A new series‐connected 36‐pulse rectifier with hybrid DC‐reinjection method for high power output

Abstract

AbstractIn this study, a new 36‐pulse rectifier with a hybrid DC‐reinjection circuit is proposed. It multiplies the AC‐side input voltage steps from 12 to 36 using a hybrid auxiliary circuit for voltage and current modulation. Both the AC and DC side harmonics of the rectifier system are efficiently suppressed when combined with filter capacitors at DC side. Only 2 more diodes and an IGBT are used in the proposed approach for constituting the injection circuit. The cascaded structure of rectifier bridges allows for significant voltage gain, making it appropriate for high power output rectification applications. The proposed 12‐pulse rectifier's phase shifting structure and 36‐pulse rectifier's operational theory are introduced. The injection transformer's turn ratio and the IGBT's conduction angle are both designed to have the lowest possible harmonic distortion of the voltage at AC side. Analyses are done on the rectifier's impedance matching feature and energy loss of IGBT. The operating performance of the rectifier is assessed when the active switch fails. With the help of a 1.8 kW prototype and a HIL system based on Starsim, the theoretical portion is confirmed. The results of the simulation and experiments support the effectiveness of the hybrid voltage harmonic injection method studied.