The move from 400-V to 800-V battery systems in electric vehicles (EVs) brings silicon carbide (SiC) semiconductors to the fore in traction inverters, on-board chargers (OBCs), and DC/DC converters. According to market research firm IDTechEx, two drivers are critical in the move from 350-400 V to 800 V powertrains: higher power levels of DC fast charging (DCFC) like 350 kW and drive cycle efficiency gains.
However, while DCFCs aren’t widely available yet, drive cycle efficiency gains are crucial in reducing power losses and downsizing high-voltage cabling in EVs. Especially, with SiC MOSFETs, it can lead to 5-10% efficiency gains, which can downsize the expensive battery, save costs, and improve the vehicle’s range. The potential areas for drive cycle efficiency encompass battery chemistry, high-voltage cable reduction per vehicle, and improved motor design.
Figure 1 The emergence of wide bandgap (WBG) materials like SiC will transform power density, energy efficiency, and packaging in power system designs for EVs. Source: IDTechEx
Many carmakers and tier 1 suppliers are embracing 800-V drive systems to achieve much faster charging and help reduce EV weight. The 800-V drive trains—twice as much as today’s 400-V systems—can cut charging times in half. Take the Hyundai Ioniq5 and Kia EV6, which can deploy 200 kW and go from 10% to 80% charge in 18 minutes. As a result, 800-V EVs will reduce range anxiety by enabling much faster charging times.
However, the IDTechEx press release notes that the move to 800 V in EVs has been a mixed bag. Lucid Air, the first 900-V EV in production, sold around 7,000 units in 2022 after setting an initial target of 20,000 cars. Likewise, Porsche’s Taycan sales declined in 2022. In both cases, parts shortages and supply chain woes like wire harness shortages due to the Russia-Ukraine war have been widely linked to commercial pitfalls.
On the other hand, Hyundai’s 800-V vehicles—IONIQ 5 and Kia EV6—have doubled their sales in 2022, selling around 70,000 units in a year while taking EVs out of the luxury segment and into the mainstream. Here, it’s worth mentioning that Hyundai spent 2022 diversifying its SiC supply chains, bolstering its existing relationships with Infineon and Vitesco, and signing new deals with onsemi and STMicroelectronics.
Figure 2 SiC devices, which have a higher voltage rating in relation to their die size, are rapidly gaining traction in EV applications and fast-charging EV infrastructures. Source: STMicroelectronics
The success of Hyundai’s EVs, when seen in conjunction with the automaker’s efforts to bolster SiC-related supply chains, points toward this WBG technology’s crucial role in the future of 800-V cars. Especially when drive cycle efficiency comes to the fore of powertrain design centered around the power density, energy efficiency, and reliability attributes.
The move to 800-V cars is another sign that the time has come for high-voltage WBG power electronics, and here, the role of SiC semiconductors will be vital for high-voltage EV batteries and chargers.
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