Wireless Power Transfer System for Electric Vehicle Charging with Frequency Hopping – A Concept and Circuit Design

With the apparent reliability of wireless power transfer technology, Original Equipment Manufacturers are gradually migrating electric vehicle production charging modes from conductive to wireless. The increased users of electric vehicle wireless power transfer will introduce additional electromagnetic signals in the low frequency bandwidth which could cause interferences to various wireless operating systems. It is worth noting, vice versa, that the operation of the wireless power transfer can also be affected by near field propagated electromagnetic signals. This study shows a simplistic method to secure the electric vehicle's wireless power transfer operation from interference by providing simple resonant frequency hopping. A wireless power transfer system with a consolidated 85kHz, recommended by the Society of Automotive Engineers and non-standardized operating frequency of 250kHz was designed to this effect. The selection of 250kHz was based on a separate study detailed in this report.