Advanced testing of SiC power MOSFET modules for electric motor drives

SiC power MOSFETs are an advancement in the power electronics technology today available on the market. Respect to Si-based power devices, they offer potential for higher operating temperatures, higher breakdown voltage with low on-state resistance, and lower switching losses permitting much higher switching frequencies. To date, the attempts to apply the SiC power devices to the field of AC drives are relented by the high price of such new devices and by the challenges related to electromagnetic compatibility and reliability. A new test rig is proposed, built for comprehensively testing SiC power MOSFET modules in real operating conditions, using off-the-shelf hardware. The presented results focus on the evaluation of on-resistance as a function of drain current and junction temperature, and on dv/dt evaluation as a function of external gate resistance. Different modules are tested, custom realized using SiC MOSFET dies by two leading manufacturers. Finally, a new methodology for on-line estimation of the devices junction temperature is presented.