Three phase current-fed Z-source PWM rectifier

Traditional voltage-source PWM rectifier (VSR) is a boost converter and traditional current-source PWM rectifier (CSR) is a buck converter. A DC-DC converter is requested to use with them to implement buck-boost capability. Also CSR can only provide unidirectional power flow. To overcome these limitations, voltage-fed Z-source PWM rectifier and current-fed Z-source PWM rectifier have been proposed. They can buck and boost the AC voltage with only six active switches. In addition, current-fed Z-source PWM rectifier has its own merits because it can provide bidirectional power flow without replacing the diode in Z network with an active switch which is required in voltage-fed Z-source PWM rectifier. However, CSRs are less investigated because the switches have to be reverse blocking. Recently developed reverse blocking IGBT (RB-IGBT) makes the CSRs and current-fed Z-source rectifiers more attractive and realizable. This paper describes the operating principle of this current-fed Z-source PWM rectifier, analyzes the circuit and characteristics, and discuss the PWM control strategy. 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.