DESIGN AND IMPLEMENTATION OF UNDERGROUND CABLE FAULT DETECTOR

DESIGN AND IMPLEMENTATION OF UNDERGROUND CABLE FAULT DETECTOR

CHAPTER ONE

INTRODUCTION

1.1 BACKGROUND OF STUDY

Electric energy is an essential ingredient for the industrial and all-round development of any country. It is the most popular form of energy, because it can be easily converted into most form of energy, also it can be generated centrally in bulk and transmitted economically over long distances. Further, it can be adapted easily and efficiently to domestic and industrial applications, particularly for lighting purposes and mechanical works e.g. drive (Kothari and Nagrath, 2009).

Over thousands of   miles of electrical cables are strung overhead across the country.  Also added are the  telephone  and  cable  TV  lines,  and  it’s  no  wonder heavy storms, heavy wind from heavy rainfall  are  wreaking havoc  on  the  electrical  systems  each  year,  causing  utility outages  that  last  days,  weeks  and  longer.  Power  outages over  extended  periods  present  major  health  and  safety concerns  and  economic  losses.  

Concerns  about  the reliability  of  overhead  lines,  increases  in  their maintenance  and  operating  costs,  and  issues  of  public safety  and  quality-of-life  are  leading  more  and  more utilities  and  municipalities  to  the  realization  that converting  overhead  distribution  lines  to  underground  is the  best  way  to  provide  high-quality  service  to  their customers.  For  utility  companies,  undergrounding provides  potential  benefits  through  reduced  operations and  maintenance  (O&M)  costs,  reduced  tree  trimming costs,  less  storm  damage  and  reduced  loss  of  day-to-day electricity  sales  when  customers  lose  power  after  storms. Creative  funding  options  are  often  available  to  make  the goal  of  undergrounding  a  reality.

 For most of the worldwide operated low voltages and medium voltage distribution lines, overhead cables which is been used for many decades are now been replaced with underground cables. Underground cabling are more superior to overhead to an extent and are used more and more because they are not influenced by weather conditions such as; heavy rain, storm, snow and pollution. Nowadays underground cabling systems are much important for distribution especially in metropolitan cities, defense service and airports. Despite the improvement in cable manufacturing technologies, there are still influences which may cause cable to fail during test and operation. A cable in good condition and installed correctly can last a lifetime of about 30 years. However cables can be easily damaged by incorrect installation or poorly executed jointing, while subsequent third party damage by civil works such as trenching, curb edging etc. Gilbert, Yuan and Tobias (2016).

According to Hadi saadat, (1999), Underground cables have been used for decades, the first electric network in the United States was established in 1882 by Thomas Edison. The power was generated by dc generators and distributed by underground cables. The  underground  cabling system  is  very  important  for  distribution  especially  in metropolitan  cities,  airports  and  defense  service.

Underground distribution systems are valuable assets of electrical utilities, which supply power to the end customers at low voltages. Many of the system components, particularly underground cables, fail over time, in part due to the deterioration of the insulating materials used in their structure. Studies reveal that cable failure rates in power systems continue to worsen as the cable ages. National rural electric cooperation (1993).

In the past, analogue system was used to detect and locate fault in underground cabling, however the need for improvement has made it necessary to shift from analogue to digital system of fault detection and location. This shift requires new tools and methods to detect and locate faults of underground distribution systems. In view of this consideration, this project is aimed at designing and constructing an underground cable fault detector.

DESIGN AND IMPLEMENTATION OF UNDERGROUND CABLE FAULT DETECTOR