Double Pulse Test Platform for Hybrid SiC-IGBT Switch Characterization and Optimal Gate Control Strategy for EV Traction Inverters

This paper evaluates the performance of a hybrid switch for Electric Vehicle (EV) traction inverters using a specialized Double Pulse Test Platform (DPTP) and automated characterization procedure. The Hybrid Switch is composed of Silicon (Si) Insulated Gate Bipolar Transistors (IGBTs) and Silicon Carbide (SiC) Power MOSFETs connected in parallel.The SiC/IGBT solution improves low-current performance due to its unique ON state characteristics and superior switching performance, which has garnered increasing interest from car manufacturers. By selecting the appropriate number of devices or silicon dice in parallel, the hybrid switch can achieve lower switching losses compared to an IGBT-based solution. However, the optimal selection of SiC and IGBT properties and gate control strategy is crucial. The hybrid switch requires precise experimental testing of the delay time between the turn-on and turn-off of SiC and IGBTs, which is time-consuming if done manually.This paper introduces an automated method using a DPTP that significantly reduces the characterization time. Three inverter switch configurations are compared: a discrete hybrid switch with 4 parallel devices (1 SiC and 3 IGBTs) in a T-PAK package with a similar current rating, a full SiC solution, and a full IGBT solution with four devices in parallel in the same package. Experimental results demonstrate the benefits of the Si/SiC hybrid switch for EVs, and an optimal control strategy is proposed based on the selected hybrid switch configuration.