Solar energy is an unstable energy source, due to the sunshine radiation degree determines the photovoltaic module output power, the change of light intensity makes the output power of photovoltaic cell change, with a great deal of randomness, which brings obstacles to the stability of the system after PV grid-connected, PV power consumption and PV power station power quality, restricting the development of photovoltaic power generation. How to make the output power of PV power generation stable and controllable is a problem that must be solved in PV power generation technology. The introduction of energy storage devices can make the power output of PV power supply smoother, effectively changing or alleviating the randomness and volatility of PV power output. And supercapacitor as a kind of high-power energy storage element can solve the problem well.