Repair duration effects on distribution system reliability indices and customer outage costs

The distribution system is part of the electric power system that links the bulk transmission system and the individual customers. Approximately 80 percent of outages experienced by the customers are due to failures in the distribution system. It is therefore important to understand the impact of the outages on the customer outage costs and the system reliability. This thesis evaluates various analytical and simulation techniques which incorporate varying degrees of complexity and data to evaluate the expected customer costs at the system and load level of a radial distribution system. A computer program based on time sequential Monte Carlo simulation has been developed. The results show that certain analytical techniques provide as accurate results as using a Monte Carlo simulation technique. This research work then analyzes the effect of repair duration distributions on the expected customer costs and the system and reliability indices including annual outage duration at the load points using Monte Carlo simulation technique. Certain repair duration distributions caused expected customer outage costs to increase by 30% for the system and over 50% at certain load points. Some reliability indices were also directly affected by the application of repair duration distribution. This research work thus provides a basic guide to the difference in the expected costs and reliability indices when choosing a particular technique and the type of repair duration distribution