Transformer winding loss calculation method and related device

Abstract

The invention discloses a transformer winding loss calculation method and a related device. The method comprises the steps of obtaining harmonic current of an environment where a transformer winding is located; calculating the AC resistance of the transformer winding according to the harmonic current through a skin effect and a proximity effect; acquiring a non-sine-wave current of an environment where the transformer winding is located, and decomposing the non-sine-wave current into a plurality of harmonic components; after the height of the transformer winding is adjusted to be equal to the height of the magnetic core window based on a preset transformer winding design method, the frequency of each harmonic component is calculated, and the total winding loss is calculated according to the frequency of the harmonic component and the alternating-current resistance. By optimizing the structure of the winding and the loss calculation method, the operation efficiency and reliability of the medium-frequency transformer are effectively improved, and energy loss caused by the high-frequency electromagnetic effect is reduced. Therefore, the problems of loss increase caused by inaccurate winding loss calculation and winding height mismatching in a high-frequency environment and complex loss caused by harmonic current in the prior art are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics and electrical engineering, and in particular to a method for calculating winding loss of a transformer and a related device. Background Art

[0002] Unlike traditional industrial frequency transformers, medium-frequency transformers typically operate at frequencies between 400Hz and 2000Hz, making them remarkably compact and lightweight, making them suitable for space-constrained and mobile applications. With the widespread adoption of new energy sources, particularly wind power, photovoltaics, and distributed energy storage systems, medium-frequency transformers, as a core component of power distribution systems, play an irreplaceable role in achieving efficient energy transmission and storage management, flexibly adjusting power quality, and improving power supply stability.

[0003] Despite the broad application prospects of medium-frequency transformers, the following major issues remain in the calculation and design of winding losses in high-frequency environments. Regarding winding loss calculation, when used in power electronic equipment, medium-frequency transformers are often affected by non-sinusoidal currents. Harmonic currents complicate winding losses, especially when high-frequency harmonic content is high. Existing technologies struggle to accurately analyze the impact of each order of harmonics on losses. Regarding winding design, in large-capacity medium-frequency transformers, the height of the copper foil winding often differs from the height of the core window. This mismatch alters the electromagnetic properties of the winding, further increasing the complexity of loss calculation. Traditional designs cannot effectively address this winding height mismatch, thereby reducing transformer design efficiency. Furthermore, existing winding design methods are relatively simplistic and cannot dynamically adjust based on real-time electromagnetic field distribution. The presence of parasitic inductance and eddy current losses between windings reduces overall system efficiency and can lead to transformer overheating and shortened service life. Summary of the Invention

[0004] The present invention provides a transformer winding loss calculation method and related devices, which are used to solve the problems of inaccurate winding loss calculation in high-frequency environments, increased losses caused by winding height mismatch, and complex losses caused by harmonic currents in the prior art.

[0005] In view of this, a first aspect of the present invention provides a method for calculating winding loss of a transformer, the method comprising:

[0006] Obtain the harmonic current of the environment where the transformer winding is located;

[0007] Calculating the AC resistance of the transformer winding based on the harmonic current through skin effect and proximity effect;

[0008] Obtaining a non-sinusoidal current in an environment where a transformer winding is located, and decomposing the non-sinusoidal current into a plurality of harmonic components;

[0009] After adjusting the height of the transformer winding to be equal to the height of the core window based on a preset transformer winding design method, the frequency of each harmonic component is calculated respectively, and the total winding loss is calculated based on the frequency of the harmonic component and the AC resistance.

[0010] Optionally, calculating the AC resistance of the transformer winding according to the harmonic current through the skin effect and the proximity effect includes:

[0011] Based on Fourier decomposition theory, the harmonic current is decomposed into several frequency components, and the skin effect and proximity effect are analyzed and calculated for each of the frequency components to obtain the AC resistance of the winding;

[0012] Wherein, the calculation expression of the AC resistance is:

[0013] ;

[0014] Where, is the AC resistance, is the DC resistance, is the AC-DC resistance ratio correction coefficient, is the frequency-dependent eddy current factor, is the operating frequency.

[0015] Optionally, respectively calculating the frequency of each harmonic component includes:

[0016] Based on Fourier decomposition theory, the non-sinusoidal current is decomposed into several harmonic components;

[0017] Calculate the frequency of each harmonic component based on a frequency calculation formula;

[0018] Wherein, the frequency calculation formula is:

[0019] ;

[0020] Where, is the frequency of the harmonic component, is the operating frequency, is the harmonic order.

[0021] Optionally, the calculating the total winding loss according to the frequency of the harmonic component and the AC resistance includes:

[0022] Calculating harmonic component loss based on the frequency of the harmonic component and the AC resistance based on a loss calculation formula;

[0023] Adding the losses of the harmonic components to obtain the total winding loss;

[0024] The loss calculation formula is:

[0025] ;

[0026] Where, is the harmonic component loss, For the The current amplitude of the order harmonic, is the AC resistance at the frequency corresponding to the harmonic component.

[0027] Optionally, the preset transformer winding design method is based on which the height of the transformer winding is adjusted to be equal to the height of the magnetic core window, including:

[0028] determining a type of an initial winding for designing a winding, the type of the initial winding comprising: a segmented conductor;

[0029] Through the gap factor folding the initial winding into a copper foil winding having the same geometric height as the initial winding;

[0030] Through the gap factor The copper foil winding is folded into a copper foil winding having a height equal to that of the magnetic core window.

[0031] Optionally, the gap factor The expression is:

[0032] ;

[0033] Where, is the number of segments of a layer of winding, is the height of a single-layer winding, is the total height of one layer of winding.

[0034] Optionally, the gap factor The expression is:

[0035] ;

[0036] Where, is the total height of one layer of winding, is the core window height.

[0037] Optionally, it further includes: through the gap factor and the gap factor The conductivity of the winding is modified. The expression of the modified conductivity of the winding is:

[0038] ;

[0039] Where, is the conductivity of the winding after the winding modification, and is the gap factor, is the penetration ratio of the winding after converting the total gap factor, is the conductivity of the winding before winding modification.

[0040] A second aspect of the present invention provides a device for calculating winding loss of a transformer, the device comprising a processor and a memory:

[0041] The memory is used to store program code and transmit the program code to the processor;

[0042] The processor is configured to execute the steps of the transformer winding loss calculation method as described in the first aspect according to the instructions in the program code.

[0043] A third aspect of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium is used to store program code, and the program code is used to execute the transformer winding loss calculation method described in the first aspect.

[0044] It can be seen from the above technical solutions that the present invention has the following advantages:

[0045] The present invention provides a transformer winding loss calculation method that, by optimizing the winding structure and loss calculation method, can effectively improve the operating efficiency and reliability of medium-frequency transformers and reduce energy losses caused by high-frequency electromagnetic effects. Experimental results show that the present invention can significantly reduce total winding losses, improve the heat dissipation of the equipment, and extend the service life of the transformer. This solves the problems of existing technologies such as inaccurate winding loss calculation in high-frequency environments, increased losses due to winding height mismatch, and complex losses caused by harmonic currents. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0047] Figure 1 A schematic diagram of a flow chart of a method for calculating transformer winding loss provided by an embodiment of the present invention;

[0048] Figure 2 A schematic flow chart of a transformer winding design method provided in an embodiment of the present invention;

[0049] Figure 3A schematic diagram of adjusting the porosity factor provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0050] In order to make the purpose, features, and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0051] See also Figure 1 , a method for calculating transformer winding loss provided in an embodiment of the present invention includes:

[0052] Step 101: Obtain harmonic currents of the environment in which the transformer winding is located.

[0053] It should be noted that the harmonic currents in the environment in which the transformer windings are located can be monitored in real time using a current transformer or other current measuring device. In practical applications, the presence of various nonlinear loads in the power grid can cause distortion of the current waveform, generating harmonic currents. These harmonic currents can affect the losses of the transformer windings. Therefore, accurately obtaining the harmonic currents in the environment in which the transformer windings are located is an important prerequisite for accurately calculating the winding losses. In order to further improve the accuracy of the winding loss calculation, the embodiments of the present invention can also filter the obtained harmonic currents to remove noise interference and obtain more accurate harmonic current data.

[0054] Step 102: Calculate the AC resistance of the transformer winding based on the harmonic current through the skin effect and the proximity effect.

[0055] In one embodiment, step 102 includes:

[0056] Based on Fourier decomposition theory, the harmonic current is decomposed into several frequency components, and the skin effect and proximity effect are analyzed and calculated for each frequency component to obtain the AC resistance of the winding;

[0057] Among them, the calculation expression of AC resistance is:

[0058] ;

[0059] Where, is the AC resistance, is the DC resistance, is the AC-DC resistance ratio correction coefficient, is the frequency-dependent eddy current factor, By adjusting the coefficients S and G, it is possible to adapt to the resistance changes of different types of windings.

[0060] It should be noted that, based on Fourier decomposition theory, the harmonic current is decomposed into multiple frequency components, and the skin effect and proximity effect are analyzed and calculated for each frequency component. This method can more accurately calculate the AC resistance of the winding, avoiding the error accumulation caused by ignoring high-frequency harmonics in traditional calculation methods. The skin effect, also known as the skin effect, refers to the phenomenon that when an alternating current passes through a conductor, the current density is unevenly distributed across the conductor's cross-section and decreases with increasing distance from the conductor's surface, with most of the current concentrated near the conductor's surface. This effect is caused by the alternating magnetic field generated by the alternating current, which induces an electromotive force within the conductor. According to Lenz's law, this induced electromotive force hinders the flow of current. In the center of the conductor, the induced electromotive force generated by the alternating magnetic field has a stronger effect on the current, causing the current to flow more toward the conductor's surface. The proximity effect mainly refers to the phenomenon that in an alternating magnetic field, the current distribution within a conductor changes due to the influence of the magnetic field generated by the current in the adjacent conductor. When two or more conductors are close to each other, they generate mutual electromagnetic interaction. For example, in high-frequency circuits, the alternating magnetic field generated by alternating current between adjacent conductors can cause the current distribution in the conductors to become uneven. The previously evenly distributed current tends to concentrate on the side of the conductor closest to the adjacent conductor. This effect increases the equivalent resistance of the conductors and changes their inductance, impacting circuit performance by increasing power loss and reducing signal transmission quality.

[0061] Step 103: Obtain the non-sinusoidal current in the environment where the transformer winding is located, and decompose the non-sinusoidal current into several harmonic components.

[0062] In one embodiment, in step 103, the non-sinusoidal current is decomposed into several harmonic components, including:

[0063] Based on Fourier decomposition theory, the non-sinusoidal current is decomposed into several harmonic components;

[0064] It should be noted that based on the Fourier decomposition principle, the non-sinusoidal current is decomposed into multiple harmonic components, and the frequency of each harmonic component is Among them, the Fourier decomposition principle: also known as the basic principle of Fourier series and Fourier transform, was proposed by French mathematician Fourier. This principle states that any periodic function or signal can be expressed as a weighted sum of a series of sine waves and cosine waves (or complex exponential functions) of different frequencies, and non-periodic functions can be expressed by continuous frequency components.

[0065] Step 104 : After adjusting the height of the transformer winding to be equal to the height of the core window based on a preset transformer winding design method, the frequency of each harmonic component is calculated respectively, and the total winding loss is calculated based on the frequency of the harmonic component and the AC resistance.

[0066] like Figure 2 As shown, in one embodiment, in step 104, adjusting the height of the transformer winding to be equal to the height of the magnetic core window based on a preset transformer winding design method includes:

[0067] Step 201: Determine the type of an initial winding used for designing a winding. The type of the initial winding includes: a segmented conductor.

[0068] It should be noted that in order to solve the problem of mismatch between the winding height and the core window height, an adjustment method based on the aperture factor is proposed. The winding height is adjusted to an equivalent structure that is consistent with the core window height. Specifically: In fact, the copper foil winding height is often not equal to the core window height. In order to make the winding height equal to the core window height, the aperture factor algorithm is used to perform equivalent conversion on the winding. The present invention preferably uses a segmented conductor, such as Figure 3 As shown, the leftmost winding is a segmented type of conductor.

[0069] Step 202: Through the gap factor Folding the initial winding into a copper foil winding having the same geometric height as the initial winding;

[0070] Step 203: Through the gap factor Fold the copper foil winding into a copper foil winding with the same height as the core window.

[0071] It should be noted that the gap factor Fold the winding into a copper foil winding with the same geometric height, see Figure 3 The middle winding, through the gap factor Fold the winding into a copper foil winding with the same height as the core window, where:

[0072]

[0073]

[0074] Where, is the number of segments of a layer of winding, d h is the height of a single-layer winding, h w is the total height of one layer of winding, h c is the core window height. After two equivalent winding cross-sectional areas, the actual area will change. Furthermore, in order to ensure that the DC resistance is equal, the gap factor is used. and the gap factor The conductivity of the winding is modified. The expression of the modified conductivity of the winding is:

[0075] ;

[0076] Where, is the conductivity of the winding after the winding modification, and is the gap factor, is the penetration ratio of the winding after converting the total gap factor, is the conductivity of the winding before winding modification.

[0077] .

[0078] Where Δ' is the penetration ratio of the winding after the total gap factor is converted, and Δ is the penetration ratio before conversion.

[0079] This embodiment provides a transformer winding design method that uses a void factor algorithm to adjust the mismatched winding height to an equivalent height consistent with the core window height, thereby improving the accuracy of winding loss calculation.

[0080] In one embodiment, in step 104, the frequency of each harmonic component is calculated respectively, and the total winding loss is calculated based on the frequency of the harmonic component and the AC resistance, including:

[0081] Based on Fourier decomposition theory, the non-sinusoidal current is decomposed into several harmonic components, and the frequency of each harmonic component is calculated based on the frequency calculation formula.

[0082] The frequency calculation formula is:

[0083] ;

[0084] Where, is the frequency of the harmonic component, is the operating frequency, is the harmonic order.

[0085] Based on the loss calculation formula, the harmonic component loss is calculated according to the frequency of the harmonic component and the AC resistance; the total winding loss is obtained by adding up the losses of each harmonic component.

[0086] The loss calculation formula is:

[0087] ;

[0088] Where, is the harmonic component loss, For the The current amplitude of the order harmonic, is the AC resistance at the frequency corresponding to the harmonic component.

[0089] It can be understood that the loss of each harmonic component The above loss calculation formula can be used to calculate the total winding loss by summing the losses of each harmonic component. This method is not only accurate but also comprehensively considers the impact of each harmonic component in the current on the winding loss. In practical applications, by precisely measuring the current amplitude of each harmonic component and the corresponding AC resistance, the loss generated by each harmonic component can be accurately calculated. Subsequently, these loss values ​​are accumulated to obtain the total loss of the entire transformer winding. Application of this method helps to more accurately evaluate the energy efficiency and lifespan of the transformer.

[0090] The present invention provides a transformer winding loss calculation method that, by optimizing the winding structure and loss calculation method, can effectively improve the operating efficiency and reliability of medium-frequency transformers and reduce energy losses caused by high-frequency electromagnetic effects. Experimental results show that the present invention can significantly reduce total winding losses, improve the heat dissipation of the equipment, and extend the service life of the transformer. This solves the problems of existing technologies such as inaccurate winding loss calculation in high-frequency environments, increased losses due to winding height mismatch, and complex losses caused by harmonic currents.

[0091] Furthermore, an embodiment of the present invention also provides a transformer winding loss calculation device, the device including a processor and a memory:

[0092] The memory is used to store program code and transmit the program code to the processor;

[0093] The processor is configured to execute the steps of the transformer winding loss calculation method as described in the above method embodiment according to the instructions in the program code.

[0094] Furthermore, an embodiment of the present invention also provides a computer-readable storage medium, which is used to store program code, and the program code is used to execute the transformer winding loss calculation method described in the above method embodiment.

[0095] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0096] In the several embodiments provided by the present invention, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be through some interface, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0097] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0098] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0099] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the various embodiments of the method of the present invention. The aforementioned storage medium includes various media that can store program code, such as USB flash drives, mobile hard drives, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical disks.

[0100] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for calculating transformer winding loss, characterized in that: include: Obtain the harmonic current of the environment where the transformer winding is located; Calculating the AC resistance of the transformer winding based on the harmonic current through skin effect and proximity effect; Obtaining a non-sinusoidal current in an environment where a transformer winding is located, and decomposing the non-sinusoidal current into a plurality of harmonic components; After adjusting the height of the transformer winding to be equal to the height of the core window based on a preset transformer winding design method, the frequency of each harmonic component is calculated respectively, and the total winding loss is calculated based on the frequency of the harmonic component and the AC resistance.

2. The transformer winding loss calculation method according to claim 1, characterized in that: The step of calculating the AC resistance of the transformer winding according to the harmonic current through the skin effect and the proximity effect includes: Based on Fourier decomposition theory, the harmonic current is decomposed into several frequency components, and the skin effect and proximity effect are analyzed and calculated for each of the frequency components to obtain the AC resistance of the winding; Wherein, the calculation expression of the AC resistance is: ； Where, is the AC resistance, is the DC resistance, is the AC-DC resistance ratio correction coefficient, is the frequency-dependent eddy current factor, is the operating frequency.

3. The transformer winding loss calculation method according to claim 1, characterized in that: The respectively calculating the frequencies of the harmonic components comprises: Based on Fourier decomposition theory, the non-sinusoidal current is decomposed into several harmonic components; Calculate the frequency of each harmonic component based on a frequency calculation formula; Wherein, the frequency calculation formula is: ； Where, is the frequency of the harmonic component, is the operating frequency, is the harmonic order.

4. The transformer winding loss calculation method according to claim 3, characterized in that: The calculating of the total winding loss according to the frequency of the harmonic component and the AC resistance includes: Calculating harmonic component loss based on the frequency of the harmonic component and the AC resistance based on a loss calculation formula; Adding the losses of the harmonic components to obtain the total winding loss; The loss calculation formula is: ； Where, is the harmonic component loss, For the The current amplitude of the order harmonic, is the AC resistance at the frequency corresponding to the harmonic component.

5. The transformer winding loss calculation method according to claim 1, characterized in that: The preset transformer winding design method adjusts the height of the transformer winding to be equal to the height of the magnetic core window, including: determining a type of an initial winding for designing a winding, the type of the initial winding comprising: a segmented conductor; Through the gap factor folding the initial winding into a copper foil winding having the same geometric height as the initial winding; Through the gap factor The copper foil winding is folded into a copper foil winding having a height equal to that of the magnetic core window.

6. The transformer winding loss calculation method according to claim 5, characterized in that: The gap factor The expression is: ； Where, is the number of segments of a layer of winding, is the height of a single-layer winding, is the total height of one layer of winding.

7. The transformer winding loss calculation method according to claim 5, characterized in that: The gap factor The expression is: ； Where, is the total height of one layer of winding, is the core window height.

8. The transformer winding loss calculation method according to claim 5, characterized in that: Also includes: By the gap factor and the gap factor The conductivity of the winding is modified. The expression of the modified conductivity of the winding is: ； Where, is the conductivity of the winding after the winding modification, and is the gap factor, is the penetration ratio of the winding after converting the total gap factor, is the conductivity of the winding before winding modification.

9. A transformer winding loss calculation device, characterized in that: The device includes a processor and a memory: The memory is used to store program code and transmit the program code to the processor; The processor is configured to execute the transformer winding loss calculation method according to any one of claims 1 to 8 according to instructions in the program code.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium is used to store program code, and the program code is used to execute the transformer winding loss calculation method according to any one of claims 1 to 8.

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