A Study Of Effect Of Dust Accumulations On 33kV Line Insulator

ABSTRACT

Insulators are mainly used to support and insulate the overhead lines and electric equipment and play an important role in ensuring safe and stable operation of the power system. With increasing industrial level in China, atmospheric pollution and outer-insulation pollution of power system are becoming more and more serious. Outdoor equipment of substation and transmission line is easy to be polluted by industrial dust, raise dust others. This paper studies the impact of dust accumulation on 33kv line insulator and also identifies challenges to further research in this area.

TABLE OF CONTENTS

COVER PAGE

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWELDGEMENT

ABSTRACT

CHAPTER ONE

1.0      INTRODUCTION

1.1      BACKGROUND OF THE PROJECT

• PROBLEM STATEMENT
• AIM AND OBJECTIVES OF THE PROJECT
• SIGNIFICANCE OF THE PROJECT

CHAPTER TWO

LITERATURE REVIEW

• REVIEW OF RELATED STUDIES
• POLLUTION FLASHOVER OF INSULATORS
• OVERVIEW OF TRANSMISSION LINE INSULATORS
• PROPERTIES OF INSULATORS
• TYPES OF INSULATORS
• FAILURE OF INSULATORS

CHAPTER THREE

3.0     METHODOLOGY

3.1      MEASURING EQUIPMENT

3.2      MEASURING PROCESS

CHAPTER FOUR

4.1      ANALYSIS OF TEST RESULTS

4.2      METHODS FOR REDUCING THE EFFECT OF DUST POLLUTION

CHAPTER FIVE

• CONCLUSION
• RECOMMENDATION

REFERENCES

CHAPTER ONE

1.0                                                        INTRODUCTION

1.1                                           BACKGROUND OF THE STUDY

The theft of energy conveyance from generating plant to load centers is transported by overhead lines [1]. The stimulated high voltage line conductors not just must be physically joined to the bolster structures additionally electrically secluded from the bolster structures. The device used to play out the dual utility of support and electrical detachment is the outside high voltage encasing (insulators).

The most key segment that chooses the physical estimations of outside encasings is their execution under tainting conditions. Dependent upon the pollution earnestness and the wetting conditions of the site, outside spreads require satisfactory surface leakage length to ensure that dry band advancement and surface arcing is restricted.

Many years of in-service execution have shown that ceramic insulators, made of porcelain and glass, demonstrate great execution and oppose ecological maturing. Furthermore to upsurge mechanical quality, they give incredible imperviousness to material degradation brought on by electrical anxiety and discharge activities [2]. In any case, they experience the ill effects of having hydrophilic surface properties, which implies that water can undoubtedly shape a constant conductive film along the creepage way, in this manner permitting high surface leakage currents to stream on their wetted surfaces. Such currents cause dry bands at zones of high current density and lower wetting rates, which in the long run cause surface arcing and frequently finishes flashover of the encasing.

Amid late decades, polymer insulators have been presented and generally utilized at distribution voltage levels because of their better contamination execution. Right now, encasings made of polymeric materials are frequently called composite or non-ceramic encasings. Non–ceramic encasings, for example, silicone rubber, offer a few focal points over porcelain encasings. They have excellent hydrophobic (water-repellent) surface properties under wet conditions; this property limits the leakage current and the likelihood of dry band enlargement. Additionally, they have high mechanical strength to weight proportion, resistance against vandalism, and decreased upkeep costs [3]. Nevertheless, polymer materials have weaker silicone to oxygen (Si-O) bonds than porcelain materials so they are more vulnerable to chemical degradation under the various anxieties prone to be experienced in service; including stress because of high functioning voltages, UV rays and contamination sullying.

Dust particles are the main solid components of atmospheric aerosols [4]. They come from geo-physical movements and human activities and can impose a significant impact on climate or local environment [4]. Dust events occur in forms of blowing sand, floating dust, sandstorm, and haze if PM2.5 taken into account. All of these extreme weather events have long been bothering the vast areas. On the one hand, dust particles could be
transported into densely populated districts through atmospheric circulation, bringing some unfavorable influence on human health. On the other hand, it should also be noted that dust events could be a severe threat to the operation of certain industries, especially the power transmission industry [5]. Overhead transmission lines are vulnerable to environmental pollution, or more precisely, the dust pollutants that deposited and accumulated on the surface of line insulators, combined with moisture in the air, will promote the surface conductivity, causing an increase in leakage current [6]. The polarization and thermal effects of the current will accelerate the aging of insulating materials, thus greatly enhance the probability of breakdown and pollution flashover of the latter, leading to short circuit and even power outage (Castillo Sierra et al. 2015). Such accidents did happen every now and then in recent years, and with more long-distance high-voltage transmission

1.2                                                  PROBLEM STSTEMENT

The primary function of the insulator is to separate the conductor from the transmission tower in the transmission line. They create a barrier between the active parts of an electrical circuit and restrict the flow of current to wires or other conducting paths as needed.

In a wire, an electric current occurs when the electron moves. Since insulators have tightly bound electrons they are stationary and do not move throughout the substance. They serve to hold the current in position and separate the pole from the conductor to avoid leakage of current to earth.

An insulator gives support to the overhead line conductors on the poles to prevent the current flow toward earth. In the transmission lines, it plays an essential role in its operation. Dust particles suspended in the atmosphere have been a big headache for electric power transmission industry in Nigeria. As transmission lines pass through dusty or air-polluted areas, dust contaminants are likely to deposit and accumulate on line insulators, which is one of the greatest headaches of power transmission.

1.3                                    AIM AND OBJECTIVES OF THE STUDY

The main aim of this work is to study the impact of dust deposition on the performance of high voltage insulators. The objectives are:

1. To identify how dust accumulation can affect distribution line insulators.
2. To identify challenges to further research in this area.

• To study a method of removing dust from the insulator

1.4                                           SIGNIFICANCE OF THE STUDY

This study will serve as a means of looking at dust accumulation on insulators, with a view to more correctly identifying applicable service conditions and better specifying insulators.

This work will also serve as means of studying how dust accumulates transmission line and its effect on transmission lines.

The study will also help the High voltage engineers to understand how to maintain insulators when they are polluted by dust.