An optimized control switching strategy for STATCOM/BESS reactive power output

Abstract

In recent years, STATCOM/BESS (Static Synchronous Compensator/Battery Energy Storage System) has received widespread attention due to its superior power four-quadrant output characteristics. To address the problem of delayed reactive power withdrawal and voltage fluctuations in compensating traditional DC transmission under large disturbances, a fast and effective outer-loop control switching strategy has been proposed. Under small disturbances, a constant bus voltage control method based on PI control is adopted to provide real-time and complete compensation of the receiving end voltage, maintaining the receiving-end bus voltage at the rated value. Under large disturbances, the control mode is switched to open-loop control with constant reactive power, without the delay of the PI loop, enabling timely withdrawal of reactive power upon fault clearance and ensuring stable receiving-end voltage. The proposed control strategy was verified by simulation on the PSCAD/EMTDC platform, demonstrating its feasibility and effectiveness.