Design and Optimization of Magnetic Coupled Resonant Wireless Power Transfer System at Weak - coupling Region

Abstract

Frequency splitting is one of the hot topics in the research of magnetic coupling wireless power transfer technology. Its purpose is to improve the transmission efficiency by eliminating the frequency splitting at the over-coupled region of the system. Frequency splitting does not occur at the weak coupling region. The transmission characteristics of the system in weak-coupled region are also of research significance. The mathematical model of the system’s transmission characteristic was established by equivalent circuit theory. Several key factors that affect the transmission characteristics of the system, self-inductance of the coil, mutual inductance between the coils, load resistance and so on, were obtained. A magnetically coupled resonant wireless power transfer system is designed and A method of coil design is proposed. The transmission efficiency of the system at the weak-coupling region was improved by optimized the design of the coil. Simulation and experimental results had good consistency. The results show that the transmission performance of the system at the weak-coupling area was improved.