A micronavigation solution in the form of magnetic positioning is designed to ensure the vehicle is in exactly the right spot for charging. Magnetic field sensors in the charging pad send the measurement results back to the electric vehicle (EV) via WLAN. The positioning system works in the long wave range (LW) and is expected to be able to locate the charging pad to within centimetres even through snow or leaves.
The electric vehicle recharges automatically at a rate of 11 kilowatts while being permanently monitored for safety reasons. Looking ahead, the global standards currently under development would even make it possible to recharge a succession of autonomous EVs efficiently, with each vehicle ‘re-parking’ to release the charging pad for the next.
Continental’s AllCharge simplifies cable-based charging
Continental aims to establish the AllCharge system as a sort of ‘universal key’. To achieve this, the engineers have turned the electric drive into a charging system by developing an upgrade for the electric motor and inverter (converter between direct current (DC) and alternating current (AC)) that adds a recharging capability. A DC-DC converter always supplies the optimum voltage to the battery. When charging, alternating current flows from the charging station through the electric motor to the inverter and from there as direct current to the battery. Conversely, the direct current from a charging station directly charges the battery via the DC-DC converter.
Continental’s system will avoid the need for ever larger and costlier on-board chargers since wired charging always requires alternating current from the grid, which then has to be converted to direct current. AC charging with the AllCharge system does not require an on-board charger, so the battery can charge at a rate of up to 43 kilowatts with the appropriate AC infrastructure.
This means that charging for a period of ten minutes increases the range by up to 50 kilometres. The new system also allows the use of 400-volt DC fast-charging stations, which can increase the range by up to 150 kilometres in ten minutes. At 800-volt DC stations, vehicles with very large batteries can increase their range by up to 300 kilometres in ten minutes. The AllCharge system can also be used bidirectionally and supply alternating current without limiting power, making electric cars usable as mobile energy storage devices. Production for the new charging systems is slated for 2022.