A Study of a Newly Developed Kelvin-Source Driven SiC-VMOSFET on a High-Power Single-Ended Wireless EV Charger

Recently, Electric Vehicle (EV) is expected to be an effective solution to the environmental problems such as global warming. Realization of compact, lightweight, and low-cost EV charger is the key to wide spread of EVs. An EV charger using a resonant type Wireless Power transfer (WPT) is easy to use, clean, and automatic charging compared with conventional EV charger. Proposed is a low-cost single-ended wireless EV charger using a newly developed SiC-VMOSFET (V-groove trench MOSFET) with an additional Kelvin source connection for improved gate drive. Firstly, a system configuration in the single-ended inverter driven wireless EV charger of compact size and light weight is described. Next, a high power 3kW wireless EV charger with a SiC-VMOSFET of low RON and high withstand voltage is estimated. Then, discussed is a turn off switching loss reduction by a newly developed SiC-VMOSFET with a Kelvin connection and an improved gate drive pattern.