New bidirectional 3-phase PFC reference design speeds up the development of EV charging solutions

With hundreds of millions of electric vehicles (EVs) being deployed in the next two decades, providing a comprehensive charging infrastructure is critical. Equally critical is the efficiency of these charging points.

Supporting this, Toshiba has developed a 3-phase 400 VAC power factor correction (PFC) reference design specifically for EV charging that requires minimal engineering resources to be implemented. This is based on wide-bandgap (WBG) technology and has bidirectional capabilities.

The reference design operates with a near-unity (>0.99) power factor and can deliver a 750 VDC output at 4 kW. The use of a totem pole PFC (TPPFC) design removes the need for a diode bridge rectifier, eliminating the associated losses and allowing efficiencies of 97% to be achieved.

Key to this design’s performance and success is the use of Toshiba’s TW070J120B N-channel silicon carbide (SiC) MOSFET switching device . Three-phase 400 VAC input means the switching elements need the capacity to cope with at least 1000 V. Normally IGBTs would be used, however, they are slower than SiC MOSFETs and have greater switching losses. By using SiC MOSFETs accelerated switching speeds and elevated withstand voltages can be achieved. With a built-in SiC Schottky barrier diode, the TW070J120B has a 1200 V withstand voltage easily meeting the requirement.