Design And Analysis Of Over Voltage Protection System In A Distribution Network

Abstract

Overvoltage happens in a condition where the voltage is increased and exceed its design limit. This situation may lead to harmful damage to machines or related equipment that connected to the system. Overvoltage can exist in a form of transient, voltage spike or permanent, depending on its duration. Along with increasing importance of power quality the effect of overvoltage protection to short interruptions and voltage dips is of great importance. With advanced reliability analysis tool integrated to network information system, the effect of protection can be studied. This study is aimed at carrying out an analysis of over voltage protection system in a distribution network.

Chapter One

INTRODUCTION
1.1 BACKGROUND OF THE STUDY
Protection systems are vital components of any power system. Its goal is to detect and isolate faults when they occur. By doing so, safe operation of power systems can be achieved, extensive equipment damage can be avoided and the areas affected by faults can be minimized.
The overvoltage protection of distribution networks is quite challenging task. The traditional reason for overvoltage protection has been prevention of failure of expensive components like transformers. Along with increasing importance of power quality the effect of overvoltage protection to short interruptions and voltage dips is of great importance. This means that overvoltage protection should be deeply modeled and analysed as part of reliability based network analysis. For example, selection of using surge arresters instead of spark gaps in transformer protection is not necessary based on the transformer itself but the consequences of short interruption and voltage dips due to arcs in spark caps. This paper presents different types of strategies which can be applied in overvoltage protection planning but focusing mainly on the use of surge arresters which is been modeled in this work.

1.2 PROBLEM STATEMENT
Power distribution systems are directly linked to customers. Thus the distribution system plays an important role in the overall power system reliability and the perceived reliability to customers. By improving distribution protection systems such that sustained outage times can be reduced, power system reliability can be enhanced.
For every power distribution system lightning discharges are one of the most significant disturbances, since it can give origin to overvoltage and consequent influences on the quality of the power supply. Among several consequences of the incidence of any lightning discharge, one of the most significant is the transference of voltage surge between primary and secondary windings of any power distribution transformer. The degree of transference basically depends on the frequency response of the transformer (Cabral et al, 2010) as well as on its grounding impedance. Thus, several studies have been carried out by analyzing transferred or induced voltages due to lightning discharges through grounding systems (Visacro et al, 2012).
This work studies the analyses of such kind of overvoltage require the utilization of reliable modeling to represent all the elements involved in this process. In this work distribution transformer modeling is considered using surge arrester.

1.3 AIM AND OBJECTIVE OF THE PROJECT
This work is aimed carrying out an analysis of over voltage protection system in a distribution network.
The objective of this work is:
• Provide a solution to voltage in a power system.
• To presents a model for the analysis of overvoltage in power distribution network caused by lightning discharges.
• To carry out a simulation of overvoltage protection scheme using surge arrester.

1.4 SIGNIFICANCE OF THE STUDY
As a student of electrical and electronic engineering, working on this project has expose my knowledge to causes and solution to over-voltage protection system in a distribution network. It has made me to understand how surge arrester can be model in a distribution network.

1.5 SCOPE AND LIMITATION OF THE STUDY
The scope of this work covers the modeling of a overvoltage protection scheme based on the use of surge arresters on a distribution network. In this work surge arresters are mounted on an additional wood crossarm, considerably closer to the transformer terminal bushings. The total length of the surge arrester connection conductors is 6 m and 1.1 m for the common practice and the alternative protection scheme, respectively.
There are different methods of carrying out a protection scheme in a power system, but in this work only the use of surge arresters was studied.

Table of Contents

Cover page
Title page
Approval page
Dedication
Acknowledgement
Abstract

CHAPTER ONE
INTRODUCTION
1.1 Background of the project
1.2 Problem statement
1.3 Aim and Objective of the project
1.4 Significance of the study
1.5 Scope and limitation

CHAPTER TWO
LITERATURE REVIEW
2.1 Review of the study
2.2 Overvoltages and overvoltage protection
2.3 Causes of over voltage in power system
2.4 Lightning, switching and temporary over voltage
2.5 Effects of over voltages on power systems
2.6 Review of overvoltage protection
2.7 Methods of protection against lightning
2.8 Insulation coordination

CHAPTER THREE
Methodology
3.1 Modelling of the evaluated system

CHAPTER FOUR
4.0 simulation results and discussion

CHAPTER FIVE
5.1 Conclusion
5.2 Recommendation
References

Research Guidelines

The Title Page should be the first section of your project “Design And Analysis Of Over Voltage Protection System In A Distribution Network”, providing essential details like the project title, your name, your supervisor’s name, the institution, and the submission date. After that, the Abstract offers a brief summary of your project, touching on its purpose, methods, results, and conclusions in 150-300 words. The Acknowledgments section is where you can thank those who supported your research, such as your supervisor, peers, or organizations that provided resources.

Next, the Table of Contents organizes the Design And Analysis Of Over Voltage Protection System In A Distribution Network by listing its chapters and sections, along with page numbers for easy reference. The List of Figures and List of Tables help guide readers to specific visual elements like graphs, charts, or tables included in the document. There should also be an Abbreviations and Glossary section to explain any specialized terms or acronyms, making the content clearer to readers unfamiliar with the technical language.

The main body of the Design And Analysis Of Over Voltage Protection System In A Distribution Network should start with the Introduction, which provides background information, outlines the research problem, states your objectives, and gives a brief overview of your research methods. Following that, the Literature Review offers an in-depth look at previous research relevant to your project, identifying gaps your study aims to address. The Methodology section then explains the research design, tools, and data collection methods you used to conduct the project and analyze the data.

In the Results and Discussion section, you present your findings and discuss them in relation to the Design And Analysis Of Over Voltage Protection System In A Distribution Network research questions or objectives, often using tables or charts to help explain the data. The Conclusion summarizes the key results, discusses their implications, and suggests possible directions for future research. You may also include recommendations based on your findings, offering practical advice for improvements or applications. Finally, the Design And Analysis Of Over Voltage Protection System In A Distribution Network project should include a References or Bibliography section to list all the sources you cited, as well as Appendices for any additional material. A Statement of Originality is often included to confirm the authenticity of your work