Current Derating – the untold weakness of high speed IGBT drive systems

Current Derating is one of the major problems of traditional IGBT technology powering high speed e-motors. Due to the tremendously increasing switching losses when increasing the PWM switching frequency, you need to derate the current (blue curve). This ends in the absurdity that the inverter modules can only supply 50-60% of their nominal power and therefore many modules have to be connected in parallel to reach the required current.

What happens if you switch to SiC technology? The switching losses of the wide bandgap material are massively reduced. So far so good. But even here there are differences. Comparing the SiC curves in the above picture, the superior behavior of the AVL Spectra SiC drive is crystal clear. AVL invested 3 years in R&D to optimize the SiC drive commutation cell. The effort was worth it! The AVL solution impresses with superior behavior and needs no derating up to 90 kHz. Therefore it is the optimal solution for powering high speed e-motors, but also for battery emulation!