The reliability evaluation of a power system in presence of photovoltaic and wind power generation plants and UPS

In this paper a system in which a photovoltaic plant (PV) and a mini Wind plant integrated in a Uninterruptible Power System (UPS) is presented. The aim is to reduce the critical loads loss due to long interruption of the main supply, using the power produced by renewable sources. Obviously the critical load loss depends on many stochastic variables: main supply interruptions, battery capacity and weather condition; so to evaluate the reliability of the system is not a easy task. In the paper, the attention is focused on the estimation of the evaluation of system reliability and its improvement respect to a conventional UPS. 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.