Air-core reactor coil and air-core reactor using same

Abstract

The invention relates to the field of coils of inductors, in particular to an air-core reactor coil and an air-core reactor using the same. An air-core reactor comprises a shell, an air-core reactor coil is arranged in the shell and comprises a plurality of groups of concentrically arranged coils, and an axially extending heat dissipation air passage is arranged between every two radially adjacent coils, and is characterized in that the coils are of segmented structures in the axial direction, and independent coil segments are formed; each coil segment is provided with an independent packaging structure, every two adjacent independent coil segments are supported and separated through the corresponding interval supporting structure, the coil segments of the same coil are connected in series, and the problem that an existing air-core reactor is poor in heat dissipation effect is solved.

Description

Technical Field

[0001] The invention relates to the field of coils of inductors, and in particular to an air-core reactor coil and an air-core reactor using the coil. Background Art

[0002] In recent years, the capacity of my country's power grid has been continuously expanding, making the rated value of the system short-circuit capacity larger and larger. In order to limit the short-circuit current of the transmission line and protect the power equipment, the reactor must be installed. However, the harmonic content in the system is also increasing. When using conventional iron core reactors, the iron core saturation, iron core temperature rise, and noise caused by high-order harmonics have always been a major problem. Air core reactors can solve such problems, but air core reactors are often large in size and heat generation.

[0003] The patent application publication number CN107993794A discloses a heat dissipation device for air-core reactors, including a cabinet, a fan and an air-core reactor, wherein the air-core reactor is located inside the cabinet; a side of the cabinet is provided with an air duct opening, and the fan is connected to the side and is used to blow air into the cabinet through the air duct opening. The fan provides air convection to the inside of the cabinet, and the air flow inside the air-core reactor and the air flow in the space between the cabinet and the air-core reactor can take out the heat generated by the air-core reactor coil. The heat dissipation device for air-core reactors has a simple structure, and the heat dissipation is more sufficient and uniform, so the volume can be made smaller.

[0004] Although the patent has good heat dissipation effect, the use of external fans not only increases costs, but also causes a major maintenance problem, so the use of natural air cooling is becoming more and more popular. At present, the winding structure of air-core reactors is divided into two types: layer type and pancake type. Figure 1 As shown, the layered winding structure generally adds heat dissipation ducts in the axial direction of the winding and between the windings, but the heat dissipation method of this winding structure is relatively simple, and the axial length is long. When in use, heat is easily accumulated in the upper third, resulting in uneven heat distribution, which affects heat dissipation. Summary of the invention

[0005] The purpose of the present invention is to provide an air-core reactor coil to solve the problem of uneven heat distribution of existing air-core reactor coils. The present invention also provides an air-core reactor to solve the problem of poor heat dissipation effect of existing air-core reactors.

[0006] A hollow reactor coil comprises a plurality of groups of concentrically arranged coils, an axially extending heat dissipation airway is provided between two radially adjacent coils, the coil is a segmented structure in the axial direction and forms independent coil segments, each coil segment has an independent encapsulation structure, two adjacent independent coil segments are supported and separated by a spacing support structure, and the coil segments of the same coil are connected in series.

[0007] The present invention improves the existing air-core reactor coil. Specifically, the coil is set to an axially segmented structure, and each coil segment has an independent encapsulation structure. During operation, the coil segments in each encapsulation structure independently generate heat and dissipate heat independently, and the heat is not concentrated in the top third of the same coil as before, resulting in uneven heat. In order to ensure the structural strength of the coil after segmentation, a spacing support structure is also provided between adjacent coil segments to prevent the collapse of the encapsulation, etc., while avoiding heat transfer between the two encapsulations, thereby solving the problem of uneven heat distribution in the existing air-core reactor coil.

[0008] Furthermore, the spacing support structure has a communication channel communicating with radially adjacent heat dissipation channels.

[0009] The advantage is that radially adjacent heat dissipation air channels are connected through the connecting channels on the spacing support structure, so that the heat dissipation air channels in the radial direction are connected, which can better dissipate heat and optimize the heat dissipation effect.

[0010] Further, the spacing support structure is a star-shaped arm structure including arms radially extending from the center of the coil, and the space formed between the adjacent arms between two adjacent coil segments constitutes a communication channel.

[0011] Its advantages are: the support frame arm is a star-shaped arm frame, which can support adjacent coil segments of multiple coils at the same time, and under the premise of ensuring the stability of the support, the star-shaped arm frame has less obstruction to the heat dissipation airway compared to other structures, which can make the airflow flow better and optimize the heat dissipation effect.

[0012] Furthermore, the star-shaped arm structure is a star-shaped arm made of glass fiber material.

[0013] The advantages are: the star-shaped arm frame made of glass fiber has good insulation and high strength, and can provide sufficiently reliable support for each independent encapsulation structure.

[0014] Further, the same coil includes two coil segments, and the turns ratio between the coil segment on the upper side and the coil segment on the lower side ranges from 3:7 to 5:5.

[0015] The advantage is that if the turns ratio between the coil segment on the upper side and the coil segment on the lower side is too large or too small, an encapsulation structure similar to that in the prior art will be formed, and the coil segment on the upper side or the coil segment on the lower side will still have a problem of heat imbalance, so it is more appropriate to control the turns ratio between the coil segment on the upper side and the coil segment on the lower side within 3:7 to 5:5.

[0016] Furthermore, the turns ratio between the coil segment on the upper side and the coil segment on the lower side is 5:5.

[0017] The advantage is that since the turns of the multiple coils are not necessarily the same, setting the turns ratio between the upper coil segment and the lower coil segment to 5:5 can make the spacing support structure easier to install.

[0018] Furthermore, lead bars are arranged circumferentially between two radially adjacent coils, and channels between adjacent lead bars form heat dissipation channels.

[0019] The advantage is that the draw bars arranged at intervals not only support the coil but also form a heat dissipation duct. Compared with other structures, the structure is simpler and the molding is more convenient.

[0020] Furthermore, the pull-out bar is a hollow tubular structure, and the inner hole of the hollow tubular pull-out bar is axially connected.

[0021] The advantage is that the pull-out strip is a hollow tubular structure and is axially connected, forming independent heat dissipation air channels, further improving the heat dissipation effect.

[0022] Furthermore, the coil is a single-layer coil, and the wire wound around the single-layer coil is a stranded wire formed by twisting a plurality of thin wires.

[0023] The advantage is that the conductor in the package is set as a thin conductor, which can reduce the circulating current in the conductor, reduce the eddy current of the winding, and reduce the loss of the coil.

[0024] A hollow reactor comprises a shell, in which a hollow reactor coil is arranged, the hollow reactor coil comprises a plurality of groups of concentrically arranged coils, an axially extending heat dissipation airway is provided between two radially adjacent coils, and the invention is characterized in that the coil is a segmented structure in the axial direction and forms independent coil segments, each coil segment has an independent encapsulation structure, two adjacent independent coil segments are supported and separated by a spacing support structure, and the coil segments of the same coil are connected in series.

[0025] The present invention improves the prior art. Specifically, the coil of the air-core reactor is set to an axially segmented structure, and each coil segment has an independent encapsulation structure. During operation, the coil segments in each encapsulation structure generate heat independently and dissipate heat independently, and the heat is not concentrated in the top third of the coil as before, resulting in heat imbalance. In order to ensure the structural strength of the coil after segmentation, a spacing support structure is also provided between adjacent coil segments to prevent the collapse of the encapsulation, etc. The new air-core reactor coil with good heat dissipation optimizes the heat dissipation effect of the air-core reactor, solving the problem of poor heat dissipation effect of the existing air-core reactor.

[0026] Furthermore, the spacing support structure has a communication channel communicating with radially adjacent heat dissipation channels.

[0027] The advantage is that radially adjacent heat dissipation air channels are connected through the connecting channels on the spacing support structure, so that the heat dissipation air channels in the radial direction are connected, which can better dissipate heat and optimize the heat dissipation effect.

[0028] Further, the spacing support structure is a star-shaped arm structure including arms radially extending from the center of the coil, and the space formed between the adjacent arms between two adjacent coil segments constitutes a communication channel.

[0029] Its advantages are: the support frame arm is a star-shaped arm frame, which can support adjacent coil segments of multiple coils at the same time, and under the premise of ensuring the stability of the support, the star-shaped arm frame has less obstruction to the heat dissipation airway compared to other structures, which can make the airflow flow better and optimize the heat dissipation effect.

[0030] Furthermore, the star-shaped arm structure is a star-shaped arm made of glass fiber material.

[0031] The advantages are: the star-shaped arm frame made of glass fiber has good insulation and high strength, and can provide sufficiently reliable support for each independent encapsulation structure.

[0032] Further, the same coil includes two coil segments, and the turns ratio between the coil segment on the upper side and the coil segment on the lower side ranges from 3:7 to 5:5.

[0033] The advantage is that if the turns ratio between the coil segment on the upper side and the coil segment on the lower side is too large or too small, an encapsulation structure similar to that in the prior art will be formed, and the coil segment on the upper side or the coil segment on the lower side will still have a problem of heat imbalance, so it is more appropriate to control the turns ratio between the coil segment on the upper side and the coil segment on the lower side within 3:7 to 5:5.

[0034] Furthermore, the turns ratio between the coil segment on the upper side and the coil segment on the lower side is 5:5.

[0035] The advantage is that since the turns of the multiple coils are not necessarily the same, setting the turns ratio between the upper coil segment and the lower coil segment to 5:5 can make the spacing support structure easier to install.

[0036] Furthermore, lead bars are arranged circumferentially between two radially adjacent coils, and channels between adjacent lead bars form heat dissipation channels.

[0037] The advantage is that the draw bars arranged at intervals not only support the coil but also form a heat dissipation duct. Compared with other structures, the structure is simpler and the molding is more convenient.

[0038] Furthermore, the pull-out bar is a hollow tubular structure, and the inner hole of the hollow tubular pull-out bar is axially connected.

[0039] The advantage is that the pull-out strip is a hollow tubular structure and is axially connected, forming independent heat dissipation air channels, further improving the heat dissipation effect.

[0040] Furthermore, the coil is a single-layer coil, and the wire wound around the single-layer coil is a stranded wire formed by twisting a plurality of thin wires.

[0041] The advantage is that the conductor in the package is set as a thin conductor, which can reduce the circulating current in the conductor, reduce the eddy current of the winding, and reduce the loss of the coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 : A schematic diagram of the structure of an air-core reactor coil in the prior art;

[0043] Figure 2 : A structural schematic diagram of an air-core reactor coil according to Embodiment 1 of the air-core reactor of the present invention;

[0044] Figure 3 : a top view of an air-core reactor coil of Embodiment 1 of the air-core reactor of the present invention;

[0045] Figure 4 : A partially enlarged view of the air-core reactor coil of the first embodiment of the air-core reactor of the present invention.

[0046] In the figure: 1. Encapsulation structure; 11. Upper encapsulation of supporting structure; 12. Lower encapsulation of supporting structure; 2. Stranded wire; 21. Thin conductor; 3. Spacer supporting structure; 4. Pull-out bar; 5. Marble-resin mixture; 6. Six equally divided star-shaped arm frame; 7. Aluminum row arm. DETAILED DESCRIPTION

[0047] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0048] Embodiment 1 of the air-core reactor of the present invention:

[0049] like Figure 2-4As shown, the hollow reactor coil of the hollow reactor of the present invention divides a coil into two segments according to a turns ratio of 5:5, and each segment forms an independent encapsulation structure 1. A star-shaped arm frame made of glass fiber material is arranged between two axially adjacent encapsulation structures 1 as a spacing support structure 3, and the two encapsulation structures 1 are supported by the spacing support structure 3. In addition, there is a connecting channel on the spacing support structure 3 that connects the radially adjacent heat dissipation airways, which ensures the stability of each encapsulation structure 1 and realizes the penetration of the airway. In addition, a hollow drawing bar 4 is arranged between two radially adjacent windings, which supports the windings and forms an additional heat dissipation airway. The present invention divides the coil into two independent coil segments in the axial direction and forms two encapsulation structures 1, each encapsulation 1 independently dissipates heat, and the encapsulation structure 1 is supported by the spacing support structure 3, thereby ensuring the penetration of the airway, and replacing the original solid drawing bar with a hollow drawing bar 4, optimizing the heat dissipation effect, and solving the problem of uneven heat distribution of the coil of the existing hollow reactor.

[0050] like Figure 1-3 As shown, the air-core reactor coil includes three groups of coils arranged concentrically. Of course, in other embodiments, there may be four or five groups of coils or more to constitute the air-core reactor coil. The upper and lower ends of the coil are tied with six equally divided star-shaped arms 6 for supporting the winding through glass fibers. The upper and lower six equally divided star-shaped arms 6 are respectively provided with aluminum row arms 7 for connecting with the coil and realizing electrical connection with other structures. Of course, in other embodiments, there may also be star-shaped arms of other shapes, such as eight equally divided star-shaped arms or four equally divided star-shaped arms.

[0051] The coil can be wound by two layers, three layers, or four layers of wires, but in the present embodiment: according to the actual situation, a suitable number of thin wires 21 with a diameter of 1 mm are selected to be twisted into a stranded wire 2, and the stranded wire 2 is wound to form a coil. The use of thin wires 21 can reduce the circulating current of the wires and thus reduce the eddy current of the coil, thereby achieving the purpose of reducing losses. The stranded wire 21 is set to be a thin wire 21 with a diameter of 1 mm because the thin wire 21 of this diameter can greatly reduce the influence of eddy currents, and at the same time, the production cost of the thin wire 21 of this diameter will not be too high. Of course, in other embodiments, the diameter of the appropriate thin wire 21 can also be selected according to the actual situation, as long as the diameter is smaller than the 1.5 mm diameter wire used in the prior art.

[0052] The coil is divided into two segments according to a turns ratio of 5:5, and each forms an independent encapsulation structure 1. Two adjacent encapsulation structures 1, i.e., two adjacent segments of the same coil, are connected in series through a twisted wire 2, and a spacing support structure 3 is provided between two axially adjacent encapsulations 1. The spacing support structure has a connecting channel connecting radially adjacent heat dissipation airways. The encapsulation structures 1 on both sides of the spacing support structure 3 are the lower encapsulation 12 of the spacing support structure and the upper encapsulation 11 of the spacing support structure. Of course, the coil can also be divided into more segments, for example: three segments, four segments or more. Dividing the coil into more segments will not greatly improve the solution to the uneven heat distribution, but will increase the workload and cost; and if there are too many segments, there will be more spacing support structures 3, which will cause the air-core reactor coil to be too high and the air-core reactor to be too large. Therefore, a coil is divided into two segments and a spacing support structure 3 is provided.

[0053] The spacing support structure 3 is a star-shaped arm made of glass fiber. The spacing support structure 3 is a star-shaped arm, which can support adjacent coil segments of multiple coils at the same time. Moreover, under the premise of ensuring the stability of the support, the star-shaped arm has less obstruction to the heat dissipation airway than other structures, which can make the air flow better and optimize the heat dissipation effect. The star-shaped arm made of glass fiber has good insulation and high strength, and can provide sufficiently reliable support for each independent encapsulation structure. Of course, in other embodiments, other materials can also be used to make the spacing support structure 3, such as resin, as long as the requirements for insulation performance and strength are met.

[0054] The encapsulation structure 1 is also filled with a marble resin mixture 5, which can better fix the stranded wire 2 and prevent the stranded wire 2 from shifting when the equipment vibrates, thereby increasing the loss. A pull-out bar 4 is also provided between the coils, which penetrates the lower encapsulation 12 of the spacing support structure and the upper encapsulation 11 of the spacing support structure. The pull-out bars 4 are evenly arranged on the circumference, and a certain distance is left between the pull-out bars 4 to form a heat dissipation airway. The pull-out bars 4 are provided to support the encapsulation structure 1, and are arranged at intervals to ensure that there is a gap between the encapsulation structures 1 to form a heat dissipation airway. The pull-out bars 4 can be provided as solid glass fiber pull-out bars. However, in the present embodiment, the pull-out bars 4 are hollow tubular structures, and the inner hole of the hollow tubular structure is axially penetrated. The pull-out bars 4 are hollow tubular structures and are axially penetrated. The pull-out bars 4 are provided as hollow tubular structures and are axially penetrated, forming independent heat dissipation airways, further improving the heat dissipation effect. The pull-out bar 4 is made of marble, which can ensure that the pull-out bar 4 has sufficient structural strength to support the encapsulation structure 1 even when it is set to be hollow.

[0055] During production, first place the six equally divided star-shaped arms 6 and the spacing support structure 3 at the upper and lower ends into the mold, and then start to wind the radially innermost coil, starting from the lower section and ensuring that the stranded wire 2 is close to the arms of the spacing support structure 3 and enters above the spacing support structure 3. Then continue winding until the entire coil is formed. Then the entire coil is packaged. After the packaging is completed, the pull-out bar 4 is placed next to the coil. After the pull-out bar 4 is placed, the sand winding operation is performed to fix the pull-out bar 4 to the first group of coils. Then the second group of coils is wound according to the above method until all the coils and the pull-out bars 4 are assembled. Then the stranded wires 2 extending from both ends of all the coils are welded in parallel to the aluminum row arms 7 on the six equally divided star-shaped arms 6 at the upper and lower ends.

[0056] The present invention divides the coil into two sections in the axial direction, and each section of the coil has an encapsulation structure 1, and a star-shaped arm frame made of glass fiber is arranged between two adjacent encapsulation structures 1 in the axial direction as a spacing support structure 3, so that each encapsulation structure 1 can dissipate heat independently, and heat will not be concentrated in the upper third of the coil. The pull-out bar 4 is also arranged as an axially through structure, which further optimizes the heat dissipation and solves the problem of poor heat dissipation effect of the existing air-core reactor.

[0057] Embodiment 2 of the air-core reactor of the present invention: The difference between this embodiment and embodiment 1 is that the spacing support structure is a spacer block, and two axially adjacent enclosures are supported by the spacer blocks.

[0058] Embodiment 3 of the air-core reactor of the present invention: The difference between this embodiment and embodiment 1 is that the turn ratio of the upper encapsulation of the spacing support structure to the lower encapsulation of the spacing support structure is 4:6. Of course, in other embodiments, the turn ratio of the upper encapsulation of the spacing support structure to the lower encapsulation of the spacing support structure can be 2:8, 6:4, etc., but in order to ensure uniform heat distribution, it is best to control the turn ratio of the upper encapsulation of the spacing support structure to the lower encapsulation of the spacing support structure within 3:7 to 5:5.

[0059] Embodiment 4 of the air-core reactor of the present invention: The difference between this embodiment and embodiment 1 is that in this embodiment, the spacing support structure is an annular plate, and an annular plate with a width consistent with the encapsulation width of the coil is arranged between two axially adjacent coil segments, and a threading hole is provided on the annular plate for the wire to pass through and realize the connection between the two adjacent coil segments.

[0060] The embodiment of the air-core reactor coil of the present invention has the same specific structure as the air-core reactor coil structure in the embodiment of the air-core reactor introduced above, and will not be described in detail herein.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention shall be based on the claims. All equivalent structural changes made using the contents of the description and drawings of the present invention should also be included in the protection scope of the present invention.

Claims

1. An air-core reactor coil, comprising a plurality of groups of concentrically arranged coils, wherein an axially extending heat dissipation air channel is provided between two radially adjacent coils, and characterized in that: The coil is a segmented structure in the axial direction and forms independent coil segments. Each coil segment has an independent encapsulation structure (1). Two adjacent independent coil segments are supported and separated by a spacing support structure (3). The coil segments of the same coil are connected in series.

2. The air-core reactor coil according to claim 1, characterized in that: The spacing support structure (3) is provided with a communication channel for communicating with radially adjacent heat dissipation air channels.

3. The air-core reactor coil according to claim 2, characterized in that: The spacing support structure (3) is a star-shaped arm frame structure including arms radially extending from the center of the coil, and the space formed between adjacent arms between two adjacent coil segments constitutes a connecting channel.

4. The air-core reactor coil according to claim 3, characterized in that: The star-shaped arm structure is a glass fiber star-shaped arm structure.

5. The air-core reactor coil according to claim 1, characterized in that: The same coil includes two coil segments, and the turns ratio between the coil segment on the upper side and the coil segment on the lower side ranges from 3:7 to 5:

5.

6. The air-core reactor coil according to claim 5, characterized in that: The turns ratio between the upper coil segment and the lower coil segment is 5:

5.

7. The air-core reactor coil according to any one of claims 1 to 6, characterized in that: Drawing bars (4) are arranged circumferentially between two radially adjacent coils, and the channels between adjacent drawing bars (4) form the heat dissipation air channel.

8. The air-core reactor coil according to claim 7, characterized in that: The pull-out strip (4) is a hollow tubular structure, and the inner hole of the hollow tubular pull-out strip (4) is axially continuous.

9. The air-core reactor coil according to any one of claims 1 to 6, characterized in that: The coil is a single-layer coil, and the conductor wound around the single-layer coil is a twisted wire (2) formed by twisting a plurality of thin conductors (21).

10. An air-core reactor, comprising a shell, in which an air-core reactor coil is arranged, characterized in that: The air-core reactor coil is the air-core reactor coil according to any one of claims 1 to 9.

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