Power conversion system

1. A power conversion system comprising:

a filter unit;

a multi-phase DC/DC converter for boosting DC voltage of a DC source and electrically coupled to the DC source through the filter unit, the DC/DC converter comprising a plurality of silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs) configured in a synchronous rectification mode by channel reverse conduction control, wherein a positive gate drive signal applied to a gate terminal of the plurality of SiC MOSFETs that are reverse channel conducted from a source terminal to a drain terminal enables current to pass through a less-loss channel of the plurality of SiC MOSFETs;

a DC link;

an inverter for converting the boosted DC voltage from the DC/DC converter to multi-phase AC voltage through the DC link to drive an AC driven device; and

a control unit for providing pulse-width modulation (PWM) commands to the DC/DC converter and the inverter, wherein the commands for the DC/DC converter and inverter have the same frequency.

2. The power conversion system of claim 1 , wherein the inverter comprises a plurality of SiC MOSFETs configured in a synchronous rectification mode by channel reverse conduction control.

3. The power conversion system of claim 1 , wherein the inverter is a multi-phase inverter.

4. The power conversion system of claim 1 , wherein the filter unit comprises a plurality of magnetically coupled inductors.

5. The power conversion system of claim 4 , wherein the plurality of magnetically coupled inductors comprises a shared magnetic core and a plurality of coils wound on the shared magnetic core.

6. The power conversion system of claim 5 , wherein the shared magnetic core comprises a plurality of parallel magnetic columns electrically coupled together, the plurality of coils are respectively wound on the plurality of parallel magnetic columns.

7. The power conversion system of claim 5 , wherein the shared magnetic core is ring-shaped and the plurality of coils are respectively wound evenly on three different parts of the ring-shaped magnetic core.

8. The power conversion system of claim 7 , wherein the turn ratio of the plurality of coils is 1.

9. The power conversion system of claim 1 , wherein the control unit comprises:

a difference element for obtaining a DC voltage error signal calculated from a difference between a feedback DC voltage signal on the DC link and a predetermined DC voltage command signal; wherein the predetermined DC voltage command signal comprises an active pulsation DC voltage signal, and the frequency of the pulsation DC voltage signal matches with the frequency of the AC voltage signal to be converted by the inverter; and

a PWM command generation block for generating PWM commands according to the DC voltage error signal.

10. The power conversion system of claim 9 , wherein the predetermined DC voltage command signal comprises a sinusoidal wave signal.

11. The power conversion system of claim 9 , wherein the DC link comprises a capacitor.

12. The power conversion system of claim 9 , wherein the filter unit comprises a plurality of magnetically coupled inductors.

13. The power conversion system of claim 1 , wherein the DC source comprises a battery and the AC driven device comprises a traction motor applied in an electric vehicle.