In this paper, a new discontinuous pulse width modulation strategy based on circuit-level decoupling concept (CLD-DPWM) has been proposed for Vienna rectifier. In this method, Vienna rectifier is decoupled into two 2-level boost converters which lead to considerable reduction in the controller complexity. Moreover, due to the inherent capability of balancing the capacitors voltages, requirement for an extra feedback loop and sensor is avoided. Additionally, the proposed strategy mitigates switching loss compared with conventional continuous PWM methods. The validity of the proposed CLD-DPWM technique has been investigated via simulation and experimental verification, conducted on a 1 kW Vienna rectifier and a 250 W laboratory prototype, respectively. Based on the simulation and experimental results, using the proposed control technique, unity power factor and low current THD along with balanced capacitor voltages are well achieved.

Keywords: Vienna rectifier, Discontinuous pulse wide modulation (PWM), Circuit-level decoupling, Current total harmonic distortion (THD), Neutral point balancing