Design techniques of distributed photovoltaic/energy storage system

The intermittent and fluctuating energy sources such as photovoltaic power generation system may cause impact on the power grid. In this paper, the key technologies and control methods of distributed photovoltaic / storage system are systematically studied. This paper introduces the overall design scheme and main function of the integrated system include energy storage and distributed photovoltaic, then discusses the design principle of different module and subsystem, such as storage battery banks, bi-directional converters, measurement and monitor system and energy management system. The novel estimate algorithm of state of charge in battery and control method of photovoltaic / storage system were proposed. The field operation data show that photovoltaic / storage system can be used to stabilize the power fluctuations from photovoltaic to grid, adjust grid voltage of common connection point and increase income base of the power tariff in peak and valley.