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MODELLING SINGLE GROUNDING ELECTRODE USING COMSOL
ABDULMANAN MEMON
A project report submitted in fulfilment of the
Requirements for the award of the degree of
Master of Engineering (Electrical Power)
Faculty of Electrical Engineering
Universiti Teknologi Malaysia
JUNE 2015
iii
DEDICATION
To My Parents
iv
ACKNOWLEDGEMENT
I would like to thank and express my sincere appreciation to my supervisor,
Dr. MUHAMMAD ABU BAKAR SIDIK who gave so generously of his time and
energy in coaching, guiding and assisting me in completing my master project.
Without his help and support I would have never been able to complete my master
project. He always inspired me and at times provided me with great ideas as well.
A special thanks to my father, Nazir Ahmad whose endless prayers, support
and guidance helped me in achieving this goal. I also want to express my sincerest
thanks to my beloved mother and Grandmother Farida Memon and Zeenat for
everything they did for me.
Lastly, I would like to express my gratitude to my siblings, other family
members and friends for their help, love and support. Thank you.
v
ABSTRACT
In electrical engineering, the necessity of grounding system refers to a system
where conductor is grounded and intended or may cause the current to flow under
normal operations. Grounding system is designed for appropriate of the clearing the
grounding faults and dissipates the lightning energy. Most commonly used material
for the grounding system is copper. However the increasing price and theft issue of
copper has led to research materials other than copper with additive filler to
overcome problem as well as maintaining the efficiency of an electrical system. The
current project analyses the mixture of copper and graphite along with silica glass
and amorphous carbon used as an additive material for the analysis of the system.
The analysis was done using COMSOL multi-physics software. The voltage
distribution and current density was analysed which showed that graphite rod can be
used instead of copper.
vi
ABSTRAK
Dalam bidang kejuruteraan elektrik, keperluan sistem pembumian merujuk
kepada satu sistem di mana konduktor dibumikan dan bertujuan atau boleh
menyebabkan arus mengalir di bawah operasi normal. Sistem pembumian direka
untuk sesuai bagi penjelasan kesalahan asas dan membebaskan tenaga kilat. Bahan
yang paling biasa digunakan untuk sistem pembumian adalah tembaga. Walau
bagaimanapun harga dan isu kecurian tembaga yang semakin meningkat telah
membawa kepada penyelidikan bahan-bahan lain daripada tembaga dengan bahan
tambahan lain untuk mengatasi masalah serta mengekalkan kecekapan sistem
elektrik. Jika dilihat projek semasa di mana mereka menganalisis campuran tembaga
dan grafit bersama-sama dengan kaca silika dan karbon amorfus yang digunakan
sebagai bahan tambahan untuk menganalisis sesuatu sistem. Bagi projek ini, analisis
dijalankan menggunakan COMSOL perisian multi-fizik. Pengagihan voltan dan
ketumpatan arus dianalisis yang menunjukkan bahawa batang grafit boleh digunakan
selain daripada tembaga.
.
vii
TABLE OF CONTENTS
CHAPTER TITLE PAGE
DECLARATION ii
DEDICATION iii
ACKNOWLEDGEMENT iv
ABSTRACT v
ABSTRAK vi
TABLE OF CONTENTS vii
LIST OF TABLES x
LIST OF FIGURES xi
LIST OF ABBREVIATIONS xiii
LIST OF SYMBOLS xv
LIST OF APPENDICES xvii
1 INTRODUCTION 1
1.1 Introduction 1
1.2 Grounding System 2
1.3 Problem Statement 3
1.4 Objectives of the Project 3
1.5 Scope of Project 3
1.6 Report Outline 4
2 LITERATURE REVIEW 5
2.1 Introduction 5
2.2 Earth Enhancement Compound and Materials 6
2.3 Grounding 6
2.4 Soil characteristics 7
viii
2.4.1 Soil as grounding medium 7
2.4.2 Effect of voltage gradient 7
2.4.3 Effect of current magnitude 8
2.4.4 Effect of moisture, temperature, and chemical
content 8
2.5 Grounding Resistance of Grounding Electrode using
Corban Plate Made of Woody Materials 9
2.6 Bentonite with Natural Materials like Coconut Coir peat
Paddy Dust 9
2.7 Artificial treatment for the Reduction of Resistance in
Ground Electrode 10
2.8 Grounding Electrode Copper and Galvanized Iron with and
without earth additive filler 10
2.9 Decreasing Ground Resistance of Substation by Deep-
Ground Well Method 11
2.10 Improvement of Electrical Properties of Grounding loop by
Using bentonite and waste drilling mud 11
2.11 Nessacary Conditions for the Backfill Materials used for
Grounding Resistance of Grounding Loop Reduction 12
2.12 Portable and Compact Grounding System with Copper
Plates 13
2.13 Imperfect contacts between between grounding electrode
and soil on electrical properties of grounding Loop 14
2.14 Backfill Composition Anode bed and Apparatus 14
2.15 Electrical Conductive Cement Based Materials 15
3 METHODOLOGY 17
3.1 Introduction 17
3.2 Grounding Rod Design 18
3.3 SOIL Design 18
3.4 COMSOL MULTIPHYSCIS 20
3.5 COMSOL DESKTOP ENVIORMENT 23
3.6 The COMSOL MODULES 24
3.7 AC/DC MODULE 24
ix
3.7.1 ELECTRIC CURRENT 25
3.7.2 ELECTRIC CURRENT SHELLS 25
3.7.3 ELECTRIC CIRCUIT 25
3.7.4 ELECTROSTATIC 26
3.8 METHODOLOGY /FLOW CHART 26
3.9 How to Create a New Model in COMSOL 27
3.10 COMSOL MULTIPHYSCIS REQUIRED PARAMETER 27
4 RESULTS AND DISCUSSION 35
4.1 Introduction 35
4.2 Result Analysis 35
4.2.1 Grounding Rod (Copper) without Additive 35
4.2.2 Grounding Rod (Graphite) without additive 38
4.2.3 Grounding Rod with Additive 39
5 CONCLUSION AND FUTURE WORK 44
5.1 Conclusion 44
5.2 RECOMMENDATION FOR FUTURE WORK 45
REFERENCES 46
Appendices A 48
x
LIST OF TABLES
TABLE NO. TITLE PAGE
3.1
Resistivity value for several types of soils and water
20
xi
LIST OF FIGURES
FIGURE NO. TITLE PAGE
2.1
2.2
3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8
3.9
3.10
3.11
3.12
3.13
3.14
3.15
3.16
4.1
4.2
4.3
4.4
4.5
4.6
Earth Model in Resistance form
Resistivity Curve with Salt Moisture and Temperature
Variation
Curve between resistance and temperature
COMSOL MODULEs.
Electromagnetic Module of COMSOL.
GUI of COMSOL Module
Model Selection Selection.
Dimension Selection Window of COMSOL
Module Selection Window of COMSOL.
Variable Selection/Physics Selection
Model Setting Windows.
Rod Design
Additive Design
Soil Design
Material Selection
Voltage Selection.
Ground Selection
Geometry Meshing .
Grounding Rod without additive
Cutline selection
Cutline points selection
Current density with copper without additive
Voltage distribution with copper without additive
Voltage distribution with graphite without additive
7
8
19
21
22
23
28
28
29
30
30
31
31
32
32
33
33
34
36
36
37
37
38
38
xii
4.7
4.8
4.9
4.10
4.11
4.12
4.13
4.14
Current density with graphite without additive
Simulation of Grounding rod with copper and glass as
additive
Voltage Distribution with Copper and silica as additive
Material.
Current Density with copper and silica as Additive.
Voltage Distribution with Copper and Corban (amorphous)
as Additive.
Current density with Copper and Corban Amorphous as
additive Material.
Voltage Distribution with graphite and Corban (amorphous)
as Additive.
Current Density with graphite and Corban (amorphous) as
Additive
39
40
40
41
41
42
42
43
xiii
LIST OF ABBREVIATIONS
EPN
AC
GEM
GAM
HCBM
ZP
SV
ECH
FC
VS
GA
VD
CD
SG
CA
NES
EAM
VG
AT
LPS
EMI
CM
SD
PDE
CDE
ECS
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Electrical Power Network
Alternating Current
Ground Enhancing Material
Ground Additive Material
High Conductivity Backfill Material
Zero Potential
Stray Voltage
Electric Shock Hazard
Fault Condition
Voltage Stabilization
Grounding Agent
Voltage Distribution
Current Density
Silica Glass
Corban Amorphous
National Electrical Safety
Earth Enhancing Material
Voltage Gradient
Artificial Treatment
Lightning Protection System
Electromagnetic Interference
COMSOL Multiphyscis
Soil Design
Partial Differential Equation
COMSOL Desktop Environment
Electric Current shells
xiv
ES
MSM
MW
RF
EF
SEP
-
-
-
-
-
-
Electrostatic
Material Selection Modules
Model Wizard
Radio Frequency
Electric Filed
Scalar Electric Potential
xv
LIST OF SYMBOLS
Dh
De
nm
°C
Tm
Tg
BO3
BO4
n
a
Z
Eg
To
Tm
E
m
s
b
eV
k
A
μg
β
min
P
f(D)
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Demarcation for Holes
Demarcation for Electrons
Nanometer
Celsius
Melting Temperature
Transition Temperature
Triangular Units
Tetrahedral Unit
Refractive Index
absorption coefficient
Atomic Number
Energy Band Gap
Irradiation Temperature
Maximum Peak Temperature
Trap Depth or Activation Energy
Concentration of Holes
Frequency Factor
Kinetics Order
Electron Volt
Boltzmann Constant
Area Under Glow Curve
Geometric Factor
Linear Heating Rate
Minute
Transition Probability
Linearity Index
xvi
σB
F
B*
Zeff
S(E)
(μen/ρ)
Gy
ρ
Vm
M
NA
XB
N
rp
ri
Å
Tc
cm
Mv
MeV
Trg
HR
fexp
[OV]
h
nC
w
σT/D
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Standard Deviation of Background
Conversion Factor
Background Signal
Effective Atomic Number
Energy Response
Mass Energy Absorption Coefficient
Gray
Density
Molar Volume
Molecular Weight
Avogadro’s Number
Mole Fraction
Ion Concentration
Polaron Radius
Inter-nuclear distance
Angstrom
Crystalline Temperature
Centimeter
Megavolt
Mega Electron Volt
Glass Forming Ability
Glass Stability
Oscillator Strength
Oxygen Vacancy
Hole
Nanocolumbs
Fractional Weight
Relative Total Standard Deviation
xvii
LIST OF APPENDICES
APPENDIX TITLE PAGE
A Resistivity and conductivity values 48
CHAPTER 1
INTRODUCTION
1.1 Introduction
Grounding basically originally began as the safety measure to help prevent
people from accidently coming in contact with electrical Hazards. In the electrical
system the grounding system or earthing system are the circuits used to connect
electrical devices to the ground. Grounding of electrical installation is primarily
concerned when safety aspect of equipment and user are concern. In the electrical
system grounding is important provide a reference voltage (zero potential ground
potential) against which all other voltages in a system are established and measured.
An effective ground connection also minimize the susceptibility of equipment to
interface reduce the risk of equipment damage due to lightning.
In electrical power network grounding system help to maintain the voltage of
any part of electrical network within a predetermined range of with respect to earth
under safety and fault condition. Electrical ground system have an appropriate
current carrying capabilities. Ground also consider as idealized as infinite source or
sink for charge which can absorb unlimited amount of current without changing its
potential. For the real grounding connection has significant resistance the
approximation voltage is no longer valid stray voltage and earth potential rise occurs
which may create the noise in signal if large noise produce that cause the electric
shock hazard.
2
If grounding system installed correctly it should allow the enough current to
flow under fault condition. To operate the protective device installed correctly the
rise in potential during fault condition combined with fault clearance should be
minimize the both risk of electrocution to individual near the site of damage to
equipment. Widespread usage of electrical appliance used in industries as well as
used in homes also introduces many situation where efficient grounding is paramount
importance especially to prevent from electrical shock under fault condition.
1.2 Grounding System
The necessity of grounding system is refers to a system where conductor is
grounded and intended or may cause to current flow in normal operation. Grounding
system is very important. It is not only expensive to build an appropriate ground
system during initial construction of any electrical system but it can also expensive to
add it enhance it or replace it. After the completion of the electrical network, for the
design of grounding system point taken in to consideration for the appropriate of
clearing ground faults and dissipating lighting energy.
In term of grounding and earthing most of the people can quite confused.
Earthing is common word used in outside in United States of America. Earthing is
the connection of the equipment and facilities to mother Earth and in the lighting
protection system the earthing terminal is the point where lighting current discharge
to earth. The word grounding is used in the northern America both word has nearly
same meaning but difference is that different term used by different countries.
As discussed there are several important reasons why grounding system should be
installed. The most important reason is to protect people other to protection of
electrical device from unintentional contact with energized electrical lines.
Grounding system provide the maximum electrical safety from the electrical system
faults and lighting.
A good grounding system should have periodic inspection and maintenance
program to ensure its effectiveness continued. The periodic maintenance is added
3
through adequate design choice of material (for the electrodes) and proper
installation techniques to ensure that the grounding system resist deterioration or
inadvertent destruction the performance of such electrode depend on the soil type
composition conductivity moisture content soil temperature and etc.
1.3 Problem Statement
The mostly using material for grounding system is copper but due to
increasing price and theft problem of copper it is important to analyse the different
material other than copper with additive grounding material also be analysed. To
overcome the problem of cost as well as theft issues, reduce the cost of system,
reduce the losses and increase the efficiency of an electrical system.
1.4 Objectives of the Project
The objective of this research is as follows:
i) To review and investigate grounding- agent’s performance.
ii) To simulate and analyze the different behaviors of the several
grounding rod material mixed with grounding agent materials
1.5 Scope of Project
This project will cover the work on the analysing the grounding rod
materials. Study of the replacement of copper graphite, and the usage of additive
grounding material for the decreasing the grounding resistance and corrosion
reduction. As for the methodology concern the simulation will be performed on by
using COMSOL Software.
4
1.6 Report Outline
This report is composed of five chapters. The first chapter discusses the
background of this research, problem statement, objective and Scope. Chapter 2
contains the literature review of the grounding materials used for the grounding
system design. Chapter 3 describe the methodology how to use the Comsol
Multiphyscis 4.4 for the grounding system. Chapter 4 will present the results and
discussion about the grounding system in electrical terms. The problem and
challenges faced during simulation and design also discussed in this chapter. Chapter
5 discussed the conclusion of the whole project and some recommendation of
improvement is presented.
REFERENCES
1. Weinberg, D.I., Grounding for electrical safety. Medical and Biological
Engineering and Computing, 1964. 2(4): p. 435-437.
2. Mahtar, F., et al. Comparison study of usage as grounding electrode between
galvanized iron and copper with and without earth additive filler. in Applied
Electromagnetics, 2007. APACE 2007. Asia-Pacific Conference on. 2007.
IEEE.
3. Androvitsaneas, V., I. Gonos, and I. Stathopulos. Performance of ground
enhancing compounds during the year. in Lightning Protection (ICLP), 2012
International Conference on. 2012. IEEE.
4. Solon, O., REQUIREMENTS FOR EARTHING ENHANCEMENT
COMPOUNDS.
5. Sverak, T.G. and D.N. Laird. IEEE Guide for Safety in AC Substation
Grounding. 1986. The Institute of Electrical and Electronics Engineers.
6. Shimizu, H. and N. Watanabe. Grounding resistance of grounding electrode
using carbon plate made of woody material. in Lightning Protection (ICLP),
2012 International Conference on. 2012. IEEE.
7. Martínez, H.E., et al., A new artificial treatment for the reduction of resistance
in ground electrode. Power Delivery, IEEE Transactions on, 2004. 19(2): p.
601-608.
8. He, J., et al., Decreasing grounding resistance of substation by deep-ground-
well method. Power Delivery, IEEE Transactions on, 2005. 20(2): p. 738-744.
9. Kostic, M., et al., Improvement of electrical properties of grounding loops by
using bentonite and waste drilling mud. IEE Proceedings-Generation,
Transmission and Distribution, 1999. 146(1): p. 1-6.
10. Trifunović, J., The algorithm for determination of necessary characteristics of
backfill materials used for grounding resistances of grounding loops reduction.
Journal of Electrical Engineering, 2012. 63(6): p. 373-379.
47
11. Hassan, W., M. Akmal, and M. Kamran. Portable and compact grounding
system. in Power Engineering Conference (UPEC), 2013 48th International
Universities'. 2013. IEEE.
12. Trifunovic, J. and M. Kostic, Analysis of influence of imperfect contact
between grounding electrodes and surrounding soil on electrical properties of
grounding loops. Electrical Engineering, 2013: p. 1-11.
13. Tatum Jr, J.F., Ground electrode backfill composition, anode bed and
apparatus. 1988, Google Patents.
14. Chung, D., Electrically conductive cement-based materials. Advances in
cement research, 2004. 16(4): p. 167-176.
15. Earthing Techniques
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