High Voltage and Electrical Insulation Engineering

Chapter 1: Introduction

• • 1.1 Electric Charge, Discharge, Current, and Potential
• • 1.2 Electric and Magnetic Fields
• • 1.3 Electromagnetism
• • 1.4 Dielectric and Electrical Insulation
• • 1.5 Electrical Breakdown
• • 1.5.1 Global Breakdown
• • 1.5.2 Local Breakdown or Partial Breakdown
• • 1.5.3 Breakdown Strength or Electric Strength
• • 1.6 Corona, Streamer, Star, and Leader
• • 1.6.1 Aurora
• • 1.6.2 Electric Arc
• • 1.7 Capacitance and Capacitor
• • 1.7.1 Stray Capacitance
• • 1.8 Forms of Voltages and Currents
• • 1.8.1 TravelingWaves
• • 1.8.2 Neutral and Ground
• • References

Chapter 2: Electric Fields, Their Control and Estimation

• • 2.1 Electric Field Intensity, “_E_”
• • 2.2 Breakdown and Electric Strength of Dielectrics, “_Eb_”
• • 2.2.1 Partial Breakdown in Dielectrics
• • 2.3 Classification of Electric Fields
• • 2.3.1 Degree of Uniformity of Electric Fields
• • 2.3.1.1 Effect of Grounding on Field Configuration
• • 2.4 Control of Electric Field Intensity (Stress Control)
• • 2.5 Estimation of Electric Field Intensity
• • 2.5.1 Basic Equations for Potential and Field Intensity in Electrostatic Fields
• • 2.5.2 Analytical Methods for the Estimation of Electric Field Intensity in Homogeneous Isotropic Single Dielectric
• • 2.5.2.1 Direct Solution of Laplace Equation
• • 2.5.2.2 “Gaussian Surface” Enclosed Charge Techniques for the Estimation and Optimization of Field
• • 2.5.3 Analysis of Electric Field Intensity in Isotropic Multidielectric System
• • 2.5.3.1 Field with Longitudinal Interface
• • 2.5.3.2 Field with Perpendicular Interface
• • 2.5.3.3 Field with Diagonal Interface
• • 2.5.4 Numerical Methods for the Estimation of Electric Field Intensity
• • 2.5.4.1 Finite Element Method (FEM)
• • 2.5.4.2 Charge Simulation Method (CSM)
• • 2.5.5 Numerical Optimization of Electric Fields
• • 2.5.5.1 Optimization by Displacement of Contour Points
• • 2.5.5.2 Optimization by Changing the Positions of Optimization Charges and Contour Points
• • 2.5.5.3 Optimization by Modification of “Contour Elements”
• • 2.6 Conclusion
• • References

Chapter 3: Field Dependent Behavior of Air and Other Gaseous Dielectrics

• • 3.1 Fundamental Process of Field Assisted Generation of Charge Carriers
• • 3.1.1 Impact Ionization
• • 3.1.2 Thermal Ionization
• • 3.1.3 Photoionization and Interaction of Metastables with Molecules
• • 3.2 Breakdown of Atmospheric Air in Uniform andWeakly Nonuniform Fields
• • 3.2.1 Uniform Field with Space Charge
• • 3.2.2 Development of Electron Avalanche
• • 3.2.3 Development of Streamer or “Kanal Discharge”
• • 3.2.4 Breakdown Mechanisms
• • 3.2.4.1 Breakdown in Uniform Fields with Small Gap Distances (Townsend Mechanism)
• • 3.2.4.2 Breakdown with Streamer (Streamer or Kanal Mechanism)
• • 3.2.5 Breakdown Voltage Characteristics in Uniform Fields (Paschen’s Law)
• • 3.2.6 Breakdown Voltage Characteristics inWeakly Nonuniform Fields
• • 3.3 Breakdown in Extremely Nonuniform Fields and Corona
• • 3.3.1 Development of Avalanche Discharge of Below Critical Amplification
• • 3.3.1.1 Positive Needle–Plane Electrode Configuration (Positive or Anode Star Corona)
• • 3.3.1.2 Negative Needle–Plane Electrode Configuration (Negative or Cathode Star Corona)
• • 3.3.2 Development of Streamer or Kanal Discharge
• • 3.3.2.1 Positive Rod–Plane Electrode (Positive Streamer Corona)
• • 3.3.2.2 Negative Rod–Plane Electrode (Negative Streamer Corona)
• • 3.3.2.3 Symmetrical Positive and Negative Electrode Configurations in Extremely Nonuniform Fields
• • 3.3.3 Development of Stem and Leader Corona
• • 3.3.3.1 Development and Propagation of Positive Leader Corona
• • 3.3.3.2 Development and Propagation of Negative Leader Corona and the Phenomenon of Space Leader
• • 3.3.3.3 Electromagnetic Interference (EMI) Produced by Corona
• • 3.3.4 Summary of the Development of Breakdown in Extremely Nonuniform Fields
• • 3.3.5 Breakdown Voltage Characteristics of Air in Extremely Nonuniform Fields
• • 3.3.5.1 Breakdown Preceded with Stable Star Corona
• • 3.3.5.2 Breakdown Preceded with Stable Streamer Corona
• • 3.3.5.3 Breakdown Preceded with Stable Streamer and Leader Coronas (Long Air Gaps)
• • 3.3.5.4 The Requirement of Time for the Formation of Spark Breakdown with Impulse Voltages
• • 3.3.5.5 Effect of Wave Shape on Breakdown with Impulse Voltages
• • 3.3.5.6 Conclusions from Measured Breakdown Characteristics in Extremely Nonuniform Fields
• • 3.3.5.7 Estimation of Breakdown Voltage in Extremely Nonuniform Fields in Long Air Gaps
• • 3.3.6 Effects of Partial Breakdown or Corona in Atmospheric Air
• • 3.3.6.1 Chemical Decomposition of Air by Corona
• • 3.3.6.2 Corona Power Loss in Transmission Lines
• • 3.3.6.3 Electromagnetic Interference (EMI) and Audible Noise (AN) Produced by Power System Network
• • 3.3.6.4 Other Effects of High Voltage Transmission Lines and Corona on the Environment
• • 3.4 Electric Arcs and Their Characteristics
• • 3.4.1 Static Voltage–Current, _U_–_I_, Characteristics of Arcs in Air
• • 3.4.2 Dynamic _U_–_I_ Characteristics of Arcs
• • 3.4.3 Extinction of Arcs
• • 3.5 Properties of Sulfurhexafluoride, SF6, Gas, and Its Application in Electrical Installations
• • 3.5.1 Properties of Sulfurhexafluoride, SF6 Gas
• • 3.5.1.1 Physical Properties
• • 3.5.1.2 Property of Electron Attachment
• • 3.5.2 Breakdown in Uniform and Weakly Nonuniform Fields with SF6 Insulation
• • 3.5.3 External Factors Affecting Breakdown Characteristics in Compressed Gases
• • 3.5.3.1 Effect of Electrode Materials and Their Surface Roughness on Breakdown
• • 3.5.3.2 Effect of Particle Contaminants in Gas Insulated Systems (GIS)
• • 3.5.3.3 Particle Initiated PB and Breakdown Measurements in GIS
• • 3.5.3.4 Preventive Measures for the Effect of Particles in GIS
• • 3.5.4 Breakdown in Extremely Nonuniform and Distorted Weakly Nonuniform Fields with Stable PB in SF6 Gas Insulation
• • 3.5.5 Electrical Strength of Mixtures of SF6 with Other Gases
• • 3.5.6 Decomposition of SF6 and Its Mixtures in Gas Insulated Equipment
• • 3.5.7 SF6 Gas and Environment
• • 3.5.8 Development in Gas Insulated Power Apparatus
• • 3.5.9 Mineral Oils Versus SF6 Gas
• • 3.5.10 Basic Electrical Insulation Requirements for GITs
• • 3.5.11 SF6 Gas Insulation, a Replacement for Oils
• • 3.5.12 Basic Cooling Requirements Met by Gas for GITs
• • 3.5.13 Environment Concerns and Future Trends
• • 3.6 Investigations for the Requirement of Optimum Clearance for 25 kV Electric Traction: A Case Study
• • 3.6.1 Field Estimation for the Traction Overhead Conductor at 25 kV
• • 3.6.2 Measurement of Breakdown/Withstand Voltage Characteristics
• • 3.6.3 Measurements with ac Power Frequency Voltage
• • 3.6.4 Measurements Under FairWeather, Natural Fog, and Natural Rain Conditions
• • 3.6.5 Measurements Under Artificial Rain
• • 3.6.6 Investigation of the Performance of Air-Gap Under System Overvoltages
• • 3.6.7 Measurements with Impulse Voltages
• • 3.6.8 Measurements with Insulating-Barrier in the Gap
• • 3.6.9 Choice of Solid Insulating Barrier
• • 3.6.10 Positioning and Fastening of the Solid Insulating Barrier in the Gap
• • 3.6.11 Measurement Results with Teflon Sheet as a Barrier
• • 3.7 Conclusions and Recommendations
• • References

Chapter 4: Lightning and Ball Lightning, Development Mechanisms, Deleterious Effects, Protection

• • 4.1 The Globe, a Capacitor
• • 4.1.1 The Earth’s Atmosphere and the Clouds
• • 4.1.1.1 The Troposphere

Chapter 5: Electrical Properties of Vacuum as High Voltage Insulation

Chapter 6: Liquid Dielectrics, Their Classification, Properties, and Breakdown Strength

Chapter 7: Solid Dielectrics, Their Sources, Properties, and Behavior in Electric Fields