Overhead Electric Power Lines: Theory and practice

Contents
About the authors
Preface
Acknowledgements
1. Introduction
	1.1 Focus
	1.2 Overhead lines
	1.3 Voltage level
	1.4 Safety measure
	1.5 Chapters at a glance
2. Transmission line fundamentals
	2.1 Introduction
	2.2 Classification of lines
	2.3 Line parameters
	2.4 Resistance
	2.5 Inductance
	2.6 Skin effect
	2.7 Proximity effect
	2.8 Method of determination of effective resistance
	2.9 Capacitance
	2.10 Sequence impedance
	2.11 Short transmission line
	2.12 Medium transmission line
	2.13 Long transmission line
	2.14 Comparison with AC overhead lines
	2.15 Efficiency
	2.16 Regulation
	2.17 Major sinks of reactive power
	2.18 Major sources of reactive power
	2.19 Voltage control centres
	2.20 Major voltage control techniques or equipment
	2.21 Excitation system at generating station
	2.22 Tap changing transformer
	2.23 Synchronous machine
	2.24 I–V Characteristics without voltage control
	2.25 I–V Characteristics with ideal voltage control
	2.26 P–V Characteristics
	2.27 Voltage, power and impedance
	2.28 Synchronous condenser
	2.29 Voltage collapse
	2.30 Voltage stability
	2.31 Factors of power transmission capacity
	2.32 Flexible AC transmission system
	2.33 Static phase shifter
	2.34 FACTS and solar–wind hybrid grid
	2.35 Line capability
	2.36 Summary
	Further reading
3. Line support, foundation and mechanical sag
	3.1 Introduction
	3.2 Components of overhead lines
	3.3 Design aspects of distribution system
	3.4 Design aspects in transmission system
	3.5 Foundation
	3.6 Mechanical sag and tension
	3.7 Stringing
	3.8 Summary
	Further reading
4. Corona
	4.1 Introduction
	4.2 What is corona?
	4.3 Voltage in a single-phase two-wire transmission line
	4.4 Electric stress in a single-phase two-wire transmission line
	4.5 Power loss
	4.6 Factors of corona
	4.7 Methods of reducing corona
	4.8 Corona ring
	4.9 Disadvantages
	4.10 Advantages of corona
	4.11 Corona in HVDC lines
	4.12 Research advancement
	4.13 Summary
	4.14 Standard
	References
5. Overhead line insulator
	5.1 Introduction
	5.2 Overhead line insulator
	5.3 Common properties of line insulator
	5.4 Material of overhead line insulators
	5.5 Classification of overhead line insulators
	5.6 Requirement of insulator sets
	5.7 String of insulators
	5.8 Voltage distribution in string
	5.9 Effect of unequal voltage distribution
	5.10 String efficiency
	5.11 Improvement of voltage distribution and string efficiency
	5.12 Selection practice for insulator
	5.13 Associated design factors of insulators
	5.14 Clamps
	5.15 Nuts and bolts
	5.16 Failure of insulator
	5.17 Standards, test and practice
	5.18 Summary
	5.19 Useful standards and guidelines for further study
	References
6. Conductor
	6.1 Introduction
	6.2 Conductor property
	6.3 Materials
	6.4 Conductor types
	6.5 Hollow conductor
	6.6 Conductor with optical fibre cable
	6.7 Phase conductors
	6.8 Earth wire or sky wire
	6.9 Jumper
	6.10 Covered conductors or overhead cables
	6.11 Current load
	6.12 Conductor fittings
	6.13 Common stringing method
	6.14 Tension methods
	6.15 Design features
	6.16 Conductor temperature
	6.17 Conductor vibration
	6.18 Conductor damages
	6.19 Summary
	6.20 Standards
	References
7. Earthing and earth wire
	7.1 Introduction
	7.2 Electric current on body
	7.3 Soil resistivity
	7.4 Electrode
	7.5 Earthing mat or earthing grid
	7.6 Earthing conductor or earthing wire
	7.7 Materials used for earthing
	7.8 Touch potential
	7.9 Step potential
	7.10 Voltage gradient
	7.11 Soil resistance and its measurement
	7.12 Soil resistance measurement
	7.13 Earth resistance of electrode and its measurement
	7.14 Radial or star connection of electrodes
	7.15 Limitation of isolated neutral or ungrounded system
	7.16 Neutral grounded system
	7.17 Different grounding methods
	7.18 Resonant grounding or Peterson coil grounding
	7.19 Fault current at different earthing system
	7.20 Harmonic suppression system
	7.21 Earthing transformer
	7.22 Grounding practice
	7.23 Earthing for personal safety
	7.24 Earth wire
	7.25 Design features of earth wire
	7.26 Earth wire selection
	7.27 Optical ground wire fibre reinforced
	7.28 Earthing of tower
	7.29 Grounding in pole support
	7.30 Earthing of guard wire insulators’ support end
	7.31 Neutral grounding in LV distribution line
	7.32 Research advancement
	7.33 Summary
	7.34 Standards and guidelines
	References
8. Lightning and surge protection
	8.1 Introduction
	8.2 Lightning strokes
	8.3 Formation
	8.4 Characteristics
	8.5 Return lightning discharge or return stroke
	8.6 Multiple strokes
	8.7 Frequency and intensity
	8.8 Effect of lightning and protective measures
	8.9 Earthing
	8.10 Earth wire or sky wire
	8.11 Shielding by earth wire
	8.12 Surge impedance of earth wire
	8.13 Other overvoltages
	8.14 Line faults
	8.15 Wave propagation in transmission line
	8.16 Surge arresters
	8.17 Surge absorber
	8.18 Overvoltage measurement
	8.19 Measurement of dissipation factor
	8.20 Measurement of partial discharge
	8.21 High-voltage testing
	8.22 Summary
	8.23 Standards or guidelines
	References
9. Insulation coordination
	9.1 Introduction
	9.2 Voltage factors insulation selection
	9.3 Voltage signals in overhead lines
	9.4 Insulation coordination for a line insulator
	9.5 Basic impulse insulation level
	9.6 Insulation coordination with lightning arrester
	9.7 Substation considerations
	9.8 Common consideration for insulation coordination
	9.9 Contamination
	9.10 Summary
	9.11 Standards
	References
10. Route selection, commissioning, operation and maintenance
	10.1 Introduction
	10.2 Route selection
	10.3 Planning and construction
	10.4 Commissioning
	10.5 Operation and maintenance
	10.6 Post-commissioning planning and management
	10.7 Research direction
	10.8 Summary
	References
	Further reading
Index