Partial Discharges (PD)

Norasage Pattanadech, PhD, is Associate Professor in the Electrical Engineering Department at King Mongkut Institute of Technology in Bangkok, Thailand. Rainer Haller, PhD, Professor on High Voltage Engineering at Faculty of Electrical Engineering at the University of West Bohemia, Pilsen, Czech Republic.Stefan Kornhuber, PhD, is Professor for High Voltage Engineering at the University of Applied Science, Germany. His research interests include outer and inner electrical interfaces of polymeric materials and the diagnosis.Michael Muhr, PhD, is Emeritus Professor at the Institute of High Voltage Engineering and System Management at the Graz University of Technology in Austria.

• Author Biographies xiForeword xiiiSymbols and Abbreviations xv1 Introduction 11.1 Overview 21.2 Acknowledgments 31.3 Users 32 Physical Behavior of Partial Discharges 52.1 Introduction 52.2 External Discharges 72.2.1 Tip with Negative Polarity 102.2.2 Tip with Positive Polarity 112.3 Internal Discharges 172.3.1 Discharges in Liquid Insulation 172.3.2 Discharges in Solid Insulation 182.4 Gliding Discharges 242.5 PD Quantities 24References 293 Modeling of PD Behavior 333.1 Introduction 333.2 Network-Based Model 333.3 Field-Based Model 423.3.1 Stages of PD Behavior Modeling for DC Conditions 483.3.1.1 Stage 1: Inception of Ionization Processes 483.3.1.2 Stage 2: Establishment of an Electrical Dipole 493.3.1.3 Stage 3: Dissipation of the Electrical Dipole 493.3.2 Extended Modeling Parameters 493.3.3 Summary 52References 534 Measurement of Partial Discharges 554.1 Introduction 554.2 Signal Properties 574.2.1 Device Under Test 574.2.2 High Voltage Circuit 584.3 Coupling Methods 594.3.1 Capacitive Coupling with Measuring Impedance 604.3.2 Inductive Coupling with High-Frequency Current Transformer 654.4 Signal Processing 684.4.1 Full Analog Processing 684.4.2 Semi-Digital Processing 684.4.3 Full Digital Processing 694.5 Measurement Principles 704.5.1 Narrow-Band Measurement 724.5.2 Wide-Band Measurement 764.5.3 Time Domain Integration 794.5.4 Radio Interference Voltage (RIV) Measurement 834.5.5 Synchronous Measurement for Multichannel Application 844.6 Noise Suppression and Reduction 864.6.1 Introduction 864.6.2 Noise Sources 874.6.2.1 Main Sources of Conducted Coupled Noise 874.6.2.2 Blocking Impedance and Filters 884.6.2.3 Electrodes and Wire 884.6.2.4 Coupling Capacitor 884.6.2.5 Floating Potential Elements 884.6.2.6 Pulse-Shaped and Harmonic Noise 894.6.2.7 Noise via Grounding System or Wire Loops 894.6.2.8 Mains Plug and Background Noise of the Measurement Instrument 894.6.3 Denoising Methods 894.6.3.1 Shielding 904.6.3.2 Filters 904.6.3.3 Balanced Bridge Measurements 904.6.3.4 Windowing 924.6.3.5 Gating 934.6.3.6 Clustering 934.7 Visualization and Interpretation of PD Events 964.7.1 Introduction 964.7.2 Classical Methods 974.7.3 Advanced Methods 994.7.4 Pulse Sequence Analysis 1034.8 Artificial Intelligence and Expert Systems 1044.8.1 Introduction 1044.8.2 Artificial Intelligence and Artificial Neural Networks 1054.8.2.1 Learning Process 1074.8.2.2 ANN Architecture 1084.8.2.3 Common Principles 1084.8.2.4 Applications for PD Classification and Localization 1104.8.2.5 Basic Principles of PD Recognition 1104.8.3 Expert System 1164.8.3.1 Introduction 1164.8.3.2 Application for PD Diagnostic 1184.9 Calibration 1194.9.1 Calibration of PD Measuring Circuit 1194.9.2 Performance Test of PD Calibrators 122References 1245 Electromagnetic Methods for PD Detection 1295.1 Introduction 1295.2 PD Measurement by HF and VHF Sensors 1295.2.1 PD Measurement by cc 1295.2.1.1 Theory 1295.2.1.2 cc Characteristics and Installation Aspect for PD Measurement 1335.2.1.3 cc Installation 1345.2.1.4 cc for PD Measurement 1345.2.2 PD Measurement by Inductive Couplers 1375.2.2.1 PD Measurement by High-Frequency Current Transformers 1375.2.2.2 PD Measurement by Rogowski Coil 1415.2.3 PD Measurement by DCS 1445.2.3.1 Theory 1445.2.3.2 DCS Structure and Characteristic 1445.2.3.3 Application of DCS for Cable and Joint PD Measurement 1465.3 PD Measurement by UHF Method 1465.3.1 Theory 1465.3.1.1 General Idea 1465.3.1.2 Propagation and Attenuation of UHF Signal 1475.3.1.3 UHF Signal Attenuation 1505.3.2 UHF Sensors 1505.3.3 UHF PD Measurement System 1545.3.3.1 Sensitivity Verification for GIS PD Measurement 1575.3.3.2 Determination of PD Measurement by UHF PD Technique 1605.3.4 Application of UHF PD Measurement 1615.3.4.1 PD Detection by UHF in GIS and GIL 1615.3.4.2 UHF PD Detection in Transformers 1615.3.4.3 Application of UHF PD Detection to Other High-Voltage Equipment 161References 1646 Non-electrical Methods for PD Measurement 1676.1 Introduction 1676.2 Optical PD Measurement 1676.2.1 Theory 1676.2.2 Principle for Optical PD Measurement Technique 1696.2.3 Application of Optical PD Measurement 1716.2.3.1 Insulators, Transformer Bushings, Surge Arrestors, Transmission Lines, and Fittings 1716.2.3.2 Rotating Machines 1726.3 Acoustic Emission PD Measurement 1726.3.1 Theory 1726.3.2 Acoustic Receivers and Acoustic Sensors 1756.3.2.1 Hand-Held AE PD Receivers 1756.3.2.2 Instrument-Based AE PD Detection 1776.3.3 Acoustic Noises in AE PD Measurement 1836.3.4 General Idea for AE PD Measurement 1846.3.4.1 Sensitivity Check for AE PD Measurement 1846.3.4.2 AE PD Measurement 1846.3.5 Application of Acoustic PD Measurement for High-Voltage Apparatus 1846.3.5.1 Detection of Corona and Surface Discharge from Outdoor Insulators or High- Voltage Conductors 1846.3.5.2 PD Detection in Transformers 1856.3.5.3 PD Detection by AE PD Measurement Technique in GIS and GIL 1856.3.5.4 PD Detection in Rotating Machine by AE PD Measurement Technique 1876.3.5.5 PD Detection for Other High-Voltage Equipment 1886.4 Chemical Byproducts 1886.4.1 Theory 1886.4.2 Dissolved Gas Analysis for Liquid Insulation 1886.4.2.1 Dissolved Gas Generation in Liquid Insulation 1886.4.2.2 Application of DGA for PD Analysis 1896.4.3 Decomposition Gas Analysis 1946.4.3.1 Decomposition SF 6 Analysis for Gas-Insulated High-Voltage Equipment 1946.4.4 Ozone Measurement and Analysis for Air-Cooled Hydrogenerators 195References 1957 PD Localization 1997.1 Introduction 1997.2 The Complexity of PD Localization 1997.3 Classification of PD Localization 2007.3.1 PD Localization for the Internal Insulation 2007.3.2 PD Localization for the External Insulation 2007.4 PD Localization Techniques for the Internal Insulation 2007.4.1 Pulse Time Arrival Method 2017.4.1.1 Concept of Pulse Time Arrival Method 2017.4.1.2 Application of the Pulse Time Arrival Method for PD Localization in High Voltage Equipment 2017.4.2 Auscultatory Method 2057.4.2.1 Concept of Auscultatory Method 2057.4.2.2 Application of the Auscultatory Method for PD Localization in a Transformer 2067.4.3 Triangulation Method 2067.4.3.1 Concept of Triangulation Method 2067.4.3.2 Application of the Triangulation Method for PD Localization in a Transformer 2107.4.4 Bouncing Particle Localization Method 2167.5 PD Localization Techniques for the External Insulation 2177.5.1 Application of the Corona Camera 2177.5.2 Application of the Airborne Acoustic Probe 217References 2188 PD Measurement Under Direct and Impulse Voltage Stress Conditions 2218.1 Introduction 2218.2 PD Measurement at Direct Voltage Conditions 2228.3 PD Measurement at Impulse Voltage Conditions 2298.3.1 PD Measurement at Classical Impulse Voltage Conditions 2308.3.2 PD Measurement at Repetitive Pulse Voltage Conditions 233References 2369 Monitoring of PD Behavior 2399.1 Introduction 2399.2 PD Monitoring 2399.2.1 Off-Line and On-Line PD Measurement 2409.2.1.1 Off-Line PD Monitoring 2409.2.1.2 On-Line PD Monitoring 2429.2.2 PD Monitoring System 2479.2.2.1 PD Sensor 2479.2.2.2 Data Acquisition 2499.3 Application of PD Monitoring 2549.3.1 Application of PD Monitoring for the Existing High-Voltage Equipment 2549.3.2 Application of PD Monitoring for the New Equipment Supporting Smart Grid 2559.4 Challenges for PD Monitoring in Future 256References 25810 Evaluation of PDs 26110.1 Introduction 26110.2 In-House and On-Site PD Testing 26210.2.1 In-House PD Testing 26310.2.2 On-Site PD Testing 26310.3 How to Evaluate PD Test Results 26410.4 Effect of PD on Insulation Degradation 26410.5 Integrity of PD Measurement 26610.6 PD Quantity 26710.6.1 Discharge Magnitude 26710.6.2 PDIV, PDEV, and Other PD Quantities 26710.6.3 PD Quantity as Criteria for Evaluation of Insulation Condition 26810.7 PD Patterns 27010.7.1 Analysis of PD Patterns 27010.7.2 PD Patterns as Criteria for Evaluation of Insulation Condition 27110.8 PD Signal in Time Domain and Frequency Domain Analysis 27510.9 PD Source as Criteria for Evaluation of Insulation Condition 28010.10 Noise Patterns and Noise Reduction 28010.10.1 Noise Patterns 28010.10.2 Noise Reduction 28110.11 Effective Evaluation of PD Phenomena 283References 28411 Standards 28511.1 Standards 28511.2 Technical Brochures 28711.3 Books 289References 28912 Conclusions and Outlook 291Index 293