An Assessment of Distribution System Reliability of PHCN A Case Study of Aba District

An Assessment of Distribution System Reliability of PHCN

Project / Seminar Material
Reference ID: PS-1930-TM

DEDICATION

This research material titled “An Assessment of Distribution System Reliability of PHCN” is dedicated to God for his enabling grace, and to all computer enthusiasts who contributed to make life a pleasant experience during my research documentation.

ACKNOWLEDGEMENT

I extend my sincere gratitude to all those who contributed to the completion of this project. Special thanks to my Supervisor (Name of your Supervisor), the Head of Department (Name of your HOD), the Lecturers in the department of Electrical / Electronics Engineering (EE), Book Authors and Profound Scholars of existing or related project material on “An Assessment of Distribution System Reliability of PHCN” for their invaluable guidance, support, and expertise throughout the journey.

I am also grateful to your study area (mention any funding organizations, if applicable) for their financial assistance. This research would not have been possible without the encouragement and assistance of some stakeholders (mention any mentors, teachers, or colleagues). Additionally, I would like to acknowledge the understanding and patience of my family and friends during this endeavor. Your unwavering support has been a constant source of motivation. Thank you all for being part of this meaningful endeavor.


An Assessment of Distribution System Reliability of PHCN (A Case Study of Aba District)

TABLE OF CONTENTS

PRELIMINARY PAGES


CHAPTER ONE
1.1: Introduction
1.2: Definition of terms
CHAPTER TWO
2.1: Literature review
CHAPTER THREE
3.1: Research methodology
3.2: Sampling of techniques
3.3: Source of data
3.4: Validation of instruments
3.5: Techniques of data analysis
CHAPTER FOUR
4.1: Case study Aba distribution Network
  • Table 1: Monthly peak load and number of consumers on Aba network.
  • Table 4.2: Summary of fault data for Aba network (2006)
  • Table 4.3: Summary of fault data for Aba network (2007)
  • Table 4.4: Summary of fault data for Aba network (2008)

4.1.1: Computation of fault intervals/mean
4.1.2: Computation of variance
  • Table 4.5: table of values for F(x-x)2

4.1.3: computation of Expected frequency
4.1.4: Computation of chi-square
  • Table 4.6: Fault intervals, observed frequencies calculated or expected frequencies, mean, variances and calculated chi-square for Aba network

4.2: Computations of reliability indices operating in hour:
4.2.1: Failure rate for months in hours
4.2.2: System reliability for months
4.2.3: failure distribution functions for the system:
4.2.4: Life time cumulative distribution function (CDF) operating in hours
4.2.5: Life probability distribution function (PDF)
  • Reliability R(t) operation time in hours.
  • Table 4.7: Reliability indices for Aba

CHAPTER FIVE
5.1: Discussion
5.2: Summary
REFERENCES

ABSTRACT

In the recent past various attempts have been made to improve the adequacy of power supply and reliability of the supply network. This project work focuses on the reliability of the distribution system of PHCN with Aba distribution network as case study, using daily fault report data for three years viz: 2006, 2007, and 2008.

The Poisson distribution and the chi-square were used to determine the appropriateness of the observed data collected. In other words, the chi-square was used to asses the goodness of fit of the Poisson distribution hypothesis at 0.05 level of significance.

Lastly, the project work estimates the reliability indices of failure rate R(t), system reliability R(t), failure density function F(t) and system interruption frequency index.


An Assessment of Distribution System Reliability of PHCN (A Case Study of Aba District)

CHAPTER ONE

1.1 Introduction

Distribution networks differ from transmission networks in quite a number of ways, ranging from voltage magnitude to the number of branches and sources. The number of branches and source is mush higher in distribution networks and the voltage magnitude lower. Its general structure of make up is quite different from that of the transmission networks.

A typical distribution system consist of a step- down transformer e.g. 132/11kv, at a bulk supply point feeding a number of cables. In a series of step-down three-phase transformers e.g. 11kv/415v, are spaced in route and from these, the consumers are supplied three-phase, four wire networks which gives 240V single phase to houses and other similar loads.

The objective of power system is to maintain a continuous and adequate power supply to its consumers at a reasonable rate of return. In Nigeria, this objective is far fetched. Hence, there is the need to focus our attention on reliability as a way of assessing and improving the “wire business” as well as optimizing our investment in the distribution network.

It has been observed that a major part of service interruptions experienced by consumers has its origin in failure from the distribution system (mostly 33kv and below in Nigeria, with radial arrangement and the distribution system reliability studies have been hindered due to the unavailability of component outage on the distribution system.

Thus, the need to maintain a reliable and effective electrical service to consumers using the available apparatus on the system is very important and necessary.

In this project, the assessment of distribution system reliability can be facilitated using Poisson model, with PHCN Aba as case study.


1.2 Definition of Terms


1.2.1: Reliability:

Can be define as the ability of an item/equipment/system to perform a required function under a stated condition for sated period of time.


1.2.2 Failure Rate:

This is the number of faults or failure per unit time and symbolized by ?.


1.2.3: Mean Time Before Failure (MTBF):

This is the mean value of the length of time that elapses between failures.


1.3: Causes of Faults:

Faults could be caused by the following;

  1. Lightning strokes
  2. Strong swind
  3. Tree falling across
  4. Vehicles collision with tower/poles of consumers
  5. Erosion of tower/poles foundation
  6. Vandalization
  7. Illegal operation of consumers

CHAPTER TWO

2.0 Literature Review

2.1 Introduction

This chapter focuses on the review of related literature. A literature review includes the current knowledge as well as theoretical and methodological contributions to a particular topic. It documents the state of the art with respect to the topic you are writing. It surveys the literature in the topic selected. In this research work the literature review includes the …

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