Advanced testing of SiC power MOSFET modules for electric motor drives

Abstract

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 onstate 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 onresistance 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.

Online Junction Temperature Estimation of SiC Power <sc>mosfets</sc> Through On-State Voltage Mapping

“…The datasheet does not give any indication about the sensitivity of RON to the current. Other die from different producers were tested, still within custom EMIPAK-2B modules, proving the consistency of the proposed setup and methodology [8]. …”

“…The load current is closed-loop controlled by one leg of the module (LEG2), while the other leg (LEG1) is open loop controlled at a fixed duty-cycle, to mimic a constant voltage load. Details can be found in [8]. The power module is monitored electrically and thermally, as detailed in the next paragraphs.…”

Experimentally validated methodology for real-time temperature cycle tracking in SiC power modules

“…This paper presents the validation of a technique for the indirect junction temperature estimation via on-state voltage measurement, applicable to all types of PWM commanded power converters. This on-line estimation method was proposed in [6]. The junction temperature is estimated at every PWM period by a temperature LOOK-UP TABLE (LUT) whose inputs are the ON voltage and current of the power switch under observation.…”

On-line temperature estimation of SiC power MOSFET modules through on-state resistance mapping

“…12. Other modules were characterized, with SiC MOSFET dies from a different manufacturer, proving the consistency of the proposed setup and methodology [8].…”