A Three-phase Power-factor Correction Scheme Using an Autotransformer and Two Single-phase Buck Rectifiers

Abstract

This paper presents a three-phase unidirectional rectifier with power-factor correction (PFC) using two modified single-phase Buck rectifiers in continuous conduction mode (CCM). The phase reduction technique using an autotransformer based on Scott Connection renders a non-isolated rectifier to operate with unity power factor. The power of autotransformer is only 14% of the total output power. Two single-phase buck rectifiers interleaved are able to regulate low voltage output. The control system is simple and it has only one voltage control loop. Theoretical analysis, design procedure and complete simulation results with closed loop operation are given. A 4-kW prototype has also been implemented in the laboratory which demonstrated to operate successfully with excellent performance.

Keywords

• buck rectifier
• AC-DC converters
• PFC converters
• Scott Autotransformer
• sinusoidal pulse width modulated