Flexible Power Control for Wireless Power Transmission System with Unfixed Receiver Position

Abstract

To improve the stability of receiving power in the wireless power transmission system with unfixed receiving position, a flexible power control strategy without the measurement in secondary side and the wireless communication between primary and secondary sides is proposed. The circuit model of a multiphase resonant inverter (MPRI) with cascaded intercell transformers (ICTs) is developed. The output voltage control strategy of the MPRI is introduced based on the iterative summation method for trigonometric functions. The circuit model of the system is derived to deduce the expressions for the key parameters. Considering the cascaded ICTs and the inductor-capacitor-capacitor (LCC) compensation circuit in the primary side, the design method of the compensation parameters is proposed based on the circuit model of the MPRI. After synthesizing the online monitoring, parameter pre-calculation, prediction of several conditions, and online learning, the flexible power control strategy is put forward for the wireless power transmission system with unfixed receiver position. Without the auxiliary positioning methods, the measurement in the secondary side, or the wireless communication between primary and secondary sides, the recognition of the load access and exit, as well as the power stabilization control after access, are realized. Finally, the theoretical analyses and the control strategy are validated by experiments.