Electric field optimization structure of novel 12kV medium-voltage environment-friendly gas C-GIS switch cabinet

Abstract

The invention discloses an electric field optimization structure of a novel 12kV medium-voltage environment-friendly gas C-GIS switch cabinet. The electric field optimization structure comprises a switch cabinet bus chamber, a three-position switch arranged in the switch cabinet bus chamber, three inlet and outlet wire sleeves arranged at equal intervals, and a connected three-phase bus. Wherein the C-phase bus is formed by sequentially connecting a first lower vertical section, a first inclined section inclined leftwards and a first left horizontal section; the B-phase bus is directly connected with a second left horizontal section through a second lower vertical section; the A-phase bus is formed by sequentially connecting a third lower vertical section, a second inclined section inclined rightwards and a first right horizontal section; the curvature radius of the edge fillet of the horizontal section of each phase bus is 20mm, the bending angle between the A-phase inclined section and the horizontal section is 130 degrees, the bending angle between the C-phase inclined section and the horizontal section is 140 degrees, the bending angle between the B-phase lower vertical section and the horizontal section is 90 degrees, and the distance between the three phases of buses is 90mm. The maximum electric field intensity of the bus chamber can be reduced, electric field distribution is uniform, partial discharge is prevented, and the insulation reliability and safety of the switch cabinet are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power distribution equipment, in particular to the technical field of an electric field optimization structure of a novel 12kV medium-voltage environmentally friendly gas C-GIS switchgear. Background Art

[0002] At present, with the increasingly stringent environmental protection requirements of power systems, traditional sulfur hexafluoride ( Gas-insulated switchgear is increasingly being restricted due to its greenhouse effect and environmental pollution. Dry air, as an environmentally friendly insulating medium, is widely used in medium-voltage switchgear. However, its dielectric strength is relatively low, leading to more pronounced electric field concentration, which can easily cause partial discharge and insulation breakdown, thus impacting the reliability and safety of the switchgear.

[0003] In existing 12kV dry air insulated switchgear, the busbar compartment often experiences problems such as electric field concentration and excessively high local field strength due to structural design and arrangement limitations. This is particularly true at busbar bends and corners, where potential concentration is severe, easily inducing corona discharge and impacting the insulation performance and service life of the equipment. Therefore, an optimized design solution is urgently needed to effectively improve electric field distribution and reduce local field strength, thereby enhancing the insulation reliability and safety of medium-voltage environmentally friendly gas C-GIS switchgear. Summary of the Invention

[0004] The purpose of the present invention is to solve the problems in the prior art. In response to the problems of concentrated electric fields and excessively high local field strengths in the busbar compartment of existing 12kV dry air insulated switchgear, particularly at busbar bends and corners, the potential concentration is severe, which easily triggers corona discharge and affects the insulation performance and service life of the equipment. This invention proposes an electric field optimization structure for a new 12kV medium-voltage environmentally friendly gas C-GIS (Cubicle-type Gas-Insulated Switchgear) switchgear. This design effectively improves the electric field distribution and reduces the local field strength of the 12kV medium-voltage environmentally friendly gas C-GIS switchgear, thereby improving the insulation reliability and safety of the medium-voltage environmentally friendly gas C-GIS switchgear. The present invention studies the influence of two different methods, namely the busbar edge fillet curvature radius and the busbar bending angle, on the electric field distribution in the switchgear busbar chamber, and obtains the optimal busbar edge fillet curvature and the optimal bending angle. Based on this, the structural design of the busbar chamber is optimized and improved, which significantly reduces the maximum electric field strength of the switchgear busbar chamber, improves the potential concentration problem, and makes the electric field at the busbar bending and edge more uniform, thereby improving the insulation reliability of the switchgear busbar chamber and even the entire medium-voltage environmentally friendly gas C-GIS switchgear.

[0005] To achieve the above objectives, the present invention proposes a new type of 12kV medium voltage environmentally friendly gas C-GIS switchgear electric field optimization structure, including Switchgear busbar room, The three-position switch is installed in the busbar room of the switch cabinet. Three inlet and outlet bushings are installed in the busbar room of the switch cabinet. Three busbars, including a C-phase busbar having one end connected to a three-position switch and the other end connected to the leftmost incoming and outgoing line bushing, a B-phase busbar having one end connected to the three-position switch and the other end connected to the middle incoming and outgoing line bushing, and an A-phase busbar having one end connected to the three-position switch and the other end connected to the rightmost incoming and outgoing line bushing. The C-phase busbar includes a first lower vertical section connected to the three-position switch, a first inclined section connected to the first lower vertical section and inclined to the left, and a first left horizontal section connecting the first inclined section and the leftmost incoming and outgoing line bushing. The B-phase busbar includes a second lower vertical section connected to the three-position switch, a second left horizontal section connected to the second lower vertical section and the middle incoming and outgoing line bushing. The A-phase busbar includes a third lower vertical section connected to the three-position switch, a second inclined section connected to the third lower vertical section and inclined to the right, and a first right horizontal section connecting the second inclined section and the rightmost incoming and outgoing line bushing. The first left horizontal section, the second left horizontal section and the first right horizontal section constitute the busbar edge fillet optimization part, and the fillet curvature radius of the horizontal section edge where each phase busbar is connected to the incoming and outgoing line bushings is 20mm; The angle bending part between the first inclined section and the first lower vertical section and the first left horizontal section, the angle bending part between the second lower vertical section and the second left horizontal section, and the angle bending part between the second inclined section and the third lower vertical section and the first right horizontal section constitute the busbar bending angle optimization part: in the A-phase busbar, the bending angle between the inclined section and the horizontal section is 130°; in the C-phase busbar, the bending angle between the inclined section and the horizontal section is 140°; in the B-phase busbar, the bending angle between the lower vertical section and the horizontal section is 90°.

[0006] Preferably, the first left horizontal segment, the second left horizontal segment and the first right horizontal segment constitute a busbar edge fillet optimization portion, and the curvature radius thereof is optimized from the original 15 mm to 20 mm.

[0007] Preferably, the angle bend between the first inclined section and the first lower vertical section, the first left horizontal section, the angle bend between the second lower vertical section and the second left horizontal section, and the angle bend between the second inclined section and the third lower vertical section, the first right horizontal section constitute the busbar bending angle optimization part.

[0008] Preferably, the angle between the first left inclined section and the first left horizontal section of the C-phase busbar is reduced from the original 165° to 140°, the angle between the second lower vertical section and the second right horizontal section of the B-phase busbar is nearly 90°, and the angle between the third right inclined section and the third right horizontal section of the A-phase busbar is reduced from the original 150° to 130°.

[0009] Preferably, the first inclined section, the second inclined section and the third inclined section form an optimized part of the busbar arrangement, and the arrangement mode between them is optimized with the change of the above-mentioned busbar bending angle.

[0010] Preferably, the busbar chamber of the switchgear is the busbar chamber of a 12kV / 1250A dry air-insulated C-GIS switchgear, and the busbar specification is a rectangular copper busbar with a size of 60×12 mm.

[0011] Preferably, the three-phase busbars are arranged at equal intervals in the busbar chamber of the switchgear, and the distance between each two is 90mm.

[0012] Advantages of the present invention: The busbar edge fillet optimization part obtained the variation law of the maximum electric field strength in the busbar chamber with the curvature radius of the busbar edge fillet through the simulation of the electric field distribution at different curvature radii at the busbar edge fillet. As the rounded corner becomes larger, the maximum electric field strength in the busbar chamber gradually becomes smaller, and the maximum electric field strength at the edge of the busbar row as a whole shows a downward trend. As can be seen from the attached drawings, when using a busbar row with R15, the maximum electric field strength in the busbar chamber and the maximum electric field strength at the edge of the busbar will both increase, and the electric potential at the edge of the busbar row is concentrated and very uneven, which is not advisable. From the trend of the graph, when 5 < R < 20, the overall maximum electric field strength and the maximum electric field strength at the bending part gradually decrease. In addition, considering the connection between the busbar row and the contact seat, in order to ensure the connection strength and the minimum contact resistance, the busbar row with R25 is excluded. Therefore, considering the actual manufacturing cost and the specific requirements of the manufacturing process, the curvature radius of the busbar edge fillet is optimized from 15mm to 20mm. By increasing the curvature radius of the fillet, the charge accumulation caused by the tip effect can be effectively reduced, and the electric field distribution in the busbar chamber can be made more uniform. The simulation of the electric field distribution in the busbar chamber before and after the fillet optimization shows that the maximum electric field strength in the busbar chamber drops from 4.09 kV / mm to 3.77 kV / mm, with an overall decrease of 7.8%.

[0013] The busbar bending angle optimization part obtained the variation law of the maximum electric field strength of the busbar with the angle at the busbar bending part through the simulation of the electric field distribution at different bending angles at the busbar bending part. As the angle at the busbar bending part becomes larger, the maximum electric field strength of the busbar as a whole shows a trend of first increasing and then decreasing. As can be seen from the attached drawings, when using / [[ID=ID=20]] The busbar, the maximum field strength of the busbar and the maximum field strength at the busbar edge will become larger, and the electric field at the busbar edge will be concentrated, which is very uneven and undesirable. When the maximum electric field intensity of the A-phase busbar and the maximum electric field intensity at the bend gradually decrease, The maximum electric field intensity and the maximum electric field intensity at the bend gradually increase. When the maximum electric field strength and the maximum electric field strength at the bend gradually decrease, in addition, considering the connection between the busbar and the incoming bushing, in order to ensure the connection strength and minimum contact resistance, exclude Busbar; when When the maximum electric field intensity of the C-phase busbar and the maximum electric field intensity at the bend gradually decrease, The maximum electric field intensity and the maximum electric field intensity at the bend gradually increase. When the maximum electric field strength and the maximum electric field strength at the bend gradually decrease, in addition, considering the connection between the busbar and the incoming bushing, in order to ensure the connection strength and minimum contact resistance, exclude Furthermore, since the lateral extension of phase B of the 12kV medium-voltage environmentally friendly gas C-GIS switchgear is relatively short, optimizing it would result in significant changes in the connection strength and contact resistance between the busbar and the incoming bushing, so the structure remained unchanged. Therefore, considering actual production costs and specific manufacturing process requirements, the angle of the busbar bend on phase A was optimized from 150° to 130°, and the angle of the busbar bend on phase C was optimized from 165° to 140°. The electric field distribution on phase B was optimized through structural optimization of other components. This optimization reduces the electric field intensity at the busbar bend, preventing potential concentration and partial discharge. Furthermore, the change in busbar bend angle optimizes the busbar layout. By adjusting the spatial arrangement and spacing of the busbars, the electric field gradient is smoothed, resulting in a more uniform electric field distribution. Simulations of the electric field distribution within the busbar compartment before and after the busbar bend optimization revealed reductions of 17.18%, 14.12%, and 11.47% in the maximum field intensity for busbar phases A, B, and C, respectively.

[0014] The present invention significantly improves the problem of electric field concentration by optimizing the busbar chamber structure of the switch cabinet. Electric field simulation of the models before and after optimization shows that the maximum electric field strength in the busbar chamber drops from 4.51 kV / mm to 3.76 kV / mm, with an overall reduction of 16.63%. This improves the insulation reliability and safety of the 12 kV medium-voltage environmentally friendly gas C-GIS switch cabinet, and can be widely used in medium-voltage power distribution systems. It has strong engineering application value. By optimizing the busbar edge fillet radius, the corner size of the bend, and the busbar arrangement, it effectively reduces the charge accumulation caused by the tip effect under lightning impulse voltage, thereby reducing the local electric field gradient, fundamentally improving the electric field distribution of the 12 kV medium-voltage environmentally friendly gas C-GIS switch cabinet, significantly improving the insulation reliability and safety, and has broad engineering application prospects.

[0015] The features and advantages of the present invention will be described in detail through embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the electric field optimization structure of a novel 12kV medium-voltage environmentally friendly gas C-GIS switchgear according to the present invention; Figure 2 This is a curve diagram showing the variation of the maximum electric field intensity in the busbar compartment of the electric field optimization structure of a novel 12kV medium-voltage environmentally friendly gas C-GIS switchgear according to the present invention with the radius of curvature of the busbar edge fillet; Figure 3 This is a curve diagram showing the change of the busbar maximum electric field intensity with the busbar bending angle in the electric field optimization structure of a novel 12kV medium-voltage environmentally friendly gas C-GIS switchgear according to the present invention; Figure 4 This is a comparison chart of the overall electric field simulation results of the busbar chamber before and after optimization of the electric field optimization structure of a new type of 12kV medium-voltage environmentally friendly gas C-GIS switchgear of the present invention.

[0017] Figure 2 In the figure, the horizontal axis is the roundness R / mm, and the vertical axis is the maximum electric field strength kv / mm. Figure 3 In the figure, the horizontal axis is the corner / degree, the vertical axis of the left figure is the maximum electric field strength of phase A kv / mm, and the vertical axis of the right figure is the maximum electric field strength of phase C kv / mm. DETAILED DESCRIPTION

[0018] See Figure 1 、 Figure 2 、 Figure 3 and Figure 4 The present invention comprises a switch cabinet busbar chamber 1, a three-position switch 14 arranged in the busbar chamber, three equally spaced incoming and outgoing line bushings 15, and a three-phase busbar connecting the three-position switch 14 and the incoming and outgoing line bushings 15; The three-phase busbar includes: a C-phase busbar having one end connected to the three-position switch 14 and the other end connected to the leftmost incoming and outgoing line bushing 15; a B-phase busbar having one end connected to the three-position switch 14 and the other end connected to the middle incoming and outgoing line bushing 15; and an A-phase busbar having one end connected to the three-position switch 14 and the other end connected to the rightmost incoming and outgoing line bushing 15. The C-phase busbar is composed of a first lower vertical section connected to the three-position switch 14, a first inclined section connected to the first lower vertical section and inclined to the left, and a first left horizontal section connecting the first inclined section and the leftmost incoming and outgoing line bushing 15; the B-phase busbar is composed of a second lower vertical section connected to the three-position switch 14 and a second left horizontal section directly connecting the second lower vertical section and the middle incoming and outgoing line bushing 15; and the A-phase busbar is composed of a third lower vertical section connected to the three-position switch 14, a second inclined section connected to the third lower vertical section and inclined to the right, and a first right horizontal section connecting the second inclined section and the rightmost incoming and outgoing line bushing 15. The first left horizontal section, the second left horizontal section and the first right horizontal section constitute the busbar edge fillet optimization part, and the fillet curvature radius of the horizontal section edge where each phase busbar is connected to the incoming and outgoing line bushings 15 is 20 mm; The angle bending part between the first inclined section and the first lower vertical section and the first left horizontal section, the angle bending part between the second lower vertical section and the second left horizontal section, and the angle bending part between the second inclined section and the third lower vertical section and the first right horizontal section constitute the busbar bending angle optimization part: in the A-phase busbar, the bending angle between the inclined section and the horizontal section is 130°; in the C-phase busbar, the bending angle between the inclined section and the horizontal section is 140°; in the B-phase busbar, the bending angle between the lower vertical section and the horizontal section is 90°.

[0019] Working process of the present invention: The electric field optimization structure of a novel 12kV medium-voltage environmentally friendly gas C-GIS switchgear of the present invention is described in conjunction with the accompanying drawings during operation.

[0020] In the preferred embodiment of the electric field optimization structure of the 12kV medium-voltage environmentally friendly gas C-GIS switchgear, the first left horizontal section, the second left horizontal section and the first right horizontal section constitute the busbar fillet optimization part 11, and its curvature radius is optimized from the original 15mm to 20mm.

[0021] In the preferred embodiment of the optimized structure of the electric field of the 12 kV medium-voltage environmentally friendly gas C-GIS switchgear, the bending angles at the joints between the first inclined section and the first lower vertical section, the first left horizontal section, between the second lower vertical section and the second left horizontal section, and between the second inclined section and the third lower vertical section, the first right horizontal section form the optimized part 12 of the busbar bending angle. Among them, the angle between the first left inclined section and the first left horizontal section of the C-phase busbar is reduced from the original 165° to 140°; the angle between the second lower vertical section and the second right horizontal section of the B-phase busbar is almost 90 degrees; the angle between the third right inclined section and the third right horizontal section of the A-phase busbar is reduced from the original 150° to 130°.

[0022] In the preferred embodiment of the optimized structure of the electric field of the 12 kV medium-voltage environmentally friendly gas C-GIS switchgear, the first inclined section, the second inclined section and the third inclined section form the optimized part 13 of the busbar arrangement, and their arrangement modes between each other are optimized with the change of the above-mentioned busbar bending angle.

[0023] In the preferred embodiment of the optimized structure of the electric field of the 12 kV medium-voltage environmentally friendly gas C-GIS switchgear, the three incoming and outgoing line bushings 15 are arranged at equal intervals in the switchgear busbar chamber 1.

[0024] As Figure 2 shown, the electric field distribution simulation is carried out at different curvature radii at the rounded corners of the busbar edge of the 12 kV medium-voltage environmentally friendly gas C-GIS switchgear. As the rounded corner becomes larger, the overall maximum electric field strength in the busbar chamber gradually becomes smaller, and the maximum electric field strength at the edge of the busbar strip shows an overall downward trend; when 5 < R < 20, the overall maximum electric field strength and the maximum electric field strength at the bending part gradually decrease.

[0025] As Figure 3 shown, the electric field distribution simulation is carried out at different bending angles at the busbar bending part of the 12 kV medium-voltage environmentally friendly gas C-GIS switchgear. As the angle at the busbar bending part becomes larger, the maximum electric field strength of the busbar shows a trend of first increasing and then decreasing overall.From the trend of the graph line, when ..., the maximum electric field strength of the A-phase busbar and the maximum electric field strength at the bending part gradually decrease. When ..., the maximum electric field strength and the maximum electric field strength at the bending part gradually increase. When ..., the maximum electric field strength and the maximum electric field strength at the bending part gradually decrease; when ..., the maximum electric field strength of the C-phase busbar and the maximum electric field strength at the bending part gradually decrease. When ..., the maximum electric field strength and the maximum electric field strength at the bending part gradually increase. When ..., the maximum electric field strength and the maximum electric field strength at the bending part gradually decrease.

[0026] As Figure 4As shown in the figure, the electric field distribution simulation of the busbar chamber as a whole before and after the electric field optimization of the 12kV medium-voltage environmentally friendly gas C-GIS switchgear was carried out. The results show that the structural electric field strength of the busbar is reduced after optimization, and the electric field uniformity of the entire busbar chamber is significantly improved. The maximum electric field strength in the busbar chamber is reduced from 4.51kV / mm to 3.76kV / mm. The results show that the optimized structure has higher insulation reliability and safety.

[0027] The above embodiments are intended to illustrate the present invention, not to limit the present invention. Any solution that is a simple transformation of the present invention falls within the protection scope of the present invention.

Claims

1. A new type of 12kV medium voltage environmentally friendly gas C-GIS switchgear electric field optimization structure, characterized by: It comprises a switch cabinet busbar chamber (1), a three-position switch (14) arranged in the busbar chamber, three inlet and outlet bushings (15) arranged at equal intervals, and a three-phase busbar connecting the three-position switch (14) and the inlet and outlet bushings (15); The three-phase busbar comprises: a C-phase busbar having one end connected to a three-position switch (14) and the other end connected to the leftmost incoming and outgoing line bushing (15); a B-phase busbar having one end connected to a three-position switch (14) and the other end connected to the middle incoming and outgoing line bushing (15); and an A-phase busbar having one end connected to a three-position switch (14) and the other end connected to the rightmost incoming and outgoing line bushing (15); The C-phase busbar is composed of a first lower vertical section connected to the three-position switch (14), a first inclined section connected to the first lower vertical section and inclined to the left, and a first left horizontal section connected to the first inclined section and the leftmost inlet and outlet bushing (15); the B-phase busbar is composed of a second lower vertical section connected to the three-position switch (14), and a second left horizontal section directly connected to the second lower vertical section and the middle inlet and outlet bushing (15); the A-phase busbar is composed of a third lower vertical section connected to the three-position switch (14), a second inclined section connected to the third lower vertical section and inclined to the right, and a first right horizontal section connected to the second inclined section and the rightmost inlet and outlet bushing (15); The first left horizontal segment, the second left horizontal segment and the first right horizontal segment constitute a busbar edge fillet optimization portion; The angle bend between the first inclined section and the first lower vertical section, the first left horizontal section, the angle bend between the second lower vertical section and the second left horizontal section, and the angle bend between the second inclined section and the third lower vertical section, the first right horizontal section constitute the busbar bending angle optimization part.

2. The electric field optimization structure of the novel 12kV medium voltage environmentally friendly gas C-GIS switchgear according to claim 1 is characterized by: In the busbar edge fillet optimization portion, the fillet curvature radius of the horizontal section edge where each phase busbar is connected to the incoming and outgoing line bushings (15) is 20 mm.

3. The electric field optimization structure of the novel 12kV medium voltage environmentally friendly gas C-GIS switchgear according to claim 1 is characterized by: In the busbar bending angle optimization part, in the A-phase busbar, the bending angle between the inclined section and the horizontal section is 130°; in the C-phase busbar, the bending angle between the inclined section and the horizontal section is 140°; in the B-phase busbar, the bending angle between the lower vertical section and the horizontal section is 90°.

4. The electric field optimization structure of the novel 12kV medium voltage environmentally friendly gas C-GIS switchgear according to claim 1 is characterized by: The busbar is a 60×12 mm rectangular copper busbar.

5. The electric field optimization structure of the novel 12kV medium voltage environmentally friendly gas C-GIS switchgear according to claim 1 is characterized by: The three-phase busbars are arranged at equal intervals in the switch cabinet busbar chamber (1), and the distance between adjacent busbars is 90 mm.

6. The electric field optimization structure of the novel 12kV medium voltage environmentally friendly gas C-GIS switchgear according to claim 1 is characterized by: The first inclined section and the first lower vertical section of the C-phase busbar, as well as the second inclined section and the third lower vertical section of the A-phase busbar, are connected by bending.

7. The electric field optimization structure of the novel 12kV medium voltage environmentally friendly gas C-GIS switchgear according to claim 1 is characterized by: The spatial arrangement relationship between the first inclined segment and the second inclined segment achieves uniform electric field distribution by optimizing the bending angle.

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