Modulation Scheme of SiC+Si Hybrid Three-Level ANPC Inverter with Loss-Balancing Distribution

To address the problems of uneven switching loss and low efficiency existing in the three-level active neutral point clamped (3L-ANPC) inverter, a hybrid 3L-ANPC inverter composed of 4 SiC power devices and 2 Si power devices has been built, and two modulation schemes have been proposed to balance the distribution of switching loss. The proposed modulation schemes complement each other and are mixed use in a cycle. By the regulation of the proportion time in a cycle for the two modulation schemes, the balanced distribution of loss and temperature for the power devices in 3L-ANPC inverter has been realized. A 3 kW experimental platform has been constructed, the device temperature and working efficiency have been compared for 3L-ANPC inverter modulated by the proposed scheme of loss-balancing distribution and a traditional modulation scheme, the result has shown that the working efficiency has been improved by 0.5%, and the maximum device temperature difference has been reduced by 78.6%.