1. Introduction With the development of science and technology, inductive power transfer (IPT) technology has attracted more and more attention. Compared with the traditional charging method, this technology is safe, reliable, flexible and convenient, and has strong adaptability [1,2,3,4,5,6]. As a new type of power supply, it is widely used in electric vehicle charging [7], electronic products charging [8], biomedical [9] and underwater vehicle fields [10], as well as other fields.
