A Concise Analytical Datasheet-Driven Turn-Off Overvoltage Prediction Method for SiC MOSFET Based on Accurate Overvoltage Timing Estimation

An analytical datasheet-driven turn-off overvoltage prediction method is proposed in this paper. Firstly, a linearly simplified turn-off transition model distinguishing overvoltage point from the end of the turn-off transient is presented. Additionally, a concise expression for turn-off overvoltage prediction is derived based on accurate overvoltage timing estimation. Moreover, the processes of parameters extraction and calibration are also illustrated. Notably, all parameters utilized in the proposed prediction method are entirely extracted and calibrated from the datasheets without any other measurements, which means it is fast and low-cost. Subsequently, five different SiC MOSFETs are packaged in N-cell phase-leg modules, and a double pulse test (DPT) platform is established to verify the proposed prediction method under a wide range of operating conditions. Experimental results indicate that the proposed turn-off overvoltage prediction method is accurate in most operating conditions. Finally, the errors are analyzed and the applicability range of the proposed prediction method is discussed.