A Deadbeat Current Controller of LC-Hybrid Active Power Filter for Power Quality Improvement

In this article, a deadbeat current controller for an LC-coupling hybrid active power filter (LC-HAPF) is proposed, which can track with the reference compensation current with low steady-state error and fast dynamic response. Moreover, it can lead LC-HAPF to be operating at a fixed switching frequency with low output current ripples, thus reducing the size of the filtering circuit. First of all, the mathematical model of the deadbeat current controller for the LC-HAPF is deduced based on its single-phase equivalent circuit. Then, the closed-loop control block diagram and its s-domain model is proposed and built. After that, the stability issue and parameter design of the proposed deadbeat current controller are analyzed and discussed. Finally, the compensating performance of the deadbeat current controller for the LC-HAPF is verified by simulation and experimental results compared with the conventional hysteresis band pulsewidth modulation (PWM) control, the proportional-integral (PI) control, and the proportional multi-resonant (PMR) control for the LC-HAPF, which shows its effectiveness and superior compensating performances.