Modeling and Control of Current Sensorless PFC Three-Phase Vienna Rectifier with Balanced and Unbalanced DC-link Voltage

In the utilization of three-phase power, the DC-link voltage of the Vienna rectifier can function as two separate voltage sources, accommodating the need for varied output voltages. The voltage-oriented control is usually used to achieve proportional adjustment of the output capacitor voltage, but this typically requires an increased number of sensors. Therefore, this paper proposes a current-sensorless control for a three-phase Vienna rectifier. To reduce circuit volume and cost, the Vienna rectifier topology is analyzed, and a current-sensorless control structure is implemented to minimize circuit volume and cost. Considering the limitation of the single voltage loop in the current-sensorless structure, which affects the output transient response, this paper also proposes a feedforward control architecture. By predicting the steady-state condition of the Vienna circuit in advance, error tracking compensation is performed to improve voltage transient response and compensate for the non-ideal power semiconductor devices. Additionally, integrating the zero-sequence compensation to achieve mitigation of zero-crossing distortion of the input current in power factor correction as well as active balanced and unbalanced output voltage. Finally, through the experimental results of a 2.4 kW Vienna converter, the effectiveness and correctness of the proposed method are validated.