Abstract
M.Ing. (Engineering Management)
The electrical power is a basic public service. The electrical power reliability is very essential since most of the infrastructures are dependent on it. Unplanned power outages may compromise the services such as transport, communications systems and emergency and the security services. Unplanned power outages are also inconvenient and very costly to both commercial and residential customers.
As a result, the research study identify the factors that contribute to poor reliability of distribution networks and from the findings the alternative strategies are proposed and discussed. The study is intended to help electrical utilities such as municipalities to efficiently investigate the distribution network that is affected and apply the scheduled reliability development tactics to achieve the best performance. The literature review was carry out to review the existing body of the knowledge in relation to the root causes of unplanned power outages, overview of distribution reliability performance indices and the solutions that can be used to improve the performance of distribution system.
A case study strategy was presented within one of the Gauteng Metropolitan Municipality with three year (2015-2017) historical power outage data of medium voltage feeders. It was found that most of these failures of medium voltage feeders under the case study take place due to equipment failures contributing high (total of 37 fault incidents in three years). Equipment failures presented a high risk, in particular the LV (Low voltage) transformer fault. Overhead line faults contributed to total of 29 fault incidents, 25 faults incidents for underground cable faults, 14 fault incidents for copper/cable theft, 12 fault incidents for electricity theft, 9 fault incidents for vandalism and 7 faults incident for extreme weather events. New factors such as motor vehicle accident, Feld fire and found no fault (unknowns) were discovered from the case study and not covered from the literature review.
Metropolitan Municipality currently uses only expected reliability indices of each year to assess the distribution network performance. The research study presented the predictive reliability assessment strategy that can be used by managers and engineers of the municipality for predicting the distribution network problems of medium voltage feeders, which is by using the probability distribution of both SAIFI and SAIDI of each year.