Control method of energy storage system to increase output power from power conditioning systems (PCS)

This paper proposes an improvement method of a power generation amount of photovoltaic power generation system using energy storage system. Power conditioning systems (PCS) of the photovoltaic power generation system stops its operation when the generated power of the photovoltaic module is low as in cloudy weather. Even if the solar radiation recovers, the PCS restarts after an interval time. Therefore, the conventional photovoltaic power generation system can't fully extract the energy of photovoltaic module. This paper proposes a structure that the energy storage system is connected between the photovoltaic module and the PCS. This paper also proposes control method of the energy storage system. The effectiveness of the proposed system is verified by experimental results. The electric power amount of photovoltaic module in the case of applying the conventional discharge control method and the proposed discharge control method was compared. When using the conventional discharge control method, electric power amounted to 7.4 Wh. On the other hand, when the proposed discharge control method was used, electric power amounted to 8.5 Wh. The electricity amount of photovoltaic module improved by 14.9%.