A Closed-Loop Calculation Control Method for Active Power Decoupling With Minimized-Capacitor Design

Active power decoupling (APD) effectively addresses the issue of suppressing the dc voltage fluctuation in single-phase ac/dc converters. However, it usually uses the closed-loop decoupling capacitor voltage tracking control, which is complex due to the need for designing multiple parameters in the controller. This article proposes a closed-loop calculation control strategy for APD, demonstrated using a buck-type APD circuit. The method employs two resonant filters, with only one parameter to be set, significantly reducing the control complexity. In addition, a circuit parameter design method for achieving the minimum capacitance and zero voltage switching (ZVS) is proposed. This method takes the duty cycle limit into account. When the duty cycle is limited between 0.1 and 0.9, the capacitance is 0.775 times that of the ideal design method. Finally, a 1 kW single-phase totem pole power factor correction (PFC) prototype is constructed to validate results.