GaN-based Resonant Energy Transfer System for EV-Drives with Electrical Excitation

This paper presents a contactless energy transfer system for supplying the rotor of an electrically excited synchronous machine using gallium nitride as a wide-bandgap semiconductor material. Due to the requirements for maximum efficiency, a resonant LLC circuit topology is used. The design of the rotating high-frequency transformer with regard to optimal switching of the GaN semiconductors and the corresponding effects on the resonant circuit are discussed in detail in the paper. The operating behavior is evaluated by simulation and measurement of a test arrangement.