Research On System Model And Controlling Of Three-Phase Magnetically Coupled Resonant Wireless Power Transfer

With the continuous development and progress of technology, the wireless power transfer(WPT)technology has attracted wide spread attention recently. Magnetically coupled resonant WPT(MCR WPT) has become a research focus because it can transmit more energy at a greater distance. In some application the relative position of the transmitter coil and the receiving coil in the MCR WPT system is not fixed, and the change of the relative position of the coils has great influence on the transmission power and transmission efficiency of the system. By increasing the transmission and receiving coils,the multi-phase MCR WPT can effectively reduce the sensitivity of the system transmission power and transmission efficiency to the coil spatial location.In this paper, a three phase MCR WPT system was proposed, and the control method was discussed. For the phase angle control was simple and easy to implement, the working principle of three-phase MCR WPT was analyzed by using the phase angle control.In order to study the influence of the coil space position change on the transmission characteristics of the system, the mathematical model was built for the three-dimensional WPT.Basing on mutual inductance model, the transmission power and transmission efficiency of the system were analyzed, and according to the Nie Neumann formula the mutual inductance calculation formula of two rectangular coils in space was derived. The variation of the mutual inductance led to the change of the system's transmission characteristics, which caused by the position change.The magnitude of the coils' mutual inductance expressed the strength of the magnetic field coupling between the coils. In order to research the magnetic field of the three-phase MCR WPT, the magnetic field distribution of the primary coil was analyzed based on Biot-Sovel law. According to the vector superposition, the expression of the magnetic induction intensity was obtained at any point in the space, Then the induction electromotive force of the receiving coil was solved. In the last the magnetic field distribution of the transmitting coil was obtained by the finite element simulation.Finally, an experimental device of three-phase MCR WPT system was designed, and the theoretical analysis was verified by experiments. Through the theoretical calculation, Through the theoretical calculation, simulation analysis and experimental verification, the transmissioncharacteristics of multi-phase MCR WPT system were analyzed in detail, which enriched and expanded the research content of multi-phase MCR WPT system, provides theoretical reference and technical reserves for the development and application of multi-phase MCR WPT system.