The fundamental harmonic approximation method is the main research method of wireless power transfer (WPT) technology. This method equates the rectifier load fundamental impedance to a pure resistance, which provides a basis for modeling and analysis of the WPT system. However, this method ignores the effect of rectifier load harmonic impedance, which leads to a large error between the actual response and the theoretical analysis, affects the model accuracy of the system and limits the further optimization design of WPT system. In this paper, the WPT system based on parallel-series/series (PS/S) compensation network is taken as the research object, the reason for the error generated by the fundamental harmonic approximation method is analyzed and an accurate calculation method based on the iterative method for the rectifier load equivalent impedance is proposed. On this basis, an accurate circuit response model of the WPT system is established. Finally, the correctness of the system response model is verified through simulation.

wireless power transfer (WPT); PS/S Current-Fed compensation network; accurate calculation method of rectifier load; system response modeling