A Quasi 2-Level Modulation Technique to Increase Efficiency and Reduce Motor Overvoltage

Inhalt:
This paper explores a method to increase the efficiency of an IGBT B6 converter by using a small additional SiC T-branch. The resulting combination of 3-Level and quasi- 2-Level modulation significantly improves the efficiency by making optimal use of the SiC MOSFETs. The topology is ideally suited for a method of reducing motor overvoltage without the use of additional filters. This is also explored in this paper by conducting measurements at a motor test setup. Switching losses are also evaluated for the small turn on time of the T-branch, than can occur during this quasi 3-Level operation.