Single-Phase Resonant Converter with Active Power Filter

A single-phase AC-to-DC converter using modified series-parallel resonant converter (MSPRC) in conjunction with active power filter (APF) is presented for improvement of power factor on input AC line. The pulsating DC voltage obtained from the single phase uncontrolled diode bridge rectifier is applied to high frequency full bridge configuration of the MSPRC. For high power factor operation small active power filter is used. Analysis and design of converter for low current harmonic distortion and high power factor operation is given. An APF consists of pulse width modulated (PWM) voltage source inverter that is operated in variable switching frequency mode. The operation of the converter with and without active control is presented. The output voltage of the converter is regulated independently by using variable frequency control and duty ratio control. The MSPRC operates on lagging power factor mode for the entire load range to maintain the zero-voltage switching. The design procedure of the converter is outline in detail. The converter is simulated using MATLAB (Simulink). To validate the simulated performance an experimental (10 kW) prototype of single-phase AC-to-DC resonant converter is built using high frequency devices, MOSFETs. Experimental results show the high power factor operation of the converter through out the load range.