FR2501408A1 - Electric cable servicing structure - has motor driven telescopic conducting pole providing connection to overhead HT cable - Google Patents

Abstract

The telescopic structure includes a base support unit (1) comprising several pillars holding a horizontal platform. An insulating column (12) stands on this platform and is held up by insulating cables (13). A series of metal telescopic elements (14A-N) are mounted on top of the indulating column, in order to establish a connection between the overhead cable and a terminal point (16). A motor (20) in the base unit has drive belts (31,32) linked to the telescopic column in order to raise and lower it. The motor may also be rotated manually in case of a failure, providing an advantage over otheother pneumatic systems.

Description

Telescopic disconnector
The present invention relates to a telescopic disconnector which can in particular be used to connect to an overhead line a circuit breaker in a very high voltage substation.

 There are known such disconnectors comprising a plurality of conductive elements, which can fit into one another (open disconnector) and which can be deployed (closed disconnector) the elements are provided with contacts to ensure the electrical conduction of the telescopic assembly at least when the elements are deployed.

 The present invention relates more particularly to the mode of displacement of the various elements with respect to each other, this displacement allowing the passage from the open state of the disconnector where the elements are fitted one into the other, to the closed state of the disconnector where the elements are end to end.

 A type of disconnector is known in which the telescopic elements comprise one or more threaded rods which cooperate with the pinions. This solution is expensive to manufacture and operate due to the maintenance required.

 A disconnector is also known in which the movement of the telescopic elements is ensured pneumatically by means of a source of compressed air.

 This arrangement does not allow the closed or open state of the disconnector to be checked with certainty; it is also subject to operating faults, in particular the maintenance blocked in the closed position despite the opening order. In addition, in the event of a failure on the pneumatic network, the manual operation of the disconnector is difficult.

 An object of the present invention is to provide a telescopic disconnector of cost price and moderate maintenance cost and safe operation.

 The subject of the invention is a telescopic disconnector comprising a support structure surmounted by a hollow insulating column above and in the extension of which are placed a plurality of telescopic metal elements provided with contacts to ensure electrical continuity between them when the disconnector telescopic is in extension, the elements sliding two by two into one another and driving each other two by two, characterized in that the extension and the interlocking of the various telescopic elements is ensured by means of a rod insulating material fixed to one of the telescopic elements, said insulating rod being housed and sliding in the insulating column, the vertical displacement of this rod being ensured by means of at least one cable fixed at a point on the rod close to its lower end and following a closed path inside the column, between a drum provided with a rotation means and placed under the column, and a deflection raceway s located near the top of the column.

 According to a preferred embodiment, the telescopic element having the largest diameter is located at the upper part of the disconnector.

 In a particular embodiment, the cable is replaced over at least part of its length by a plurality of parallel wires of diameter smaller than that of the cable.

The invention will be better understood from the description given below with reference to various embodiments of the invention, with reference to the appended drawing in which
FIG. 1 represents a general view of the telescopic disconnector of the invention, in elevation, in the open position, - FIG. 2 is a side view of the same disconnector, in the closed position, - FIG. 3 is a perspective diagram of the mechanism drawing of the telescopic elements, according to a first embodiment, - Figure 4 is a detailed view of the drum for winding the drive cables, - Figures 5A and 5B are views in elevation and in profile, in section partial, of the device for fixing the drive cables to one of the telescopic elements, - Figure 6 is a view in axial section of the device for returning the drive cables, - Figure 7 is a view in section along the line VII-VII of Figure 6, - Figure 8 is an axial sectional view of the telescopic elements when the disconnector is in the open position, - Figures 9 and 10 show details of Figure 8, - Figure 11 is a partial view in axial section at é elevation of a telescopic disconnector according to another embodiment, - Figure 12 is a sectional profile view of the same disconnector, - Figure 13 is a sectional view along the line XIII-XIII of Figure 12, - the FIG. 14 is an enlarged view of the device for returning the drive cables, - FIG. 15 is a sectional view along the line XV-XV of FIG. 14.

 Figure 1 shows, in the open position, a telescopic switch according to the invention.

 It comprises a support structure 1 on the ground comprising several pillars such as 10 supporting a platform 11, located between 2 and 3 meters above the ground level.

 On the support structure is placed a hollow ceramic insulating column 12, held by insulating shrouds 13.

 The column is surmounted by telescopic elements 14A, 11IB, 14C, .... 14N, metallic, which, when deployed as in the case of Figure 2, allow the routing of current between an overhead line 15 and a return conductor 16 placed in the vicinity of the top of the column.

 The drive mechanism for the telescopic elements is shown diagrammatically in Figure 3.

 It includes a winding and unwinding drum 20 of a system of insulating cables 30 ensuring the driving of an insulating rod 50 whose role is to push up the telescopic element 14A which drives the other telescopic elements during of the disconnector closing operation, and on the contrary to drive it down during the disconnector opening operation.

 The drum can be rotated manually, for example by means of a crank, or, preferably, using a geared motor 21 as shown in FIG. 1.

 The insulating rod 50, preferably tubular for the sake of rigidity and lightening, is housed, when the disconnector is open, in the insulating column 12. In reality, as can be seen in FIG. 5, its lower part exceeds the bottom of the column 12 and crosses the platform 11 through an orifice 11A made in the latter at the right of the column. A tube 17 fixed under the platform in the extension of the column ensures the protection of the lower part of the rod 50.

 The drive cables of the rod 50, which will be described in detail below, take a path, most of which is inside the insulating column 12.

 In a first embodiment described with reference to FIGS. 3 to 7, the cable system comprises - a first cable 31, fixed by one end to a point 31A of the drum 20 and by a second end, to the lower part of the rod 50, preferably by screwing a piece 50D onto a flange 50C.

 The cable 31 passes over a mad pulley 61 which guides it towards the entry of the column 12. The cable is made of insulating material, preferably of extruded polyvinyl chloride reinforced by glass wires, with a diameter between 8 and 12 mm - a group of wires, preferably four in number, parallel, thinner and more flexible than cable 31.

 These wires, referenced 33A to 33D, have a first end fixed to the part 50D. They follow inside the column 12 a path parallel to the rod 50, pass around a deflection drum 34 disposed at the upper part of the column 12 and start again parallel to the rod being guided by a set of pulleys 35A to 35E or a raceway consisting of bicycle or motorcycle chains which bring them inside the column 12. Their second end is fixed to an insulating part 36.

- A cable 32, of the same diameter and in the same material as the cable 31 having a first end fixed to the part 36 and a second end fixed at a point 32A of the drum 20, opposite to point 31A.

 This cable 32 runs parallel to the rod 50, inside the column 12, but in reverse movement (or in opposite direction).

 It emerges at the lower end of the column where it passes over a mad pulley 62 before being wound up on the drum 20; the cable 32 is wound on the drum 20 opposite the cable 31 and in the same direction, so that a rotation of the drum winds one of the cables and unwinds the other and vice versa.

 In this way, whatever the direction of rotation of the drum, all cables and wires work in traction.

 The return drum is placed and fixed on a base 40 at the top of the insulating column 12 and protected by a cover 41.

 Figures 8 to 10 show the telescopic elements.

 Note that the larger diameter element is located at the top of the stack of elements (Figure 8) so as to give the assembly a better seal against rain.

 Each element other than the end elements 14A and 14N, for example the element 14B, is constituted by a metal tube 141B. At the upper part (fiv.10) of the tube is welded a cap 142B with an outside diameter greater than the outside diameter of the tube 141, but close to the inside diameter of the tube of the adjacent telescopic element 14A. This cap carries an annular zone 143B of electrical contact; the cap is pierced at its top for the passage of the drive rod 50. At the bottom the tube 141B (see FIG. 9) carries a crown 144B, welded pierced from place to place for the passage of elastic contacts with blades such 145B distributed at the periphery. The contacts are protected by a sleeve 148 having a lower part 147B whose internal diameter is close to the outside diameter of the cap of the inner adjacent element 14C, so as to allow the element to be driven. 14C when the sleeve of the element 14B reaches the cap of the element 14C.

 When the sleeve of an element reaches the cap of the inner adjacent element, the blade contact of the first comes to bear on the contact zone of the second, as shown in Figure 10, thus ensuring good electrical continuity between the two elements .

 The end elements are different: the element 14A, which has the largest diameter, does not have a contact zone 143. It directly receives the thrust from the tubular rod 50 to which it is fixed; its cap 142A is therefore closed and carries an electrical contact 146 cooperating with a corresponding contact carried by the line 15; the element 14N, which has the smallest diameter slides along a metal tube 51 which extends upwards from the top of the column. The metal tube partly serves as a guide for the tubular rod 50.

 This preferably has a lower part SOA, the diameter of which is close to that of the tube 51 and an upper part 50B of smaller diameter (see FIG. 6).

 The operation of the disconnector is as follows.

- In the open position, the configuration is that of FIG. 8 where the telescopic elements are all nested one inside the other - a rotation of the drum 20 in a direction producing the unwinding of the cable 31 causes an upward drive of the rod 50 which drives the telescopic element 14A, which drives the element 14B and so on until the switch is fully deployed. Then contact 146 reaches line 15 and the disconnector is electrically closed.

 A rotation in opposite direction of the drum 20 produces the descent of the tube and the successive repositioning of the various telescopic elements by drive.

 In the embodiment which has just been described, it has been chosen to use, for crossing the column 12, several fine wires instead of a single cable, so as to allow the use of a pulley 34 small diameter return.

 If you agree to have a large diameter return pulley, you can avoid the need for wires and use one or more cables, each in one piece.

 Figures 11 to 15 describe an alternative embodiment produced according to this principle.

 The same reference numerals have been used to designate the elements unchanged from the previous figures. In this version, the tube 50 is driven by means of two cables 81 and 91, arranged identically.

 Thus the cable 81 has a first end 81A fixed to a pulley 82 of the drum 20; it is guided towards the column by a pulley 83; it is fixed to the base 51 of the rod 12 at a point 84 by means of a screw 85 and a cleat 86; it passes over a return pulley 87 at the top of the column 12 and returns to the column being guided by a tube 88; at the outlet of the column, guided by a pulley 89, it is wound on the pulley 82 and its second end is fixed to it at a point 81B.

 The cable 91 runs parallel to the cable 81 and symmetrically with respect to the axis of the column 12.

 Fixed at a point 91A of the pulley 92 of the drum 20, it is guided towards the column by a pulley 93, is fixed to the rod 15 by screw 95 and cleat 96, passes over a return pulley 97, returns to the column by a tube 98, and, at the outlet of the column, guided by a pulley 99, is wound again on the pulley 92 where its second end 91B is fixed there.

 Cables 81 and 91 always work in traction; the operation is the same as that described above.

 The telescopic switch of the invention has perfectly safe operation. A manual operation can always be substituted for the engine-controlled operation. The positioning of the end contact can be precisely determined by measuring the unwound cable.

 The invention applies to the equipment of very high voltage substations.

Claims (3)

1 / Telescopic disconnector comprising a support structure surmounted by a hollow insulating column above and in the extension of which are placed a plurality of telescopic metal elements provided with contacts to ensure electrical continuity between them when the telescopic disconnector is extended, the elements sliding two by two one inside the other and driving each other, two by two, characterized in that the extension and nesting of the various telescopic elements (14A, 14B, ... 14N) is ensured at by means of an insulating rod (50) fixed to one of the telescopic elements, said insulating rod being housed and sliding in the insulating column (12), the vertical displacement of this rod being ensured by means of at least one cable ( 31) fixed at a point on the rod close to its lower end and following a closed path inside the column, between a drum (20) provided with a rotation means and placed under the column, and a device for r shipment located near the top of the column. 2 / Telescopic disconnector according to claim 1, characterized in that the telescopic element (14A) having the largest diameter is located at the upper part of the disconnector. 3 / Telescopic disconnector according to one of claims 1 and 2, characterized in that the cable (31) is replaced over at least part of its length by a plurality of parallel wires (33A, B, C, D) of smaller diameter than that of the cable.