RU2722921C2 - High-voltage suspended insulator - Google Patents

Abstract

FIELD: electricity.SUBSTANCE: invention relates to the field of power engineering, in particular to the designs of high-voltage suspension insulators used in construction of overhead power transmission lines. Insulator consists of metal cap 1, rod 2, insulating part 3 interconnected by cement-sand binder 4, and dielectric element 5 in external zone 6 of rod 2 sealing. Significant reduction (at least 30 %) of maximum intensity of electric field on external side of sealing of rod 2 is achieved at thickness of dielectric element of 5 Δθ≥(2÷8) mm.EFFECT: tests of insulators showed significant reduction of radio interference levels, possibility of increasing allowable voltage for standardized level of radio interference equal to 86 dB (GOST 6490-2017), not less than (30÷50) %.6 cl, 2 dwg

Description

The invention relates to the field of electric power, in particular to the construction of high-voltage suspension insulators used in the construction of overhead power lines.

It is known that a high-voltage suspension insulator, for example, of a plate type, consisting of a metal cap, a rod and an insulating part interconnected by a cement-sand bond, is a source of radio interference caused by electrical discharges in the air (corona discharges) at the end of the cap and on the side of the rod in the zone of its incorporation with a cement-sand bond. Moreover, at relatively low voltages, the levels of emitted interference are determined by the coronation processes on the side of the end face of the insulator cap, and as the voltage increases, the levels of radio noise are practically determined by the coronation intensity from the side of the rod termination at the cement-sand bond - insulating part - air boundary.

Known high-voltage suspension insulator containing a disk-shaped insulating part with a head, the surface of which is coated with a moisture-resistant coating, metal reinforcement in the form of a rod and caps connected to the insulating part using a bundle, characterized in that in order to increase mechanical strength and operational reliability, a moisture-resistant coating is applied on the surface of the head of the insulating part in the zones of its interaction with the metal reinforcement of the insulator [1].

This well-known high-voltage suspension insulator is characterized by a high level of radio interference, since different sections of the cement-sand ligament have different potentials, which leads to electrical discharges on the surface of the cement-sand ligament during operation.

The closest technical solution to the proposed one is a high-voltage suspended insulator, consisting of a metal cap, rod and insulating part, interconnected by a cement-sand bond [2].

In this technical solution, a decrease in the level of radio noise is achieved by optimizing the configuration of the cap, for which purpose an annular protrusion facing the plate of the insulating part is made on the open end of the latter, one of the walls of which coincides with the inner surface of the cap. However, the level of radio noise reduction of this known insulator is insufficient when it is used on overhead power lines, power substations, distribution networks and other electric power facilities of a similar purpose, due to the potential difference between the sections of the cement-sand bond, which causes electric discharges, which ultimately destroy the insulators .

The applicant set himself a practical task, namely, to develop and widely introduce high-voltage suspension insulators into electric grid construction practice, which are characterized by high levels of radio noise by leveling the electric field on the outer core sealing area. The above-mentioned positive technical result was achieved due to the combination of essential features of the high-voltage suspension insulator made according to the present invention, presented in the following claims: “high-voltage suspended insulator, consisting of a metal cap, rod and insulating part, interconnected by a cement-sand bond; at least one dielectric 3 element with a thickness of at least Δθ≥ (2 ÷ 8) mm and a specific resistance of at least ρ≥10 ⁷ Ohm⋅m is installed on the outer layer of the cement-sand ligament in the core embedding zone; the dielectric element is made by pouring a silicone sealant in a liquid state, followed by hardening; the dielectric element is installed by gluing it with silicone sealant; the dielectric element is made of a single component substance; the dielectric element is made of a multicomponent substance; the dielectric element is made of a multilayer of various materials. "

The invention is illustrated by drawings, where in FIG. 1 is a fragmentary view of a high voltage suspension insulator made in accordance with the present invention; in FIG. 2 is the same as in FIG. 1, a generalized result of numerical studies of electric fields in the form of dependences of the maximum intensity in the outer zone of the rod embedment on the thickness of the dielectric element.

The inventive high-voltage suspension insulator, for example, of a plate type, consists of a metal cap 1, a rod 2, an insulating part 3, interconnected by a cement-sand bond 4, and a dielectric element 5 in the outer zone 6 of the core 2.

In FIG. Figure 2 shows the generalized result of numerical studies of the electric fields of high-voltage plate-shaped suspension insulators in the form of dependences of the maximum tension in the outer zone 6 of the rod 2 termination on the thickness of the dielectric element 5 with a specific layer resistance of at least ρ≥10 ⁷ Ohm⋅ for an “light” class insulator with mechanical force - 70 kN and the "heavy" class in mechanical strength - 210 kN. An analysis of these numerical studies shows that a significant decrease (at least 30%) in the maximum electric field strength on the outside of the rod 2 termination is achieved with a thickness of the dielectric element 5 Δθ≥ (2 ÷ 8) mm.

The dielectric element 5 is made by pouring a silicone sealant in a liquid state, followed by hardening. In addition, the dielectric element 5 can be installed by gluing it with silicone sealant, and can also be made of a single-component substance or of a multi-component substance, for example, multilayer of various materials.

The invention works as follows:

The implementation of the invention is carried out in the following sequence. The assembly of insulators is carried out in a known manner, but taking into account the replacement of the upper layer of cement-sand ligaments in the core sealing zone with a dielectric element. After the hardening process of the bond according to the existing technology, a dielectric element is created by pouring in a liquid state, for example, cold-hardened silicone in the intended area in the core sealing zone. The dielectric layer can be formed by bonding a prefabricated product using silicone sealant.

Tests of insulators manufactured in accordance with the proposed invention showed a significant decrease in radio noise levels, the possibility of increasing the permissible voltage for a normalized level of radio noise equal to 86 dB (GOST 6490-2017), not less than (30 ÷ 50)%.

Sources of information

[1]. Description of the invention to USSR author's certificate No. 1619957 "High-voltage suspension insulator", НВВ 17/02, claimed 05.07.1998, published 10.09.1995.

[2]. Description of the invention to patent No. 1475399 "High-voltage pendant type insulator", НВВ 17/02, claimed June 30, 1993, published.

[3]. Description of the invention to USSR author's certificate No. 1644667 "High-voltage pendant insulator", НВВ 17/02, claimed January 3, 1989, published July 25, 1995.

[4]. Description of the invention to USSR author's certificate No. 1579303 "High-voltage suspended insulator", НВВ 17/02, claimed on 10/31/1998, published on 08/20/1995.

[5]. US patent No. 5147984 "High-voltage suspension insulator", H01B 17/02, published 1992.

[6]. Description of the invention to patent No. 2297056 "High-voltage suspension insulator", НВВ 17/02, claimed on April 14, 2006, published on April 10, 2007.

[7]. Utility Model Patent No. 86036 “Linear Suspension Insulator”, Н01В 17/02, filed May 4, 2009, published August 20, 2009.

[8]. Utility Model Patent No. 88198, “Garland of a Linear Hanging Poppet Insulator,” Н01В 17/02, filed June 30, 2009, published October 27, 2009.

[9]. Description of the invention to patent No. 2454746 "Linear suspension insulator", Н01В 17/00, claimed on 02.25.2011, published on 27.06.2012.

[10]. Description of the invention to patent No. 2491672 "High-voltage suspended insulator", Н01В 17/02, claimed 02.25.2011, published 08.28.2013.

[eleven]. Utility Model Patent No. 75500 “Suspension Insulator”, Н01В 17/00, filed April 4, 2008, published.

Claims (6)

1. A high-voltage suspended insulator consisting of a metal cap, a rod and an insulating part interconnected by a cement-sand bond, characterized in that at least one dielectric element with a thickness of at least Δθ is installed on the outer layer of the cement-sand bond ≥ (2 ÷ 8) mm and specific resistance not less than ρ≥10 ⁷ Ohm⋅m. 2. The insulator according to claim 1, characterized in that the dielectric element is made by pouring a silicone sealant in a liquid state with subsequent hardening. 3. The insulator according to claim 1, characterized in that the dielectric element is installed by gluing it with silicone sealant. 4. The insulator according to claim 1, characterized in that the dielectric element is made of a single-component substance. 5. The insulator according to claim 1, characterized in that the dielectric element is made of a multicomponent substance. 6. The insulator according to claim 5, characterized in that the dielectric element is made of a multilayer of various materials.

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