Balancing winding design method of transformer and transformer

Abstract

The invention discloses a transformer balance winding design method and a transformer, the transformer comprises a first primary winding, a balance winding, a secondary winding and a second primary winding which are laid in sequence from inside to outside, one end of the balance winding is connected with one end of the second primary winding, and the other end of the second primary winding is connected with the first primary winding; the balance winding design method comprises the steps of obtaining a first structure capacitance between a second primary winding and a secondary winding, a second structure capacitance between a balance winding and the secondary winding, the number of turns of the second primary winding and the number of turns of the secondary winding; and calculating the number of turns of the balance winding according to the first structure capacitor, the second structure capacitor, the number of turns of the second primary winding and the number of turns of the secondary winding. Through staggered winding, leakage inductance and power loss of the transformer are reduced, the number of turns of the balance winding is obtained through simple calculation, time is shortened, and calculation errors are reduced; the transformer is provided with a balance winding to reduce conduction noise and reduce the size of the transformer.

Description

Technical Field

[0001] The present invention relates to the field of transformers, and in particular to a balanced winding design method for a transformer and a transformer. Background Art

[0002] In isolated switching power supplies, the common-mode electromagnetic interference (EMI) characteristics of the transformer are an important indicator for judging its electromagnetic compatibility performance. With the promotion and application of silicon carbide (SiC) devices and wide-bandgap power electronic devices, the switching frequency and resonant frequency of the switching power supply have been improved, which makes the common-mode EMI characteristics of the transformer a direct factor in determining the quality of electromagnetic compatibility performance.

[0003] The conventional shielding method for flyback converters is to add a single layer of shielding copper foil between the primary and secondary windings of the transformer and connect it to the input positive busbar, but this method requires adjusting the negative induced charge generated by the primary side in the secondary winding by constantly changing the window height of the copper foil to offset the common-mode noise. However, for flyback converters that use synchronous rectification on the secondary side, the common-mode current of the negative charge induced on the secondary winding of the transformer is superimposed due to the low position of the moving point, so the common-mode noise cannot be offset. For this situation, a common method is to add an external reverse auxiliary winding to reduce the position of the shielding copper foil, but this approach is not conducive to reducing the size and cost of the transformer, and the leakage inductance is also relatively large, which increases the loss of the transformer. Summary of the invention

[0004] The embodiment of the present invention provides a balanced winding design method for a transformer and a transformer, so as to solve the problems of transformer leakage inductance, large volume and high cost in a conventional shielding method.

[0005] Based on the above purpose, in one embodiment, a balanced winding design method for a transformer is provided, wherein the transformer comprises a first primary winding, a balanced winding, a secondary winding, and a second primary winding arranged in sequence from the inside to the outside, one end of the balanced winding is connected to one end of the second primary winding, and the other end of the second primary winding is connected to the first primary winding; the balanced winding design method comprises: Acquire a first structural capacitance between the second primary winding and the secondary winding, a second structural capacitance between the balance winding and the secondary winding, the number of turns of the second primary winding, and the number of turns of the secondary winding; The number of turns of the balance winding is calculated according to the first structural capacitor, the second structural capacitor, the number of turns of the second primary winding, and the number of turns of the secondary winding.

[0006] In one embodiment, the calculation expression for the number of turns of the balance winding is calculated according to the first structure capacitor, the second structure capacitor, the number of turns of the second primary winding, and the number of turns of the secondary winding as follows: , in, is the number of turns of the balance winding, is the first structural capacitance, is the second structure capacitance, is the number of turns of the second primary winding, is the number of turns of the secondary winding.

[0007] In one embodiment, the balance winding is wound around the entire longitudinal window space of the transformer, so that the winding height of the balance winding is equal to the winding heights of the secondary winding and the second primary winding.

[0008] In one embodiment, obtaining the first structural capacitance includes: Acquire a coil radius of the secondary winding, a winding height of the secondary winding, and a first inter-layer distance between the second primary winding and the secondary winding; The first structural capacitance is calculated according to the coil radius of the secondary winding, the winding height of the secondary winding, and a first inter-layer distance between the second primary winding and the secondary winding.

[0009] In one embodiment, the calculation expression for calculating the capacitance of the first structure is: , in, is the first structural capacitance, is the vacuum dielectric constant, is the equivalent dielectric constant of the interlayer insulation material of the second primary winding and the secondary winding, is the coil radius of the secondary winding, is the winding height of the secondary winding, is the first inter-layer distance.

[0010] In one embodiment, obtaining the second structural capacitance includes: Obtaining a coil radius of the balance winding, a winding height of the secondary winding, and a second inter-layer distance between the balance winding and the secondary winding; The second structural capacitance is calculated according to the coil radius of the balance winding, the winding height of the secondary winding, and the second inter-layer distance between the balance winding and the secondary winding.

[0011] In one embodiment, the calculation expression for obtaining the capacitance of the second structure is: , in, is the second structure capacitance, is the vacuum dielectric constant, is the equivalent dielectric constant of the interlayer insulation material of the balance winding and the secondary winding, is the coil radius of the balance winding, is the winding height of the secondary winding, is the second inter-layer distance.

[0012] In one embodiment, the number of turns of the balance winding is calculated according to the first structure capacitor, the second structure capacitor, the number of turns of the second primary winding, and the number of turns of the secondary winding, including: Calculating the sum of the number of turns of the first primary winding and the number of turns of the second primary winding to obtain the number of turns of the total primary winding; determining a first functional relationship between a first displacement current and the first structural capacitance, the number of turns of the total primary winding, the number of turns of the second primary winding, and the number of turns of the secondary winding; determining a second functional relationship between a second displacement current and the second structural capacitance, the number of turns of the total primary winding, the number of turns of the balance winding, and the number of turns of the secondary winding; Determine a corresponding relationship between the total displacement current of the transformer and the first functional relationship and the second functional relationship; According to the first functional relationship, the second functional relationship and the corresponding relationship, the total displacement current of the transformer is set to zero, and the number of turns of the balance winding is obtained.

[0013] In one embodiment, a transformer is provided, comprising a first primary winding, a balance winding, a secondary winding, and a second primary winding arranged in sequence from the inside to the outside, one end of the balance winding is connected to one end of the second primary winding, the other end of the second primary winding is connected to the first primary winding, and the balance winding is obtained using the above-mentioned balance winding design method.

[0014] In one embodiment, the transformer further includes insulating tape disposed between each layer of windings, the second primary winding and the secondary winding both fully wind around the longitudinal window space of the transformer, and the winding height of the balance winding is equal to the winding height of the second primary winding and the secondary winding.

[0015] The above-mentioned balanced winding design method and transformer of a transformer realize staggered winding by laying the windings in sequence from the inside to the outside, thereby reducing the leakage inductance of the transformer and reducing the power loss of the transformer at the same time. A specific balanced winding is set according to the first structural capacitor, the second structural capacitor, the number of turns of the second primary winding and the number of turns of the secondary winding, which can not only shield the electric field coupling effect of the primary and secondary sides, but also realize the function of completely balancing the common-mode displacement current of the primary and secondary sides of the transformer. Combined with staggered winding, the conducted noise can be reduced. Compared with the traditional setting of a single-layer shielding copper foil and an additional reverse winding, the volume of the transformer can be reduced and the manufacturing cost can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0017] Figure 1 is a schematic diagram of the windings of each winding of a transformer in one embodiment of the present invention; Figure 2 is a displacement current interference transmission path diagram in one embodiment of the present invention; Figure 3 is a flow chart of a balanced winding design method in one embodiment of the present invention; Figure 4 It is a schematic diagram of a traditional low-end synchronous rectifier flyback converter with a single layer of copper foil and an external reverse winding to balance the displacement current; Figure 5 is a flow chart for obtaining the number of turns of a balanced winding in a balanced winding design method in one embodiment of the present invention; Figure 6 It is a schematic diagram of voltage values ​​corresponding to different winding heights in one embodiment of the present invention.

[0018] Figure numerals: 1. Terminal No. 1 of the transformer, 2. Terminal No. 2 of the transformer, 3. Terminal No. 3 of the transformer, 4. Terminal No. 4 of the transformer, 5. Terminal No. 5 of the transformer, 6. Terminal No. 6 of the transformer, 7. Insulating tape. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.

[0020] It should be understood that the present invention can be implemented in different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, providing these embodiments will make the disclosure thorough and complete and fully convey the scope of the present invention to those skilled in the art. In the accompanying drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. The same reference numerals throughout represent the same elements.

[0021] It should be understood that when an element or layer is referred to as being "on, adjacent to, connected to or coupled to other elements or layers, it may be directly on, adjacent to, connected to or coupled to other elements or layers, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on, directly adjacent to, directly connected to or directly coupled to other elements or layers, there may be no intervening elements or layers. It should be understood that, although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present invention, the first element, component, region, layer or part discussed below may be represented as a second element, component, region, layer or part.

[0022] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," and the like may be used herein for ease of description to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that the spatially relative terms are intended to include different orientations of the device in use and operation in addition to the orientations shown in the figures. For example, if the device in the accompanying drawings is flipped, then the elements or features described as "under other elements" or "under" or "under" will be oriented as "on" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0023] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present invention. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0024] In order to fully understand the present invention, detailed structures and steps will be presented in the following description to illustrate the technical solutions proposed by the present invention. The preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other implementations.

[0025] In one embodiment, a method for designing a balanced winding of a transformer is provided, such as Figure 1 and Figure 2 As shown, the transformer includes a first primary winding arranged from inside to outside. , Balance winding , Secondary Winding , the second primary winding , the balance winding One end of the second primary winding One end of the second primary winding is connected to The other end of the first primary winding connected; such as Figure 3 As shown, the balanced winding design method includes: S101, obtaining the second primary winding and the secondary winding The first structure capacitance between , the balance winding and the secondary winding The second structure capacitance between , the second primary winding Number of turns and the secondary winding Number of turns ; Among them, the balanced winding can not only shield the electric field coupling between the primary and secondary sides, but also realize the function of completely balancing the common-mode displacement current of the primary and secondary sides of the transformer; like Figure 2 As shown, the first structure capacitance Refers to the second primary winding and the secondary winding The equivalent capacitance between the second structure capacitance Balanced winding and the secondary winding The equivalent capacitance between the first structure and the The second primary winding and the secondary winding The equivalent capacitance coupled to the second structure capacitance For balanced winding and the secondary winding Equivalent capacitance coupled to, first structure capacitance and the second structure capacitance These are not actual capacitor settings.

[0026] S102, according to the first structure capacitor The second structure capacitor , the number of turns of the second primary winding and the number of turns of the secondary winding Calculate the number of turns of the balance winding .

[0027] Among them, the first structure capacitance obtained is , the second structure capacitor , the number of turns of the second primary winding and the number of turns of the secondary winding Substituting the first structural capacitor, the second structural capacitor, the number of turns of the second primary winding, the number of turns of the secondary winding and the number of turns of the balance winding into the relationship model, the number of turns of the balance winding is obtained.

[0028] like Figure 1 As shown, an auxiliary winding is also provided in the transformer , auxiliary winding Located in the first primary winding The outer and balance windings On the inner side of the transformer, each winding is arranged in an interlaced manner.

[0029] In this embodiment, the staggered winding is achieved by laying the windings in sequence from the inside to the outside, making full use of the space between the windings, making the structure of the transformer more compact, and reducing electromagnetic wave interference, and reducing the leakage inductance of the transformer and reducing power loss. According to the first structure capacitor, the second structure capacitor, the number of turns of the second primary winding and the number of turns of the secondary winding, a specific balanced winding is set, which can not only shield the electric field coupling effect of the primary and secondary sides, but also realize the function of completely balancing the common mode displacement current of the primary and secondary sides of the transformer. Combined with the staggered winding, the conducted noise can be reduced. Figure 4 As shown, compared with the traditional arrangement of a single-layer shielding copper foil and an additional reverse winding, the volume of the transformer can be reduced and the manufacturing cost can be reduced.

[0030] In one embodiment, the calculation expression for the number of turns of the balance winding is calculated according to the first structure capacitor, the second structure capacitor, the number of turns of the second primary winding, and the number of turns of the secondary winding as follows: , in, is the number of turns of the balance winding, is the first structural capacitance, is the second structure capacitance, is the number of turns of the second primary winding, is the number of turns of the secondary winding.

[0031] Among them, the electric field strength in the transformer winding is closely related to the number of turns of the winding. The more turns, the greater the electric field strength. Since the structural capacitance is proportional to the electric field strength, the increase in electric field strength will lead to an increase in the capacitance effect between the windings.

[0032] In this embodiment, the number of turns of the balancing winding is calculated based on the first structural capacitor, the second structural capacitor, the number of turns of the second primary winding, and the number of turns of the secondary winding, so that the calculation is more accurate, the error and uncertainty in the design process are reduced, the electromagnetic compatibility of the transformer can be changed, and it helps to reduce the electromagnetic interference of the transformer and improve the service life and safety of the transformer; by adjusting the number of turns, the manufacturing process of the transformer is simplified to meet different needs.

[0033] In one embodiment, if Figure 1 As shown, the balanced winding The transformer is wound around the longitudinal window space to make the balanced winding The winding height is equal to the secondary winding and the second primary winding Winding height.

[0034] Among them, Figure 1 As shown, the longitudinal window space refers to the area on the transformer core used for winding coils, that is, the space provided in the longitudinal direction. The winding height refers to the longitudinal vertical distance from the starting end to the ending end of the coil on the transformer core frame, and can also refer to the cumulative height of the winding turns, which has the same meaning as the longitudinal window space and winding height that appear below, and will not be repeated hereafter.

[0035] Balanced winding The winding height refers to the vertical distance from the starting end to the ending end of the balanced winding on the transformer core frame, or it can be the cumulative height of all turns of the balanced winding on the core frame. , Secondary Winding and the second primary winding The longitudinal window space of the transformer is fully wound, and the winding heights of the balance winding, the secondary winding and the second primary winding are equal.

[0036] In this embodiment, the balance winding, the secondary winding and the second primary winding are all wound around the longitudinal window of the transformer to ensure that the magnetic flux is evenly distributed between the windings, thereby improving the electromagnetic conversion efficiency, and can also effectively reduce the generation of electromagnetic (EMI) and improve the electromagnetic compatibility of the transformer. The compact winding design can reduce the problem of uneven distribution of current in the winding, thereby reducing energy loss, and can also maintain stable output of current and voltage, thereby ensuring the reliability of the transformer during long-term operation.

[0037] In one embodiment, in the above step S101, obtaining the first structural capacitance includes: Acquire a coil radius of the secondary winding, a winding height of the secondary winding, and a first inter-layer distance between the second primary winding and the secondary winding; The calculation expression of the first structural capacitance is calculated according to the coil radius of the secondary winding, the winding height of the secondary winding, and the first interlayer distance between the second primary winding and the secondary winding: , in, is the first structural capacitance, is the vacuum dielectric constant, is the equivalent dielectric constant of the insulating material between the second primary winding and the secondary winding, is the coil radius of the secondary winding, is the winding height of the secondary winding, is the first inter-layer distance.

[0038] In this embodiment, by establishing a relationship model for representing the first structural capacitance and the coil radius of the secondary winding, the winding height of the secondary winding and the first layer inter-layer distance, after substituting the parameters into the relationship model, the first structural capacitance can be accurately calculated, so as to more accurately obtain the number of turns of the balanced winding, deepen the shielding effect of the balanced winding and the effect of offsetting the common-mode displacement current.

[0039] In one embodiment, in the above step S101, obtaining the second structural capacitance includes: Obtaining a coil radius of the balance winding, a winding height of the secondary winding, and a second inter-layer distance between the balance winding and the secondary winding; The calculation expression of the second structure capacitance is calculated according to the coil radius of the balance winding, the winding height of the secondary winding, and the second interlayer distance between the balance winding and the secondary winding: , in, is the second structure capacitance, is the vacuum dielectric constant, is the equivalent dielectric constant of the interlayer insulation material of the balance winding and the secondary winding, is the coil radius of the balance winding, is the winding height of the secondary winding, is the second inter-layer distance.

[0040] In this embodiment, by establishing a relationship model for representing the second structural capacitance and the coil radius of the balance winding, the winding height of the secondary winding and the second layer distance, after substituting the parameters into the relationship model, the second structural capacitance can be accurately calculated to more accurately obtain the number of turns of the balance winding, deepen the shielding effect of the balance winding and the effect of offsetting the common-mode displacement current.

[0041] In one embodiment, that is, in the above step S102, if Figure 5 As shown, the number of turns of the balance winding is calculated according to the first structure capacitor, the second structure capacitor, the number of turns of the second primary winding, and the number of turns of the secondary winding, including: S801, calculating the sum of the number of turns of the first primary winding and the number of turns of the second primary winding to obtain the number of turns of the total primary winding; The number of turns of the total primary winding is the sum of the number of turns of the first primary winding and the number of turns of the second primary winding.

[0042] S802, determining a first functional relationship between a first displacement current and the first structural capacitance, the number of turns of the total primary winding, the number of turns of the second primary winding, and the number of turns of the secondary winding; Among them, the first functional relationship is: , in, is the first displacement current, is the core skeleton height, is the first structure capacitance, is the total number of primary winding turns, is the number of turns of the second primary winding, is the number of turns of the secondary winding, is the voltage amplitude generated by the primary moving point when the switch changes, is the time for the winding potential to change, is the winding height of the secondary winding; the above functional relationship indicates that: when the winding height is Within the range, integrate the voltage corresponding to the winding height and then multiply it by , the first displacement current can be obtained The average value of the corresponding voltage amplitude is multiplied by To obtain the winding height The corresponding electric potential is exist within the range.

[0043] S803, determining a second functional relationship between the second displacement current and the second structural capacitance, the number of turns of the total primary winding, the number of turns of the balance winding, and the number of turns of the secondary winding; Among them, the second functional relationship is: , in, is the second displacement current, is the core skeleton height, is the second structure capacitance, is the total number of primary winding turns, is the number of turns of the balancing winding, is the number of turns of the secondary winding, is the voltage amplitude generated by the primary moving point when the switch changes, is the time for the winding potential to change, is the winding height of the secondary winding.

[0044] S804, determining a correspondence between the total displacement current of the transformer and the first functional relationship and the second functional relationship; Among them, the corresponding relationship is: , in, is the total displacement current of the transformer, is the first displacement current, is the second displacement current.

[0045] S805: According to the first functional relationship, the second functional relationship and the corresponding relationship, the total displacement current of the transformer is set to zero, and the number of turns of the balance winding is calculated.

[0046] In which, the total displacement current of the transformer is set to zero, and we can get , because the balanced winding , Secondary Winding and the second primary winding They are tightly wound to fill the entire transformer window space, so the interlayer dielectric of the windings can be approximately considered equal, both are insulating tape and winding paint, that is, , combined with the above first functional relationship and the second functional relationship, the calculation expression of the number of turns of the balance winding can be obtained as follows: .

[0047] Since the transformer winding is made up of multiple turns of wire, different layers are produced during winding. When there is an insulating medium between adjacent layers, structural capacitance will be formed. Figure 2 As shown in , when the electric field between the transformer windings changes, displacement current will be generated. Since the structural capacitance plays a key role in the electric field change process, the size and distribution of the structural capacitance will directly affect the size and distribution of the displacement current. Figure 1 and Figure 2 As shown, since displacement current will be generated between adjacent windings, the auxiliary winding and the secondary winding between and the first primary winding and the secondary winding A common mode displacement current will be generated between the auxiliary windings. and the secondary winding and the first primary winding and the secondary winding They are all connected to the primary power ground, so the displacement common mode current between them will flow back in the primary power loop and will not be displaced to the secondary side to generate common mode noise; Because the balanced winding shielding effect, so only the second primary winding and the secondary winding and balanced winding and the secondary winding A common-mode displacement current will be generated between them; Therefore, if Figure 2 As shown, the total displacement current of the transformer consists of only the first displacement current and the second displacement current, and the current directions of the two are opposite. The first displacement current is the second primary winding and the secondary winding The displacement current between the two windings is the second displacement current. and the secondary winding The displacement current between .

[0048] The displacement current between the windings is induced by the pulsating voltage generated on the structural capacitance between the windings. By dividing the adjacent windings into small segments, the length of each segment is , and the structural capacitance corresponding to each segment is , the displacement current induced by the structural capacitance between adjacent windings can be calculated. This process is achieved through integration. , in, is the displacement current, is the voltage amplitude generated by the primary moving point of the corresponding segment when the switch changes, is the time of the corresponding segment, is the structural capacitance of the corresponding segment.

[0049] like Figure 6 As shown in the figure, the horizontal axis refers to the voltage corresponding to each winding at different winding heights, and the vertical axis refers to different winding heights. Figure 6 By integrating the horizontal and vertical coordinates of , we can get the first functional relationship and the second functional relationship.

[0050] In this embodiment, the number of turns of the balance winding is obtained by calculation, so that the calculation result is more accurate, which can reduce errors and uncertainties in the design process, improve the electromagnetic compatibility of the transformer, reduce the electromagnetic interference of the transformer, and improve the service life and safety of the transformer; by adjusting the number of turns of the balance winding, the manufacturing process of the transformer is simplified to meet different usage requirements.

[0051] In one embodiment, a transformer is provided, such as Figure 1 As shown, the transformer includes a first primary winding arranged from inside to outside. , Balance winding , Secondary Winding , the second primary winding , the balance winding One end of the second primary winding One end of the second primary winding is connected to The other end of the first primary winding connected, the balance winding It is obtained by adopting the above-mentioned balanced winding design method.

[0052] Among them, the balance winding One end is connected to one end of the second primary winding, that is, terminal 2 of the transformer, and the other end is left hanging. Each winding is wound in an interlaced manner.

[0053] In this embodiment, a balancing winding is provided in the transformer to balance the displacement current between the primary and secondary sides of the transformer and shield the electric field coupling between the primary and secondary sides. At the same time, staggered winding is adopted between the windings to reduce the leakage inductance of the transformer, reduce power loss and conduction noise. Compared with the traditional setting of a single-layer shielding copper foil and an additional reverse winding, the size of the transformer can be reduced and the production cost can be reduced.

[0054] In one embodiment, the transformer further includes an insulating tape 7 arranged between each layer of windings, the second primary winding and the secondary winding both fully wind the longitudinal window space of the transformer, and the winding height of the balance winding is equal to the winding height of the second primary winding and the secondary winding.

[0055] The insulating tape 7 arranged between each layer of windings is a double-layer insulating tape.

[0056] In this embodiment, a double layer of insulating tape is used between each winding of the transformer, which can enhance the insulation strength between the windings, isolate the windings, ensure the independent operation of each winding without interfering with each other, and reduce the loss of current, reduce losses, and improve the efficiency of the transformer. The winding heights of the second primary winding, the secondary winding, and the balance winding are set to be equal, and all are wound around the longitudinal window space of the transformer, so that the coupling between the winding layers is tighter, which can reduce leakage inductance, improve the efficiency of the transformer, and reduce the temperature rise and noise of the transformer, and improve the operating stability of the transformer. The fully wound transformer can also reduce the volume and weight of the transformer, reduce manufacturing costs, and facilitate installation and maintenance.

[0057] The embodiments described above 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 the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A method for designing a balanced winding of a transformer, characterized in that: The transformer comprises a first primary winding, a balance winding, a secondary winding, and a second primary winding arranged in sequence from the inside to the outside, one end of the balance winding is connected to one end of the second primary winding, and the other end of the second primary winding is connected to the first primary winding; The balanced winding design method comprises: Acquire a first structural capacitance between the second primary winding and the secondary winding, a second structural capacitance between the balance winding and the secondary winding, the number of turns of the second primary winding, and the number of turns of the secondary winding; The number of turns of the balance winding is calculated according to the first structural capacitor, the second structural capacitor, the number of turns of the second primary winding, and the number of turns of the secondary winding.

2. The balanced winding design method according to claim 1, characterized in that: The calculation expression for the number of turns of the balance winding is calculated according to the first structure capacitor, the second structure capacitor, the number of turns of the second primary winding, and the number of turns of the secondary winding as follows: ， in, is the number of turns of the balance winding, is the first structural capacitance, is the second structure capacitance, is the number of turns of the second primary winding, is the number of turns of the secondary winding.

3. The balanced winding design method according to claim 1, characterized in that: The balance winding is wound around the entire longitudinal window space of the transformer, so that the winding height of the balance winding is equal to the winding heights of the secondary winding and the second primary winding.

4. The balanced winding design method according to claim 1, characterized in that: Obtaining the first structural capacitance includes: Acquire a coil radius of the secondary winding, a winding height of the secondary winding, and a first inter-layer distance between the second primary winding and the secondary winding; The first structural capacitance is calculated according to the coil radius of the secondary winding, the winding height of the secondary winding, and a first inter-layer distance between the second primary winding and the secondary winding.

5. The balanced winding design method according to claim 4, characterized in that: The calculation expression of the capacitance of the first structure is calculated as follows: ， in, is the first structural capacitance, is the vacuum dielectric constant, is the equivalent dielectric constant of the interlayer insulation material of the second primary winding and the secondary winding, is the coil radius of the secondary winding, is the winding height of the secondary winding, is the first inter-layer distance.

6. The balanced winding design method according to claim 1, characterized in that: Obtaining the second structural capacitance includes: Obtaining a coil radius of the balance winding, a winding height of the secondary winding, and a second inter-layer distance between the balance winding and the secondary winding; The second structural capacitance is calculated according to the coil radius of the balance winding, the winding height of the secondary winding, and the second inter-layer distance between the balance winding and the secondary winding.

7. The balanced winding design method according to claim 6, characterized in that: The calculation expression of the capacitance of the second structure is calculated as follows: ， in, is the second structure capacitance, is the vacuum dielectric constant, is the equivalent dielectric constant of the interlayer insulation material of the balance winding and the secondary winding, is the coil radius of the balance winding, is the winding height of the secondary winding, is the second inter-layer distance.

8. The balanced winding design method according to claim 1, characterized in that: The number of turns of the balance winding is calculated according to the first structure capacitor, the second structure capacitor, the number of turns of the second primary winding, and the number of turns of the secondary winding, including: Calculating the sum of the number of turns of the first primary winding and the number of turns of the second primary winding to obtain the number of turns of the total primary winding; determining a first functional relationship between a first displacement current and the first structural capacitance, the number of turns of the total primary winding, the number of turns of the second primary winding, and the number of turns of the secondary winding; determining a second functional relationship between a second displacement current and the second structural capacitance, the number of turns of the total primary winding, the number of turns of the balance winding, and the number of turns of the secondary winding; Determine a corresponding relationship between the total displacement current of the transformer and the first functional relationship and the second functional relationship; According to the first functional relationship, the second functional relationship and the corresponding relationship, the total displacement current of the transformer is set to zero, and the number of turns of the balance winding is obtained.

9. A transformer, characterized in that: The transformer includes a first primary winding, a balance winding, a secondary winding, and a second primary winding arranged in sequence from the inside to the outside, one end of the balance winding is connected to one end of the second primary winding, and the other end of the second primary winding is connected to the first primary winding. The balance winding is obtained using the balance winding design method described in any one of claims 1 to 8.

10. A transformer according to claim 9, characterized in that: The transformer also includes an insulating tape arranged between each layer of windings. The second primary winding and the secondary winding both wind around the entire longitudinal window space of the transformer. The winding height of the balance winding is equal to the winding height of the second primary winding and the secondary winding.

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