Impedance Identification-Based Foreign Object Detection for Wireless Power Transfer System

Metal object detection can improve the safety and reliability of wireless charging systems. A foreign object detection (FOD) method using the impedance characteristics identified on the primary side of the wireless charging system is discussed. Taking the SS compensation network as an example., metric K, is used to determine the presence of metal foreign objects and metric K2 which qualitatively reflects the impact of metal foreign objects on the wireless charging system is further designed. To convert the solution of high-order non-linear circuit equations into optimization problems., particle swarm optimization (PSO) algorithm is used to improve real-time performance and detection accuracy. In simulation., coins and metal plates are successfully detected and distinguished through proposed metrics., which verifies the feasibility of the method.