Delta of Fremont, California USA, a provider of power management solutions, has begun work on a DOE-sponsored 50 percent cost-share research program to develop a solid-state transformer (SST)-based extreme fast EV charger (XFC). The project intends to produce an SST-based extreme fast EV charger (XFC) with a capacity up to 400 kW to give capable EVs a 180-mile range with less than 10 minutes of charging.
Furthermore, the proposed XFC design is projected to provide grid-to-vehicle efficiency up to 96.5 percent, with one-fourth the weight and half the size of conventional DC fast EV chargers (DCFC). It also will offer a high voltage direct current (HVDC) port to utilize energy storage and renewable energy systems, thereby minimizing power grid demand.
Team from Delta Automotive Division and Power Electronics Lab to Lead the Project
This initiative will be supported and led by a program development team comprised of industry experts from Delta’s automotive division, in the greater Detroit area (Livonia, Missouri) and researchers from the Delta Power Electronics Laboratory (DPEL) in North Carolina’s Research Triangle Park. Delta’s partners for the 3-year, US$7 million project include General Motors LLC, CPES Virginia Tech, DTE Energy, NextEnergy, and the Michigan Agency for Energy’s Energy Office and the City of Detroit’s Office of Sustainability.
The unique SST power cell design directly uses medium voltage alternating current (MVAC) at 4.8-kV or 13.2-kV, thereby eliminating the need for conventional line frequency transformer (LFT) technology, which converts low voltage alternating current (AC) to a direct current (DC) to charge the high-voltage battery in an EV.
The proposed SST coupled with a new silicon carbide (SiC) MOSFET device is expected to enables a 3.5 percent improvement in grid-to-vehicle efficiency bringing it up to 96.5 percent and a 50 percent reduction in equipment footprint. Also, the 400kW XFC prototype, which is anticipated to be ready in 2020, will feature a power level enabling 3C charging speed on tomorrow’s long-range EVs.