Switching Ripple Current Reduction of DC-Link Capacitor in a Two-Stage Single-Phase AC/DC Converter

Abstract

In this paper, a control method for reducing the switching ripple currents flowing to a DC-link capacitor in a two-stage single-phase charger is presented. The switching sequences of both converter circuits are addressed by applying triangular and saw-tooth carrier waveforms in order to reduce the switching ripple current of the DC capacitor. Moreover, a sampling method of the current that is suitable for application in the control procedure is proposed. The proposed method varies the sampling frequency and points according to the input and output voltage conditions. The reduction effect of the switching ripple current is confirmed by analysis and the results of an experiment in which a DC-DC converter with power factor correction was used under the conditions of a source voltage 100V and an output power 1 kW.