Three-frame combined triple frequency transformer

Abstract

The present application relates to a three-part frame combined triple frequency transformer, comprising three sub-frame cores, three primary windings and three secondary windings, the three primary windings are respectively wound on adjacent core columns of the three sub-frame cores, the three secondary windings are respectively wound on the same side cross yoke of the three sub-frame cores, the three primary windings are connected to the three-phase end, the three secondary windings are connected and then connected to the single-phase end, the voltage frequency of the single-phase end is three times the voltage frequency of the three-phase end, which avoids the sub-frame cores working in a highly saturated state, and there is no need to limit the connection method of the primary winding, thereby realizing the triple frequency voltage output of the secondary winding, with small excitation current and higher efficiency.

Description

Technical Field

[0001] The present application relates to the technical field of transformers, and in particular to a three-frame combined triple frequency transformer. Background Art

[0002] The triple frequency transformer uses the nonlinear and saturation characteristics of ferromagnetic materials and the special connection of windings to generate rich third harmonics in the transformer, and uses the third harmonics to form a triple frequency voltage. Ferromagnetic triple frequency transformers have been widely used in the testing of transformers and voltage transformers and other equipment, and in frequency-divided power transmission systems.

[0003] In the prior art, in order to realize a triple frequency transformer, most of them use three single-phase transformers with equal magnetic path lengths. The primary winding is star-connected, the secondary winding is open triangle-connected, and the core operates in a highly saturated state, resulting in problems such as large excitation current and low efficiency. Summary of the invention

[0004] Based on this, it is necessary to provide a three-frame combined triple frequency transformer to address the problems of large excitation current and low efficiency of the existing triple frequency transformer.

[0005] A three-part frame combined triple frequency transformer, comprising: an iron core and a winding, wherein the iron core comprises a first part-frame iron core, a second part-frame iron core and a third part-frame iron core, wherein the first part-frame iron core and the second part-frame iron core are adjacent to each other and are combined into a first core column, the second part-frame iron core and the third part-frame iron core are adjacent to each other and are combined into a second core column, and the third part-frame iron core and the first part-frame iron core are adjacent to each other and are combined into a third core column;

[0006] The winding includes three primary windings and three secondary windings, the three primary windings are respectively wound on the first core column, the second core column and the third core column, the three secondary windings are respectively wound on the cross yoke on the same side of the first sub-frame iron core, the second sub-frame iron core and the third sub-frame iron core, the three primary windings are connected to the three-phase end after being connected, and the three secondary windings are connected to the single-phase end after being connected, and the voltage frequency of the single-phase end is three times the voltage frequency of the three-phase end.

[0007] In one embodiment, the first sub-frame core, the second sub-frame core and the third sub-frame core are all rectangular sub-frame cores and are arranged in an equilateral triangle.

[0008] In one embodiment, the areas of the first frame core, the second frame core and the third frame core are equal.

[0009] In one embodiment, adjacent core columns of the first sub-frame core, the second sub-frame core and the third sub-frame core are separated by equidistant air gaps.

[0010] In one embodiment, the first frame core, the second frame core and the third frame core are wound cores or laminated cores.

[0011] In one embodiment, the three primary windings are connected in a Y connection, a D connection or a YN connection.

[0012] In one embodiment, the three primary windings are wound in the same direction on the core.

[0013] In one embodiment, the three secondary windings are connected in an open triangle manner.

[0014] In one embodiment, the three secondary windings are wound in the same direction on the core.

[0015] In one of the embodiments, it further includes three voltage regulating windings, which are wound on the transverse yoke of the split frame core opposite to the secondary windings.

[0016] The above-mentioned three-part frame combined triple frequency transformer has an iron core consisting of three sub-frame iron cores, three primary windings are wound on the core columns adjacent to each sub-frame iron core, three secondary windings are wound on the cross yoke on the same side of each sub-frame iron core, the three primary windings are connected to the three-phase terminal after being connected, and the three secondary windings are connected to the single-phase terminal after being connected. There is no need to limit the connection method of the primary winding, which avoids each sub-frame iron core working in a highly saturated state, realizes the triple frequency voltage output of the secondary winding, and has a small excitation current and higher efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural diagram of a three-frame combined triple frequency transformer in one embodiment;

[0018] Figure 2 is a wiring diagram of three primary windings in one embodiment;

[0019] Figure 3 is a wiring diagram of three primary windings in another embodiment;

[0020] Figure 4 is a wiring diagram of three primary windings in another embodiment;

[0021] Figure 5 FIG. 4 is a connection diagram of three secondary windings in one embodiment.

[0022] Description of the drawings: 11. First sub-frame core; 12. Second sub-frame core; 13. Third sub-frame core; 21. A-phase primary winding; 22. B-phase secondary winding; 23. C-phase primary winding; 31. A-phase secondary winding; 32. B-phase secondary winding; 33. C-phase secondary winding. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0025] It is understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0026] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0027] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" etc. specify the presence of stated features, wholes, steps, operations, components, parts or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof.

[0028] In one embodiment, Figure 1As shown in the figure, a three-part frame combined triple-frequency transformer is provided, including: an iron core and windings. The iron core includes a first sub-frame iron core 11, a second sub-frame iron core 12, and a third sub-frame iron core 13. The adjacent parts of the first sub-frame iron core 11 and the second sub-frame iron core 12 are combined into a first core column, the adjacent parts of the second sub-frame iron core 12 and the third sub-frame iron core 13 are combined into a second core column, and the adjacent parts of the third sub-frame iron core 13 and the first sub-frame iron core 11 are combined into a third core column. The windings include three primary windings (21, 22, 23) and three secondary windings (31, 32, 33). The three primary windings (21, 22, 23) are respectively wound around the first core column, the second core column, and the third core column. The three secondary windings (31, 32, 33) are respectively wound on the same-side yokes of the first sub-frame iron core, the second sub-frame iron core, and the third sub-frame iron core. After the three primary windings (21, 22, 23) are connected, they are connected to the three-phase terminal. After the three secondary windings (31, 32, 33) are connected, they are connected to the single-phase terminal. The voltage frequency of the single-phase terminal is three times the voltage frequency of the three-phase terminal.

[0029] Specifically, the first sub-frame iron core 11, the second sub-frame iron core 12, and the third sub-frame iron core 13 are three quadrilateral sub-frame iron cores, each including upper and lower yokes and left and right columns. Optionally, each pair of sub-frame iron cores is combined together through the column sides and arranged in a triangular structure, or each pair of sub-frame iron cores is combined together through the yoke sides and arranged in a triangular structure. In this embodiment, taking the combination of each pair of sub-frame iron cores through the column sides as an example, the left column of the first sub-frame iron core 11 and the right column of the second sub-frame iron core 12 are combined into the first core column, the left column of the second sub-frame iron core 12 and the right column of the third sub-frame iron core 13 are combined into the second core column, and the left column of the third sub-frame iron core 13 and the right column of the first sub-frame iron core 11 are combined into the third core column. Among them, the sizes of each sub-frame iron core need to be kept consistent, including the width and cross-sectional area of the yoke being the same, and the length and cross-sectional area of the column being the same. Optionally, the width of the yoke of each sub-frame iron core can be equal to the length of the column of each sub-frame iron core, the width of the yoke of each sub-frame iron core can also be less than the length of the column of each sub-frame iron core, and the width of the yoke of each sub-frame iron core can also be greater than the length of the column of each sub-frame iron core, which is not limited thereto.

[0030] Further, the winding includes three primary windings connected to the three-phase end, and three secondary windings connected to the single-phase end, wherein the three-phase end connected to the three primary windings can be used as either a power input end or a power output end, and correspondingly, the single-phase end connected to the three secondary windings can also be used as either a power input end or a power output end. It can be understood that when the turn ratio of the three primary windings to the three secondary windings is fixed, the triple frequency transformer of the present application can be used as a step-down transformer or as a step-up transformer. Specifically, the three primary windings include an A-phase primary winding 21, a B-phase primary winding 22, and a C-phase primary winding 23, and the three secondary windings include an a-phase secondary winding 31, a b-phase secondary winding 32, and a c-phase secondary winding 33.

[0031] Among them, the three primary windings are respectively wound on the first core column, the second core column and the third core column, the A-phase primary winding 21 is wound on the first core column, the B-phase primary winding 22 is wound on the second core column, and the C-phase primary winding 23 is wound on the third core column. The A-phase primary winding 21, the B-phase primary winding 22 and the C-phase primary winding 23 have the same winding direction and are connected to the three-phase end with the same polarity. For example, assuming that the positive direction of the magnetic flux in each core column wound by each primary winding is from bottom to top, the positive direction of the magnetic flux flowing through each sub-frame iron core is counterclockwise. It can be understood that since the three input phases of the three-phase power supply differ by 120°, the three-phase fundamental waves in each sub-frame iron core can be offset. In addition, the A-phase primary winding 21, the B-phase primary winding 22 and the C-phase primary winding 23 are wound with the same number of turns and the materials used are also the same. Optionally, the material can be electromagnetic wire, copper foil, etc., without limitation.

[0032] In addition, the three secondary windings are respectively wound on the same side transverse yoke of the first sub-frame core 11, the second sub-frame core 12 and the third sub-frame core 13, and can be respectively wound on the upper transverse yoke of each sub-frame core, or respectively wound on the lower transverse yoke of each sub-frame core. In this embodiment, the three secondary windings are respectively wound on the upper transverse yoke of the first sub-frame core 11, the second sub-frame core 12 and the third sub-frame core 13 as an example for explanation, the a-phase secondary winding 31 is wound on the upper transverse yoke of the first sub-frame core 11, the b-phase secondary winding 32 is wound on the upper transverse yoke of the second sub-frame core 12, and the c-phase secondary winding 33 is wound on the upper transverse yoke of the third sub-frame core 13. Similarly, the a-phase secondary winding 31, the b-phase secondary winding 32 and the c-phase secondary winding 33 also have the same winding direction, and can be connected in series with the same polarity and then connected to the single-phase end. At this time, due to the cancellation of the three-phase fundamental waves in each sub-frame core, the voltage frequency at the single-phase end is three times the voltage frequency at the three-phase end, that is, the voltage frequency of the secondary winding is three times the voltage frequency of the primary winding. In addition, the number of turns of the a-phase secondary winding 31, the b-phase secondary winding 32, and the c-phase secondary winding 33 are the same, and the materials used are also the same. Optionally, the material can be electromagnetic wire, copper foil, etc., without limitation.

[0033] The following Figure 1 The working principle of the three-frame combined triple frequency transformer is explained by taking the structure diagram of the three-frame combined triple frequency transformer as an example. Assuming that the magnetic flux passing through the A-phase primary winding 21, the B-phase primary winding 22 and the C-phase primary winding 23 can be understood as the synthetic magnetic flux passing through the two adjacent frame cores, which are φ A (t),φ B (t) and φ C (t), which is assumed to be as follows based on the winding direction and the direction of the magnetic flux generated by the current Figure 2 The magnetic flux passing through the a-phase secondary winding 31, the b-phase secondary winding 32 and the c-phase secondary winding 33 can be understood as the magnetic flux passing through each frame core, which is φ a (t),φ b (t) and φ c (t), which is assumed to be as follows based on the winding direction and the direction of the magnetic flux generated by the current Figure 2 As shown in the marked direction, according to Kirchhoff's law of magnetic circuit, we can get:

[0034]

[0035] Due to the nonlinear characteristics of the ferromagnetic material used in each sub-frame core, the magnetic flux φ passing through each sub-frame core a (t),φ b (t) and φ cIn (t), in addition to the fundamental wave component, there are also zero-sequence odd harmonics such as 3, 9, 15, etc., and the third harmonic is the main one, and other high-order harmonics can be ignored. Then, assuming that the magnetic flux φ passing through the core of each frame is a (t),φ b (t) and φ c (t) are:

[0036] φ a (t) = φ m sin(ωt)+kφ m sin(3ωt+θ) (2)

[0037]

[0038]

[0039] Among them, φ m is the magnetic flux φ passing through each frame core a (t),φ b (t) and φ c (t) is the amplitude of the fundamental magnetic flux, ω is the angular frequency, θ is the initial phase angle; in addition, k is the magnetic flux φ passing through the core of each frame a (t),φ b (t) and φ c (t) The content ratio of the third harmonic.

[0040] Then, since the three secondary windings are connected in an open triangle, the induced voltage u at both ends is 2 is equal to the derivative of the sum of the fluxes passing through the a-phase secondary winding 31, the b-phase secondary winding 32 and the c-phase secondary winding 33, that is, according to equations (2), (3) and (4), we can obtain:

[0041]

[0042] Where n 2 is the number of turns of the a-phase secondary winding 31 , the b-phase secondary winding 32 , and the c-phase secondary winding 33 .

[0043] Then, since the fundamental waves of the three phases in the iron cores of each subframe can cancel each other, we can get:

[0044] u 2 =3kφ m n 2 sin(3ωt+θ) / dt (6)

[0045] By taking the derivative of formula (6), we can get:

[0046] u 2 =9kφ m n 2cos(3ωt+θ) (7)

[0047] From formula (7), we can know that the induced voltage u across the three secondary windings is 2 The frequency is three times the frequency of the voltage across the primary winding, realizing a triple frequency transformer.

[0048] The above-mentioned three-part frame combined triple frequency transformer has an iron core consisting of three sub-frame iron cores, three primary windings are wound on the core columns adjacent to each sub-frame iron core, and three secondary windings are wound on the cross yoke on the same side of each sub-frame iron core. The three primary windings are connected to the three-phase terminal after being connected, and the three secondary windings are connected to the single-phase terminal after being connected. There is no need to limit the connection method of the primary winding, which avoids the sub-frame iron cores working in a highly saturated state, realizes the triple frequency voltage output of the secondary winding, and has a small excitation current and higher efficiency.

[0049] In one embodiment, Figure 1 As shown, the first sub-frame core 11, the second sub-frame core 12 and the third sub-frame core 13 are all rectangular sub-frame cores, and are arranged in an equilateral triangle. Specifically, the width of the transverse yoke of the first sub-frame core 11, the second sub-frame core 12 and the third sub-frame core 13 is greater than the length of its column, and the angles between the transverse yoke of the first sub-frame core 11, the second sub-frame core 12 and the third sub-frame core 13 and its column are all right angles, that is, the first sub-frame core 11, the second sub-frame core 12 and the third sub-frame core 13 are all rectangular sub-frame cores. Each rectangular sub-frame core is spliced ​​into an equilateral triangle structure through its column edges.

[0050] In one embodiment, Figure 1 As shown, the areas of the first sub-frame core 11, the second sub-frame core 12 and the third sub-frame core 13 are equal. Specifically, since the widths of the upper and lower transverse yokes of the first sub-frame core 11, the second sub-frame core 12 and the third sub-frame core 13 are equal, and the lengths of the left and right columns of the first sub-frame core 11, the second sub-frame core 12 and the third sub-frame core 13 are also equal, the areas enclosed by the upper and lower transverse yokes and the left and right columns of the first sub-frame core 11, the second sub-frame core 12 and the third sub-frame core 13 are equal.

[0051] In this embodiment, each frame core can not continuously work in a high saturation state during operation, thereby improving the efficiency of the triple frequency transformer. Figure 1As shown, the first sub-frame core 11, the second sub-frame core 12 and the third sub-frame core 13 are wound cores or stacked cores. Specifically, each sub-frame core can be formed by rolling a core strip by a core winding machine and then annealing it, or it can be formed by stacking a plurality of core sheets, and then the core sheets are seamlessly joined together by a clamping device. Among them, different materials can be selected for the core strip and the core sheets, which can be magnetic materials such as ferrite, amorphous alloy, ultra-thin silicon steel or nanocrystalline. In this embodiment, the sub-frame core made of nonlinear ferromagnetic material can generate rich zero-sequence harmonic flux between the sub-frames.

[0052] In one embodiment, Figure 1 As shown, adjacent core columns of the first sub-frame core 11, the second sub-frame core 12 and the third sub-frame core 13 are separated by equidistant air gaps.

[0053] Specifically, the left column of the first sub-frame core 11 and the right column of the second sub-frame core 12, the left column of the second sub-frame core 12 and the right column of the third sub-frame core 13, and the left column of the third sub-frame core 13 and the right column of the first sub-frame core 11 are separated by equidistant air gaps, that is, it can be understood that the first core column, the second core column and the third core column all have equidistant air gaps. Since the magnetic resistance of the air gap is much greater than the magnetic resistance of the core sheet, when the air gap is greater than 2mm, it can be considered that the magnetic circuit between adjacent sub-frame cores is in an open circuit state, so the air gap size between the adjacent core columns of the first sub-frame core 11, the second sub-frame core 12 and the third sub-frame core 13 is greater than 2mm, for example, the air gap size can be 6mm. In this embodiment, the core columns of each sub-frame core are separated by equidistant air gaps, and the magnetic flux of each sub-frame core is independent of each other under the premise of maintaining the symmetry of the magnetic circuit of each sub-frame core.

[0054] In one embodiment, Figure 2 , Figure 3 as well as Figure 4 As shown, the connection mode of the three primary windings (21, 22, 23) is Y connection, D connection or YN connection.

[0055] Specifically, the connection form of the three primary windings is not unique, and can be Y connection, D connection, or YN connection. Among the three connection modes, the head ends of the A-phase primary winding 21, the B-phase primary winding 22, and the C-phase primary winding 23 are all used to connect to the three-phase power grid terminal.

[0056] Furthermore, if Figure 2 As shown, the three primary windings are connected in a Y-type manner, and the tail ends of the A-phase primary winding 21, the B-phase primary winding 22, and the C-phase primary winding 23 are connected at one point. Figure 3As shown, the three primary windings are connected in a D-type manner, where the A-phase primary winding 21, the B-phase primary winding 22, and the C-phase primary winding 23 are connected end to end, with the beginning of the A-phase primary winding 21 connected to the end of the B-phase primary winding 22, the beginning of the B-phase primary winding 22 connected to the end of the C-phase primary winding 23, and the beginning of the C-phase primary winding 23 connected to the end of the A-phase primary winding 21. Figure 4 As shown, the three primary windings are connected in a YN type, and the tail ends of the A-phase primary winding 21, the B-phase primary winding 22, and the C-phase primary winding 23 are connected at one point and grounded through the point.

[0057] In this embodiment, there is no need to limit the connection mode of the primary winding, thereby solving the problem of single connection mode of the primary winding of the existing ferromagnetic triple frequency transformer.

[0058] In one embodiment, Figure 2 , Figure 3 as well as Figure 4 As shown, the three primary windings (21, 22, 23) are wound on the core in the same direction.

[0059] Specifically, when power is applied, the phase difference between the electromotive force phasors of the winding coils is generated, thereby generating magnetic flux on the core. Therefore, the A-phase primary winding 21, the B-phase primary winding 22, and the C-phase primary winding 23 are wound on the core in the same winding direction, and as shown in FIG. Figure 2 , Figure 3 as well as Figure 4 The three-phase power is input from the head end of the A-phase primary winding 21, the B-phase primary winding 22 and the C-phase primary winding 23, that is, the head end of the A-phase primary winding 21, the B-phase primary winding 22 and the C-phase primary winding 23 are all the end points with positive electromotive force, that is, the same-name end. In this embodiment, by setting the same winding direction and the same-name end, and the phase difference of the three-phase power supply is 120°, the three-phase fundamental waves in the iron core of each sub-frame can be offset.

[0060] In one embodiment, Figure 5 As shown, the connection mode of the three secondary windings (31, 32, 33) is an open triangle connection. Specifically, the output ends of the three secondary windings serve as single-phase ends, the head end of the a-phase secondary winding 31 serves as one end of the single-phase end, the tail end of the a-phase secondary winding 31 is connected to the head end of the b-phase secondary winding 32, the tail end of the b-phase secondary winding 32 is connected to the head end of the c-phase secondary winding 33, and the tail end of the c-phase secondary winding 33 serves as the other end of the single-phase end.

[0061] In one embodiment, Figure 5As shown, the three secondary windings (31, 32, 33) are wound in the same direction on the iron core. Specifically, the a-phase secondary winding 31, the b-phase secondary winding 32, and the c-phase secondary winding 33 are wound on the split frame iron core in the same winding direction, and as shown in FIG. Figure 5 The middle dots are marked as the positive end points of the electromotive force of the a-phase secondary winding 31, the b-phase secondary winding 32 and the c-phase secondary winding 33, i.e., the same-named ends. In this embodiment, by setting the same winding direction and the same-named ends, and the three-phase power supply phase difference of 120°, the three-phase fundamental waves in the iron cores of each sub-frame can be offset.

[0062] In one embodiment, the above three-frame combined triple frequency transformer further includes three voltage regulating windings, which are respectively connected to three secondary windings, and the three voltage regulating windings are wound on the transverse yoke of the split frame core.

[0063] Specifically, the three voltage regulating windings are respectively connected in series with a secondary winding, thereby changing the number of turns of the secondary winding of the triple frequency transformer. When the voltage regulating winding and the secondary winding are wound with the same polarity and direction, the number of turns of the secondary winding can be increased, and when the voltage regulating winding and the secondary winding are wound in opposite directions, the number of turns of the secondary winding can be reduced.

[0064] Furthermore, the three voltage-regulating windings are wound on the cross yoke of each sub-frame iron core, and the winding method is not unique like the secondary winding. They can be all wound on the upper cross yoke on the same side of each sub-frame iron core, or all wound on the lower cross yoke on the same side of each sub-frame iron core, or they can be respectively wound on the upper cross yoke or the lower cross yoke on different sides of each sub-frame iron core. It can be understood that the voltage-regulating winding can also be laid concentrically on the same cross yoke as the secondary winding, and the concentric laying can be an overlapping arrangement or a left-right arrangement, which is not limited to this.

[0065] In this embodiment, by adding a voltage regulating winding, the magnetic flux in the upper and lower yokes of the triple frequency transformer of the present application is symmetrically increased or decreased, thereby producing an effect of adjustable secondary output voltage.

[0066] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0067] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A three-frame combined triple frequency transformer, It is characterized in that include: The core and the winding, the core comprises a first sub-frame core, a second sub-frame core and a third sub-frame core, the first sub-frame core and the second sub-frame core are adjacently combined into a first core column, the second sub-frame core and the third sub-frame core are adjacently combined into a second core column, and the third sub-frame core and the first sub-frame core are adjacently combined into a third core column; The winding includes three primary windings and three secondary windings, the three primary windings are respectively wound on the first core column, the second core column and the third core column, the three secondary windings are respectively wound on the same side cross yoke of the first sub-frame iron core, the second sub-frame iron core and the third sub-frame iron core, the three primary windings are connected to the three-phase end, the connection method of the three primary windings is Y connection, D connection or YN connection, the three secondary windings are connected to the single-phase end after being connected in an open triangle connection method, and the voltage frequency of the single-phase end is three times the voltage frequency of the three-phase end.

2. The three-frame combined triple frequency transformer according to claim 1, It is characterized in that The first sub-frame core, the second sub-frame core and the third sub-frame core are all rectangular sub-frame cores and are arranged in a triangle.

3. The three-frame combined triple frequency transformer according to claim 2, It is characterized in that The areas of the first sub-frame core, the second sub-frame core and the third sub-frame core are equal.

4. The three-frame combined triple frequency transformer according to claim 3, It is characterized in that The adjacent core columns of the first sub-frame core, the second sub-frame core and the third sub-frame core are separated by equidistant air gaps.

5. The three-frame combined triple frequency transformer according to claim 4, It is characterized in that The air gap between the adjacent core columns of the first sub-frame core, the second sub-frame core and the third sub-frame core is greater than 2 mm.

6. The three-frame combined triple frequency transformer according to claim 4, It is characterized in that The first sub-frame core, the second sub-frame core and the third sub-frame core are wound cores or stacked cores.

7. The three-frame combined triple frequency transformer according to claim 1, It is characterized in that The three primary windings are wound in the same direction on the core.

8. The three-frame combined triple frequency transformer according to claim 1, It is characterized in that The first sub-frame core, the second sub-frame core and the third sub-frame core are made of nonlinear ferromagnetic material.

9. The three-frame combined triple frequency transformer according to claim 8, It is characterized in that The three secondary windings are wound in the same direction on the core.

10. The three-frame combined triple frequency transformer according to any one of claims 1 to 9, It is characterized in that It also includes three voltage regulating windings, which are respectively connected to the three secondary windings, and are wound on the transverse yoke of the split frame core.

Images