The distributed power generation technology which is represented by solar photovoltaic power generation has been recognized for having the enormous advantages such as energy conservation and emission reduction, improving the reliability and flexibility of power system. In this paper, the research of photovoltaic dc system is used in 110 kV Zhegao substation in Chaohu Anhui province. The system is the first set of substation photovoltaic dc system in Anhui province. It has being operated for three years safety and steady. The whole application of the system is advanced and groundbreaking in the domestic.