Application of Supercapacitors in Photovoltaic Power Generation System

In view of the intermittent and unstable output voltage of the photovoltaic power generation module, a supercapacitor is designed as the control system to improve the power quality and power supply continuity of the photovoltaic power generation system. The whole circuit includes a maximum power point tracking converter, a boost converter, a Hall element, a waveform recorder, and a supercapacitor bank. Because the output current of each solar photovoltaic module is very important for the control of the solar power generation system with a supercapacitor bank, a sensing circuit for accurately detecting the output current and current change rate of the solar power generation system is presented. When the sunshine is sufficient, the control system dispatches the output current of the solar photovoltaic module and provides power to the supercapacitor bank and the load terminal; when the sky is cloudy, the control system discharges the energy stored in the supercapacitor as an uninterruptible power source and provides power to the load such that the load terminal voltage is stable. The measured results show that the control system can effectively suppress the output voltage fluctuation of the photovoltaic power generation module, improve the power quality, and enhance the reliability of load power consumption.