Multi-Objective Design Optimization of SiC-Based Electric Vehicle Drive-train Inverter

Silicon Carbide (SiC) MOSFETs are used in state-of-the-art drive-train inverter designs for electrical vehicle (EV). Due to a lack of comprehensive multi-objective inverter design framework, such inverters designed through trials would result in sub-optimal designs. The optimal inverter design framework proposed in this paper, involves the objectives of maximizing efficiency $(\eta)$ and power density $(\rho)$. An analytical approach based algorithm is used to simulate the total power loss and volume parameters required to calculate $\eta$ and $\rho$ respectively, and iterated over two loops: (i) across a range of switching frequency $(\gamma_{sw})$ to plot the $\eta-p$ pareto curve and find the optimal designs of one SiC device category, (ii) across different SiC device categories (having various blocking voltages, $V_{b}$) to plot all $\eta-\rho$ pareto curves in different categories of inverter design, and finally store as optimal design datasets. The datasets will be analyzed to identify the globally $\eta-p$ optimal inverter design with superior $\eta-\rho$ performance and corresponding $V_{b}$ and operating $f_{sw}$. The global-optimal designs for both 300 kW and 80 kW drive-train inverters involve utilizing the 1200 V half-bridge module at $f_{sw}$ of 40 kHz and 35 kHz respectively.