Impact of hybrid energy storage system on solar power generation integrated in microgrids

Solar power generation is considered one of the most promising distributed generation (DG) technologies that is utilized in microgrids. Power intermittency and voltage swings of solar resource negatively affect the reliability of microgrids. Battery energy storage systems (BESS) are incorporated in such microgrids to mitigate the power intermittency of photo-voltaic (PV) system. However, this power intermittency can adversely affect the battery performance that lead to lifetime reduction. Accordingly, this paper presents an integration of hybrid energy storage system (HESS) in stand-alone PV systems. In HESS, battery and super-capacitor are used. The influence of HESS on battery state of charge (SOC), charge/discharge current and load voltage are investigated. HESS substitutes the PV power intermitted without hard stress on battery. Also, the performance of HESS is tested for both static and dynamic loads. From simulation results, both voltage swings and power intermittency have been enhanced which would increase the reliability of microgrids and the battery lifetime. The time domain simulations are accomplished using PSCAD/EMTDC software package. The obtained results can provide a useful guide for future planning and designing of microgrids.