Continental presents automated wireless charging for EVs
At next month’s Continental Tech Show, Continental will preview inductive charging technology, installed in an electric vehicle, ahead of the IAA Frankfurt Motor Show in September.
The charging power is transferred wirelessly from a ground-based charging pad to a receiver pad on the underside of the vehicle. All the driver has to do is to park over the charging pad, assisted by Continental micro-navigation. As soon as the vehicle approaches a parking bay equipped with inductive charging, an authentication dialogue with the charging station is executed automatically. A human machine interface (HMI) shows the driver when the vehicle has reached the correct parking position and confirms that charging has started.
Thomas Röhrl, Contintental expert for the inductive charging system, explains: “At present, there can be any of a number of reasons why EV drivers are reluctant to use every available opportunity to recharge their vehicle. If it’s cold outside or wet they may not feel like getting out and grappling with the charging cable.” Particularly when drivers only intend to make a short stop, this may all seem like too much trouble and they will prefer to let the opportunity pass by.” The charging solution can also be used for e-bikes.
Röhrl continues: “Taken together, a large number of short charging sessions provide just as much energy as one long session.” Additional, says Continental, inductive charging involves virtually no effort on the part of EV drivers, and it expects an improvement in overall energy balance, and therefore an increase in the vehicle’s available range at any given time.
“We have to make recharging more practical and user-friendly,” says Röhrl. “Inductive charging technology will be a big step towards achieving this.” Continental has developed a comprehensive inductive charging solution capable of recharging the EV at a rate of up to 11kW. This system charges the vehicle automatically and safely as soon as the vehicle is parked in the correct position over the system’s ground pad. The vehicle-mounted inductive charging components comprise a receiver pad, power electronics, controllers and a human-machine interface to assist with precise parking. The positioning system was developed by Continental. The positioning tolerance of better than 100mm ensures the best possible power transfer from the ground pad to the vehicle, says Continental.
As soon as the wireless authentication process has been successfully completed and the vehicle is correctly parked, the charging pad starts transmitting power. The stepped ramp-up to full output power is completed in just seconds. If the integrated gap-monitoring function detects the intrusion of a foreign object under the vehicle, between the ground pad and the vehicle pad, power transmission is immediately interrupted. Inductive charging technology takes up relatively little space in a garage or parking lot compared with cable-based technology. The ground pad, which is capable of withstanding a load of up to 500 kg, is either located on or recessed into the ground, making the system easier to integrate in confined parking bays than a wall box. In public parking bays (in parking garages or at shopping malls), a further advantage of inductive charging technology is the greatly reduced risk of vandalism.
At a charging rate of 11kW, every minute of charging time provides approximately 1km of driving range, so in the space of a 20minute charge, (the time it takes to visit the shops), the available driving range can be increased by up to 20km.
Continental is also playing an active role in standardisation efforts. As a member of the public-funded German ‘StiLLe’ project, Continental is involved in drafting technical recommendations for the standardisation of inductive charging systems.