vii
TABLE OF CONTENTS
CHAPTER
1
2
TITLE
PAGE
DECLARATION
ii
DEDICATION
iii
ACKNOWLEDGEMENTS
iv
ABSTRACT
v
ABSTRAK
vi
TABLE OF CONTENTS
vii
LIST OF TABLES
x
LIST OF FIGURES
xi
LIST OF ABBREVIATIONS
xiv
LIST OF SYMBOLS
xv
LIST OF APPENDICES
xvii
INTRODUCTION
1
1.1
Introduction
1
1.2
Problem Statement
2
1.3
Objective
4
1.4
Scope of Project
5
1.5
Organization of Thesis
5
LITERATURE REVIEW
6
2.1
Lightning Problem for Transmission Line
6
2.2
Effects on Transmission Line Protection
7
2.2.1
7
2.3
Backflashover
Travelling Wave
viii
2.4
Lightning Current
8
2.4.1
9
Characterization of the lightning discharge
2.5
Line Insulation Flashovers Model
11
2.6
Ground Flash Density
16
2.7
Tower Footing Resistance
16
2.8
Transmission Line Tower
17
2.8.1
Development of Tower Model
17
2.8.2
Tower model
18
2.9
Surge arrester
21
2.10
Transmission Line Model
24
2.11
Monte Carlo Simulation
25
2.11.1 The 3-Dimensional Electrogeometric Model
26
2.11.2 3-Dimensional Simulation of Fields of Influence
26
2.11.3 3-Dimensional Modeling of The Lightning Stroke 27
3
2.11.4 Ground Flash Density
30
2.11.5 Shielding Effect of a Vertical Rod
30
METHODOLOGY
31
3.1
ATP-EMTP Simulation
31
3.2
Typical EMTP Applications
32
3.3
Creating Simulation File
33
3.4
Creating Punch File
35
3.5
Simulation
36
3.6
Plot File
37
3.7
Transmission line
37
3.8
Transmission tower
38
3.9
Insulator String
44
3.10
Lightning source selection
44
3.11
Monte Carlo Simulation
47
3.12
Project Flow
50
ix
4
SIMULATION RESULT AND DISCUSSION
53
4.1
Introduction
53
4.2
Line Surge Arrester Study
54
4.2.1
Transmission tower
54
4.2.2
Transmission Line and Tower Circuit Model on
55
EMTP Simulation
4.3
5
Lightning Protection of Structures
64
4.3.1
64
Simple Structure Protection Result
CONCLUSIONS AND RECOMMENDATIONS
74
5.1
Conclusions
73
5.2
Recommendations
75
REFERENCES
76
Appendix A
80
x
LIST OF TABLES
TABLE NO.
TITLE
PAGE
2.1
Flashover rate for different circuit without line surge arrester
23
2.2
Flashover rate for different circuit with line surge arrester
23
3.1
Parameter of the 275/132kV quadruple tower model
42
4.1
Voltage between each phase and insulator string at tower 3
63
4.2
Voltage between each phase and insulator string at tower 4
63
4.3
Lightning stroke with effective striking distance
71
xi
LIST OF FIGURES
FIGURE NO.
1.1
TITLE
Transmission line had caused the breakage of the conductor
PAGE
3
at four portions
1.2
The direct stroke on shield wire between T70-T71 affected
3
Three TLAs installed at T69 and T68
2.1
Reflection and refraction at tower after lightning strike
8
2.2
Lightning current shape, according to IEEE guidelines
10
2.3
Peak current magnitude (kA) versus flashover rate
10
2.4
Rise time lightning current versus flashover rate
11
2.5
Critical flashover voltage for 275/132kV transmission line
12
2.6
The back flashover mechanism.
14
2.7
Model used for string of insulator up 275/132kV.
14
2.8
Kawai tower model
18
2.9
Mathematical calculation for multistory tower model
20
2.10
Multiconductor vertical line model
20
2.11
Line arrester installed on 275/132kV
22
2.12
Transmission line model
23
2.13
Fields of influence of a vertical rod and ground. Rs and rsg
28
are the effective striking distances of the vertical rod and ground
2.14
Fields of influence of horizontal wire and ground
28
2.15
Fields of influence of rectangular block and ground
29
2.16
Display of lightning strokes (represented by dots) terminating
30
on structure (vertical rod) and surrounding ground - plan view
xii
3.1
Overview of ATPDraw commands and function
32
3.2
Data window for simulation setting
34
3.3
Data window for inserting the parameter
35
3.4
Data window for transmission line
36
3.5
Transmission line model
39
3.6
Multistorey transmission tower
39
3.7
M.Ishii’s tower model for a double line tower
40
3.8
Tower equivalent radius
41
3.9
Modified M.Ishii’s tower model for a quadruple circuit line
43
tower modeling
3.10
Insulation string model
44
3.11
Waveform of fast front voltage surge using Heidler model,
45
20kV with 0.5µs fast front time
3.12
Waveform of voltage using DC model, 20kV with 0.5µs fast
46
front time
3.13
Voltage at tower top by using a DC source as input
47
3.14
Flow chart of Monte Carlo simulation on transmission line
49
3.15
Project flow chart
51
3.16
Protection of simple structures due to lightning strikes
52
4.1
Complete multistorey model
54
4.2
Voltage at tower top, tower base and each crossarm of the tower
55
4.3
The simulation circuit of 275/132kV multistory quadruple
56
transmission line, transmission tower with EMTP
4.4
Voltage at red phase and insulator string tower 3 (275kV)
57
4.5
Voltage at blue phase and insulator string tower 3 (275kV)
57
4.6
Voltage at yellow phase and insulator string tower 3 (275kV)
58
4.7
Voltage at red phase and insulator string tower 3 (132kV)
58
4.8
Voltage at blue phase and insulator string tower 3(132kV)
59
4.9
Voltage at yellow phase and insulator string tower 3(132kV)
59
4.10
Voltage at red phase and insulator string tower 4 (275kV)
60
4.11
Voltage at blue phase and insulator string tower 4 (275kV)
60
xiii
4.12
Voltage at yellow phase and insulator string tower 4 (275kV)
61
4.13
Voltage at red phase and insulator string tower 4 (132kV)
61
4.14
Voltage at blue phase and insulator string tower 4 (132kV)
62
4.15
Voltage at yellow phase and insulator string tower 4 (132kV)
62
4.16
Lightning Surge Arrester Configuration L-Arrangement
64
4.17
Display of lighting strokes at surrounding ground-plan view
65
4.18
Display of lightning strokes (represented by dots)
66
terminating on structure (vertical rod), and surrounding
ground-plan view with current 2.5kA and 5kA.
4.19
Vertical rod and its effective striking with current 2.5kA
69
4.20
Vertical rod and its effective striking with current 5kA
69
4.21
Vertical rod and its effective striking with current 10kA
70
4.22
Vertical rod and its effective striking with current 15kA
70
4.23
Field of influence of a rectangular block above ground which
72
can be used to represent a building structure or a patch of trees
with current 2.5kA with 2 dimensional electrogeomatric model.
4.24
Field of influence of vertical cylinder can be used to represent a
building structure or a patch of trees with current 2.5kA
(3 dimensional electrogeomatric model).
72
xiv
LIST OF ABBREVIATIONS
ATP
-
Alternative Transient Program
EMTP
-
Electromagnetic Transient Program
TLA
-
Transmission Line Arrester
TD
-
Thunder Days
CIGRE
-
International Conference on Large High-Voltage Electric
System
IEEE
-
Institute Electrical and Electronics Engineers
LCC
-
Line Cable Constant
R-L
-
Resistance and Inductance
SiC
-
Silicon Carbide
DC
-
Direct Current
xv
LIST OF SYMBOLS
V
-
Voltage
θ
-
Angle
Ω
-
Ohm
I
-
Current
kV
-
Kilo-Volt
m/µs -
Meter per Micro-second
R
-
Resistance
L
-
Inductance
C
-
Capacitance
µs
-
Micro-second
kA
-
Kilo-Ampere
mH
-
Millie-Henry
µF
-
Micro-Farad
t
-
Time
%
-
Percent
-
Tower surge impedance
-
Attenuation coefficient
-
Damping coefficient
-
Height
-
Probability current
H
xvi
Ng
-
Field of influenced of object
-
Number of flashes to ground per square kilometer per year
xvii
LIST OF APPENDICES
APPENDIX
A
TITLE
1)
275/132kV Transmission line and
PAGE
81
Transmission Tower Model - EMTP
2)
Matlab Simulation of lightning strokes
81
(represented by dots) terminating on
Structure (vertical rod), and surrounding
ground-plan view with current
3)
Matlab Simulation of lightning strokes
84
(represented by dots) terminating on
structure (vertical rod
4)
Matlab Simulation of field of influence of
vertical cylinder can be used to represent
a building structure
88