Onsemi Designs DC SiC Power Modules to Fast Track EV Charging
One critical barrier to EV adoption is their notoriously long charge times. Onsemi aims to address one piece of the puzzle with new power-integrated modules.
At CES last week, Onsemi announced nine new power-integrated modules (PIMs) for bidirectional DC-DC power transfer. As the number of electric vehicles increases, designers and consumers alike are concerned about the long charge times associated with large EV batteries. In response, Onsemi released these new PIMs to speed up charge times.
New Onsemi PIMs feature high efficiency and low on-resistance, optimizing bidirectional power transfer for advanced applications.
While EVs may be a target application for the new devices, any high-power DC-DC conversion could benefit from the new SiC PIMs, according to Onsemi. The improved efficiency and performance of SiC could prove especially useful when power must flow bidirectionally, such as in vehicle-to-grid applications.
Efficient, Two-Way Power
Designing a one-way DC-DC converter is not an easy task, especially in applications with high currents or voltages. Considering the number of architectures available for DC-DC conversion, it can be difficult to know which one to use in each situation.
This problem is only amplified for EV charging, where high voltages and currents are standard to support faster charging rates. Designers must also consider the efficiency of the system since switching losses can quickly create thermal problems and waste energy. An added layer of complexity comes with bidirectional power transfer, which supports vehicle-to-grid applications.
High-current/voltage and bidirectional power systems may require new architectures such as the dual active bridge CLLC converters.
Efficient and high-performance power electronics can minimize switching losses and aid high-level integration and qualification. The new PIMs from Onsemi may not only help improve existing performance but pave the way for new applications using EV batteries.
SiC-Enabled Performance
Inside the new Onsemi EliteSiC PIMs are several Gen3 SiC MOSFETs reported to have the “lowest switching losses and highest efficiency in the industry.” These performance gains are likely due to SiC’s intrinsically better high-power switching performance compared to silicon. The PIMs (datasheet linked) support many architectures, such as half-bridge, full-bridge, and T-type, and have an on-resistance as low as 3 mΩ.
Each PIM supports a maximum breakdown voltage of 1,200 V with 350 A continuous current (700 A pulsed), allowing designers to increase the power handling capability of their on-board and off-board charging solutions. The devices, which come in F1 and F2 packages, support up to 100 kW of output power. The PIMs can also be used for bidirectional charger controller development.
Switching energies (Eon, left. Eoff, right.) show the improved performance of the SiC FETs, reducing wasted energy and increasing the efficiency of DC-DC converters.
In an example application, Onsemi reported that the size and weight of chargers can be reduced by 40% and 52%, respectively. A resulting DC fast charger could theoretically charge EV batteries to 80% in 15 minutes. Onsemi offers additional design support for the PIM models, including its PLECS model generator and Elite Power Simulator.
Continuing EV Momentum
While traditional ICE-powered vehicles likely won’t be completely phased out for quite some time, devices like these new PIMS move the needle on EV performance and accessibility. As more R&D effort is placed toward developing faster charging stations and improved bidirectional power transfer, EVs could play a critical role in supporting future grid operations. As the electrification of our world continues, the improved efficiency of the newest Onsemi PIMs could be the first step toward changing how power is delivered and managed.
All images used courtesy of Onsemi.
