Efficiency optimization method of inductive coupling wireless power transfer system with multiple transmitters and single receiver

In this paper, an analysis into the wireless power transfer system using inductive coupling with multiple transmitters and single receiver is presented. It is proved that, with certain total amount of input power from all of the transmitters, there is a maximal output power that can be delivered to the receiver. To achieve this optimal result, the electrical currents in all the transmitters shall be in-phase or 180-degree-out-of-phase. The magnitudes of the currents shall be controlled to match certain ratios. These ratios can be calculated from measurements in any known system. Experiments have been conducted to verify the theory in a wireless power transfer system with four transmitters and one receiver. The practical results match the simulated ones very well.