Coil design method, coil, and transformer

Abstract

This invention discloses a coil design method, a coil, and a transformer. The method includes dividing the coil into at least a first coil and a second coil; and placing the second coil above the first coil along the height direction of the transformer. The first coil is made of a first conductor, and the second coil is made of a second conductor. The width of the second conductor is greater than the width of the first conductor, and / or the thickness of the second conductor is greater than the thickness of the first conductor. This invention can reduce temperature unevenness in the coil, improve the overall temperature rise of the coil, increase material utilization, reduce costs, improve the operating quality of the transformer, and extend the service life of the coil.

Description

Technical Field

[0001] This invention relates to the field of power equipment, and in particular to a coil design method, a coil, and a transformer. Background Technology

[0002] The coil is the electrical component in a transformer responsible for inputting and outputting electrical energy; it is a crucial part of the transformer. During operation, both copper and iron losses are converted into heat and dissipated. To cool the coil, it is typically immersed in an oil tank. Based on the principle that hot oil rises and cold oil sinks, the oil temperature at the top of the tank is always higher than at the bottom, usually about 20% higher than the average. Consequently, the temperature of the upper coil is always higher than that of the lower coil, resulting in uneven coil temperature. Summary of the Invention

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a coil design method, a coil, and a transformer that can improve temperature rise.

[0004] According to a first aspect of the present invention, a coil design method is provided for manufacturing coils of a transformer, comprising:

[0005] The coil is divided into at least a first coil and a second coil;

[0006] Along the height direction of the transformer, the second coil is positioned above the first coil. The first coil is made of a first wire, and the second coil is made of a second wire. The width of the second wire is greater than the width of the first wire, and / or the thickness of the second wire is greater than the thickness of the first wire.

[0007] Preferably, the coil parameters of the first coil and the second coil are calculated according to a preset coefficient K, wherein the preset coefficient K is selected according to the capacity of the transformer.

[0008] Preferably, the coil parameters include the current density J of the coil, and the calculation of the coil parameters of the first coil and the second coil according to a preset coefficient K includes:

[0009] The current density of the first coil is obtained based on the current density formula J=I / A of the coil and the preset coefficient K. =(I / A)*1 / K, and the current density of the second coil. =(I / A)*K, where I is the phase current data of the coil, and A is the cross-sectional area data of the coil. and stated satisfy: / = .

[0010] Preferably, the coil parameters include the cross-sectional area A of the coil, and the calculation of the coil parameters of the first coil and the second coil according to a preset coefficient K further includes:

[0011] The cross-sectional area of ​​the first coil is obtained according to the formula A=I / J for the cross-sectional area of ​​the coil and the preset coefficient K. =I / and the cross-sectional area of ​​the second coil =I / ;

[0012] Based on the cross-sectional area of ​​the first coil =I / The cross-sectional area of ​​the second coil =I / and the / = , to obtain the and stated satisfy: / = .

[0013] Preferably, the coil parameters include the length L of the coil, and the calculation of the coil parameters of the first coil and the second coil according to a preset coefficient K includes:

[0014] According to the coil length formula L= The length of the first coil is obtained by using W and the preset coefficient K. = W*K, and the length of the second coil = W*(1 / K), the The average turn length of the coil is given by W, and the total number of turns of the coil is given by W. and stated satisfy: / = .

[0015] Preferably, the coil parameters include the weight G of the coil, and the calculation of the coil parameters of the first coil and the second coil according to a preset coefficient K further includes:

[0016] The weight of the first coil is obtained using the coil weight formula G=3LAg. =3 g, and the weight of the second coil =3 g, where g is the material density of the coil;

[0017] Based on the weight of the first coil =3 g. Weight of the second coil =3 g, the aforementioned / = and the / = , to obtain the and stated satisfy: / = .

[0018] Preferably, the coil parameters include the load loss of the coil. The step of calculating the coil parameters of the first coil and the second coil according to the preset coefficient K further includes:

[0019] The resistance of the first coil is obtained according to the formula R=ρ(L / A). =ρ( ), and the resistance of the second coil. =ρ( );

[0020] According to the formula for the resistance loss of the coil = =3 The load loss of the first coil is obtained by using R and the preset coefficient K. =3 *(1 / K), and the load loss of the second coil. =3 *K;

[0021] Based on the load loss of the first coil =3 (1 / K), Load loss of the second coil =3 K, the resistance of the first coil =ρ( The resistance of the second coil =ρ( ),get / =( / () / )* ;

[0022] According to the above / =( / () / )* The above / = and the / = , to obtain the and stated satisfy: / = .

[0023] Preferably, the coil parameters include the thermal load Q of the coil, and the calculation of the coil parameters of the first coil and the second coil according to a preset coefficient K further includes:

[0024] According to the heat load formula of the coil, Q=1.032 / S, to obtain the heat load of the first coil =1.032 / S*(1 / K), and the thermal load of the second coil =1.032 / S*K, where S is the effective heat dissipation area of ​​the coil;

[0025] According to the heat load of the first coil =1.032 / S*(1 / K), the heat load of the second coil =1.032 / S*K and / = , to obtain the and satisfy: / = .

[0026] According to a second aspect of the invention, a coil is provided for a transformer, the coil comprising a first coil and a second coil, the second coil being disposed above the first coil along the height direction of the transformer, the first coil being made of a first conductor, the second coil being made of a second conductor, the width of the second conductor being greater than the width of the first conductor, and / or the thickness of the second conductor being greater than the thickness of the first conductor.

[0027] According to a third aspect of the present invention, a transformer is provided, comprising the coil disclosed in the second aspect of the present invention.

[0028] The coil design method according to embodiments of the present invention has at least the following beneficial effects:

[0029] This invention utilizes a conductor with greater width and / or greater thickness to create a second coil located at a higher oil temperature. This increases the heat dissipation area of ​​the second coil and reduces the current density, effectively lowering the temperature at that location. This reduces temperature unevenness in the coil, improves the overall temperature rise of the coil, increases material utilization, reduces costs, improves the operating quality of the transformer, and extends its service life.

[0030] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0032] Figure 1 This is a flowchart illustrating the steps of an embodiment of a coil design method according to the present invention;

[0033] Figure 2 This is a flowchart illustrating the steps of another embodiment of the coil design method of the present invention;

[0034] Figure 3 This is a schematic diagram of an embodiment of the coil of the present invention;

[0035] Figure 4 This is a schematic diagram of the structure of a coil embodiment of the present invention;

[0036] Figure 5 This is a schematic diagram of another coil embodiment of the present invention.

[0037] Figure label:

[0038] First coil 100; first wire 110; second coil 200; second wire 210. Detailed Implementation

[0039] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0040] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, inside, outside, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0041] In the description of this invention, the use of "first" and "second" is for the purpose of distinguishing technical features only, and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of the technical features indicated.

[0042] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0043] As is well known, traditional transformer coil designs use wires with the same current density and specifications for calculating heat dissipation area and temperature rise. While traditional calculation methods and winding processes are simple and easy to implement, they only calculate the average temperature rise of the coil, neglecting to calculate the temperature rise of the hottest spot. Consequently, during transformer operation, as the hot spot temperature continuously rises, uneven heat distribution occurs within the transformer, leading to excessively high temperatures at the hottest spots. This increases copper losses, severely impacts the coil's lifespan, and may even pose safety hazards to the transformer.

[0044] Therefore, some embodiments of the present invention propose a coil design method, as detailed in the accompanying drawings. Figures 1-3 As shown.

[0045] Reference Figure 1 The diagram illustrates a flowchart of an embodiment of a coil design method according to the present invention. In this embodiment, the coil design method includes:

[0046] Step S101: Divide the coil into at least a first coil 100 and a second coil 200; along the height direction of the transformer, place the second coil 200 above the first coil 100. The first coil 100 is made of a first conductor 110, and the second coil 200 is made of a second conductor 210. The width of the second conductor 210 is greater than the width of the first conductor 110, and / or the thickness of the second conductor 210 is greater than the thickness of the first conductor 110.

[0047] It is understood that the coil can be composed of a first coil 100 and a second coil 200, wherein the second coil 200 can be positioned above the first coil 100. The first coil 100 and the second coil 200 can be spliced ​​together or integrally formed. The upper-positioned second coil 200, compared to the first coil 100, can be made of a second conductor 210 with a wider width, a thicker thickness, or both. The difference in width and thickness between the first conductor 110 and the second conductor 210 can be specifically designed and selected by those skilled in the art. It should be noted that in this embodiment of the invention, a third coil and a fourth coil can also be provided; that is, the number of coil segments can be selected and set by those skilled in the art according to actual conditions, and this embodiment of the invention does not limit this.

[0048] Since the second coil 200 is located at the top and is immersed in the higher-temperature upper layer of oil, to reduce the temperature difference between the second coil 200 and the first coil 100, it is necessary to increase the heat dissipation performance of the second coil 200. Therefore, by selecting a second wire 210 with a greater width and / or thickness than the first wire 110 used to make the first coil 100, the heat dissipation area of ​​the coil surface can be increased, the current density inside the coil can be reduced, and the heat dissipation performance of the second coil 200 can be increased, allowing the second coil 200 to be effectively cooled even in the higher-temperature upper layer of oil. This embodiment of the invention uses a wire with a greater width and / or greater thickness to make the second coil 200 located at a higher oil temperature, thereby increasing the heat dissipation area of ​​the second coil 200 and reducing the current density, effectively reducing temperature unevenness in the coil, improving the overall temperature rise of the coil, increasing material utilization, reducing costs, improving the operating quality of the transformer, and extending its service life. (Refer to...) Figure 2 The diagram illustrates a flowchart of another embodiment of the coil design method of the present invention. In this embodiment, the coil design method includes:

[0049] Step S201: Divide the coil into at least a first coil 100 and a second coil 200; along the height direction of the transformer, place the second coil 200 above the first coil 100. The first coil 100 is made of a first conductor 110, and the second coil 200 is made of a second conductor 210. The width of the second conductor 210 is greater than the width of the first conductor 110, and / or the thickness of the second conductor 210 is greater than the thickness of the first conductor 110.

[0050] Step S202: Calculate the coil parameters of the first coil 100 and the second coil 200 according to the preset coefficient K, where the preset coefficient K is selected based on the transformer capacity.

[0051] In this embodiment of the invention, coil parameters may include data such as the overall or partial current density of the coil, coil cross-section, copper weight, heat load, and temperature rise. Based on the principle that the oil temperature in the upper layer of the tank is generally higher than that in the lower layer, and that the upper layer oil temperature is typically about 20% higher than the average oil temperature, this embodiment of the invention simplifies and facilitates the calculation of coil parameters by calculating and verifying multiple design schemes to obtain a preset coefficient K for the coil data. It should be noted that the value of the preset coefficient K is selected based on the transformer capacity, and those skilled in the art can choose according to the actual situation; this embodiment of the invention does not limit this selection.

[0052] In one embodiment, the coil parameters include the coil's current density J, and step S202 may include:

[0053] Based on the current density formula J=I / A and the preset coefficient K, the current density of the first coil 100 is obtained. =(I / A)*1 / K, and the current density of the second coil 200. =(I / A)*K, where I is the phase current of the coil, and A is the total cross-sectional area of ​​the coil. and satisfy: / = .

[0054] It should be noted that, in this embodiment of the invention, the calculation formula for coil current density is J=I / A, and a preset coefficient K is used, where J is the current density (A / mm²), I is the phase current (A), and A is the total cross-sectional area of ​​the coil (A / mm²). The current densities of the first coil 100 and the second coil 200 can be obtained respectively:

[0055] First coil current density 100: =(I / A)*1 / K (1;

[0056] Second coil current density 200: =(I / A)*K (2;

[0057] According to equations (1) and (2), we can obtain: / = (I / A) * 1 / K / (I / A) * K = / = (3).

[0058] It is understood that, in this embodiment of the invention, the total cross-sectional area of ​​the coil can be the size of the total cross-sectional area of ​​the wires used to make the coil. In this embodiment of the invention, the current density ratio of the first coil 100 and the second coil 200 can be calculated through the above calculation process, and used as the reference parameter for the design scheme of the two. In one example, the designer can select the size of the preset coefficient K according to the capacity of the transformer, such as K=0.85. According to the calculated formula (3), the current density of the first coil 100 is about 1.384 times that of the second coil 200. Based on this, the designer can design the coil according to this current density ratio. Specifically, the first coil 100 can be designed according to the design parameters of the standard coil, while the design parameters of the second coil 200 are calculated according to this current density ratio and the design parameters of the first coil 100. The design parameters of the second coil 200 are then calculated, and the second coil 200 is designed. This can reduce the current density of the second coil 200 immersed in the upper layer of oil, so that the temperature propagation during the operation of the coil is more uniform and the temperature rise phenomenon of the coil is improved.

[0059] In one embodiment, the coil parameters include the cross-sectional area A of the coil, and step S202 may include:

[0060] Based on the formula for the cross-sectional area of ​​a coil, A=I / J, and a preset coefficient K, the cross-sectional area of ​​the first coil 100 is obtained. =I / and the cross-sectional area of ​​the second coil 200 =I / ;

[0061] Based on the cross-sectional area of ​​the first coil 100 =I / The cross-sectional area of ​​the second coil 200 =I / as well as / = ,get and satisfy: / = .

[0062] It should be noted that, in this embodiment of the invention, the cross-sectional area of ​​the coil can be the size of the cross-sectional area of ​​the wire used to make the coil. According to the formula for the cross-sectional area of ​​a coil, A=I / J, the cross-sectional areas of the first coil 100 and the second coil 200 can be obtained respectively:

[0063] The cross-sectional area of ​​the first coil is 100: =I / (4);

[0064] The cross-sectional area of ​​the second coil is 200: =I / (5);

[0065] According to equations (4) and (5) and the preset coefficient K, we can obtain: / =(I / ) / (I / )= / = (6).

[0066] The embodiments of the present invention can calculate the cross-sectional area ratio of the first coil 100 and the second coil 200 through the above calculation process, and use this as the benchmark parameter for their design schemes. In one example, the designer can select the size of the preset coefficient K according to the transformer capacity, such as K=0.85. According to the calculated formula (6), the cross-sectional area of ​​the first coil 100 is about 0.723 times that of the second coil 200. Based on this, the designer can design the coil according to this cross-sectional area ratio. Specifically, the first coil 100 can be designed according to the design parameters of the standard coil, while the design parameters of the second coil 200 are calculated according to this cross-sectional area ratio and the design parameters of the first coil 100. The design parameters of the second coil 200 are then calculated, and the second coil 200 is designed. This can increase the cross-sectional area of ​​the second coil 200 immersed in the upper layer of oil, increase the heat dissipation area of ​​the second coil 200, improve the heat dissipation performance of the second coil 200, make the temperature spread more uniform during the operation of the coil, and improve the temperature rise phenomenon of the coil.

[0067] In one embodiment, the coil parameters include the coil length L, and step S202 may include:

[0068] According to the formula for coil length L= Using W and a preset coefficient K, the length of the first coil 100 is obtained. = W*K, and the length of the second coil 200 = W*(1 / K), Here, W represents the average turn length of the coil, and W represents the total number of turns of the coil. and satisfy: / = .

[0069] It should be noted that, in this embodiment of the invention, the length of the coil can refer to the length of the wire used to make the coil, according to the coil length formula: L = W and a preset coefficient K, where... Let W be the average turn length of the coil, in meters (m); and let W be the total number of turns. The lengths of the first coil (100) and the second coil (200) can then be calculated.

[0070] The length of the first coil 100: = W*K(7);

[0071] The length of the second coil 200: = W*(1 / K) (8);

[0072] According to equations (7) and (8), we can obtain: / =( W*K) / W*(1 / K)= (9).

[0073] The present invention can calculate the length ratio of the first coil 100 and the second coil 200 through the above calculation process, and use it as the reference parameter for the design scheme of the two. In one example, the designer can select the size of the preset coefficient K according to the capacity of the transformer, such as K=0.85. According to the calculated formula (9), the length of the first coil 100 is about 0.723 times the length of the second coil 200. Based on this, the designer can design the coil according to this length ratio. Specifically, the first coil 100 can be designed according to the design parameters of the standard coil, while the design parameters of the second coil 200 are calculated according to this length ratio and the design parameters of the first coil 100. The design of the second coil 200 can then be achieved by increasing the length of the second coil 200 immersed in the upper layer of oil, thereby increasing its heat dissipation area and improving the heat dissipation performance of the second coil 200, so that the temperature spread is more uniform during the operation of the coil and the temperature rise phenomenon of the coil is improved.

[0074] In one embodiment, the coil parameters include the coil weight G, and step S202 may include:

[0075] According to the coil weight formula G=3LAg, the weight of the first coil 100 is obtained. =3 g, and the weight of the second coil 200. =3 g, where g is the material density of the coil;

[0076] Based on the weight of the first coil 100 =3 g, weight of the second coil 200 =3 g、 / = as well as / = ,get and satisfy: / = .

[0077] It should be noted that, in this embodiment of the invention, the coil weight can be the weight of the wire used to make the coil, calculated according to the coil weight formula G=3LAg, where G is the coil weight in kg; L is the total length of the coil in m; and A is the total cross-sectional area of ​​the wire in mm. g represents the material density of the coil; for copper wire, it is 8.9 g / L. The weights of the first coil 100 and the second coil 200 can be obtained respectively:

[0078] The weight of the first coil (100): =3 g (10);

[0079] The weight of the second coil 200: =3 g (11);

[0080] According to equations (6), (9), (10) and (11) and the preset coefficient K, we can obtain: / = (12).

[0081] The embodiments of the present invention can calculate the weight ratio of the first coil 100 and the second coil 200 through the above calculation process, and use this as the benchmark parameter for their design schemes. In one example, the designer can select a preset coefficient K according to the transformer capacity, such as K=0.85. According to the calculated formula (12), the weight of the first coil 100 is about 0.52 times the weight of the second coil 200. Based on this, the designer can design the coil according to this weight ratio. Specifically, the first coil 100 can be designed according to the design parameters of the standard coil, while the design parameters of the second coil 200 are calculated according to this weight ratio and the design parameters of the first coil 100. The design of the second coil 200 can then be achieved by increasing the heat dissipation performance of the second coil 200 immersed in the upper layer of oil, so that the temperature spread is more uniform during the operation of the coil and the temperature rise phenomenon of the coil is improved.

[0082] In one embodiment, the coil parameters include the coil's load loss. Step S202 may include:

[0083] According to the formula for calculating the resistance of a coil, R=ρ(L / A), the resistance of the first coil (100Ω) is obtained. =ρ( ), and the resistance of the second coil 200. =ρ( );

[0084] According to the coil resistance loss formula = =3 R and a preset coefficient K are used to obtain the load loss of the first coil 100. =3 *(1 / K), and the load loss of the second coil 200. =3 *K;

[0085] Based on the load loss of the first coil 100 =3 * (1 / K), Load loss of the second coil 200 =3 *K, Resistance of the first coil (100Ω) =ρ( The resistance of the second coil 200 =ρ( ),get / =( / () / )* ;

[0086] according to / =( / () / )* , / = as well as / = ,get and satisfy: / = .

[0087] It should be noted that, in this embodiment of the invention, the coil is folded to 75 degrees. Load loss at time C For coil resistance loss The sum of eddy current and circulating losses. If eddy current and circulating losses are neglected, then... = Based on this, in embodiments of the present invention, it is possible to... Considered as Equal. In this embodiment, the resistance of the coil can be that of the wire used to make the coil at 75°. The DC resistance at time C is calculated using the formula R = ρ (L / A) for the coil resistance, where ρ is the coil's resistance at 75°. The resistivity at temperature C is expressed in Ω. / m, the resistance of the first coil 100 and the second coil 200 can be obtained respectively:

[0088] The resistance of the first coil is 100. =ρ( (13);

[0089] The resistance of the second coil is 200. =ρ( (14);

[0090] According to the coil resistance loss formula = =3 R and the preset coefficient K can be used to calculate the load losses of the first coil 100 and the second coil 200 respectively:

[0091] Load loss of the first coil 100: =3 *(1 / K) (15;

[0092] Load loss of the second coil 200: =3 *K (16);

[0093] According to equations (13), (14), (15), and (16), we can obtain: / =( / () / )* (17);

[0094] According to equations (6), (9) and (17), we can obtain: / = (18).

[0095] The embodiments of the present invention can calculate the load loss ratio of the first coil 100 and the second coil 200 through the above calculation process, and use it as the benchmark parameter for the design scheme of the two. In one example, the designer can select the size of the preset coefficient K according to the capacity of the transformer, such as K=0.85. According to the calculated formula (18), the load loss of the first coil 100 is about 1.384 times that of the load loss of the second coil 200. Based on this, the designer can design the coil according to this load loss ratio. Specifically, the first coil 100 can be designed according to the design parameters of the standard coil, while the design parameters of the second coil 200 are calculated according to this load loss ratio and the design parameters of the first coil 100. Then, the design parameters of the second coil 200 are designed, which can increase the heat dissipation performance of the second coil 200 immersed in the upper oil layer, so that the temperature spread is more uniform during the operation of the coil and the temperature rise phenomenon of the coil is improved.

[0096] In one embodiment, the coil parameters include the coil's thermal load Q, and step S202 may include:

[0097] According to the coil's heat load formula Q=1.032 / S, to obtain the heat load of the first coil 100. =1.032 / S*(1 / K), and the heat load of the second coil 200. =1.032 / S*K, where S is the effective heat dissipation area of ​​the coil;

[0098] According to the heat load of the first coil 100 =1.032 / S*(1 / K), the heat load of the second coil 200 =1.032 / S*K and / = ,get and satisfy: / = .

[0099] It should be noted that, according to the coil's heat load formula Q=1.032 / S, where Q is the unit heat load on the coil surface, in W / , The coil being calculated is folded to 75. The load loss at time C is expressed in W; S is the effective heat dissipation area of ​​the coil being calculated, expressed in m². The heat loads of the first coil 100 and the second coil 200 can be obtained respectively.

[0100] The heat load of the first coil 100: =1.032 / S*(1 / K) (19;

[0101] The heat load of the second coil 200: =1.032 / S*K (20);

[0102] According to equations (18), (19) and (20), we can obtain: / = (twenty one).

[0103] The embodiments of the present invention can calculate the heat load ratio between the first coil 100 and the second coil 200 through the above calculation process, and use this as the benchmark parameter for their design schemes. In one example, the designer can select the size of a preset coefficient K according to the transformer capacity, such as K=0.85. According to the calculated formula (21), the heat load of the first coil 100 is about 1.91 times that of the second coil 200. Furthermore, since the coil temperature rise calculation formula is related to the heat load of the coil and is directly proportional to it, according to the coil temperature rise formula: =k It can be seen that since k and n in the formula are generally approximate values ​​obtained from experimental results, k and n in the coil temperature rise formula are known constants. Therefore, the ratio of the temperature rise of the first coil 100 and the second coil 200 is approximately the ratio of the heat load of the first coil 100 and the second coil 200. Based on this, designers can design coils according to this heat load ratio. Specifically, the first coil 100 can be designed according to the design parameters of a standard coil, while the design parameters of the second coil 200 are calculated according to this heat load ratio and the design parameters of the first coil 100. By designing the second coil 200, the heat dissipation performance of the second coil 200 immersed in the upper oil layer can be increased, making the temperature spread more uniform during coil operation and improving the temperature rise phenomenon of the coil.

[0104] In summary, the embodiments of the present invention can design coils that can improve the heating phenomenon by calculating and comparing data such as current density, cross-sectional area, length, weight, and load heat load of the first coil 100 and the second coil 200.

[0105] Reference Figure 3The diagram shows a schematic representation of a coil embodiment of the present invention for use in a transformer. The coil includes a first coil 100 and a second coil 200. The second coil 200 is disposed above the first coil 100 along the height direction of the transformer. The first coil 100 is made of a first conductor 110, and the second coil is made of a second conductor 210. The width of the second conductor 210 is greater than the width of the first conductor 110, and / or the thickness of the second conductor 210 is greater than the thickness of the first conductor 110.

[0106] In this embodiment of the invention, a second coil 200 located at a higher oil temperature is formed by using a second wire 210 with a larger width and / or thickness compared to the first wire 110. This increases the heat dissipation area of ​​the second coil 200 and reduces the current density, effectively lowering the temperature at that location. This reduces temperature unevenness in the coil, improves the overall temperature rise of the coil, increases material utilization, reduces costs, improves the operating quality of the transformer, and extends its service life. (Refer to...) Figure 4 and Figure 5 Two embodiments of the coil structure of the present invention are shown. Figure 4 It is a coil with a layered structure. Figure 5 The coil is a disc-shaped structure. The structure of the coil can be selected by those skilled in the art according to the actual situation, and this embodiment does not limit it.

[0107] In one embodiment of the present invention, a transformer is also disclosed, including the coil disclosed in the above embodiments that can improve the temperature rise phenomenon.

[0108] It should be noted that, for the sake of simplicity, the method embodiments are all described as a series of actions. However, those skilled in the art should understand that the embodiments of the present invention are not limited to the described order of actions, because according to the embodiments of the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions involved are not necessarily essential to the embodiments of the present invention.

[0109] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0110] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present invention.

[0111] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0112] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A coil design method, applied to the manufacture of transformer coils, characterized in that, include: The coil is divided into at least a first coil and a second coil; Along the height direction of the transformer, the second coil is positioned above the first coil. The second coil is immersed in the upper layer of oil. The oil temperature in the upper layer of the tank is higher than that in the lower layer. The first coil is made of a first wire, and the second coil is made of a second wire. The width of the second wire is greater than the width of the first wire, and / or the thickness of the second wire is greater than the thickness of the first wire, so as to increase the heat dissipation area on the surface of the second coil and reduce the current density inside the second coil. The coil parameters of the first coil and the second coil are calculated according to a preset coefficient K, where K is selected based on the transformer capacity and K=0.

85. The coil parameters include the current density J of the coil. The calculation of the coil parameters of the first coil and the second coil according to the preset coefficient K includes: The current density of the first coil is obtained based on the current density formula J=I / A of the coil and the preset coefficient K. =(I / A)*1 / K, and the current density of the second coil. =(I / A)*K, where I is the phase current data of the coil, and A is the total cross-sectional area of ​​the coil. and stated satisfy: / = ; The coil parameters include the cross-sectional area A of the coil. The calculation of the coil parameters of the first coil and the second coil according to a preset coefficient K further includes: The cross-sectional area of ​​the first coil is obtained according to the formula A=I / J for the cross-sectional area of ​​the coil and the preset coefficient K. =I / and the cross-sectional area of ​​the second coil =I / ; Based on the cross-sectional area of ​​the first coil =I / The cross-sectional area of ​​the second coil =I / and the / = , to obtain the and stated satisfy: / = ; The coil parameters include the length L of the coil, and the calculation of the coil parameters of the first coil and the second coil according to a preset coefficient K includes: According to the coil length formula L= The length of the first coil is obtained by using W and the preset coefficient K. = W*K, and the length of the second coil = W*(1 / K), the The average turn length of the coil is given by W, and the total number of turns of the coil is given by W. and stated satisfy: / = ; The coil parameters include the weight G of the coil, and the calculation of the coil parameters of the first coil and the second coil according to a preset coefficient K further includes: The weight of the first coil is obtained using the coil weight formula G=3LAg. =3 g, and the weight of the second coil =3 g, where g is the material density of the coil; Based on the weight of the first coil =3 g. Weight of the second coil =3 g. The above / = and the / = , to obtain the and stated satisfy: / = ; The coil parameters include the coil's load loss. The step of calculating the coil parameters of the first coil and the second coil according to the preset coefficient K further includes: The resistance of the first coil is obtained according to the formula R=ρ(L / A). =ρ( ), and the resistance of the second coil. =ρ( ); According to the formula for the resistance loss of the coil = =3 The load loss of the first coil is obtained by using R and the preset coefficient K. =3 *(1 / K), and the load loss of the second coil. =3 *K; Based on the load loss of the first coil =3 * (1 / K), Load loss of the second coil =3 *K, Resistance of the first coil =ρ( The resistance of the second coil =ρ( ),get / =( / () / )* ; According to the above / =( / () / )* The above / = and the / = , to obtain the and stated satisfy: / = ; The coil parameters include the coil's heat load Q. The calculation of the coil parameters for the first and second coils based on a preset coefficient K further includes: According to the heat load formula of the coil, Q=1.032 / S, to obtain the heat load of the first coil =1.032 / S*(1 / K), and the thermal load of the second coil =1.032 / S*K, where S is the effective heat dissipation area of ​​the coil; According to the heat load of the first coil =1.032 / S*(1 / K), the heat load of the second coil =1.032 / S*K and / = , to obtain the and satisfy: / = ; Based on the heat load and The ratio controls the temperature rise of the first and second coils.

2. A coil for use in a transformer, characterized in that, The coil is manufactured using the coil design method as described in claim 1. The coil includes a first coil and a second coil, the second coil being disposed above the first coil along the height direction of the transformer. The first coil is made of a first wire, the second coil is made of a second wire, the width of the second wire is greater than the width of the first wire, and / or the thickness of the second wire is greater than the thickness of the first wire.

3. A transformer, characterized in that, Includes the coil as described in claim 2.

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