Autorentext

Greg C. Stone has a PhD in electrical engineering with over 45-years' experience in performing PD testing on rotating machines and other equipment for a large electric power utility; as well as with PD equipment manufacturer Iris Power L.P., which he co-founded. He has many technical awards for his work from the IEEE, CIGRE, IEC and EPRI, and is an IEEE Fellow.

Andrea Cavallini, PhD, is with the University of Bologna, Italy where he has researched PD theory and PD test methods for 24 years, particularly for power cables, stator windings and other HV equipment. He was also a co-founder of TechImp S.r.L, a manufacturer of PD test equipment. He has over 200 papers in the PD field, including the development of the TF map method for noise and PD source identification. He is an IEEE Fellow.

Glenn Behrmann worked for over 20 years on PD measurements for GIS and rotating machines at ABB in Switzerland and its successor companies. He has been active in creating CIGRE Technical Brochures in this area, written many papers in the field, as well as helping to lead the efforts to draft IEC 62478, and revise IEC 60270 and IEEE 454. He has a BSEE from Union College in the USA.

Claudio Angelo Serafino is head of the Test and Measurement Department for Terna S.p.A, the Italian transmission grid utility. He is an expert with 40-years' experience on power transformer condition assessment using PD and other technologies.

Klappentext

Accessible reference dealing with (partial discharge) PD measurement in all types of high voltage equipment using modern digital PD detectors Practical Partial Discharge Measurement on Electrical Equipment is a timely update in the field of partial discharges (PD), covering both holistic concepts and specific modern applications in one volume. The first half of the book educates the reader on what PD is and the general principles of how it is measured and interpreted. The second half of the book is similar to a handbook, with a chapter devoted to PD measurements in each type of high voltage (HV) equipment. These chapters contain specific information of the insulation system design, causes of PD in that equipment, off-line and on-line measurement methods, interpretation methods, and relevant standards. The work is authored by four well-known experts in the field of PD measurement who have published hundreds of technical papers on the subject and performed thousands of PD measurements on all the different types of HV equipment covered in the book. The authors have also had relationships with PD detector manufacturers, giving them key insights into test instruments and practical measurements. Sample topics covered in the work include:

• Physics of PD, discharge phenomena (contact sparking and vibration sparking), and an introduction to PD measurement (electrical, optical, acoustic, and chemical)
• Electrical PD detection (types of sensors), RF PD detection (antenna, TEV), and PD instrumentation and display
• Off-line and on-line PD measurements, general principles of PD interpretation, and laboratory PD testing of lumped test objects

• PD in different types of HV equipment (power cables, power transformers, air insulated metal-clad switchgear, rotating machines, gas-insulated switchgear, and more) For HV equipment OEMs, users of HV equipment, or employees of companies that provide PD testing services to clients, Practical Partial Discharge Measurement on Electrical Equipment is an essential reference to help understand general concepts about the topic and receive expert guidance during specific practical applications.

  Inhalt

  About the Authors xvii

  Preface xix

  Acknowledgments xx

  Acronyms xxi

  1 Introduction 1

  1.1 Why Perform Partial Discharge Measurements? 1

  1.2 Partial Discharge and Corona 2

  1.3 Categories of PD Tests 3

  1.3.1 Factory PD Testing 3

  1.3.2 Onsite/Off line PD Tests 5

  1.3.3 Online PD Testing and Continuous Monitoring 5

  1.4 PD Test Standards 6

  1.5 History of PD Measurement 7

  1.5.1 RIV Test - The First Era 7

  1.5.2 Analog PD Detection Using Oscilloscopes - The Second Era 9

  1.5.3 Digitizing, Ultrahigh Frequency, and Post- Processing - The Third Era 11

  1.5.3.1 Transition to Digital Instruments 11

  1.5.3.2 VHF and UHF PD Detection 12

  1.5.3.3 Post- Processing of Signals 14

  1.6 The Future 15

  1.7 Roadmap for the Book 16

  References 17

  2 Electric Fields and Electrical Breakdown 21

  2.1 Electric Fields in High- Voltage Equipment 21

  2.1.1 Impact of Electric Field on Partial Discharges 21

  2.1.2 Basic Quantities and Equations 21

  2.1.3 Simple Electrode Configurations 22

  2.1.3.1 Parallel Plates Capacitor 24

  2.1.3.2 Coaxial Cylindrical Electrodes 24

  2.1.3.3 Concentric Spheres 25

  2.1.3.4 Point/Plane Electrodes 25

  2.1.4 Multi- Dielectric Systems 25

  2.1.4.1 Cavities (Voids) 26

  2.1.4.2 Interfaces 28

  2.1.4.3 Triple Point (Triple Junction) 29

  2.1.5 Floating Metal Objects 30

  2.2 Electrical Breakdown 30

  2.3 Breakdown in Gases 31

  2.3.1 Breakdown in Uniform Fields 31

  2.3.2 Breakdown in Divergent Fields 36

  2.3.3 Breakdown Under Impulse Voltages - the V- t Characteristic 37

  2.4 Breakdown in Solids 38

  2.4.1 Electrical Treeing 40

  2.5 Breakdown in Liquids 41

  2.6 Dielectric Strength 43

  References 45

  3 Physics of Partial Discharge 47

  3.1 Introduction 47

  3.2 Classification of Partial Discharges 47

  3.3 PD Current Pulse Characteristics 48

  3.4 Effects of PD 53

  3.5 Corona Due to Non- Uniform Electric Fields Around Conductors 55

  3.5.1 PD and Corona Polarity 56

  3.5.2 Corona AC Phase Position 57

  3.5.3 Corona Current Pulse Characteristics 57

  3.6 Partial Discharge in Voids 59

  3.6.1 PD Inception 59

  3.6.1.1 Inception Delay 61

  3.6.2 Modified Field Due to Space Charge 62

  3.7 PD on Insulation Surfaces 66

  3.7.1 Triple Point Junction 66

  3.7.2 Electrical Tracking 66

  3.8 Effect of Ambient Conditions and Conditioning 67

  3.8.1 Conditioning 67

  3.8.2 Ambient/Operating Conditions 68

  3.9 Summary of Measured PD Quantities 68

  3.9.1 Magnitude 69

  3.9.2 Pulse Count Rate 69

  3.9.3 Phase Position 70

  3.10 Understanding the PD Pattern with Respect to the AC Cycle 71

  3.10.1 Polarity Analysis 71

  3.10.2 Physical Basis for PRPD Patterns 71

  3.10.3 PD Packets 80

  References 82

  4 Other Discharge Phenomena 85

  4.1 Introduction 85

  4.2 PD as Interference 86

  4.3 Circuit Breaker Arcing 87

  4.4 Contact Arcing and Intermittent Connections 87

  4.5 Metal Oxide Layer Breakdown 89

  4.6 Dry Band Arcing 89

  4.7 Glow (or Pulseless) Discharge 89

  References 90

  5 PD Measurement Overview 93

  5.1 Introduction 93

  5.2 Charge- Based and Electromagnetic Measurement Methods 93

  5.3 Optical PD Detection 95

  5.4 Acoustic Detection of PD 97

  5.4.1 Acoustic Detection of PD Through the Air 98

  5.4.2 Acoustic PD Detection Within Enclosed HV Apparatus 102

  5.4.2.1 Power Transformers 102

  5.4.2.2 Gas- Insulated Switchgear and Isolated Phase Bus 104

  5.5 Chemical Detection 105

  5.5.1 Ozone in Air 105

  5.5.2 Dissolved Gas Analysis (DGA) 106

  5.5.3 SF 6 Decomposition Products in GIS 107

  References 107

  6 Charge- Based PD Detection 109

  6.1 Introduction 109

  6.2 Basic Electrical Detection Circuits Using Coupling Capacitors 109

  6.2.1 Direct Circuit 110

  6.2.2 Indirect Circuit 111

  6.3 Measuring Impedances 111

  6.3.1 Resistors and Quadripoles 111

  6.3.2 AC Synchronization and Quadripoles 113

  6.3.3 High- Frequency Current Transformers 113

  6.4 Electrical PD Detection Models 115

  6.4.1 ABC Model 115

  6.4.1.1 Equivalent Circuit 117

  6.4.1.2 Equivalent PD Current Generator 117

  6.4.1.3 Coupling Capacitor 117

  6.4.1.4 Under Estimation of Charge 118

  6.4.2 Dipole Model 118

  6.4.3 Comparing the ABC Model with the Dipole Model 120

  6.4.4 Pulse Polarity 120

  6.5 Quasi- integration in Charge- Based Measuring Systems 121

  6.5.1 Quasi- integration Explai…