THREE PHASE AC-DC CONVERTER FOR UTILITY POWER FACTOR IMPROVEMENT AND PEAK VOLTAGE STRESS REDUCTION

Abstract

A three phase, reduced-switch, ac-dc buck-boost type converter that can operate with input-power-factor correction is proposed in this paper. The proposed converter is a simple and low cost topology. The special features of the proposed converter are power factor correction at input side and the peak switch voltage stress is √3 times less than that of the conventional converter. This allows reducing switching losses with lower rated and standard devices that can be used in the converter. The converter is found to be suitable to operate in wide span of output voltages (buck and boost) for an ac input voltage.