Automatic Active Compensation Method of Cross Coupling in Multiple receiver Resonant Inductive Coupling Wireless Power Transfer Systems
The ability to charge to multiple receivers simultaneously with a single transmitter is one of the advantages of resonant inductive coupling wireless power transfer (RIC WPT) technologies. However, in multiple receiver RIC WPT systems, each receiver often suffers from the magnetic coupling among receivers, i.e. cross coupling. The cross coupling not only complicates the control of the receivers but also significantly decreases the output power of each receiver. Hence, the purpose of this paper is to propose a compensation method of the influence due to the cross coupling. To achieve this purpose, we first analyze the requirement to compensate for the influence of the cross coupling. As a result, we reveal that it is necessary to control the phase of the current in all the receiver to be orthogonal to the phase of the transmitter current. Then, we propose the method to adjust the current phase of each receiver automatically to the desired phase by using only the phase information of the transmitter current, which results in the full compensation of the influence due to the cross coupling. Furthermore, the proposed method also compensates for the influence of a detuning of the resonant frequency of each receiver due to the natural tolerance. Experiments of a two receiver RIC WPT system successfully verify the effectiveness of the proposed method.
2019 IEEE Energy Conversion Congress and Exposition (ECCE)