Improvement in the reliability performance of power distribution systems

Reliability assessment is of primary importance in designing and planning distribution systems that operate in an economical manner with minimal interruption of customer loads. Distributed Generation (DG) is expected to play an increasing role in emerging power systems because they use different type of resources and technologies to serve energy to power systems. DG is expected to improve the system reliability as its backup generation. Since DG units are subject to failures like all other generation units, the random behavior of these units must be taken into account in the analysis. Existence of DG units in a distribution system will effect on restoration time of load points. The algorithm for restoration time assessment of load point is developed when DG unit is installed. In this paper, the reliability performance of distribution system is analyzed in terms of SAIFI, SAIDI, CAIDI, ASAI, ASUI, ENS and AENS. The algorithm to calculate the reliability indices for simple 9-bus radial distribution feeder with and without DG is developed. The improvement in the reliability of the feeder is studied for different locations of DG with respect to fault point. All the above analysis is carried out by developing MATLAB software.