A Guided Wireless Electric Vehicle Charging Strategy Based on In-Plane Magnetic Field

A guided wireless electric vehicle (EV) charging strategy was proposed to effectively mitigate the issue of misalignment, which could result in decreased charging efficiency in wireless charging systems. Typically, sensor data fusion and mapping-based techniques are employed to establish the relationship between the sensor output and coil position. However, the implementation of these techniques necessitates sensor arrays or imposes a substantial computational burden. To address these challenges, an alternative methodology arises through the estimation of coil coordinates based on magnetic field components. In this proposal, the ratio of in-plane magnetic field components (denoted as
${B}_{y}$
/
${B}_{x}\text {)}$
is employed for the determination of coil coordinates. The proposed method is operationalized with the integration of merely four dual-axis anisotropic magnetoresistive (AMR) sensors affixed at the receiver coil side as point field detectors. This streamlined configuration facilitates the derivation of a concise formula for the numerical positioning of the coil. Following the adjustment of the receiver coil contingent upon estimated coil coordinates, a wireless charging stage was triggered on the transmitter coil side. The trigger signal was generated by the relay’s action, obviating the necessity for supplementary communication devices. A laboratory-scale wireless EV charging prototype was developed and tested. The proposed method possesses the merits of being accurate, computationally efficient, and communication-free. There were 187 samples demonstrated in the testing range of
$20\times 16$
cm. The positioning errors were found to be less than 1 cm which validated the effectiveness of the proposed method.