Parameter identification of capacitive transfer system based on Fitting Algorithm

Abstract

At present, in the wireless power transfer (WPT) of electric vehicle (EV), inductive power transfer (IPT) is still the main method. However, capacitive power transfer (CPT) has the advantages of no eddy current loss of coupling mechanism and light weight, which make it become a new research hotspot in the charging application of EV. But CPT system has high working frequency and sensitive parameters, therefore, in practical application, it is necessary to identify important parameters such as coupling capacitance and load. But at present, there are few identification methods for parameters of CPT. In this paper, a multi-parameter identification algorithm is proposed for capacitive wireless charging technology. Based on Vector Fitting algorithm and network synthesis principle, multi-parameter identification is realized. But in order to be widely used in practice, some parameters in circuit model are considered as known constraint. This can ensure that the proposed algorithm can not only realize multi-parameter identification, but also ensure the identification accuracy of system parameters in practical application.