Efficiency Analysis and Optimization for Multiple-Receiver Magnetic Coupling Resonant Wireless Power Transfer System

In order to avoid impedance mismatch caused by spatial movement of the receivers in the multiple-receiver magnetic coupling resonant wireless power transfer (MCR-WPT) system, in this paper, we propose an equivalent method to analyze the input impedance and the transmission efficiency of the system. It is proved that when the input impedance is equal to the source impedance, i.e. impedance matching, the transducer power gain reaches the maximum equaling to the power gain. In order to optimize the transducer power gain, a L-type and reverse L-type fusion impedance matching network is added between the power source and transmitter to implement impedance matching. And the reason how the receiver coupling reduces the transmission efficiency of the system is analyzed. The proposed method is validated by numerical and circuit simulation, and the result shows good agreement between numerical and circuit simulation.