Engineering news
Engineers in Sweden have developed an electric vehicle charging system capable of recharging an electric vehicle’s batteries in just two hours.
Researchers at at Chalmers University of Technology developed a system which integrates the motor and battery charger and devised a power transfer method they have called the “rotating transformer”.
The researchers used the motor and inverter in the charger circuit to increase the charging power at a lower cost. The electric motor and the inverter are typically not used during a conventional battery charging cycle.
Most electric vehicles require eight hours or more of charging. Some manufacturers, such as Nissan, have recently begun offering optional fast charging systems that can halve this time.
Saeid Haghbin, lead researcher on the project at Chalmers University, said: “The question we posed was: how can we reduce the size, weight and price of the on-board 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. The battery is charged through the transformer and a split-phase electric motor that was especially designed for this purpose.”
“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, which is more expensive than the car itself.”
The research team said by integrating the components it has reduced the cost of the charging system by around $2,000 compared to today's electric vehicle chargers.
Chalmers University said that the integrated charger is still under development in the laboratory, but that the technology had been patented. The University is already working with Volvo and is looking for other industrial partners to further develop the concept.
“If we manage to solve the main problems with the battery and the battery chargers, I think the electric vehicles will succeed. And in general, I think electric transportation will become more common in the future, for example trains, trams and plug-in hybrids,” added Haghbin.