What you'll learn:
- Why was the CoolSiC MOSFET cell design implemented into the HybridPACK Drive?
- How traction inverters based on CoolSiC power modules impacted Hyundai's E-GMP platform.
At this year’s virtual PCIM trade show, Infineon Technologies introduced a new automotive power module that leverages its CoolSiC MOSFET technology. The HybridPACK Drive is a full-bridge module with 1200-V blocking voltage optimized for traction inverters in electric vehicles (EVs). It’s said to offer higher efficiency in inverters with longer ranges and lower battery costs, particularly for vehicles with 800-V battery systems and larger battery capacity.
Silicon-carbide (SiC) devices operate at much higher drain-induced electric fields in the blocking mode compared to their silicon counterparts. One of the most important acceptance criteria is the reliability of the device under the operating conditions of its target applications, which requires maintaining the reliability of the oxide in the blocking stage. Infineon’s overall goal here is to combine the low on-resistance (RDS(on)) offered by SiC with a working mode in which the part operates in the well-known, safe oxide field-strength conditions.
Consequently, the company decided to focus on trench-based devices, moving away from a planar surface with high-defect density toward more favorable surface orientations.
The CoolSiC MOSFET cell design was developed to limit the gate oxide’s electric field in the on-state as well as in the off-state to maintain reliability. Furthermore, the 1200-V variant has a low RDS(on), said to be stable and reproducible even in mass production.
Generally, dc electric-vehicle chargers are an attractive choice because they allow for much faster charging: a 150-kW charger can put a range of 200 km on an EV in around 15 minutes.
Hyundai E-GMP
By using traction inverters based on Infineon’s CoolSiC power module in its 800-V Electric Global Modular Platform (E-GMP), Hyundai was “able to increase the range of the vehicle by more than 5% because of efficiency gains resulting from the lower losses of this SiC solution compared to Si-based solutions,” said Dr. Jin-Hwan Jung, Head of the Electrification Development Team at Hyundai Motor Group
Hyundai’s E-GMP comprises the chassis of the vehicle, including the battery, motor, and power electric system. The platform’s scalable wheelbase allows it to form the backbone of many different types of vehicles. With the rapid charging of the E-GMP, the system is fully charged in just 18 minutes, and offers 500 km of driving range. In just five minutes, the battery can charge enough for a range of 100 km. And since drivers can charge with either a 400- or 800-V charger without having to adjust anything manually, they can visit any nearby charging station.
HybridPACK Drive Details
The HybridPACK Drive was first introduced in 2017, using Infineon’s silicon EDT2 technology. It offers a scalable power range of 100 to 180 kW within the 750- and 1200-V class. This product is the company’s leading power module with a track record of more than one million pieces shipped for more than 20 EV platforms.
The new CoolSiC version is based on Infineon’s SiC trench MOSFET structure. Compared to planar structures, the trench structure enables a higher cell density and can be operated at lower gate-oxide field strength for increased reliability.
The power module offers an upscale path from silicon to silicon carbide with the same footprint. Thus, the inverter design can achieve higher power of up to 250 kW in the 1200-V class, greater driving range, and smaller battery size. To offer an optimal cost-performance ratio for different power levels, the platform comes in two versions with different chip counts, resulting in either a 400- or 200-A dc rating version in the 1200-V class.
Amid the growing demand for SiC-based devices, Infineon Technologies has strengthened its supply chain for an extensive range of SiC-based material, including epitaxy through a supply contract with Japanese wafer manufacturer Showa Denko K.K.
“The expansion of our supplier base with Showa Denko for wafers in this growth market marks an important step in our multisourcing strategy,” said Peter Wawer, President of the Industrial Power Control Division at Infineon. “It will support us to reliably meet the growing demand mid to long term. Furthermore, we plan to collaborate with Showa Denko on the strategic development of the material to improve the quality while cutting costs at the same time.”
The new HybridPACK-Drive CoolSiC is in production now and will be available starting June 2021.