Description
Book SynopsisThis book, along with its supporting animated website, helps the reader to understand the propagation of waves within complex intelligent structures within buildings, and the operation of systems designed to protect these structures. It also comments on proper human behaviour during a lightning thunderstorm.
Trade Review"…would be used by students or as a resource for those who need to design and specify electrical protection equipment…and by anyone with an interest in lighting." (
IEEE Electrical Insulation Magazine, March/April 2007)
Table of ContentsCHAPTERS and subsections Comment Page
PREFACE xi
INTRODUCTION 1
Guide to use the program 1
1. CLOUD, CYCLONE AND FRONTS 1-0 3
Development of a cloud 1-1 3
Growth of a thunderstorm cloud 1-5 4
Development of a cyclone 1-13 6
Warm and cold fronts 1-21 7
Distribution of thunderstorms 1-25 7
2. ELECTRIC CHARGES IN CLOUDS 2-0 9
Processes of charge separation 2-1 9
Charging process in the liquid phase 2-1 9
Charging process during freezing 2-8 10
Final distribution of charges 2-14 11
Static electric field 2-16 11
Relation to the ionosphere 2-17 12
3. DISCHARGE PROCESSES IN AIR 3-0 13
Photon processes 3-1 13
Excitation by photon 3-2 13
Ionisation and absorption 3-3 14
Recombination 3-4 14
Electron collisions 3-6 14
Excitation by electron 3-9 15
Ionisation by collision 3-10 15
Discharges 3-11 15
Electron avalanche 3-11 15
Streamer discharge 3-18 16
Klydonograph 3-22 17
Leader discharge 3-25 17
4. DEVELOPMENT OF THE LIGHTNING FLASH 4-0 19
Start on drops in the cloud 4-1 19
From leader to main stroke 4-5 20
Multiple stroke 4-13 21
CHAPTERS and subsections Comment Page
Upward leader 4-16 22
The Boys-camera: Principle and construction 4-22 23
The Boys-camera: Operation 4-27 24
Boys-record of ideal lightning 4-30 24
Real Boys-records 4-36 25
5. PHYSICS OF THE LIGHTNING DISCHARGE 5-0 27
Properties of a downward leader 5-1 27
Condition of connecting leader 5-5 28
Striking process 5-11 29
Development of main stroke 5-13 29
Multiple and upward stroke 5-15 30
The current wave 5-19 30
Lightning parameters 5-24 31
Distribution functions 5-28 32
6. CURIOUS LIGHTNING PHENOMENA 6-0 35
Properties of ball lightning 6-1 35
Ball lightning-theories 6-7 37
Resonance theory 6-10 37
Quantum-theory 6-11 38
Theory of magnetic vortex 6-12 38
Photos of ball lightning 6-18 39
Beaded lightning 6-23 40
Stroke from clear sky 6-28 41
Discharge to the ionosphere 6-31 41
7. INDUCED VOLTAGE 7-0 43
Ampère’s law 7-1 43
Rectangular loop + infinite conductor 7-5 44
Rectangular loop + cut conductor 7-8 44
Reduction to basic components 7-10 44
Triangular loop 7-13 45
Polygonal loop 7-16 45
Induced voltage due to direct stroke 7-18 46
Induced current due to direct stroke 7-23 46
Induced voltage due to distant stroke 7-28 47
Induced current due to distant stroke 7-35 48
8. DYNAMIC FORCES DUE TO LIGHTNING 8-0 51
Parallel wires 8-1 51
Force due to lightning on a rod struck at the top 8-8 52
Force due to lightning on a horizontal wire 8-12 53
Force due to lightning on a metal plate 8-15 53
Force of leaded current at inversion of wire 8-18 54
CHAPTERS and subsections Comment Page
Force of leaded current on a tube 8-20 54
Dynamic force on a console 8-22 54
Slit effect 8-27 55
Damage on tree 8-32 56
9. HEAT EFFECTS ON METAL OBJECTS 9-0 59
Heating a metal plate 9-1 59
Change of temperature in a metal plate 9-4 60
Equations of melting a metal plate 9-9 61
Crater and droplets 9-15 62
Melting a wire at contact spot 9-18 62
Melting a wire leading current 9-22 63
Probability of melting 9-30 64
10. LIGHTNING ATTACHMENT 10-0 67
Point of orientation 10-1 67
The striking distance 10-5 68
Distribution and density functions 10-7 68
The expected frequency of stroke 10-10 69
The principle of calculation 10-10 69
Collection space 10-17 70
11. COLLECTION SPACES OF STRUCTURES 11-0 73
The principle of collection space 11-1 73
Dividing the collection space 11-3 74
Two conductors 11-6 74
Lightning rod on tower 11-9 75
Air terminations of block-house 11-13 75
The collection space of one mesh 11-25 77
12. PROTECTIVE EFFECT ON FLAT ROOF 12-0 79
Air termination systems on blockhouse 12-1 79
Diagrams related to several air terminations 12-4 80
Application of rolling sphere method 12-8 81
13. PROTECTION OF INCLINED ROOF 13-0 83
Types of air termination systems 13-1 83
Attraction of roof and eaves 13-6 84
Effect of electrodes on eaves 13-11 85
Effect of electrodes on the edges 13-15 85
Attraction of unprotected edges 13-23 87
Stroke-free period 13-26 87
14. RESIDUAL RISK OF LIGHTNING PROTECTION 14-0 89
The flow diagram 14-1 89
Equivalent area of a structure 14-2 89
Cases of the point of strike 14-11 91
Cases of damaging stroke 14-18 92
Intercepted stroke 14-19 92
CHAPTERS and subsections Comment Page
Striking the roof 14-23 93
Calculation of risk 14-27 94
Weighting the consequences 14-28 95
Resulting damage 14-38 97
Resulting frequency of weighted damage 14-40 97
Resulting risk 14-44 98
15. CLASSIFICATION OF STRUCTURES 15-0 101
Classes of structures 15-1 101
Height and surroundings 15-12 103
High surroundings 15-13 103
Increased danger of stroke 15-18 104
Classes according to height 15-26 106
Effect of the soil profile 15-27 106
The materials of roof 15-31 107
Further classifications 15-37 108
16. AIR TERMINATION SYSTEMS 16-0 111
Level of risk and protection 16-1 111
Construction methods 16-3 111
Protective angle 16-3 111
Rolling sphere 16-7 112
Mesh size 16-9 112
Degrees of Hungarian standard 16-12 113
Natural air termination 16-13 113
Simplified air termination 16-17 114
Data of higher degrees 16-19 114
Distance to the structure 16-21 115
Forms of air terminations 16-28 116
17. DOWN CONDUCTORS AND METAL OBJECTS 17-0 119
Down conductors 17-1 119
Calculation of current paths 17-1 119
Example of current path 17-9 120
Positioning along the perimeter 17-15 121
Degrees of down conductors 17-17 121
Forms of down conductors 17-22 122
Vertical metal structures 17-26 123
Dangerous loops 17-26 123
Bonding metal structures 17-30 124
Insulating spacers 17-34 124
Elevators 17-37 125
18. EARTHING OF LIGHTNING PROTECTION SYSTEM 18-0 127
Degrees of earthing 18-1 127
Natural earthing 18-2 127
Simple earthing systems 18-5 128
CHAPTERS and subsections Comment Page
Earthing resistance 18-10 129
Normal and enhanced systems 18-17 130
Earthing by foundation 18-22 131
Soil resistivity 18-27 132
Measurement of earthing resistance 18-30 132
Impulse earthing 18-32 132
19. LIGHTNING ELECTROMAGNETIC IMPULSE 19-0 135
Conductive coupling 19-1 135
Inductive coupling 19-3 136
Capacitive coupling 19-5 136
Distribution of current 19-7 136
Arriving current along a single line 19-10 137
Arriving current along branching line 19-15 138
Faraday holes 19-20 139
Shielded entrance 19-25 139
Shielded cable 19-30 140
Circuit of lightning 19-32 141
20. GRADED SURGE-PROTECTION 20-0 143
Operation principles 20-1 143
Three stage with resistors 20-6 144
Influence of distance between stages 20-11 145
Propagation of waves 20-19 146
Waves on devices 20-27 147
21. SURGE PROTECTION DEVICES 21-0 149
Gas filled arrester 21-1 149
Arc blowing spark gap 21-5 150
Gliding spark gap 21-9 150
Encapsulated arrester 21-13 151
Characteristics of gaps 21-18 152
The varistor 21-20 152
Characteristics of varistor 21-29 153
Types of protection devices 21-33 154
22. INTERNAL LIGHTNING PROTECTION ZONES 22-0 157
Structure of zones 22-1 157
Standardised lightning parameters 22-5 158
Networks of information systems 22-6 158
Tray configuration 22-17 160
23. CONNECTION TO ELECTRIC POWER NETWORK 23-0 161
Striking the supply line 23-1 161
Striking the air termination 23-10 162
TT system 23-17 163
Outdoor kWh box 23-22 164
CHAPTERS and subsections Comment Page
24. PROTECTION OF ELECTRONIC DEVICES 24-0 167
Protection of personal computer 24-1 167
Protection of television 24-10 169
Relay station 24-16 170
25. LIGHTNING MEASUREMENT AND LOCALIZATION 25-0 171
Measuring of lightning current 25-1 171
Magnetic card 25-2 171
Magnetic link 25-5 172
Shunt resistor 25-9 172
Coil of Rogowski 25-13 173
Reflection of the current wave 25-18 174
Localising by direction finding 25-21 174
Localising by pulse arrival time 25-24 175
Lightning detection systems 25-28 175
26. THE MANKIND IN THE THUNDERSTORM 26-0 177
Danger in open air 26-1 177
Danger on or beside a tree 26-5 178
Step voltage 26-11 179
What to do outdoors? 26-14 179
Danger on a bicycle 26-18 180
Danger at a car 26-22 180
Danger at a truck 26-26 181
Danger in water 26-30 182
Danger in boats and vessels 26-34 182
REFERENCES 185
INDEX 189
