CN211719500U - Sleeve for reducing partial discharge of ZW20 switch complete machine - Google Patents

Abstract

The utility model provides a reduce ZW20 switch complete machine partial discharge's sleeve pipe, the sleeve pipe passes box and current transformer, the sleeve pipe includes the sleeve pipe overcoat, be provided with the insulating part in the sleeve pipe overcoat, the inside sealing washer that is provided with of insulating part, the insulating part cover is established on the wire, be provided with the shielding net in the insulating part, the shielding net sets up the sleeve pipe passes box and current transformer's position, the shielding net is cylindrical, diameter 60mm, length 130mm, the shielding net passes through wire and earth electric connection, selects through special size and forms a parallel electric field between high voltage and the earth, and outside extending the box with the electric field that the switch box is close to simultaneously, keeping away from the ground potential, shields current transformer simultaneously, avoids inside coil to have the problem that the electric field concentrates.

Description

Sleeve for reducing partial discharge of ZW20 switch complete machine

Technical Field

The utility model relates to an electrical equipment technical field, in particular to reduce ZW20 switch complete machine partial discharge's sleeve pipe.

Background

At present, local discharge of a pole-mounted switch plays a role in promoting deterioration of insulation, and insulation damage of the switch is caused to cause line faults. Aiming at the partial discharge problem of a column vacuum circuit breaker ZW20 switch, a key point causing partial discharge is found, the overall partial discharge of the switch is reduced and controlled in the switch production process, and the possibility of line faults caused in the operation process of the switch partial amplification is reduced from the source.

The partial discharge is a discharge that occurs between the electrodes but does not penetrate the electrodes, and is a phenomenon in which repeated breakdown and extinction occur under the effect of high electric field strength due to a weak point inside the insulation of the device or a defect caused during the production process. It is expressed as the breakdown of gas in the insulation, the local breakdown of solid or liquid medium in a small range, or the local breakdown discharge caused by the concentration of the field intensity at the edge and sharp corner of the metal surface.

In the switch insulation system, the electric field intensity of each part has difference, when the electric field intensity of a region reaches the breakdown field intensity, the region has discharge phenomenon, however, the whole discharge process is not penetrated between two conductors applying voltage, namely, the discharge does not break down the insulation system, and the phenomenon is partial discharge. The electric field distribution in the insulating medium, the electrical and physical properties of the insulation, and the like determine the conditions under which partial discharge occurs, and in general, partial discharge easily occurs under conditions of high electric field strength and low electrical strength. Although partial discharges do not generally penetrate through the insulation, they can locally damage the dielectric, which, if present over a long period of time, can reduce the electrical strength of the insulating medium under certain conditions. Therefore, partial discharge belongs to hidden danger in electrical equipment, and the damage process of the partial discharge shows the characteristics of slowness and long-term property. Usually, the characteristic of partial discharge can better verify the insulation defect, and the partial damage degree of the insulation can be analyzed through the characteristic of partial discharge. Various partial discharge characteristics are comprehensively measured to a great extent, and the insulation level of the product can be objectively evaluated.

Hazards of partial discharge:

harming one: the electrical effect, the discharge capacity, is so small that its short-term presence does not affect the dielectric strength of the electrical apparatus. However, if partial discharges occur continuously in the electrical equipment under the operating voltage, the weak discharges will generate cumulative effects to gradually deteriorate the dielectric properties of the insulation and enlarge local defects, and finally, the whole insulation breakdown is caused. If partial discharge exists for a long time, the partial discharge test of the power equipment can lead to insulation degradation and even breakdown, so that the insulation condition of the equipment can be known, and the reason and the severity of insulation fault can be determined by finding out a plurality of problems related to manufacturing and installation in time.

And (2) harming: the heat effect may cause thermal or chemical decomposition of the medium because the medium temperature can rise to 170 ℃ within 10-7 seconds due to the occurrence of one partial discharge in a partial volume of 5X 10-17 m near the surface of the medium, and sometimes even to a high temperature of 1000 ℃ due to the discharge effect. In addition to the heat-removing effect, the light effect (mainly in the ultraviolet range) generated by partial discharge can also cause the phenomena of light aging, cracking and the like of the plastic organic medium.

And (3) harming: chemical action, the erosion of the medium may be greater than the result of electrical or thermal action due to excited molecules produced by partial discharge or due to secondary products.

Species characteristic of partial discharge

Corona discharge: corona discharge often occurs around a gas-enclosed high-voltage conductor, such as a high-voltage transmission line or a high-voltage transformer, and the high-voltage terminals of these high-voltage electrical devices are exposed to air, so that the probability of occurrence of corona discharge is relatively high. Corona discharge is characterized by a typical, extremely non-uniform electric field, and is also a characteristic self-sustaining discharge form under the extremely non-uniform electric field. Many external factors affect the corona onset voltage, such as electrode shape, applied voltage, gas density, interpolar distance, and void humidity and flow velocity.

Creeping discharge: creeping discharge usually occurs on the surface of the insulating medium. The partial discharge mode belongs to a special gas discharge phenomenon, and the end parts of power cables, motor windings, insulating sleeves and the like are commonly subjected to creeping discharge. Once the electric field inside the dielectric is lower than the electric field at the air gap at the edge of the electrode, and the dielectric breakdown voltage is relatively low, creeping discharge occurs at the surface of the insulating dielectric. Generally, the voltage waveform, the distribution of the electric field, the air quality, the surface state of the medium, the weather condition and the like all influence the creeping discharge voltage, so the creeping discharge presents the characteristic of instability.

Internal discharge: internal discharges are relatively common inside solid insulating media. The problem of material and process defects is inevitable when the insulating medium is produced and processed, so that internal defects such as doping of a small amount of air or impurities and the like occur inside the insulating medium. Once the insulation is exposed to high voltages, internal defects may cause localized or repetitive breakdown. Generally, the characteristics of the medium itself, the size of the air gap, the position and shape of the defect, the kind of air gap gas, and the like affect the conditions for generating the internal discharge.

Suspension potential discharge: the form of partial discharge means that a conductor part in a high-voltage device has structural design defects or is in poor contact due to other reasons, and finally the part is positioned between a high-voltage electrode and a low-voltage electrode and obtains partial pressure according to the impedance ratio of the positions of the conductor part to generate discharge, and the conductor part is called as a floating potential with respect to the ground potential. When a conductor has a floating potential, the field strength in its vicinity is usually relatively concentrated and can disrupt the formation of the surrounding insulating medium. In general, in an electrical apparatus, floating potential discharge easily occurs in a high-potential metal part or a metal part at a ground potential.

By analyzing the mechanism and reason generated by partial discharge, testing the partial discharge capacity of the ZW20 complete machine and each key component, and simulating the whole structure of the switch by ANSYS software, the fact that the complete machine of the switch has a great relation with the electric field intensity inside the switch besides the relation with each component of the switch, especially in an electric field concentrated region, an electric field with obvious high concentration exists between a switch incoming and outgoing line sleeve and a current transformer, the analysis current transformer is a low-voltage element which is sleeved on the switch sleeve and has a place with concentrated electric field intensity, and meanwhile, the sleeve penetrates through a switch box body and also has concentrated electric field intensity, so the electric field intensity between the switch sleeve and the low-voltage current transformer and the switch box body needs to be reduced, the electric field is distributed uniformly, and the partial discharge can.

SUMMERY OF THE UTILITY MODEL

For overcoming the defects of the prior art, the utility model provides a technical scheme does: the utility model provides a reduce ZW20 switch complete machine partial discharge's sleeve pipe, the sleeve pipe passes box and current transformer, the sleeve pipe includes the sleeve pipe overcoat, be provided with the insulating part in the sleeve pipe overcoat, the inside sealing washer that is provided with of insulating part, the insulating part cover is established on the wire, be provided with the shielding net in the insulating part, the shielding net sets up the sleeve pipe passes box and current transformer's position, the shielding net is cylindrical, diameter 60mm, length 130mm, the shielding net passes through wire and earth electric connection.

Preferably, the sleeve housing is made of silicone rubber.

Preferably, the shielding net is made of a 100-mesh diagonal shielding net.

Preferably, the insulating member is integrally cast by epoxy resin,

preferably, the number of the sealing rings is two, and the two sealing rings are uniformly distributed in the insulating part and attached to the conducting wire.

Preferably, the current transformer is sleeved outside the sleeve jacket and arranged in the box body.

Preferably, the wire terminal passes in from one end of the bushing where the current transformer is located and out from the other end.

Preferably, a secondary outlet is arranged in the middle of the insulating part, and the conducting wire of the shielding net and the ground is penetrated out from the secondary outlet.

Preferably, the sleeve comprises an AC phase sleeve and a B phase sleeve, the part of the AC phase sleeve penetrating out of the box body is provided with a 40-degree bend, and the B phase sleeve is a straight pipe.

The beneficial effects of the utility model are embodied in the following aspect:

the utility model discloses a will with the part that the sleeve pipe passed box and current transformer increase a shielding layer the shielding layer passes through wire and ground electric connection, plays balanced electric field's effect, the shielding layer comprises cylindrical copper mesh, diameter 60mm, length 130mm, selects through special size and forms a parallel electric field between high voltage and the ground, and outside extending to the box with the electric field that the switch box is close to simultaneously, keeping away from the ground potential, shielding current transformer simultaneously, avoiding inside coil to have the problem that the electric field is concentrated.

Drawings

FIG. 1 is a schematic view of the AC phase casing structure of the present invention;

fig. 2 is a schematic diagram of the structure of the phase B casing of the present invention.

FIG. 3 is a field intensity distribution diagram of a conventional bushing;

fig. 4 is the field intensity distribution diagram of the present invention.

In the shown drawing, a box body 1, a current transformer 2, a sleeve jacket 3, an insulating part 4, a sealing ring 5, a shielding net 6, a lead terminal 7, a secondary outlet 8, an AC phase sleeve 9 and a B phase sleeve 10 are arranged.

Detailed Description

The present invention is further described in detail below with reference to the drawings so that those skilled in the art can implement the invention with reference to the description.

As shown in fig. 1-2, a bushing for reducing partial discharge of a whole ZW20 switch comprises an AC phase bushing 9 shown in fig. 1 and a B phase bushing 10 shown in fig. 2, wherein the part of the AC phase bushing 9, which penetrates out of a box body 1, is provided with a 40-degree bend, the B phase bushing 10 is a straight pipe, the bushing penetrates through the box body 1 and a current transformer 2, a lead terminal 7 penetrates through the current transformer 2 from one end of the bushing and penetrates out of the other end, the current transformer 2 is sleeved outside the bushing jacket 3 and is arranged in the box body 1, the bushing comprises a bushing jacket 3, the bushing jacket is made of silicon rubber, an insulating piece 4 is arranged in the bushing jacket 3, a sealing ring 5 is arranged inside the insulating piece 4, the insulating piece 4 is sleeved on a lead, two sealing rings 5 are arranged and uniformly distributed inside the insulating piece 4 and are attached to the lead, the insulation part is formed by pouring epoxy resin integrally, a shielding net 6 is arranged in the insulation part 4, and the shielding net 6 is made of a 100-mesh twill shielding net. The shielding net 6 sets up the position that the sleeve pipe passed box 1 and current transformer 2, shielding net 6 is cylindrical, diameter 60mm, length 130mm, the middle part of insulating part 4 is provided with secondary outlet 8, shielding net 6 is worn out from secondary outlet 8 with the wire of ground UNICOM, shielding net 6 passes through wire and ground electric connection.

Right the utility model discloses with ordinary ANSYS software simulation test for the sleeve pipe, the result is shown in fig. 3-fig. 4, through increasing shielding net 6, ZW20 switch sleeve installs on switch box 1, and current transformer 2 wears on the sleeve pipe, and field intensity is even, tests the switch complete machine simultaneously, singly relatively puts under 14.4kV voltage in office and stabilizes within 10 PC.

While embodiments of the invention have been disclosed above, it is not intended to be limited to the applications listed in the specification and the examples. It can be applicable to various and be fit for the utility model discloses a field completely. Additional modifications will readily occur to those skilled in the art. The invention is therefore not to be limited to the specific details and illustrations shown and described herein, without departing from the general concept defined by the claims and their equivalents.

Claims (9)

1. The utility model provides a reduce ZW20 switch complete machine partial discharge's sleeve pipe, its characterized in that, the sleeve pipe passes box and current transformer, the sleeve pipe includes the sleeve pipe overcoat, be provided with the insulating part in the sleeve pipe overcoat, the inside sealing washer that is provided with of insulating part, the insulating part cover is established on the wire, be provided with the shielding net in the insulating part, the shielding net sets up the position that the sleeve pipe passed box and current transformer, the shielding net is cylindrical, diameter 60mm, length 130mm, the shielding net passes through wire and earth electric connection.

2. The bushing for reducing partial discharge of a ZW20 switch complete machine as claimed in claim 1, wherein the bushing outer sleeve is made of silicone rubber.

3. The bushing for reducing partial discharge of a ZW20 switch complete machine as claimed in claim 1, wherein the shielding net is made of 100-mesh diagonal shielding net.

4. The bushing for reducing the partial discharge of the ZW20 switch complete machine as claimed in claim 1, wherein the insulation member is integrally cast by epoxy resin.

5. The bushing for reducing the partial discharge of the ZW20 switch complete machine as claimed in claim 1, wherein the number of the sealing rings is two, and the two sealing rings are uniformly distributed in the insulating part and attached to the conducting wire.

6. The bushing for reducing the partial discharge of the ZW20 switch complete machine as claimed in claim 1, wherein the current transformer is sleeved outside the bushing outer sleeve and arranged in the box body.

7. The bushing for reducing partial discharge of a ZW20 switch complete machine as claimed in claim 1, wherein the lead wire terminal penetrates into the bushing from one end where the current transformer is arranged and penetrates out from the other end.

8. The bushing for reducing partial discharge of a ZW20 switch complete machine as claimed in claim 1, wherein the middle part of the insulating member is provided with a secondary outlet, and the conducting wire of the shielding net and the ground are led out from the secondary outlet.

9. The bushing for reducing partial discharge of the whole ZW20 switch according to claim 1, wherein the bushing comprises an AC phase bushing and a B phase bushing, the AC phase bushing is provided with a 40-degree bend through the box body, and the B phase bushing is a straight tube.

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