Flexible Energy-Transfer Control of Dynamic Wireless Power Transfer System Based On Estimation of Load and Mutual Inductance

Abstract

Dynamic wireless power transfer (DWPT) technology is gradually making the prospect of charging on road of EVs (electirc vehicles) possible. However, DWPT system should be optimized in many aspects before it can really be utilized on road. For example, the control of energy transfer for a DWPT system is much complicated than a static wireless power transfer (WPT) system since the coupling of transceiving coils changes with the moving of the EV. In this article, an energy transfer control method based on the estimation of the load and mutual inductance of the segmented DWPT system is proposed. The relation between the load and the reflected impedance of the primary side is studied, and the parameters of the secondary-side <i>LCC</i> network are tuned to avoid the two-solution problems in the estimation of the load. Based on the results of estimation, a two-cases controlling strategy is proposed to switch between power-<small>on</small> station and detection station of the DWPT system according the target of energy transferring. A 800-W prototype of four-transmitting-coil dynamic WPT system is built and experiments show that the proposed energy-transfer control is proved to be efficient to regulate the energy and achieve fast response characteristics. Compared with the traditional controlling methods which usually aim to achieve maximum energy transfer, the method in this article can control the transferred energy according to the target value of energy, making the control more flexible without the use of communication.