Active Regulation of Electromagnetic Force in Wireless Power Transfer Systems

To reduce the interference from the electromagnetic force caused by coupling coils due to distance changes in a wireless power transfer (WPT) system, this paper conducts a theoretical analysis of the factors influencing the electromagnetic force experienced by the receiving coil. Maxwell electromagnetic simulation is used for modeling and analysis, revealing the trends in the electromagnetic force exerted on the receiving coil. Based on this analysis, a method is proposed that actively adjusts the working frequency of WPT to alter the current phases of the transmitting and receiving coils, thereby regulating the magnitude of the force on the receiving coil. Finally, mechanical tests, including torque experiments, were conducted to validate the proposed method. The electromagnetic force on the coil in the microgravity isolation platform of a space station was reduced from 961 μN to 113 μN, a level which plays an important role in improving the microgravity index of the system.