Development of control unit for smart power supply system using battery energy storages and residential PV-PCSs

This research deals with the Non-Isolated Bidirectional Dc-Dc Converter (NBDC) control unit development for a smart power supply system using personal residential Photovoltaic-Power Conditioning Subsystem (PV-PCS), the results of circuits evaluation, and isolated PV-PCS operation connected battery storage (Electric vehicle storage etc.). The smart power supply system using the existing residential PCS with battery storage has an advantage that it can suppress the energy change during normal operation and can also construct the isolated power supply in an emergency case of power system cut-off. In PV power generation, PV power fluctuations caused by weather changes make the difficulty to obtain stable power output. Further, it can be expected that this adversely affects to the power system. By using this smart system control with an isolated power supply function, this battery storage can be provided the power for critical loads during the utility outage. In this paper, the comparison of voltage control mode in terms of battery voltage range is considered for the smart system operation. In particular, IGBT power semiconductor gate drive circuit of light insulation and current-voltage detection circuit with used photo-coupler of light insulation are newly developed for the smart power supply system operation. Moreover, the isolated power supplies effectiveness, the smart circuit development, and the experiment results of the PV-PCS interconnection isolated power system for stable supply with the existing residential PV-PCS of Japan are investigated, analyzed and discussed.