A method for calculating the parasitic capacitance of coupled toroidal inductors

Abstract

The present application relates to a method for calculating the parasitic capacitance of a coupled toroidal inductor, and belongs to the field of electronic information technology. Obtain the inner diameter of the wire, the outer diameter of the wire, the length of a single-turn winding, the relative dielectric constant of the insulation layer, the distance between two adjacent turns of the coil, and the number of coil turns of the target coupled toroidal inductor; use a parabola to simulate the electric field line path between the coils, construct the electric field line path equation between two adjacent turns of the coils, and calculate the air gap parasitic capacitance between two adjacent turns of the coil based on the electric field line path equation, the length of a single-turn winding, and the outer diameter of the wire; calculate the parasitic capacitance between two adjacent turns of the coil based on the parasitic capacitance of the insulation layer and the parasitic capacitance of the air gap; calculate the total parasitic capacitance of the target coupled toroidal inductor based on the parasitic capacitance between two adjacent turns of the coil, the parasitic capacitance between the coil and the magnetic core, and the number of coil turns. The electric field line path equation constructed in the present application is closer to the actual electric field line path, which improves the accuracy of the calculation results of the parasitic capacitance of the coupled toroidal inductor.

Description

Technical Field

[0001] The present application relates to the field of electronic information technology, and in particular to a method for calculating the parasitic capacitance of a coupled toroidal inductor. Background Art

[0002] As the operating frequency of the switching power converter increases, the EMI noise level generated in its circuit is also getting higher and higher. The level of EMI noise depends largely on the magnetic components in the switching power converter, that is, the parasitic capacitance of the inductor. Therefore, in order to minimize EMI noise, it is very important to calculate the parasitic capacitance of the inductor during the design stage of the inductor and provide direction for the design optimization of the component based on the size of the parasitic capacitance.

[0003] For coupled toroidal inductors, their parasitic capacitance is closely related to the turn-to-turn capacitance (parasitic capacitance between adjacent coils), and the turn-to-turn capacitance includes the insulation layer capacitance and the air gap capacitance between two adjacent turns of the coils. In the prior art, when calculating the air gap capacitance between two adjacent turns of the coupled toroidal inductor, the electric field line path between the coils is directly approximated as a straight line path, but in fact the electric field line path between the coils is not a straight line, so the air gap capacitance calculated using the prior art is not accurate, resulting in a large error between the parasitic capacitance value of the coupled toroidal inductor finally calculated and the actual value; in addition, the distance between two adjacent turns of the coil will affect the size of the air gap capacitance, and the prior art does not consider the distance between two adjacent coils when constructing the electric field line path, so the existing calculation method can only be used to roughly calculate the air gap capacitance of the inductor with a distance of 0 between two adjacent turns of the coil (i.e. tightly wound), and cannot calculate the air gap capacitance of the inductor that is not tightly wound.

[0004] In summary, the existing method for calculating the parasitic capacitance of coupled toroidal inductors has low accuracy, the calculated parasitic capacitance has a large error with the actual value, and cannot be used to calculate the parasitic capacitance of non-tightly wound inductors, thus failing to provide accurate data support for component design optimization. Summary of the invention

[0005] To this end, the technical problem to be solved by the present application is to overcome the problems of low accuracy in the prior art method for calculating the parasitic capacitance of a coupled toroidal inductor, large errors between the calculated parasitic capacitance and the actual value, and the inability to be used to calculate the parasitic capacitance of a non-tightly wound inductor, thereby failing to provide accurate data support for component design optimization.

[0006] In order to solve the above technical problems, the present application provides a method for calculating the parasitic capacitance of a coupled toroidal inductor, comprising:

[0007] Obtain the inner diameter of the wire, the outer diameter of the wire, the length of a single-turn winding, the relative dielectric constant of the insulation layer, the distance between two adjacent turns of the coil, and the number of turns of the coil of the target coupled toroidal inductor;

[0008] Using a parabola equation to simulate the path of the electric field lines between two adjacent turns of the coil, constructing an equation for the path of the electric field lines between the two adjacent turns of the coil based on the distance between the two adjacent turns of the coil and the parabola equation, and calculating the air gap parasitic capacitance between the two adjacent turns of the coil based on the equation for the path of the electric field lines between the two adjacent turns of the coil, the length of the single turn winding and the outer diameter of the conductor;

[0009] Calculating the parasitic capacitance between two adjacent turns of the coil based on the air gap parasitic capacitance between the two adjacent turns of the coil and the insulation layer parasitic capacitance between the two adjacent turns of the coil;

[0010] The total parasitic capacitance of the target coupled toroidal inductor is calculated based on the parasitic capacitance between the two adjacent turns of the coil, the parasitic capacitance between the coil and the magnetic core, and the number of turns of the coil.

[0011] In one embodiment of the present application, the parabola equation is:

[0012]

[0013] Among them, y is the ordinate of the parabola equation, x is the abscissa of the parabola equation, S is the distance between two adjacent turns of the coil, D0 is the outer diameter of the wire, and θ is the inner angle between the intersection of the parabola and the x-axis;

[0014] The electric field line path equation between the two adjacent turns of coils constructed based on the distance between the two adjacent turns of coils and the parabola equation is:

[0015]

[0016] Among them, x(θ) is the electric field line path equation between two adjacent turns of the coil,

[0017] In one embodiment of the present application, the calculation formula of the air gap parasitic capacitance between two adjacent turns of the coil is:

[0018]

[0019] Among them, C g is the parasitic capacitance of the air gap between two adjacent turns of the coil, ε0 is the dielectric constant of vacuum, l T is the length of a single turn winding.

[0020] In one embodiment of the present application, the calculation formula of the parasitic capacitance of the insulation layer between two adjacent turns of the coil is:

[0021]

[0022] Among them, C t-ti is the parasitic capacitance of the insulation layer between two adjacent turns of the coil, ε r is the relative dielectric constant of the insulating layer, ε0 is the dielectric constant of vacuum, l T is the length of a single turn winding, D i is the inner diameter of the wire, and D0 is the outer diameter of the wire.

[0023] In one embodiment of the present application, the calculation formula of the parasitic capacitance between two adjacent turns of the coil is:

[0024]

[0025] Among them, C t-t is the parasitic capacitance between two adjacent turns of the coil, dC t-ti is the infinitesimal value of the parasitic capacitance of the insulation layer between two adjacent turns of the coil, dC g is the infinitesimal element of the parasitic capacitance of the air gap between two adjacent turns of the coil, S is the distance between two adjacent turns of the coil, D0 is the outer diameter of the wire, ε r is the relative dielectric constant of the insulating layer, ε0 is the dielectric constant of vacuum, l T is the length of a single turn winding, D i is the inner diameter of the wire.

[0026] In one embodiment of the present application, when the target coupled toroidal inductor has a magnetic core, the parasitic capacitance between the coil and the magnetic core is calculated based on the inner diameter of the wire, the outer diameter of the wire, the length of the single-turn winding and the relative dielectric constant of the insulation layer.

[0027] In one embodiment of the present application, the calculation formula of the parasitic capacitance between the coil and the magnetic core is:

[0028]

[0029] Among them, C tc is the parasitic capacitance between the coil and the core, D0 is the outer diameter of the wire, ε r is the relative dielectric constant of the insulating layer, ε0 is the dielectric constant of vacuum, l T is the length of a single turn winding, D i is the inner diameter of the wire.

[0030] In one embodiment of the present application, when the distance between the two adjacent turns of the coil is 0, the calculation formula of the total parasitic capacitance of the target coupled toroidal inductor is:

[0031]

[0032] Among them, C AB (N) is the total parasitic capacitance of the target coupled toroidal inductor, N is the number of turns of the coil, C t-t is the parasitic capacitance between two adjacent turns of the coil, C AB (N-2) is the total parasitic capacitance when the number of turns of the target coupled toroidal inductor is N-2 turns.

[0033] In one embodiment of the present application, when the distance between the two adjacent turns of the coil is not 0, the calculation formula of the total parasitic capacitance of the target coupled toroidal inductor is:

[0034]

[0035] Among them, C AB (N) is the total parasitic capacitance of the target coupled toroidal inductor, N is the number of turns of the coil, C t-t is the parasitic capacitance between two adjacent turns of the coil, C AB (N-2) is the total parasitic capacitance when the number of turns of the target coupled toroidal inductor is N-2 turns.

[0036] In one embodiment of the present application, when the target coupled toroidal inductor does not have a magnetic core, the parasitic capacitance between the coil and the magnetic core is 0, and the calculation formula of the total parasitic capacitance of the target coupled toroidal inductor is:

[0037]

[0038] Among them, C AB (N) is the total parasitic capacitance of the target coupled toroidal inductor, N is the number of turns of the coil, C t-t is the parasitic capacitance between two adjacent turns of the coil.

[0039] The method for calculating the parasitic capacitance of a coupled toroidal inductor provided in the present application uses a parabolic equation to simulate the electric field line path between two adjacent turns of a coil, and then constructs an electric field line path equation between two adjacent turns of the coil based on the distance between the two adjacent turns of the coil and the parabolic equation; calculates the air gap parasitic capacitance between the two adjacent turns of the coil based on the electric field line path equation, the length of a single turn winding, and the outer diameter of the coil; calculates the parasitic capacitance between the two adjacent turns of the coil based on the parasitic capacitance of the insulation layer between the two adjacent turns of the coil and the parasitic capacitance of the air gap between the two adjacent turns of the coil; finally, calculates the total parasitic capacitance of the coupled toroidal inductor based on the number of coil turns of the coupled toroidal inductor, the parasitic capacitance between the two adjacent turns of the coil, and the parasitic capacitance between the coil and the magnetic core. When calculating the air gap parasitic capacitance, the present application uses a parabola to simulate the electric field line path between the coils, so that the constructed electric field line path equation is closer to the real electric field line path, so that the air gap capacitance calculated based on the electric field line path equation is closer to the actual value, thereby improving the accuracy of the calculation result of the parasitic capacitance of the coupled toroidal inductor; in addition, the present application also considers the distance between two adjacent turns of the coil when constructing the electric field line path equation. Therefore, the method for calculating the parasitic capacitance of the coupled toroidal inductor provided by the present application can be used to calculate the air gap parasitic capacitance of a tightly wound coupled toroidal inductor, and can also be used to calculate the air gap parasitic capacitance of a non-tightly wound coupled toroidal inductor. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to make the content of this application easier to understand, the following is a further detailed description of this application based on the specific embodiments of this application and in conjunction with the accompanying drawings, wherein

[0041] Figure 1 A flow chart of a method for calculating the parasitic capacitance of a coupled toroidal inductor provided in this application;

[0042] Figure 2 A schematic diagram of the path of electric field lines between coils of a coupled toroidal inductor in the prior art;

[0043] Figure 3 Schematic diagram of tightly wound and non-tightly wound coupled toroidal inductors;

[0044] Figure 4 A schematic diagram of a simulation of the path of the electric field lines in the air gap between two adjacent turns of the coupled toroidal inductor choke provided in the present application;

[0045] Figure 5 A schematic diagram of the path of the electric field lines in the air gap between two adjacent turns of the coupled toroidal inductor choke provided in the present application.

[0046] Figure 6 Schematic diagram of the capacitance distribution in the coupled toroidal inductor choke. DETAILED DESCRIPTION

[0047] The present application is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present application and implement it, but the embodiments are not intended to limit the present application.

[0048] See also Figure 1 As shown, Figure 1 A flow chart of a method for calculating the parasitic capacitance of a coupled toroidal inductor provided in this application, the method specifically comprising:

[0049] S10: obtaining the inner diameter of the wire, the outer diameter of the wire, the length of a single-turn winding, the relative dielectric constant of the insulation layer, the distance between two adjacent turns of the coil, and the number of turns of the coil of the target coupled toroidal inductor;

[0050] Specifically, the coil is wound by a wire, which is made by wrapping an insulating layer around the outside of a copper wire or an aluminum wire. Therefore, the outer diameter of the wire refers to the diameter of the entire wire including the insulating layer, and the inner diameter of the wire refers to the diameter of the copper wire or the aluminum wire.

[0051] S20: using a parabola equation to simulate the path of the electric field lines between two adjacent turns of the coil, constructing the path equation of the electric field lines between two adjacent turns of the coil based on the distance between the two adjacent turns of the coil and the parabola equation, and calculating the air gap parasitic capacitance between the two adjacent turns of the coil based on the path equation of the electric field lines between the two adjacent turns of the coil, the length of a single turn winding and the outer diameter of the conductor;

[0052] S30: calculating the parasitic capacitance between two adjacent turns of the coil based on the parasitic capacitance of the air gap between the two adjacent turns of the coil and the parasitic capacitance of the insulation layer between the two adjacent turns of the coil;

[0053] S40: Calculate the total parasitic capacitance of the target coupled toroidal inductor based on the parasitic capacitance between two adjacent turns of the coil, the parasitic capacitance between the coil and the magnetic core, and the number of turns of the coil.

[0054] When calculating the air gap parasitic capacitance, the present application uses a parabola to simulate the electric field line path between the coils, so that the constructed electric field line path equation is closer to the real electric field line path, so that the air gap capacitance calculated based on the electric field line path equation is closer to the actual value, thereby improving the accuracy of the calculation result of the parasitic capacitance of the coupled toroidal inductor; in addition, the present application also considers the distance between two adjacent turns of the coil when constructing the electric field line path equation. Therefore, using the coupled toroidal inductor parasitic capacitance calculation method provided by the present application, it is possible to calculate the air gap parasitic capacitance of a tightly wound coupled toroidal inductor, and it is also possible to calculate the air gap parasitic capacitance of a non-tightly wound coupled toroidal inductor.

[0055] Specifically, in step S20, the embodiment of the present application equates the air gap parasitic capacitance between two adjacent turns of the coil to a parallel plate capacitor, since the capacitance C of the parallel plate capacitor is calculated as: Wherein, s is the plate area, and x is the distance between the plates. In the present embodiment, the distance between the plates is equivalent to the path of the electric field lines on the air gap between two adjacent turns of the coil. Therefore, to calculate the parasitic capacitance of the air gap between two adjacent turns of the coil, it is necessary to construct an equation for the path of the electric field lines on the air gap between two adjacent turns of the coil.

[0056] In the prior art, when calculating the air gap parasitic capacitance between two adjacent turns of a coil, a straight line path is used to simulate the path of the electric field line, such as Figure 2 As shown, the electric field line path equation constructed is x(θ)=2R w0 (1-cosθ)=D w0 (1-cosθ), since the electric field line path used by it deviates from the actual path, there is a large error between the calculated air gap parasitic capacitance between two adjacent turns of the coil and the actual value.

[0057] In addition, Figure 3 As shown in the figure, the distances between the windings of different coupled toroidal inductors are also different. Figure 2 It can also be seen that in the prior art, when constructing the electric field line path equation, it is constructed based on zero distance between turns (i.e., tight winding), and the influence of the distance between two adjacent turns of the coil on the parasitic capacitance is not considered, which will also reduce the accuracy of the calculation results.

[0058] See also Figure 4 , Figure 4 This is a schematic diagram of the electric field line path between two turns of coils simulated using Maxwell finite element analysis software. It can be seen from the figure that the electric field line path between two adjacent turns of coils is not a straight line path, but a parabolic path. Therefore, in order to more accurately reflect the electric field line path between two adjacent turns of coils and make the calculated air gap parasitic capacitance more accurate, this application uses a parabolic equation to simulate the electric field line path between two adjacent turns of coils.

[0059] Specifically, Figure 5 As shown in the figure, the two groups of concentric circles are cross-sectional schematic diagrams of the conductors of two adjacent turns of coils wound around the top of the magnetic core. For each group of concentric circles, the diameter of the inner circle is the inner diameter of the conductor, the diameter of the outer circle is the outer diameter of the conductor, and the distance S between the two groups of concentric circles is the distance between two adjacent turns of coils.

[0060] In this embodiment, a rectangular coordinate system is constructed with the connecting line of the centers of the two concentric circles as the x-axis, the midpoint of the connecting line as the origin, and the vertical upward direction as the y-axis;

[0061] Furthermore, a parabola is used to simulate the electric field line path x(θ) in the air gap between two adjacent turns of the coil. The parabola intersects the x-axis at points x1 and x2. In addition, the parabola also passes through the point (x0, y0), where

[0062] Based on the above coordinate points, it can be determined that the electric field line path x(θ) satisfies the parabola y:

[0063]

[0064] Substituting the point (x0, y0) into the above parabola equation, we get Furthermore, the parabola equation y in step S30 can be expressed as:

[0065]

[0066] Among them, y is the ordinate of the parabola equation, x is the abscissa of the parabola equation, S is the distance between two adjacent turns of the coil, D0 is the outer diameter of the wire, and θ is the inner angle between the intersection of the parabola and the x-axis;

[0067] Therefore, the path of the electric field lines between two adjacent turns of the coil is:

[0068]

[0069] Integrating the above formula:

[0070]

[0071] Among them, but

[0072] in,

[0073] therefore,

[0074]

[0075] Based on the above derivation process, the electric field line path equation between two adjacent turns of the coil constructed in step S20 is:

[0076]

[0077] Among them, x(θ) is the electric field line path equation between two adjacent turns of the coil, S is the distance between two adjacent turns of the coil, and D0 is the outer diameter of the wire.

[0078] Furthermore, the calculation formula of the air gap parasitic capacitance between two adjacent turns of the coil in step S20 is:

[0079]

[0080] Among them, C g is the parasitic capacitance of the air gap between two adjacent turns of the coil, ε0 is the dielectric constant of vacuum, l T is the length of a single turn winding.

[0081] Specifically, the embodiment of the present application simulates the parasitic capacitance of the insulating layer between two adjacent turns of the coil as a cylindrical capacitance, and the total capacitance C of the insulating layer of each turn of the coil is in for:

[0082]

[0083] Among them, ε r is the relative dielectric constant of the insulating layer, ε0 is the dielectric constant of vacuum, l T is the length of a single turn winding, D0 is the outer diameter of the wire, D i is the inner diameter of the wire.

[0084] Furthermore, the insulation layer capacitance C corresponding to each coil turn angle θ θ for:

[0085]

[0086] The parasitic capacitance at an angle θ between the insulation layers of two adjacent turns of the coil is the insulation layer capacitance C corresponding to the angle θ of the two coils. θ The concatenation value is:

[0087]

[0088] Based on the above derivation process, the calculation formula of the parasitic capacitance of the insulation layer between two adjacent turns of the coil is:

[0089]

[0090] Among them, C t-ti is the parasitic capacitance of the insulation layer between two adjacent turns of the coil, ε r is the relative dielectric constant of the insulating layer, ε0 is the dielectric constant of vacuum, l T is the length of a single turn winding, D i is the inner diameter of the wire, and D0 is the outer diameter of the wire.

[0091] Specifically, based on the above-mentioned parasitic capacitance of the insulating layer and the parasitic capacitance of the air gap between two adjacent turns of the coil, the calculation formula of the parasitic capacitance between two adjacent turns of the coil in step S30 is:

[0092]

[0093] Among them, C t-t is the parasitic capacitance between two adjacent turns of the coil, dC t-ti is the infinitesimal value of the parasitic capacitance of the insulation layer between two adjacent turns of the coil, dC g is the infinitesimal element of the parasitic capacitance of the air gap between two adjacent turns of the coil, S is the distance between two adjacent turns of the coil, D0 is the outer diameter of the wire, ε r is the relative dielectric constant of the insulating layer, ε0 is the dielectric constant of vacuum, l T is the length of a single turn winding, D i is the inner diameter of the wire.

[0094] Specifically, since the parasitic capacitance calculation method provided in the present application takes into account the influence of the distance between two adjacent turns of the coil on the parasitic capacitance, the method can be used to calculate the parasitic capacitance between two adjacent turns of the coupled toroidal inductor that are tightly wound (the distance between two adjacent turns of the coil S=0), and can also be used to calculate the parasitic capacitance between two adjacent turns of the coupled toroidal inductor that are not tightly wound (the distance between two adjacent turns of the coil S≠0):

[0095] For a tightly wound coupled toroidal inductor, the parasitic capacitance between two adjacent turns of the coil is calculated as:

[0096]

[0097] Among them, since the coil is tightly wound, the distance between two adjacent turns of the coil is S = 0, so,

[0098]

[0099] For a non-tightly wound coupled toroidal inductor, the formula for calculating the parasitic capacitance between two adjacent turns of the coil is:

[0100]

[0101] Among them, since the coil is not tightly wound, the distance S between two adjacent turns of the coil is ≠ 0, so,

[0102]

[0103] Optionally, since some coupled toroidal inductors have a magnetic core, the coils are wound around the magnetic core in turns. For such coupled toroidal inductors, the total parasitic capacitance includes the parasitic capacitance between the coils and the magnetic core in addition to the parasitic capacitance between the coils, such as Figure 6 As shown in Figure C tcIt is the parasitic capacitance between the coil and the magnetic core. Therefore, in addition to the parasitic capacitance between two adjacent turns of the coil calculated above, it is also necessary to calculate the parasitic capacitance between the coil and the magnetic core based on the inner diameter of the wire, the outer diameter of the wire, the length of a single turn winding and the relative dielectric constant of the insulation layer;

[0104] Specifically, since the parasitic capacitance between the coil and the magnetic core is independent of the distance between the coils, the distance between the coils does not need to be considered when calculating the parasitic capacitance between the coil and the magnetic core. Based on this, in an embodiment of the present application, the calculation formula for the parasitic capacitance between the coil and the magnetic core is:

[0105]

[0106] Among them, C tc is the parasitic capacitance between the coil and the core, D0 is the outer diameter of the wire, ε r is the relative dielectric constant of the insulating layer, ε0 is the dielectric constant of vacuum, l T is the length of a single turn winding, D i is the inner diameter of the wire.

[0107] Furthermore, for a target coupled toroidal inductor having a magnetic core, when the distance S between two adjacent turns of the coil in the target coupled toroidal inductor is 0, the calculation formula of the total parasitic capacitance is:

[0108]

[0109] Among them, C AB (N) is the total parasitic capacitance of the target coupled toroidal inductor, N is the number of turns of the coil, C t-t is the parasitic capacitance between two adjacent turns of the coil, C AB (N-2) is the total parasitic capacitance when the number of turns of the target coupled toroidal inductor is N-2 turns.

[0110] When the distance S between two adjacent turns of the target coupled toroidal inductor is not 0, the calculation formula for its total generated capacitance is:

[0111]

[0112] Among them, C AB (N) is the total parasitic capacitance of the target coupled toroidal inductor, N is the number of turns of the coil, C t-t is the parasitic capacitance between two adjacent turns of the coil, C AB (N-2) is the total parasitic capacitance when the number of turns of the target coupled toroidal inductor is N-2 turns.

[0113] Optionally, some coupled toroidal inductors do not have a magnetic core. For such coupled toroidal inductors, the total parasitic capacitance is the parasitic capacitance between the coils. Therefore, the total parasitic capacitance can be calculated based on the parasitic capacitance between two adjacent turns of the coil and the number of coil turns calculated according to the above embodiment.

[0114] Specifically, for the target coupled toroidal inductor without a magnetic core, the total parasitic capacitance is calculated as:

[0115]

[0116] Among them, C AB (N) is the total parasitic capacitance of the target coupled toroidal inductor, N is the number of turns of the coil, C t-t is the parasitic capacitance between two adjacent turns of the coil.

[0117] The method for calculating the parasitic capacitance of a coupled toroidal inductor provided in an embodiment of the present application can not only be used to calculate the self-capacitance and self-resonant frequency of the coupled toroidal inductor, but also help reduce the EMI level in power electronic circuits and help solve electromagnetic compatibility problems. In addition, the total parasitic capacitance of the coupled toroidal inductor calculated using the method provided in the present application is more accurate, and the inductor designed by the designer based on the calculation result can meet the working requirements of the circuit, thereby increasing the accuracy of the design stage and avoiding repeated design procedures before production. In addition, the method provided in the present application is based on the geometric dimensions and materials of the coupled toroidal inductor. It only needs to obtain the core size and material, winding size and material of the coupled toroidal inductor to accurately calculate its parasitic capacitance. It is simple and time-saving, and does not require the use of an impedance analyzer and complex finite element analysis software.

[0118] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0119] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0120] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0121] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0122] Obviously, the above embodiments are merely examples for the purpose of clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection created by this application.

Claims

1. A method for calculating the parasitic capacitance of a coupled toroidal inductor, characterized in that: include: Obtain the inner diameter of the wire, the outer diameter of the wire, the length of a single-turn winding, the relative dielectric constant of the insulation layer, the distance between two adjacent turns of the coil, and the number of turns of the coil of the target coupled toroidal inductor; Using the parabola equation Simulate the path of the electric field lines between two adjacent turns of the coil, and construct the path equation of the electric field lines between the two adjacent turns of the coil based on the distance between the two adjacent turns of the coil and the parabola equation ;in, is the ordinate of the parabola equation, is the abscissa of the parabola equation, is the distance between two adjacent turns of the coil, is the outer diameter of the wire, is the inner angle between the parabola and the x-axis; is the electric field line path equation between two adjacent turns of the coil, , ; Calculating the air gap parasitic capacitance between the two adjacent turns of the coil based on the electric field line path equation between the two adjacent turns of the coil, the length of the single turn winding and the outer diameter of the wire; Calculating the parasitic capacitance between two adjacent turns of the coil based on the air gap parasitic capacitance between the two adjacent turns of the coil and the insulation layer parasitic capacitance between the two adjacent turns of the coil; The total parasitic capacitance of the target coupled toroidal inductor is calculated based on the parasitic capacitance between the two adjacent turns of the coil, the parasitic capacitance between the coil and the magnetic core, and the number of turns of the coil.

2. The method for calculating the parasitic capacitance of a coupled toroidal inductor according to claim 1, wherein: The calculation formula of the air gap parasitic capacitance between two adjacent turns of the coil is: ， in, is the parasitic capacitance of the air gap between two adjacent turns of the coil, is the dielectric constant of vacuum, is the length of a single turn winding.

3. The method for calculating the parasitic capacitance of a coupled toroidal inductor according to claim 1, wherein: The calculation formula of the parasitic capacitance of the insulation layer between two adjacent turns of the coil is: ， in, is the parasitic capacitance of the insulation layer between two adjacent turns of the coil, is the relative dielectric constant of the insulating layer, is the dielectric constant of vacuum, is the length of a single turn winding, is the inner diameter of the wire, is the outer diameter of the wire.

4. The method for calculating the parasitic capacitance of a coupled toroidal inductor according to claim 1, wherein: The calculation formula of the parasitic capacitance between two adjacent turns of the coil is: ， in, is the parasitic capacitance between two adjacent turns of the coil, is the infinitesimal value of the parasitic capacitance of the insulation layer between two adjacent turns of the coil, is the infinitesimal element of the parasitic capacitance of the air gap between two adjacent turns of the coil, , , is the distance between two adjacent turns of the coil, is the outer diameter of the wire, is the relative dielectric constant of the insulating layer, is the dielectric constant of vacuum, is the length of a single turn winding, is the inner diameter of the wire.

5. The method for calculating the parasitic capacitance of a coupled toroidal inductor according to claim 1, wherein: When the target coupled toroidal inductor has a magnetic core, the parasitic capacitance between the coil and the magnetic core is calculated based on the inner diameter of the wire, the outer diameter of the wire, the length of the single-turn winding, and the relative dielectric constant of the insulation layer.

6. The method for calculating the parasitic capacitance of a coupled toroidal inductor according to claim 5, characterized in that: The calculation formula of the parasitic capacitance between the coil and the magnetic core is: ， in, is the parasitic capacitance between the coil and the core, , , is the outer diameter of the wire, is the relative dielectric constant of the insulating layer, is the dielectric constant of vacuum, is the length of a single turn winding, is the inner diameter of the wire.

7. The method for calculating the parasitic capacitance of a coupled toroidal inductor according to claim 6, wherein: When the distance between the two adjacent turns of the coil is 0, the calculation formula of the total parasitic capacitance of the target coupled toroidal inductor is: ， in, is the total parasitic capacitance of the target coupled toroidal inductor, is the number of coil turns, is the parasitic capacitance between two adjacent turns of the coil, When the number of turns of the target coupled toroidal inductor is The total parasitic capacitance during the turns.

8. The method for calculating the parasitic capacitance of a coupled toroidal inductor according to claim 6, wherein: When the distance between the two adjacent turns of the coil is not 0, the calculation formula of the total parasitic capacitance of the target coupled toroidal inductor is: ， in, is the total parasitic capacitance of the target coupled toroidal inductor, is the number of coil turns, is the parasitic capacitance between two adjacent turns of the coil, When the number of turns of the target coupled toroidal inductor is The total parasitic capacitance during the turns.

9. The method for calculating the parasitic capacitance of a coupled toroidal inductor according to claim 1, wherein: When the target coupled toroidal inductor does not have a magnetic core, the parasitic capacitance between the coil and the magnetic core is 0, and the calculation formula of the total parasitic capacitance of the target coupled toroidal inductor is: ， in, is the total parasitic capacitance of the target coupled toroidal inductor, is the number of coil turns, is the parasitic capacitance between two adjacent turns of the coil.

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