A Simple 24-Pulse Rectifier Combing Isolated Y-type Transformer and Current Injection Circuit

In this article, a simple 24-pulse rectifier using isolated Y-type phase-shifting transformer and current injection circuit is proposed. The current injection circuit includes inter-phase reactor(IPR), auxiliary single-phase transformer (AST), and an auxiliary single-phase full-bridge rectifier (ASFR). By the modulation of IPR and AST, the input current of the rectifier is changed, the three operating modes of the structure are constituted. The pulse number of the input current is doubled to 24 pulses, so that the input current harmonics and output voltage ripple are significantly suppressed. By designing the optimal turn ratio between IPR and AST, the theoretical input line current total harmonic distortion(THD) is reduced by half. The simulation results are presented to validate the theoretical analysis.