Fusion switch concept addresses the cost-performance dilemma in EV powertrains

Abstract:
This paper introduces a simplified approach for a parallel operation of Si IGBTs and SiC MOSFETs in an automotive traction inverter. The so called “Fusion switch” thereby uses one common gate driver and therefore simultaneous switching. In order to achieve a safe but near efficiency optimal operation special requirements have to be fulfilled by the devices to enable this ease of use. The theoretic idea behind this concept is validated in this paper by measurements using well matched EDT3 IGBT/Diode chips with CoolSiC(TM) SiC MOSFETs in a HybridPACK(TM) Drive prototype power module. Double pulse meas-urements confirm the ultra-high switching speed with smooth switching transients. Inverter thermal IR testing demonstrates the pursued current sharing in both, light and full load, inverter operation condi-tions. Finally, inverter calorimetric tests in comparison to state-of-the-art solutions verify the power loss reduction provided by this Fusion concept in the typical WLTP and CLTC-P drive cycle relevant opera-tion area.