An optimized electric field structure for a 12kV medium-voltage environmentally friendly gas C-GIS switchgear

Abstract

This invention discloses an optimized electric field structure for a 12kV medium-voltage environmentally friendly gas C-GIS switchgear, comprising a switchgear busbar compartment, a three-position switch housed therein, three equally spaced incoming and outgoing bushings, and connected three-phase busbars. Specifically: the C-phase busbar is sequentially connected by a first lower vertical section, a first inclined section tilting to the left, and a first left horizontal section; the B-phase busbar is directly connected by a second lower vertical section to a second left horizontal section; the A-phase busbar is sequentially connected by a third lower vertical section, a second inclined section tilting to the right, and a first right horizontal section; the radius of curvature of the edge rounded corners of the horizontal sections of each phase busbar is 20mm; the bending angle between the inclined and horizontal sections of phase A is 130°, phase C is 140°, and the bending angle between the lower vertical and horizontal sections of phase B is 90°; the spacing between the three-phase busbars is 90mm. This invention can reduce the maximum electric field intensity in the busbar compartment, achieve a uniform electric field distribution, prevent partial discharge, and significantly improve the insulation reliability and safety of the switchgear.

Description

Technical Field

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

[0002] Currently, with increasingly stringent environmental protection requirements for power systems, traditional sulfur hexafluoride (SF6) is becoming increasingly important. Gas-insulated switchgear is gradually being restricted due to the greenhouse effect and environmental pollution. Dry air, as an environmentally friendly insulating medium, is widely used in medium-voltage switchgear, but its insulation strength is relatively low, and the electric field concentration phenomenon is more obvious, which can easily cause partial discharge and insulation breakdown, thus affecting the reliability and safety of the switchgear.

[0003] In existing 12kV dry air-insulated switchgear, the busbar compartment often suffers from problems such as electric field concentration and excessively high local electric field strength due to limitations in structural design and arrangement. This is particularly pronounced at busbar bends and corner areas, where potential concentration is severe and can easily trigger corona discharge, affecting the insulation performance and service life of the equipment. Therefore, there is an urgent need for an optimized design scheme that can effectively improve the electric field distribution and reduce local electric field strength to enhance the insulation reliability and safety of medium-voltage environmentally friendly gas C-GIS switchgear. Summary of the Invention

[0004] The purpose of this invention is to solve the problems in the existing technology. Specifically, in existing 12kV dry air-insulated switchgear, the electric field concentration in the busbar compartment and the excessively high local electric field strength, especially at busbar bends and corner areas, are severe, easily leading to corona discharge and affecting the insulation performance and service life of the equipment. This invention proposes a novel electric field optimization structure for 12kV medium-voltage environmentally friendly gas C-GIS (Cubicle-type Gas-Insulated Switchgear) switchgear. This optimized design effectively improves the electric field distribution and reduces local electric field strength in the 12kV medium-voltage environmentally friendly gas C-GIS switchgear, thereby enhancing the insulation reliability and safety of the switchgear. This invention studies the effects of two different methods—the radius of curvature of the busbar edge fillet and the bending angle of the busbar—on the electric field distribution in the busbar compartment of the switchgear. It obtains the optimal fillet curvature and optimal bending angle of the busbar edge, and based on this, optimizes and improves the structural design of the busbar compartment. This significantly reduces the maximum electric field intensity in the switchgear busbar compartment, improves the potential concentration problem, and makes the electric field more uniform at the busbar bends and edges, thereby enhancing the insulation reliability of the switchgear busbar compartment and even the entire medium-voltage environmentally friendly gas C-GIS switchgear.

[0005] To achieve the above objectives, this invention proposes an electric field optimization structure for a 12kV medium-voltage environmentally friendly gas C-GIS switchgear, including...

[0006] switchgear busbar compartment

[0007] The three-position switch is located in the busbar compartment of the switch cabinet.

[0008] Three incoming and outgoing bushings are located in the busbar compartment of the switchgear.

[0009] The three busbars include a C-phase busbar connected at one end to a three-position switch and at the other end to the leftmost inlet / outlet bushing; a B-phase busbar connected at one end to a three-position switch and at the other end to the middle inlet / outlet bushing; and an A-phase busbar connected at one end to a three-position switch and at the other end to the rightmost inlet / outlet 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 tilted to the left, and a first left horizontal section connected to the first inclined section and the leftmost inlet / outlet bushing. The B-phase busbar includes a second lower vertical section connected to the three-position switch and a second left horizontal section connected to the second lower vertical section and the middle inlet / outlet 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 tilted to the right, and a first right horizontal section connected to the second inclined section and the rightmost inlet / outlet bushing.

[0010] The first left horizontal segment, the second left horizontal segment, and the first right horizontal segment constitute the busbar edge rounded corner optimization part. The radius of curvature of the rounded corner of the horizontal segment edge connecting each phase busbar to the incoming and outgoing line bushing is 20mm.

[0011] The angled bends between the first inclined segment and the first lower vertical segment and the first left horizontal segment, the angled bends between the second lower vertical segment and the second left horizontal segment, and the angled bends between the second inclined segment and the third lower vertical segment and the first right horizontal segment constitute the busbar bending angle optimization part: In the A-phase busbar, the bending angle between the inclined segment and the horizontal segment is 130°; in the C-phase busbar, the bending angle between the inclined segment and the horizontal segment is 140°; in the B-phase busbar, the bending angle between the lower vertical segment and the horizontal segment is 90°.

[0012] As a preferred embodiment, the first left horizontal segment, the second left horizontal segment, and the first right horizontal segment constitute the optimized part of the busbar edge rounded corner, and its radius of curvature is optimized from the original 15mm to 20mm.

[0013] Preferably, the angled bends between the first inclined segment and the first lower vertical segment and the first left horizontal segment, the angled bends between the second lower vertical segment and the second left horizontal segment, and the angled bends between the second inclined segment and the third lower vertical segment and the first right horizontal segment constitute the optimized part of the busbar bend angle.

[0014] Preferably, the angle between the first inclined section of the C-phase busbar and the first left horizontal section is reduced from 165° to 140°, the angle between the second lower vertical section of the B-phase busbar and the second left horizontal section is almost 90°, and the angle between the second inclined section of the A-phase busbar and the first right horizontal section is reduced from 150° to 130°.

[0015] Preferably, the first inclined section and the second inclined section form an optimized part of the busbar arrangement, and the arrangement between them is optimized with the change of the above-mentioned busbar bending angle.

[0016] 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 of 60×12 mm.

[0017] 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.

[0018] Advantages of the present invention:

[0019] The optimized part of the busbar edge fillet conducts electric field distribution simulations at different curvature radii at the busbar edge fillet, and obtains the variation law of the maximum electric field intensity in the busbar chamber with the curvature radius of the busbar edge fillet. As the rounded corner becomes larger, the maximum electric field intensity in the busbar chamber gradually becomes smaller, and the maximum electric field intensity at the busbar edge as a whole shows a downward trend. It can be seen from the attached drawings that when using a busbar with R15, the maximum electric field intensity in the busbar chamber and the maximum electric field intensity at the busbar edge will both increase, and the electric potential at the busbar edge is concentrated and very uneven, which is not advisable. From the trend of the graph line, when 5<R<20, the overall maximum electric field intensity and the maximum electric field intensity at the bending part gradually decrease. In addition, considering the connection between the busbar and the contact seat, in order to ensure the connection strength and the minimum contact resistance, the R25 busbar 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. Simulations of the electric field distribution in the busbar chamber before and after the fillet optimization show that the maximum electric field intensity in the busbar chamber drops from 4.09 kV / mm to 3.77 kV / mm, with an overall decrease of 7.8%.

[0020] The optimized part of the busbar bending angle conducts electric field distribution simulations at different bending angles at the busbar bending part, and obtains the variation law of the maximum electric field intensity of the busbar with the angle at the busbar bending part. As the angle at the busbar bending part becomes larger, the maximum electric field intensity of the busbar as a whole shows a trend of first increasing and then decreasing. It can be seen from the attached drawings that when using / The electric field strength increases at both the busbar and its edges, resulting in a concentrated and uneven electric field at the busbar edges, which is undesirable. As can be seen from the graph, when... At that time, the maximum electric field strength of phase A busbar and the maximum electric field strength at the bend gradually decrease. The maximum electric field strength at the bend and at the flexure gradually increase. At this time, 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, the following is excluded: Mother row; when At that time, the maximum electric field strength of the C-phase busbar and the maximum electric field strength at the bend gradually decrease. The maximum electric field strength at the bend and at the flexure gradually increase. At this time, 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, the following is excluded: Busbars; Furthermore, due to the small lateral extension distance of phase B in the 12kV medium-voltage environmentally friendly gas C-GIS switchgear, optimizing it would lead to significant changes in the connection strength and contact resistance of the busbars and incoming bushings, so its structure remains unchanged. Therefore, considering the actual manufacturing cost and specific manufacturing process requirements, the angle of the A-phase busbar bend was optimized from 150° to 130°, and the angle of the C-phase busbar bend was optimized from 165° to 140°. Phase B's electric field distribution was optimized through structural optimization of other parts. This optimization reduces the electric field strength at the busbar bends, preventing potential concentration and partial discharge. Additionally, the change in busbar bend angle optimizes the busbar arrangement; by adjusting the spatial arrangement and distance of the busbars, the electric field gradient is smoothed, and the electric field distribution is more uniform. Simulations of the indoor electric field distribution of the busbars before and after optimization at the busbar bends show that the maximum electric field strength of phases A, B, and C of the busbar decreased by 17.18%, 14.12%, and 11.47%, respectively.

[0021] This invention significantly improves the electric field concentration problem by optimizing the structure of the switchgear busbar compartment. Electric field simulations of the models before and after optimization show that the maximum electric field strength inside the busbar compartment decreased from 4.51 kV / mm to 3.76 kV / mm, an overall reduction of 16.63%. This improves the insulation reliability and safety of the 12kV medium-voltage environmentally friendly gas C-GIS switchgear, making it widely applicable in medium-voltage power distribution systems and possessing strong engineering application value. Through optimized design of the busbar edge radius, bend size, and busbar layout, the invention effectively reduces charge accumulation caused by the tip effect under lightning impulse voltage, thereby reducing the local electric field gradient and fundamentally improving the electric field distribution of the 12kV medium-voltage environmentally friendly gas C-GIS switchgear, significantly enhancing insulation reliability and safety, and demonstrating broad engineering application prospects.

[0022] The features and advantages of the present invention will be described in detail through embodiments and in conjunction with the accompanying drawings. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the electric field optimization structure of a 12kV medium-voltage environmentally friendly gas C-GIS switchgear according to the present invention;

[0024] Figure 2 This is a curve showing the variation of the maximum electric field intensity of the busbar compartment with the radius of curvature of the busbar edge fillet in the electric field optimization structure of a 12kV medium-voltage environmentally friendly gas C-GIS switchgear according to the present invention.

[0025] Figure 3 This is a curve showing the variation of the maximum electric field strength of the busbar with the bending angle of the electric field optimization structure of a 12kV medium-voltage environmentally friendly gas C-GIS switchgear according to the present invention.

[0026] Figure 4 This is a comparison diagram of the overall electric field simulation results of the busbar compartment before and after the optimization of the electric field optimization structure of a 12kV medium-voltage environmentally friendly gas C-GIS switchgear according to the present invention.

[0027] Figure 2 In the figure, the horizontal axis represents the fillet radius R / mm, and the vertical axis represents the maximum electric field strength kV / mm. Figure 3 In the middle, the horizontal axis represents the corner. / degree, the left figure shows the maximum electric field intensity of phase A in kv / mm, and the right figure shows the maximum electric field intensity of phase C in kv / mm. Detailed Implementation

[0028] See Figure 1 , Figure 2 , Figure 3 and Figure 4The present invention includes a switch cabinet busbar compartment 1, a three-position switch 14 disposed in the busbar compartment, three equally spaced incoming and outgoing bushings 15, and a three-phase busbar connecting the three-position switch 14 and the incoming and outgoing bushings 15.

[0029] The three-phase busbar includes: a C-phase busbar connected at one end to the three-position switch 14 and at the other end to the leftmost inlet / outlet bushing 15; a B-phase busbar connected at one end to the three-position switch 14 and at the other end to the middle inlet / outlet bushing 15; and an A-phase busbar connected at one end to the three-position switch 14 and at the other end to the rightmost inlet / outlet bushing 15. The C-phase busbar consists 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 tilted to the left, and a first left horizontal section connected to the first inclined section and the leftmost inlet / outlet bushing 15. The B-phase busbar consists 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 / outlet bushing 15. The A-phase busbar consists 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 tilted to the right, and a first right horizontal section connected to the second inclined section and the rightmost inlet / outlet bushing 15.

[0030] The first left horizontal segment, the second left horizontal segment, and the first right horizontal segment constitute the busbar edge rounded corner optimization part. The radius of curvature of the rounded corner of the horizontal segment connecting each phase busbar to the inlet / outlet bushing 15 is 20mm.

[0031] The angled bends between the first inclined segment and the first lower vertical segment and the first left horizontal segment, the angled bends between the second lower vertical segment and the second left horizontal segment, and the angled bends between the second inclined segment and the third lower vertical segment and the first right horizontal segment constitute the busbar bending angle optimization part: In the A-phase busbar, the bending angle between the inclined segment and the horizontal segment is 130°; in the C-phase busbar, the bending angle between the inclined segment and the horizontal segment is 140°; in the B-phase busbar, the bending angle between the lower vertical segment and the horizontal segment is 90°.

[0032] Working process of this invention:

[0033] The electric field optimization structure of a 12kV medium-voltage environmentally friendly gas C-GIS switchgear of the present invention is described in conjunction with the accompanying drawings during operation.

[0034] In a 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 radius of curvature is optimized from the original 15mm to 20mm.

[0035] In the preferred embodiment of the optimized structure of the 12 kV medium-voltage environmentally friendly gas C-GIS switchgear, the bending corners at the angles between the first inclined section and the first lower vertical section and 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 and the first right horizontal section form the optimized part 12 of the busbar bending angle. Among them, the angle between the first 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 left horizontal section of the B-phase busbar is almost 90°, and the angle between the second inclined section and the first right horizontal section of the A-phase busbar is reduced from the original 150° to 130°.

[0036] In the preferred embodiment of the optimized structure of the 12 kV medium-voltage environmentally friendly gas C-GIS switchgear, the first inclined section and the second inclined section form the optimized part 13 of the busbar arrangement, and their arrangement between each other is optimized with the change of the above-mentioned busbar bending angle.

[0037] In the preferred embodiment of the optimized structure of the 12 kV medium-voltage environmentally friendly gas C-GIS switchgear, three incoming and outgoing line bushings 15 are arranged at equal intervals in the switchgear busbar chamber 1.

[0038] 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 a downward trend as a whole; when 5 < R < 20, the overall maximum electric field strength and the maximum electric field strength at the bending part gradually decrease.

[0039] 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 as a whole. 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 [[ID=二十一]] [[ID=二十二]]..., the maximum electric field strength and the maximum electric field strength at the bending part gradually decrease; when [[ID=二十三]] [[ID=二十四]]..., the maximum electric field strength of the C-phase busbar and the maximum electric field strength at the bending part gradually decrease, when [[ID=二十五]] [[ID=二十六]]..., the maximum electric field strength and the maximum electric field strength at the bending part gradually increase, when [[ID=二十七]] [[ID=二十八]]..., the maximum electric field strength and the maximum electric field strength at the bending part gradually decrease. [[ID=二十九]] [[ID=三十]]

[0040] [[ID=三十一]]As [[ID=三十二]] Figure 4As shown, the electric field distribution of the busbar compartment of the 12kV medium-voltage environmentally friendly gas C-GIS switchgear before and after electric field optimization was simulated. The results show that the structural electric field strength of the busbar is reduced after optimization, and the uniformity of the electric field in the entire busbar compartment is significantly improved. The maximum electric field strength in the busbar compartment decreased from 4.51kV / mm to 3.76kV / mm. The results indicate that the optimized structure has higher insulation reliability and safety.

[0041] The above embodiments are illustrative of the present invention and are not intended to limit the present invention. Any simple modifications to the present invention are within the scope of protection of the present invention.

Claims

1. An electric field optimization structure for a 12kV medium-voltage environmentally friendly gas C-GIS switchgear, characterized in that: It includes a switch cabinet busbar compartment (1), a three-position switch (14) located in the busbar compartment, three equally spaced incoming and outgoing bushings (15), and a three-phase busbar connecting the three-position switch (14) and the incoming and outgoing bushings (15); The three-phase busbar includes: a C-phase busbar with one end connected to a three-position switch (14) and the other end connected to the leftmost inlet / outlet bushing (15); a B-phase busbar with one end connected to a three-position switch (14) and the other end connected to the middle inlet / outlet bushing (15); and an A-phase busbar with one end connected to a three-position switch (14) and the other end connected to the rightmost inlet / outlet bushing (15). The C-phase busbar consists of a first lower vertical section connecting the three-position switch (14), a first inclined section connecting the first lower vertical section and tilting to the left, and a first left horizontal section connecting the first inclined section and the leftmost inlet / outlet bushing (15); the B-phase busbar consists of a second lower vertical section connecting the three-position switch (14), and a second left horizontal section directly connecting the second lower vertical section and the middle inlet / outlet bushing (15); the A-phase busbar consists of a third lower vertical section connecting the three-position switch (14), a second inclined section connecting the third lower vertical section and tilting to the right, and a first right horizontal section connecting the second inclined section and the rightmost inlet / outlet bushing (15). The first left horizontal segment, the second left horizontal segment, and the first right horizontal segment constitute the optimized part of the busbar edge rounded corners; The angle bend between the first inclined segment and the first lower vertical segment and the first left horizontal segment, the angle bend between the second lower vertical segment and the second left horizontal segment, and the angle bend between the second inclined segment and the third lower vertical segment and the first right horizontal segment constitute the part of the busbar bending angle optimization.

2. The electric field optimization structure of a 12kV medium-voltage environmentally friendly gas C-GIS switchgear according to claim 1, characterized in that: In the optimized section of the busbar edge rounding, the radius of curvature of the rounding of the horizontal section edge connecting each phase busbar with the incoming and outgoing bushing (15) is 20mm.

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

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

5. The electric field optimization structure of a 12kV medium-voltage environmentally friendly gas C-GIS switchgear according to claim 1, characterized in that: The three-phase busbars are arranged at equal intervals in the busbar compartment (1) of the switchgear, with an adjacent busbar spacing of 90mm.

6. The electric field optimization structure of a 12kV medium-voltage environmentally friendly gas C-GIS switchgear according to claim 1, characterized in that: 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 a 12kV medium-voltage environmentally friendly gas C-GIS switchgear according to claim 1, characterized in that: The spatial arrangement of the first and second inclined segments achieves uniform electric field distribution through optimization of the bending angle.

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