Abstract
In the last years, there was an increased interest in distributed generation. In particular, national and international government has developed incentives programs for installation by final customer small size photovoltaic, wind and CHP plants. In this context the concept of micro-grid (MG) arises. The term of MG is taken to mean a subset of power distribution systems that contains sufficient local energy sources to supply most or all of the local loads. Then, with the penetration of MG there are a wide variety of potential benefits for the customer: reduced price volatility, greater reliability and improved power quality. In this paper the attention is focused on the concept of reliability. On this subject the authors have proposed, in previous papers, opportune configuration schemes of a MG constituted by a PV plant, a wind plant and an storage system. Then, the goal of this paper is to evaluate the reliability improvements of load supply against network congestions adopting the proposed MG configurations and taking into account the randomness of renewable sources (sun and wind) and of the power required by the load. In particular, the reliability estimation is performed in terms of the number of the critical loads interruptions, over a certain period of time by using the Monte Carlo simulation method.