Maximizing Cost-Efficiency in Electric Drivetrains: A SiC/Si Fusion Switch Approach

Abstract:
In order to further drive electrification of cars, there is a critical need to optimize cost-efficiency in electric drivetrain components. This paper investigates the potential of integrating silicon insulated-gate bipolar transistors (IGBTs) and diodes with silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs) in parallel configuration to address this imperative. The hybrid concept emerges from the fact that SiC, while offering improved light load efficiency, is more expensive due to higher manufacturing complexity and energy demand, while silicon IGBTs have cost-efficient high load capability. The focus of this research is set on ease of use, i.e. only one gate pin is used. To aid the optimization of this fusion drivetrain, analytical equations for the inverter losses are presented and used for analyzing cost-performance in the Worldwide Harmonized Light Vehicles Test Cycle (WLTC). A HybridPACK(TM) Drive G2 Fusion prototype is built up and measurements on static and dynamic performance are pre-sented, revealing a good match of Infineon’s CoolSiC(TM) and EDT3 chip technology for parallel operation.