Eigenvector Lookup Position Detection Method for Wireless Power Transfer of Electric Vehicles

To ensure alignment during wireless power transfer (WPT) of electric vehicles (EVs), position detection (PD) during parking is needed. In this paper, a low frequency (LF) positioning method based on eigenvector lookup is proposed, which is suitable for complex environment and easy to implement with simple algorithm. To reduce the calibration work and data storage, this paper proposes a simple method to decoupling the position and the rotation angle of vehicles by finding an eigenvector only corresponding to the position, independent of the angle. The real-time position is determined by comparing the similarity between the target vector formed by current induced voltages on sense coils and the eigenvector. A simple method of calculating rotation angle is also proposed. The feasibility of the proposed methods has been verified by simulation and experiments. The accuracy of detected position is less than 5% and the angle deviation is less than 10 degrees.