Solar photovoltaic power generation system is the use of photovoltaic effects of the sun battery semiconductor materials, the solar radiation directly into electricity of a new type of power generation systems, have an independent operation and parallel operation in two ways. Stand-alone photovoltaic power generation system needs a battery as energy storage devices, mainly used in remote areas and dispersed population areas without power grid, the system cost is very high; In the area of public power grid, photovoltaic power generation system connected to the power grid parallel operation, save battery, not only can reduce the cost, but also has higher efficiency and better environmental performance.