Analysis and Comparison of Three-Level ANPC With Different Commutation Modes

Compared with the three-level neutral-point-clamped (3L-NPC) inverter, the three-level active neutral-point-clamped (3L-ANPC) inverter can overcome the drawback of unequal loss and junction temperature distribution among the semiconductor devices. On this basis, this paper analyzes the reliability of the 3L-ANPC by loss and junction temperature analysis. An electrothermal network as well as a loss prediction model of a 3L-ANPC inverter is developed for the lifetime evaluation. Moreover, this paper proposes the concept of the passive commutation mode and the active commutation mode for a 3L-ANPC inverter. Based on the developed model, the system reliability when using the two different modes is compared in terms of power losses, junction temperatures, and lifetime. Simulation results are provided to validate the effectiveness of the theoretical analysis.