Working in tandem with PowerAmerica, a public-private partnership that joined academic institutes with the U.S. Department of Energy, Kettering University has been focused on developing the next innovation in electric vehicle chargers.
The program wrapped in June of 2017, and ended with some promising results. The primary goal of the project was to develop advanced semiconductor products that could be used commercially, specifically for the charging of electric vehicles. Over the course of two years, researchers at Kettering successfully built two prototypes for new electrical battery chargers.
“We successfully demonstrated that Silicon Carbide and Gallium Nitride devices can be used to construct a level-two electric vehicle battery charger for residential applications with reasonable size, efficiently and cost. The single phase AC battery charger was meant to be a low speed electric vehicle charger that you would plug into at home. The charger controls the AC current to have unity power factor, so we aren’t wasting energy coming in from the grid by circulating it around.
While the batteries were made from different materials, they had a few distinct similarities. Both relied on dual-active-bridge topology, which provides a wide range of voltage control and isolation. For both batteries, an exotic control algorithm triple-shift-phase was utilized. This allowed for improved charge using smaller devices, at a lower cost. The team used these models to prove that cost-effective charging options are not only possible, they can be commercialized with relatively few modifications.
We successfully demonstrated that Silicon Carbide and Gallium Nitride devices can be used to construct a level-two electric vehicle battery charger for residential applications with reasonable size, efficiently and cost. The single phase AC battery charger was meant to be a low speed electric vehicle charger that you would plug into at home. The charger controls the AC current to have unity power factor, so we aren’t wasting energy coming in from the grid by circulating it around.
While this is an impressive development, it is only one step towards improving the charging prowess of electrical vehicles. As they increase in power and complexity, so too must the devices used to charge them — without becoming prohibitively expensive.
