Gas-Insulated

Substations

Edited by Hermann Koch

GISGas-Insulated Substations

Editor

Koch

www.wiley.com

Also available as an e-book

Gas-Insulated Substations is an all-inclusive reference guide to gas insulated substations (GIS) which takes account of its basic principles, technology, application, design specification, testing and ownership issues. Practical and theoretical aspects are handled by acknowledged GIS experts who have been involved with the technology from the start. They provide the reader with the knowledge needed to identify a project with GIS, manage the GIS process and then assemble and later maintain that system. This learning resource offers engineering students and manufacturing professionals a sound insight into this important technology at a time when application of GIS is spreading as fresh projects are being launched and more companies are becoming involved.

Key features:

• Written by leading GIS experts who have been involved in the development of the technology since its invention.

• Discusses both the practical and theoretical aspects of GIS.• Details advanced and basic material, accessible for both existing GIS users

and those planning to implement the technology.• Chapters are written as tutorials and provide helpful references for further

reading and study.• Invaluable guide to practicing electrical, mechanical and civil engineers as

well as third and fourth year electric power engineering students.• A companion website hosting full colour versions of the figures in the book.

Edited byHermann KocH Energy Transmission, Siemens AG, Germany

Gas-Insulated Substations

ISBN 978-1-118-57072-2

26.8 mm

www.wiley.com/go/koch/substations

GIS

GIS

GAS INSULATEDSUBSTATIONS

GAS INSULATEDSUBSTATIONS

Edited by

Hermann KochEnergy Transmission, Siemens AG, Germany

A co-publication of IEEE Press and John Wiley & Sons Ltd

This edition first published 2014 2014 John Wiley and Sons Ltd

Registered officeJohn Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, United Kingdom

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Limit of Liability/Disclaimer of Warranty: While the publisher and author have used their best efforts in preparing thisbook, they make no representations or warranties with respect to the accuracy or completeness of the contents of this bookand specifically disclaim any implied warranties of merchantability or fitness for a particular purpose. It is sold on theunderstanding that the publisher is not engaged in rendering professional services and neither the publisher nor the authorshall be liable for damages arising herefrom. If professional advice or other expert assistance is required, the services of acompetent professional should be sought

Library of Congress Cataloging-in-Publication Data

Gas insulated substations / edited by Hermann J. Koch.pages cm

Includes bibliographical references and index.ISBN 978-1-118-57072-2 (hardback)

1. Electric cables–Gas insulation. 2. Electric substations. I. Koch,Hermann, 1954- editor of compilation.

TK3441.G3G37 2014621.310042–dc23

2014002202

A catalogue record for this book is available from the British Library.

ISBN: 9781118570722

Set in 10/12pt TimesLTStd-Roman by Thomson Digital, Noida, India.

Contents

List of Contributors xv

Foreword xvii

Acknowledgements xix

1 Introduction 1Hermann Koch and John Brunke

1.1 General 11.1.1 Organization 11.1.2 Experts over the Years 31.1.3 Content of the Tutorial 31.1.4 Tutorials and Panels Given 4

1.2 Definitions 41.2.1 GIS 41.2.2 Metal-Enclosed Switchgear and Controlgear 51.2.3 Gas Insulated Metal-Enclosed Switchgear 51.2.4 Gas Insulated Switchgear Enclosure 61.2.5 Compartment of GIS 61.2.6 Design Pressure of Enclosures 61.2.7 Gas Monitoring Systems 61.2.8 Gas Leakage Rate (Absolute) 61.2.9 Gas Leakage Rate (Relative) 61.2.10 Gas Pass Through Insulator 71.2.11 Gas Zone 71.2.12 Local Control Cubicle (or Cabinet) (LCC) 71.2.13 Support Insulator 71.2.14 Partition 71.2.15 Power Kinematic Chain 71.2.16 Design Pressure of Enclosures 71.2.17 Relative Pressure across the Partition 71.2.18 Operating Pressure of Pressure Relief Device 71.2.19 Routine Test Pressure of Enclosures and Partitions 8

1.2.20 Type Test Pressure of Enclosures and Partitions 81.2.21 Rated Filling Pressure pre 81.2.22 Bushing 81.2.23 Main Circuit 81.2.24 Auxiliary Circuit 81.2.25 Design Temperature of Enclosures 81.2.26 Service Period 81.2.27 Transport Unit 81.2.28 Mixed Technologies Switchgear (MTS) 9

1.3 Standards and References 91.3.1 Standards 91.3.2 Current Standards Most Relevant to GIS 10

1.4 Ratings 141.4.1 General 141.4.2 Rated Maximum Voltage 141.4.3 Rated Insulation Level 141.4.4 Rated Power Frequency 151.4.5 Rated Continuous Current 161.4.6 Rated Short Time Withstand Current 161.4.7 Rated Peak Withstand Current 161.4.8 Rated Supply Voltages 17

2 Basic Information 18Hermann Koch, John H. Brunke, and John Boggess

2.1 History 182.1.1 General 182.1.2 Steps of Development 19

2.2 Physics of Gas Insulated Switchgear 342.2.1 Electric Fields 342.2.2 Breakdown in Gases 362.2.3 Excitation and Ionization 362.2.4 Free Electrons 362.2.5 Mean Free Path 372.2.6 Electron/Gas Molecule Impact 372.2.7 Breakdown 372.2.8 Sulfur Hexafluoride 382.2.9 Electric Field Control in GIS 382.2.10 GIS Circuit Breakers 40

2.3 Reliability and Availability 402.3.1 General 402.3.2 Historical View 412.3.3 CIGRE Survey 422.3.4 Reliability GIS versus AIS 49

2.4 Design 502.4.1 Overview 502.4.2 SF6 Gas 50

vi Contents

2.4.3 Enclosure 522.4.4 Principles 522.4.5 Operation 52

2.5 Safety 532.5.1 General 532.5.2 Design and Erection Requirements 532.5.3 Building Requirements 582.5.4 Grounding/Earthing Requirements 602.5.5 Burn Through of Enclosure 602.5.6 Work Behind Pressurized Insulators 602.5.7 SF6 Release to Buildings 60

2.6 Grounding and Bonding 622.6.1 General 622.6.2 GIS Versus AIS Grounding 622.6.3 GIS Enclosure Currents 622.6.4 General Rules for GIS Grounding 642.6.5 Very Fast Transients 642.6.6 GIS Grounding Connection Details 64

2.7 Factors for Choosing Gas Insulated Substations 662.7.1 General 662.7.2 Factors 672.7.3 Power System 702.7.4 Environment 702.7.5 Economics 702.7.6 Conclusion 70

2.8 Sulfur Hexafluoride (SF6) 712.8.1 What is Sulfur Hexafluoride? 712.8.2 Background Information 742.8.3 Producer and User of SF6 812.8.4 SF6 Gas Handling 852.8.5 Gas-Handling Equipment 982.8.6 Life Cycle Assessment Case Study: Würzburg 1032.8.7 Kyoto Protocol 1062.8.8 Requirements for the Use of SF6 108References 108

3 Technology 110Hermann Koch, George Becker, Xi Zhu, and Devki Sharma

3.1 General 1103.1.1 Materials 1103.1.2 Steel 1113.1.3 Aluminum 112

3.2 Modular Components, Design, and Development Process 1133.2.1 Modular Design 1133.2.2 Design Features 1253.2.3 Design Process 129

Contents vii

3.3 Manufacturing 1303.3.1 General 1303.3.2 GIS Factory 1313.3.3 Insulating Parts 1323.3.4 Operation Rods and Tubes 1343.3.5 Machining of the Enclosure 1363.3.6 Cleaning and Degreasing 1363.3.7 Pressure and Gas Tightness Test 1373.3.8 Painting Enclosures 1393.3.9 Preassembly of Functional Units 1393.3.10 Final Assembly 1403.3.11 Quality Insurance 1423.3.12 Regional Manufacturing 142

3.4 Specification Development 1423.4.1 Introduction 1423.4.2 Specification Documentation 143

3.5 Instrument Transformers 1713.5.1 Current Transformers 1713.5.2 Voltage Transformers 1733.5.3 Transient Overvoltages of a CT and VT 174

3.6 Interfaces 1753.6.1 Direct Connection between Power Transformers and GIS 1753.6.2 Cable Connections for Gas Insulated Switchgear for Rated

Voltage above 52 kV 1803.6.3 Bushings 183

3.7 Gas Insulated Surge Arresters 1853.8 Gas Insulated Bus 186

3.8.1 General 1863.8.2 Three-Phase Insulated Bus Duct 1873.8.3 Single-Phase Insulated Bus Duct 1883.8.4 Bus Duct to Connect Overhead Lines 1893.8.5 Bus Duct to Connect Circuit Breakers 1903.8.6 Bus Duct to Connect Transformers 1913.8.7 Bus Duct to Connect Cables 1923.8.8 Bus Duct to Underpass Overhead Lines 1933.8.9 Bus Duct Above Ground 1943.8.10 Bus Duct Trench Laid 1973.8.11 Bus Duct Laid in a Tunnel 1973.8.12 Bus Duct Directly Buried 2013.8.13 Shipment on Site 2043.8.14 Assembly on Site 204References 205

4 Control and Monitoring 206Hermann Koch, Noboru Fujimoto, and Pravakar Samanta

4.1 General 2064.2 GIS Monitoring 207

viii Contents

4.2.1 Gas Monitoring 2074.2.2 Partial Discharge 2094.2.3 PD Monitoring Strategies 2134.2.4 Circuit Breaker Monitoring 2144.2.5 Other Monitoring 215

4.3 Local Control Cabinet 2154.3.1 General 2154.3.2 Bay Controller 2194.3.3 Control Schemes 220

4.4 Digital Communication 2214.4.1 General 2214.4.2 Basic Digital Communication Standard 2224.4.3 Switchgear Related Communication Standard 2254.4.4 Normative References 2304.4.5 Classifications 231References 233

5 Testing 235

5.1 General 2355.2 Type Tests 235

5.2.1 Dielectric Tests 2365.2.2 Measurement of the Resistance of the Main Circuits 2365.2.3 Temperature Rise Tests 2375.2.4 Short-Time Withstand Current and Peak Withstand

Current Tests 2375.2.5 Tightness Tests 2385.2.6 Low and High Temperature Tests 2385.2.7 Proof Tests for Enclosures 2395.2.8 Circuit Breaker Design Tests 2395.2.9 Switch Operating Mechanical Life Tests 240

5.3 Routine Tests 2415.3.1 Dielectric Tests 2415.3.2 Measurement of the Resistance of the Main Circuits 2415.3.3 Tightness Tests 2415.3.4 Pressure Tests of Enclosures 2425.3.5 Mechanical Operation Tests 2435.3.6 Tests on Auxiliary and Control Circuits 2435.3.7 Pressure Tests on Partitions 243

5.4 On-Site Field Testing 2435.4.1 Gas Leakage and Gas Quality (Moisture, Purity, and Density) 2435.4.2 Electrical Tests: Contact Resistance 2445.4.3 Electrical Tests: AC Voltage Withstand 2445.4.4 Electrical Tests: AC Voltage Withstand Requirements

and Conditions 2455.4.5 Electrical Tests: AC Voltage Withstand Configurations

and Applications 245

Contents ix

Peter Grossmann and Charles L Hand

5.4.6 Electrical Tests: DC Voltage Withstand Tests 2455.4.7 Mechanical and Electrical Functional and

Operational Tests 2455.4.8 Connecting the GIS to the Electrical System 246References 246

6 Installation 247Hermann Koch, Richard Jones, and James Massura

6.1 General 2476.2 Installation 248

6.2.1 Introduction 2486.2.2 Safety Considerations and Assembly Tips 2486.2.3 General Project Planning Outline 2486.2.4 Future GIS Expansion Considerations 2496.2.5 Advance Planning and Preliminary

Site Evaluation 2496.2.6 Training 2566.2.7 Material Receipt and Control 2576.2.8 Installation/Assembly Instructions 2596.2.9 Gas Insulated Substation Tests 2716.2.10 Commissioning, Energization, and Outage Plan 2786.2.11 Maintenance and Turnover Documents 279

6.3 Energization: Connecting to the Power Grid 2806.3.1 Grid Connection Considerations (Long-Term Planning) 2806.3.2 GIS Grounding System 2806.3.3 Gas Zones 2806.3.4 Operational Considerations 281

7 Operation and Maintenance 282

and Ravi Dhara7.1 General 2827.2 Operation of a Gas Insulated Substation 283

7.2.1 General 2837.2.2 Circuit Breaker 2837.2.3 Disconnect Switches 2857.2.4 Nonfault-Initiating Grounding Switches 2867.2.5 High Speed (Fault-Initiating) Grounding Switches 2887.2.6 Three-Position Disconnect/Grounding Switches 2897.2.7 Switch Viewports 2927.2.8 Gas Compartments and Zones 2927.2.9 Interlocking 2937.2.10 Local Control Cabinets (LCCs) 2967.2.11 Alarms 2987.2.12 Switching a GIS 2997.2.13 Conclusion 301

x Contents

Hermann Koch, Charles L Hand, Arnaud Ficheux, Richard Jones,

7.3 Maintenance 3027.3.1 General 3027.3.2 Common Maintenance Procedures 302

7.4 SF6 Gas Leakage Repair 3037.5 Repair 306

7.5.1 Nature and Sources of Faults 3067.5.2 Repair Times and Service Continuity 3067.5.3 Examples of Repair 307

7.6 Extensions 3077.6.1 General 3077.6.2 Work To Be Done When an Extension Is Planned from

Initial Design Stage 3087.6.3 Work To Be Done When an Extension Is Not Anticipated

from Initial Design Stage 3097.6.4 Service Continuity During Extension Work 3107.6.5 Testing of Interface 311

7.7 GIS Retrofit or Upgrade 3117.7.1 Introduction 3117.7.2 Challenges with Old GIS 3127.7.3 Retrofit or Upgrade 312

7.8 Overloading and Thermal Limits 3157.8.1 General 3157.8.2 Design for Continuous Rating Current 3177.8.3 Determination of the Limits 3177.8.4 Maximum Continuous Load Current 3187.8.5 Short-Time Overload Capability 3187.8.6 Equations/Formulae to Calculate Overloads 318

8 Applications 321Hermann Koch, Peter Grossmann, Arun Arora, and Dave Solhtalab

8.1 General 3218.2 Typical GIS Layouts 321

8.2.1 Single Bus Arrangement 3228.2.2 Double Bus Arrangement 3228.2.3 Ring Bus Arrangement 3228.2.4 H-Scheme Arrangement 3228.2.5 Breaker and a Half Arrangement 323

8.3 Reference Projects 3248.3.1 500 kV Indoor GIS and 115 kV AIS 3248.3.2 115 kV GIS Switching Station 3278.3.3 345 kV and 4000 A Indoor Expendable Ring Bus GIS 3338.3.4 69 kV and 3150 A Indoor Double Bus GIS 3378.3.5 115 kV and 1200 A Container Ring Bus GIS 3388.3.6 115 kV and 2000 A Outdoor Single Bus GIS 3418.3.7 345 kV and 4000 A Indoor Breaker and Half-Scheme GIS 3448.3.8 115 kV and 3150 A Indoor Ring Bus GIS 349

Contents xi

8.3.9 69 kV and 2000 A Indoor Ring Bus GIS 3528.3.10 138 kV and 230 kV Outdoor Ring Bus GIS 3558.3.11 500 kV and 4000 A/8000 A Indoor Breaker and Third GIS 3578.3.12 69 kV and 1600 A Outdoor Single Bus GIS 3638.3.13 69 kV and 2000 A Underground GIS 3648.3.14 69 kV GIS under Severe Environment 369

8.4 GIS Case Study 3718.4.1 Public Service Electric and Gas Company – New Jersey 371

8.5 Mobile GIS 3768.5.1 General 3768.5.2 Containerized GIS 3778.5.3 Truck-Mounted GIS 379

8.6 Mixed Technology Switchgear (MTS) 3858.6.1 Introduction 3858.6.2 Definition of MTS 3868.6.3 MTS Design Features and Applications 3888.6.4 MTS Application Examples 3908.6.5 Conclusion 390

8.7 Future Developments 3908.7.1 Reduction of Size 3908.7.2 Simpler Design 3948.7.3 Life Cycle Cost Evaluations 3948.7.4 Functional Specification 3958.7.5 Intelligent GIS 3958.7.6 Integrated Electronic Devices 3958.7.7 Rogowski Coil 3968.7.8 Capacitive Divider 397References 399

9 Other Topics 400Hermann Koch, Venkatesh Minisandram, Arnaud Ficheux,George Becker, Noboru Fujimoto, and Jorge Márquez-Sánchez

9.1 General 4009.2 Environment 401

9.2.1 Environmental Life Cycle Assessment 4019.2.2 GIS Environmental Impact 4049.2.3 Environmental Impact 410

9.3 Life Cycle Cost Analysis 4129.3.1 Introduction 4129.3.2 Scope 4139.3.3 Coordination 4139.3.4 Methodology 4139.3.5 Procedure 4169.3.6 Finalized LCCA 4189.3.7 Reliability, Availability, Failure Rates,

and Cost 420

xii Contents

9.4 Insulation Coordination Study 4219.4.1 General 4219.4.2 Overvoltages 4229.4.3 Grounding 426

9.5 Very Fast Transients 4269.5.1 General 4269.5.2 Very Fast Transients in GIS 4269.5.3 Transient Enclosure Voltage 432

9.6 Project Scope Development 4379.6.1 Engineering Planning 4379.6.2 Planning the GIS Project Construction and Installation 4389.6.3 Site Preparation 4399.6.4 Installation of the New GIS 4409.6.5 Installation of GIS Extensions 4419.6.6 Equipment Access 441

9.7 Risk-Based Asset Management of Gas Insulated Substations and Equipment 4419.7.1 Introduction 4419.7.2 Scope 4419.7.3 Methodology 4419.7.4 Assessing Risk 446

9.8 Health and Safety Impact 4519.8.1 Risk of Burning 4519.8.2 Risk of Breathing Toxic Gases 4519.8.3 Risk of Touching Toxic Materials 4529.8.4 Risk of Electric Shock 452

9.9 Electromagnetic Field 4529.9.1 General 4529.9.2 Electric Field in Operation 4529.9.3 Electric Field during Short Circuit 4529.9.4 Magnetic Field in Operation 4539.9.5 Magnetic Field during Short Circuit 453

9.10 SF6 Decomposition Byproducts 4539.10.1 General 4539.10.2 Byproducts and Toxicity 4549.10.3 Impact on Worker Protection 4559.10.4 Gas Analysis 455References 456

10 Conclusion 458Hermann Koch

Further Reading 459Devki Sharma

Index 463

Contents xiii