Methodology and Technology for Power System Grounding

Grounding is the fundamental measures to ensure the safe
operation of power systems, including power apparatus and
control/monitoring systems, and guarantee the personal safety.
Grounding technology is an interdiscipline involving electrical
engineering, high voltage technology, electric safety,
electromagnetics, numerical analysis, and geological
exploration

Methodology and Technology for Power System
Grounding:

• Covers all topics related to power system grounding

• Presents fundaments and theories of grounding systems

• Well balances technology and methodology related to grounding
  system design

• Helps to understand the grounding analysis softwares

• Highlights the advanced research works in the field of
  grounding systems

• Comprehensively introduces numerical analysis methods

• Discovers impulse ionization phenomenon of soil around the
  grounding conductors

• Touches on lightning impulse characteristics of grounding
  devices for towers and buildings

As a comprehensive treatment of the topic, Methodology and
Technology for Power System Grounding is ideal for engineers
and researchers in power system, lightning protection, and
grounding. The book will also better equip postgraduates, senior
undergraduate students in electrical engineering.

Autorentext
Jinliang He is a Cheung Kong Chair Professor at Tsinghua University, the Chair of the university's High Voltage Research Institute, and the Chair of Power Transmission and Distribution Division of the State Key Lab of Power Systems. He is also the President of China Lightning Protection Standardization Committee and the President of High Voltage Technology Committee, Beijing Power Electrical Engineering Society.
His research interests mainly focuses on advanced power transmission technology in power systems. He has authored over 150 papers in international journals, more than 200 papers in national journals, and about 200 conference papers, and six books in Chinese. In 2008, Dr. He was awarded the National Invention Award. He obtained the honor of China National Outstanding Young Scientist Foundation in 2004. Due to his great contribution in lightning protection and grounding technology in power system, Dr. He was selected as a Fellow of IEEE in 2007. He received the Technical Achievement Award for significant contribution in his field from IEEE EMC Society in 2010. Currently he also serves as the Secretary of Standard Education and Training Committee of IEEE EMC Society. Dr. He is also a very active with the editorial boards of electrical engineering journals. Rong Zeng is a professor and Vice Dean of the Department of Electrical Engineering, Tsinghua University, where he received his B. Sc., M. Eng., and Ph. D. degrees in1995, July 1997, and July 1999 respectively.

Bo Zhang is an associate professor at the Department of Electrical Engineering, Tsinghua University. He received the B. Sc. and Ph. D. degrees in theoretical electrical engineering from the North China Electric Power University in 1998 and 2003 respectively.

Zusammenfassung

Grounding is the fundamental measures to ensure the safe operation of power systems, including power apparatus and control/monitoring systems, and guarantee the personal safety. Grounding technology is an interdiscipline involving electrical engineering, high voltage technology, electric safety, electromagnetics, numerical analysis, and geological exploration

Methodology and Technology for Power System Grounding*:*

• Covers all topics related to power system grounding
• Presents fundaments and theories of grounding systems
• Well balances technology and methodology related to grounding system design
• Helps to understand the grounding analysis softwares
• Highlights the advanced research works in the field of grounding systems
• Comprehensively introduces numerical analysis methods
• Discovers impulse ionization phenomenon of soil around the grounding conductors
• Touches on lightning impulse characteristics of grounding devices for towers and buildings
  As a comprehensive treatment of the topic, Methodology and Technology for Power System Grounding is ideal for engineers and researchers in power system, lightning protection, and grounding. The book will also better equip postgraduates, senior undergraduate students in electrical engineering.

Inhalt
Preface xiii Acknowledgements xv

1 Fundamental Concepts of Grounding 1

1.1 Conduction Mechanism of Soil 1

1.1.1 Soil Structure 1

1.1.2 Conduction Mechanism of Soil 1

1.2 Functions of Grounding Devices 2

1.2.1 Concept of Grounding 2

1.2.2 Classification of Grounding 3

1.2.3 Purpose of Grounding 5

1.3 Definition and Characteristics of Grounding Resistance 7

1.3.1 Definition of Grounding Resistance 7

1.3.2 Relationship between Grounding Resistance and Capacitance 8

1.3.3 Shielding Effect among Grounding Conductors 9

1.4 Grounding Resistance of Grounding Devices 11

1.4.1 Grounding Resistance of General Grounding Devices 11

1.4.2 Grounding Resistance of Grounding Device in Non-Homogeneous Soil 14

1.5 Body Safety and Permitted Potential Difference 19

1.5.1 Allowable Body Current Limit 19

1.5.2 Allowable Body Voltage 20

1.5.3 Allowable Potential Difference 21

1.5.4 Influence of Resistivity of Surface Soil Layer on Body Safety 23

1.6 Standards Related to Power System Grounding 25

References 26

2 Current Field in the Earth 27

2.1 Electrical Property of Soil 27

2.1.1 Soil Resistivity 27

2.1.2 Influence of Different Factors on Soil Resistivity 29

2.1.3 Permittivity of Soil 30

2.1.4 Frequency Characteristics of Soil Parameters 31

2.2 Basic Properties of a Constant Current Field in the Earth 36

2.2.1 Current Density in the Earth 36

2.2.2 Continuity of Earth Current Field 36

2.2.3 Potential of Stable Current Field 37

2.2.4 Current Field at the Interface of Layered Soil 37

2.3 Current Field Created by a Point Source in Uniform Soil 38

2.3.1 Laplace's Equation 38

2.3.2 Current Field Created by a Point Source in Soil 39

2.3.3 Earth Current Field Produced by Two Opposite Point Current Sources on the Ground Surface 41

2.3.4 Earth Current Field in Non-Uniform Soil 41

2.4 Potential Produced by a Point Source on the Ground Surface in Non-Uniform Soil 43

2.4.1 Horizontally Layered Soil 44

2.4.2 Horizontal Double-Layer Soil 45

2.4.3 Horizontal Triple-Layer Soil 46

2.4.4 Vertically Layered Soil 46

2.5 Potential Produced by a Point Source in Multi-Layered Soil 48

2.5.1 Analysis of Potential Produced by a Point Current Source 48

2.5.2 Numerical Integral Method to Calculate Green's Function of a Point Current Source 52

2.6 Computer Program Derivation Method of Green's Function 55

2.6.1 Method of Obtaining Analytic Expression 55

2.6.2 Expression of Green's Function Derived from Software Program 59

2.6.3 Calculation of Current Field in Multi-Layered Soil 62

2.7 Fast Calculation Method of Green's Function in Multi-Layered Soil 62

2.7.1 Development of a Two-Stage Fitting Method 63

2.7.2 Application of the Fast Calculation of Green's Function in Multi-Layered Soils 66

2.8 Current and Potential Distributions Produced by a DC Ground Electrode 69

2.8.1 Current and Potential Distributions of DC in Uniform Soil 69

2.8.2 Current and Potential Distributions of DC Current in Non-Uniform Soil 72

References 78

3 Measurement and Modeling of Soil Resistivity 81

3.1 Introduction to Soil Resistivity Measurement 81

3.2 Measurement Methods of Soil Resistivity 83

3.2.1 Sampling Analysis Method of Soil Resistivity 83

3.2.2 Electrical Sounding Methods 83

3.2.3 Test Probe Configuration for Four-Probe Method 88

3.2.4 Field Test Technique of Soil Resistivity 90…