DESIGN AND IMPLEMENTATION OF A FAULT DETECTION AND LOCATION SYSTEM FOR AN UNDERGROUND POWER DISTRIBUTION CABLE

Dept: ELECTRICAL ENGINEERING File: Word(doc) Chapters: 1-5 Views: 15

Abstract

Electrical energy is the most convenient form of energy since it can be converted to almost all other forms of energy in the cheapest and most efficient way. Electrical power must be delivered to consumers in a safe, efficient, economical and reliable way. This makes it necessary to have power systems which will guarantee all these requirements. Currently the Tanzania electric supply company (TANESCO) lacks a proper method of fault location in the distribution level and more so in the underground lines. The company has a limited length of underground and marine power lines but plans to employ underground power lines in distribution level especially in urban areas and a major project is on-going at Ilala area in Dar-Es-Salaam. Fault detection and location is most difficult in underground lines. This project was aimed at designing an accurate, cost effective and on-line fault detection and location system for underground distribution power cable. This was achieved through reviewing the

CHAPTER 1: INTRODUCTION

Introduction

This is the first chapter of this project report and is intended to give some background information on power distribution system alongside fault detection and location. It comprises Problem definition statement, project performance specifications & limitations, scope and limitations block diagram of the proposed system, project objectives, deliverables and report outline.

1.1 Background and Problem definition statement

Power supply companies are sometimes forced to employ underground power transmission and distribution lines rather than their overhead counterparts. This is mostly for safety and neatness reasons. Currently, the Tanzania electric supply company (TANESCO) has a limited length of underground and marine power lines but have plans to employ underground power lines in distribution level especially in urban areas. One major project is already on-going in Ilala area, Dar-Es-Salaam city. One of the major challenges associated with underground power cables is the difficulty in locating the actual point of fault and consequently prolonged ‘out of service’ time. Currently there is no perfect fault location system for underground power cable and this introduces an issue to fault location in the marine and the expected underground distribution lines.

The process of fault detection, location and fixing appears much more difficult and time consuming in underground systems as compared to overhead systems solely because the utility company currently lacks a proper fault location technique. This project has aimed at designing and building an accurate and affordable system of underground cable fault detection and location.

1.2 Performance specifications and constraints

The proposed system performs according to the following technical specifications:

i)       

The system detects and locates short circuit faults of line to ground categories.

ii)     

The system is able to detect and locate the fault by indicating both fault current and distance in kilometers from the control room of the substation.

 The following were the chief constraints to this project.

i)       

Inadequacy of funds for research and physical implementation. The amount of money issued by sponsors was 100,000 TZS only.

ii)     

Time limitation. The available time for accomplishment of the project was limited to eight months. This was not sufficient for undertaking researches on all aspects required for the accomplishment of this project and in turn led to omission of some of the aspects as well as narrowing the scope of the project which otherwise would have covered all types of faults.