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

Abstract

The utility model 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 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] This utility model relates to a star-shaped frame for bridge arm reactors and current-limiting reactors, belonging to the technical field of dry-type air-core reactors. Background Technology

[0002] Current-limiting reactors are a type of dry-type air-core reactor. They are used to increase short-circuit impedance through their own inductive reactance when a large short-circuit current occurs in the circuit due to a short circuit, thereby suppressing the short circuit and preventing damage to components caused by the short-circuit current. At the same time, current-limiting reactors can also maintain the bus voltage level and ensure the stability of equipment operation in the circuit. Therefore, they are often used in power networks, such as the domestic ultra-high voltage power grid (500kV power grid).

[0003] Current-limiting reactors often experience problems such as magnetic leakage and overheating during use. This is mainly because these two issues cannot be well balanced during the design process. On the one hand, to prevent magnetic leakage, we need to increase the conductive cross-section of the upper and lower star-shaped components in the dry-type air-core reactor to ensure a sufficiently small current density. However, increasing the conductive cross-section will lead to a sharp increase in eddy current losses in the busbars, resulting in abnormal temperature rise. Conversely, if the conductive cross-section of the upper and lower star-shaped components in the dry-type air-core reactor is maintained or even reduced, the current density requirement will not be met, leading to damage due to unauthorized electromagnetic forces. It will also affect its overall mechanical properties, such as making it impossible to hoist. Utility Model Content

[0004] Therefore, the purpose of this utility model is to provide a star-shaped frame for bridge arm reactors and current-limiting reactors, so as to reduce the conductive cross section while avoiding abnormal heat dissipation.

[0005] To achieve the above objectives, this utility model provides a star-shaped frame for bridge arm reactors and current-limiting reactors, comprising:

[0006] The central shaft includes at least six axial grooves evenly distributed along the axial direction; the axial grooves include lifting slots, manifold slots, and star-shaped arm slots.

[0007] At least three lifting booms are connected and welded to the central shaft via the lifting slots;

[0008] The busbar is plugged into and welded to the central shaft via the busbar slot; a terminal plate is fixed to the side of the busbar away from the central shaft; the busbar includes a first aluminum busbar, a busbar reinforcing steel plate, an insulating plate, and a second aluminum busbar stacked in sequence;

[0009] At least two star-shaped arms are inserted into the central shaft through the star-shaped arm slots;

[0010] At least six sets of star-shaped frame reinforcing plates are used to fix the lifting arm, the confluence arm, and the star-shaped arm in a circumferential direction with the central axis as the axis.

[0011] Furthermore, the central axis comprises six independent semicircular axes; the semicircular axes are arranged in a 3*2 array.

[0012] Furthermore, the lifting arm, the bus arm, and the star arm are provided with connectors that match the array.

[0013] Furthermore, the axial groove includes a lifting slot, a manifold, and a star-shaped arm slot, all evenly spaced.

[0014] 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.

[0015] Furthermore, the lifting boom, the confluence boom, and the star-shaped boom are all fixed with mounting angle plates.

[0016] Furthermore, the first aluminum busbar, the busbar arm reinforcing steel plate, the insulating plate, and the second aluminum busbar are connected by stainless steel bolts.

[0017] Furthermore, the stainless steel bolt is fitted with an insulating sleeve.

[0018] Furthermore, the insulating board and insulating sleeve are made of FR-4 material.

[0019] By adopting the above technical solution, this utility model proposes a star-shaped frame for bridge arm reactors and current-limiting reactors. By making the busbar into two layers of aluminum bars and setting a busbar reinforcement steel plate and an insulating plate in the middle, the current is diverted. This reduces the conductive cross-section, avoids abnormal temperature rise, and allows for stable hoisting, thus ensuring the stable use of the star-shaped frame. Attached Figure Description

[0020] Figure 1 A schematic diagram of a star-shaped frame for bridge arm reactors and current-limiting reactors provided by this utility model;

[0021] Figure 2 A schematic diagram of the structure of the central shaft in a star-shaped frame for bridge arm reactors and current-limiting reactors provided by this utility model;

[0022] Figure 3 A schematic diagram of the structure of the lifting arm in the star-shaped frame used for bridge arm reactors and current-limiting reactors provided by this utility model;

[0023] Figure 4 This utility model provides a structural schematic diagram of a busbar arm in a star-shaped frame used for bridge arm reactors and current-limiting reactors.

[0024] In the diagram: 1. Central shaft; 2. Axial groove; 3. Lifting arm; 4. Combination arm; 5. Terminal block; 6. First aluminum busbar; 7. Combination arm reinforcing steel plate; 8. Insulating plate; 9. Second aluminum busbar; 10. Star-shaped arm; 11. Star-shaped frame reinforcing plate; 12. Connector; 13. Mounting angle plate. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Existing air-core reactors often fail to address both leakage flux and heat generation during the design process. Increasing the conductive cross-section of the upper and lower star-shaped components in a dry-type air-core reactor can ensure a sufficiently small current density; however, this corresponding increase in conductive cross-section leads to a sharp increase in eddy current losses in the busbars, resulting in abnormal temperature rise. Conversely, maintaining or even reducing the conductive cross-section of the upper and lower star-shaped components in a dry-type air-core reactor will fail to meet the current density requirements, leading to damage due to unauthorized electromagnetic forces and affecting its overall mechanical properties, such as making hoisting impossible.

[0026] Example

[0027] like Figures 1 to 4 As shown, this utility model provides a star-shaped frame for bridge arm reactors and current-limiting reactors, comprising:

[0028] The central shaft 1 includes at least two axial grooves 2 evenly distributed along the axial direction; the axial grooves 2 include a lifting slot, a manifold slot, and a star-shaped arm slot; the central shaft 1 can be an integral structure or a separate structure, and the overall connection is achieved by the connection relationship with the manifold arm 4, the star-shaped arm 10, and the lifting arm 3.

[0029] For example, the central axis 1 includes 6 independent semicircular shafts; the semicircular shafts are arranged in a 3*2 array. Specifically, the semicircular shafts form three vertically arranged rings, namely the central axis 1, which is mainly made of aluminum.

[0030] At least three lifting arms 3 are connected and welded to the central shaft 1 via lifting slots. Each lifting arm 3 is bolted to a reinforcing steel plate, and the lifting arms 3 and the reinforcing steel plate have through lifting holes. The location of the lifting holes is selected according to the actual needs of the current-limiting reactor, generally located in the outer part of the reactor's middle enclosure. Since the lifting arms 3 are made of aluminum, the addition of reinforcing steel plates provides protection; the reinforcing steel plates can be 6mm thick and are bolted to both sides of the lifting arms 3.

[0031] The busbar 4 is connected to the central shaft 1 via a slot. A terminal plate 5 is fixed to the side of the busbar 4 away from the central shaft 1. The busbar 4 includes a first aluminum busbar 6, a reinforcing steel plate 7, an insulating plate 8, and a second aluminum busbar 9 stacked sequentially. The size of the busbar 4 is related to the operating voltage / current of the current-limiting reactor. For example, when using a 500kV / 5000A hollow current-limiting reactor, the busbar 4 has a standard size of 234×20 (2*10 double-row) mm. Compared to the original busbar 4 size of 254×19 (1*19 single-row) mm, its loss can be reduced to one-third of the original under the same current, and the temperature rise can be reduced by 60%. The first aluminum busbar 6 and the second aluminum busbar 9 are connected by stainless steel bolts to form a whole. The stainless steel bolts are fitted with insulating sleeves to prevent current from being conducted through the stainless steel bolts.

[0032] Furthermore, the insulating board 8 and the insulating sleeve are made of FR-4 material. The thickness of the insulating board 8 is not less than 10mm, thereby completely separating the first aluminum busbar 6 and the second aluminum busbar 9.

[0033] At the same time, the dimensions of the central shaft 1 will also be adjusted accordingly, that is, the thickness is set to 12mm and the inner radius is 150mm. The bus slot needs to be machined on the central shaft 1 according to the specific design. In order to ensure the firmness of the welding, all welding heights must not be less than 10mm.

[0034] At least two star-shaped arms 10 are plugged and welded to the central shaft 1 through slots in the star-shaped arms 10; the lifting arm 3, the busbar arm 4, and the star-shaped arms 10 are provided with connectors 12 that match the array. These connectors 12 can be three protruding connecting pieces, which serve to make the aforementioned three vertically arranged rings form a whole;

[0035] In a preferred embodiment, the axial groove 2 includes evenly spaced lifting slots, one manifold, and star-shaped arm slots. For example, there are a total of 12 axial grooves 2, including 6 lifting slots, 1 manifold, and 5 star-shaped arm slots. Therefore, the star-shaped frame uses 6 lifting arms 3, 1 manifold 4, and 5 star-shaped arms 10 matched to the aforementioned axial groove 2.

[0036] At least six sets of star-shaped frame reinforcing plates 11 are used to sequentially fix the lifting arm 3, the confluence arm 4, and the star-shaped arm 10 around the central axis 1. The reinforcing plates of the star-shaped arm 10 are made of epoxy board, so that the star-shaped frame can be evenly stressed during hoisting, thereby avoiding damage during transportation or hoisting.

[0037] The lifting boom 3, the confluence boom 4, and the star-shaped boom 10 are all fixed with mounting angle plates 13.

[0038] Furthermore, based on the aforementioned star-shaped structure, the operating mode of this current-limiting reactor will also be adjusted, specifically:

[0039] The 5000A current is divided into two parts, which are connected to the corresponding wires through the left and right halves respectively, and each wire also conducts a portion of the current.

[0040] When a star-shaped support is placed under an alternating magnetic field, it will cut the magnetic field in both the axial and radial directions, generating eddy currents. The eddy current loss is closely related to the size, conductivity, and magnetic field frequency of the star-shaped support, as shown in the following formula:

[0041]

[0042] Where a, b, l, These are the star-shaped frame's thickness, width, length, and conductivity. This represents the axial and radial magnetic field strength of the star-shaped support at a specific point in space. This is because, for most of the time, the star arm 10 is located in a given spatial position. Given a fixed width, length, and material of the star-shaped reactor top plate, based on experience, the relationship between the loss of the star-shaped reactor top plate and its thickness in a large-capacity reactor is approximately as follows:

[0043]

[0044] in The star frame loss when the thickness is 1 can be calculated using equation (1), where K is the structural coefficient. Under normal structural conditions, K ≈ 2.5~2.8 based on experience. From equation (2), it can be seen that when the star frame thickness is doubled, 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 star frame thickness should be as small as possible, generally not exceeding 13mm, and 10mm thickness is recommended as the preferred option.

[0045] This utility model proposes a star-shaped frame for bridge arm reactors and current-limiting reactors. By making the busbar into two layers of aluminum bars and setting a busbar reinforcement steel plate and an insulating plate in the middle, the current is diverted. This reduces the conductive cross-section and avoids abnormal temperature rise. It also allows for stable hoisting, thus ensuring the stable use of the star-shaped frame.

[0046] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

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

2. The star-shaped frame for bridge arm reactors and current-limiting reactors as described in claim 1, characterized in that: The central axis (1) includes 6 independent semicircular axes; the semicircular axes are arranged in a 3*2 array.

3. The star-shaped frame for bridge arm reactors and current-limiting reactors as described in claim 2, characterized in that: The lifting boom (3), the manifold (4), and the star-shaped arm (10) are provided with connectors (12) that match the array.

4. The star-shaped frame for bridge arm reactors and current-limiting reactors as described in claim 1, characterized in that: The axial groove (2) includes a lifting slot, a manifold, and a star-shaped arm slot, all evenly spaced.

5. The star-shaped frame for bridge arm reactors and current-limiting reactors as described in claim 1, characterized in that: The lifting arm (3) is bolted to a reinforcing steel plate, and the lifting arm (3) and the reinforcing steel plate are provided with a through lifting hole.

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

7. The star-shaped frame for bridge arm reactors and current-limiting reactors as described in claim 1, characterized in that, The first aluminum busbar (6), the busbar arm reinforcing steel plate (7), the insulating plate (8) and the second aluminum busbar (9) are connected by stainless steel bolts.

8. The star-shaped frame for bridge arm reactors and current-limiting reactors according to claim 7, characterized in that, The stainless steel bolt is fitted with an insulating sleeve.

9. The star-shaped frame for bridge arm reactors and current-limiting reactors according to claim 8, characterized in that, The insulating board (8) and the insulating sleeve are made of FR-4 material.

Images