For improving grid-connection operation ability of wind farm

provision of DC power transmission grid-connection topological structure of wind-thermal bundled power system and battery energy storage system（BESS）combined with static synchronous compensator（STATCOM）at the input end is proposed. The control strategy with aim of maintaining busbar voltage stability of the input end is designed.In case of frequent fluctuation of wind velocity at the output end

the unfavorable influence due to wind velocity fluctuation can be weakened by the thermal power plant to maintain voltage stability from the input to the receiving end. In case of abrupt variation of grid load/three-phase short circuit at the receiving end

the BESS-STATCOM can assure fast recovery of grid after interference

provide a definite active support at the same of compensating reactive power to the system and overcome the unfavorable influence to the system due to sudden load variation. The effectiveness of the proposed simulation scheme is shown.The BESS-STATCOM can make the wind farm pass through fault and the operation condition is basically not influenced by the fault that the receiving end of the grid.