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