Mobile QR Code QR CODE : The Korean Institute of Power Electronics
Title Feed-Forward Compensation Technique in Stationary Reference Frame for the Enhanced Disturbance Rejection Performance in Parallel Operation of Double-Conversion UPSs
Authors Hyo-Jun Ryu ; Young-Doo Yoo ; Jae-Sung Mo ; Seung-Cheol Choi ; Tae-Gyeom Woo
Page pp.367-375
ISSN 1229-2214
Keywords Grid-connected inverter; LCL filter; Stabilization; Digital notch filter
Abstract Generally, a proportional-resonant controller is used to eliminate steady-state errors during the voltage? current control of a double-conversion uninterruptible power supply (UPS) in a stationary reference frame.
Additionally, the feed-forward control compensating for the load current, which can be considered a disturbance of the voltage controller, can be used to improve the disturbance rejection performance. However, during the parallel operation of UPSs, circulating current can occur between UPS modules when performing both feed-forward control and droop control because feed-forward control reduces the circulating current impedance. This study proposes a feed-forward compensation technique that considers the impedance of circulating current. An additional feed-forward compensation technique is developed to enhance the disturbance rejection performance. The validity of the proposed feed-forward compensation technique is verified by the experiment results of the parallel operation of a 500 W double-conversion UPS module.