The demands on EV (electric vehicle) passenger car power electronics will increase dramatically in the next ten years, primarily driven by rapid growth in the BEV (battery electric vehicle) car market, where 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, according to Luke Gear, Principal Technology Analyst at IDTechEx. His new IDTechEx report provides a deep dive into what’s in store for EV power electronics.
While Si (silicon) IGBTs (insulated-gate bipolar transistors) have dominated the medium- to high-power device range for 20 years, including in EV power electronics, they are giving way to a new generation of WBG materials—SiC (silicon carbide) and GaN (gallium nitride). 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 become 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 and drive cycle efficiency gains.
However, DCFC compatibility—at 350 kW, for example—is a relatively weak driver due to its low availability versus AC chargers and the high costs associated with putting in 800-V infrastructure. Another IDTechEx report estimates that 2022 installations were around 3 million AC charging and about 50,000 DCFCs over 100 kW. Higher levels of DCFC are not necessarily driving 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 vehicle 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 (metal-oxide-semiconductor field-effect transistors), it typically leads to 5-10% efficiency gains, which can potentially enable downsizing of the expensive battery, saving costs, or improving the vehicle’s range—creating a competitive advantage.
Yet, it is a challenging time for the automotive industry, and the luxury models with 800-V systems experiencing less-than-expected success in 2022, according to Gear. The Lucid Air, the first 900-V production car, sold around 7000 units, down from an initial goal of 20,000. The Taycan was also one of Porsche‘s best-selling models in Europe between 2020 and 2021, but sales declined in 2022. (The Audi E-Tron GT shares its 800-V platform with the Taycan.) Both are the results of continued parts shortages and supply chain challenges from, for example, wire-harness shortages caused by Russia’s war in Ukraine.
Hyundai Motor Group is demonstrating relatively greater volumes with its 800-V offerings. Sales of the company’s models using the E-GMP platform more than doubled in South Korea to around 70,000 units/year, driven by the popularity of the Hyundai Ioniq 5 and Kia EV6. (The Genesis GV60 is also on that HMG platform.) These applications take the group’s pioneering 800-V technology into more mainstream car segments for the first time. To support the rapid growth, the Hyundai group is diversifying its SiC supply partnerships, signing new deals with Onsemi and STMicroelectronics in 2022, and adding to existing relationships with Infineon and Vitesco Technologies.
The Chinese OEMs are also signaling a transition to 800-V vehicles, with development plans from major brands in 2022 including BYD, XPeng, Great Wall Motors, and GAC. These vehicles will most likely use SiC MOSFETs, allowing the SiC industry to tap into the world’s largest EV market; China sold over 6.5 million EVs in 2022.
While the 1200-V SiC MOSFET, adopted in 800-V vehicle platforms, will play a key role in optimizing drive-cycle efficiency, it is still only one piece of the puzzle. Drive-cycle efficiency can be improved in many areas, from improved battery chemistry to solar bodywork, high voltage cable reduction per vehicle, other 600-V SiCs, and improved motor design. The task for automakers is to work toward constantly improving the overall drive-cycle efficiency to balance against battery-supply constraints.
“800 V will eventually be the automotive standard, but the transition will be gradual,” concluded Gear, on LinkedIn. “It will be the standard because it’s better—greater efficiency, less battery capacity (less use of critical raw materials, lower cost, etc.), more range, and faster charging. It will be gradual because it requires deep system design changes and charging infrastructure upgrades to get the true benefits, which will take time due to legacy designs. Hyundai is a great example of what can be achieved when moving to 800 V starting from a fresh platform.”
“800 V is the starting point for the heavy-duty sectors due to greater power requirements and larger batteries looking to charge at 2-4 C,” Gear added. “For trucks, 800 V is typical, while boats and ships start at 1000 V.”
To find out more about the IDTechEx power electronics report, including downloadable sample pages, visit www.idtechex.com/powerelec. The report covers technology insights into the evolving semiconductor and package materials such as Si, SiC, and GaN semiconductors; die-attach materials; wire bonding; and thermal management. It presents granular forecasts detailing unit sales and demand for inverters, onboard chargers, and DC-DC converters segmented by voltage and semiconductor type.
On March 30th, report author Gear will also be presenting a webinar called Wide Bandgap Power Electronics: The New EV Battery. The event will cover market demand, future developments, and benchmarking of SiC versus GaN; the materials evolution for power packages and industry pain points; and a market outlook for EV power electronics broken down by voltage.