Modelling and design of a reversiblethree-phase switching mode rectifier

A reversible three-phase switching mode rectifier consisting of a four-active-switch and without current sensor is proposed. To achieve controllable power factor, clean sinusoidal input current, adjustable DC output voltage, and bidirectional power flow capability, a closed-form pulse width modulation (PWM) duty cycle function is derived. The popularly used state space averaging technique is extended for modelling the reversible three-phase four-active-switch rectifier. The space vector representation technique is then used to simplify the modelling process without sacrificing accuracy and valid frequency range. Both steady-state and small signal analyses are made. Results show that the proposed closed-form control law for the rectifier can indeed achieve the desired property. Moreover, the rectifier also possesses a bidirectional power flow capability, which is useful for many applications. Finally, a prototype hardware circuit was constructed and experimental results are presented for demonstration. Guidelines for determining the LC parameters and the PI controller gains are described briefly in the text.