A hybrid resonant converter operated as a low harmonic rectifier with and without active control

A 1-φ high-frequency transformer isolated AC-to-DC controlled rectifier with low line current harmonic distortion using a variable frequency controlled hybrid parallel-series resonant converter bridge is proposed. Operation with and without active line current waveshaping is presented. A state space analysis method is used to get various design curves and to predict theoretically the waveforms and line current harmonic distortion. By exercising active current control, power factor close to unity with low line current distortion is maintained for the entire range of operation in addition to zero voltage switching and reduced peak current stresses compared to parallel resonant converter. Simulation results obtained from the state space model, SPICE3 (without active control) and experimental results (rated at 150 W with and without active control) are given to verify the operation of the AC-to-DC converter