Noval hybrid control method for APF based on PI and FRC

The accuracy of control links directly affects the compensation effect of active power filter (APF). Fast repetitive control (FRC) strategy based on single synchronous rotating frame is proposed, for improving the steady-state compensation accuracy and dynamic response. Based on the fundamental rotating mathematical model of APF, the fundamental component of output instruction current can be converted to DC component by synchronous rotation coordinate transformation, and 6k ± 1 times harmonics can be transferred to 6k times harmonics. Then, a hybrid control method based on proportion-integral (PI) control combined with FRC is proposed. The experimental results of the prototype proved that the method advantages in steady-state compensation accuracy, adaptability to load variation and dynamic performance.