Star-shaped frame for bridge arm reactor and current limiting reactor

Abstract

The invention discloses a star-shaped frame for a bridge arm reactor and a current-limiting reactor, and the star-shaped frame comprises a central shaft which comprises axial grooves which are uniformly distributed in the axial direction; the axial groove comprises a lifting insertion groove, a confluence insertion groove and a star-shaped arm insertion groove; the at least three lifting arms are inserted and welded with the central shaft through the lifting slots; the confluence arm is inserted and welded with the central shaft through the confluence arm slot; a terminal plate is fixed on the confluence arm along a central shaft; the confluence arm comprises a first aluminum bar, a confluence arm reinforcing steel plate, an insulating plate and a second aluminum bar which are stacked in sequence; the star-shaped arm is inserted and welded with the central shaft through the star-shaped arm slot; and the star-shaped frame reinforcing plate is used for sequentially fixing the hoisting arm, the converging arm and the star-shaped arm in the circumferential direction by taking the central shaft as the axis. The confluence arm is manufactured into two layers of aluminum bars, and the confluence arm reinforcing steel plate and the insulating plate are arranged between the two layers of aluminum bars, so that the effect of shunting current is achieved, the phenomenon of abnormal temperature rise is avoided under the condition that the conductive cross section is reduced, stable hoisting can be performed, and stable use of the star-shaped frame is ensured.

Description

Technical Field

[0001] The invention relates to a star frame used for a bridge arm reactor and a current limiting reactor, belonging to the technical field of dry-type air-core reactors. Background Art

[0002] The current limiting reactor is a type of dry-type air-core reactor. When a large short-circuit current occurs in the circuit due to a short circuit, the reactor increases the short-circuit impedance through its own inductance, thereby suppressing the short circuit and avoiding damage to components of the circuit due to the short-circuit current. At the same time, the current limiting reactor can also maintain the bus voltage level to ensure the stability of the equipment operation in the circuit. Therefore, it is often used in power networks, such as the domestic ultra-high voltage power grid (500kV power grid).

[0003] Existing current-limiting reactors usually have problems with magnetic leakage and heating during use. This is mainly because the two cannot be well taken into account during the design process. On the one hand, in order to prevent magnetic leakage, we need to increase the conductive cross-section of the upper and lower star frames in the dry-type air-core reactor to ensure a sufficiently small current-carrying density. However, the corresponding increase in the conductive cross-section will cause the eddy current loss of the conductive bar to increase sharply, resulting in abnormal temperature rise. On the contrary, if the conductive cross-section of the upper and lower star frames in the dry-type air-core reactor is maintained or even reduced, the current-carrying density requirements will not be met, resulting in damage due to illegal bearing of electric force, and it will also affect its overall mechanical properties, such as causing problems such as inability to hoist. Summary of the invention

[0004] Therefore, an object of the present invention is to provide a star frame for a bridge arm reactor and a current limiting reactor, so as to reduce the conductive cross section and avoid abnormal heat dissipation.

[0005] In order to achieve the above object, the present invention provides a star frame for a bridge arm reactor and a current limiting reactor, comprising: The central shaft comprises at least six axial slots evenly distributed along the axial direction; the axial slots comprise a lifting slot, a confluence slot and a star arm slot; At least three lifting arms are connected and welded to the central axis through the lifting slots; A busbar arm is connected and welded to the central axis through the busbar arm slot; a terminal plate is fixed on a side of the busbar arm away from the central axis; the busbar arm comprises a first aluminum bar, a busbar arm reinforcement steel plate, an insulating plate and a second aluminum bar stacked in sequence; At least two star-shaped arms are plugged into the central axis through the star-shaped arm slots; At least six sets of star frame reinforcement plates are used to sequentially fix the lifting arm, the confluence arm and the star arm in the circumferential direction with the central axis as the axis.

[0006] Furthermore, the central axis includes 6 independent semicircular axes; the semicircular axes are arranged in a 3*2 array.

[0007] Furthermore, the lifting arm, the confluence arm and the star-shaped arm are provided with plug connectors matching the array.

[0008] Furthermore, the axial slot includes lifting slots, a confluence slot and a star-shaped arm slot that are evenly spaced.

[0009] Furthermore, the lifting arm is bolted to a reinforcing steel plate, and the lifting arm and the reinforcing steel plate are provided with a through lifting hole.

[0010] Furthermore, the lifting arm, the confluence arm and the star-shaped arm are all fixed with mounting angle plates.

[0011] Furthermore, the first aluminum bar, the busbar reinforcement steel plate, the insulation plate and the second aluminum bar are connected by stainless steel bolts.

[0012] Furthermore, the stainless steel bolt is sleeved with an insulating sleeve.

[0013] Furthermore, the insulating plate and the insulating sleeve are made of FR4 material.

[0014] By adopting the above technical scheme, the present invention proposes a star-shaped frame for bridge arm inductors and current-limiting inductors. By making the busbar arm into two layers of aluminum bars and arranging a busbar arm reinforcement steel plate and an insulating plate in the middle, the current is diverted, thereby avoiding abnormal temperature rise while reducing the conductive cross-section. At the same time, it can also be hoisted smoothly, thereby ensuring the stable use of the star-shaped frame. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic structural diagram of a star frame for a bridge arm reactor and a current limiting reactor provided by the present invention; Figure 2 A schematic structural diagram of a central axis in a star frame for a bridge arm reactor and a current limiting reactor provided by the present invention; Figure 3 A schematic structural diagram of a lifting arm in a star frame for a bridge arm reactor and a current limiting reactor provided by the present invention; Figure 4 The present invention provides a schematic structural diagram of a busbar arm in a star frame for a bridge arm reactor and a current limiting reactor.

[0016] In the figure: 1. center axis; 2. axial groove; 3. lifting arm; 4. busbar arm; 5. terminal board; 6. first aluminum bar; 7. busbar arm reinforcement steel plate; 8. insulation plate; 9. second aluminum bar; 10. star arm; 11. star frame reinforcement plate; 12. plug connector; 13. installation angle plate. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below through the accompanying drawings and specific implementation methods. The existing air-core reactors often fail to take into account the problems of magnetic leakage and heat generation during the design process. The conductive cross-section of the upper and lower star frames in the dry-type air-core reactor is increased to ensure a sufficiently small current-carrying density; but the corresponding increase in the conductive cross-section will cause the eddy current loss of the conductive bar to increase sharply, resulting in abnormal temperature rise; on the contrary, if the conductive cross-section of the upper and lower star frames in the dry-type air-core reactor is maintained or even reduced, the current-carrying density requirements will not be met, resulting in damage due to illegal bearing of electric power, and will also affect its overall mechanical properties, such as causing problems such as inability to hoist.

[0018] Example like Figures 1 to 4 As shown, the present invention provides a star frame for a bridge arm reactor and a current limiting reactor, comprising: The central axis 1 includes at least two axial grooves 2 evenly distributed along the axial direction; the axial grooves 2 include a lifting slot, a conduit slot and a star arm slot; the above-mentioned central axis 1 can adopt an integrated structure or a separate structure, and the overall connection is achieved by utilizing the connection relationship with the conduit arm 4, the star arm 10 and the lifting arm 3.

[0019] For example, the central axis 1 includes 6 independent semicircular axes, which are arranged in a 3*2 array. Specifically, the semicircular axes form three vertically arranged circular rings, namely the central axis 1, which is mainly made of aluminum.

[0020] At least three lifting arms 3 are connected and welded to the central axis 1 through the lifting slots; the lifting arms 3 are bolted with reinforcing steel plates, and the lifting arms 3 and the reinforcing steel plates are provided with through lifting holes. The opening position of the lifting hole is selected according to the actual use needs of the current limiting reactor, and is generally located in the middle of the reactor near the outer side of the package. And because the lifting arm 3 is made of aluminum, it plays a protective role by adding a reinforcing steel plate; the reinforcing steel plate can be 6mm thick and bolted to both sides of the lifting arm 3.

[0021] The busbar arm 4 is connected and welded with the central axis 1 through the slot of the busbar arm 4; a terminal plate 5 is fixed on the side of the busbar arm 4 away from the central axis 1; the busbar arm 4 includes a first aluminum row 6 stacked in sequence, a busbar arm reinforcement steel plate 7, an insulating plate 8 and a second aluminum row 9; the size of the busbar arm 4 is related to the working voltage / current of the current limiting reactor. For example, if a 500kV / 5000A hollow current limiting reactor is used, the size of the busbar arm 4 is a conventional size of 234×20 (2*10 double row) mm. Compared with the original busbar arm 4 size of 254×19 (1*19 single row) mm, its loss can be reduced to one third of the original at the same current, and the temperature rise can be reduced by 60%. The first aluminum row 6 and the second aluminum row 9 are connected by stainless steel bolts to form a whole. The stainless steel bolts are sleeved with insulating sleeves to prevent current from being conducted through the stainless steel bolts.

[0022] The insulating plate 8 and the insulating sleeve are made of FR4 material. The thickness of the insulating plate 8 is not less than 10 mm, so as to completely separate the first aluminum row 6 and the second aluminum row 9.

[0023] At the same time, the size of the central axis 1 will also be adjusted accordingly, that is, the thickness is set to 12mm, the inner radius is 150mm, and the confluence slot on the central axis 1 needs to be processed according to the specific design. To ensure the firmness of the welding, all welding heights cannot be less than 10mm.

[0024] At least two star arms 10 are connected and welded to the central axis 1 through the slots of the star arms 10; the lifting arm 3, the confluence arm 4 and the star arm 10 are provided with plug connectors 12 matching the array. The plug connectors 12 can be three protruding connecting pieces, and their function is to make the three vertically arranged circular rings form a whole; In a preferred embodiment, the axial slot 2 includes a lifting slot, a confluence slot, and a star arm slot that are evenly spaced. For example, there are 12 axial slots 2 in total, including 6 lifting slots, 1 confluence slot, and 5 star arm slots. Therefore, the star frame adopts 6 lifting arms 3, 1 confluence arm 4, and 5 star arms 10 that match the configuration of the axial slot 2.

[0025] At least six sets of star frame reinforcement plates 11 are used to fix the lifting arm 3, the confluence arm 4 and the star arm 10 in the circumferential direction with the central axis 1 as the axis. The star arm 10 reinforcement plate is made of epoxy plate, so that the star frame can be evenly stressed during the hoisting process, thereby avoiding damage during transportation or hoisting.

[0026] The lifting arm 3 , the confluence arm 4 and the star arm 10 are all fixed with mounting angle plates 13 .

[0027] Furthermore, based on the use of the aforementioned star frame, the working mode of the current limiting reactor will also be adjusted, specifically: The 5000A current is divided into two parts, which are connected to the corresponding wires through the left and right halves respectively, and the two wires also conduct a part of the current respectively.

[0028] In an alternating magnetic field, the star frame will cut the magnetic field in both the axial and radial directions to generate eddy currents. The eddy current loss is closely related to the size, conductivity, and magnetic field frequency of the star frame, as shown in the following formula: where a, b, l, are the thickness, width, length and conductivity of the star frame, is the axial radial magnetic field strength of the star frame at a certain unit point in space. ,Under the condition of certain width and length of the star frame, according to experience, the loss of the star frame of the large-capacity reactor and the thickness of the star frame are approximately related as follows: in is the star frame loss when the thickness is 1, which can be obtained by Calculated, K is the structural coefficient. Under general structure, according to experience, K≈2.5~2.8. It can be seen from formula (2) that when the thickness of the star frame increases by 1 times, the eddy current loss increases to 5.65 times (when K=2.5), and the temperature rise can increase to 4 times the original. Therefore, in ultra-large capacity current limiting reactors, the thickness of the star frame should be as small as possible, generally not exceeding 13mm, and 10mm is recommended as the preferred solution.

[0029] The present invention proposes a star-shaped frame for a bridge arm reactor and a current-limiting reactor. The current is shunted by making the busbar arm into two layers of aluminum bars and arranging a busbar arm reinforcement steel plate and an insulating plate in the middle. Furthermore, abnormal temperature rise is avoided while reducing the conductive cross-section. At the same time, the star-shaped frame can be hoisted smoothly, thereby ensuring the stable use of the star-shaped frame.

[0030] Obviously, the above embodiments are only examples for clear explanation, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from them are still within the protection scope of the invention.

Claims

1. A star frame for bridge arm reactors and current limiting reactors, characterized in that: include: The central shaft (1) comprises at least two axial slots (2) evenly distributed along the axial direction; the axial slots (2) comprise a lifting slot, a confluence slot and a star arm slot; At least three lifting arms (3) are connected and welded to the central axis (1) through the lifting slots; A busbar arm (4) is connected and welded to the central axis (1) via the busbar arm slot; a terminal plate (5) is fixed to a side of the busbar arm (4) away from the central axis (1); the busbar arm (4) comprises a first aluminum row (6), a busbar arm reinforcement steel plate (7), an insulating plate (8) and a second aluminum row (9) stacked in sequence; At least two star-shaped arms (10) are plugged and welded to the central axis (1) through the star-shaped arm slots; At least six sets of star frame reinforcement plates (11) are used to sequentially fix the lifting arm (3), the confluence arm (4) and the star arm (10) in the circumferential direction with the central axis (1) as the axis.

2. The star frame for bridge arm reactor and current limiting reactor according to claim 1, characterized in that: The central axis (1) comprises 6 independent semicircular axes; the semicircular axes are arranged in a 3*2 array.

3. The star frame for bridge arm reactor and current limiting reactor according to claim 2, characterized in that: The lifting arm (3), the confluence arm (4) and the star-shaped arm (10) are provided with plug connectors (12) matching the array.

4. The star frame for bridge arm reactor and current limiting reactor according to claim 1, characterized in that: The axial slot (2) comprises lifting slots arranged at even intervals, a confluence slot and a star-shaped arm slot.

5. The star frame for bridge arm reactor and current limiting reactor according to claim 1, characterized in that: The lifting arm (3) is bolted to a reinforcing steel plate, and a through lifting hole is provided between the lifting arm (3) and the reinforcing steel plate.

6. The star frame for bridge arm reactor and current limiting reactor according to claim 1, characterized in that: The lifting arm (3), the confluence arm (4) and the star-shaped arm (10) are all fixed with mounting angle plates (13).

7. The star frame for bridge arm reactor and current limiting reactor according to claim 1, characterized in that: The first aluminum bar (6), the busbar reinforcement steel plate (7), the insulation plate (8) and the second aluminum bar (9) are connected by stainless steel bolts.

8. The star frame for bridge arm reactor and current limiting reactor according to claim 7, characterized in that: The stainless steel bolt is sleeved with an insulating sleeve.

9. The star frame for current limiting reactor according to claim 8, characterized in that: The insulating plate (8) and the insulating sleeve are made of FR4 material.

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