Interference Risks from Wireless Power Transfer for Electric Vehicles

Wireless power transmission (WPT) for electrical vehicle (EV) charging is a relatively new application of wireless energy transfer and its potential electromagnetic (EM) interference impact on other systems has not been investigated in depth. The proposed frequencies for WPT-EV are also used by radiocommunication systems or services. WPT systems transfer high power and can cause out-of-band and spurious EM emissions. In the analysis, both current and proposed emission limits for WPT systems are considered.For a number of radiocommunication services, separation distances from WPT-systems to protect the radio services in the VLF to MF-bands are derived. The interference risk is analyzed for the radio services standard frequency and time signal (SFTS), non-directional beacon (NDB) and differential transmissions for global navigation satellite systems (DGNSS). The overall conclusion is that radiated emission from WPT may cause non-negligible interference impact on radio-based services at co-location distances ranging from a few tens of metres up to the order of tens of kilometres.