Real-time coupling coefficient estimation and maximum efficiency control on dynamic wireless power transfer for electric vehicles

Maximum efficiency control using a DC/DC converter on the secondary side can improve transmitting efficiency in dynamic wireless power transfer system for electric vehicles. However, the information of coupling coefficient has to be estimated to implement the control although coupling coefficient changes dynamically. In this paper, a simple method of coupling coefficient estimation with RLS (Recursive least squares) filter is proposed. Dynamics of WPT system is analyzed with transfer functions. Moreover, the modeling and the control method of DC/DC converter are introduced. The experimental results of real-time coupling coefficient estimation and maximum efficiency control are provided and they indicate the effectiveness of the proposed control in a real dynamic wireless power transfer system for EVs.