Inrush Current Limiting of a Bridgeless AC- DC Converter

A simple inrush current limiting technique is presented here for hybrid resonant Pulse-Width Modulation bridgeless AC - DC power factor correction converter used in power supplies and battery charging units. The DC bus capacitor voltage is gradually increased to limit the charging current. As boost converter is not operated at high duty cycle, the PWM switch for gradual increase in voltage is incorporated with other PWM switches. The method used here is designed for the boost type converter but can be implemented on other type of converters as well. The technique also reduces spikes in current wave forms of traditional bridgeless AC-DC converters. The simulation is performed in MATLAB/SIMULINK. A comparison is also provided to show the effectiveness of the system.