Current decoupling control of STATCOM combined with battery energy storage system

FACTS devices can expand operating range, improve performance, expand functionality, and make power transmission more flexible if it is combined with energy storage system. Due to the disadvantage of traditional STATCOM for only regulating reactive power, a STATCOM combined with battery energy storage system is proposed, which can achieve dual regulation of reactive power and active power or so called four-quadrant compensation to the system, meanwhile the DC voltage is almost constant, and need not to be controlled. The operating principle of STATCOM/BESS is described, and a mathematical model is derived. For the realization of independent regulation of reactive power and active power, the current decoupling control method based on rotating frame is adopted, and the setting principle of PI parameters is presented. Simulation and experimental results show that using this control method STATCOM/BESS can achieve good dynamic and steady-state characteristics, and have theoretical value and practical significance.