Considering the intermittent property of photovoltaic generation,the battery energy storage system combined with hydrogen generator were used to adjust the grid connected power for improving the stability of photovoltaic grid connected operation.The hydrogen generator was installed in photovoltaic generation system to generate high purity hydrogen.The photovoltaic generation system including energy storage unit were modeled and simulated using PSCAD/EMTDC.The simulation results verify that the battery energy storage system adopting four quadrant converter control is able to quickly smooth the fluctuation of active power output of photovoltaic generation system.