Abstract: In high-power traction converter，SiC devices with many advantages such as fast switching speed，

high temperature resistance and low switching loss are used to replace Si devices. The three-level active neutral-pointclamped（3L-ANPC）converter based on SiC devices can reduce the burden of heat dissipation systemof the converter，realize the lightweight of the traction system，and improve the power density and overall efficiency of the converter.Four three-level ANPC converter topologies，including two SiC+Si hybrid 3L-ANPC topologies，all SiC 3L-ANPC topologies，all Si 3L-ANPC topologies and modulation strategies applicable to different topologies，were analyzed in detail. Combining the commutation process of the four topologies working under their respective optimal modulation strategies，the power loss and thermal balance characteristics of the different topologies were quantitatively analyzed and compared by simulation. The results show that the full SiC 3L-ANPC topology has the most balanced loss distribution and the highest working efficiency，and the 2-SiC hybrid 3L-ANPC topology has lower cost on the basis of ensuring performance，so it is a cost-effective choice for traction converters using SiC devices.

      Key words: three-level active neutral-point-clamped（3L-ANPC）converter；loss analysis；pulse-widthmodulation （PWM）；SiC