Frequency Stability Analysis and Charging Area Expanding Optimal Design for Matrix Coupling Mechanism in Wireless Power Transfer System

The matrix coupling mechanism brings flexibility and reliability to energy supply in the form of multiple transmitting coils and is now favored in most wireless energy transmission applications, such as wireless charging boards for mobile phones, inspection robots, and so on. However, the process of considering the layout of the matrix coupling mechanism and the output performance based on the target in space is very complex, while also taking into account the need to avoid impedance changes caused by cross-interference between each unit, which can lead to frequency inconsistency. This paper proposes a design method based on space charging area expansion for matrix coupling mechanisms, and on this basis, it focuses on analyzing the impedance mismatch phenomenon caused by cross mutual inductance and inconsistent mutual inductance between coil units, in order to obtain the optimal topology to avoid frequency drift as much as possible. Finally, the effectiveness of the method is validated through simulation and experiments.