Energy Audit and Reliability Analysis of Afe Babalola University Power Distribution System

Introduction

Electricity supply is the bedrock for industrialization, economic and social development in any country. It is therefore desirable that electric power supply to consumer be reliable, adequate, and at a minimized maintenance, operational and constructional cost (Ayamolowo et al., 2017). Reliability assessment is used as a standard tool for planning the design, operation and maintenance of electric power systems aimed at providing uninterrupted electric power supply to consumers (Kehinde, 2013; Oluwafemi et al., 2019).

According to Kehinde (2013); Ahmad (2017); Ayamolowo et al. (2017), distribution system failure accounts for 85 to 90 percent of the total power unavailability when compared with failure of other sections of electric power systems, therefore reliability assessment of distribution system is important to ensure formidable and effective power systems. The inclusion of distributed generators (DGs) in a distribution system helps to improve the overall reliability of the electrical network, reduces system loss and assists in meeting the overall power demand of the system (Pal & Ghosh, 2012; Martinez-Velasco & Guerra, 2016).

DGs can be made to operate in two modes:

• i.

  DGs operate as a backup source within a micro-grid

• ii.

  DGs operate in parallel with the distribution system

Power Distribution System

Distribution system design can be classified according to their topology as Radial, Loop and Meshed structure. Figure 1 shows the various distribution systems topology with Figure 1(a) having the simplest architecture. In this configuration, each substation or customer is connected through a transmission line to a central point. This system is designed for uni-directional power flow with no redundancy in view. This configuration is limited as it has a longer duration for repairs (MTTR). Figure 1 (b) shows the loop configuration in which case all substation or customers are connected via double line. During a disturbance, the faulted section is easily isolated and restored once repaired. Figure 1 (c) shows the meshed structure with all substation and consumers connected via more than two lines. This design has an improved reliability, reduced downtime and repair time (Ahmad, 2017).

Figure 1.

(a) Radial structure (b) Loop structure (c) Meshed structure.