| With its unique advantages,wireless power transfer technology has made up for the shortcomings and limitations of contact power transfer technology,and has received widespread attention.Its application scenarios have gradually developed from lowpower civilian fields to high-power commercial fields.As the four basic forces,electromagnetic force widely exists in all kinds of electrical equipment,and its essence is the ponderomotive force received by the charged medium in the electromagnetic field.The long-term periodic action of electromagnetic force will cause damage and fatigue of the coupling mechanism components,and affect the safe operation of the system.In view of the basic characteristics of the structure electromagnetic force subjected to the coupling mechanism of the wireless power transfer system and the method of smoothing,the research work of this article mainly includes the following aspects:(1)Taking the structural electromagnetic force of the coupling mechanism of the wireless power transfer system in a strong electromagnetic coupling environment as the research object,the analytical expression of the electromagnetic force of the coupling mechanism is obtained based on the Maxwell stress method;the law of structure electromagnetic force for the coupling mechanism under fault conditions is analyzed,and the law of electromagnetic force of asymmetric coupling mechanism is explored at the same time,which provides theoretical support for the subsequent work of structural electromagnetic force weakening.(2)According to the difference of the force characteristics of the different components of the coupling mechanism,a method for weakening the structure electromagnetic force of the coupling mechanism based on the cancellation mechanism is proposed.Taking the sheet-shaped magnetic shielding layer as the optimization object.At the same time,the influence of the shape and structure of the magnetic shielding layer on the electrical parameters of the system is considered,and the influence of the number and width of the sheet magnetic shielding layer on the electromagnetic force of the whole structure is analyzed.(3)According to the characteristic that the structure electromagnetic force periodically acts on the different components of the coupling mechanism,a method for weakening the structure electromagnetic force of the coupling mechanism based on phase difference control is proposed.Taking the two-wire parallel transmitting coil structure as the optimization object.By adjusting the adjustable branch inductance,the phase angle of the current flowing through the adjacent turn coil is misaligned.At the same time,the influence of the adjustable branch inductance on the force of the structural components of the coupling mechanism is analyzed.(4)According to the correlation between the force of the coupling mechanism and the distribution of the magnetic field in the coupling space,a method for weakening the structure electromagnetic force of the coupling mechanism based on magnetic field optimization is proposed.Taking the variable-turn-pitch planar coil as the optimization object,the SNOPT algorithm is used to obtain the best coil arrangement,and the difference in structure electromagnetic force performance before and after the arrangement optimization is compared and analyzed.The research results of this topic on the mechanism and characteristics of the structure electromagnetic force subjected to the coupling mechanism of the wireless power transfer system show that the strength of the structure electromagnetic force is closely related to the amplitude of the current flowing through the coupling coil,the shape structure of the coupling mechanism and the material properties.Based on the basic characteristics of the structure electromagnetic force,three weakening methods are proposed,and the wireless power transfer system stress test platform is built,and the advantages and disadvantages of the three smoothing methods are horizontally compared.This subject provides theoretical guidance and reference significance for subsequent structural electromagnetic force weakening work. |
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