Coil oil duct partition plate structure and oil-immersed transformer

Abstract

The coil oil duct partition plate structure comprises a plurality of layers of insulating cylinders which are sequentially distributed from inside to outside, a plurality of oil duct supporting strips are arranged on the outer walls of the insulating cylinders, a plurality of oil duct partition plates are arranged on the oil duct supporting strips, and a plurality of oil duct partition plates are arranged on the oil duct supporting strips. According to the structure and the transformer, the oil flow, the mechanical strength and the insulating strength can be balanced at the same time.

Description

Technical Field

[0001] This invention belongs to the field of transformer technology and relates to a coil oil passage partition structure and an oil-immersed transformer. Background Technology

[0002] Oil-immersed transformers typically have multiple layers of insulating sleeves arranged in the channels between the windings. This not only effectively isolates the coils from the core and from each other, enhancing the insulation strength within the channels, but also helps the insulating oil circulate better, carrying away the heat generated during coil operation. The transformer coil oil channel baffles are key components for controlling oil flow paths, optimizing heat dissipation and insulation, and are of great significance for the safe and stable operation of the transformer.

[0003] Publication No. CN107749338A discloses an overload oil-immersed transformer, including an oil tank shell, a high-voltage coil, a low-voltage coil, and an iron core. The oil tank shell is a rectangular box welded from steel plates. The iron core is composed of core columns and yokes with different cross-sections. The core columns have a waist-shaped cross-section, and the yokes have a stepped rectangular cross-section. The interlayer insulation pad between the high-voltage coil and the low-voltage coil is composed of support strips and corrugated cardboard, and axial oil channels are also spaced on the interlayer insulation pad. The four walls of the oil tank shell are corrugated steel plates. The four walls of the oil tank shell are made of high-quality cold-rolled steel plates. The oil tank shell is also equipped with a pressure relief valve and a thermometer. By no longer using core columns and yokes with the same cross-section, but using core columns with small cross-sections and irregularly shaped yokes without changing the overlapping area of ​​the two, the amount of conductors can be reduced without increasing the amount of silicon steel sheets, thereby reducing the heat generated by the conductors. Furthermore, the use of spaced-out interlayer insulation pads ensures that each layer of conductors can contact the transformer oil, increasing the heat dissipation surface area and efficiency, reducing the temperature rise of the hottest spots in the coil, delaying insulation aging, and extending the transformer's service life. The high- and low-voltage coil ends employ a hard-end ring gapless support structure, enhancing the transformer's short-circuit withstand capability.

[0004] CN207637605U discloses a segmented oil channel structure for an elongated oval coil, comprising an iron core, an inner coil, an insulating cardboard, and an outer coil arranged sequentially from the inside out; several oil channel support strips are provided between the outer coil and the insulating cardboard; several oil channel support strips are arranged radially along the insulating cardboard; the insulating cardboard includes two arc segments and two first straight segments; the two arc segments and the two first straight segments form an elongated oval shape, and the arc segments overlap with the first straight segments; the overlap joint between the arc segments and the first straight segments is located between two adjacent oil channel support strips; the outer surface of the insulating cardboard has outwardly protruding positioning protrusions; the positioning protrusions are dovetail-shaped, with the inner side smaller than the outer side; the inner surface of the oil channel support strips has grooves that engage with the positioning protrusions. The oil channel support strips are bonded to the insulating cardboard. By breaking the arc segment and the first straight segment of the insulating paperboard into two segments—the first straight segment and the two arc segments—the outer coil is directly pressed against the outer coil by the oil channel support strip. This ensures that the first straight segment of the insulating paperboard fits snugly against the inner coil, preventing gaps and improving the transformer's insulation strength. Secondly, positioning protrusions are provided on the outer surface of the insulating paperboard, and slots are provided on the oil channel support strip to engage with these protrusions. This prevents the oil channel support strip from tilting, ensuring unobstructed oil channels and good coil heat dissipation. It also guarantees the pressure of the oil channel support strip on the insulating paperboard. The overlapping joint of the arc segment and the first straight segment is located between two adjacent oil channel support strips, preventing the overlapping joint from protruding outwards and causing a localized outward enlargement of the outer coil's outer surface.

[0005] The typical arrangement of channels between windings in a conventional oil-immersed transformer is an alternating cycle of oil channels and insulating cylinders. Oil channels run on both the inner and outer sides of the windings, allowing oil to flow in and out, facilitating heat flow within the windings, and supporting the coils. Channels between transformer coils are usually separated by an oil channel-partition structure. Typically, oil channels are located on both the inner and outer diameter sides of the coils, with insulating cylinders arranged sequentially. Support bars are evenly distributed within the oil channels to support the coils, and insulating cylinders separate the oil channels from each other. Generally, the size of the coil oil channels on both the inner and outer diameter sides of the windings is set within the range of 8-12mm. Support bars are placed at regular angles within the oil channels, and the insulating cylinders are insulating paperboards that encircle the windings. Based on calculations of the transformer's main insulation electric field, the breakdown probability of smaller oil channels is lower than that of larger oil channels.

[0006] The electric field between transformer coils is usually uniform or slightly non-uniform, based on the volume effect of transformer oil. Appropriate oil channel size can improve the dielectric strength of transformer oil. However, using large oil channels results in high mechanical strength and strong structural stability, but slow oil flow velocity, low electric field insulation strength, and a relatively high probability of breakdown. Using small oil channels has the opposite advantages and disadvantages. Therefore, it is difficult to balance oil flow, mechanical strength, and insulation strength simultaneously when designing coil oil channels. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a coil oil passage partition structure and an oil-immersed transformer that can simultaneously balance the problems of oil flow, mechanical strength and insulation strength.

[0008] To achieve the above objectives, the present invention discloses a coil oil channel partition structure comprising several layers of insulating cylinders distributed sequentially from the inside to the outside, wherein several oil channel support strips are provided on the outer wall of the insulating cylinders, and several oil channel partitions are provided on the oil channel support strips.

[0009] A further improvement to the coil oil passage partition structure described in this invention is as follows: Furthermore, the oil passage support bars are distributed sequentially along the circumference.

[0010] Furthermore, each oil channel support bar is parallel to the axis of the insulating cylinder.

[0011] Furthermore, the oil passage support bar has a groove, and the oil passage partition is installed into the groove.

[0012] Furthermore, the oil passage baffle is made of insulating cardboard.

[0013] This invention discloses an oil-immersed transformer, including a high-voltage coil, a medium-voltage coil, and a coil oil passage partition structure disposed between the high-voltage coil and the medium-voltage coil. The coil oil passage partition structure includes several layers of insulating cylinders distributed sequentially from the inside to the outside. Several oil passage support bars are disposed on the outer wall of the insulating cylinders, wherein several oil passage partitions are disposed on the oil passage support bars.

[0014] A further improvement of the oil-immersed transformer described in this invention is as follows: Furthermore, the oil passage baffle is disposed at the coil electrostatic ring, the coil outlet, the outer side of the coil, and at the position where the voltage at the beginning of the coil is high.

[0015] Furthermore, the oil passage support bars are distributed sequentially along the circumference.

[0016] Furthermore, each oil channel support bar is parallel to the axis of the insulating cylinder.

[0017] Furthermore, the oil passage support bar is provided with a slot for mounting the oil passage partition plate.

[0018] The present invention has the following beneficial effects: In the specific operation of the coil oil channel partition structure and oil-immersed transformer described in this invention, each insulating cylinder is distributed sequentially from the inside to the outside to form coil oil channels. Several oil channel support bars are provided on the outer wall of each insulating cylinder, with each support bar distributed sequentially along the circumference and parallel to the axis of the insulating cylinder. Several oil channel partitions are provided on each support bar, and these partitions are installed within the coil oil channels, reducing the calculated oil gap in the main insulation electric field of the coil and improving the electric field insulation margin at the installation location. Secondly, the installation method of the oil channel partitions is simple, and weak points discovered during transformer main insulation verification can be flexibly arranged within the coil oil channels, greatly reducing the workload of transformer designers. Furthermore, the coil air channel structure arrangement is similar, therefore this structure can be used for transformers with various types of insulating media. Separating the large oil gap in the coil oil channels improves the dielectric strength of the coil oil gap, reduces the probability of oil gap breakdown, and does not affect the mechanical strength and oil flow rate of the coil oil channels, reducing the calculation time for transformer main insulation electric field verification and the workload of transformer designers.

[0019] It should be noted that in this invention, the oil passage baffle is installed on the oil passage support bar in the coil oil passage. This reduces the oil gap size in the coil main insulation calculation without affecting the mechanical strength and oil flow of the coil oil passage. This improves the dielectric strength of the transformer oil, reduces the probability of oil gap breakdown, and allows for flexible adjustment. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 Here is a structural diagram of insulating cylinder 1; Figure 2 This is a structural diagram of the present invention; Figure 3 This is a diagram showing the location of oil passage baffle 3; Figure 4 This is a schematic diagram of the insulation of the coil leads.

[0022] Among them, 1 is the insulating cylinder, 2 is the oil passage support bar, 3 is the oil passage partition, 4 is the high voltage coil, 5 is the medium voltage coil, and 6 is the outgoing line. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] In the description of this invention, it should be understood that the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0025] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0026] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Additionally, the character " / " in this invention generally indicates that the preceding and following objects have an "or" relationship.

[0027] It should be understood that although terms such as first, second, third, etc., may be used in the embodiments of the present invention to describe the preset range, these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from one another. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0028] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0030] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0031] Example 1 The coil oil duct partition structure of this invention includes several layers of insulating cylinders 1 distributed sequentially from the inside out. Several oil duct support bars 2 are provided on the outer wall of each insulating cylinder 1, and several oil duct partitions 3 are provided on each oil duct support bar 2. The oil duct partitions 3 are installed inside the coil oil ducts, reducing the calculated oil gap in the main insulation electric field of the coil and improving the electric field insulation margin at the installation location. Furthermore, the installation method of the oil duct partitions 3 is simple; weak points discovered during transformer main insulation verification can be flexibly arranged within the coil oil ducts, greatly reducing the workload of transformer designers.

[0032] Example 2 To further improve this application, refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 The coil oil passage partition structure of the present invention includes several layers of insulating cylinders 1 arranged sequentially from the inside to the outside. Several oil passage support strips 2 are provided on the outer wall of the insulating cylinder 1. Each oil passage support strip 2 is arranged sequentially along the circumference and is parallel to the axis of the insulating cylinder 1. Several oil passage partitions 3 are provided on the oil passage support strip 2.

[0033] In this embodiment, the oil channel support bar 2 has a slot, and the oil channel baffle 3 is installed in the slot. The oil channel baffle 3 is made of insulating paperboard to reduce the oil gap of the coil. In actual application, the size of the oil channel baffle 3 is determined according to the insulation margin when calculating the main insulation of the oil-immersed transformer.

[0034] It should be noted that in this invention, the oil passage baffle 3 is installed on the groove of the oil passage support 2, which has the characteristics of convenient and flexible operation and does not change the mechanical strength of the support and the oil flow rate.

[0035] Example 3 To further improve this application, refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 This embodiment provides an oil-immersed transformer, which includes a high-voltage coil 4, a medium-voltage coil 5, and a coil oil passage partition structure as shown in Embodiment 1, disposed between the high-voltage coil 4 and the medium-voltage coil 5. The coil oil passage partition structure includes several layers of insulating cylinders 1 distributed sequentially from the inside to the outside. Several oil passage support bars 2 are provided on the outer wall of the insulating cylinder 1, wherein each oil passage support bar 2 is distributed sequentially along the circumference, and each oil passage support bar 2 is parallel to the axis of the insulating cylinder 1. Several oil passage partitions 3 are provided on the oil passage support bars 2.

[0036] The oil passage baffle 3 is installed at a position where the lightning gradient between coils is greater than a preset gradient, for example, reference... Figure 2 The oil passage support 2 has a slot for mounting the oil passage partition 3, dividing the oil gap on the outer diameter side of the high-voltage coil 4 to improve the insulation margin at the beginning of the outer diameter side of the high-voltage coil 4. (Reference) Figure 3 The oil duct baffle 3 is located at the bend of the lead wire 6 in the high-voltage coil 4. It provides insulation reinforcement protection at the bend of the lead wire 6 in the high-voltage coil 4, thereby improving the withstand voltage of the coil oil gap. In addition, the oil duct baffle can be set on the outside of the coil. For example, it can be used to locally reinforce the insulation baffle of the bushing, locally reinforce the protection of the surface of the core clamp, or be placed wherever there are wooden parts inside the transformer.

[0037] This invention employs a structure where an insulating partition is placed by slotting the oil channel support bar 2. This divides a large oil gap into two smaller oil gaps. The oil channel partition 3 can be flexibly placed at weak points in the coil insulation, such as the coil electrostatic ring, coil leads, and locations with high voltage at the coil's beginning. The oil channel partition 3 can be placed based on the electric field calculation results. Only local slotting of the oil channel support bar 2 is required, without adjusting the overall transformer coil design. This significantly reduces the time spent on verifying the transformer's main insulation due to insufficient electric field calculation margin, requiring readjustment of the transformer design, and re-simulation. Simultaneously, the oil flow rate and mechanical strength of the oil channel support bar 2 remain unaffected.

[0038] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and disclosure of the invention. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

[0039] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

[0040] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A coil gallery bulkhead structure, characterized by, The insulating cylinder (1) is composed of several layers of insulating cylinder, and the outer wall of the insulating cylinder (1) is provided with several oil channel support bars (2), wherein the oil channel support bar (2) is provided with several oil channel partition plates (3).

2. The coil gallery bulkhead structure of claim 1, wherein Each oil channel support bar (2) is distributed along the circumference.

3. The coil gallery bulkhead structure of claim 1, wherein, Each oil channel support bar (2) is parallel to the axis of the insulating cylinder (1).

4. The coil gallery bulkhead structure of claim 1, wherein, The oil channel support bar (2) is provided with a notch, and the oil channel partition plate (3) is installed in the notch.

5. The coil gallery bulkhead structure of claim 1, wherein, The oil channel partition plate (3) is made of insulating paper board.

6. An oil-immersed transformer, characterized by comprising: The coil oil channel partition plate structure as claimed in claim (1) is arranged between the high-voltage coil (4) and the medium-voltage coil (5).

7. The oil immersed transformer according to claim 6, characterized in that, The oil channel partition plate (3) is arranged at the position of high coil static ring, coil outlet, coil outside and high coil head voltage.

8. The oil immersed transformer according to claim 6, characterized in that, Each oil channel support bar (2) is distributed along the circumference.

9. The oil immersed transformer according to claim 6, characterized in that, Each oil channel support bar (2) is parallel to the axis of the insulating cylinder (1).

10. The oil immersed transformer as claimed in claim 6, wherein, The oil channel support bar (2) is provided with a notch for installing the oil channel partition plate (3).

Images