800 V electric vehicles use SiC power electronics

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29 March 2023 News

The demand for EV power electronics will increase dramatically in the next ten years, primarily driven by rapid growth in the BEV car market. IDTechEx predicts a 15% CAGR globally over the next decade. Currently, the weighted-average battery capacity of BEV cars is increasing in all regions, piling pressure on battery supply chains, and creating uncertainty. The result is that drive cycle efficiency must come to the forefront of powertrain design, meaning the time has come for high-voltage wide bandgap (WBG) power electronics.

While Silicon IGBTs have dominated the medium-to-high power device range for 20 years, including in EV power electronics, they are now giving way to a new generation of WBG materials: SiC and GaN. This will fundamentally impact the design of new power devices, including the package materials, as high voltage and high power-density modules operating at higher temperatures becomes the trend.

The two drivers often cited to move from 350 ~ 400 V to 800 V and beyond are higher power levels of DC fast charging (DCFC), for example, 350 kW, and drive cycle efficiency gains. DCFC compatibility today is a relatively weak driver due to low availability versus AC chargers and the high costs associated with 800 V infrastructure. In addition, higher levels of DCFC does not necessarily drive a transition to 800 V, although it is more optimal. Tesla is a good example, having deployed 250 kW superchargers without moving beyond its 350 V platform.

The efficiency argument for 800 V is the stronger one. This allows joule losses to be reduced and high-voltage cabling to be downsized. Combined with SiC MOSFETs, it typically leads to 5-10% efficiency gains, which can potentially downsize the expensive battery, save costs, or improve the vehicle’s range, creating a competitive advantage.

Hyundai is currently demonstrating the success of 800 V platforms. Sales of the company’s models using the 800 V E-GMP platform more than doubled in South Korea to around 70 000 units/year, driven by the popularity of the IONIQ 5 and Kia EV6. This takes the 800 V car market out of the luxury segment and predominantly into mainstream car segments for the first time. To support the rapid growth, Hyundai diversified its SiC supply partnerships, and signed new deals with Onsemi and STMicroelectronics in 2022 to add to existing relationships with Infineon and Vitesco.

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800 V electric vehicles use SiC power electronics

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