Electronic phase shifting in multipulse rectifier

Abstract

This paper presents a novel converter which can reduce the harmonics like the conventional multipulse converters with input three phase transformer. To reduce total harmonic distortion of input current and improve the weight and size of converters, it is suggested to use multi-pulse rectifiers with an electronic phase shift. The basic module is a 6-pulse rectifier on fully controlled switches with the reverse blocking ability. Switching frequency either coincides or is twice the power frequency. The proposed solutions allow refusing from the electromagnetic phase-shifting devices (power transformers or auto-transformers) and thereby significantly reduce the weight of the device. Unlike power factor correction systems with high-frequency modulation, the proposed converters are significantly different, as they have better electromagnetic compatibility and the virtual absence of dynamic switching losses of power switches.