Accurate and Efficient Loss Characterization Method of 3-Level NPC Switching Arms Based on H-bridge Testing Circuit

Three-level neutral point clamped arms (3L-NPC arms) are widely applied to power electronic converters, and their switching loss characterization is crucial for the reliability evaluation of the converters system. The widely used double-pulse testing (DPT) method is inaccurate and inefficient in extracting switching losses of 3L-NPC arms, because the parasitic parameters of DPT circuit are different from the practical 3L-NPC inverters, and only one device can be tested at a time. In this paper, a novel loss characterization method of 3L-NPC switching arms based on H-bridge testing circuit is proposed to solve the problems. The proposed testing circuit is closer to 3L-NPC inverters in practical use and can test multiple chips at one testing period. Simulation results validate the feasibility of the proposed testing method.