The Optimization of Magnetic Coupling Mechanism and Circuit Parameters for Long-distance Wireless Power Transfer System

Based on the principle of magnetic field resonance coupling, the wireless power transfer over a long distance can be realized from transmitters to receivers. For the entire magnetic coupling resonant wireless power transfer system, the coupling strength between the coils restricts the transfer distance with high efficiency. The main restriction factor of the coupling coefficient is the coil parameters. However, in engineering practice, the size and weight of the magnetic coupler are limited due to environment and cost limitations. To analyze the transfer characteristics of the system, firstly, the equivalent model of the system is established by using the mutual inductance equivalent theory, and the relationship among electrical parameters is researched. Secondly, based on the finite element simulation platform, we consider the influence of the number of coil turns on the self-inductance and coupling coefficient under a certain transfer distance of 150mm and coupler size constraints. And we analyze the variation trend of the output power and transfer efficiency. Finally, by building a simulation verification platform, the transfer efficiency of the designed system is as high as 91%, which verifies the efficiency and feasibility of the designed magnetic coupling mechanism.