Control Method of Energy Storage System to Improve Output Power of PCS

This paper proposes an improvement method of a power generation amount of Photovoltaic (PV) system using energy storage system. Power conditioning systems (PCS) of the PV system stops its operation when the generated power of the solar panel is low as in cloudy weather. Even if the solar radiation recovers, the PCS restarts after an interval time. Therefore, the conventional PV system can’t fully extract the power of photovoltaic power generation. In the proposed structure, the energy storage system is connected between the PV and the PCS.This paper discusses conditions for power generation improvement of the PV system using energy storage system. Experiments using solar radiation data on sunny and cloudy days were carried out. On cloudy days PCS output improved by 5.38%. But on sunny days it decreased by 0.58%. The validity of the improvement condition was confirmed by experimental results.