A Fast and Accurate GaN Power Transistor Model and Its Application for Electric Vehicle

Abstract

In order to overcome the challenge of balancing accuracy with simulation speed of power electronics converters for system-level simulation, the paper proposes a GaN power transistor model that can accurately and rapidly predict power losses, which is suitable for system-level application such as an electric vehicle. The model is based on equivalent circuit and formed by behavioural equations to carefully model both conduction and switching losses. As a novelty, transistor power losses due to dynamic ON-state resistance is also included in the model. By comparison with experimental measurements and other available models of the similar type from the literature, it is shown that our model gives accurate results of the power losses and it helps to reduce the error by more than 70%. To accelerate simulation speed, power loss calculation and simulation time-step is decoupled. The power losses are represented in different levels and in the form of mathematical equations and look-up tables in MATLAB/Simulink. It is shown that our approach is able to reduce the simulation time by almost 18 times and maintain the same accuracy. The proposed GaN transistor loss model is finally implemented into a racing vehicle powertrain, where designers can obtain the power losses and temperature of the used power transistors in an easy and rapid way to optimise power electronics design.