A design method and system for a rotary tuned inductor

Abstract

The application discloses a design method and system of a rotary tuning inductor, and belongs to the field of electronic components. The application establishes a rotary tuning inductor analytical model, and obtains an optimal parameter combination of an inductor stator and a rotor through optimization solution, so that time and materials consumed for meeting the inductance value range through physical winding in the inductor design stage are greatly reduced, inductor design efficiency is improved, and the problems of complicated and complex rotary tuning inductor design process and lack of theoretical guidance are solved.

Description

Technical Field

[0001] This invention belongs to the field of electronic components, and more specifically, relates to a design method and system for a rotary tuned inductor. Background Technology

[0002] To achieve maximum power transmission in communication systems, tuned inductors are needed to transform the equivalent impedance of the load. High- and medium-power communication systems typically operate in high-power, high-voltage, and high-current environments, requiring the use of electric actuators to control the inductors. Currently, tuned inductors in high-power communication systems are mainly divided into two categories: linear tuned inductors and rotary tuned inductors. Linear tuned inductors consist of a small solenoid connected in series inside a large solenoid. The mutual inductance between the two solenoids is changed by the linear movement of the small solenoid in the axial direction, achieving continuous adjustment of the inductance. However, this type of tuned inductor has disadvantages such as large size and weight, and its tuning range is relatively small, making it unsuitable for integration. Rotary tuned inductors consist of a stator and a rotor. A rotor is connected in series inside the stator, and the mutual inductance is changed by controlling the rotation of the internal rotor with a motor, achieving continuous adjustment of the inductance. Under the same volume conditions, the tuning range of a rotary tuned inductor is larger than that of a linear tuned inductor, and it has the advantages of small size and light weight.

[0003] Currently, research on rotary tuned inductors is limited, and there is a lack of systematic theoretical guidance for their design. The current method of repeatedly winding rotary tuned inductors using an iterative approach suffers from material waste and a lengthy design cycle. To save on raw materials and design time, it is necessary to establish an analytical model of rotary tuned inductors to provide a theoretical basis for their design. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a design method and system for rotary tuned inductors. The purpose is to establish an analytical model for rotary tuned inductors, thereby overcoming the current limitations of cumbersome and complex design processes lacking theoretical guidance. The method directly obtains the design parameters that best approximate the inductance range of the tuned inductor through optimization, saving design time and material consumption.

[0005] To achieve the above objectives, this invention provides a design method for a rotary tuned inductor. Firstly, an analytical model of the rotary tuned inductor is proposed, the specific model of which is as follows:

[0006] A rotary tuned inductor consists of a stator and a rotor, both made of circular toroidal coils with all toroidal centers coaxial. The rotor is connected in series inside the stator, and includes m turns of coil, while the stator includes n turns of coil. Therefore, this analytical model can be analyzed based on the coaxial circular toroidal coils.

[0007] Mutual inductance formula for coaxial circular coil model:

[0008]

[0009] Among them, M ij For the mutual inductance between rings i and j, R i Let R be the radius of the annulus i. j Let i be the radius of the ring j, 1≤i,j≤m+n, h be the distance between the two rings, and K and E be the complete elliptic integrals, which can be determined by looking up the complete elliptic integral table.

[0010] The coil spacing h is divided into two cases. When the two coils are distributed on both sides of the rotating bearing of the rotary tuned inductor, the calculation formula is as follows:

[0011] h=t×Δr+(t-1)×2r+2R bearing

[0012] In the formula, t represents the sum of the number of turns of the two coils and the coil between the two coils, r is the radius of the conductor, Δr is the coil spacing, and R... bearing The radius of the rotating bearing.

[0013] When the two coils are located on the same side of the rotating bearing, the calculation formula is:

[0014] h = (t-1) × (Δr + 2r)

[0015] Self-inductance formula for a circular coil model:

[0016]

[0017] Where R is the radius of the ring, μ0 is the permeability of free space, and μ is the permeability of the coil material.

[0018] A rotary tuned inductor has an m-turn rotor coil and an n-turn stator coil, generating a mutual inductance matrix M of order (m+n). The matrix expression is as follows:

[0019]

[0020] Among them, the diagonal elements of matrix M are M ii For the self-inductance of the toroid, the remaining elements are M. ij There is mutual inductance between the rings. L1 is the rotor self-inductance matrix of a rotary tuned inductor; L2 is the self-inductance matrix of the rotating tuned inductor stator; M 12 and M 21 All are rotating tuned inductors with mutual inductance matrices between the stator and rotor.

[0021] Formula for calculating the inductance of a rotary tuned inductor:

[0022]

[0023] Among them, L sum L1 is the rotor self-inductance, L2 is the stator self-inductance, and M is the value of the rotary tuned inductor. 12 M 21 This represents the mutual inductance between the rotor and stator. The M matrix is ​​a symmetric matrix, therefore M... 12 =M 21 .

[0024] The inductance range is an important parameter for evaluating the performance of a rotary tuned inductor. When the inductor rotation angle is 0°, both the stator and rotor currents are in the counterclockwise direction, and the mutual inductance between the stator and rotor is M. 12 and M 21 When the value is positive, the maximum inductance of the rotary tuned inductor is L. max When the inductor rotates 180°, the stator current direction remains unchanged, while the rotor current changes to a clockwise direction, and the mutual inductance M between the stator and rotor increases. 12 and M 21 When the value is negative, the maximum inductance of the rotary tuned inductor is L. min Therefore, by simplifying the rotation process of the rotary tuned inductor and analyzing the 0° and 180° cases, the important parameter of the inductance range can be obtained. The maximum and minimum inductance values ​​of the rotary tuned inductor can be written as follows:

[0025] L max =L1+L2+2M 12-0

[0026] L min =L1+L2+2M 12-180

[0027] Among them, M 12-0 M represents the mutual inductance between the stator and rotor when the inductor rotates 0°. 12-180 The mutual inductance value between the stator and rotor when the inductor rotates 180°.

[0028] As can be seen from the above, M 12 The absolute values ​​at 0° and 180° are equal and opposite to each other, i.e., M 12-0 =-M 12-180 Therefore, the inductance range of a rotary tuned inductor is:

[0029]

[0030] To save material consumption and design time for rotary tuned inductors, the rotary tuned inductor design method provided by this invention includes:

[0031] S1, Input the desired maximum inductance value L max-in and minimum inductance value Lmin-in Input the basic inductor parameters: wire radius, wire spacing, rotary bearing radius, and maximum inductor radius. The radius of the circular wire is determined based on the operating current of the rotary tuned inductor. Input the number of search loops and the inductor threshold.

[0032] S2 generates a set of random variables, including: rotor radius, stator radius, number of rotor layers, number of turns per rotor layer, number of stator layers, and number of turns per stator layer;

[0033] S3 determines whether the parameters of the random variable set satisfy the constraints. If they do, proceed to S4; otherwise, return to S2. The constraints are:

[0034] (1) The number of rotor layers, the number of turns per rotor layer, the number of stator layers, and the number of turns per stator layer are all natural numbers;

[0035] (2) The number of turns in the upper layer is less than or equal to the number of turns in the lower layer;

[0036] (3) During the rotation of the inductor, the rotor and the stator do not collide;

[0037] (4) The stator meets the volume restriction requirements after the circular coil is wound;

[0038] S4, calculate the actual maximum inductance value L from this set of random variables. max and minimum inductance value L min Then, the objective function of this set of variable parameters is solved;

[0039] S5, determine whether the objective function of the set of variable parameters is the historical best. If it is the historical best, store the set of parameters and proceed to S6; otherwise, return to S2.

[0040] S6, determine whether the inductance threshold requirement has been met. If it has, output the set of parameters; otherwise, proceed to S7.

[0041] S7: Determine if the search loop has been completed. If it has, output the parameters corresponding to the historical best objective function; otherwise, return to S2.

[0042] The present invention also provides a design system for a rotary tuned inductor, comprising: a computer-readable storage medium and a processor;

[0043] The computer-readable storage medium is used to store executable instructions;

[0044] The processor is used to read executable instructions stored in the computer-readable storage medium and execute the above-described design method for a rotary tuned inductor.

[0045] Compared with the prior art, the above-described technical solutions conceived in this invention can achieve the following beneficial effects:

[0046] This invention provides an analytical model and design method for a rotary tuned inductor. An analytical model for a rotary tuned inductor is established. The optimal parameter combination of the inductor stator and rotor is obtained through optimization solution, which greatly reduces the time and material consumed by physical winding to meet the inductance range in the inductor design stage, improves the efficiency of inductor design, and solves the shortcomings of the current rotary tuned inductor design process being cumbersome, complex and lacking theoretical guidance. Attached Figure Description

[0047] Figure 1(a) and Figure 1(b) are schematic diagrams of a rotary tuned inductor rotating at 0° and 90°, respectively.

[0048] Figure 2 This is a model diagram of a coaxial circular loop coil;

[0049] Figure 3 This is a schematic diagram of a circular coil;

[0050] Figure 4 This is a flowchart of the design method for a rotary tuned inductor. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0052] As shown in Figures 1(a) and 1(b), a rotary tuned inductor has a fixed external stator and an internal rotating rotor that changes the mutual inductance to achieve continuous adjustment of the inductance. Both the stator and rotor are made of circular coils, and the centers of all the circular coils are coaxial. Therefore, this analytical model can be analyzed based on the coaxial circular coils. The inductance range is an important parameter for evaluating the performance of a rotary tuned inductor. When the inductor rotation angle is 0°, both the stator and rotor currents are counterclockwise, and the mutual inductance between the stator and rotor is M. 12 and M 21 When the value is positive, the maximum inductance of the rotary tuned inductor is L. max When the inductor rotates 180°, the stator current direction remains unchanged, while the rotor current changes to a clockwise direction, and the mutual inductance M between the stator and rotor increases. 12 and M 21 When the value is negative, the maximum inductance of the rotary tuned inductor is L. min Therefore, by simplifying the rotation process of the rotary tuned inductor and analyzing the two cases of 0° and 180°, the inductance range can be obtained.

[0053] This invention provides an analytical model for a rotary tuned inductor, the specific model of which is as follows:

[0054] Coaxial circular coil model as follows Figure 2 As shown, the mutual inductance formula is:

[0055]

[0056] Among them, M ij For the mutual inductance between rings i and j, R i Let R be the radius of the annulus i. j Let be the radius of the ring j, h be the distance between the two rings, and K and E be the complete elliptic integrals, which can be determined by looking up the complete elliptic integral table.

[0057] The coil spacing h is divided into two cases. When the two coils are distributed on both sides of the rotating bearing of the rotary tuned inductor, the calculation formula is as follows:

[0058] h=t×Δr+(t-1)×2r+2R bearing

[0059] In the formula, t represents the sum of the number of turns of the two coils and the coil between the two coils, r is the radius of the conductor, Δr is the coil spacing, and R... bearing The radius of the rotating bearing.

[0060] When the two coils are located on the same side of the rotating bearing, the calculation formula is:

[0061] h = (t-1) × (Δr + 2r)

[0062] A schematic diagram of a circular coil is shown below. Figure 3 As shown, the formula for self-induction is:

[0063]

[0064] Among them, M ii R is the self-inductance, r is the radius of the ring, μ0 is the permeability of free space, and μ is the permeability of the coil material.

[0065] A rotary tuned inductor has an m-turn rotor coil and an n-turn stator coil, generating an m+n order mutual inductance matrix M, expressed as follows:

[0066]

[0067] Among them, the diagonal elements of matrix M are M ii For the self-inductance of the toroid, the remaining elements are M. ij There is mutual inductance between the rings. L1 is the rotor self-inductance matrix of a rotary tuned inductor; L2 is the self-inductance matrix of the rotating tuned inductor stator; M12 and M 21 All are rotating tuned inductors with mutual inductance matrices between the stator and rotor.

[0068] M-matrix and voltage phasor matrix Current phasor matrix The relationship is as follows:

[0069]

[0070] Assuming current vector The expression is:

[0071]

[0072] Since all coils of a rotary tuned inductor are connected in series, the current flowing through each turn is equal, and the total voltage across the inductor is the sum of the voltages across each turn. Therefore:

[0073]

[0074] Therefore, the total voltage across the inductor The expression is:

[0075]

[0076] The formula for calculating the inductance of a rotary tuned inductor is:

[0077]

[0078] Among them, L sum L1 is the rotor self-inductance, L2 is the stator self-inductance, and M is the value of the rotary tuned inductor. 12 M 21 This represents the mutual inductance between the rotor and stator. The M matrix is ​​a symmetric matrix, therefore M... 12 =M 21 .

[0079] The maximum inductance of a rotary tuned inductor at 0° and the minimum inductance at 180° can be written as:

[0080] L max =L1+L2+2M 12-0

[0081] L min =L1+L2+2M 12-180

[0082] Among them, M 12-0 M represents the mutual inductance between the stator and rotor when the inductor rotates 0°. 12-180 The mutual inductance value between the stator and rotor when the inductor rotates 180°.

[0083] As can be seen from the above, M 12 The absolute values ​​at 0° and 180° are equal and opposite to each other, i.e., M 12-0 =-M 12-180 Therefore, the inductance range of a rotary tuned inductor is:

[0084]

[0085] This invention provides a method for designing a rotary tuned inductor, such as... Figure 4 As shown, it includes:

[0086] S1, Input the desired maximum inductance value L max-in and minimum inductance value L min-in Input the basic inductor parameters: wire radius, wire spacing, rotary bearing radius, and maximum inductor radius. The radius of the circular wire is determined based on the operating current of the rotary tuned inductor. Input the number of search loops and the inductor threshold.

[0087] S2 generates a set of random variables, including: rotor radius, stator radius, number of rotor layers, number of turns per rotor layer, number of stator layers, and number of turns per stator layer. There are four constraints in total, including:

[0088] (1) The number of rotor layers, the number of turns per rotor layer, the number of stator layers, and the number of turns per stator layer are all natural numbers;

[0089] (2) The number of turns in the upper layer is less than or equal to the number of turns in the lower layer;

[0090] (3) During the rotation of the inductor, the rotor and the stator do not collide;

[0091] (4) The stator meets the volume restriction requirements after the circular coil is wound.

[0092] S3: Determine whether the set of variable parameters meets the constraints. If the constraints are met, proceed to S4; otherwise, return to S2.

[0093] S4, calculate the actual maximum inductance value L from this set of random variables. max and minimum inductance value L min Then, the objective function for this set of variable parameters is solved:

[0094] target fun=(L max-in -L max ) 2 +(L min-in -L min ) 2

[0095] S5, determine whether the objective function of this set of variable parameters is the historical best. If it is the historical best, store the set of parameters and proceed to S6; otherwise, return to S2.

[0096] S6, determine whether the inductance threshold requirement has been met. If it has, output the set of parameters; otherwise, proceed to S7.

[0097] S7: Determine if the search loop has been completed. If it has, output the parameters corresponding to the historical best objective function; otherwise, return to S2.

[0098] To better verify the analytical model of the rotary tuned inductor provided in this invention, an example is given below:

[0099] This embodiment uses JMAG software for finite element simulation to verify the accuracy of the analytical model of the rotary tuned inductor provided by this invention. In this embodiment, the rotor coil has 16 turns and the stator coil has 16 turns. The analytical model calculation results and the JMAG finite element simulation results are shown in Table 1.

[0100] Table 1 Accuracy of Rotary Tuned Inductor Model

[0101]

[0102] This embodiment verifies the analytical model of a rotary tuned inductor with 16 rotor turns and 16 stator turns. Under this analytical model, the maximum error percentage between the maximum inductance value and the finite element simulation is 2.68%, and the maximum error percentage between the minimum inductance value and the finite element simulation is 2.95%. The comparison results show that the analytical model of the rotary tuned inductor provided by this invention has high accuracy.

[0103] To better verify the rotary tuned inductor design method provided by this invention, the following example is given:

[0104] In this embodiment, the desired maximum inductance value L is set. max-in The minimum inductance value is 5mH, L. min-in The inductance parameters are: 1mH, wire radius 3mm, coil spacing 0, rotary bearing radius 27.5mm, maximum inductance radius 500mm, search cycle count 5000, and inductance threshold 5×10⁻⁶. -9 The final inductor parameters are shown in Table 2. The range of inductance values ​​obtained from the design is shown in Table 3.

[0105] Table 2 Parameters of Rotary Tuning Inductor

[0106]

[0107]

[0108] Table 3. Range of Inductance Values ​​for Rotary Tuning Inductors

[0109]

[0110] The rotary tuned inductor design method provided by this invention yields a set of inductor design parameters. Inductors designed using these parameters have an inductance range of 0.976 mH to 4.940 mH. The maximum inductance error is 1.20%, and the minimum inductance error is 2.41%.

[0111] It is worth noting that the objective function used in this embodiment of the invention aims to minimize the absolute error of the inductance value range, rather than the percentage error. This objective function can be adjusted according to actual needs to meet the design requirements of a rotary tuned inductor.

[0112] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A design method for a rotary tuned inductor, wherein the rotary tuned inductor includes a stator and a rotor, the rotor being connected in series inside the stator, both the stator and the rotor being made of circular toroidal coils wound together, and all the toroidal coils having coaxial centers, the rotor including m turns of coil, and the stator including n turns of coil, characterized in that... Design methods include: S1. Set the desired maximum inductance value L max-in and minimum inductance value L min-in The expression for the m+n order mutual inductance matrix M of the rotary tuned inductor is as follows: (The expression includes the search loop count and the inductance threshold.) Among them, the elements on the diagonal of matrix M M ii For the self-inductance of the toroid, the other elements M ij Mutual inductance between the rings L1 is the self-inductance matrix of the rotary tuned inductor rotor; L2 is the self-inductance matrix of the rotating tuned inductor stator; , M 12 and M 21 All are rotating tuned inductors with mutual inductance matrices between the stator and rotor. S2. Generate a set of random variables, including: rotor radius, stator radius, number of rotor layers, number of turns per rotor layer, number of stator layers, and number of turns per stator layer; S3. Determine whether the parameters of the set of random variables meet the constraints. If they do, proceed to S4; otherwise, return to S2. S4. Calculate the actual maximum inductance value from this set of random variables. L max and minimum inductance value L min Then, the objective function of the set of random variable parameters is solved: ; S5. Determine whether the objective function of the set of random variable parameters is the historical optimum. If it is, store the set of random variable parameters and proceed to S6; otherwise, return to S2. S6. Determine whether the inductance threshold requirement has been met. If it has, output the parameters of the random variable set; otherwise, proceed to S7. S7. Determine if the search loop has been completed. If it has, output the parameters corresponding to the historical best objective function; otherwise, return to S2.

2. The method according to claim 1, characterized in that, Mutual inductance between coaxial circular coils M ij for: Among them, R i Let R be the radius of the annulus i. j Let be the radius of ring j, 1≤i,j≤m+n, h be the distance between the two rings, K and E be the complete elliptic integrals, and μ0 be the permeability of free space.

3. The method according to claim 1, characterized in that, Self-inductance of a coaxial circular coil M ii for: Where R is the coil radius, r is the wire radius, μ0 is the permeability of free space, and μ is the permeability of the coil material.

4. The method according to claim 1, characterized in that, The constraints are: (1) The number of rotor layers, the number of turns per rotor layer, the number of stator layers, and the number of turns per stator layer are all natural numbers; (2) The number of turns in the upper layer is less than or equal to the number of turns in the lower layer; (3) During the rotation of the inductor, the rotor and the stator do not collide; (4) The stator meets the volume restriction requirements after the circular coil is wound.

5. The method according to claim 2, characterized in that, The coil spacing h is divided into two cases. When the two coils are distributed on both sides of the rotating bearing of the rotary tuned inductor, the calculation formula is as follows: When the two coils are located on the same side of the rotating bearing, the calculation formula is: In the formula, t represents the sum of the number of turns of the two coils and the coil between the two coils, r is the radius of the conductor, Δr is the coil spacing, and R... bearing The radius of the rotating bearing.

6. A design system for a rotary tuned inductor, characterized in that, include: Computer-readable storage media and processors; The computer-readable storage medium is used to store executable instructions; The processor is used to read executable instructions stored in the computer-readable storage medium and execute the design method of the rotary tuned inductor according to any one of claims 1 to 5.

Images