A regulating and compensating reactor and its coil structure

Abstract

The application provides a regulating capacity reactor and a coil structure thereof, and the coil structure comprises a first coil, a second coil and a third coil which are concentrically arranged; the first coil and the second coil are connected in parallel and then connected in series with the third coil to form a large-capacity coil; the first coil and the second coil are connected in series and then connected in series with the third coil to form a small-capacity coil; the cross-sectional area of the electromagnetic wire or the conductive foil of the first coil and the second coil is 1 / 2 of that of the third coil; and the turn ratio of the large-capacity coil to the small-capacity coil is The application can realize the large-capacity and small-capacity reactors by the parallel and series connection of the coils and by using only the raw materials of the large-capacity reactor, so that the cost of the reactor is reduced.

Description

Technical Field

[0001] This invention relates to the field of adjustable-capacity reactor technology, and in particular to an adjustable-capacity reactor and its coil structure. Background Technology

[0002] Reactors are one of the main components in reactive power compensation devices in power systems. They are connected in series with capacitors in the system. When capacitors are being compensated, they are often affected by harmonic currents, inrush currents, and switching overvoltages, which can damage the capacitors and reduce the power factor. Therefore, it is necessary to install series reactors at the front end of the capacitors to suppress inrush currents and absorb harmonics, so as to avoid the adverse effects of harmonic currents and other factors on the capacitors and thus protect the safe and stable operation of the compensation device.

[0003] Increasing the number of stages in a conventional reactive power compensation system requires increasing the number of reactors to match it, which significantly increases the overall cost of the system. Currently, most adjustable-capacity reactors on the market adjust their capacity by selecting coil taps to change the number of coil turns or changing the number of series connections. This type of adjustment scheme greatly increases the material cost of the reactor.

[0004] In conclusion, it is of great significance to design a reactor that can adjust its capacity without increasing the material cost of the reactor. Summary of the Invention

[0005] This invention proposes a variable-capacity reactor and its coil structure. By using parallel and series connection of some coils, reactors of two different capacities can be realized using only raw materials for large-capacity reactors, thereby reducing the cost of reactors.

[0006] The technical solution of this invention is implemented as follows: A coil structure for a variable-capacity reactor includes a first coil, a second coil, and a third coil arranged concentrically. The first and second coils are connected in parallel and then in series with the third coil to form a large-capacity coil. The first and second coils are also connected in series and then in series with the third coil to form a small-capacity coil. The cross-sectional area of ​​the electromagnetic wire or conductive foil of the first and second coils is half that of the third coil. The turns ratio of the large-capacity coil to the small-capacity coil is... , n>1.

[0007] Furthermore, the first, second, and third coils are all wound with electromagnetic wire. The first and second coils are filled with an even number of layers, and both have wires entering and exiting from the top, while the third coil exits from the top.

[0008] Furthermore, the first coil and the second coil are wound simultaneously in an axial or radial arrangement, with the first coil and the second coil being insulated from each other, and the third coil being placed outside the first coil and the second coil.

[0009] Furthermore, insulating cardboard is placed between the two electromagnetic wires at the beginning and end of the first and second coils, and they are bound with heat shrink tape.

[0010] Furthermore, the first, second, and third coils are all wound with conductive foil, and the ends of the conductive foil are welded with external leads. The tops of the first, second, and third coils are all connected to and out of the external leads, and the external leads are insulated from each other.

[0011] Furthermore, the first coil and the second coil are wound simultaneously in a radial arrangement and in parallel, with the first coil and the second coil being insulated from each other. The third coil is placed outside the first coil and the second coil, and each layer of the third coil is insulated from each other.

[0012] Furthermore, the first coil and the second coil are wound simultaneously in an axially arranged manner, with insulation provided at the axial junction of the first coil and the second coil, and the third coil is placed outside the first coil and the second coil.

[0013] Furthermore, the layers of the first, second, and third coils are all insulated from each other.

[0014] An adjustable-capacity reactor includes the aforementioned coil structure, which is connected in series with a vacuum switch. An oil cut-off switch is provided between the two starting ends of the first coil and the two ending ends of the second coil, as well as between the ending end of the first coil and the starting end of the second coil.

[0015] A variable-capacity reactor further includes an upper yoke and a lower yoke, with several core columns disposed between the upper and lower yokes. A coil structure is fitted onto the outside of the core columns. Each core column includes multiple vertically stacked iron discs. A fixed air gap is provided between adjacent iron discs. The iron discs above and below the fixed air gap are connected by a first conductive sheet. An adjustable air gap is provided between the top iron disc and the upper yoke. The top iron disc is connected to the upper yoke by a second conductive sheet. The bottom iron disc is placed on the lower yoke.

[0016] Furthermore, an upper clamp is provided on the outer side of the upper yoke, and a lower clamp is provided on the outer side of the lower yoke. The upper clamp and the lower clamp are connected by a tie rod.

[0017] The beneficial effects of this invention are: The coil structure of this invention's adjustable reactor, through the parallel and series connection of some coils, allows for the production of reactors with two different capacities using only the raw materials of large-capacity reactors. Conventional adjustable reactors, however, require winding a large-capacity coil first, and then continuing to wind the remaining turns according to the smaller capacity and current carrying capacity. The coil structure of this invention eliminates the need to wind a smaller-capacity coil after the large-capacity coil is wound, thus significantly reducing reactor costs.

[0018] Furthermore, when using electromagnetic wire to wind the coil, the coil structure places the first and second coils, which have smaller cross-sectional areas, inside, and the third coil, which has a larger cross-sectional area, on the outside. This arrangement allows the larger cross-sectional area electromagnetic wire to have a smaller curvature during winding, making its insulation less prone to damage. When using conductive foil to wind the coil, placing the first and second coils, which are in an upper and lower structure, inside makes them easier to clamp and prevents them from shifting.

[0019] The adjustable reactor of the present invention uses conductive foil, such as copper foil, to connect the iron discs above and below the fixed air gap and the upper yoke and iron disc at the air gap adjustment point. This can prevent the reactor from being prone to discharge due to the floating potential caused by the air gaps above and below the iron discs during operation.

[0020] The adjustable capacity reactor of this invention uses a combination of vacuum switch and oil cut-off switch, which achieves oil non-contamination, avoids the frequent oil filtration maintenance of pure oil cut-off switch, and also avoids the problems of high cost and large size of pure vacuum adjustable capacity switch. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of the adjustable-capacity reactor of the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the structure of the adjustable-capacity reactor of the present invention. Figure 2 ; Figure 3 This is a schematic diagram of the coil structure of the present invention; Figure 4 The diagram shows the series and parallel structure of the coil. (a) is the circuit diagram connecting the oil cut-off switch and the coil. (b) is the parallel circuit diagram of the first coil and the second coil. (c) is the series circuit diagram of the first coil and the second coil. Figure 5 Schematic diagram of the arrangement of the first coil, second coil, and third coil; Figure 6 The diagram shows the unfolded arrangement of the coils made of conductive foil. (a) shows the first and second coils arranged axially in the vertical direction, and (b) shows the first and second coils arranged radially. Figure 7 This refers to the timing sequence of the vacuum switch and oil cut-off switch during the capacity adjustment and switching of the adjustable reactor.

[0023] Upper clamp 1, coil structure 2, first conductive sheet 3, upper yoke 4, lower yoke 5, iron disc 6, fixed air gap 7, adjustable air gap 8, second conductive sheet 9, lower clamp 10, pull rod 11, first coil 12, second coil 13, third coil 14, vacuum switch 15, oil cut-off switch 16, conductive foil 17, external lead-out bar 18. Detailed Implementation

[0024] 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 embodiments of the present invention, and not all embodiments. 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.

[0025] The terms "upper" and "lower" in this invention are relative to... Figure 1 The positional relationship is shown.

[0026] Example 1 like Figure 3 As shown, a coil structure for a variable-capacity reactor includes a first coil 12, a second coil 13, and a third coil 14 arranged concentrically. Figure 4 As shown in Figure a, the first coil 12 and the second coil 13 are connected in series or in parallel, and then connected in series with the third coil 14.

[0027] like Figure 4 As shown in b, the first coil 12 and the second coil 13 are connected in parallel and then connected in series with the third coil 14 to form the large-capacity coil of the adjustable-capacity reactor; as shown in b. Figure 4 As shown in Figure c, the first coil 12 and the second coil 13 are connected in series, and then connected in series with the third coil 14 to form the small-capacity coil of the adjustable-capacity reactor. By using the method of parallel and series connection of some coils, reactors of two different capacities can be realized using only the raw materials of large-capacity reactors. The adjustable-capacity reactor designed in this invention reduces the material cost of the reactor body by about 40% compared to using two reactors with half capacity.

[0028] The cross-sectional area of ​​the electromagnetic wire or conductive foil 17 of the first coil 12 and the second coil 13 is half that of the third coil 14. The turns ratio of the large-capacity coil to the small-capacity coil is... If n>1, and n=2, the cross-sectional area of ​​the electromagnetic wire used in the first coil 12 and the second coil 13 is half that of the third coil 14, and the ratio of the number of turns of the large-capacity coil to the small-capacity coil is... This invention achieves a capacity ratio of 2:1 between the large-capacity coil and the small-capacity coil, eliminating the need to wind a small-capacity coil after the large-capacity coil is wound. In contrast, conventional adjustable reactors require winding a large-capacity coil first, then continuing to wind the remaining turns according to the small-capacity coil's turn count and current carrying capacity. This means that after winding the large-capacity coil, 0.414 times the number of small-capacity turns are needed, increasing coil material costs by approximately 25%. Therefore, this invention significantly reduces reactor costs.

[0029] Other capacity ratio adjustable reactors can also be designed as needed, such as n=3, where the turns ratio of the large-capacity coil to the small-capacity coil is changed. Therefore, the ratio of the capacity of the large-capacity coil to that of the small-capacity coil is 3:1.

[0030] Example 2 This embodiment is basically the same as Embodiment 1, except that: the first coil 12, the second coil 13, and the third coil 14 are all wound with electromagnetic wire, such as... Figure 5 As shown, the first coil 12 and the second coil 13 are wound simultaneously in an axial or radial arrangement, and are insulated from each other. In an axial arrangement, the electromagnetic wires used for the first coil 12 and the second coil 13 are wound simultaneously in a top-bottom parallel manner; in a radial arrangement, the electromagnetic wires used for the first coil 12 and the second coil 13 are wound simultaneously in a left-right parallel manner.

[0031] like Figure 3 As shown, the first coil 12 and the second coil 13 are located inside the entire coil, while the third coil 14 is placed outside the first coil 12 and the second coil 13. The coil structure places the first coil 12 and the second coil 13, which have smaller cross-sectional areas of the electromagnetic wire, inside, and the third coil 14, which has a larger cross-sectional area, on the outside. This arrangement allows the larger cross-sectional area electromagnetic wire to have a smaller curvature during winding, making its insulation less prone to damage.

[0032] At the beginning and end of the first coil 12 and the second coil 13, in addition to the insulation of their respective electromagnetic wires, insulating cardboard of 0.5mm or more is wrapped around the adjacent area between one electromagnetic wire and the other electromagnetic wire, and then bound with heat shrink tape. The increased insulation at the exit point meets the insulation strength requirements at the exit point when the first coil 12 and the second coil 13 are connected in series. The electromagnetic wire itself is used for insulation between the first coil 12 and the second coil 13.

[0033] The first coil 12 and the second coil 13 are filled with an even number of layers (the number of layers in the coil is even), and both enter and exit from the top. The third coil 14 exits from the top (as shown in the image). Figure 3As shown in the diagram, this structure design makes the leads of the adjustable reactor body and the adjustable combination switch relatively simple. In addition, the adjacent layers of the first coil 12, the adjacent layers of the second coil 13, and the adjacent layers of the third coil 14 are all insulated, such as by using 3 layers of 0.08mm cable paper or 1 layer of 0.15mm AMA composite insulation material.

[0034] Example 3 This embodiment is basically the same as embodiment 2, except that: the first coil 12, the second coil 13, and the third coil 14 are all wound with conductive foil 17, such as copper foil. Figure 6 As shown in b, the first coil 12 and the second coil 13 are wound simultaneously in a radial arrangement. During the winding, the insulation between the first coil 12 and the second coil 13 is made of cardboard with the same thickness as the copper foil or 0.1 mm less. Here, the middle part refers to the space between the adjacent conductive foils 17 of the first coil 12 and the second coil 13.

[0035] The third coil 14 is placed outside the first coil 12 and the second coil 13. The adjacent conductive foils 17 of the third coil 14 are insulated, such as by using 3 layers of 0.08mm cable paper or 1 layer of 0.15mm AMA composite insulation material.

[0036] Both ends of the conductive foil 17 are welded with external leads 18. If the conductive foil 17 is copper foil, then the external leads 18 is copper busbar. The tops of the first coil 12, the second coil 13 and the third coil 14 are all connected to and out of the external leads 18. The external leads 18 are insulated from each other, such as by using 1mm cardboard insulation.

[0037] This embodiment is basically the same as embodiment 3, except that: Figure 6 As shown in Figure a, the first coil 12 and the second coil 13 are wound together with conductive foil 17 arranged vertically along the axial direction, and the middle section is insulated. Here, the middle section refers to the junction where the first coil 12 and the second coil 13 are arranged vertically along the axial direction. When winding the foil, placing the first coil 12 and the second coil 13 with the vertical structure inside makes them easier to clamp and prevents them from shifting. The adjacent conductive foil 17 layers of the first coil 12, the adjacent conductive foil 17 layers of the second coil 13, and the adjacent conductive foil 17 layers of the third coil 14 are all insulated, such as by using three layers of 0.08mm cable paper or one layer of 0.15mm AMA composite insulation material.

[0038] The lower external lead-in 18 passes through the upper coil by wrapping the lower coil's inlet and outlet wires with cardboard of 0.5mm or more.

[0039] Example 5 A variable capacitance reactor includes the coil structure 2 described in any one of embodiments 1-4, such as Figure 4As shown in Figure a, the coil structure 2 is connected in series with the vacuum switch 15. An oil cut-off switch 16 is provided between the two starting ends of the first coil 12 and the second coil 13, between the two ending ends, and between the ending end of the first coil 12 and the starting end of the second coil 13. The three oil cut-off switches 16 are used to switch the first coil 12 and the second coil 13 in series and parallel.

[0040] Vacuum switch 15 and oil circuit breaker 16 form a capacity-adjusting combination switch. Vacuum switch 15 is used to disconnect the circuit before oil circuit breaker 16 operates to ensure that oil circuit breaker 16 is not energized when it operates. After the oil circuit breaker operates, vacuum switch 15 is closed to connect the circuit. The operating sequence of vacuum switch 15 and oil circuit breaker 16 during capacity adjustment of the adjustable reactor is shown below. Figure 7 The combination of vacuum switch 15 and oil cut-off switch 16 achieves oil non-contamination, avoids the need for frequent oil filtration maintenance of pure oil cut-off switch 16, and also avoids the problems of high cost and large size of full-vacuum air conditioning capacitor switch.

[0041] like Figure 1 and 2 As shown, a variable-capacity reactor further includes an upper yoke 4 and a lower yoke 5. Several core columns, such as three core columns arranged side-by-side, are disposed between the upper yoke 4 and the lower yoke 5. The coil structure 2 is fitted onto the outside of the core columns. Each core column includes multiple vertically stacked iron discs 6, such as three vertically stacked iron discs 6. A fixed air gap 7 is provided between adjacent iron discs 6. Adjacent iron discs 6 are separated by an insulating plate of fixed thickness to form the fixed air gap 7. The iron discs 6 above and below the fixed air gap 7 are connected by a first conductive sheet 3. An adjustable air gap 8 is provided between the top iron disc 6 and the upper yoke 4. The size of the air gap can be adjusted as needed. Specifically, an insulating plate of appropriate thickness can be used to separate the top iron disc 6 and the upper yoke 4 to form the adjustable air gap 8. The top iron disc 6 is connected to the upper yoke 4 by a second conductive sheet 9. The bottom iron disc 6 is placed on the lower yoke 5, and the upper yoke 4 is single-point grounded. The first conductive sheet 3 and the second conductive sheet 9 are both conductive foils such as copper foil. By setting the first conductive sheet 3 and the second conductive sheet 9, the problem of easy discharge due to the floating potential caused by the air gaps on the top and bottom of the iron disc 6 during reactor operation can be prevented.

[0042] The upper yoke 4 is fitted with an upper clamp 1 on its outer side, and the lower yoke 5 is fitted with a lower clamp 10 on its outer side. The upper clamp 1 and the lower clamp 10 are connected by a pull rod 11. Through the cooperation of the upper clamp 1, the lower clamp 10 and the pull rod 11, the upper yoke 4, the core column and the lower yoke 5 are fixed together.

[0043] The adjustable-capacity reactor can be designed as a single-phase reactor or a three-phase reactor. This embodiment is an oil-immersed adjustable-capacity reactor. The aforementioned cardboard or cable paper can be replaced with dry-type materials to design a dry-type adjustable-capacity reactor and its coil structure.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A coil structure for a variable-capacity reactor, characterized in that: The coil consists of a first coil, a second coil, and a third coil arranged concentrically. The first and second coils are connected in parallel and then in series with the third coil to form a large-capacity coil. The first and second coils are also connected in series and then in series with the third coil to form a small-capacity coil. The cross-sectional area of ​​the electromagnetic wire or conductive foil in both the first and second coils is half that of the third coil. The turns ratio of the large-capacity coil to the small-capacity coil is... , n>

1.

2. The coil structure of a variable-capacity reactor according to claim 1, characterized in that: The first, second, and third coils are all wound with electromagnetic wire. The first and second coils are filled with an even number of layers, and both have wires entering and exiting from the top. The third coil exits from the top.

3. The coil structure of a variable-capacity reactor according to claim 2, characterized in that: The first and second coils are wound simultaneously in an axial or radial arrangement, and are insulated from each other. Insulating cardboard is placed between the two electromagnetic wires at the beginning and end of the first and second coils and they are bound with heat shrink tape. The third coil is placed outside the first and second coils.

4. The coil structure of a variable-capacity reactor according to claim 1, characterized in that: The first, second, and third coils are all wound with conductive foil, and the ends of the conductive foil are welded with external leads. The tops of the first, second, and third coils are all connected to and out of the external leads, which are insulated from each other.

5. The coil structure of a variable-capacity reactor according to claim 1, characterized in that: The first and second coils are wound simultaneously in a radial arrangement, with the first and second coils insulated from each other, and the third coil is placed outside the first and second coils.

6. The coil structure of a variable-capacity reactor according to claim 1, characterized in that: The first and second coils are wound simultaneously in an axially arranged manner, with insulation provided at the axial junction of the first and second coils, and the third coil is placed outside the first and second coils.

7. The coil structure of a variable-capacity reactor according to any one of claims 1-6, characterized in that: The layers of the first, second, and third coils are all insulated from each other.

8. A variable-capacity reactor, characterized in that, The coil structure includes the coil structure described in any one of claims 1-7, wherein the coil structure is connected in series with a vacuum switch, and an oil cut-off switch is provided between the two starting ends of the first coil and the second coil, between the two ending ends, and between the ending end of the first coil and the starting end of the second coil.

9. A variable-capacity reactor according to claim 8, characterized in that, It also includes an upper yoke and a lower yoke, with several core pillars set between the upper and lower yokes. The coil structure is fitted on the outside of the core pillars. The core pillars include multiple vertically stacked iron discs. A fixed air gap is set between adjacent iron discs. The iron discs above and below the fixed air gap are connected by a first conductive sheet. An adjustable air gap is set between the top iron disc and the upper yoke. The top iron disc is connected to the upper yoke by a second conductive sheet. The bottom iron disc is placed on the lower yoke.

10. A variable-capacity reactor according to claim 9, characterized in that, An upper clamp is provided on the outer side of the upper yoke, and a lower clamp is provided on the outer side of the lower yoke. The upper clamp and the lower clamp are connected by a tie rod.

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