Built-in reactor for power transformer and power transformer
By employing an iron yoke structure composed of cylindrical coils and silicon steel blocks in the built-in reactor, combined with the design of cooling oil channels, the overheating problem of the built-in reactor under large magnetic flux is solved, achieving efficient heat dissipation and improved safety.
Patent Information
- Application Number
- CN202422633072.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-29
- Publication Date
- 2025-10-17
- Estimated Expiration
- 2034-10-29
AI Technical Summary
Existing built-in reactors are prone to magnetic concentration, over-vibration, overheating and possible burning under high magnetic flux conditions. Traditional solutions are costly and their effectiveness gradually weakens.
The iron yoke structure consists of multiple cylindrical coils and silicon steel blocks. By setting transition silicon steel blocks in the interphase area and setting cooling oil channels on the insulating plate, the area where magnetic lines of force pass through the silicon steel blocks is reduced, and cooling oil is used for heat dissipation.
It effectively reduces heat generation, improves the heat dissipation efficiency of the built-in reactor, avoids overheating problems, and enhances the safety and reliability of the equipment.
Smart Images
Figure CN223450652U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a kind of built-in reactor for electric power transformer and a kind of electric power transformer. BACKGROUND
[0002] In electrical equipment (for example, electric power transformer), with the increase of capacity and impedance, the magnetic flux of built-in reactor is also more and more big.Current built-in reactor yoke structure under large magnetic flux can produce magnetic density concentration, overvibration, overheat gas production even burn situation.
[0003] When overheat occurs, the traditional solution is to reduce temperature by increasing yoke structure, reducing yoke magnetic density. However, such solution is high in cost, and its effect will gradually weaken with the increase of magnetic flux. SUMMARY
[0004] In order to overcome the above-mentioned defects existing in the prior art, the present disclosure provides a built-in reactor for electric power transformer, the electric power transformer comprising a winding and an oil tank, the built-in reactor being connected to the winding and disposed in the oil tank, the built-in reactor comprising: a plurality of cylindrical coils, each of the cylindrical coils extending along a vertical direction, and the plurality of cylindrical coils being arranged in a row along a first horizontal direction perpendicular to the vertical direction; an upper yoke assembly connected at a top end of the plurality of cylindrical coils; a lower yoke assembly connected at a bottom end of the plurality of cylindrical coils; and a plurality of pull screw groups arranged to fix the upper yoke assembly, the lower yoke assembly and the plurality of cylindrical coils together, each of the upper yoke assembly and the lower yoke assembly comprising a silicon steel block component including two identical silicon steel blocks separated by a middle slit portion extending along the first horizontal direction, the pull screw groups extending through the middle slit portion, the middle slit portion including two end regions at both ends of the middle slit portion and a plurality of pull screw penetration regions and at least one phase interval region arranged alternately between the two end regions, the number of phase interval regions being one less than the number of pull screw penetration regions, and the silicon steel block component further comprising at least one transition silicon steel block, each of the transition silicon steel blocks being disposed at a corresponding phase interval region and clamped between two silicon steel blocks.
[0005] Based on theoretical analysis and simulation, the applicant found that the cause of overheat is that the horizontal component of magnetic flux in the middle slit portion generates a large amount of eddy current loss in the vertical plane of the shield. At the same time, this area lacks sufficient heat dissipation, so overheat points will occur. Accordingly, by the above arrangement, the transition silicon steel blocks occupy the phase interval regions (magnetic lines passing through the silicon steel blocks in the phase interval regions will generate significant heat), which can reduce the area of magnetic lines passing through the silicon steel blocks, thereby reducing the generation of heat.
[0006] Further, the silicon steel block component further comprises two wooden insulation pieces, each of which is arranged at a corresponding end region and clamped between two silicon steel blocks.
[0007] Further, each of the upper and lower yoke assemblies further comprises a housing in which the silicon steel block component is fixed, and an insulation plate arranged between the silicon steel block component and the plurality of cylindrical coils.
[0008] Further, a plurality of cooling oil channels are arranged on a surface of the insulation plate facing the silicon steel block component. Accordingly, heat dissipation of the silicon steel block component can be further enhanced.
[0009] Further, the cooling oil channels extend along a second horizontal direction perpendicular to the first horizontal direction.
[0010] Further, the silicon steel block comprises a plurality of silicon steel layers stacked along the vertical direction. Accordingly, eddy current loss can be reduced, and heat generation can be lowered.
[0011] Further, each of the pull screw assemblies comprises at least one pull screw.
[0012] In addition, the present disclosure also provides an electric power transformer, comprising a winding, an oil tank in which cooling oil is contained, and the aforementioned built-in reactor, which is connected to the winding and arranged in the oil tank and immersed in the cooling oil in the oil tank. BRIEF DESCRIPTION OF DRAWINGS
[0013] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this disclosure, illustrate embodiments of the present disclosure and serve to explain the principles of the present disclosure, and are not intended to limit the present disclosure. In the drawings:
[0014] Figure 1 is a schematic perspective view showing a built-in reactor of the present disclosure;
[0015] Figure 2 is a schematic perspective view showing Figure 1 is a schematic perspective view showing a part of the built-in reactor shown in FIG. 1, in which a part of the upper yoke assembly is removed to show the silicon steel block component;
[0016] Figure 3 is a schematic perspective view showing Figure 2 is a schematic perspective view showing the silicon steel block component shown in FIG. 2;
[0017] Figure 4 is a schematic perspective view showing Figure 1a schematic perspective view of a portion of the built-in reactor shown with a portion of the upper yoke assembly removed to show the insulation board; and
[0018] Figure 5 and Figure 6 are, respectively, a thermal imaging image of a silicon steel block component not according to the present disclosure and a thermal imaging image of a silicon steel block component according to the present disclosure.
[0019] List of Reference Signs
[0020] 100 built-in reactor
[0021] 10 cylindrical coil
[0022] 20 upper yoke assembly
[0023] 30 lower yoke assembly
[0024] 40 draw screw set
[0025] 1 silicon steel block component
[0026] 11 silicon steel block
[0027] 111 silicon steel layer
[0028] 12 transition silicon steel block
[0029] 13 wooden insulation piece
[0030] 14 spacer silicon steel block
[0031] 2 housing
[0032] 3 insulation board
[0033] A center joint portion
[0034] A1 end region
[0035] A2 draw screw penetration region
[0036] A3 interphase region
[0037] C cooling oil channel
[0038] R horizontal rib DETAILED DESCRIPTION
[0039] The technical solutions in the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings in the embodiments of the present disclosure. It should be noted that the embodiments in the present disclosure and the features in the embodiments can be combined with each other without conflict. The pronouns and pronouns in the present patent application are not limited to a specific gender.
[0040] In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments in which the disclosure can be practiced. With regard to the drawings, directional terminology, such as "top," "bottom," "front," "back," "leading," "trailing," etc., is used with reference to the orientation of the Figure(s) being described. Because components of the present disclosure can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments can be utilized and structural or logical changes can be made without departing from the scope of the present disclosure. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present disclosure is defined by the appended claims.
[0041] Reference Figures 1 to 4 The present disclosure proposes an in-built reactor 100 for a power transformer. The power transformer can include a winding and an oil tank, and the in-built reactor is connected to the winding and disposed in the oil tank. The in-built reactor 100 can generally include a plurality of cylindrical coils 10, an upper yoke assembly 20, a lower yoke assembly 30, and a plurality of draw screw sets 40.
[0042] Each cylindrical coil 10 extends along a vertical direction, and the plurality of cylindrical coils 10 are arranged in a row along a first horizontal direction perpendicular to the vertical direction. In particular, a partition can be arranged between adjacent cylindrical coils 10 for shielding.
[0043] The upper yoke assembly 20 is connected at a top end of the plurality of cylindrical coils 10, the lower yoke assembly 30 is connected at a bottom end of the plurality of cylindrical coils 10, and the plurality of draw screw sets 40 are arranged to secure the upper yoke assembly 20, the lower yoke assembly 30, and the plurality of cylindrical coils 10 together, in particular, each draw screw set 40 passes through the upper yoke assembly 20, a corresponding cylindrical coil 10, and the lower yoke assembly 30 to secure them together.
[0044] Each of the upper yoke assembly 20 and the lower yoke assembly 30 can include a silicon steel block component 1. The silicon steel block component 1 associated with the upper yoke assembly 20 is illustrated in the drawings, while the lower yoke assembly 30 has a structure similar to the upper yoke assembly 20 but symmetrically upside down, and thus is not described herein in detail. The silicon steel block component 1 can include two identical silicon steel blocks 11 separated by a mid-slot portion A extending along the first horizontal direction. The draw screw set 40 extends through the mid-slot portion A. The silicon steel block 11 can be laminated by a plurality of silicon steel sheets.
[0045] The mid-slot portion A can include two end regions A1 located at two ends of the mid-slot portion A, and a plurality of draw screw penetration regions A2 and at least one interphase region A3 located between the two end regions A1 and arranged alternately with each other, wherein the number of the interphase region A3 is one less than the number of the draw screw penetration region A2.
[0046] The silicon steel block component 1 can further include at least one transition silicon steel block 12, each of which is disposed at a corresponding inter-phase region A3 and clamped between two silicon steel blocks 11. The transition silicon steel block 12 can be laminated by a plurality of silicon steel sheets. Here, the number of inter-phase regions A3 is the same as the number of transition silicon steel blocks 12, and each of the transition silicon steel blocks 12 is disposed at a corresponding one of the inter-phase regions A3. Since a significant amount of heat is generated when magnetic lines of force pass through the silicon steel blocks at the inter-phase regions, the generation of heat can be effectively reduced by disposing the transition silicon steel blocks 12 at the inter-phase regions A3.
[0047] In addition, the silicon steel block component 1 can further include two wooden insulation pieces 13, each of which is disposed at a corresponding end region A1 and clamped between two silicon steel blocks 11.
[0048] Each of the upper and lower yoke assemblies 20 and 30 can further include a housing 2 and an insulation plate 3. The silicon steel block component 1 is fixed in the housing 2, and the insulation plate 3 is disposed between the silicon steel block component 1 and the plurality of cylindrical coils 10. In particular, for example, for the upper yoke assembly 20, the housing 2 can include a top steel plate and four side steel plates welded to the top steel plate, thereby forming a semi-enclosed structure open on a side opposite to the top steel plate, and the side steel plates on the short side can include two triangular plates, so as to facilitate welding with the silicon steel block component 1 located inside the housing 2. The side opposite to the top steel plate of the housing 2 is open, so that the insulation plate 3 can be adjacent to the silicon steel block component 1.
[0049] In particular, a plurality of cooling oil channels C are provided on the surface of the insulation plate 3 facing the silicon steel block component 1. Since the built-in reactor 100 is operated as a whole immersed in cooling oil, the cooling oil can pass through these cooling oil channels C, so as to facilitate heat dissipation of the silicon steel block component 1.
[0050] The cooling oil channels C can extend along a second horizontal direction perpendicular to the first horizontal direction. In other words, the cooling oil channels C can extend along the direction of the short side, so as to facilitate the passage of the cooling oil. Of course, the present disclosure is not limited thereto, and the cooling oil channels C can also extend along the first horizontal direction.
[0051] In one embodiment, the cooling oil channels C can be formed by a plurality of horizontal ribs R formed on the surface of the insulation plate 3 facing the silicon steel block component 1, that is, the cooling oil channels C are formed between two adjacent horizontal ribs R. In another embodiment, the cooling oil channels C can also be formed by recesses recessed on the surface.
[0052] In addition, the silicon steel block 11 can include a plurality of silicon steel layers 111 stacked along a vertical direction. The silicon steel layers 111 can be laminated by a plurality of silicon steel sheets.
[0053] In addition, each pull screw group 40 includes at least one pull screw. For the case where the pull screw group 40 has a plurality of pull screws, the silicon steel block component 1 can further include at least one spacer silicon steel block 14 located at a corresponding pull screw penetration region and clamped between two silicon steel blocks, for spacing adjacent pull screws. The spacer silicon steel block 14 can be laminated from a plurality of silicon steel sheets.
[0054] Reference is made to Figure 5 and Figure 6 From the heat distribution shown in these thermal images (it should be noted here that Figure 5 and Figure 6 are thermal images rather than photos) obtained by simulation (where the darker the color, the higher the temperature, and the lighter the color, the lower the temperature), compared with Figure 5 the silicon steel block component with the middle joint part filled with wooden insulation shown in Figure 6 the heat generated by the silicon steel block component according to the present disclosure shown in
[0055] In addition, the present disclosure also proposes an electric power transformer, which can include a winding, an oil tank in which cooling oil is contained, and the aforementioned built-in reactor connected to the winding, and the built-in reactor is arranged in the oil tank and immersed in the cooling oil in the oil tank.
[0056] The above description is only the preferred embodiments of the present disclosure and is not intended to limit the present disclosure. For those skilled in the art, the present disclosure can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the protection scope of the present disclosure.
Claims
1. A built-in reactor for a power transformer, the power transformer comprising a winding and an oil tank, the built-in reactor being connected to the winding and disposed in the oil tank, the built-in reactor comprising: a plurality of cylindrical coils (10), each of the cylindrical coils (10) extending in a vertical direction, and the plurality of cylindrical coils (10) being arranged in a row along a first horizontal direction perpendicular to the vertical direction; an upper iron yoke assembly (20), the upper iron yoke assembly (20) being connected to the top ends of the plurality of cylindrical coils (10); a lower iron yoke assembly (30), the lower iron yoke assembly (30) being connected to the bottom ends of the plurality of cylindrical coils (10); as well as a plurality of pull screw rod groups (40), the plurality of pull screw rod groups (40) being arranged to fix the upper iron yoke assembly (20), the lower iron yoke assembly (30) and the plurality of cylindrical coils (10) together; It is characterized by: Each of the upper iron yoke assembly (20) and the lower iron yoke assembly (30) includes a silicon steel block component (1), the silicon steel block component (1) including two identical silicon steel blocks (11) separated by a center seam (A) extending along the first horizontal direction, the pull screw group (40) extending through the center seam (A), The middle seam portion (A) includes two end regions (A1) located at both ends of the middle seam portion (A) and a plurality of pull screw through regions (A2) and at least one interlaced region (A3) located between the two end regions (A1) and arranged alternately with each other, wherein the number of the interlaced regions (A3) is one less than the number of the pull screw through regions (A2), and The silicon steel block component (1) further comprises at least one transition silicon steel block (12), each of the transition silicon steel blocks (12) being arranged at the corresponding interphase region (A3) and being clamped between the two silicon steel blocks (11).
2. The built-in reactor for a power transformer according to claim 1, characterized in that: The silicon steel block component (1) further includes two wooden insulating pieces (13), each of the wooden insulating pieces (13) being arranged at the corresponding end region (A1) and clamped between the two silicon steel blocks (11).
3. The built-in reactor for a power transformer according to claim 1, characterized in that: Each of the upper iron yoke assembly (20) and the lower iron yoke assembly (30) further includes: a housing (2), wherein the silicon steel block component (1) is fixed in the housing (2); and An insulating plate (3) is provided between the silicon steel block component (1) and the plurality of cylindrical coils (10).
4. The built-in reactor for a power transformer according to claim 3, characterized in that: A plurality of cooling oil channels (C) are provided on the surface of the insulating plate (3) facing the silicon steel block component (1).
5. The built-in reactor for a power transformer according to claim 4, characterized in that: The cooling oil channel (C) extends along a second horizontal direction perpendicular to the first horizontal direction.
6. The built-in reactor for a power transformer according to claim 1, characterized in that: The silicon steel block (11) comprises a plurality of silicon steel layers (111) stacked along the vertical direction.
7. The built-in reactor for a power transformer according to claim 1, characterized in that: Each of the pull screw groups (40) includes at least one pull screw.
8. A power transformer, characterized in that: The power transformer comprises: winding; an oil tank containing cooling oil; and The built-in reactor according to any one of claims 1 to 7, wherein the built-in reactor is connected to the winding, and the built-in reactor is provided in the oil tank and immersed in cooling oil in the oil tank.