The In-phase Eigenstate Working Mechanism Of Multi-base Station Local Area Wireless Power Transfer Grid

As a new practical power supply technology,Magnetic Coupling Wireless Power Transfer(MC-WPT)technology has the advantages of portability,safety and reliability that wired charging does not have.It has a wide range of application prospects in the field of portable electronic products,medical equipment,transportation and aerospace,and intelligent living furniture,and has become a research hotspot in the field of electrical engineering.At present,the application mode of MC-WPT system is mainly to supply power to terminals within a specific limited range.With the expansion of the application field,the demand for multi-degree-of-freedom real-time wireless power supply within the local space like Wi Fi is becoming more and more strong,and so that building a Wireless Power Transfer Grid(WPTG)is an important development direction.At present,WPTG is still in the initial stage of basic theoretical research,and the underlying physical properties and working mechanism need to be further studied.In this thesis,taking the multi-base station WPTG as the object,combined with circuit theory and eigenstate theory,the general mathematical model of multi-base station local area WPTG is established.And the energy efficiency characteristics of multi-base station local area WPTG are analyzed in depth,and a dual-parameter identification method of load and mutual inductance is proposed,and then the in-phase eigenstate working mechanism of multi-base station is constructed to ensure that the system can also take the efficiency into account under the condition of maximum power output.The main work is as follows:Taking any multi-base station local area WPTG as the object,based on the equivalent circuit analysis method,the general mathematical model is constructed,and the conclusion that the power of the receiver is the maximum when the excitation current of each base station is in the same phase.Combined with the high efficiency of MC-WPT system working in the eigenstate,the idea of multi-base station in-phase eigenstate energy supply is proposed,and the general mathematical description of the multi-base station in-phase eigenstate energy supply mechanism is established based on the eigenstate theory,which can also take the efficiency into account under the premise of ensuring the maximum power output.Aiming at the problem that multi-base station in-phase eigenstate energy supply needs to understand the load position and resistance,a dual-parameter identification method of MC-WPT system load and mutual inductance based on eigen-parameter calculation is proposed,which has the advantage that it does not need to detect secondary side parameters,nor does it need to communicate with the primary side of the secondary side,only needs to detect the output voltage of the primary side inverter and primary side current,and can quickly and accurately identify the load and mutual inductance of the system.This method is simple to operate and fast to identify,and can also ensure efficient power transfer in parameter identification mode.Based on the proposed theory,the dual-base station wireless power transfer system is designed,the parameter conditions of the dual-base station wireless power transfer system are derived,the amplitude and phase expression of the excitation voltage of each base station in the in-phase eigenstate are determined,and then the characteristics of the system in the in-phase eigenstate,including energy efficiency characteristics,excitation amplitude ratio characteristics,etc.,are analyzed in depth,and simulation is carried out.Finally,the corresponding experimental platform is built to verify the proposed dual-parameter identification method of MC-WPT system load and mutual inductance based on eigen-parameter calculation and the in-phase eigenstate energy supply mechanism of multi-base station,which confirms the accuracy of the parameter identification method proposed in this thesis and the characteristics of the in-phase eigenstate energy supply mechanism that can take the efficiency into account under the condition of ensuring maximum power transmission.71 figures,5 tables,and 101 references are included in this thesis.