HARMONIC REDUCTION IN SINGLE-PHASE DIODE RECTIFIER CIRCUITS USING A SWITCH-CONTROLLED INDUCTOR

Abstract

A novel design principle of a low-distorted single-phase rectifier using, instead of a time-variable transformer, an appropriate time-variable inductor is proposed and analyzed. Such a rectifier circuit contains a diode bridge, a switch-controlled current-shaping inductor, and a time-invariant smoothing capacitor. From the point of view of energy flow, the distortion reduction is based on the improvement of energy transfer and exchange processes. In the proposed circuit, the switch-controlled inductor realizes an appropriate controlled current source converting the active power of the second and other even harmonics into direct-current power. To implement the ideal undistorted rectification, continuous inductance variation is needed. Nevertheless, the suitable stepped variation of inductance enables us to synthesize diode rectifiers with the high power factor even using only the simplest diode switches.