Method could enable cheaper, faster EV charging
Engineers in Sweden have developed a novel integrated motor drive and battery charger for electric vehicles, which they claim could shorten charging time from eight to two hours.
"The ideal scenario would be to have a charger powerful enough to charge a car in five to ten minutes, but this would cost over $100,000," said principal researcher Saeid Haghbin. "The question we posed was: how can we reduce the size, weight and price of the on-board charger."
Since the electric motor and the inverter are not used during battery charging, the Chalmers University team looked into the possibility of using them in the charger circuit and building an integrated motor and battery charger.
"Instead of having a separate isolated battery charger, we introduced a new concept for the power transfer, the rotating transformer, which was developed to transfer electric power while rotating," explained Haghbin. "The battery is charged through the transformer and a split-phase electric motor that was especially designed for this purpose."
The researchers estimate that the technology could cut the cost of charging by around $2,000 compared to today's systems. Further testing is now under way.
