2023 Volume 31 Issue 2 Pages 90-95
Wireless power transfer via magnetic resonant coupling can be used to supply power to a mobile robot within a few meters of a transmitter coil. However, when the robot moves or its power consumption fluctuates, its input impedance varies greatly and power reflection occurs in case of impedance mismatch. Therefore, we propose the use of multiple identical driver coils on the transmitter side in order to match the input impedance. The input impedance is matched and power reflection is eliminated by switching driver coils, i.e., regulating the coupling coefficient between the driver and the transmitter. In addition, the winding number of the receiver coil can be switched to relax the design condition of the drive coil. The experimental results showed the input impedance was well-matched automatically under the varying distance and load resistance. Therefore, the proposed system was expected to solve the power reflection issues in practice.
