Improved Methodology for Estimating Switching Losses of Wide Band-Gap Semiconductors Using Gaussian Curve Fitting

The accurate assessment of switching losses is critical for evaluating the achievable performance of hard-switched applications implemented with wide band-gap semiconductors. The traditional method for evaluating the switching losses for a particular semiconductor device is to calculate the instantaneous switching power from the drain-source voltage and drain current waveforms, and then integrate the power waveform to compute switching loss. However, a potential problem arises due to the need to manually select limits of integration for the resulting instantaneous power waveform. To date, there is no widely recognized standard practice for selecting integration bounds during this process. The resulting variability in approach compromises the ability to fairly assess and reliably compare performance between devices. To address this issue, the present paper proposes a switching loss estimation method based on Gaussian curve fitting that does not rely on human judgment. The details of the proposed method are discussed, and the results using this method are compared to those from the traditional limit selection method. As is shown, this approach is simple and straightforward to implement, produces consistent results across a wide range of operating conditions, and is especially suitable for automated post-processing of switching waveforms.