Toshiba's reference design of a power factor correction (PFC) circuit for 3-phase 400 VAC inputs illustrates how to improve power supply efficiency using SiC MOSFETs. The design achieves a power conversion efficiency of 97 % and a power factor of 0.99 or more. It is a reference design for the PFC section which includes a gate drive circuit, sensor circuit and output power switch of high-power converters such as electric vehicle (EV) charging stations.
The growing adoption of EVs has increased the demand for power conversion systems that must also be highly efficient and compact. This Toshiba reference design provides an excellent starting point for the PFC stage of power converters. It can be used as the basis for both prototyping and developing your application, helping it reach its full potential.
Here is an example application that uses this reference design. It is a system that permits bidirectional charging by converting 3-phase 400 VAC to DC with a high efficiency PFC power supply and combining it with bidirectional DC-DC converter(introduced in the following article).
The use of three-phase 400 VAC as input power requires a power factor corrected (PFC) power source for AC-DC conversion plus a highly efficient insulated DC-DC conversion mechanism for supplying power to the EV battery charging circuit from the DC output of PFC with minimal losses. Furthermore, if there needs to be scope for the EV battery to potentially be used as a power source for other tasks, then bidirectional DC-DC converters will clearly prove useful.
This application example intends to promote the widespread use of high-speed, low loss EV charging stations. It does this through the combination of PFC power supplies, for efficient AC-DC conversion of high power from three-phase 400 VAC, plus insulated DC-DC converters that ensure both elevated efficiency and bidirectional operation.