Inductive Power Transfer for Electric Vehicles Using Gallium Nitride Power Transistors

Abstract

This chapter will present the application of the GaN Gate Injection Transistor (GIT) in Inductive Power Transfer (IPT) for Electric Vehicles (EV). IPT provides significant benefits over conventional plug-in chargers but suffers from lower efficiency. A high frequency inverter using GaN GIT, which has low on-resistance and gate charge, is implemented to reduce switching and conduction loss, resulting in higher efficiency. Different gate drive strategies will be compared for driving the GaN GIT at high slew rates while ensuring cross-conduction protection. The switching characteristics of the GaN GIT are studied and the inverter is designed to ensure low switching losses, while keeping overshoot and slew rates under control. Experiment results presented will demonstrate that the system efficiency peaks at 95% at 100 kHz operation and 92% at 250 kHz operation for a coil gap of 80 mm at 2 kW output power.Inductive Power Transfer for Electric Vehicles Using Gallium Nitride Power Transistors http://dx.doi.org/10.5772/intechopen.76057 125 Half bridge circuit loss modelingThe total losses in a half bridge circuit contains conduction loss, switching loss, ringing loss and dead time loss of the top and bottom power device and is shown in Eq.(3). The subscript top and bot respectively denote the top and bottom power device.