CN117275975A - Double-break isolating switch with position indication - Google Patents

Abstract

The invention provides a double-break isolating switch with position indication, which comprises a switch body and an operating mechanism, wherein a switch position indication device is arranged on one side of the switch body, an operating mechanism is arranged on the other side of the switch body, and an operating position indication device is arranged at the bottom of the operating mechanism. The invention has the beneficial effects that: the GIS reservation space is designed to meet the requirement of uninterrupted power supply in the whole process of the second-stage extension installation and the field handover test, which is proposed by the national network company. Meanwhile, the device has the advantages of reasonable design structure, stable performance, low manufacturing cost, convenience in installation and safety and reliability in operation.

Description

Double-break isolating switch with position indication

Technical Field

The invention belongs to the technical field of high-voltage switches, and particularly relates to a double-break isolating switch with position indication.

Background

In order to reduce the capital cost and the operation and maintenance cost, the GIS products (GIS is totally called as gas insulated switchgear) are generally built in stages at present. According to eighteen anti-measure file requirements of the national network, for the planned extension interval, the bus isolating switch, the grounding switch and the local working power supply should be completely arranged at one time. Therefore, the extension interface reserved by the first-stage equipment comprises a main bus, a conventional isolating switch, a grounding switch and other equipment, and only one isolating switch is arranged between the extension unit and the operation bus during the second-stage extension, while the isolating switch of the main stream in the current industry is a single-fracture isolating switch which mainly comprises an isolating switch body and an operating mechanism thereof, all charged parts such as a moving contact, a fixed contact and the like of the isolating switch are arranged in a metal shell, and an output shaft of the operating mechanism is connected with the isolating switch body to drive the isolating switch to realize the opening and closing operation of the isolating switch. When the isolating switch is in the opening position, a fracture is formed between the moving contact and the fixed contact, so that internal electrical insulation is realized. However, the single-fracture isolating switch can only realize that a single isolating fracture exists between the butt joint working face and the bus for live operation, and once fracture breakdown occurs from the live operation part to the butt joint part, personal injury can be caused to constructors; therefore, when the conventional reserved interval is expanded at present, the original operation bus is powered off. The power failure of the whole bus of the GIS inevitably leads to the reduction of the power grid quality and the increase of the operation cost, so that the GIS equipment capable of realizing the extension of the reserved interval under the condition of no power failure is provided, and the isolating switch with double fractures can meet the requirement.

Moreover, the 220kV GIS double-break bus isolating switch technology is divided into recommended application type technologies in the annex 2 of the national grid company infrastructure technology [2022]14, the notice of the application catalog of the published infrastructure technology by the national grid infrastructure, and the engineering application of the newly developed design is used in principle. The national grid company's basic construction technical document "general design technical scheme of substation" also requires: a double-break isolating switch is arranged on the side of a 220kV GIS standby interval bus adopting double bus wiring, and uninterrupted extension is realized.

Based on above-mentioned demand this application proposes a double-break isolator to satisfy market's demand.

In addition, in the process of the extension operation of the reserved interval, a complete and reliable isolation fracture must be formed between the butt joint working face and the bus in live operation, and the conventional mode for judging whether the isolation fracture is reliably formed is to observe the opening and closing position indicator of the isolation switch mechanism. When the opening and closing position indicator of the isolating switch mechanism indicates the opening and closing position, the isolating fracture is judged to be formed. However, since the opening and closing position indicator of the mechanism is not directly connected to the isolating switch body, an incorrect indication of the opening and closing position indicator of the mechanism may occur. For this purpose, another set of opening and closing position indicators is directly installed on the isolating switch body, so that the opening and closing position indicators are mutually confirmed with the opening and closing position indicators of the mechanism.

Disclosure of Invention

In view of the above, the invention aims to provide a double-break isolating switch with position indication, which has reasonable structure and stable insulating performance and can realize extension of a reserved interval under the condition of no power failure.

In order to achieve the above purpose, the technical scheme of the invention is realized as follows:

the double-break isolating switch with the position indication comprises a switch body and an operating mechanism, wherein a switch position indication device is arranged on one side of the switch body, an operating mechanism is arranged on the other side of the switch body, and an operating position indication device is arranged at the bottom of the operating mechanism;

the switch body comprises a shell, an X-phase switch, a Y-phase switch, a Z-phase switch and a plurality of insulating transmission shafts, wherein the X-phase switch, the Y-phase switch and the Z-phase switch are coaxially connected through the insulating transmission shafts, the X-phase switch, the Y-phase switch and the Z-phase switch are sequentially arranged in the shell, a switch position indicating device is arranged on one side of the shell, and the other side of the shell is connected with the operating mechanism through a shaft sealing part.

Further, the X-phase switch comprises a moving contact assembly, a first static contact seat of an isolating switch, a second static contact seat of the isolating switch and a supporting component, wherein the bottom of the moving contact assembly is installed in the shell through the supporting component, the first static contact seat of the isolating switch is installed on the right side of the moving contact assembly, the second static contact seat of the isolating switch is installed on the left side of the moving contact assembly, and the moving contact assemblies are respectively connected with an insulating transmission shaft;

the X-phase switch, the Y-phase switch and the Z-phase switch have the same structure.

Further, the supporting component comprises a pillar insulator and a cover plate, and the pillar insulator is connected with the cover plate through bolts; the movable contact assembly is mounted to a pillar-type insulator by a screw, and the pillar-type insulator is used for fixedly supporting the movable contact assembly and separating the movable contact assembly at a charged position from a low-potential shell in an insulating manner; the cover plate is connected with the shell through bolts.

Further, the X-phase switch further comprises a plurality of basin-type insulators, each basin-type insulator comprises a resin portion for insulation and an insert portion for conduction, the first static contact seat of the isolating switch and the second static contact seat of the isolating switch are fixed on the insert portions of the basin-type insulators through screws respectively, the basin-type insulators are mounted to flanges at two ends of the shell through screws and used for fixedly supporting the first static contact seat of the isolating switch and the second static contact seat of the isolating switch, and the first static contact seat of the isolating switch and the second static contact seat of the isolating switch at the electrified position are isolated from the shell through insulation.

Further, the movable contact assembly comprises a gear, two groups of racks and two groups of movable contact rods, wherein the gear is respectively meshed with the two groups of racks, and each group of racks is respectively fixedly connected with one group of movable contact rods.

Further, the working state of the double-break isolating switch comprises a closing state and a separating state, when the double-break isolating switch is in the closing state, two groups of moving contact rods of the moving contact assembly are respectively inserted into a first static contact seat of the first isolating switch and a second static contact seat of the second isolating switch, and the conducting between the moving contact assembly and the static contact seat is realized through watchband contact fingers arranged in the first static contact seat of the first isolating switch and the second static contact seat of the second isolating switch, and current forms a loop from a left end basin-type insulator insert part to a right end left end basin-type insulator insert part.

Further, in the opening state, the two groups of moving contact rods of the moving contact assembly are separated from or disconnected with the first static contact seat of the first isolating switch and the second static contact seat of the second isolating switch respectively; the movable contact assembly and the first static contact seat of the isolating switch form an isolating fracture I, and the movable contact assembly and the second static contact seat of the isolating switch form an isolating fracture II; the isolation fracture I and the isolation fracture II are relatively independent.

Further, the implementation modes of the isolation fracture I and the isolation fracture II are as follows: when the operating mechanism acts, the output shaft of the operating mechanism is driven to rotate, and the output shaft of the operating mechanism outputs torque, so that the shaft sealing part of the switch body connected with the operating mechanism and the insulating transmission shaft are driven to rotate;

then, the insulating transmission shaft drives a gear inside the moving contact assembly to rotate.

Furthermore, the transmission of torque is realized through spline fit of the same specification between the output shaft of the operating mechanism and the shaft sealing part, between the shaft sealing part and the insulating transmission shaft and between the insulating transmission shaft and the gear.

Furthermore, the shell is a three-phase casting shell, a sealed pressure air chamber is arranged in the shell, and SF6 gas with rated pressure is filled when the product runs.

Compared with the prior art, the double-break isolating switch with the position indication has the following advantages:

the invention discloses a double-break isolating switch with position indication, which aims to meet the requirement that GIS reserved intervals provided by national network companies are not powered off in the whole process of two-stage extension installation and field handover test. Meanwhile, the device has the advantages of reasonable design structure, stable performance, low manufacturing cost, convenience in installation and safety and reliability in operation.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention. In the drawings:

FIG. 1 is a schematic view of an overall structure according to an embodiment of the present invention;

FIG. 2 is a schematic view of the inside of the overall structure according to the embodiment of the present invention;

FIG. 3 is a schematic view of the inside of the overall structure (open state) according to the embodiment of the present invention;

fig. 4 is a schematic view of the inside (closing state) of the overall structure according to the embodiment of the present invention;

FIG. 5 is a schematic diagram of a switch position indicator according to an embodiment of the present invention;

FIG. 6 is a schematic view of an operation position indicating device according to an embodiment of the present invention;

fig. 7 is a schematic diagram of an engineering application according to an embodiment of the present invention.

Reference numerals illustrate:

1. a switch body; 1.1, a switch position indicating device; 2. an operating mechanism; 2.1, operating a position indicating device; 3. a shaft seal portion; 4. a moving contact assembly; 5. the first static contact seat of the isolating switch; 6. the second static contact seat of the isolating switch; 7. a support member; 7.1, a pillar insulator; 7.2, cover plate; 8. an insulated transmission shaft; 9. a housing; 10. a gear; 11. a rack; 12. a movable contact rod; 13. needle roller bearings; 14. watchband contact fingers; 15. basin-type insulator; 15.1, resin part; 15.2, insert portion.

Detailed Description

It should be noted that, without conflict, the embodiments of the present invention and features of the embodiments may be combined with each other.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first", "a second", etc. may explicitly or implicitly include one or more such feature. In the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art in a specific case.

The invention will be described in detail below with reference to the drawings in connection with embodiments.

As shown in fig. 1 to 6, a double-break isolating switch with position indication is provided, and a single operating mechanism is adopted to realize that two breaks of each phase can be simultaneously subjected to opening and closing operations. The isolating switch comprises a switch body 1 and an operating mechanism 2. In the present invention, the internal components of the operating mechanism 2 are not improved, and the operating mechanism 2 is in the prior art, so long as the insulating transmission shaft 8 can be driven to rotate.

The switch body 1 of the isolating switch has three phases (X phase, Y phase and Z phase respectively) and is of a three-phase common box structure, namely, three-phase switches are all arranged in the same shell. The inside of the shell is a sealed pressure air chamber, and SF6 gas with rated pressure is filled when the product runs. The switch body 1 is connected with the operating mechanism 2 through a shaft sealing part 3 on the shell. The transmission mode of the isolating switch adopts three-phase mechanical linkage, namely, the three-phase switches are connected through an insulating transmission shaft 8, so that the transmission synchronism among the three-phase switches is ensured.

The double-fracture isolating switch adopts a single operating mechanism to realize mechanical linkage of two fractures of each phase, namely, the operating mechanism 2 is fixed on the shell 9 of the switch body 1 through a mechanism shell and is connected with the shaft sealing part 3 on the shell through the output shaft of the operating mechanism 2. When the operating mechanism 2 is operated, the output shaft of the operating mechanism 2 rotates, so that the insulating transmission shaft 8 is driven to rotate, and the separation and combination operation of the isolating switch is realized.

Each phase switch of the isolating switch in the scheme comprises an isolating switch moving contact assembly 4, an isolating switch first static contact seat 5 and an isolating switch second static contact seat 6. In the opening state, the isolating switch moving contact assembly 4 and the isolating switch first static contact seat 5 form an isolating fracture I; the movable contact assembly 4 and the second static contact seat 6 of the isolating switch form an isolating fracture II. Each group of fracture is relatively independent and is not affected by each other. The opening and closing operation of each group of fracture is synchronously carried out, and the operation mechanism 2 drives the fracture to realize the same mode.

Such structures have passed all test projects related to insulation, temperature rise, dynamic thermal stability of the western-style high-voltage electrical equipment institute. And acquiring a certificate passing through the related test item qualification. At present, a plurality of projects are put into operation in related projects of a national power grid, such as Ji Xindian, ganyuan and the like.

Example 1

As shown in FIG. 1, the double-break isolating switch structure with position indication is designed, and a single operating mechanism is adopted to realize that two breaks of each phase can simultaneously carry out opening and closing operations. The isolating switch comprises a switch body 1 and an operating mechanism 2. An operating position indicating device 2.1 (see fig. 2) is provided in the operating mechanism 2, and a switch position indicating device 1.1 is also provided in the switch body 1 for observing and confirming the opening and closing positions of the disconnecting switch.

As shown in fig. 2, the switch body 1 of the isolating switch has three phases (X phase, Y phase and Z phase respectively) and has a three-phase common box structure, that is, three-phase switches are all disposed in the same housing 9. Inside the outer casing 9 is a sealed pressure air chamber, and SF6 gas with rated pressure is filled in the product during operation. The switch body 1 is connected with the operating mechanism 2 through a shaft sealing part 3 on the shell 9. Each phase of switch comprises a moving contact assembly 4, a first static contact seat 5 of a disconnecting switch, a second static contact seat 6 of the disconnecting switch and a supporting part 7 of the moving contact assembly 4. The transmission mode of the isolating switch adopts three-phase mechanical linkage, namely, the three-phase switches are connected through an insulating transmission shaft 8, so that the transmission synchronism among the three-phase switches is ensured. The double-fracture isolating switch adopts a single operating mechanism to realize mechanical linkage of two fractures of each phase, namely, the operating mechanism 2 is fixed on the shell 9 of the switch body 1 through a mechanism shell and is connected with the shaft sealing part 3 on the shell through an output shaft of the mechanism 2. The shaft sealing part 3 can rotate, and meanwhile, the air tightness between the shaft sealing part and the shell 9 is kept, so that the stability of SF6 gas pressure in the shell is ensured.

As shown in fig. 3 and 4, each phase switch of the isolating switch comprises an isolating switch moving contact assembly 4, an isolating switch first static contact seat 5, an isolating switch second static contact seat 6, and a supporting component 7 of the moving contact assembly 4.

The support member 7 includes a post insulator 7.1 and a cover plate 7.2, and the post insulator 7.1 and the cover plate 7.2 are fixedly connected by bolts. The moving contact assembly 4 is fixed on the pillar insulator 7.1 by using screws, and the pillar insulator 7.1 can fixedly support the moving contact assembly 4 and electrically isolate the moving contact assembly 4 at a charged position from the low-potential shell 9. The cover plate 7.2 is fixedly connected with the housing 9 by bolts.

The first static contact seat 5 and the second static contact seat 6 are fixed at the insert parts of the basin-type insulators 15 by bolts respectively, and each basin-type insulator 15 comprises a resin part 15.1 for insulation and an insert part 15.2 for conduction. The basin-type insulator 15 is fixed on flanges at two ends of the shell 9 by using screws, and is used for fixedly supporting the first static contact seat 5 of the isolating switch and the second static contact seat 6 of the isolating switch, and insulating the static contact seat of the electrified part from the shell 9.

As shown in fig. 4, when the isolating switch is in a closing state, two groups of moving contact rods 12 of the moving contact assembly 4 are respectively inserted into a first static contact seat 5 of the isolating switch and a second static contact seat 6 of the isolating switch, and the conducting between the moving contact assembly 4 and the static contact seat is realized through watchband contact fingers 14 installed in the static contact seats, and the current forms a loop from a left end basin-type insulator insert to a right end basin-type insulator insert.

As shown in fig. 3, in the opening state, the two groups of movable contact rods 12 of the movable contact assembly 4 are separated from and disconnected from the first fixed contact seat 5 of the first isolating switch and the second fixed contact seat 6 of the second isolating switch respectively; the moving contact assembly 4 and the first static contact seat 5 of the isolating switch form an isolating fracture I, and the moving contact assembly 4 and the second static contact seat 6 of the isolating switch form an isolating fracture II. Each group of fracture is relatively independent and is not affected by each other. The opening and closing operation of each group of fracture is synchronously carried out, and the operation mechanism 2 drives the fracture to realize the same mode.

The implementation mode of the isolation fracture is as follows: when the operating mechanism 2 acts, the output shaft of the operating mechanism 2 is driven to rotate first to output torque, so that the shaft sealing part 3 and the insulating transmission shaft 8 of the switch body 1 connected with the operating mechanism are driven to rotate. Then, the insulating transmission shaft 8 drives the gear 10 inside the moving contact assembly 4 to rotate. The transmission of torque is realized by spline fit of the same specification between the output shaft of the mechanism and the shaft sealing part 3, between the shaft sealing part 3 and the insulating transmission shaft 8 and between the insulating transmission shaft 8 and the gear 10.

The gear 10 is meshed with the rack 11, the rack 11 is fixedly connected with the movable contact rod 12, and through the cooperation of the gear and the rack, the rotation of the gear 10 is converted into the direct motion of the rack 11, so that the direct motion sliding of the movable contact rod 12 is realized, and the separation and the combination of each phase of isolating switch are realized. The movable contact assembly 4 comprises two groups of racks 11 and movable contact rods 12, the two groups of racks 11 and the movable contact rods 12 are meshed with the gear 10 at the same time, and the power of the gear 10 is synchronously received, so that the synchronism of the two groups of racks 11 and the movable contact rods 12 can be ensured, and the synchronism between the same-phase isolation fracture I and the same-phase isolation fracture II is realized.

In a preferred embodiment of the invention, the switch bodies 1 of the isolating switch are all arranged in the isolating shell 9, the shell 9 is a three-phase casting shell, namely, the three-phase switch and the inter-phase transmission component are all arranged in the same shell, so that the leakage of the transmission component is reduced, the influence of the environment is reduced, and the stability of the product is improved. The switch shell adopts a casting structure, the size of the space between the three phases is directly ensured by a casting and machining process, the process increases the accuracy of the shell size, reduces the error of product assembly and reduces the workload of product debugging. The three-phase casting shell directly ensures the centering of the product phase space, and provides a good size foundation for the butt joint with other modules. The structure is subjected to simulation calculation in the aspects of electric field, strength and water pressure, and the national relevant standards and regulations can be met.

In a preferred embodiment of the present invention, the isolation break is determined to be formed when the opening/closing position indicator of the isolation switch mechanism indicates the opening position. However, since the opening and closing position indicator of the mechanism is not directly connected to the isolating switch body, an incorrect indication of the opening and closing position indicator of the mechanism may occur. In this scheme, install another set of divide-shut brake switch position indication device 1.1 on the isolator body. The position indicator 1.1 is directly fixed on the insulating transmission shaft 8 of the switch body 1 by a screw nut, and when the mechanism is operated, the insulating transmission shaft 8 rotates to drive the separation and the combination of the isolation fracture I and the isolation fracture II and also drive the position indicator 1.1 to rotate. When the isolating fracture I and the isolating fracture II are stopped in the opening state, the position indicator 1.1 indicates 'opening'; when the isolating switch is stopped in the closed state, the position indicator 1.1 indicates "on". See fig. 5 and 6.

In a preferred embodiment of the invention, the position indicator 1.1 can more accurately reflect the opening/closing position of the disconnector for mutual identification with the operating position indicating device 2.1 than the operating position indicating device 2.1 in the operating mechanism 2.

In a preferred embodiment of the invention, in the disconnector moving contact assembly 4, the two sets of sliding moving contact bars 12 are coaxially arranged, which is relatively simple compared to other eccentrically arranged constructions. The moving contact assembly 4 and the shell 9 adopt a coaxial cylindrical electric field structural design with a more uniform electric field, so that the distance between the moving contact assembly 4 and the inner wall of the shell 9 can be reduced, the size of a cavity of the shell 9 is reduced, and the volume of a product is further reduced.

In a preferred embodiment of the invention, the 4.1 conductor in the disconnector moving contact assembly 4 is cast. And a shielding cover on the movable contact side of the break in conventional design is omitted. The shielding appearance of fracture is directly cast and formed, so that the heat dissipation area of the 4.1 conductor can be increased, and the through-flow capacity of the product is greatly improved.

In a preferred embodiment of the present invention, the 4.1 conductor, the movable contact rod 12, and the first static contact seat 5 and the second static contact seat 6 of the isolating switch are electrically connected by the watchband contact finger 14 in the closing state. Compared with the electrical connection structure of other quincuncial contacts or self-operated contacts, the electrical connection structure of the watchband contact finger 14 greatly increases the number of contacts of the electrical contact, can reduce the resistance and improve the current passing capability of the product. And the number of the electric contact points is increased, so that the abrasion condition of sliding friction of the movable contact rod 12 in the opening and closing process can be improved, and the generation of foreign matter fragments can be reduced.

In a preferred embodiment of the present invention, since the 4.1 conductor is integrally cast, the grooves of the watchband contact fingers 14 are mounted at the left and right ends of the 4.1 conductor, so that the grooves at the two ends can be completely machined by one clamping, which is beneficial to ensuring the coaxiality of the grooves, thereby ensuring the coaxiality of the contact rod 12 during sliding, reducing the abrasion condition of sliding friction and reducing the generation of foreign matter fragments.

In a preferred embodiment of the present invention, in the moving contact assembly 4, when the contact rod 12 moves in the closing direction, the contact rod 12 tends to sag and tilt due to the influence of its own gravity, so that the rack 11 tilts, and the meshing accuracy of the rack and pinion is affected. To avoid this, a bolt type needle bearing 13 is provided at the rack 11, and only relative rolling is provided between the needle bearing 13 and the rack 11, so that tilting of the rack 11 and the contact rod 12 is avoided, thereby ensuring linear movement of the contact rod 12 and the rack 11.

In a preferred embodiment of the present invention, the support member 7 is a pillar insulator, which is compact and lightweight, and has a mature manufacturing process and stable and reliable performance. In order to improve the electric field margin of the insulator, curved surface folds are added on the surface of the insulator so as to increase the creepage distance of the insulator and improve the product margin.

In a preferred embodiment of the invention, a hand hole is arranged below each fracture of the isolating switch, an adsorbent cover is arranged on the hand hole cover plate, and the adsorbent cover adopts a spherical structure and can be used for installing adsorbent; meanwhile, the hand hole can be used as a trap, and foreign matters such as fragments and the like are generated in the opening and closing process of the moving contact, and can directly fall on the spherical adsorbent cover and further fall to a gap between the hand hole cover plate and the hand hole, so that the foreign matters such as fragments and the like are prevented from falling in other high-field-intensity areas to cause discharge accidents.

Engineering application

The isolating switch of the scheme has obtained the qualification certificate of the relevant test items through all types of test items of insulation, temperature rise and dynamic thermal stability relevant to the western electric appliance research institute. At present, a plurality of projects are put into operation in related projects of a national power grid, such as Ji Xindian, ganyuan and the like. Fig. 7 is an example of an engineering application.

As shown in FIG. 7, the isolating switch is in a use position, a first-stage reserved interval structure is arranged in a broken line frame, and a second-stage extension newly-added device is arranged outside the frame.

When the secondary equipment is required to be expanded, the lower mother and the upper mother are electrified (or the single mother is electrified or can be regulated according to the actual working condition of the transformer substation); separating the isolating switch a from the gate, and separating the isolating switch b from the gate; and switching on the ground c, the ground d and the ground e. At this time, two series-arranged isolation breaks (a break a1 and a break a2 formed by the isolation switch a are connected in series, a break b1 and a break b2 formed by the isolation switch b are connected in series) are formed between the butt joint working face and the two buses running in an electrified mode, the position between the break a1 and the break a2 is grounded through the grounding c-type disconnecting link, the position between the break b1 and the break b2 is grounded through the grounding d-type disconnecting link, and the butt joint working face is grounded through the grounding e-type disconnecting link. At the moment, the second-stage equipment can be docked, and the transformer substation runs in an electrified mode. Two series-arranged isolation fractures (the fracture a1 and the fracture a2 are connected in series and the fracture b1 and the fracture b2 are connected in series) are arranged between the butt joint working face and the two buses in electrified operation. In the process of butt joint of the secondary equipment, once the break-over of any bus and the butt joint part of power failure occurs, only the break-over a1 (or the break-over b 1) close to the electrified side is broken down, and the break-over a2 (and the break-over b 2) close to the power failure side are not broken down. Further, since the ground c (and the ground d) is already grounded, even if the break a1 (or the break b 1) is broken down, the generated breakdown current is directly discharged through the ground c (or the ground d) to the ground, without affecting the break a2 (and the break b 2). Thereby guaranteeing the safety of constructors to the greatest extent.

After the secondary equipment is in butt joint, the power frequency voltage withstand test is required to be carried out on newly installed equipment independently, and at the moment, both the lower mother and the upper mother are electrified (or single mother is electrified or can be regulated according to the actual working condition of the transformer substation); the isolating switch a is separated from the gate, and the isolating switch b is separated from the gate; the method comprises the steps of carrying out a first treatment on the surface of the And switching on the ground c, switching on the ground d and switching off the ground e. When the power frequency voltage withstand test is carried out on newly installed equipment, the lower bus and the upper bus can be in an electrified running state (or single bus electrified can be regulated according to the actual working condition of a transformer substation), and two serially arranged fractures (the fracture a1 and the fracture a2 are serially connected, and the fracture b1 and the fracture b2 are serially connected) are respectively arranged between the electrified bus and the test unit. In the voltage withstand test process, once the break breakdown of the test unit and the live operation part occurs, only the break a2 (or the break b 2) close to the test unit breaks down, but the isolation break a1 (and the isolation break b 1) close to the live operation bus side does not break down. Moreover, since the ground c (and the ground d) is already grounded, even if the isolation break a2 (or the isolation break b 2) is broken down, the generated breakdown current is directly released through the ground c (or the ground d) without affecting the isolation break a1 (and the isolation break b 1). Thereby guaranteeing the safety of constructors to the greatest extent.

After the field test is completed, the isolating switches and the grounding switches can be adjusted to corresponding states according to the actual working conditions of the transformer substation.

According to the analysis, the GIS reservation interval of the double-fracture disconnecting switch with the scheme has no power failure in the whole process of expanding the secondary equipment (the installation butt joint process and the handover test process), and the normal operation of the transformer substation is ensured. And the pressure test range comprises all newly installed secondary equipment, so that the full coverage and no dead zone of the pressure test range are realized.

The double-break isolating switch structure design with the position indication aims at meeting the requirement that GIS reservation intervals proposed by national network company are not powered off in the whole process of second-stage extension installation and field handover test. Meanwhile, the device has the advantages of reasonable design structure, stable performance, low manufacturing cost, convenience in installation and safety and reliability in operation.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the invention.

Claims (10)

1. A double-break isolating switch with position indication is characterized in that: the switch comprises a switch body (1) and an operating mechanism (2), wherein a switch position indicating device (1.1) is arranged on one side of the switch body (1), the operating mechanism (2) is arranged on the other side of the switch body (1), and the operating position indicating device (2.1) is arranged at the bottom of the operating mechanism (2);

the switch body (1) comprises a shell (9), an X-phase switch, a Y-phase switch, a Z-phase switch and a plurality of insulating transmission shafts (8), wherein the X-phase switch, the Y-phase switch and the Z-phase switch are coaxially connected through the insulating transmission shafts (8), the X-phase switch, the Y-phase switch and the Z-phase switch are sequentially arranged in the shell (9), a switch position indicating device (1.1) is arranged on one side of the shell (9), and the other side of the shell (9) is connected with an operating mechanism (2) through a shaft sealing part (3).

2. A dual-break disconnector with position indication as claimed in claim 1, characterized in that: the X-phase switch comprises a moving contact assembly (4), a first isolating switch static contact seat (5), a second isolating switch static contact seat (6) and a supporting component (7), wherein the bottom of the moving contact assembly (4) is installed into a shell (9) through the supporting component (7), the first isolating switch static contact seat (5) is installed on the right side of the moving contact assembly (4), the second isolating switch static contact seat (6) is installed on the left side of the moving contact assembly (4), and the moving contact assembly (4) is respectively connected with an insulating transmission shaft (8);

the X-phase switch, the Y-phase switch and the Z-phase switch have the same structure.

3. A dual-break disconnector with position indication as claimed in claim 2, characterized in that: the supporting component (7) comprises a pillar insulator (7.1) and a cover plate (7.2), and the pillar insulator (7.1) is connected with the cover plate (7.2) through bolts; the movable contact assembly (4) is mounted to a pillar-type insulator (7.1) through a screw, and the pillar-type insulator (7.1) is used for fixedly supporting the movable contact assembly (4) and insulating and distinguishing the movable contact assembly (4) at a charged position from a low-potential shell (9); the cover plate (7.2) is connected with the shell (9) by bolts.

4. A dual-break disconnector with position indication as claimed in claim 2, characterized in that: the X-phase switch further comprises a plurality of basin-type insulators (15), each basin-type insulator (15) comprises a resin part (15.1) for insulation and an insert part (15.2) for conduction, the first static contact seat (5) of the isolating switch and the second static contact seat (6) of the isolating switch are fixed on the insert parts (15.2) of the basin-type insulators (15) by screws respectively, the basin-type insulators (15) are mounted to flanges at two ends of the shell (9) by screws and are used for fixedly supporting the first static contact seat (5) of the isolating switch and the second static contact seat (6) of the isolating switch and insulating the first static contact seat (5) of the isolating switch and the second static contact seat (6) of the isolating switch at the electrified position from the shell (9).

5. A dual-break disconnector with position indication as claimed in claim 2, characterized in that: the movable contact assembly (4) comprises a gear (10), two groups of racks (11) and two groups of movable contact rods (12), wherein the gear (10) is meshed with the two groups of racks (11) respectively, and each group of racks (11) is fixedly connected with one group of movable contact rods (12) respectively.

6. A dual-break disconnector with position indication as claimed in claim 5, characterized in that: the working state of the double-fracture disconnecting switch comprises a closing state and a separating brake state, when the double-fracture disconnecting switch is in the closing state, two groups of movable contact rods (12) of the movable contact assembly (4) are respectively inserted into a first static contact seat (5) of the disconnecting switch and a second static contact seat (6) of the disconnecting switch, and the movable contact assembly (4) and the static contact seat are conducted through watchband contact fingers (14) arranged in the first static contact seat (5) of the disconnecting switch and the second static contact seat (6) of the disconnecting switch, and current forms a loop from an insert part (15.2) of a left-end basin-type insulator (15) to an insert part (15.2) of a right-end left-end basin-type insulator (15).

7. A dual-break disconnector with position indication as claimed in claim 6, characterized in that: in the opening state, two groups of movable contact rods (12) of the movable contact assembly (4) are separated from or disconnected with the first static contact seat (5) of the first isolating switch and the second static contact seat (6) of the second isolating switch respectively; the movable contact assembly (4) and the first static contact seat (5) of the isolating switch form an isolating fracture I, and the movable contact assembly (4) and the second static contact seat (6) of the isolating switch form an isolating fracture II; the isolation fracture I and the isolation fracture II are relatively independent.

8. A dual-break disconnector with position indication as claimed in claim 7, characterized in that: isolation fracture I and isolation fracture II implementation mode: when the operating mechanism (2) acts, the output shaft of the operating mechanism (2) is driven to rotate, and the output shaft of the operating mechanism (2) outputs torque, so that the shaft sealing part (3) of the switch body (1) connected with the operating mechanism and the insulating transmission shaft (8) are driven to rotate;

then, the insulating transmission shaft (8) drives the gear (10) inside the movable contact assembly (4) to rotate.

9. A dual-break disconnector with position indication as claimed in claim 5, characterized in that: the torque transmission is realized through spline matching with the same specification between the output shaft of the operating mechanism (2) and the shaft sealing part (3), between the shaft sealing part (3) and the insulating transmission shaft (8) and between the insulating transmission shaft (8) and the gear (10).

10. A dual-break disconnector with position indication as claimed in claim 1, characterized in that: the shell (9) is a three-phase casting shell, a sealed pressure air chamber is arranged in the shell (9), and SF6 gas with rated air pressure is filled when the product runs.