Design and analysis of a wireless power transmission system with magnetic coupling resonance in the weak-coupling region

The magnetically coupled resonant wireless power transfer (MCR-WPT) system for implantable medical devices has gradually become one of the research hotspots. The transmission characteristics of the system in weak-coupling regions are of research significance. The mathematical model of the system's transmission characteristics is established by equivalent circuit theory. Several key factors that affect the transmission characteristics of the system are obtained, to include the self-inductance of the coil, the mutual inductance between the coils, and the load resistance. A magnetically coupled resonant wireless power transfer system is designed. A method of coil design is proposed. The transmission efficiency of the system in the weak-coupling region is improved by optimizing the design of the coil. Simulation and experimental results exhibited good consistency. The results show that the transmission performance of the system in the weak-coupling area is improved. This work provides guidance and practical significance for the research of the MCR-WPT system with implantable medical equipment. © The Author(s), 2019.