A 36-pulse Single Transistor, Hybrid Ripple Injector for Aerospace Rectifiers

A hybrid ripple injection circuit to improve the power quality of a typical 12-pulse autotransformer rectifier for aerospace applications is presented in this paper. This injection circuit enhances the performance of the 12-pulse rectifier bestowing line current waveforms of a 36-pulse. It consists of a low-rated Vienna rectifier leg and an injector transformer. The proper operation of the Vienna rectifier transistor causes the transformer injector to modify the voltages in the main rectifier to improve the rectifier performance. The injector current rating is 2.2% of the output current. The hybrid ripple injector and rectifier principle of operation are described throughout this paper together with experimental results obtained with a 4-kW prototype.