Modelling and control of a new DC-side shunt-type nonlinear switching filter

This paper presents the design, modelling, and control of a new DC-side shunt-type, current-source, voltage-hysteresis-controlled, high-frequency switching filter. The concept and principle of operation of the new switching filter are described. System design equations are developed to model the relationship among circuit variables. A multi-loop closed system is proposed to regulate the load current and maintain the switching filter DC link current at fixed level. The salient features of the proposed filter type are the reduced filter power converter rating, reduced size of passive elements, and the elimination of the auxiliary power supply that has been used for the DC link of active filters. System analysis and control design are verified with simulation.