As the transmission power and distance of electric-field coupled power transfer(ECPT)systems increase

the plate voltage of the coupler will also increase

which brings the radiation of fringing electric field in the surrounding environment. This paper proposes a novel four-plate coupler to suppress the fringing electric field. Based on the modelling and analysis of the novel four-plate coupler

formulas of the voltage on four plates are derived by taking a double-sided LC-compensated ECPT system as an example. Moreover

the main affecting factors of the voltage on outer plates are analyzed

and a system parameter design method considering the transmission performances of the system is provided to suppress the fringing electric field. The validity of the proposed coupler and the design method has been confirmed by the simulation results.