RU2747578C2 - Method of manufacturing polymer insulator of overhead power lines - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: invention relates to a device and a method for manufacturing electric basalt-plastic insulators for overhead power lines. The insulator consists of a bearing element made of basalt roving impregnated with a binder, two s and a shell, while the bearing element is made in the form of a two-layer bundle twisted from a continuous basalt roving, laid around the end fittings. The method of manufacturing the insulator is characterized by the fact that the impregnated continuous basalt roving is laid around the end fittings, sequentially forming the inner and outer layers of the bundle of the required length and thickness, then the inner layer is twisted and the layers are twisted together.

EFFECT: invention makes it possible to increase reliability of the insulator, tracking resistance and its strength along the entire length of the bearing element, as well as to increase the manufacturability of its manufacture.

1 cl, 1 dwg

Description

The invention relates to electrical engineering, and in particular to a device and method for manufacturing electrical basalt-plastic insulators used in overhead power lines.

The applicant's analysis of the state of the art has shown that techniques are known in the art for manufacturing electrical insulators from high-strength composite materials and insulators obtained by these methods (RF patents No. 2233492, 2119689, etc.).

Known electrical insulator (RF patent No. 2233492, published July 27, 2004), consisting of a fiberglass rod and an insulating element, which is used as an elastomer (silicone rubber). However, it does not have such high physical and mechanical characteristics, requires expensive equipment and significant energy costs, as well as multi-stage.

Also known is an electrical insulator based on glass fiber (patent No. 2119689, published September 27, 1998). Bushings are inserted into the body of the insulator to provide increased resistance to torsion during the manufacturing process. The disadvantage of this method is the design, which implies increased strength characteristics at one of the ends of the insulator.

The closest of the known solutions in terms of the technical essence and purpose is an electrical insulator and a method for its production according to the patent of the Russian Federation No. 2118005. The design of the insulator includes a bearing element, an end piece and a shell. The known electrical insulator contains a support element made of fiberglass impregnated with a binder, two end fittings and a shell. In this case, the supporting element is made in the form of a two-layer bundle, twisted from a continuous strand of fiberglass, laid around the end piece, and the inner and outer layers are twisted in the opposite direction relative to each other. The method of manufacturing this electrical insulator includes impregnating a strand of unidirectional glass fiber with a binder, forming a carrier, curing the binder, and applying a sheath. The formation of the carrier element is carried out by laying a continuous strand of glass fiber impregnated with a binder around the end piece, sequentially forming the inner and outer layers of the bundle of the required length and thickness. Next, the inner layer is twisted, the outer layer is applied to it, and the layers are simultaneously twisted in the opposite direction, followed by axial stretching of the carrier element.

The known method does not allow achieving high strength characteristics of the insulator, because its implementation causes an unequal structure to be obtained, since the number of strands forming the carrier rod is twice the number of strands laid around each of the end fittings. Accordingly, the cross-sectional area of the formed support rod will be twice the cross-sectional area of the fiberglass layer laid around each of the end fittings, i.e. the mechanical strength of fiberglass, laid around the end fittings, is at least two times less than the mechanical strength of the supporting fiberglass rod, which reduces the strength of the structure as a whole. In addition, when the fiberglass is laid, voids are formed, as a result of which the finished fiberglass is obtained inhomogeneous, which reduces the strength of the insulator and the reliability of the carrier, and the steel end with a protective shell is an additional source of concern. The insulator manufacturing process is multi-stage and energy-intensive.

The technical problem of the present invention is the need to create a high-voltage electrical insulator with increased reliability, tracking resistance and its strength along the entire length of the bearing element, especially in the places where it is attached to the end fittings and their replacement with high-strength polymer analogs with the ability to control the diameter of the inner hole of the bushing, as well as to simplify the production process and reduce its energy consumption. To solve this problem, an electrical insulator device and a method for its manufacture are proposed.

The invention is illustrated by drawings: FIG. - device of a polymer insulator for overhead power lines. Positions in the drawings designate: 1 - bearing element; 2 - end piece; 3 - shell; 4 - inner layer; 5 - outer layer.

The insulator includes a carrier (1), end fittings (2) and a sheath (3). The supporting element is made in the form of a bundle of basalt roving, which has an inner (4) and outer (5) layers. Terminals are in the form of a sleeve or coil. The casing is made of rubber or thermoplastic.

The insulator is made as follows.

Roving from basalt fiber TU 5952-008-13070083-2009 in the form of a strand is impregnated with an epoxy binder mixed with a cold curing hardener PEPA and wound around the end fittings (2), forming first the inner layer (4), and then the outer layer (5) of a bundle in the form closed chords of the required length and cross-section. The inner layer (4) is twisted in one direction, then the outer layer (5) is applied to it and joint twisting in the opposite direction, by rotating the end fittings relative to each other. Further, the end fittings are fixed in clamps and stretched in the axial direction under a load depending on the diameter of the resulting insulators; in this state, curing takes place within 24 hours.

The insulator made in this way, having a size of 250 mm and a cross-section of 10 mm, has an electrical strength of 50 kV / cm and a tensile strength of 80 kN, which significantly exceeds the performance of analogs. It is possible to derive a dependence on an increase in the cross-section by ~ 0.8% and a decrease in the length of the insulator by ~ 0.4% per twisting of the thread (within 15 twists).

Thus, the proposed insulator has high strength and electrical insulating properties, high manufacturability, extended service life, as well as the ability to control the inner diameter of the sleeve. This allows them to be used for work at substations, on overhead power lines and overhead contact networks of electric transport.

Claims (1)

A method of manufacturing an insulator for overhead power lines, which consists in impregnating a roving made of basalt fiber in the form of a strand with an epoxy binder mixed with a cold curing hardener PEPA, and wound around the end fittings, forming first an inner layer and then an outer layer of a bundle in the form of closed belts of the required length and cross-section; then, the inner layer is twisted in one direction, then the outer layer is applied thereon and jointly twisted in the opposite direction by rotating the end fittings relative to each other; then, the obtained support element is stretched in the axial direction and cured in this state.

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