Characteristics of fixed-frequency hybrid resonant converter operating on the utility line

A single-phase single-stage AC-to-DC controlled rectifier using a high-frequency transformer isolated hybrid parallel series resonant converter bridge, operating on the utility line, is described. A fixed-frequency phase-shift control scheme is used to achieve high line power factor with reduced line current harmonic distortion. Based on both approximate AC and state-space analysis, design curves are obtained. A design example for a 150 W converter is presented. The converter performance is evaluated with SPICE simulation (without active control) and by measurements on the 150 W broadband model. The line power factor is greater than 0.95 with harmonic distortion of 16.5% (at full load), even without active control. A simple active line current control technique has been used for waveshaping the line current waveform close to sinusoid, and to reduce the line current total harmonic distortion