Distribution System Reliability Evaluation Using Both Analytical And Simulation Approaches

Abstract

The distribution system is the segment in an overall electric power system that links the bulk system and the individual customers. This section contributes approximately 80 percent of the total customer interruptions. It is therefore an important factor in providing an acceptable level of customer service and it is necessary to evaluate the impact of different distribution configurations and operating models on system reliability. This thesis presents a generalized analytical technique to extend and simplify the procedure for determining the reliability of a distribution system with branches and with different operating schemes. In this approach, a series of general segments are defined to construct a general feeder (a simple distribution system). A set of equations for calculating the basic load point indices of the general feeder is developed. Network reliability equivalents are used to reduce a complex distribution system into a simple distribution system. A digital computer program has been developed using this analytical approach to evaluate distribution system reliability indices. The thesis also illustrates the application of the time sequential Monte Carlo simulation technique to complex radial distribution system reliability evaluation. A simulation procedure is illustrated and a computer program has been developed using the simulation approach to evaluate both the average values of the reliability indices and their probability distributions. The two developed computer programs are illustrated in this thesis by application to the distribution systems of the Roy Billinton Test System. The results obtained by the analytical approach are compared with those obtained by the simulation method. Both approaches are shown to be very useful in the reliability evaluation of practical radial distribution systems.