Design method and device of high-frequency transformer with round wire type winding based on DC resistance

Abstract

The present invention relates to the technical field of power electronics and power transmission, and in particular to a design method and device for a circular wire type winding high-frequency transformer based on direct current resistance. The design method for the circular wire type winding high-frequency transformer according to the present invention utilizes a direct current resistance calculation model to obtain the direct current resistance of the primary winding, so as to adjust the specification parameters according to the value of the direct current resistance and obtain a transformer meeting the circuit requirements. The acquisition of the direct current resistance calculation model is to equivalent the circular wire type winding to a rectangular wire winding with the same cross-sectional area, use the Poynting vector to calculate the instantaneous power, and through rigorous logical derivation, finally calculate the direct current resistance according to the quotient of the product of the average length of a single-turn winding, the total number of winding layers and the square of the number of turns of the wire in each layer of the winding and the product of the conductivity of the copper winding, the total height of the winding and the width of the p-th layer of the rectangular wire winding. The required parameters do not include the porosity, and the measurement result is not affected by the size of the porosity, and the result is more accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics and electric drive, and particularly to a design method and device for a high-frequency transformer with a round wire type winding based on direct current resistance. Background Art

[0002] As the most commonly used component in a switched-mode power converter, the performance of a high-frequency transformer is particularly important. The performance of the transformer can be analyzed from its equivalent circuit, and the component parameters in the equivalent circuit of the transformer can be calculated from known conditions such as the structure, material, and geometric dimensions of the transformer. As the most important component in the equivalent circuit of the transformer, the calculation method of the direct current resistance has become a research hotspot all the time. The accurate value of the direct current resistance is related to the performance of the entire equivalent circuit of the transformer.

[0003] The winding types of high-frequency transformers are divided into round wire type windings and copper foil type windings. Due to the problem of porosity in round wire type windings, it is much more difficult technically to determine the direct current resistance of round wire type windings than that of copper foil windings.

[0004] In 1966, P.L. Dowell reported the calculation expression of the direct current resistance of a transformer with a round wire type winding where η represents the porosity. The Dowell formula has been used until now and has become the standard formula in the industry. However, since the actual resistance value does not change with the size of the porosity, according to the literature statistics, for the direct current resistance calculated by the above formula, when the porosity is small, the calculation result is relatively accurate, but when the porosity is large, the calculation error is very large. That is to say, the larger the gap between turns of the round wire type winding, the more inaccurate the calculation result. The inaccurate value of the direct current resistance affects the calculation of the direct current resistance in the current winding by the staff, and thus the specification parameters cannot be accurately adjusted according to the direct current resistance, and a transformer that meets the circuit requirements cannot be obtained. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the problem that when designing a transformer based on direct current resistance in the prior art, the calculation of the direct current resistance is affected by the size of the porosity, and the inaccurate calculation result leads to the inability to accurately adjust the specification parameters.

[0006] To solve the above technical problem, the present invention provides a design method for a high-frequency transformer with a round wire type winding based on direct current resistance, including:

[0007] Obtain the specification parameters of the primary winding of the round wire type transformer and the current value of the input direct current, input them into the direct current resistance calculation model, and obtain the value of the direct current resistance generated by the primary winding;

[0008] Adjust the primary winding specification parameters according to the current DC resistance value to obtain a high-frequency transformer that meets the circuit requirements;

[0009] The process of obtaining the DC resistance calculation model includes:

[0010] Equivalent the round wire type winding to be measured to a rectangular wire winding with the same cross-sectional area and pass a DC current through it;

[0011] Based on the current density in the wire of the round wire type winding, according to Ampere's circuital law, obtain the magnetic field strength in the p-th layer of the winding;

[0012] Based on the magnetic field strength expression in the p-th layer of the winding, according to the relationship between the electric field and the current density, obtain the electric field strength in the p-th layer of the winding;

[0013] According to the product of the magnetic field strength and the electric field strength at the outer surface or the inner surface of the p-th layer of the winding, obtain the power flow density at the outer surface or the inner surface of the p-th layer of the winding;

[0014] According to the product of the line integral in the vertical direction of the winding, the average length of a single-turn winding, and the porosity, obtain the differential area of the outer surface or the inner surface of the p-th layer of the winding;

[0015] Calculate the integral area of the Poynting vector on the outer surface or the inner surface of the p-th layer of the winding according to the power flow density and the differential area on the outer surface or the inner surface of the p-th layer of the winding, and obtain the instantaneous power flowing into the outer surface of the p-th layer of the winding or flowing out of the inner surface of the p-th layer of the winding;

[0016] According to the difference between the integral area of the Poynting vector on the outer surface of the p-th layer of the winding and the integral area of the Poynting vector on the inner surface of the p-th layer of the winding, obtain the instantaneous power consumed inside the p-th layer of the winding;

[0017] Sum the instantaneous power consumed inside the m layers of the primary winding to obtain the total instantaneous power equation consumed by the primary winding;

[0018] According to the total instantaneous power equation and the expression of the active power, obtain the DC resistance calculation model:

[0019]

[0020] Among them, lT is the average length of a single-turn winding, m represents the total number of layers of the primary winding, Nl represents the number of turns of the wire in each layer of the winding, σ represents the conductivity of the primary winding, b represents the total height of the primary winding, and h represents the width of the p-th layer of the rectangular wire winding.

[0021] Preferably, the obtaining of the magnetic field strength in the p-th layer of the winding based on the current density in the wire of the round wire type winding according to Ampere's circuital law is expressed by the formula:

[0022]

[0023] Among them, η represents the porosity, J represents the current density, x = 0 / h, h represents the width of the rectangular wire winding of the p-th layer, H0 represents the magnetic field strength on the outer surface of the first-layer primary winding, Nl represents the number of turns of the wire in each layer of the winding, I represents the magnitude of the direct current, and b represents the total height of the primary winding.

[0024] Preferably, the electric field strength in the p-th layer of the winding is obtained based on the expression of the magnetic field strength in the p-th layer of the winding and according to the relationship between the electric field and the current density, including:

[0025] Taking the vertex at the lower left corner of the cross-section of the p-th layer of the winding as the origin and the perimeter in the counterclockwise direction along the cross-section as the integration path According to Maxwell's equations, the line integral of the magnetic field strength H(x) of the p-th layer of the winding along the perimeter of the cross-section of the p-th layer of the winding is the conduction current passing through the total cross-sectional area s of the rectangular wires in the p-th layer of the winding c of the conduction current J represents the current density;

[0026] According to Stokes' theorem, the line integral of the magnetic field strength of the p-th layer of the winding along the perimeter of the cross-section of the p-th layer of the winding is also equal to the surface integral of the curl of the magnetic field on the cross-sectional area s of the p-th layer of the winding The calculated curl of the magnetic field is the product of the porosity and the conduction current density

[0027] Since the conduction current density is the product of the conductivity σ and the electric field strength of the product The calculated curl of the magnetic field is the product of the porosity, conductivity, and electric field strength

[0028] Since the curl of the magnetic field strength can be expressed as The calculated electric field strength in the p-th layer of the winding

[0029] Preferably, the line integral in the vertical direction of the winding The product of the average length lT of a single-turn winding and the porosity η gives the differential area of the outer surface or inner surface of the p-th layer of the winding, and its formula is expressed as:

[0030] The differential area of the inner surface of the p-th layer of the winding

[0031] The differential area of the outer surface of the p-th layer of the winding

[0032] Among them, ax is a unit vector in the horizontal direction.

[0033] Preferably, the power flow density (E z at the outer surface or inner surface of the p-th layer winding is obtained by multiplying the magnetic field strength Ey and the electric field strength H y H z ) x＝h / 0 .

[0034] Preferably, the instantaneous power P consumed inside the p-th layer winding is obtained based on the difference between the integrated area of the Poynting vector on the outer surface of the p-th layer winding and the integrated area of the Poynting vector on the inner surface of the p-th layer winding. p , and its formula is expressed as:

[0035]

[0036] where is the Poynting vector on the outer surface or inner surface of the p-th layer winding, (E y H z ) x＝h / 0 is the power flow density at the outer surface or inner surface of the p-th layer winding, η is the porosity, b is the total height of the primary winding, and l T is the average length of a single-turn winding.

[0037] Preferably, the sum of the instantaneous powers consumed inside the m layers of windings in the primary winding is obtained to get the total instantaneous power equation of the primary winding, which is expressed as:

[0038]

[0039] where lT is the average length of a single-turn winding, m represents the total number of layers of the primary winding, Nl represents the number of turns of the wire in each layer of the winding, I represents the magnitude of the direct current, σ represents the conductivity of the primary winding, b represents the total height of the primary winding, and h represents the width of the rectangular wire winding of the p-th layer.

[0040] Preferably, based on the total instantaneous power equation and the active power expression, a DC resistance calculation model is obtained, and its formula is expressed as:

[0041]

[0042] Preferably, by substituting the porosity into the DC resistance calculation model, another expression of the DC resistance calculation model is obtained, which is:

[0043]

[0044] where the porosity c represents the height of the p-th layer of windings in the primary winding, b represents the total height of the primary winding, and Nl represents the number of turns of the wire in each layer of the winding.

[0045] The present invention also provides a design device for a high-frequency transformer with a round wire type winding based on direct current resistance, including:

[0046] A parameter acquisition module, configured to acquire the number of layers, total height, total thickness, porosity, number of turns of the wire in each layer of the winding, average length of each turn of the winding, resistivity, conductivity, permeability of the round wire, and the current value of the input direct current.

[0047] A direct current resistance calculation module, configured to calculate the resistance value of the direct current generated by the current primary winding based on the parameters acquired by the parameter acquisition module by using a direct current resistance calculation model.

[0048] A parameter adjustment module, configured to adjust the specification parameters of the primary winding according to the direct current resistance value, change the direct current resistance, and obtain a high-frequency transformer that meets the circuit requirements.

[0049] The above technical solution of the present invention has the following advantages compared with the prior art:

[0050] For the design method of the high-frequency transformer with a round wire type winding based on direct current resistance of the present invention, the direct current resistance of the primary winding is obtained by using a direct current resistance calculation model, and the specification parameters of the current primary winding are adjusted according to the direct current resistance value to design a transformer that better meets the circuit requirements. The acquisition of the direct current resistance calculation model is to equivalently transform the round wire type winding into a rectangular wire winding with the same cross-sectional area, use the Poynting vector to calculate the instantaneous power, and through strict logical derivation, finally, the direct current resistance value can be calculated according to the quotient of the product of the average length of a single turn of the winding, the total number of winding layers, and the square of the number of turns of the wire in each layer of the winding and the product of the conductivity of the copper winding, the total height of the winding, and the width of the p-th layer of the rectangular wire winding. The required parameters do not include porosity. Therefore, the measurement result is not affected by the size of the porosity, making the calculation result of the direct current resistance more accurate; the staff accurately adjusts the specification parameters of the primary winding according to the accurate direct current resistance value to accurately design a transformer that meets the circuit requirements. Description of the Drawings

[0051] In order to make the content of the present invention easier to be clearly understood, the following further details the present invention according to specific embodiments of the present invention in conjunction with the drawings, where:

[0052] Figure 1 is the implementation flowchart of the direct current resistance calculation model provided by the present invention;

[0053] Figure 2 is the structural diagram of the high-frequency transformer with a round wire type winding on the ZX plane;

[0054] Figure 3 It is a schematic diagram of equivalent circular wire winding into rectangular wire winding with the same cross-sectional area;

[0055] Figure 4 It is a schematic diagram of boundary conditions;

[0056] Figure 5 It is a schematic diagram of integration path;

[0057] Figure 6 This is the structural block diagram of a design device for high-frequency transformers with circular wire windings based on DC resistance provided by the embodiments of the present invention. Detailed implementation manners

[0058] The core of the present invention is to provide a design method and device for high-frequency transformers with circular wire windings based on DC resistance, so that the calculation result of DC resistance is more accurate, and the specification parameters of the primary winding can be better adjusted to make the transformer meet the circuit requirements.

[0059] In order to enable those skilled in the art to better understand the solution of the present invention, the present invention will be further described in detail below with reference to the drawings and specific implementation manners. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0060] The specific operation steps of a design method for high-frequency transformers with circular wire windings based on DC resistance provided by the present invention are as follows:

[0061] Obtain the specification parameters of the primary winding of the circular wire transformer and the current value of the input DC current, input them into the DC resistance calculation model, and obtain the DC resistance value generated by the primary winding;

[0062] According to the current DC resistance value, adjust the specification parameters of the primary winding to obtain a high-frequency transformer that meets the circuit requirements.

[0063] Please refer to Figure 1 , Figure 1 This is the implementation process diagram of the DC resistance calculation model in a design method for high-frequency transformers with circular wire windings based on DC resistance provided by the present invention, including:

[0064] S1: Equivalent the circular wire winding to be measured into a rectangular wire winding with the same cross-sectional area and pass a DC current through it;

[0065] Refer to Figure 2Structural diagram of a high-frequency transformer with a round wire winding in the ZX plane. The magnetic core used is an EE core. The three inner-layer coils represent the primary winding of the round wire winding, and the two outer-layer coils represent the secondary winding. The dots in the winding represent the direction of the current flowing in, and the crosses in the winding represent the direction of the current flowing out.

[0066] For the convenience of analysis, we equivalent the round wire winding to a rectangular wire winding with the same cross-sectional area. In this way, there are gaps between the rectangular windings, as Figure 3 shown. c is the height of a single-turn rectangular winding, b is the total height of the round winding, u is the insulation layer thickness, d is the diameter of a single-turn round wire winding, and h is the width of the rectangular winding. lT is the average length of a single-turn winding. Therefore, for the equivalent rectangular wire winding, its porosity is:

[0067] S2: Based on the current density in the wire of the round wire winding, according to Ampere's circuital law, the magnetic field strength in the p-th layer of the winding is obtained;

[0068] When a direct current is passed through the round wire winding, the current on the cross-sectional area of the wire is uniformly distributed. At this time, the current density J in the wire can be calculated by dividing the total current NlI by the total cross-sectional area ηbh. According to Ampere's circuital law, we can deduce the magnetic field strength in the p-th layer of the winding. According to the Figure 4 boundary conditions shown, the magnetic field strength in the p-th layer of the winding we deduced is where η represents the porosity, x = 0 / h, h represents the width of the p-th layer of the rectangular winding, as Figure 4 shown. H0 represents the magnetic field strength on the outer surface of the first-layer primary winding, Nl represents the number of turns of the wire in each layer of the winding, I represents the magnitude of the current, b represents the total height of the winding. This formula represents the variation of the magnetic field strength in the p-th layer of the winding with the thickness of the winding, that is, the variation of the magnetic field strength with the x-axis.

[0069] S3: Based on the expression of the magnetic field strength in the p-th layer of the winding, according to the relationship between the electric field and the current density, the electric field strength in the p-th layer of the winding is obtained:

[0070]

[0071] S4: According to the product of the magnetic field strength and the electric field strength on the outer surface or the inner surface of the p-th layer of the winding, the power flow density (E y H z ) x＝h / 0 ;

[0072] The Poynting vector in the p-th layer of the winding of the primary coil is It shows that the direction of the Poynting vector is the negative direction of the x-axis. Therefore, the instantaneous power flows into the outer boundary of the p-th layer conductor and flows out of the inner boundary of the p-th layer conductor. Figure 4 The inner and outer boundaries of the p-th layer winding are marked. The boundary of the p-th layer winding adjacent to the magnetic core is called the inner boundary (inner surface), and its magnetic field strength is The boundary of the p-th layer winding far from the magnetic core is called the outer boundary (outer surface), and its magnetic field strength is

[0073] S5: Obtain the differential area of the outer surface or inner surface of the p-th layer winding according to the product of the line integral in the vertical direction of the winding, the average length of a single-turn winding, and the porosity.

[0074] The differential areas of the inner and outer boundaries of the p-th layer winding can be respectively expressed as the line integral along the z-axis multiplied by the average length of a single-turn winding multiplied by the porosity. In this way, the differential areas in the previous two integral expressions are transformed into line integrals along the z-axis, and the calculation method is simple:

[0075]

[0076] S6: Calculate the integral area of the Poynting vector on the outer surface or inner surface of the p-th layer winding according to the power flow density and the differential area on the outer surface or inner surface of the p-th layer winding, and obtain the instantaneous power flowing into the outer surface of the p-th layer winding or flowing out of the inner surface of the p-th layer winding.

[0077] The instantaneous power flowing into the outer boundary of the p-th layer winding can be obtained by calculating the surface integral of the Poynting vector. At this time, the Poynting vector is the value of the Poynting vector at x = h, that is, the outer surface of the winding, and the integral area at this time is the area of the outer surface of the winding at x = h

[0078] The instantaneous power flowing out of the inner boundary of the p-th layer winding can also be obtained by calculating the surface integral of the Poynting vector. At this time, the Poynting vector is the value of the Poynting vector at x = 0, that is, the inner surface of the winding, and the integral area at this time is the area of the inner surface of the winding at x = 0

[0079] S7: Obtain the instantaneous power consumed inside the p-th layer winding according to the difference between the integral area of the Poynting vector on the outer surface of the p-th layer winding and the integral area of the Poynting vector on the inner surface of the p-th layer winding:

[0080]

[0081] Among them, η is the porosity, b is the total height of the winding, and lT is the average length of a single-turn winding.

[0082] S8: Sum the instantaneous power consumed inside the m layers of windings in the primary winding to calculate the total instantaneous power consumed by the primary winding, which is the quotient of the product of the average length of a single-turn winding, the total number of winding layers, and the square of the total current passing through the pth layer of winding and the product of the conductivity of the copper winding, the total height of the winding, and the width of the rectangular wire winding in the pth layer:

[0083]

[0084] S9: Obtain the magnitude of the DC resistance according to the quotient of the total instantaneous power and the square of the current, which is the quotient of the product of the average length of a single-turn winding, the total number of winding layers, and the square of the number of turns of the wire in each layer of winding and the product of the conductivity of the copper winding, the total height of the winding, and the width of the rectangular wire winding in the pth layer:

[0085] According to the active power formula P = I 2 Rdc, the DC resistance calculation model of the primary winding can be obtained:

[0086] The DC resistance calculation model can also be expressed in terms of the porosity. Substitute the porosity into the above formula and rearrange the above formula to obtain another form of the DC resistance calculation model containing the porosity:

[0087]

[0088] It can be seen that the DC resistance of the round wire type winding transformer cannot be simply calculated according to but needs to be multiplied by the porosity.

[0089] The method for obtaining the DC resistance calculation model described in the present invention equates the round wire type winding to a rectangular wire winding with the same cross-sectional area, uses the Poynting vector to calculate the instantaneous power, and through rigorous logical derivation, finally the magnitude of the DC resistance can be calculated according to the quotient of the product of the average length of a single-turn winding, the total number of winding layers, and the square of the number of turns of the wire in each layer of winding and the product of the conductivity of the copper winding, the total height of the winding, and the width of the rectangular wire winding in the pth layer. The required parameters do not include the porosity. Therefore, the measurement result is not affected by the size of the porosity. Whether the porosity is large or small, and whether the turns are sparse or dense, the calculation result is very accurate, thus making the calculation result of the DC resistance more precise, and enabling better adjustment of the primary winding specification parameters to make the transformer meet the circuit requirements.

[0090] Based on the above embodiments, step S3 is further described:

[0091] As Figure 5 shown, taking the vertex at the lower left corner of the cross-section of the pth layer of winding as the origin, and the perimeter along the counterclockwise direction of the cross-section as the integration path The line integral of the magnetic field intensity H(x) along the perimeter of the cross-section of the p-th layer winding calculated according to Maxwell's equations is the conduction current passing through the total cross-sectional area s of the rectangular wires in the p-th layer winding c of the conduction current J represents the current density. Since there is no displacement current in the case of direct current, the influence of displacement current is not included in the formula. This formula converts the line integral of the magnetic field intensity into the surface integral of the current density. Such a conversion facilitates the subsequent solution.

[0092] According to Stokes' theorem, the line integral of the magnetic field intensity of the p-th layer winding along the perimeter of the cross-section of the p-th layer winding is also equal to the surface integral of the curl of the magnetic field on the cross-sectional area s of the p-th layer winding The calculated curl of the magnetic field is the product of the porosity and the conduction current density

[0093] Since the conduction current density is the product of the conductivity σ and the electric field intensity of the product The calculated curl of the magnetic field is the product of the porosity, conductivity and electric field intensity

[0094] Since the curl of the magnetic field intensity can be expressed as The calculated electric field intensity in the p-th layer winding

[0095] The embodiment of the present invention also provides a device for a design method of a circular wire type winding high-frequency transformer based on direct current resistance. The specific device includes:

[0096] A parameter acquisition module, configured to acquire the number of layers, total height, total thickness, porosity, number of turns of the wire in each layer of the winding, average length of each turn of the winding, resistivity, conductivity, permeability of the circular wire, and the current value of the input direct current;

[0097] A direct current resistance calculation module, configured to calculate the direct current resistance value generated by the current primary winding based on the parameters acquired by the parameter acquisition module by using a direct current resistance calculation model;

[0098] A parameter adjustment module, configured to adjust the specification parameters of the primary winding according to the direct current resistance value, change the direct current resistance, and obtain a high-frequency transformer that meets the circuit requirements.

[0099] Specifically, please refer to Figure 6 , Figure 6 which is a structural block diagram of a direct current resistance calculation model provided by the embodiment of the present invention, including:

[0100] The simulated energization module 100 is used to equivalently transform the to-be-tested round wire type winding into a rectangular wire winding with the same cross-sectional area and apply a direct current thereto;

[0101] The magnetic field intensity calculation module 200 is used to calculate the quotient of the total current passing through the p-th layer winding and the total cross-sectional area of the rectangular wire, the product of the porosity and the width of the p-th layer rectangular wire winding or 0, and add it to the product of the magnetic field intensity on the outer surface of the first layer primary winding and p - 1 to obtain the magnetic field intensity at the outer surface or the inner surface of the p-th layer winding. The total cross-sectional area of the rectangular wire is the product of the porosity, the width of the p-th layer rectangular wire winding, and the total height of the winding;

[0102] The electric field intensity calculation module 300 is used to obtain the electric field intensity in the p-th layer winding according to the quotient of the total current passing through the p-th layer winding and the product of the total cross-sectional area of the rectangular wire and the conductivity of the copper winding;

[0103] The power flow density calculation module 400 is used to obtain the power flow density at the outer surface or the inner surface of the p-th layer winding according to the product of the magnetic field intensity and the electric field intensity at the outer surface or the inner surface of the p-th layer winding;

[0104] The side surface micro-element area calculation module 500 is used to obtain the micro-element area at the outer surface or the inner surface of the p-th layer winding according to the product of the line integral in the vertical direction of the winding, the average length of a single-turn winding, and the porosity;

[0105] The instantaneous power of inflow and outflow calculation module 600 is used to calculate the integral area of the Poynting vector at the outer surface or the inner surface of the p-th layer winding according to the power flow density and the micro-element area at the outer surface or the inner surface of the p-th layer winding, and obtain the instantaneous power flowing into the outer surface of the p-th layer winding or flowing out of the inner surface of the p-th layer winding, which is the product of the porosity, the power flow density at the outer surface or the inner surface of the p-th layer winding, the total height of the winding, and the average length of a single-turn winding;

[0106] The power consumption calculation module 700 is used to obtain the instantaneous power consumed inside the p-th layer winding according to the difference between the integral area of the Poynting vector on the outer surface of the p-th layer winding and the integral area of the Poynting vector on the inner surface of the p-th layer winding;

[0107] The total instantaneous power calculation module 800 is used to calculate the total instantaneous power consumed by the primary winding, which is the quotient of the product of the average length of a single-turn winding, the total number of winding layers, and the square of the total current passing through the p-th layer winding and the product of the conductivity of the copper winding, the total height of the winding, and the width of the p-th layer rectangular wire winding;

[0108] The DC resistance calculation module 900 is used to obtain the magnitude of the DC resistance according to the quotient of the total instantaneous power and the square of the current, which is the quotient of the product of the average length of a single-turn winding, the total number of winding layers, and the square of the number of turns of the wire in each winding layer and the product of the copper winding conductivity, the total height of the winding, and the width of the rectangular wire winding in the p-th layer.

[0109] The circular wire type winding DC resistance measuring device of this embodiment is used to implement the aforementioned circular wire type winding DC resistance measuring method. Therefore, the specific implementation manners in the circular wire type winding DC resistance measuring device can be seen in the embodiment part of the circular wire type winding DC resistance measuring method above. For example, the simulation power-on module 100, the magnetic field strength calculation module 200, the electric field strength calculation module 300, the power flow density calculation module 400, the side surface micro-element area calculation module 500, the inflow and outflow instantaneous power calculation module 600, the power consumption calculation module 700, the total instantaneous power calculation module 800, and the DC resistance calculation module 900 are respectively used to implement steps S1, S2, S3, S4, S5, S6, S7, S8, S9 in the above circular wire type winding DC resistance measuring method. Therefore, the specific implementation manners can refer to the descriptions of the corresponding various part embodiments and will not be elaborated here.

[0110] A specific embodiment of the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned circular wire type winding DC resistance measuring method are implemented.

[0111] The circular wire type winding high-frequency transformer design method based on DC resistance of the present invention uses a DC resistance calculation model to obtain the DC resistance of the primary winding, and adjusts the specification parameters of the current primary winding according to the DC resistance value to design a transformer that better meets the circuit requirements. The acquisition of the DC resistance calculation model is to equivalent the circular wire type winding to a rectangular wire winding with the same cross-sectional area, use the Poynting vector to calculate the instantaneous power, and through strict logical derivation, finally the magnitude of the DC resistance can be calculated according to the quotient of the product of the average length of a single-turn winding, the total number of winding layers, and the square of the number of turns of the wire in each winding layer and the product of the copper winding conductivity, the total height of the winding, and the width of the rectangular wire winding in the p-th layer. The required parameters do not include the porosity. Therefore, the measurement result is not affected by the size of the porosity, making the calculation result of the DC resistance more accurate; the staff can accurately adjust the specification parameters of the primary winding according to the accurate DC resistance value and precisely design a transformer that meets the circuit requirements.

[0112] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memory, CD-ROM, optical memory, etc.) that contain computer-usable program code.

[0113] The present application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram can be implemented by computer program instructions, and the combination of the flows and / or blocks in the flowchart and / or block diagram can also be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0114] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including instruction means, and the instruction means implement the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0115] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0116] Obviously, the above embodiments are only examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A design method for a high-frequency transformer with a round wire winding based on DC resistance, characterized in that, Including: Obtain the specification parameters of the primary winding of the round wire type transformer and the current value of the input DC current. In the input DC resistance calculation model, obtain the DC resistance value generated by the primary winding. According to the current DC resistance value, adjust the specification parameters of the primary winding to obtain a high-frequency transformer that meets the circuit requirements. The obtaining process of the DC resistance calculation model includes: Equivalent the round wire type winding to be measured to a rectangular wire winding with the same cross-sectional area and pass a DC current through it. Based on the current density in the wire of the round wire type winding, according to Ampere's circuital law, obtain the magnetic field strength in the p-th layer of the winding. Based on the magnetic field strength expression in the p-th layer of the winding, according to the relationship between the electric field and the current density, obtain the electric field strength in the p-th layer of the winding. According to the product of the magnetic field strength and the electric field strength on the outer surface or the inner surface of the p-th layer of the winding, obtain the power flow density on the outer surface or the inner surface of the p-th layer of the winding. According to the product of the line integral in the vertical direction of the winding, the average length of a single-turn winding, and the porosity, obtain the differential area on the outer surface or the inner surface of the p-th layer of the winding. Calculate the integral area of the Poynting vector on the outer surface or the inner surface of the p-th layer of the winding according to the power flow density and the differential area on the outer surface or the inner surface of the p-th layer of the winding, and obtain the instantaneous power flowing into the outer surface of the p-th layer of the winding or flowing out of the inner surface of the p-th layer of the winding. According to the difference between the integral area of the Poynting vector on the outer surface of the p-th layer of the winding and the integral area of the Poynting vector on the inner surface of the p-th layer of the winding, obtain the instantaneous power consumed inside the p-th layer of the winding. Sum up the instantaneous power consumed inside the m layers of the winding in the primary winding to obtain the total instantaneous power equation consumed by the primary winding. According to the total instantaneous power equation and the active power expression, obtain the DC resistance calculation model. Among them, l T is the average length of a single-turn winding, m represents the total number of layers of the primary winding, N l represents the number of turns of the wire in each layer of the winding, σ represents the conductivity of the primary winding, b represents the total height of the primary winding, and h represents the width of the rectangular wire winding of the p-th layer.

2. The design method for a high-frequency transformer with a round wire winding based on DC resistance according to claim 1, characterized in that, The obtaining of the magnetic field strength in the p-th layer of the winding based on the current density in the wire of the round wire type winding according to Ampere's circuital law is expressed by the formula: Among them, η represents the porosity, J represents the current density, x ∈ [0, h], h represents the width of the rectangular wire winding of the p-th layer, H0 represents the magnetic field strength on the outer surface of the first-layer primary winding, N l represents the number of turns of the wire in each layer of the winding, I represents the magnitude of the direct current, and b represents the total height of the primary winding.

3. The design method for a high-frequency transformer with a round wire winding based on DC resistance according to claim 2, characterized in that, The obtaining of the electric field strength in the p-th layer of the winding based on the magnetic field strength expression in the p-th layer of the winding according to the relationship between the electric field and the current density includes: Taking the vertex at the lower left corner of the cross-section of the p-th layer winding as the origin, and the perimeter in the counterclockwise direction along the cross-section as the integration path According to Maxwell's equations, the line integral of the magnetic field strength H(x) of the p-th layer winding along the perimeter of the cross-section of the p-th layer winding is the conduction current passing through the total cross-sectional area s of the rectangular wires in the p-th layer winding c J represents the current density;​ According to Stokes' theorem, the line integral of the magnetic field intensity of the p-th layer winding along the perimeter of the cross-section of the p-th layer winding is also equal to the curl of the magnetic field over the surface area s of the cross-section of the p-th layer winding The calculated curl of the magnetic field is the product of the porosity and the conduction current density Since the conduction current density is the product of the conductivity σ and the electric field strength the curl of the magnetic field is calculated to be the product of the porosity, conductivity, and electric field strength ​ Since the curl of the magnetic field strength can be expressed as The electric field strength in the p-th layer winding is calculated 4. The design method for a high-frequency transformer with a round wire winding based on DC resistance according to claim 1, characterized in that, The line integral according to the vertical direction of the winding The average length l of a single-turn winding T The product of the porosity η to obtain the differential area of the outer or inner surface of the p-th layer winding, which is expressed by the formula: The differential area of the inner surface of the p-th layer winding The differential area of the outer surface of the p-layer winding where a x is a unit vector in the horizontal direction.

5. The design method for a high-frequency transformer with a round wire winding based on DC resistance according to claim 4, characterized in that, The product of the magnetic field strength E at the outer or inner surface of the p-th layer winding y and the electric field strength H z is used to obtain the power flow density (E y H z ) x＝h / 0 .

6. The design method for a high-frequency transformer with a round wire winding based on DC resistance according to claim 5, characterized in that, Obtaining the instantaneous power \(P\) consumed inside the \(p\)-th layer winding based on the difference between the integrated area of the Poynting vector on the outer surface of the \(p\)-th layer winding and the integrated area of the Poynting vector on the inner surface of the \(p\)-th layer winding p , which is expressed by the formula as follows: Among them, is the Poynting vector on the outer or inner surface of the p-th layer winding, (E y H z ) x＝h / 0 is the power flow density at the outer or inner surface of the p-th layer winding, η is the porosity, b is the total height of the primary winding, l T is the average length of a single-turn winding.

7. The design method of a high-frequency transformer with a round wire type winding based on direct current resistance according to claim 6, wherein, The summing up of the instantaneous power consumed inside the m layers of the winding in the primary winding to obtain the total instantaneous power equation consumed by the primary winding is expressed as: where l T is the average length of a single-turn winding, m represents the total number of layers of the primary winding, N l represents the number of turns of the wire in each layer of the winding, I represents the magnitude of the direct current, σ represents the conductivity of the primary winding, b represents the total height of the primary winding, and h represents the width of the rectangular wire winding in the p-th layer.

8. The design method of a high-frequency transformer with a round wire type winding based on direct current resistance according to claim 7, wherein, The obtaining of the DC resistance calculation model according to the total instantaneous power equation and the active power expression is expressed by the formula:

9. The design method of a high-frequency transformer with a round wire type winding based on direct current resistance according to claim 8, wherein, Substitute the porosity into the DC resistance calculation model to obtain another expression of the DC resistance calculation model, which is: Among them, the porosity c represents the height of the p-th layer winding in the primary winding, b represents the total height of the primary winding, and N l represents the number of turns of the wire in each layer of the winding.

10. An apparatus applying the design method of a high-frequency transformer with a round wire type winding based on direct current resistance according to any one of claims 1 to 9, wherein, Including: A parameter acquisition module for acquiring the number of layers, total height, total thickness, porosity, number of turns of the wire in each layer of the winding, average length of each turn of the winding, resistivity, conductivity, magnetic permeability of the round wire, and the current value of the input DC current of the round wire type primary winding. A DC resistance calculation module for calculating the DC resistance value generated by the current primary winding based on the parameters acquired by the parameter acquisition module using the DC resistance calculation model. A parameter adjustment module for adjusting the specification parameters of the primary winding according to the DC resistance value, changing the DC resistance, and obtaining a high-frequency transformer that meets the circuit requirements.

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