SEPIC derived three-phase switching mode rectifier with sinusoidal input current

A SEPIC derived three-phase rectifier is proposed to achieve clean sinusoidal input current, unity power factor, step up/down DC voltage and to be insensitive to input voltage distortion. Depending upon how many boost modes are chosen and which class of generalised zero voltage space vector is selected to obtain the equivalent DC duty cycle, different control strategies can be obtained. It is seen that through introduction of an equivalent duty cycle, the DC/DC SEPIC converter function can be maintained without affecting the desired rectifier characteristic. The input to output voltage gain for two control strategies is also derived. Finally, a hardware implementation example and some experimental results are given to demonstrate the validity of the proposed rectifier.