema.com

Sarajevo, 2011

Mirsad Mirsad Mirsad Kapetanovic Kapetanovic Kapetanovic