What does it mean that all models feature a full-domain SiC (Silicon Carbide) high-voltage platform, and what are its advantages?
When we commonly refer to IGBT/SiC, we are talking about the power modules in the electric drive controller. These are switching devices composed of one or more parallel-connected power chips. There are IGBT type chips made of Silicon (Si), and MOSFET type chips made of Silicon Carbide (SiC) (yes, IGBT is a semiconductor type, while SiC refers to the chip material). Power modules are responsible for converting DC to AC during motor driving and AC to DC during energy recovery, so their efficiency is crucial for electric vehicles. SiC MOSFETs have lower switching losses and higher efficiency compared to Si IGBTs. Because the manufacturing process for SiC is difficult, has a long production cycle, and results in low yield and good product rates, the price of SiC is 2 to 5 times that of Si.
A full-domain SiC high-voltage platform means that not only do the high and low trim versions of the Xiaomi SU7 use SiC silicon carbide power modules for their drive motors, but two other key components with high energy efficiency requirements—the On-Board Charger (OBC) and the air conditioning compressor of the thermal management system—also contain silicon carbide materials to achieve better energy efficiency performance. Full-domain silicon carbide is one of the technical means used by the Xiaomi SU7 to achieve extreme overall vehicle low energy consumption.