Which voltage class is commonly used for the power devices in the traction inverter of an electric vehicle with an 800 V battery?

Answer: C. 1200 V class

Power devices see not only the supply voltage itself but also voltage variations with state of charge and surge voltages during switching, so a breakdown voltage with margin is required. Devices in the 650–750 V class are commonly used for 400 V systems and the 1200 V class for 800 V systems, and SiC MOSFETs, which have low losses even at high breakdown voltages, are increasingly adopted. Moving to 800 V halves the current for the same power compared with 400 V, making it easier to raise fast-charging power and allowing thinner cables. The 650 V class is the guideline for 400 V systems.