Switching in Electrical Transmission and Distribution Systems

René Smeets has for more than 30 years been involved in switching with switchgear ranging from 10–1200 kV. For the last 19 years he has worked at DNV GL (former KEMA) high-power laboratory in the Netherlands. Alongside this he is active in various positions in CIGRE: as convener and member of working groups dealing with switching equipment and testing. He is also a convener of IEC standardization teams with respect to high-voltage switchgear. He is a Fellow of IEEE. Amongst his scientific activities, he is currently chairman of the “Current Zero Club”, an informal group of specialists dealing with current interruption phenomena. He holds a Ph.D. and was appointed as a part-time professor at Eindhoven University in 2001 and adjunct-professor at Xi’an Jiaotong University in 2013. He has been a guest-editor of IEEE Journals and has published numerous papers on switching and testing. He has given courses on switching and switchgear worldwide.   Lou van der Sluis obtained his M.Sc. in electrical engineering from the Delft University of Technology. He joined the KEMA High Power Laboratory in 1977 as a test engineer and was involved in the development of a data acquisition system, computer calculations of test circuits and the digital analysis of test data. Since 1992 he has been employed as a full-time professor at the Delft University of Technology in the Power Systems Department. He is a senior member of IEEE and past convener of CC 03 of CIGRE/CIRED studying the transient recovery voltages in medium and high voltage networks. He is currently a member of CIGRE WG A3.24 on internal arc testing and co-convener of CIGRE WG C4.502 studying the interaction between high-voltage overhead lines and underground cables. He is a member of the advisory board of CIGRE SC A3.Mirsad Kapetanoviæ received the M.Sc. degree in endurance of high-voltage circuit breakers in 1993, and the Ph.D. degree for discovery of Algebra of fractal vector (Bosnian algebra) in 1997 from the Sarajevo University, Bosnia and Herzegovina. He has been with the Energoinvest Electric Power Institute (IRCE), Sarajevo, since 1977. In 1982, he became Head of the high voltage circuit-breakers design department at IRCE. In 1997, he was appointed part-time professor at the Faculty of Electrical Engineering, University of Sarajevo. Currently, he is Professor at the faculty and part-time R&D Manager of EnergoBos Company from Sarajevo. Dr. Kapetanovic is a Member of IEEE, Distinguished Member of CIGRE, regular member of CIGRE Study Commitee SC A3 (High Voltage Equipment), 2002–2008; regular member of SC 13 (Switching Equipment), 1996–2002; and, as of 1990, member of the CIGRE Working Group 13.01 (Practical Application of Arc Physics in Circuit Breakers).David Peelo was born in 1943 in Dublin, Ireland. After completing high school, he studied electrical engineering at University College Dublin and graduated cum laude in 1965. His first employment was at the ASEA High Voltage Laboratory in Ludvika, Sweden. In 1973 he joined BC Hydro in Vancouver, British Columbia, Canada, eventually becoming a switchgear and switching specialist. He took early retirement in 2001 to pursue a new career as an independent consultant and to undertake postgraduate work as represented by this thesis. He obtained a Ph.D. degree in switching with HV air-break disconnectors in 2004. He is active in CIGRE, IEC and IEEE committees and working groups and has authored or co-authored over 40 technical papers.Anton Janssen served 35 years in management functions within the electric transmission and electricity/gas distribution industry, including management responsibility for KEMA High Power Laboratory.  He is active in national and international organizations dealing with technical, managerial and strategic network issues.  He was convener of a number of CIGRE working groups and was special reporter at many CIGRE SC 13/A3 sessions and symposia. Mr Janssen has special interest in the fields of electric transients, in protection and system stability issues, in asset- and life-management issues, in network development and planning, in optimizing the combination of various energy carriers (such as gas, electricity and heat), in the co-operation between utilities and authorities, in optimizing the network and substation topology, in incorporating the volatile sustainable sources of power (electricity, gas and a combination of both) and in coaching Ph.D. students.

“Engineers who design and perform testing of MV and HV circuit breakers, load break switches, or fuses as well as MV and HV test lab managers will find this book to be a very useful and handy reference.”  (IEEE Electrical Engineering magazine, 1 July 2015)

• Preface xv1 Switching in Power Systems 11.1 Introduction 11.2 Organization of this Book 21.3 Power-System Analysis 51.4 Purpose of Switching 81.4.1 Isolation and Earthing 81.4.2 Busbar-Transfer Switching 81.4.3 Load Switching 81.4.4 Fault-Current Interruption 91.5 The Switching Arc 101.6 Transient Recovery Voltage (TRV) 141.6.1 TRV Description 141.6.2 TRV Composed of Load- and Source-Side Contributions 161.7 Switching Devices 191.8 Classification of Circuit-Breakers 22References 272 Faults in Power Systems 282.1 Introduction 282.2 Asymmetrical Current 302.2.1 General Terms 302.2.2 DC Time Constant 332.2.3 Asymmetrical Current in Three-Phase Systems 342.3 Short-Circuit Current Impact on System and Components 352.4 Fault Statistics 432.4.1 Occurrence and Nature of Short-Circuits 432.4.2 Magnitude of Short-Circuit Current 45References 463 Fault-Current Breaking and Making 483.1 Introduction 483.2 Fault-Current Interruption 483.3 Terminal Faults 493.3.1 Introduction 493.3.2 Three-Phase Current Interruption 513.4 Transformer-Limited Faults 583.4.1 Transformer Modelling for TRV Calculation 593.4.2 External Capacitances 613.5 Reactor-Limited Faults 623.6 Faults on Overhead Lines 643.6.1 Short-Line Faults 643.6.2 Long-Line Faults 813.7 Out-of-Phase Switching 813.7.1 Introduction 813.7.2 Switching between Generator and System 833.7.3 Switching between Two Systems 853.8 Fault-Current Making 863.8.1 Impact of Making a Short-Circuit Current on the Circuit-Breaker 863.8.2 Switching-Voltage Transients at Making in Three-Phase Systems 88References 934 Load Switching 964.1 Normal-Load Switching 964.2 Capacitive-Load Switching 974.2.1 Introduction 974.2.2 Single-Phase Capacitive-Load Switching 984.2.3 Three-Phase Capacitive-Load Switching 1044.2.4 Late Breakdown Phenomena 1044.2.5 Overhead-Line Switching 1144.2.6 Capacitor-Bank Energization 1184.3 Inductive-Load Switching 1224.3.1 Current Chopping 1244.3.2 Implication of Current Chopping 1254.3.3 Inductive-Load Switching Duties 127References 1385 Calculation of Switching Transients 1415.1 Analytical Calculation 1415.1.1 Introduction 1415.1.2 Switching LR Circuits 1425.1.3 Switching RLC Circuits 1475.2 Numerical Simulation of Transients 1535.2.1 Historical Overview 1535.2.2 The Electromagnetic Transients Program 1545.2.3 Overview of Electrical Programs for Transient Simulation 1595.3 Representation of Network Elements when Calculating Transients 160References 1626 Current Interruption in Gaseous Media 1646.1 Introduction 1646.2 Air as an Interrupting Medium 1666.2.1 General 1666.2.2 Fault-Current Interruption by Arc Elongation 1676.2.3 Arc Chutes 1716.2.4 Arcs in Open Air 1746.2.5 Current Interruption by Compressed Air 1756.3 Oil as an Interrupting Medium 1766.3.1 Introduction 1766.3.2 Current Interruption in Bulk-Oil Circuit-Breakers 1776.3.3 Current Interruption in Minimum-Oil Circuit-Breakers 1806.4 Sulfur Hexafluoride (SF6) as an Interrupting Medium 1816.4.1 Introduction 1816.4.2 Physical Properties 1826.4.3 SF6 Decomposition Products 1866.4.4 Environmental Effects of SF6 1896.4.5 SF6 Substitutes 1956.5 SF6 – N2 Mixtures 197References 1987 Gas Circuit-Breakers 2027.1 Oil Circuit-Breakers 2027.2 Air Circuit-Breakers 2057.3 SF6 Circuit-Breakers 2077.3.1 Introduction 2077.3.2 Double-Pressure SF6 Circuit-Breakers 2107.3.3 Puffer-Type SF6 Circuit-Breakers 2107.3.4 Self-Blast SF6 Circuit-Breakers 2157.3.5 Double-Motion Principle 2187.3.6 Double-Speed Principle 2207.3.7 SF6 Circuit-Breakers with Magnetic Arc Rotation 221References 2228 Current Interruption in Vacuum 2238.1 Introduction 2238.2 Vacuum as an Interruption Environment 2238.3 Vacuum Arcs 2278.3.1 Introduction 2278.3.2 Cathode- and Anode Sheath 2298.3.3 The Diffuse Vacuum Arc 2308.3.4 The Constricted Vacuum Arc 2348.3.5 Vacuum-Arc Control by Magnetic Field 235References 2419 Vacuum Circuit-Breakers 2439.1 General Features of Vacuum Interrupters 2439.2 Contact Material for Vacuum Switchgear 2469.2.1 Pure Metals 2479.2.2 Alloys 2479.3 Reliability of Vacuum Switchgear 2489.4 Electrical Lifetime 2499.5 Mechanical Lifetime 2499.6 Breaking Capacity 2519.7 Dielectric Withstand Capability 2519.8 Current Conduction 2529.9 Vacuum Quality 2529.10 Vacuum Switchgear for HV Systems 2539.10.1 Introduction 2539.10.2 Development of HV Vacuum Circuit-Breakers 2549.10.3 Actual Application of HV Vacuum Circuit-Breakers 2559.10.4 X-ray Emission 2569.10.5 Comparison of HV Vacuum- and HV SF6 Circuit-Breakers 257References 25810 Special Switching Situations 26110.1 Generator-Current Breaking 26110.1.1 Introduction 26110.1.2 Generator Circuit-Breakers 26610.2 Delayed Current Zero in Transmission Systems 26710.3 Disconnector Switching 26710.3.1 Introduction 26710.3.2 No-Load-Current Switching 26810.3.3 Bus-Transfer Switching 27810.4 Earthing 27910.4.1 Earthing Switches 27910.4.2 High-Speed Earthing Switches 28010.5 Switching Related to Series Capacitor Banks 28210.5.1 Series Capacitor-Bank Protection 28210.5.2 By-Pass Switch 28310.6 Switching Leading to Ferroresonance 28510.7 Fault-Current Interruption Near Shunt Capacitor Banks 28610.8 Switching in Ultra-High-Voltage (UHV) Systems 28810.8.1 Insulation Levels 28910.8.2 UHV System Characteristics Related to Switching 28910.9 High-Voltage AC Cable System Characteristics 29110.9.1 Background 29110.9.2 Current Situation 29110.10 Switching in DC Systems 29510.10.1 Introduction 29510.10.2 Low- and Medium Voltage DC Interruption 29510.10.3 High-Voltage DC Interruption 29710.11 Distributed Generation and Switching Transients 29810.11.1 General Considerations 29810.11.2 Out-of-Phase Conditions 30010.12 Switching with Non-Mechanical Devices 30110.12.1 Fault-Current Limitation 30110.12.2 Fuses 30110.12.3 IS Limiters 303References 30411 Switching Overvoltages and Their Mitigation 31011.1 Overvoltages 31011.2 Switching Overvoltages 31211.3 Switching-Voltage Mitigation 31311.3.1 Principles of Mitigation 31311.3.2 Mitigation by Closing Resistors 31411.3.3 Mitigation by Surge Arresters 31611.3.4 Fast Insertion of Shunt Reactors 31911.4 Mitigation by Controlled Switching 32011.4.1 Principles of Controlled Switching 32011.4.2 Controlled Opening 32111.4.3 Controlled Closing 32311.4.4 Staggered Pole Closing 32411.4.5 Applications of Controlled Switching 32411.4.6 Comparison of Various Measures 33411.4.7 Influence of Metal-Oxide Surge Arresters on Circuit-Breaker TRVs 33611.4.8 Functional Requirements for Circuit-Breakers 33711.4.9 Reliability Aspects 34011.5 Practical Values of Switching Overvoltages 34111.5.1 Overhead Lines 34111.5.2 Shunt Capacitor Banks and Shunt Reactors 342References 34412 Reliability Studies of Switchgear 34712.1 CIGRE Studies on Reliability of Switchgear 34712.1.1 Reliability 34712.1.2 Worldwide Surveys 34812.1.3 Population and Failure Statistics 34912.2 Electrical and Mechanical Endurance 35412.2.1 Degradation Due to Arcing 35412.2.2 Electrical-Endurance Verification 35612.2.3 Mechanical Endurance 35812.3 CIGRE Studies on Life Management of Circuit-Breakers 35912.3.1 Maintenance 35912.3.2 Monitoring and Diagnostics 36012.3.3 Life Management of Circuit-Breakers for Frequent Load-Switching 36212.4 Substation and System Reliability Studies 362References 36313 Standards, Specification, and Commissioning 36513.1 Standards for Fault-Current Breaking Tests 36513.1.1 Background and History of the Standardized IEC TRV Description 36613.1.2 IEC TRV Description 36813.1.3 IEC Test-Duties 37013.1.4 IEC TRV Parameters Selection and Application 37313.2 IEC Standardized Tests for Capacitive-Current Switching 37313.3 IEC Standardized Tests for Inductive-Load Switching 37713.3.1 Shunt-Reactor Switching 37813.3.2 Medium-Voltage Motor Switching 38113.4 Specification and Commissioning 38113.4.1 General Specifications 38113.4.2 Circuit-Breaker Specification 38313.4.3 Information to be given with Requests for Offers 38413.4.4 Information to be provided with Submitted Offers 38413.4.5 Circuit-Breaker Selection 38413.4.6 Circuit-Breaker Commissioning 384References 38514 Testing 38614.1 Introduction 38614.2 High-Power Tests 38714.2.1 Introduction 38714.2.2 Direct Tests 39114.2.3 Synthetic Tests 395References 411List of Abbreviations 413Index 417