N-level GaN Transistor Model for Fast Simulation of Electric Vehicle based Power Electronics Systems

Accurate and fast power loss estimation models based on a good understanding of the occuring loss mechanisms are crucial to achieve high efficiency, high power density and to take full advantage of the superior characteristics of Gallium Nitride (GaN) devices compared to silicon (Si) devices. In this article, a N-level GaN model for loss calculation of a half-bridge circuit with inductive or resistive-inductive load focussed on high simulation speed is presented. Therefore, a novel method, combining an efficient simulation structure with a finely fractioned and accurate power loss calculation, is used. A detailed analysis of GaN loss mechanisms including static-, dynamic-$R_{\mathrm{dson}}$ and deadtime conduction loss as well as switching loss for different types of switching transitions is conducted. Following, the model, in which circuit simulation and loss calculation are uncoupled in order to reduce the computational costs while remaining the accuracy with respect to the manufacturer Spice model, is presented. The loss calculation part of the model includes mathematical, physical and look-up table based sub-models. The model is finally validated by comparing it to the manufacturer Spice model. By using the proposed model, computational costs are reduced by more than 92% at an error of less than 2% in comparison to the same simulation performed with the manufacturer Spice model.