Over the last couple of years there have been a number of wireless chargers hitting the market, such as the Powermat and the WildCharge. These are designed to keep mobile devices charged and ready without dealing with the hassle of cords and connections. The technology has also been proposed as a way to recharge vehicles while they are parked without having to plug them in, while some companies are looking at charging cars while they are moving from electrical conductors embedded in the road. Now, a group of students in Germany has taken that idea and run with it by building an electric vehicle called the E-Quickie that runs on wireless power transmission.
Looking a bit like a recumbent bike with a driver’s cabin, the E-Quickie was built by students at the Karlsruhe University of Applied Sciences (HsKA) to investigate the practicality of a wirelessly powered electric vehicle. It gets its energy from electric conducting paths on the ground with receivers underneath the car taking energy from the tracks through electric induction and directing it to the car’s electrical hub drive.
One student working group took care of setting up the racing track, which was provided by the firm SEW, in Bruchsal. Two other teams were dedicated to the vehicle’s energy absorption and the safety of the entire system.
They designed the individual vehicle components, such as the steering and braking system and the chassis, using high-tech materials. Keeping the weight of the vehicle to a minimum and its aerodynamics were also important factors for designing the outer skin of the vehicle’s body, for which the students used carbon fiber. Before construction of the vehicle, all its components and finally the whole vehicle were optimized by computer in a virtual wind channel.
The end result was a three-wheeled vehicle that weighs just 60kg (132lb). However, Prof. Jürgen Walter from the faculty of Mechanical Engineering and Mechatronics and head of the project is confident this can be reduced to 40kg (88lb) through further optimization.
“With other vehicle types you have a weight ratio between driver and vehicle of 1:10/1:15. We’re aiming for a ratio of 1:2 through further development of the E-Quickie,” said Walter.
Even though the vehicle’s motor only has a horsepower of 2kW, its light weight means it is still able to reach a speed of 50km/h (31mph). Even though the vehicle draws its power from the track, it still has batteries onboard. However, these serve only as a buffer and are therefore much smaller than those found in other electric cars which draw energy from batteries exclusively.
“The aim was not only to show how quickly you can move around with the E-Quickie, but most of all how energy efficient the car is”, explains Walter. “We went to the start with half-filled batteries and returned with full ones.” For what then are batteries used for in this system of energy transfer? As soon as the car leaves the electrical conductor tracks, the power supply to the motor is interrupted. “Here the small accumulators then jump on-board the E-Quickie as an energy buffer,” explains Walter, “for example when it’s driven into the garage.”
The team has already achieved success: On May 19-20 this year, the students took part in the Karlsruhe E-Meile, completing 40 laps on the 222-meter (728-ft) conductor track. The team plans to use the test track at the HsKA campus to continue optimizing the vehicle for reduced energy consumption and weight.