INSULATOR FOR ELECTRICAL OVERHEAD LINES WITH A MECHANICAL LOAD DETECTION DEVICE

Description

Domaine technique

[0001] The field of the invention is that of insulators for medium, high and very high voltage power lines.

[0002] The invention relates in particular to a hood / rod type electrical insulator comprising a dielectric element having a skirt-shaped outer surface and which is extended by a metal hood on one side and a metal rod on the other.

[0003] It can be an insulator with dielectric elements, for example, made of tempered glass, porcelain or ceramic, of the hood and rod type (hood / rod) which are assembled in a chain.

[0004] It could also be a rigid barrel insulator with porcelain or ceramic dielectric elements.

[0005] These insulators can be mounted in suspension or anchored on a pylon to support a medium, high or very high voltage power line in the air.

[0006] As is well known, electrical suspension insulators, more specifically so-called hood / stem insulators such as insulator 1 illustrated on the figures 1A et 1B , may include an insulating skirt 2 made of a dielectric material, a metal hood 4 with a top and a base, the metal hood 4 having an upper part 4' having a recess (T) and a lower part 4" having a cavity open towards the base of the metal hood 4. The recess (T) has a lateral opening extending to the top of the metal hood (4).

[0007] An upper part 3 of the skirt 2 is housed in the cavity of the metal hood 4. The upper part 3 of the skirt 2 is connected to the metal hood 4 by a sealing element 5 (cement or mortar).

[0008] A first end of a metal rod 6 is connected by this same sealing element 5 in a cavity 7 of the skirt inside the upper part 3 of the skirt 2.

[0009] As is known, such suspension electrical insulators are designed to be connected in series by inserting a second free end of the metal rod 6 of one electrical insulator into the recess (T) in the upper part 4' of the metal cover 4 of an adjacent electrical insulator to form an insulating chain of insulators. This chain of insulators is thus capable of holding electrical cables in horizontal (anchoring) or vertical (suspension) tension in the air for suspension from a pylon (P) for medium, high, and very high voltage overhead power lines (E), as illustrated in the figures 2A And 2B . Technique antérieure

[0010] It is known that insulators for overhead power lines can be subjected to very severe climatic and mechanical conditions.

[0011] For example, it is known that these insulators can be subjected to undesirable mechanical stresses representing an excessive mechanical load exerted by the appearance of a mass during, for example, the formation of ice at the level of the conductors of the power line or of the hood / rod insulators constituting the insulator chains or following the accumulation of snow at the level of the conductors of the power line.

[0012] When such a mass becomes too large, there is a risk of the pylon or any other element of the line (conductor, metal accessory, etc.) breaking, creating permanent damage to the line and thus causing an interruption of the power supply.

[0013] In the context of electrical network monitoring, it is already known to integrate a detection device, such as a surface leakage current detection device on glass or porcelain chain insulators of the hood / rod type to detect and measure surface leakage currents on this type of installation as described in document EP 2884292 or document EP3312622.

[0014] Document WO 2022 / 123509A1 relates to an anchoring system for overhead power lines, equipped with a measuring instrument.

[0015] Document JP 2000 276957 A relates to an overhead line insulator indicating deterioration.

[0016] Document CN 107 424 691 A relates to an isolator preventing fractures.

[0017] US document 2018 / 106846 A1 relates to an insulator for overhead power lines with a protected leakage current detector.

[0018] Document CN 206 163 204 U relates to a suspension insulator and a transmission line.

[0019] US document 5 568 132 A relates to a load isolator, intended to electrically isolate a crane from the load it lifts and possibly equipped with load sensors.

[0020] Power line operators would like to be able to perform additional measurements directly on an insulator in order to improve power line monitoring and intervene even before a potential power outage due to a fault on the lines occurs. They also want to be able to detect mechanical overloads before irreversible deformation of mechanical parts occurs.

[0021] As part of the monitoring of overhead power line installations in cold and humid regions, but not only, insulator manufacturers and more broadly equipment manufacturers, as well as operators, are therefore seeking to develop new monitoring methods. Exposé de l'invention

[0022] The aim of the invention is therefore to provide an insulator for overhead power lines equipped with a mechanical load detection device in order to allow remote monitoring of overhead power line installations.

[0023] For this purpose, the invention relates to a hood / rod type insulator according to independent claim 1.

[0024] The insulator according to the invention may have the following characteristics: at least one strain gauge may be glued to the outer surface of the upper part of the metal cover; the load sensing device may further include a data transmission device capable of recording in computer memory representative values ​​of mechanical loads measured by at least one mechanical sensor consisting of at least one strain gauge and associated with an electronic conditioner, and of transmitting data to a station remote from the insulator; the load sensing device may include a protective element for at least one strain gauge; the load sensing device may include several strain gauges fixed to the metal cover of the insulator and preferably at the outer surface of the upper part of the metal cover; the dielectric element may be made of glass, porcelain or ceramic.

[0025] The basic idea of ​​the invention is to place at least one strain gauge on an insulator at the top of the metal cover, which has a recess forming a housing for a metal rod (or a metal attachment bracket). It is at this top of the metal cover, where the metal rod of an adjacent insulator is inserted, that the maximum mechanical (micro)deformations can occur, the deformations being linked to mechanical stresses representative of a mechanical load exerted on the overhead power line.

[0026] Results of mechanical deformation measurements by the mechanical load detection device can be sent by any type of communication mode to a power line monitoring station of an electrical network.

[0027] In the event of measurements of mechanical deformations exceeding a predefined threshold on an overhead power line, information including a monitoring alert signal may be sent to warn an operator of the possible overload of the power line in question and the risk of failure if no action is taken by the operator.

[0028] The mechanical load detection device of the insulator according to the invention can be arranged to manage its behavior in an event-driven manner, that is to say by taking into account the evolution of the measurement of mechanical deformations exerted at the level of the power line and / or according to external conditions.

[0029] The insulator according to the invention is generally the first insulator (pylon side) of a chain of insulators, the one closest to the pylon and which serves as an anchor for the chain of insulators to the pylon. Description sommaire des dessins

[0030] The present invention will be better understood and other advantages will become apparent upon reading the following description and the accompanying drawings, in which: [ Fig. 1A ] ] Fig.1B ] there [ Fig.1A ] is a schematic illustration of an insulator according to the invention of the hood / rod type and the [ Fig.1B ] shows an axial cross-sectional view of the insulator of the [ Fig.1A ] ; ] Fig.2A ] ] Fig.2B ] there [ Fig.2A ] is a schematic illustration of a chain of suspension insulators with dielectric elements assembled in series and the [ Fig.2B ] is a schematic illustration of a chain of insulators of the type of the [ Fig.2A ] installed on a pylon and which supports a medium, high or very high voltage overhead power line to the pylon; Fig.3A ] ] Fig.3B ] ] Fig.3C ] ] Fig.3D ] ] Fig.3E ] THE figures 3A , 3B , 3C , 3D et 3E are schematic illustrations of an insulator according to the invention to be equipped with one or more strain gauges on the metal cover of the insulator; Fig.4 ] - there [ Fig.4 ] is a schematic illustration of an insulator according to the invention equipped with several strain gauges; [ Fig.5A ] ] Fig.5B ] THE figures 5A And 5B are illustrations of an insulator according to the invention using a clevis-tenon fastening system. Description des modes de réalisation

[0031] THE figures 1A, 1B , 2A And 2B were previously discussed.

[0032] An overhead power line hood / rod type insulator 1 comprises an end dielectric element of glass, porcelain or ceramic, having an outer surface in the form of a skirt 2 and which is extended by a galvanized cast iron metal hood 4 on one first side of the insulator 1 and a metal rod 6 on a second side of the insulator 1 opposite the first side.

[0033] As already seen, such electrical suspension insulators are assembled together in series by fitting the free end of the metal rod 6 of an electrical insulator (or a metal hanging armature) into the recess T of the cylindrical upper part 4' of the metal hood 4 of an adjacent electrical insulator.

[0034] An insulator 1 with its skirt 2, its metal cover 4 and its metal rod 6, is illustrated in several views on the figures 3A à 3E As seen on the [ Fig.3A The recess T is in the form of a lateral opening in the upper part 4' of the metal cover 4 and here has a shape complementary to the free end of the metal rod 6 (or a shape complementary to a metal attachment bracket). This recess T has, on the top of the upper part 4' of the metal cover 4, a retaining collar for the tension of the metal rod 6 or the metal attachment bracket.

[0035] Generally, to hold the metal rod 6 in the recess T or the metal hanging frame, a pin is inserted into a pin hole T' arranged through the upper part 4' of the metal cover 4 and opening into the recess T.

[0036] A pin hole T' is arranged on the circumference of the upper part 4' of the metal cover 4 and opens into the recess T for the passage of a locking pin for the metal rod 6 in the upper part 4'. This pin hole T' is visible on the figures 3A And 3B . Here the pin hole T' is positioned opposite to the lateral opening.

[0037] To detect mechanical stresses representative of a mechanical load exerted on the power line, the insulator according to the invention includes a mechanical load detection device. This device comprises one or more strain gauges C (sometimes also called strain gauges) fixed to the metal cover 4 of the insulator 1. Preferably, the strain gauge(s) are fixed to the outer surface of the circumference of the upper part 4' of the metal cover 4, in the areas illustrated by dashed frames around the recess on the figures 3A à 3D but can also be fixed to the outer surface of the top of the upper part 4' of the metal cover 4 in the areas shown by dotted frames as illustrated on the [ Fig.3E ].

[0038] Preferably, the strain gauge(s) are glued to the upper part 4' of the metal cover 4, in areas where the galvanized surface of the metal cover 4 has been smoothed either by sanding the galvanized surface or by adding a layer (such as glue or resin) to the galvanized surface. Any other known means of fixing the strain gauge(s) may be considered. The [ Fig.4 ] illustrates by an example where three strain gauges are fixed on the upper part 4' of the metal hood 4, one strain gauge being fixed on the outer surface of its top and two strain gauges being fixed on the outer surface of its circumference.

[0039] The load-sensing device further includes a data transmission device Tr represented in [ Fig.4 ]. This data transmission device is capable of recording in computer memory representative values ​​of mechanical loads measured by one or more strain sensors (not shown) (each strain sensor consisting of one or more strain gauges associated with an electronic conditioner Cond) and of transmitting the data to a remote station (not shown) from the isolator.

[0040] The mechanical load level can be measured continuously or discretely by the insulator equipped with its sensor(s) and the measurements can be sent regularly by the remote station by any type of communication mode to a power line monitoring station of an electrical network.

[0041] The level of mechanical load can also be measured continuously or discretely by the insulator equipped with its sensor(s). Only if a predetermined threshold is exceeded, indicating abnormal mechanical deformation at the metal cover (4) or mechanical load at the overhead line, can a monitoring alert signal be sent from the remote station, via any type of communication, to a power line monitoring station of an electrical network to notify the operator of the power line in question. The operator can then take the necessary measures based on the level of the alert received.

[0042] It is advantageous to protect the strain gauge(s) from the elements to limit their malfunction. Therefore, the load detection device includes a protective element (not shown) for the strain gauge(s). This protective element could be, for example, a sleeve made of a flexible, elastic, and electrically insulating material, such as silicone, which fits onto the metal cover 4 of the insulator 1. The protective element could also be, for example, a coating applied locally to the strain gauge(s), such as a resin or silicone coating.

[0043] Preferably, the insulator 1 according to the invention is the first insulator in a chain of insulators, the one closest to the pylon (P), and which serves as an anchor for the chain of insulators to the pylon. The metal cover 4 can be extended axially by a metal bracket for attaching the insulator 1 to the pylon P, this metal bracket having a free end similar to the free end of a metal insulator rod 6.

[0044] This invention also applies to insulators having attachments other than those detailed in this text. For example, it also applies to insulators whose metal reinforcements connect to each other by a clevis-and-tenon system as illustrated by the [ Fig.5A ], with an insulator 50 comprising a clevis 52 terminating a metal cap 4 partially covering a dielectric element skirt 2, a tenon 54 terminating the rod 6, and a fixing pin 56. In this case, the gauges would be glued to the base of the clevis and / or onto the clevis itself, for example at the levels indicated by Z in the [ Fig.5B ].

[0045] THE figures 5A And 5B include a perpendicular view A and a perpendicular view B of the tenon 54 and the clevis 52, respectively.

Claims

1. Insulator (1, 50) of the cap / rod type for overhead power lines, which insulator comprises a dielectric element having an outer surface in the form of a skirt (2) and being extended by a metal cap (4) at a first end of the insulator (1) and a metal rod (6) at a second end of the insulator (1) opposite the first end, and a mechanical load detection device having at least one strain gauge, said metal cap (4) comprising a cylindrical upper part (4') having a recess (T) intended to receive a metal rod (6) or a metal anchoring framework, the insulator being characterized in that the strain gauge (C) is fastened to said metal cap (4) of said insulator (1) so as to be used to detect mechanical strains representative of a mechanical load exerted on said power line, and in that said at least one strain gauge (C) is fastened to the outer surface of said upper part (4') of said metal cap (4).

2. Insulator (1, 50) according to claim 1, characterized in that said at least one strain gauge (C) is bonded to said outer surface of said upper part (4') of said metal cap (4).

3. Insulator (1, 50) according to either of claims 1 or 2, characterized in that said load detection device also comprises a data transmission device (Tr) capable of recording in computer memory values representative of mechanical loads measured by at least one mechanical sensor consisting of said at least one strain gauge associated with an electronic conditioner (Cond) and capable of transmitting data to a station remote from the insulator (1).

4. Insulator (1, 50) according to any of the preceding claims, characterized in that said load detection device comprises a protective element for protecting said at least one strain gauge (C).

5. Insulator (1, 50) according to any of the preceding claims, characterized in that said load detection device comprises a plurality of strain gauges (C) fastened to said metal cap (4) of said insulator (1).

6. Insulator (1, 50) according to any of the preceding claims, characterized in that said dielectric element is made of glass, porcelain or ceramic.