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

In this paper, a deadbeat current controller for a 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 is 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 pulse-width modulation (PWM) control, the proportional-integral (PI) control and the proportional multi-resonant (PMR) for the LC-HAPF, which shows its effectiveness and superior compensating performances.