Analytical loss model of a three-level WBG NPC inverter comprising reverse conduction, dead time, modulation schemes and switching energy analysis

This research derives analytical switching and conduction loss expressions for three-level WBG Neutral Point Clamped (NPC) inverters that include third quadrant operation of unipolar semiconductors and dead time states for different PWM strategies. Special attention is drawn to the topological influence on the switching energies, as it leads to additional losses compared to datasheet values measured in a two-level (2L) setup. The results of the proposed equations are verified with a numerical simulation considering thermal feedback. While the state-of-the-art analytical approach leads to a deviation by a factor of up to 1.6, the proposed method offers quick and accurate inverter loss estimation.