CN-115940440-B - Design method of negative magnetic conductivity electromagnetic structure and application of negative magnetic conductivity electromagnetic structure in wireless power transmission

Abstract

The invention discloses a design method of a negative magnetic conductivity electromagnetic structure and application thereof in wireless power transmission, wherein the negative magnetic conductivity electromagnetic structure comprises a dielectric substrate, a resonant network and a resonant capacitor, the resonant network consists of a first resonant ring, a second resonant ring and a third resonant ring which are printed on one side of the dielectric substrate, and the resonant capacitor consists of a capacitor C1 welded at two ends of an opening of the first resonant ring, a capacitor C2 welded at two ends of an opening of the second resonant ring and a capacitor C3 welded at two ends of an opening of the third resonant ring, so that the magnetic coupling effect between a transmitting coil and a receiving coil is improved. The invention solves the problem of reduced transmission coupling performance of the system under the long-distance condition of wireless power, improves the transmission distance and transmission efficiency of the wireless power transmission system, has simple preparation of the electromagnetic structure with negative magnetic conductivity and low cost, and can meet the requirement of improving the efficiency of the wireless power transmission system.

Inventors

• WANG MENG
• GUO JINGJING
• SHI YANYAN
• WANG MENGMENG
• SUN YILONG

Assignees

• 河南师范大学

Dates

Publication Date

20260508

Application Date

20221127

Claims (5)

1. 1. The design method of the negative magnetic permeability electromagnetic structure is characterized in that the negative magnetic permeability electromagnetic structure comprises a medium substrate, a resonant network and a resonant capacitor, wherein the resonant network is arranged on the medium substrate and is printed on one side of the medium substrate, the resonant network is composed of a first resonant ring, a second resonant ring and a third resonant ring, the resonant network is made of metal copper, the first resonant ring is arranged on the periphery of the second resonant ring, the second resonant ring is arranged on the periphery of the third resonant ring, the copper ring of the first resonant ring is 4.8mm in width and 0.035mm in thickness, the outer radius is 44mm, the opening width is 2mm, the interval between the second resonant ring and the first resonant ring is 1.4mm, the copper ring of the second resonant ring is 4.8mm in width and 0.035mm in thickness, the opening width is 2mm, the third resonant ring is composed of a circular copper ring and a square copper sheet, the edge of the square copper sheet is 28mm, the copper sheet is 0.035mm in thickness and the interval between the copper sheet and the first resonant ring is 1.6mm, and the opening between the copper sheet and the circular copper ring is 1.6 mm; the resonance capacitor C1 is welded at two ends of the opening of the first resonance ring, the resonance capacitor C2 is welded at two ends of the opening of the second resonance ring, and the resonance capacitor C3 is welded at two ends of the opening of the third resonance ring.
2. 2. The method of claim 1, wherein the dielectric substrate is square, the dielectric substrate is made of FR4, the dielectric constant ε r =4.4, the thickness h=1.6 mm, and the side length is 90mm.
3. 3. The method for designing the negative permeability electromagnetic structure according to claim 1, wherein the resonant network is specifically designed by setting a plane in which the dielectric substrate is located to be perpendicular to a horizontal plane, defining an x-axis on the dielectric substrate to be parallel to the horizontal plane and a y-axis on the dielectric substrate to be perpendicular to the horizontal plane by taking a geometric center point of the dielectric substrate as an origin, and establishing a rectangular coordinate system; the right direction of the center point of the medium substrate is set as the positive direction of the x axis, the upward direction of the center point of the medium substrate is set as the positive direction of the y axis, and the unit length of the rectangular coordinate system is set as 1mm; the center point and the origin of the first resonant ring coincide, the opening of the first resonant ring is arranged in the negative direction of the y axis and symmetrical to the y axis, specifically, a rectangular opening with the length of 2mm and the width of the copper ring being equal to the width of the copper ring is arranged along the x axis by taking a point O 1 (0, -41.6) as the center point, the center point and the origin of the second resonant ring coincide, the opening of the second resonant ring is arranged in the positive direction of the y axis and symmetrical to the y axis, specifically, a rectangular opening with the length of 2mm and the width of the copper ring being equal to the width of the copper ring is arranged along the x axis by taking a point O 2 (0,35.4) as the center point, the center point of the circular copper ring of the third resonant ring, the center point of the square copper sheet and the origin of the copper sheet coincide, the opening of the circular copper ring of the third resonant ring is arranged in the fourth quadrant of a rectangular coordinate system, the rectangular opening with the length of 2.4mm and the width of the copper ring being equal to the width of the copper ring is arranged along the y axis by taking a point O 3 (28.6, -3.6), and the right side of the copper sheet opening passes through a connecting line A (14, 4.8 mm).
4. 4. The method of claim 1, wherein the resonant capacitor C1, the resonant capacitor C2 and the resonant capacitor C3 are high-frequency patch capacitors, and the capacitance values are 497pF.
5. 5. The method for wireless power transmission by using the negative permeability electromagnetic structure according to any one of claims 1 to 4, wherein the negative permeability electromagnetic structure is used for assembling a wireless power transmission system, and comprises the steps of sequentially arranging two negative permeability electromagnetic structures with identical structures between a transmitting coil and a receiving coil which are arranged in parallel and opposite to each other, namely a negative permeability electromagnetic structure I and a negative permeability electromagnetic structure II, wherein the negative permeability electromagnetic structure I and the negative permeability electromagnetic structure II are arranged in parallel and opposite to each other in a coaxial manner, and the positions of the two negative permeability electromagnetic structures are determined by setting the transmission distance d between the transmitting coil and the receiving coil to be d, The distance between the negative magnetic conductivity electromagnetic structure I near the transmitting coil and the transmitting coil is d t , the distance between the negative magnetic conductivity electromagnetic structure II close to the receiving coil and the receiving coil is D r , the transmitting coil and the receiving coil are planar circular spiral coils with identical structures, the maximum radius of the coils is r, the value range of D is defined as [1.5r,4.5r ], and the value ranges of D t and D r are all [0, D/2]; gradually increasing D from 1.5r to 4.5r according to a step length of 3r/100 in a value range of [1.5r,4.5r ], calculating an S parameter value of the wireless power transmission system when two negative permeability electromagnetic structures are respectively placed at D r =d/3 and D t =d/3 positions of the wireless power transmission system, calculating the transmission efficiency of the whole wireless power transmission system by using the S parameter value as a 1 st column calculation result, then gradually increasing D from 1.5r to 4.5r according to a step length of 3r/100, calculating the transmission efficiency of the wireless power transmission system under different transmission distances as a 2 nd column calculation result when the negative permeability electromagnetic structure is not added, obtaining 100 groups of data according to a principle that the transmission distances of the two columns are the same, wherein each group of data comprises the transmission efficiency of the wireless power transmission system when the negative permeability electromagnetic structure is added under the same transmission distance and the transmission efficiency of the wireless power transmission system when the negative permeability electromagnetic structure is not added, comparing each group of data, obtaining a corresponding data of D of maximum transmission efficiency after the negative permeability electromagnetic structure is added, gradually increasing D from 200 to a value of 2D at a step length of 4980 when D is not added, gradually increasing D from a value of 200/4980 to a value of D, and gradually increasing D to a value of 2 when D is calculated according to a value of 200, when the transmission distance is D, when D t is a certain value in the value range, D r is gradually increased from 0 to D/2 in the value range of [0, D/2], S parameter values of the whole wireless power transmission system are calculated when D r takes different values, the transmission efficiency of the wireless power transmission system is calculated by using the S parameter values, D r and D t which correspond to the maximum transmission efficiency of the wireless power transmission system are respectively recorded as D ri and D ti , 100 groups of data are finally obtained according to the calculation, namely D ri and D ti , i=1, 2,3.

Description

Design method of negative magnetic conductivity electromagnetic structure and application of negative magnetic conductivity electromagnetic structure in wireless power transmission Technical Field The invention belongs to the technical field of wireless power transmission, and particularly relates to a design method of a negative magnetic conductivity electromagnetic structure and application of the negative magnetic conductivity electromagnetic structure in wireless power transmission. Background Along with the evolution of the electric energy transmission mode from a tangible medium to an intangible medium, the wireless electric energy transmission technology is deeper and deeper in the production and life of human beings, and compared with the traditional wire power supply, the wireless electric energy transmission technology is safer and more reliable. The resonant coupling type wireless power transmission technology is widely applied due to the characteristics of high transmission power, small influence on electromagnetic environment, long transmission distance and the like, but because the technology has a critical coupling state, when the transmission distance exceeds the critical coupling distance, the coupling coefficient of a wireless power transmission system is gradually weakened, so that the transmission efficiency is rapidly reduced, the transmission performance is deteriorated, and the application of the wireless power transmission technology is hindered. Aiming at the problem, the negative magnetic permeability electromagnetic structure provides a method for improving the transmission distance and the transmission efficiency of the wireless electric energy transmission system, has the characteristics of amplifying evanescent waves and improving the coupling characteristic of the resonance coil, can enable more energy of the transmitting coil to be focused on the receiving coil, improves the transmission efficiency and the transmission distance of the wireless electric energy transmission, and is simple to prepare, low in cost and easy to realize industrial production. Therefore, the design of the negative permeability electromagnetic structure has far-reaching significance for wireless power transmission. Disclosure of Invention The invention aims to effectively improve the transmission efficiency and the transmission distance of a wireless electric energy transmission system, and solves the problem that the transmission efficiency of the wireless electric energy transmission system is reduced due to weakening of magnetic coupling when the wireless electric energy transmission system remotely transmits energy. The invention aims to solve the technical problems by adopting the following technical scheme, and is characterized in that the negative magnetic conductivity electromagnetic structure comprises a medium substrate, a resonant network and a resonant capacitor, wherein the resonant network and the resonant capacitor are arranged on the medium substrate, the resonant network is printed on one side of the medium substrate and consists of a first resonant ring, a second resonant ring and a third resonant ring, the material of the resonant network is metallic copper, the first resonant ring is arranged on the periphery of the second resonant ring, the second resonant ring is arranged on the periphery of the third resonant ring, the copper ring of the first resonant ring is 4.8mm in width and 0.035mm in thickness, the outer radius is 44mm, the opening width is 2mm, the interval between the second resonant ring and the first resonant ring is 1.4mm, the copper ring of the second resonant ring is 4.8mm in width, the opening width is 2mm, the third resonant ring consists of a circular copper ring and a square copper sheet, the copper sheet of the circular copper sheet is 4.8mm in thickness, the opening width is 2.4.035 mm, the copper sheet of the copper sheet is 28mm, the interval between the copper sheet of the copper sheet and the circular copper sheet and the copper sheet of the first copper sheet is 0.035mm, and the interval between the copper sheet and the copper sheet of the circular ring and the copper sheet of the first copper sheet is 0.035mm is 1 mm; the resonance capacitor C1 is welded at two ends of the opening of the first resonance ring, the resonance capacitor C2 is welded at two ends of the opening of the second resonance ring, and the resonance capacitor C3 is welded at two ends of the opening of the third resonance ring. Further defined, the dielectric substrate is square, the material of the dielectric substrate is FR4, the dielectric constant epsilon r =4.4, the thickness h=1.6 mm, and the side length is 90mm. The specific design process of the resonant network is characterized in that a plane where the dielectric substrate is located is perpendicular to a horizontal plane, a geometric center point of the dielectric substrate is taken as an origin, an x-axis on the dielectric