A new harmonic reducing three-phase diode rectifier for high voltage and high power applications

A new harmonic reducing diode rectifier for high voltage and high power applications is proposed. The new rectifier consists of the conventional double sequential (or series connected) three-phase bridge 12-pulse diode rectifier and a particularly designed auxiliary circuit. The double sequential topology is suitable for high voltage and high power applications because the output voltages of the two bridges are added and fed to the load. Harmonics of the utility line currents and ripples of the DC voltage of the proposed rectifier are reduced as low as those of the 24-pulse rectifier due to the operation of the auxiliary circuit. Since the new rectifier does not require any self turn-off device nor controller and the ratings of the components in the auxiliary circuit are also low, the proposed scheme gives an economical, efficient and reliable solution to obtain high voltage and high power DC from the utility without harmonic pollution. In this paper, operation of the new rectifier is introduced, and current and voltage synthesis is then discussed in detail. Experimental results are also shown to confirm the validity of the theory