Unified Approach to Reliability Assessment in an Isolated RES System

Due to their unique characteristics, renewable energy sources (RES) are an ideal energy source for small isolated power systems (SIPS). At the same time, the reliability impacts of RES electricity supply should be carefully studied, especially in SIPS with significant RES installed capacity. One of the most potent methods for this purpose is system well-being analysis, accounting for deterministic and stochastic reliability factors. In the paper, we present a novel method for calculation of system well-being indices based on contingency enumeration (CE) method. We also investigate the energy-oriented energy not served (ENS) index and propose an improved method for its calculation. The indices are then used to analyze the impacts of different hybrid generation structures and RES penetration levels on supply reliability of the system. We investigate the suitability of different reliability assessment schemes and pertaining indices for reliability of hybrid energy sources in SIPS. The results show-that due to the ability of the ENS index to measure the severity of the risky state, both types of indices are needed to satisfactorily observe the supply reliability, especially in hybrid-supplied SIPS