Modeling and transmission efficiency analysis of three coil system for wireless power transmissio

Based on the theory of magnetic resonance coupling, a model of three coil system for wireless power transmission was established, and the transmission efficiency formula was derived by applying equivalent circuit theory and two port network theory. Cross coupling coefficient between transmitting and receiving coils was analyzed theoretically by using the formula. The theoretical analysis results show that the transmission efficiency of the system should decrease if cross coupling coefficient is large enough. The simulation results verify the correctness of the theoretical analysis.