Softswitching with SiC-devices for compact onboard railway power supplies

In this work SiC-devices have been compared with state-of-the-art Si-IGBTs in a series resonant converter used for a power supply in trains. It has been shown that SiC-switches in this softswitching application further reduce the switching losses. This allowed an increase of the switching frequency from 20 kHz to 100 kHz. Consequently the transformer reduced its weight by three times and its volume by four times. The maximum measured efficiency excluding control and cooling losses was 98 %. In further work the system was operated at switching frequencies up to 220 kHz. At this frequency the maximum efficiency was almost 99 %.