A reliability assessment methodology for distribution systems 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. With the advances in renewable energy sources, distributed generation (DG), is forecasted to increase in distribution networks. This paper presents a new methodology that can be used to quantitatively analyze the reliability of such distribution systems and can be applied in preliminary planning studies for such systems. The method uses a sequential Monte Carlo simulation of the distribution system's stochastic model to generate the operating behavior. This is combined with a path augmenting Max flow algorithm to evaluate the load status for each state change of operation in the system. Overall system and load point reliability indices such as hourly loss of load, frequency of loss of load and expected energy unserved can be computed using this technique. The reliability indices can be compared for different scenarios and strategies for placement of DG using this methodology.