Relay protection method based on decentralised control logic based on two side active excitation detection

Abstract

To lower the wireless charge coil losses and leakage level of magnetic field for electromobile, a relay method with decentralised control logic based on active excitation detection by secondary side is proposed. It is guaranteed to only excite the primary coil below electromobile that raises charging requirement, to realise precise localisation and local power supply. The method fully multiplexes primary/secondary power coil and needs no additional sensing unit or centralised signal line. The active excitation detection circuit is configured as series connection-series connection compensating network and utilises its characteristic of frequency splitting to enhance intensity of detecting signal and avoid the overflow of secondary side's active excitation. A reasonable relay control flow is designed to reduce the power needed for detection and avoid conflict of simultaneous excitation of primary and secondary sides. Lastly, a simulation experiment was conducted to verify the feasibility of relay method proposed.