Design of DC-bus voltage controller for Hybrid Active Power Filter based on pole-zero placement

The DC-bus voltage self-regulating of Hybrid Active Power Filter (HAPF) is not only critical to compensation performance, but also to the safe operation. Traditional controller, e.g. P or PI, has disadvantages for these applications. Regarding the popular shunt HAPF with passive and active filters in serial connected, this paper presents a novel controller for the DC-bus voltage self-maintaining. The control model based on equilibrium of instantaneous power theory is established, simplified and analyzed in details, and then the pole-zero placement method is adopted to design the novel controller. Compared to PI controller, it can improve dynamic performance greatly as load and/or grid voltage changes. The feasibility and validity of the DC-bus voltage controller is verified through a prototype design using MATLAB/Simulink.