Research on twelve-phase round-shaped transformers applied in rectifier systems

This paper investigates a kind of round-shape transformer for multi-pulse rectifiers in terms of its working principle and design techniques. The transformer discussed is constructed like a blocked wound rotor induction motor. When it works, electric energy is transformed from three-phase input into twelve -phase output. In this paper, the principles of producing 24-pulse output dc voltage and eliminating harmonics of input current were interpreted. Experimental results have exhibited high quality of dc output voltage and clean input current in terms of harmonics when such round-shape transformers were applied into rectifier systems.