Coordinated control and energy management of hybrid energy storage system in PV system

The present work deals with development of new control strategy for hybrid energy storage system (HESS), consisting of photovoltaic (PV) system, battery, supercapacitor (SC) and load. Due to the variable characterstics of non-conventional power generation and variable load demand, batteries can undergo irregular, partial charge/discharge cycles. It has detrimental effects on battery life span and rating. The proposed strategy uses the DC bus voltage and battery state of charge (SOC) for charging/discharging of battery. In the proposed method, the battery system is coordinated with SC by diverting short-term charge/discharge cycles to SC if the SOC is within the limits. In case of SOC limit violation, battery SOC is controlled by diverting charge/discharge currents to SC. The digitial simulation results are presented and discussed to verify the validity of the proposed control strategy.