Robustness Analysis of Temperature-Sensitive Electrical Parameters of SiC MOSFETs

Temperature-sensitive electrical parameters (TSEPs) show great potential for high-bandwidth online junction-temperature estimation of silicon carbide (SiC) power MOSFETs. However, the sensitivity of TSEPs to parasitic influences, such as dc-link voltage, load current, and gate supply voltages, complicates their practical implementation. These influences are often ignored and previous studies have primarily concentrated on individual parameters or on insulated-gate bipolar transistors (IGBTs). Therefore, we assess various TSEPs for SiC MOSFETs using double-pulse and curve-tracer measurements, evaluating their robustness against these parasitic influences. For this assessment, a novel metric is introduced to compare TSEPs and their respective sensitivities to these parasitic influences. This metric enables the influences’ compensation through calibration and can be used to identify parameters for potential sensor fusion concepts to enhance robustness.