GaN on silicon E-HEMT and pure silicon MOSFET in high frequency switching of EV DC/DC converter: A comparative study in a nissan leaf

This paper presents the merits of using low-losses fast-switching, Gallium Nitride on Silicon Enhanced mode High-Electron-Mobility-Transistor cascode switches; in comparison to pure Silicon MOSFET in the DC/DC converter of the Nissan Leaf electric vehicle (EV). The performance of the car, at steady state conditions, is studied to show the technical benefits of using Gallium Nitride on Silicon Enhanced mode High-Electron-Mobility-Transistor cascode as the switching device. This device belongs to a 600 V power semiconductor devices family of high density wide band gap. It achieves extremely efficient power conversion with fast switching slew rates higher than 150 V/ns compared to 50 V/ns for the pure silicon. Moreover, it has low reverse recovery charge that reduces the switch loss significantly compared to its peers of pure silicon. To assess these merits, an EV powertrain model was simulated in PSIM. This model considers the calculation of both switching and conduction losses for each material. The power losses and efficiencies were observed for different junction temperatures. The results showed lower total switches power losses with the GaN switch. This reduction in losses was recorded at different switching frequencies.