Reliability assessment of distribution system with distributed generation

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 as 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. In this paper, an algorithm for assessing restoration time of load points for a radial distribution system with back up DG units is presented. The Impacts of DG units, their location, number of DG units in each location and their availability, on distribution system reliability are investigated using a real distribution network in Tehran utility/Iran.