Method for detecting vertical offset of coupling coil using signal coil based on magnetic coupling resonance wireless power transfer system

To improve the reliability in wireless power transfer system, communication is widely used. An independent coil as the signal coil for data transfer has the advantage of decoupling power coupling mechanism and signal coil when designing the system. Besides, in some application, vertical offset of the power coil may impact the stability of the system, position detection of the receiver side power coil is needed. Method of using the signal coil for vertical offset detection is adopted in this paper, simulation result verified the feasibility. The vertical offset of the power coil can be estimated by an exponential function based on the system parameter and the current of the primary side power coil. The exponential fitting function used in the paper can be used as a reference when designing the detection.