Abstract：Aiming at economic operation in the process of combining energy storage device and PV power generation system,an economic dispatch model has been established according to the analysis of characteristics of PV power generation curve,buying and selling electricity price about PV power generation system. Then based on the economic dispatch model,the running cost of PV power generation system under different capacity of battery is calculated by particle swarm optimization algorithm. And then the comprehensive cost with battery is got. Also the best capacity of the battery is determined according to the comprehensive cost. The simulation analysis shows that the reasonable choice of battery capacity not only smooth PV battery output,but also improve the economic operation of PV power generation systems obviously. And it will strengthen the effect of peak load shifting.

Keyword：grid-connected photovoltaic;energy storage device;economic dispatch;the choice of capacity,the particle swarm;