Performance and Design Analysis on Round-Shaped Transformers Applied in Rectifier Systems

In this paper, a novel rectifier transformer that has a round-shaped structure is investigated. The transformer can convert three-phase power into 12-phase, which supplies to a rectifier composed by four bridges for producing dc voltage with 24-pulse. With such transformers, rectifier performance can be improved in both input and output waveforms. The principle of harmonics elimination is explained and some critical problems may be encountered in design are discussed. The experiments on the prototype are carried out for performance assessments regarding characteristics, such as ripple factor, total harmonic distortion, efficiency, etc. The results demonstrated the effectiveness of the novel transformer in harmonics mitigation.