Novel three-phase AC-AC soft-switching series-resonant converter topology with six switches

Abstract

Three-phase AC-AC series-resonant converters using pulse modulation with internal frequencies of 10 kHz, and suitable for multi-kilowatt power levels, have the excellent characteristics of generating multi-phase bipolar waveforms with reversible power flow, low distortion and fast system response.This proposal presents a novel converter topology with only six switches. The switch current is a half period of the sine wave as generated by the resonant network. The ai/at is limited during the switching interval. The switching loss equals the produkt of switch voltage and switch current is consequently low. The principle of soft-switching can reduce the total power losses by one third to one half compared to the previous series-resonant converter without soft-switching (2).The converter controls the output voltages as well as the input current. The harmonic distortion of both waveforms is low. The power factor of the input currents is controlled.

A multiphase series-resonant converter with a new topology and a reduced number of thyristors

“…This conclusion was confirmed by a simulation of this system: although the output currents conformed reasonably well to their prescribed (sine) wave shapes, the input currents showed a ragged appearance. A similar result has been reported in [14].…”