Decrease of SiC-BJT driver losses by one-step commutation

The silicon carbide bipolar junction transistor (SiC-BJT) is a promising power semiconductor device for high efficient motor drive inverters. Especially with the very low on-state voltage drop and high switching speed it challenges the state of the art device - the silicon IGBT. The main disadvantage is the high driver loss in on-state compared to its voltage driven competitors, though. With the one-step commutation in voltage source inverters (VSI) a new approach on decreasing on-state losses is presented. An “all-SiC” inverter with DC-link consisting of SiC-BJTs and SiC-diodes has been designed and build-up. First measurements indicate that by using one-step commutation instead of the conventional one driver losses can be cut in half. This leads to an increase of efficiency of SiC-BJT voltage source inverters.