S16 - Determining Switching and Conduction Loss in Si, SiC, and GaN

One of the key challenges facing power electronic engineers is how to determine what the losses will be in their converter circuit, in order to compare and assess various topology and control options, without having to actually build and test all of them. This topic is increasingly relevant as conversion efficiency continues to rise into the mid and even upper 90% range. Rough calculations are no longer good enough, as every watt needs to be accounted for and understood. This seminar focuses on the switching power transistors, particularly the high-voltage devices in the 400 – 1200 V range used in many applications today. Designers expect that they can enter a schematic into a simulation environment, and get an accurate result easily. But the reality is typically not so simple, and the results are often inaccurate. We will cover the fundamentals of switching loss, the detailed switching and conduction loss mechanisms specific to newer wide-bandgap devices, how the manufacturers measure loss and what is included on datasheets, what loss mechanisms are included in various device models, how they are accounted for, and finally how well do modeled losses compare to real-world circuit measurements. We will conclude with a summary and recommendations on best-practices for getting the most useful results.