Design of DC-bus voltage controller for HAPF using low-pass filter

The DC voltage control for Hybrid Active Power Filter (HAPF) is critical for the safe and operation performance especially during the dynamic process. Traditional controller, e.g. P or PI, has some shortcomings in the control of DC-bus voltage, including steady error and complicated optimizing design, especially not good enough dynamic performance in the HAPF application. In this paper, a second-order low-pass filter is put forward to act as a novel controller according to the small signal model DC-bus voltage regulation, which is based on the detailed analysis on the balance of the active power of the active part in HAPF. Compared with PI controller, the new controller can obtain better dynamic performance as load or grid voltage change, and simulation verifies the feasibility and validity of the proposed control strategy.