| In the context of rapid development of global photovoltaic(PV) industry and the constant increasing of the installed capacity in the world,the effect of PV output power volatility to grid-connected system can not be ignored. And, how to reduce PV system fluctuation’s influence on grid is a problem that must be solved before more and more large-scale PV power stations have been built. In this paper,a small grid-connected photovoltaic power generation system of 1.5kw is built to study the control strategy of stabilizing the grid-connected PV output power fluctuations.First,the topologies of the common bi-directional DC/DC converter are analyzed and compared and one of the fittest is chosen to study the operating principle.Second,this paper calculates the specific parameters of main circuit element and designs driving circuit,control circuit as well as software of the bi-directional DC/DC converter.Third,based on the adjustment and improvement to the actual operation situation, the preparation of bi-directional DC/DC converter is completed.Then the construction of the experimental platform is completed by researching and designing the other part of forming the energy storage type of grid photovoltaic power generation system,which includes the selection of inverter,power generation process and internal operation mechanism,energy storage battery capacity and charged state, signal detection circuit and a smooth control module circuit, etc..After the comparative analysis on the current application of active power stabilization methods in the wind power and photovoltaic power station,the strategies of anomaly detection method, power fluctuations control, energy storage system of charging and discharging control and bi-directional DC converter control, etc. for the experiment platform are designed.And as reference to the national standard requirement, the control strategy is verified and improved through the practical operation of the system.
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