Hybrid power control of cascaded STATCOM/BESS for wind farm integration

Static synchronous compensator combined with battery energy storage system-STATCOM/BESS, can regulate four-quadrant active and reactive power, which is an ideal scheme to solve problems of wind farm integration. Multilevel converter is the key technology for STATCOM/BESS. The advantages of cascaded multilevel converter are analyzed and the structure of cascaded STATCOM/BESS is described. Hybrid power control strategy is proposed to compensate active and reactive power of wind farm comprehensively. The reference current of STATCOM/BESS is determined according to the requirements of active power smoothness and voltage control. The control strategy can coordinate charge or discharge of batteries with reactive power compensation of STATCOM, and balance the batteries capacity of H-bridges. The proposed control strategy is validated by simulation on the wind power system using cascaded STATCOM/BESS as the compensation device. Simulation results show that the cascaded STATCOM/BESS can effectively improve the characteristics of wind farm integration and provide dynamic support to the grid.