KR101956856B1 - Polymer bushing structure of the distribution switch and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a polymer bushing structure of switchgear which comprises: a primary housing structure which is formed by insulator-molding for each individual component which is an embedded mold product; and a secondary housing structure which is entirely formed by insulator-molding for each individual component of switchgear which is primarily housed. To this end, a bushing is improved not to generate a molding defect, damage, a crack and the like while existing busing performance is satisfied so that failure of a switchgear product can be reduced and a power outage accident rate can be reduced, thereby maximizing expectation effects.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer bushing structure and a manufacturing method thereof,

The present invention relates to a switchgear bushing structure and more particularly to a switchgear bushing structure that improves the bushing structure so as not to cause defective molding, breakage or cracking while satisfying the bushing performance of existing switchgear, To the bushing structure of the switchgear flow.

Generally, electricity with a voltage of about 20,000V from the power plant is boosted to ultra high voltage to be transmitted to the first substation to be suitable for transmission. Then, electricity transmitted to the primary substation is reduced to about 22.9 kv and supplied to the secondary substation or each customer. The electric power supplied from the secondary substation is supplied to the reception facilities of each customer through the distribution system composed of the processing distribution line and the underground distribution line, and is supplied to the low pressure customer receiving the electricity through the high pressure consumer, the high pressure consumer, and various outdoor installation transformers. do.

At this time, a load switch is used for the line separation, branching, and transformer protection of the high voltage distribution system. The load switch distributes the power to the devices used in urban and residential complexes. In the event of a surge or an accident occurring in the power system, the faulty section is separated by quick opening and closing for safety after operation of the circuit breaker, It is a device used to shorten the power outage time by supplying power. Depending on the line, the load switchgear has a working switch and a ground switch.

As a working load switch, as shown in Figs. 1a and 1b, a gas insulated switchgear which is sealed with gas or dispersed in air is used. In the case of gas insulated switchgear, SF6 gas is mainly used, but since it is a greenhouse gas reduction target, have.

Nowadays, in the above-described gas insulated switchgear, as shown in Figs. 2A and 2B, an epoxy-insulated insulated bushing structure is applied, which is being converted into a solid insulated switchgear.

For example, the Eco load switch is an epoxy insulation type vacuum load switch installed in a 22.9 kV-y processing power distribution line. It is used for line opening and shutting when the power supply line needs to be restored, shutdown work, and load switching.

In addition, the polymer recloser is a polymer-insulated directional recloser for digital automation for distribution automation used in 22.9 kV-y machining distribution lines. It automatically recloses after shutting down the line in the event of a momentary accident, System separation.

Such a load break switch such as an Eco load breaker or a polymer recloser applies an all-epoxy bushing structure as shown in FIG. 3A, and this bushing is used for electric power electrical insulation and line Which is used as a terminal of a transformer or a circuit breaker, and the outside of the bushing is electrically insulated, and a conductor (electric wire) is passed through the inside of the bushing.

FIG. 3B is a side sectional view showing the internal structure of the load switch of FIG. 3A. The load switch includes a bushing 15 as an external housing and a support, a lead-in electrode 11 as an input terminal, A vacuum breaker (VI) 13 for electrically connecting or disconnecting between the lead-in electrode 11 and the lead-out electrode 12, and a circuit breaker 15 for turning on and off the vacuum breaker 17 / RTI > In addition, a current transformer (CT) 14, a voltage detection lead line 17, and a current detection lead line 18 are further added in the bushing 15.

3 (b), the load switch breaker epoxy bushing 15 includes a VI 13, a CT 14, a lead wire 16, lead wires 17 and 18 for voltage and current detection, And drawing electrodes 11, 12, etc., which have a complicated shape, a molding pressure, defective gas drawing, etc., and bubbles are contained therein, resulting in high molding defects.

According to the Korea Electric Power Corporation (KEPCO), the breakdown pattern of the breakdown in 2016 was 18% for bushing cracking due to moisture penetration, 18% for bushing breakdown due to external force, and about 9% for epoxy molding failure, . These problems are common problems in Eco switches, polymer closures, etc., which are applied to distributing switches.

As described above, in the case of the epoxy bushing 15, high molding defects, expensive bushing cracks, and expensive VI and CT mounted inside the bushing are required to be discarded, resulting in cost increase due to disposal of expensive accessories. Since the cost of these accessories is almost the same as the molding cost, there is a problem that a loss cost is large when a failure occurs.

Therefore, in order to solve the disadvantages of the epoxy bushing, it is necessary to improve the structure of the switchgear bushing.

The contents of the background art described above are technical information that the inventor of the present application holds for the derivation of the present invention or acquired in the derivation process of the present invention and is a known technology disclosed to the general public prior to the filing of the present invention I can not.

KR 10-1051230

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to improve a bushing structure so as not to cause defective molding, breakage or cracking while satisfying bushing performance of existing switchgear, And to provide a bushing structure of an opening / closing type flow which can lower the incidence rate.

In order to realize the above-mentioned object, the opening and closing flow bushing structure according to the present invention is characterized in that a primary housing structure is formed by insulator molding which is injected with polymer rubber or insulating material for each individual component such as a built-in molded product VI, And the secondary housing structure is formed by insulator molding which integrally injects all the individual components of the car-housed switchgear.

Further, it is preferable that each individual component is VI or CT.

In addition, it may include a primary insulation bushing covering the VI or CT, and a secondary insulation bushing for entirely insulating the VI and CT housed in the primary insulation bushing and other individual components.

In addition, the material of the primary insulation bushing is preferably FRP or polymer insulation.

It is preferable that the material of the secondary insulation bushing is EPDM rubber or polymer rubber.

In addition, a tertiary insulation bushing is inserted into the upper portion of the primary insulation bushing.

Also, the body is injection-molded in the secondary housing structure, and then a plurality of bushing needles injected separately are sequentially inserted into the body and assembled.

The above and other objects and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: In addition to the principal task solutions as described above, various task solutions according to the present invention will be further illustrated and described.

In the conventional single-type epoxy bushing, when the epoxy molding failure is carried out, the expensive internal components such as VI and CT are disposed of. In the present invention, however, even after the molding is defective, It is environmentally friendly and economical.

In addition, the existing single-type epoxy bushing can cause insulation breakdown due to cracks between epoxy and VI. However, since the mechanical strength is excellent through the FRP primary insulation bushing, cracks are minimized and insulation is achieved through the third insulation bushing It is advantageous to improve the insulation performance by eliminating the blind spot.

 Accordingly, the bushing is improved so as not to cause defective molding, breakage, crack, etc. while satisfying the existing bushing performance, and it is possible to reduce the failure rate of the switchgear product and reduce the occurrence rate of the blackout accident.

Figures 1a and 1b show a general gas insulated switch,
Figures 2A and 2B show a typical solid state insulated switch,
FIG. 3A is a view showing an epoxy bushing structure in the load break switch of FIGS. 2A and 2B, FIG. 3B is a side sectional view showing the internal structure of the bushing shown in FIG.
FIG. 4 is a side cross-sectional view illustrating a structure of an opening and closing flow bushing according to a preferred embodiment of the present invention,
FIG. 5 is a cross-sectional view of a conventional switchgear bushing structure and a switchgear bushing structure according to a preferred embodiment of the present invention.
FIG. 6 is a view showing an example in which the structure of a load switch breaker bushing according to a preferred embodiment of the present invention is integrally formed;
FIG. 7 is a view showing an assembled type production of a load break switch bushing structure according to a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

4 is a side sectional view showing a structure of a load switch breaker bushing according to a preferred embodiment of the present invention, FIG. 5A is a view showing a structure of a conventional switch breaker bushing, FIG. 5B is a side cross- Fig.

4 and 5, a load switch according to a preferred embodiment of the present invention includes a secondary insulation bushing 130 formed in a T shape as a whole, And is inserted into the other end of the secondary insulation bushing 130 at an angle of 90 degrees with respect to the lead-in electrode 11 and vertically inserted into the lead-out electrode 11 as an input terminal, A vacuum interrupter (VI) 13 installed in the secondary insulation bushing 130 for electrically connecting or disconnecting the lead-in electrode 11 and the lead-out electrode 12, A transformer (CT) 14 for use as a measuring or controlling transformer used to enlarge a measuring range, a cutting rod (not shown) for turning on and off the vacuum circuit breaker 13 by up / down movement during load opening and closing, And lead wires 17 and 18 for voltage and current detection.

Here, the switch-type bushing structure 100 according to the preferred embodiment of the present invention includes a VI 13, a CT 14, a lead wire (not shown), lead wires 17 and 18 And electrodes 11 and 12 for drawing in and out, and is formed of three outer housings 150 because of three phases, and has a T shape as a whole.

As shown in FIG. 5A, an epoxy molding insulation bushing 15 is used as a conventional switchgear bushing structure, and integrally molded parts VI (13), CT (14) and the like are integrally molded by epoxy molding Thereby forming a single housing structure.

As shown in FIGS. 4 and 5B, the switchgear bushing structure 100 of the present invention is formed by inserting polymer rubber or insulator for each individual component such as a built-in molded product VI (13) and CT (14) And a secondary housing structure is formed by insulator molding which integrally injects the individual components of the first housing-accommodated switchgear.

First, a cylindrical primary bushing 110 covering the VI 13 is formed. The cylindrical primary insulating bushing 110 has an input terminal connecting portion 112 connected to the input terminal 11 and an input terminal connecting portion 112 connected to the lead electrode 12 as an output terminal, Output terminal connection portion 111 is formed. The output terminal connection part 111 is formed on the side surface in a cylindrical shape since the drawing electrode 12 is formed at an angle of 90 degrees with the lead-in electrode 11. The input terminal connection part 112 and the output terminal connection part 111 May be formed in the form of a hole having a predetermined diameter to which the lead-in electrode 11 or the lead-out electrode 12 is inserted, and the shape of the primary insulation bushing 110 may be limited to a cylindrical shape A cube shape that can cover the vacuum circuit breaker (VI) as a whole and protect it from an external impact, and the like.

In addition, the material of the primary insulation bushing 110 must be electrically insulated from the outside, and it is necessary to protect the vacuum circuit breaker VI, so that it is preferably similar to the material of the outer housing of the vacuum circuit breaker VI. That is, a FRP (glass fiber reinforced plastic) similar to a ceramic material used as an external housing can be used, and a polymer insulation having a mechanical strength and a similar thermal expansion coefficient like a ceramic material is preferable.

In this case, the primary insulation bushing process of the VI 13 is exemplified, but the same applies to the CT 14 in addition to the vacuum circuit breaker. Alternatively, the CT 14 may be individually subjected to the primary insulation bushing or the vacuum interrupter VI CT 14 can be integrated to form a primary insulation bushing. However, if the outer housing material of the CT can be molded the same as or different from the material of the vacuum circuit breaker (VI), and when the VI and the CT are integrated, the FRP material is used. Insulation of the same or similar material as the CT outer housing material is preferred. Also, since it is connected to the output terminal at the time of CT individual primary insulation bushing, it is possible to connect only the output terminal without forming a separate input terminal connection portion.

Next, a secondary insulation bushing 130 is formed to integrally insulate the VI (13), the CT (14), etc., which are the first and second housings, which are housed in the primary insulation bushing 110.

Here, the secondary insulation bushing 130 is an outer housing that can be electrically insulated from the outside of the switchgear and protects and covers the entire molded product with the switchgear. The material of the secondary insulation bushing 130 is preferably an EPDM rubber which can be decomposed and recycled even if it is defective after molding, and polymeric rubbers such as EPDM rubber which can easily peel off the secondary insulation bushing 130 are preferable .

When the injection material of the secondary insulation bushing 130 is molded of a rubber material, rubber material can be easily released when an injection failure occurs. Thus, expensive internal parts such as VI and CT in the secondary insulation bushing 130 To be recycled.

In this case, the vacuum circuit breaker 13 is frequently moved up and down in order to turn the vacuum circuit breaker 13 on and off to open and close the load circuit when the load is opened and closed. The bushing 110 may collide with or collide with the secondary insulation bushing 130 frequently, which may cause noise or damage due to an impact. Accordingly, when assembling the FRP primary insulation bushing 110 and the vacuum circuit breaker 13, the cylindrical tertiary insulation bushing 120 is inserted into the upper part of the FRP primary insulation bushing 110 to mitigate the impact or generate noise. Can be reduced.

The low-elastic foamed urethane foam or the foamed polyethylene polymer is preferably used as a cushioning material for preventing breakage or noise reduction at the time of collision of the tertiary insulation bushing 120.

The input terminal connection portion 112 or the output terminal connection portion 111 may be connected to the secondary insulation bushing 130 through the primary insulation bushing 110 and the secondary insulation bushing 130, 130 are made of a rubber material and can be easily peeled off. Accordingly, the cylindrical tertiary insulation bushing 120 inserted into the upper portion of the FRP primary insulation bushing 110 can cover the input terminal connection portion 112, thereby enabling complete insulation. Also, the tertiary insulation bushing 120 may be formed in the output terminal connection portion 111 as well.

The shape of the tertiary insulation bushing 120 is a structure that can completely cover the input terminal connection portion 112 or the output terminal connection portion, and is a structure in which two or more diameters having different diameters in a cylindrical shape or a concentric shape are stacked But may be formed in a multi-stage cylindrical shape, and is not limited to a cylindrical shape, and may be modified in various forms such as a cube shape.

The material of the tertiary insulation bushing 120 is preferably a polymer material having excellent insulation property as a buffer material for preventing breakage or noise reduction at the time of impact, and having foamability as polyethylene (PE) and polyurethane polymer insulation.

As described above, in the conventional single-type epoxy bushing 15, the expensive internal components VI, CT and the like are disposed of when the epoxy molding failure is caused. However, in the present invention, the secondary insulating bushing 120 It can easily recycle and recycle expensive internal parts, which is environmentally friendly and economical.

In the conventional single-type epoxy bushing 15, insulation breakdown may occur due to cracks between the epoxy and the VI. However, since the mechanical strength is excellent through the FRP primary insulation bushing 110, It is advantageous to prevent breakage or to reduce noise or to solve an insulated blind spot as a cushioning material through the car insulating bushing 120 to improve the insulation performance.

FIG. 6 is a view showing an example in which the switchgear bushing structure according to the preferred embodiment of the present invention is integrally formed. FIG. 7 is a view illustrating an example in which the structure of the load switch breaker bushing structure according to the preferred embodiment of the present invention is assembled. Fig.

As described above, the opening and closing flow bushing structure 100 according to the present invention forms a primary housing structure by insulator molding for each individual component such as a built-in molded product VI (13), CT (14) It may correspond to a housing.

Next, a secondary housing structure for integrally insulator-molding each individual component of the first housed switchgear is formed, which corresponds to the outer housing 150, which will be described with reference to Figs. 6 and 7. Fig.

As shown in FIGS. 6 and 7, the switchgear bushing structure 100 according to the present invention has three outer housings 150, which are three phases, through an entire secondary insulation bushing 120 for internal components. And has a T-shape as a whole.

Referring to FIG. 6, the T-shaped outer housing 150 may be formed by integrally injecting the secondary insulation bushing 120.

Referring to FIG. 7, the secondary insulation bushing 120 is formed in an assembled state.

For example, the body of the outer housing 150 may be injection molded, and then a plurality of bushing needles 151, 152, and 153 may be sequentially inserted and assembled into the outer housing body. That is, a first bushing shoulder 151 having a cavity corresponding to the diameter of the body of the outer housing 150 and having a donut shape is inserted, and then a first bushing shoulder 151 A second bushing shoulder 152 having a hollow shape and having a donut shape and a third bushing cap 153 having the same shape as the second bushing cap are sequentially inserted and assembled. In addition, since it is three-phase, it can be largely formed by three outer housings 150 and can be assembled to have a T shape as a whole.

As a result, the molding operation time is long and the defect rate is very high at the time of forming the conventional epoxy bushing, so that the problem of the cost increase can be reduced as shown in FIG.

As described above, the technical ideas described in the embodiments of the present invention can be implemented independently of each other, and can be implemented in combination with each other. While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. It is possible. Accordingly, the technical scope of the present invention should be determined by the appended claims.

110: primary insulation bushing 111: output terminal connection part
120: tertiary insulated bushing 112: input terminal connection
130: Secondary insulation bushing
151, 152, 153: bushing god

Claims (7)

In the switch bushing structure,
Forming a VI insulated bushing in the form of a cylinder that covers the embedded molded part VI,
The VI insulating bushing has an input terminal connection part connected to the lead-in electrode as an input terminal on the upper surface, an output terminal connection part connected to the lead-out electrode as an output terminal on one side,
Wherein the input terminal connection portion and the output terminal connection portion are formed in a hole shape having a predetermined diameter sized to receive the lead-in electrode or lead-out electrode, Forming an input terminal insulated bushing of an elastic member to form a primary housing structure,
And a second housing structure for integrally forming an insulation body together with the primary housing structure,
Wherein the body is integrally formed in the secondary housing structure, and then a plurality of bushings, which are separately injected, are assembled into the body sequentially. The method according to claim 1,
Wherein the material of the VI insulated bushing is FRP. The method according to claim 1,
Wherein the material of the secondary housing structure is EPDM rubber or polymer rubber. The method according to claim 1,
The input terminal insulated bushing may have a structure capable of covering both the input terminal connection portion and the output terminal connection portion, and may have a cylindrical or concentric multi-stage cylindrical shape having two or more different diameters Wherein the bushing structure is formed of a metal material. The method according to claim 1,
The bushing cap includes a first bushing cap having a hollow shape corresponding to a diameter of the body and having a donut shape. The first bushing cap has a cavity formed at one side of the first bushing cap, And a third bushing shade of the same shape as the second bushing shade are sequentially fitted and assembled. delete delete

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