Detection of EVs on IPT Highways

Electric vehicles (EVs) are quickly gaining widespread interest as attractive alternatives to conventional petrol driven vehicles. If EVs derive some or all of their power from renewable sources, then they can help reduce global dependence on fossil fuels for transportation. Inductive power transfer (IPT) is a method that can transfer power to EVs over an air gap without physical contact. If IPT systems are incorporated into highways, then EVs can be charged dynamically as they travel. This will dramatically increase the range, convenience and safety of EV charging as well as reduce range anxiety and battery bank capacities. One of the major difficulties involves detecting an EV as it travels along the highway. By detecting the approaching EV, the primary power supply can energize the primary IPT coupler buried in the roadway to enable contactless power transfer to the EV. A three coil detection system, which focuses on these sensor coils and which is independent of the specific IPT coupler used, is presented to allow the power supply to detect the approaching EV mounted secondary IPT coupler. The proposed detection method was tested on a laboratory scale prototype and can detect EVs approaching at different speeds, ground clearances, and horizontal misalignments.