WO2013078681A1

WO2013078681A1 - Composite insulator and use thereof

Info

Publication number: WO2013078681A1
Application number: PCT/CN2011/083385
Authority: WO
Inventors: Chun Li; Jiansheng Chen; Huigang Sun
Original assignee: ABB Research Ltd Switzerland
Current assignee: ABB Research Ltd Switzerland
Priority date: 2011-12-02
Filing date: 2011-12-02
Publication date: 2013-06-06
Anticipated expiration: 2014-06-02

Abstract

A composite insulator and the use thereof. The composite insulator comprises an insulator tube (201) which is made of thermoplastic material. Compared with the traditional composite insulator, the processing of the composite insulator is much simpler and more cost-efficient, and the output rate thereof is substantially improved. Additionally, the composite insulator is more environment-friendly due to its good recyclability.

Description

A COMPOSITE INSULATOR AND USE THEREOF

TECHNICAL FIELD

[0001] The present invention relates to the field of a high voltage technology, and more particularly, relates to a composite insulation and use thereof. BACKGROUND

[0002] A composite insulator is a common insulating component wildly used for the electrical equipment such as the bushing for the transformers, the circuit breakers, the instrument transformers, the power transformers, the cable terminations, the surge arresters, the gas insulated switchgear (GIS) and so on. The composite insulator can be designed for high voltage application both in outdoor service and indoor service.

[0003] A traditional composite insulator is illustrated in Fig. 1A and 1 B. As illustrated, the composite insulator 100 generally comp ses an insulation tube 101 for bearing mechanical loads and elastic sheds 102 for a purpose of protection. Additionally, the composite insulator 100 also comp ses metal end fittings 103, 104 respectively provided at each end thereof for connecting to other devices. The insulation tube 102 is hollow, which can be seen from Fig. 1 B, for a conductor running therethrough. Normally, the insulation tube 102 is made of, for example, glass fiber-reinforced plastics (GFRP), the sheds are made of elastic material such as silicone rubber, and the metal end fittings are made of for example aluminum.

[0004] Additionally, it is well-known that epoxy resin has advantages of high electrical stresses and reliable mechanical performance and thus, in the prior art the epoxy resin is usually used as the matrix system for the insulation tube. The main processing approach of GFRP is wet filament winding technique where the continuous fibers are drawn through a bath of epoxy resin and then wound onto a mandrel at a controlled pre-stress. However, such a processing is extremely complex and costly, and moreover the output rate is very low.

[0005] Therefore, there is a need for an improved composite insulator in the art.

SUMMARY OF THE INVENTION

[0006] In view of the foregoing, the present invention has proposed a solution for improving the composite insulator in the art so as to solve or at least partially mitigate at least a part of problems in the prior art.

[0007] According to an aspect of present invention, there is provided a new composite insulator. The composite insulator comprises an insulation tube, wherein the insulation tube is made of thermoplastic material. [0008] In an embodiment of the present invention, the thermoplastic material can be fiber reinforced thermoplastic material. The fiber reinforced thermoplastic material can have a content of fiber not more than 70%. Preferably, it can have a content of about 15% to 45% fiber, and more preferably about 20% to 35% fiber.

[0009] In another embodiment of the present invention, the fiber can be short fiber or milled fiber or mixture of the short fiber and the milled fiber.

[0010] In a further embodiment of the present invention, the fiber can comprise any one of glass fiber, boron fiber, ceramic fiber, quartz fiber and basalt fiber or any combination thereof.

[0011] In a still further embodiment of the present invention, the thermoplastic material can comprise engineering plastics or high performance engineering plastics.

[0012] In a yet further embodiment of the present invention, the thermoplastic material can comprise any one of polyethylene terephthalate, polybutylene terephthalate, polytri methylene terephthalate, polyoxymethylene, polycarbonate, polysulfone, polyamide, aromafic polyamides, polyetheretherketone, polyphenylene oxide, polyphenylene sulfide, polyarylsulfone, polyethersulfone, and polyetherimide or any combination thereof.

[0013] According to a second aspect of the present invention, there is provided use of a composite insulator according to the first aspect as set forth hereinabove in bushing for transformers, circuit breaker, instrument transformer, power transformer, cable termination, surge arresters, and gas insulated switchgear.

[0014] Compared with the traditional composite insulator with thermoset material insulation tube, the processing of the composite insulator as provided in the present invention is much simpler and more cost-efficient, and the output rate thereof is substantially improved. Additionally, the composite insulator of the present invention is more environment-friendly due to its good recyclability.

BRIEF DESCRIPTION OF THE DRAWINGS [0015] The above and other features of the present invention will become more apparent through detailed explanation on the embodiments as illustrated in the embodiments with reference to the accompanying drawings. Like reference numbers represent same or similar components throughout the accompanying drawings of the present invention, wherein:

[0016] Fig. 1 A schematically illustrates a composite insulator in the prior art.

[0017] Fig. 1 B schematically illustrates a partial sectional view of the composite insulator in

Fig. 1A.

[0018] Fig. 2 schematically illustrates a composite insulator according to an embodiment of the present invention. DETAILED DESCRIPTION OF EMBODIMENTS

[0019] Hereinafter, a new composite insulator as provided in the present invention will be described in detail through embodiments with reference to the accompanying drawings. It should be understood that these embodiments are presented only to enable those skilled in the art to better understand and implement the present invention, not intend for limiting the scope of the present invention in any manner. Additionally, it should be also noted that the wording "a/an" as used herein does not exclude a plurality of such steps, units, devices, and objects, and etc.

[0020] In the present invention, the inventors have proposed a new composite insulator. As illustrated in Fig. 2, similarly to the insulator in the prior art as shown in Figs. 1 A and 1 B, the composite insulator comprises an insulation tube 201 for bearing mechanical loads, elastic sheds 202 for a purpose of protection and metal end fittings 203, 204 respectively provided at each end of the composite insulator; however, the insulation tube 201 has used a different material, i.e. thermoplastic material to replace with the o ginal glass fiber reinforced epoxy resin used in the prior art.

[0021] For some application, the thermoplastic material should have a higher elastic modulus to provide the required mechanical properties and keep a small deflection for the insulator. It is known that the insulation tube will support the hollow insulator to resist outside loads, e.g. bending, vibration and etc., and thus the mechanical property is a key performance indicator for the composite insulator. Besides, it is also important to keep a small deflection for the insulation tube. Therefore, a higher elastic modulus is a critical requirement. However, for some other application, the requirement of the elastic modulus is very low and the thermoplastic material such as any engineering plastics and high performance engineering plastics can satisfy the requirement.

[0022] In embodiments of the present i nvention, it can use fiber reinforced thermoplastic material to provide the enough elastic modulus. The fiber reinforced thermoplastic material is a kind of thermoplastic material which is reinforced with fibers. The fiber generally has a high elastic modulus, low deformation under pressure and a high intensity, and thus adding fiber into the thermoplastic material will enhance toughness of the thermoplastic material, which made the reinforced thermoplastic material much more suitable for the insulation tube. The fiber added into the thermoplastic material can be in any suitable form, however, the short fiber or milled fiber is preferable. The short fiber can also be called as cut fiber, and can be obtained by for example cutting or pulling apart the long fiber bundle. The milled fiber, i.e., the fiber power, is obtained by milling the fiber into power. The suitable fiber can be glass fiber, boron fi ber, ceramic fiber, quartz fiber, basalt fiber or any combination thereof.

[0023] To make the insulation tube, the fiber added into the thermoplastic material can be not more than about 70%. The more the fiber is, the greater reinforcement to the thermoplastic it will provide; however, too many fiber might result in a failure to form the insulation tube and thus generally not more than 70% fiber is suitable. It should be noted that, for different applications, the proper content of fiber might be different. Generally speaking, a small size of insulator will require a low fiber content and the large size of i nsulator will require a high fiber content. However, in the present invention, it is preferable if the fiber reinforced thermoplastic material can have about 15% to 45% of fiber, in such a way, the insulation tube will have a better performance. Additionally, 20% to 35% fiber in the fiber reinforced will be more preferable.

[0024] The thermoplastic material can be any proper thermoplastic material which can provide enough stiffness to product the insulation tube. The thermoplastic material used to product the insulation tube could be engineering plastics or high performance engineering plastics and particularly, it can be any one of polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyoxymethylene, polycarbonate, polysulfone, polyamide, aromafic polyamides, polyetheretherketone, polyphenylene oxide, polyphenylene sulfide, polyarylsulfone, polyethersulfone, and polyetherimide or any combination thereof.

[0025] Additionally, due to the fact that the insulation tube will be made of thermoplastics material, the insulation tube can be made by any suitable molding method such as extrusion molding, injection molding and the like. Compared with the convention processing (i.e., wet filament winding technique) of the glass reinforced epoxy resin tube, the processing of the thermoplastic tube can be much simpler and thus more efficiently for tube products.

[0026] Furthermore, the thermoplastic material has a better recyclability than the epoxy resin. The epoxy resin as a kind of thermosets is not recycled currently to a great extent since it belongs to the cross-link structure and cannot be melted and the current recycling is only restricted to milling and using the milled power as filler. Hence, replacing the GFRP tube with thermoplastic tube could make power products much friendlier for the environment.

[0027] Therefore, the processing of the composite insulator as provided in the present invention can be much simpler and more cost-efficient, and the output rate thereof can be substantially improved. Additionally, the composite insulator of the present invention is more environment-friendly due to its good recyclability.

[0028] By far, the present invention has been described with reference to the accompanying drawings through particular preferred embodiments. However, it should be noted that the present invention is not limited to the illustrated and provided particular embodiments, but various modification may be made within the scope of the present invention.

[0029] Though the present invention has been described with reference to the currently considered embodiments, it should be appreciated that the present invention is not limited the disclosed embodiments. On the contrary, the present invention is intended to cover various modifications and equivalent arrangements falling within in the spirit and scope of the appended claims. The scope of the appended claims is accorded with broadest explanations and covers all such modifications and equivalent structures and functions.

Claims

1 . A composite insulator comprising an insulation tube, wherein the insulation tube is made of thermoplastic material

2. A composite insulator according to claim 1 , wherein the thermoplastic material is fiber reinforced thermoplastic material.

3. A composite insulator according to claim 2, wherein the fiber reinforced thermoplastic material has a content of fiber not more than about 70%.

4. A composite insulator according to claim 3, wherein the fiber reinforced thermoplastic material has a content of about 15% to 45% fiber.

5. A composite insulator according to claim 4, wherein the fiber reinforced thermoplastic material has a content of about 20% to 35% fiber.

6. A composite insulator according to claim 2, wherein the fiber is short fiber or milled fiberor mixture of the short fiber and the milled fiber.

7. A composite insulator according to claim 2, wherein the fiber comprises any one of glass fiber, boron fiber, ceramic fiber, quartz fiber and basalt fi ber or any combination thereof.

8. A composite insulator according to claim 1 , wherein the thermoplastic material comprises engineering plastics or high performance engineering plastics.

9. A composite insulator according to claim 8, wherein the thermoplastic material comprises any one of polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyoxymethylene, polycarbonate, polysulfone, polyamide, aromafic polyamides, polyetheretherketone, polyphenylene oxide , polyphenylene sulfide, polyarylsulfone, polyethersulfone, and polyetherimide or any combination thereof. .

10. Use of a composite insulator according to any one of claims 1 to 9 in bushing for transformers, circuit breakers, instrument transformers, power transformers, cable terminations, surge arresters, or gas insulated switchgear.