Reliability cost/worth considerations in distribution system evaluation
Reliability cost/worth assessment plays an important role in power system planning, operation and expansion as it provides an opportunity to incorporate customer concerns in the analysis. This thesis focuses on the reliability cost/worth analysis of radial distribution systems. Distribution system reliability indices can be evaluated using analytical methods or by Monte Carlo simulation. The sequential simulation technique makes it possible to incorporate the time varying and random nature of load and cost models in the reliability evaluation. This simulation technique can also provide a wide range. of indices and their probability distributions. This research work focuses on distribution system reliability cost/worth evaluation. The main objectives are: (1) the development of analytical and time sequential simulation techniques to evaluate reliability cost/worth indices, (2) the utilization of these techniques in optimal planning and operation decisions, (3) an examination of the effect on reliability worth prediction of time varying load and cost models, and the dispersed nature of cost data, and (4) the consideration of wind generation as an alternative supply in a radial distribution system. An analytical technique designated as the reliability network equivalent approach has been developed to improve the computing efficiency of the conventional failure model and effect analysis method for distribution system reliability evaluation. A time sequential simulation approach is also developed and used to evaluate the basic distribution system reliability indices and their distributions. A generalized analytical technique and a time sequential simulation technique in which the time varying nature of the load and cost models are incorporated in the analysis have been developed and used to evaluate reliability cost/worth indices. These indices are utilized in an optimization process to determine the optimal number of switches and locations in a distribution system. A bisection search technique Is used to simplify the optimization procedure. This thesis also recognizes the impact of different load and cost models and the dispersed nature of cost data on the distribution system reliability indices. The time varying load and cost models for seven different customers have been developed and illustrated The effect of the time varying load and cost models on reliability worth is illustrated by application to several test distribution systems. The effect on the reliability worth indices of the dispersed nature of the cost data is also considered in the, simulation technique. Economic and environment concerns have created an increased interest in the use of wind Economic and environment concerns have created an increased interest in as an alternative energy source. The impacton the reliability performance of a distribution system of using wind generation as an alternative supply is investigated. The effect of different wind sites and wind turbine generator parameters on system reliability is examined.