Operation of the LCC-type parallel resonant converter as a low harmonic rectifier

A single-phase high-frequency transformer isolated single-stage AC-to-DC controlled rectifier with low line current harmonic distortion using a variable-frequency controlled LCC-type (or series-parallel) resonant power converter (SPRC) is presented. A simple analysis and design procedure is used for designing the converter for low line current harmonic distortion and high power factor operation. The converter performance characteristics have been verified with SPICE3 simulations (without active control) and experimental prototype SPRC (rated at 150 W, with and without active control) for variation in load as well as line voltage. When operated with active current shaping, this converter operates in zero-voltage-switching mode for the complete range, maintaining power factor close to unity with low line current distortion and low peak current compared to the parallel resonant converter.