Steady state and transient analysis of a three phase current-fed Z-source PWM rectifier

The voltage-source PWM rectifier (VSR) is a boost converter, thus its DC output voltage is much greater than the AC voltage, whereas the current-source PWM rectifier (CSR) is a buck converter and having a DC voltage smaller than its ac voltage. In addition, the CSR can only provide unidirectional power flow, thus unsuitable for regenerative operation. Recently, reverse blocking IGBT (RB-IGBT) has been developed for current-source and matrix converters. In this paper, a current-fed Z-source PWM rectifier is proposed to overcome the limitations of the traditional VSR and CSR. The current-fed Z-source PWM rectifier with only six active switches can buck and boost voltage and provide bidirectional power flow. This paper describes the operating principle of this current-fed Z-source PWM rectifier, presents a detailed steady state analysis and transient analysis. A RB-IGBT based current-fed Z-source PWM rectifier has been developed in laboratory. Both simulation and experimental results are shown to verify the operation and theoretical analysis.