Efficiency Optimization of Wireless Power Transfer Systems having Multiple Receivers with Cross-Coupling by Resonant Frequency Adjustment of Receivers

This paper introduces a technique to optimize the efficiency of wireless power transfer (WPT) systems having one transmitter and two receivers having cross-coupling (crosstalk) among the receivers. It is shown that the presence of crosstalk may or may not be beneficial to system efficiency. The emphasis is on the improvement of efficiency in the presence of crosstalk rather than its elimination, which has not been done in previous works. To enable that, a switched capacitor circuit (SCC) is proposed that varies the resonant frequency of the receivers (by varying the net receiver capacitance) in the presence of crosstalk. This improves the total system efficiency in the presence of variable coupling and load conditions, using a perturb-and-observe algorithm.