Comprehensive evaluation method for wireless charging magnetic coupler

Abstract

The invention discloses a wireless charging magnetic coupler comprehensive evaluation method comprising the following steps: S1, obtaining a maximum mutual inductance, a maximum anti-offset distance and a mutual inductance standard deviation through a first obtaining channel, the maximum mutual inductance and the mutual inductance standard deviation having a function relationship, the performance indexes of the magnetic coupler are jointly determined by the three performance indexes of the maximum mutual inductance, the maximum anti-offset distance and the mutual inductance standard deviation; s2, correspondingly calculating weights corresponding to the maximum mutual inductance, the maximum anti-offset distance and the mutual inductance standard deviation according to the maximum value of the performance index of the magnetic coupler; and S3, obtaining the maximum mutual inductance and the maximum anti-offset distance through the second obtaining channel, and obtaining the performance index of the magnetic coupler. According to the comprehensive evaluation method for the magnetic coupler, the coupling strength, the anti-offset capability and the magnetic field uniformity are comprehensively considered, the performance of the magnetic coupler can be comprehensively evaluated, the calculation process is simple, the expression form is direct, and a scientific basis is provided for design and optimization of the magnetic coupler.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics and wireless charging, and in particular to a comprehensive evaluation method for a wireless charging magnetic coupler. Background Art

[0002] In today's digital and intelligent society, wireless charging technology, with its unique convenience and safety, is becoming a revolutionary solution for the energy supply of electronic devices, especially in the fields of consumer electronics, electric vehicles and industrial automation. The application of wireless charging technology is becoming more and more extensive. As the core of the wireless charging system, the performance of the magnetic coupler is directly related to the efficiency, reliability and safety of the entire charging system. Although wireless charging technology has brought significant convenience, its widespread application has also brought a series of challenges, especially how to comprehensively evaluate and optimize the performance of magnetic couplers. Since the wireless charging system involves complex electromagnetic field interactions, its coupling strength, stability and reliability have become key factors that must be carefully considered in design and implementation.

[0003] However, current research and market evaluation standards and methods often target a specific single performance indicator and lack a comprehensive assessment of the multi-faceted performance of magnetic couplers in practical applications.

[0004] Incomplete evaluation will bring the following disadvantages and adverse effects on technology:

[0005] On the one hand, performance optimization is insufficient: if only focusing on a single performance indicator, other important factors may be ignored, resulting in poor overall performance of the magnetic coupler in actual applications. Failure to fully evaluate may lead to instability or failure under certain working conditions (such as when the coil is dynamically offset), affecting the reliability and safety of the system.

[0006] On the other hand, design limitations: the lack of comprehensive performance evaluation data support during the design process may lead to a suboptimal design solution and the inability to fully realize the potential of the magnetic coupler. The product performance is not comprehensive enough, which may put it at a disadvantage in the market and make it difficult to meet the diverse needs of users. In addition, the lack of comprehensive evaluation index parameters will lead to deviations in the research and development direction, and it is impossible to determine the advantages of changing the coupler design.

[0007] This limitation is not conducive to the further development and optimization of the technology, and also affects the promotion and application of wireless charging technology. Summary of the invention

[0008] Based on this, it is necessary to propose a comprehensive evaluation method for wireless charging magnetic couplers to address the above problems, to achieve a comprehensive evaluation of the various performance aspects of wireless charging magnetic couplers in practical applications, and to promote the development of radio technology.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] A comprehensive evaluation method for a wireless charging magnetic coupler, comprising:

[0011] S1: obtaining a maximum mutual inductance, a maximum anti-offset distance and a mutual inductance standard deviation through a first acquisition channel, wherein the maximum mutual inductance and the mutual inductance standard deviation have a functional relationship, and the three performance indicators of the maximum mutual inductance, the maximum anti-offset distance and the mutual inductance standard deviation jointly determine the performance indicators of the magnetic coupler;

[0012] S2: Calculating the weights corresponding to the maximum mutual inductance, the maximum anti-offset distance and the mutual inductance standard deviation according to the maximum value of the magnetic coupler performance index;

[0013] S3: Obtain the maximum mutual inductance and the maximum anti-offset distance through the second acquisition channel to obtain the performance index of the magnetic coupler.

[0014] In one embodiment, the first equation k=α*c%M is also included. max +β*d%x max +γ*e%σ(M), where c%, d% and e% are constants, and M max is the maximum mutual inductance, the x max is the maximum anti-offset distance, σ(M) is the mutual inductance standard deviation, corresponding to the coupling strength, anti-offset capability and magnetic field uniformity of the magnetic coupler, respectively, and the maximum mutual inductance M max and the mutual inductance standard deviation σ(M) have a functional relationship, k is a magnetic coupler performance index, and the maximum mutual inductance M max , Maximum anti-offset distance x max The three performance indicators of the mutual inductance standard deviation σ(M) jointly determine the magnetic coupler performance indicator k. The value range of k is between 0 and 1. The closer it is to the maximum value 1, the better the magnetic coupling.

[0015] In one embodiment, S1 further includes: obtaining a known quantity M1 by finite element simulation max and x1 max , and then calculate the constant c%M1 max 、d%x1 max and e%σ(M)1;

[0016] The S2 also includes: substituting the maximum value k=1 corresponding to the magnetic coupling into the first equation as a constant to obtain the second equation: c%M1 max α+d%x1 max β+e%σ(M)1γ=1, and calculate the three known quantities c%M1 max 、d%x1 maxThe weights α1, β1 and γ1 corresponding to e%σ(M)1 are taken as known quantities, and the third equation is obtained: k3=α1c%M max +β1d%x max +γ1e%σ(M), in the third equation, α1c%, β1d%, γ1e% are constants, M max 、x max , σ(M) is the independent variable, k3 is the dependent variable;

[0017] The S3 also includes: obtaining M2 by actual measurement max and x2 max And substitute into the third equation to calculate the k3 value.

[0018] In one embodiment, the maximum mutual inductance M max The functional relationship between the mutual inductance standard deviation σ(M) is The Δx is the offset distance, M (average) 0 to x max The average mutual inductance of the magnetic coupler.

[0019] In one embodiment, at least three groups of M are obtained by finite element simulation. max 、x max and σ(M), and then obtain at least 3 groups of c%M max 、d%x max and e%σ(M), substitute into the second equation to obtain a set of three-variable linear equations, calculate the corresponding weights α, β and γ and use them as known quantities to obtain the third equation.

[0020] In one embodiment, the method further includes obtaining the maximum mutual inductance Mmax, the maximum anti-offset distance xmax and the mutual inductance standard deviation σ(M) of the three groups of magnetic couplers by actual measurement, and substituting them into the third equation to calculate the k value.

[0021] In one embodiment, the M max 、x max and σ(M) constrain each other and cannot reach the maximum value at the same time.

[0022] In one embodiment, the three performance indicators are selected as c%, d% and e% of the optimal value respectively.

[0023] In one embodiment, the c% is 50%-95%, the d% is 50%-95%, and the e% is 105%-300%.

[0024] In one embodiment, the maximum anti-offset distance x max The criterion for judgment is that the mutual inductance fluctuation of the magnetic coupler does not exceed ±5% compared with when no offset occurs.

[0025] The present invention proposes a comprehensive evaluation method for wireless charging magnetic coupler, using the first equation k = α * c% M max +β*d%x max +γ*e%σ(M) includes three indicators to judge the magnetic coupler. The three indicator data obtained through the first acquisition channel are substituted into the first equation to calculate the weight. Then the three indicators are obtained through the second channel to calculate the magnetic coupling performance K value. It has the following advantages:

[0026] ① The comprehensive evaluation method of the magnetic coupler of the present invention comprehensively considers the coupling strength, anti-offset capability and magnetic field uniformity, and can comprehensively evaluate the performance of the magnetic coupler. The weights of the evaluation indicators are flexibly adjustable to meet different magnetic coupler evaluation requirements.

[0027] The proposed comprehensive performance evaluation method solves the limitations of single indicator evaluation in traditional evaluation methods by comprehensively considering multiple key performance indicators, such as coupling strength, anti-offset capability, and magnetic field uniformity. This method not only optimizes the overall performance of the magnetic coupler, but also improves the reliability and efficiency of the system. Through scientific evaluation criteria, coupler designers and developers can more accurately identify and optimize the design of magnetic couplers to ensure their stability and safety under various working conditions. In addition, this comprehensive evaluation method provides a scientific basis for the application of new technologies and new materials, ensuring the optimal performance of each performance indicator in the overall system. Ultimately, users will experience more efficient and stable wireless charging devices that meet diverse needs.

[0028] ② The comprehensive evaluation method for magnetic couplers of the present invention has the advantages of simple calculation process and direct expression form, and also helps to provide a scientific basis for the design and optimization of magnetic couplers. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] in:

[0031] Figure 1 It is a flow chart of a comprehensive evaluation method of a wireless charging magnetic coupler according to the present invention; DETAILED DESCRIPTION

[0032] In order to facilitate the understanding of the present invention, the present invention is described in more detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that when an element is described as "connected" to another element, it can be directly on another element, or there can be one or more centered elements therebetween. The terms "upper", "lower", "left", "right", "upper end", "lower end", "top" and "bottom" used in this specification indicate an orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0033] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0034] In order to solve the problem that the evaluation standards and methods of magnetic couplers in scientific research and the market in the existing technology only target a specific single performance indicator, lack of comprehensive evaluation of various aspects of the performance of magnetic couplers in practical applications, which is not conducive to the advancement of radio technology, a comprehensive evaluation method for wireless charging magnetic couplers is proposed.

[0035] The following will be combined Figure 1 A comprehensive evaluation method for a wireless charging magnetic coupler provided in an embodiment of the present invention is described in detail.

[0036] See also Figure 1 , Figure 1 It is a flow chart of a comprehensive evaluation method for a wireless charging magnetic coupler described in the present invention.

[0037] A comprehensive evaluation method for a wireless charging magnetic coupler, comprising:

[0038] S1: obtaining a maximum mutual inductance, a maximum anti-offset distance and a mutual inductance standard deviation through a first acquisition channel, wherein the maximum mutual inductance and the mutual inductance standard deviation have a functional relationship, and the three performance indicators of the maximum mutual inductance, the maximum anti-offset distance and the mutual inductance standard deviation jointly determine the performance indicators of the magnetic coupler;

[0039] S2: Calculating the weights corresponding to the maximum mutual inductance, the maximum anti-offset distance and the mutual inductance standard deviation according to the maximum value of the magnetic coupler performance index;

[0040] S3: Obtain the maximum mutual inductance and the maximum anti-offset distance through the second acquisition channel to obtain the performance index of the magnetic coupler.

[0041] Specifically, a magnetic coupler, also known as a magnetic coupler or a permanent magnet transmission device, is a device that uses magnetic force to achieve power transmission between two objects. It is usually composed of a copper rotor, a permanent magnet rotor and a controller. The rotational power of the motor is transmitted to the impeller through magnetic force, avoiding the common shaft seal leakage problem in traditional pumps. This device uses the force between magnets to transmit the torque of the active system to the follower system, achieving coupling without mechanical connection. It is widely used in radio communications, wireless charging, power transmission and sensor technology. The current research and market evaluation standards for magnetic couplers are often only for a single performance indicator, and there is a lack of comprehensive evaluation methods for magnetic couplers. For example, there are only evaluation standards for the maximum mutual inductance, or only judgment standards for the maximum anti-offset distance.

[0042] The factors that affect the magnetic coupling performance include the rate of change of magnetic flux, the factors that affect the rate of change of magnetic flux include mutual inductance and the maximum distance between the two coils, and the mutual inductance is divided into the value of the maximum mutual inductance and the standard deviation of the mutual inductance. Therefore, it is necessary to set parameters according to the maximum mutual inductance, the maximum anti-offset distance and the standard deviation of the mutual inductance and their relationship in combination with the actual situation, and calculate the variables corresponding to the above three factors as a comprehensive evaluation of the performance of the wireless charging magnetic coupler.

[0043] There are three factors for comprehensive evaluation of the performance of wireless charging magnetic couplers: maximum mutual inductance, maximum anti-offset distance and mutual inductance standard deviation. The above three factors have their own corresponding constants and weights. The three constants are determined by the physical properties of the wireless charging coupler. The maximum mutual inductance, maximum anti-offset distance and mutual inductance standard deviation are also determined by the physical properties of the wireless charging coupler. The weights are set manually after calculation.

[0044] Different couplers have different physical properties. Therefore, for different couplers, their parameters are fixed values. The maximum mutual inductance and maximum anti-offset distance can be obtained through two different acquisition channels. The maximum mutual inductance, maximum anti-offset distance and mutual inductance standard deviation are obtained through the first channel. The weight value is calculated corresponding to the maximum value of the magnetic coupler performance index. The weight represents the optimal weight corresponding to the magnetic coupler when the magnetic property is in the best state. The calculated optimal weight group is used as the existing parameter of the magnetic coupler, which is the inherent physical property of the coupler. Then, the maximum mutual inductance, maximum anti-offset distance and mutual inductance standard deviation are obtained again through the second acquisition channel, and the magnetic coupler performance index can be calculated.

[0045] By considering multiple factors in the comprehensive evaluation method of magnetic couplers, people can not only have a deeper understanding and optimize the performance of magnetic couplers, but also take into account other important factors of magnetic couplers to improve the overall performance of magnetic couplers in practical applications; it also helps to provide a scientific basis for the design and optimization of magnetic couplers.

[0046] In one embodiment, the first equation k=α*c%M is also included. max +β*d%x max +γ*e%σ(M), where c%, d% and e% are constants, and M max is the maximum mutual inductance, the x max is the maximum anti-offset distance, σ(M) is the mutual inductance standard deviation, corresponding to the coupling strength, anti-offset capability and magnetic field uniformity of the magnetic coupler, respectively, and the maximum mutual inductance M max and the mutual inductance standard deviation σ(M) have a functional relationship, k is a magnetic coupler performance index, and the maximum mutual inductance M max , Maximum anti-offset distance x max The three performance indicators of the mutual inductance standard deviation σ(M) jointly determine the magnetic coupler performance indicator k. The value range of k is between 0 and 1. The closer it is to the maximum value 1, the better the magnetic coupling.

[0047] Specifically, the factors that affect the magnetic coupling performance are the rate of change of magnetic flux, the factors that affect the rate of change of magnetic flux are mutual inductance and the maximum distance between the two coils, and the mutual inductance is divided into the value of the maximum mutual inductance and the standard deviation of the mutual inductance, so it is necessary to design a formula including the maximum mutual inductance M. max , Maximum anti-offset distance x max And the mutual inductance standard deviation σ(M), and set the parameters according to the actual situation, and add the variables corresponding to the above three factors as a comprehensive evaluation of the performance of the wireless charging magnetic coupler.

[0048] Formula k = α * c% M max +β*d%x max +γ*e%σ(M) is used to comprehensively evaluate the performance of the wireless charging magnetic coupler. The formula contains 4 terms, one of which has a term on one side, which represents the k of the wireless charging magnetic coupler performance, and the other three terms correspond to the maximum mutual inductance M. max , Maximum anti-offset distance x max , mutual inductance standard deviation σ(M), each term corresponds to constant c%, constant d%, constant e%, weight α, weight β, weight γ, the three constants are determined by the physical properties of the wireless charging coupler, the maximum mutual inductance M max , Maximum anti-offset distance x max The mutual inductance standard deviation σ(M) is also determined by the physical properties of the wireless charging coupler, and the weights α, β, and γ are artificially set after calculation.

[0049] The idea of ​​this formula is that different couplers have different physical properties, so for different couplers, their c%M max 、d%x max and e%σ(M) are fixed values, and the maximum mutual inductance M can be obtained through two different acquisition channelsmax and the maximum anti-offset distance x max , use the first channel to obtain the maximum mutual inductance M max and the maximum anti-offset distance x max After that, through the maximum mutual inductance M max The mutual inductance standard deviation σ(M) is calculated by the function relationship, and the maximum value 1 corresponding to the magnetic coupler performance index k is substituted into the formula as a constant to calculate the weights α, β and γ. The values ​​of α, β and γ at this time represent the optimal weights corresponding to the best magnetic properties of the magnetic coupler. The calculated set of weights is used as the constant of the magnetic coupler, that is, at this time, for the magnetic coupler, the constant c%, constant d%, constant e%, weight α, weight β and weight γ on the same side of the equation are constants, and the maximum mutual inductance M max , Maximum anti-offset distance x max , mutual inductance standard deviation σ(M) are three independent variables, which are functions of k. Then, through the second acquisition channel, the three independent variables are obtained and the k value is calculated.

[0050] By considering multiple factors in the comprehensive evaluation method of magnetic couplers, people can not only have a deeper understanding and optimize the performance of magnetic couplers, but also take into account other important factors of magnetic couplers to improve the overall performance of magnetic couplers in practical applications; it can also provide comprehensive performance evaluation data support during the design process, providing a scientific basis for the design and optimization of magnetic couplers.

[0051] In one embodiment, S1 further includes: obtaining a known quantity M1 by finite element simulation max and x1 max , and then calculate the constant c%M1 max 、d%x1 max and e%σ(M)1;

[0052] The S2 also includes: substituting the maximum value k=1 corresponding to the magnetic coupling into the first equation as a constant to obtain the second equation: c%M1 max α+d%x1 max β+e%σ(M)1γ=1, and calculate the three known quantities c%M1 max 、d%x1 max The weights α1, β1 and γ1 corresponding to e%σ(M)1 are taken as known quantities, and the third equation is obtained: k3=α1c%M max +β1d% xmax +γ1e%σ(M), in the third equation, α1c%, β1d%, γ1e% are constants, M max 、x max , σ(M) is the independent variable, k3 is the dependent variable;

[0053] The S3 also includes: obtaining M2 by actual measurementmax and x2 max And substitute into the third equation to calculate the k3 value.

[0054] Specifically, the first acquisition channel uses finite element simulation, which is not an experiment in the traditional sense. Finite element simulation is a numerical analysis method based on computer information processing. It uses the principles of mathematical mechanics and computer technology to conduct quantitative analysis of complex engineering problems and scientific research through numerical discretization technology to obtain approximate solutions. By constructing mathematical models and algorithms to simulate real-world physical phenomena and behaviors, although finite element simulation can simulate various situations under experimental conditions, it is essentially a calculation method, which is different from the traditional method of verifying theories and designs through physical experiments. Therefore, finite element simulation is used as the first acquisition channel for magnetic coupling effects that need to consider multiple physical fields.

[0055] Obtaining the known quantity M1 through finite element simulation max and x1 max , and then calculate the constant c%M1 max 、d%x1 max and e%σ(M)1;

[0056] The constant c%M1 max 、d%x1 max Substitute e%σ(M)1 into the first equation k=α*c%M max +β*d%x max +γ*e%σ(M), which is used to derive the second equation, and the purpose of the second equation is to calculate the weight α, the weight β, and the weight γ.

[0057] The idea of ​​this formula is that different couplers have their own inherent physical properties, so for different couplers, their c%M max 、d%x max and e%σ(M) are definite values,

[0058] When the known quantity M1 is obtained through finite element simulation test max and x1 max , through the maximum mutual inductance M max The mutual inductance standard deviation σ(M) is calculated by the function relationship.

[0059] The maximum value 1, c%M1 corresponding to the magnetic coupler performance index k max 、d%x1 max Substituting % and e%σ(M)1 as constants into the first equation, we can derive the second equation:

[0060] c%M1 max α+d%x1 max β+e%σ(M)1γ=1,

[0061] The second equation is a three-variable first-order equation. The weight α, weight β, and weight γ are unknown variables, which represent the optimal weights corresponding to the best magnetic properties of the magnetic coupler. Substitute multiple sets of data to calculate the weights α1, β1, and γ1. The calculated set of weights is used as the constant of the magnetic coupler to derive the third equation:

[0062] k3=α1c%M max +β1d%x max +γ1e%σ(M),

[0063] That is, at this time, for the magnetic coupler, the six constants c%, constant d%, constant e%, weight α1, weight β1, and weight γ1 on the same side of the equation are constants. Their physical meaning is that at this time, weight α1, weight β1, and weight γ1 correspond to the coefficients when the magnetic coupler has the best performance, and the maximum mutual inductance M max , Maximum anti-offset distance x max , mutual inductance standard deviation σ(M) are three independent variables, which are functions of k.

[0064] Then, through the second acquisition channel different from the first acquisition channel, three independent variables are obtained by experimental measurement, substituted into the third equation and the k value is calculated. The operation process of the experimental measurement includes: the main experimental instruments are an impedance analyzer and a ruler. After the coupler is built, it is matched with the ruler. On the transmitter, the receiver is shaken and moved in all directions from left to right, up to down, front to back, and at the same time, the mutual inductance changes of the transmitter and receiver tested on the disk analyzer are observed. If the change is within the preset range, it is determined to be a stable state.

[0065] For example:

[0066] Step 1-Determine c%Mmax, d%xmax, e%σ(M): Determine c%=85%, d%=75% and e%=200%, determine the maximum mutual inductance Mmax and the maximum anti-offset distance xmax of the magnetic coupler in combination with finite element simulation, and calculate the mutual inductance standard deviation σ(M) in combination with formula (2);

[0067] Step 2-Calculate α, β and γ: According to 85% Mmax, 75% xmax, 200% σ(M) and the constraint k=1, calculate the corresponding weights of a set of three: α=0.015, β=0.01 and γ=-1;

[0068] Step 3-Calculate k value: The relevant parameters of the three groups of magnetic couplers are measured, and the maximum mutual inductance Mmax, maximum anti-offset distance xmax and mutual inductance standard deviation σ(M) of the three groups of couplers are substituted into formula (1) respectively. The normalized comprehensive evaluation index k of the three groups of magnetic couplers is calculated to be 0.975, 0.995 and 0.94 respectively. By comparing the comprehensive evaluation indexes, the magnetic coupler designed with parameter 2 has better performance.

[0069] Finite element simulation is an important part of modern simulation technology, rather than an experiment in the traditional sense. Through the finite element analysis method, a multi-physical field coupling model is established to analyze the interaction and influence between different physical fields. It is convenient and quick to obtain the weights of the three factors that affect the coupling effect of the magnetic coupler, and then substitute specific data through experimental measurement (i.e. actual measurement) to calculate the magnetic coupler performance index K. The comprehensive evaluation method of magnetic couplers considering multiple factors not only enables people to have a deeper understanding and optimize the performance of magnetic couplers, but also helps to provide a scientific basis for the design and optimization of magnetic couplers.

[0070] In one embodiment, the maximum mutual inductance M max The functional relationship between the mutual inductance standard deviation σ(M) is The Δx is the offset distance, M (average) 0 to x max The average mutual inductance of the magnetic coupler.

[0071] Specifically, the standard deviation is used to measure the degree of dispersion of a set of data, that is, the degree of deviation of the data points from the average value. The larger the standard deviation, the more dispersed the data points; the smaller the standard deviation, the more concentrated the data points. In magnetic coupling, the standard deviation is used to measure the stability of mutual inductance. The larger the standard deviation, the more unstable the mutual inductance.

[0072] When the maximum mutual inductance M is obtained max After that, the mutual inductance standard deviation σ(M) can be calculated using this functional relationship.

[0073] The factors that affect the magnetic coupling performance include the rate of change of magnetic flux, the factors that affect the rate of change of magnetic flux include mutual inductance and the maximum distance between the two coils. Mutual inductance is divided into the value of maximum mutual inductance and the standard deviation of mutual inductance. Obtaining the mutual inductance standard deviation σ(M) by calculation is conducive to taking into account various factors of the magnetic coupler, which helps to provide a scientific basis for the design and optimization of the magnetic coupler.

[0074] In one embodiment, at least three groups of M are obtained by finite element simulation. max 、x max and σ(M), and then obtain at least 3 groups of c%M max 、d%x maxand e%σ(M), substitute into the second equation to obtain a set of three-variable linear equations, calculate the corresponding weights α, β and γ and use them as known quantities to obtain the third equation.

[0075] Specifically, due to the second equation c%M1 max α+d%x1 max β+e%σ(M)1γ=1 is a three-variable linear method with three unknowns α, β and γ. Therefore, the process of calculating the three unknowns is the process of solving the equation. It is necessary to obtain at least 3 sets of coefficients c%M1 max 、d%x1 max , e%σ(M)1.

[0076] In one embodiment, it also includes experimentally measuring and obtaining the maximum mutual inductance Mmax, the maximum anti-offset distance xmax and the mutual inductance standard deviation σ(M) of the three groups of magnetic couplers, and substituting them into the third equation respectively to calculate the k value.

[0077] Specifically, for any coupler, its maximum mutual inductance and maximum anti-offset distance are inherent properties, which can be obtained through experimental measurement of detection instruments. max and x2 max After that, by substituting into the function The mutual inductance standard deviation σ(M) is calculated, the data measured in the three experiments are substituted into the third equation, and the magnetic coupler performance index k is calculated.

[0078] The acquisition method includes a controlled variable method, for example, the mutual inductance fluctuation range of the receiver of the magnetic coupler is controlled within the range of ±5%, and the receiver is randomly moved within this range to obtain the maximum movement distance of a receiver, which is the maximum anti-offset distance xmax; similarly, the distance between the transmitter and the receiver of the coupler is controlled within a preset distance, and the receiver is shaken and moved in various directions from left to right, up to down, front to back, and within this distance, while observing the change in mutual inductance between the transmitter and the receiver tested on the disk analyzer, the maximum value Mmax.

[0079] In one embodiment, Mmax, xmax and σ(M) restrict each other and cannot reach the maximum value at the same time.

[0080] Set the moving range of the receiver within a specific distance, and then measure the maximum value of its mutual inductance within this distance. One of the factors affecting mutual inductance includes magnetic flux. When the receiver moves and becomes farther away from the transmitter, the magnetic flux between the receiver and the transmitter decreases, which in turn reduces the mutual inductance. Therefore, the mutual inductance is negatively correlated with the offset distance. The maximum mutual inductance Mmax and the maximum anti-offset distance xmax cannot reach the maximum value at the same time. σ(M) and Mmax are negatively correlated, so σ(M) and xmax cannot reach the maximum value at the same time.

[0081] In one embodiment, the three performance indicators are selected as c%, d% and e% of the maximum value respectively.

[0082] Specifically, the data is obtained through multiple experiments.

[0083] In one embodiment, the c% is 50%-95%, the d% is 50%-95%, and the e% is 105%-300%.

[0084] Specifically, the data is obtained through experiments. In S1, we first need to obtain c%, d%, and e% through multiple experiments and use them as constants in the first equation. Since Mmax, xmax, and σ(M) are mutually constrained and cannot reach their maximum values ​​at the same time, we need to conduct repeated experiments on individual variables to obtain their maximum values. The experimental data are shown in the following table, where d represents the moving distance of the receiving coil of the magnetic coupler relative to the transmitting coil, and r represents the moving distance of the receiving coil of the magnetic coupler relative to the transmitting coil. s Indicates the outer diameter of the receiving coil, N p1 Indicates the number of turns of the outer ring of the transmitting coil of the magnetic coupler, N p2 Indicates the number of turns of the inner coil of the magnetic coupler transmitting coil, r p1 Represents the outer diameter of the outer ring of the transmitting coil of the magnetic coupler, r p2 Represents the outer diameter of the inner ring of the magnetic coupler transmitting coil.

[0085]

[0086] In one embodiment, the maximum anti-offset distance x max The criterion for judgment is that the mutual inductance fluctuation of the magnetic coupler does not exceed ±5% compared with when no offset occurs.

[0087] Specifically, when the mutual inductance fluctuation range of the magnetic coupler is between ±5%, various performances of the magnetic coupler remain stable.

[0088] The application scenarios of the present invention include but are not limited to the following:

[0089] Scenario 1: Electric vehicle wireless charging system: In the wireless charging system of electric vehicles, the performance of the coupler directly affects the charging efficiency and safety. Aspects that need to be evaluated include:

[0090] ① Charging efficiency: the energy transfer efficiency of the coupler at different distances and alignment angles.

[0091] Thermal management: The temperature rise of the coupler during long charging and its impact on battery life.

[0092] ② Anti-offset capability: whether the coupler can work stably under offset conditions.

[0093] Technical effect:

[0094] Improve charging efficiency: Ensure efficient energy transfer at different distances and locations by fully evaluating coupling strength and anti-drift capability.

[0095] Enhanced safety: Reduce interference with surrounding equipment and overheating risks by evaluating magnetic field uniformity and thermal management performance.

[0096] Improve reliability: Through environmental adaptability and durability evaluation, ensure stability in various climatic conditions and durability in long-term use.

[0097] Issues resolved:

[0098] Existing technologies usually only focus on a single indicator, such as coupling strength, ignoring performance under offset conditions and environmental adaptability, resulting in insufficient charging efficiency and safety.

[0099] Through comprehensive evaluation, stability issues and insufficient environmental adaptability under offset conditions can be considered and resolved in advance during the design process to ensure the overall performance of the system.

[0100] Scenario 2: Smartphone wireless charging base:

[0101] In a wireless charging dock for smartphones, the performance of the coupler affects the user experience and device safety. Aspects that need to be evaluated include:

[0102] Charging efficiency: directly related to the coupling strength of the coupler.

[0103] Alignment accuracy: The impact of improper placement of the phone on charging efficiency.

[0104] Electromagnetic interference: The degree of interference the coupler causes to surrounding electronic equipment when operating.

[0105] Both scenarios involve multi-faceted performance evaluation of wireless charging couplers to ensure their effectiveness and safety in practical applications. When developing wireless charging products in relevant scenarios, the proposed comprehensive evaluation method can be used to quantitatively evaluate the comprehensive performance of the developed wireless charging coupler products, thereby improving the performance of wireless charging products in the corresponding scenarios.

[0106] Technical Effect:

[0107] Optimize user experience: By evaluating charging efficiency and alignment accuracy, it ensures that the charging process can proceed efficiently even in the case of slight misalignment.

[0108] Reduce electromagnetic interference: Ensure that the impact on surrounding electronic equipment is minimized through comprehensive assessment of electromagnetic interference.

[0109] Issues resolved:

[0110] Existing technologies often ignore the comprehensive evaluation of alignment accuracy and electromagnetic interference, which requires users to precisely align their phones when placing them, affecting the user experience.

[0111] Through comprehensive performance evaluation, problems such as insufficient alignment accuracy and electromagnetic interference can be considered and solved in advance during design, improving user experience and device safety.

[0112] The beneficial effects of the present invention are as follows: In view of the fact that the evaluation standards and methods for magnetic couplers in current research and the market are often aimed at a specific single performance indicator, the present invention has the following advantages by considering multiple factors in the comprehensive evaluation method of magnetic couplers:

[0113] ① The comprehensive evaluation method of the magnetic coupler of the present invention comprehensively considers the coupling strength, anti-offset capability and magnetic field uniformity, and can comprehensively evaluate the performance of the magnetic coupler. The weights of the evaluation indicators are flexibly adjustable to meet different magnetic coupler evaluation requirements.

[0114] More comprehensive performance optimization: taking into account other important factors to improve the overall performance of the magnetic coupler in actual applications. Comprehensive evaluation can avoid instability or failure under certain operating conditions (such as when the coil is dynamically offset), thereby enhancing the reliability and safety of the system.

[0115] ② The comprehensive evaluation method for magnetic couplers of the present invention has the advantages of simple calculation process and direct expression form, and also helps to provide a scientific basis for the design and optimization of magnetic couplers.

[0116] Comprehensive performance evaluation data support can be provided during the design process to optimize the design scheme and give full play to the potential of magnetic couplers. This will make the product have comprehensive performance, be in an advantageous position in the market, and meet the diverse needs of users. In addition, comprehensive evaluation index parameters will guide the research and development direction of scientific researchers and determine the advantages of changing the coupler design. This will be conducive to the further development and optimization of radio technology.

[0117] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may also be combined, the steps may be implemented in any order, and there are many other changes in different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity. Although the present invention is described in detail with reference to the above embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the above embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A comprehensive evaluation method for a wireless charging magnetic coupler, characterized in that: include: S1: obtaining a maximum mutual inductance, a maximum anti-offset distance and a mutual inductance standard deviation through a first acquisition channel, wherein the maximum mutual inductance and the mutual inductance standard deviation have a functional relationship, and the three performance indicators of the maximum mutual inductance, the maximum anti-offset distance and the mutual inductance standard deviation jointly determine the performance indicators of the magnetic coupler; S2: Calculating the weights corresponding to the maximum mutual inductance, the maximum anti-offset distance and the mutual inductance standard deviation according to the maximum value of the magnetic coupler performance index; S3: Obtain the maximum mutual inductance and the maximum anti-offset distance through the second acquisition channel to obtain the performance index of the magnetic coupler.

2. A comprehensive evaluation method for wireless charging magnetic coupler according to claim 1, characterized in that: It also includes the first equation k=α*c%M max +β*d%x max +γ*e%σ(M), where c%, d% and e% are constants, and M max is the maximum mutual inductance, the x max is the maximum anti-offset distance, σ(M) is the mutual inductance standard deviation, corresponding to the coupling strength, anti-offset capability and magnetic field uniformity of the magnetic coupler, respectively, and the maximum mutual inductance M max and the mutual inductance standard deviation σ(M) have a functional relationship, k is a magnetic coupler performance index, and the maximum mutual inductance M max , Maximum anti-offset distance x max The three performance indicators of the mutual inductance standard deviation σ(M) jointly determine the magnetic coupler performance indicator k. The value range of k is between 0 and 1. The closer it is to the maximum value 1, the better the magnetic coupling.

3. A comprehensive evaluation method for wireless charging magnetic coupler according to claim 2, characterized in that: The S1 also includes: obtaining a known quantity M1 through finite element simulation max and x 1max , and then calculate the constant c%M1 max 、d%x1 max and e%σ(M)1; The S2 also includes: substituting the maximum value k=1 corresponding to the magnetic coupling into the first equation as a constant to obtain the second equation: c%M1 max α+d%x1 max β+e%σ(M)1γ=1, and calculate the three known quantities c%M1 max 、d%x1 max The weights α1, β1 and γ1 corresponding to e%σ(M)1 are taken as known quantities, and the third equation is obtained: k3=α1c%M max +β1d%x max +γ1e%σ(M), in the third equation, α1c%, β1d%, γ1e% are constants, M max 、x max , σ(M) is the independent variable, k3 is the dependent variable; The S3 also includes: obtaining M2 by actual measurement max and x2 max And substitute into the third equation to calculate the k3 value.

4. A comprehensive evaluation method for wireless charging magnetic coupler according to claim 3, characterized in that: The maximum mutual inductance M max The functional relationship between the mutual inductance standard deviation σ(M) is The Δx is the offset distance, M (average) 0 to x max The average mutual inductance of the magnetic coupler.

5. A comprehensive evaluation method for wireless charging magnetic coupler according to claim 4, characterized in that: Obtain at least 3 groups of M through finite element simulation max 、x max and σ(M), and then obtain at least 3 groups of c%M max 、d%x max and e%σ(M), substitute into the second equation to obtain a set of three-variable linear equations, calculate the corresponding weights α, β and γ and use them as known quantities to obtain the third equation.

6. A comprehensive evaluation method for wireless charging magnetic coupler according to claim 5, characterized in that: It also includes obtaining the maximum mutual inductance Mmax, the maximum anti-offset distance xmax and the mutual inductance standard deviation σ(M) of the three groups of magnetic couplers by actual measurement, and substituting them into the third equation respectively to calculate the k value.

7. A comprehensive evaluation method for wireless charging magnetic coupler according to claim 1, characterized in that: The M max 、x max and σ(M) constrain each other and cannot reach the maximum value at the same time.

8. A comprehensive evaluation method for wireless charging magnetic coupler according to claim 7, characterized in that: The three performance indicators are selected as c%, d% and e% of the optimal values ​​respectively.

9. A comprehensive evaluation method for wireless charging magnetic coupler according to claim 8, characterized in that: The c% is 50%-95%, the d% is 50%-95%, and the e% is 105%-300%.

10. A comprehensive evaluation method for wireless charging magnetic coupler according to claim 1, characterized in that: The maximum anti-offset distance x max The criterion for judgment is that the mutual inductance fluctuation of the magnetic coupler does not exceed ±5% compared with when no offset occurs.

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