ELECTRICAL CABLE CONNECTION AND CORRESPONDING INSTALLATION PROCEDURE

Description

[0001] The present invention relates to an electrical cable junction and a method for installing such a junction. The invention also relates to an electrical cable equipped with such a junction.

[0002] The invention relates to the field of electrical cable joints. It is particularly applicable to joints in power cables, for example, medium and high voltage (between approximately 1 kV and approximately 72 kV), comprising one or more types of sealants, resins, or gels, which exhibit electrical properties and are arranged in one or more layers. These fluid substances with electrical properties have, for example, a dielectric strength greater than 10 kV / mm.

[0003] The aforementioned sealants, resins, or gels are substances that can flow, particularly under certain temperature and pressure conditions, or when subjected to mechanical stress. It is undesirable for a sealant, resin, or gel with electrical properties used in a cable joint to overflow from the defined area(s) where it has been applied. Therefore, a retaining element is generally provided for the sealant, resin, or gel.

[0004] Thus, document EP-A-2 839 543 describes an electrical cable connection assembly in which a fluid sealant, such as a mastic, surrounds part of the electrically conductive connector body that joins the two cables. A ring-shaped barrier to prevent the sealant from flowing out is provided on the connector body.

[0005] However, this type of arrangement has several drawbacks. In particular, it does not guarantee the containment of the sealant, since the sealant is applied to the outer surface of the connector. It also does not guarantee that cables connected by such a connector can be stored at high temperatures or pressures, again due to the risk of sealant leakage or deformation. Furthermore, the various components of the connector are susceptible to slippage relative to one another due to the fluidity of the sealant. Moreover, for the same reason, installing such a connector is not easy.

[0006] US document 9 178 289 B2 discloses joint bodies and methods for covering electrical connections and cables.

[0007] Document EP 2 284 972 A1 discloses an assembly for installing a cold shrink elastic sleeve for electrical cables.

[0008] The present invention aims to remedy the aforementioned drawbacks of the prior art.

[0009] To this end, the present invention proposes a power electrical cable junction according to claim 1.

[0010] Thus, once the joint is in place, after removal of the removable tube and film, the fluid remains confined under the sleeve. This provides electrical insulation ensuring user safety, prevents sleeve slippage, makes cables equipped with such a joint resistant to storage at high temperature or pressure (for example, at least one week at 65°C), and reduces friction during joint installation.

[0011] Furthermore, this cable junction also has the advantage of being able to be pre-assembled in the factory, which further facilitates its subsequent installation on site and avoids having to handle a substance with electrical properties on the installation site.

[0012] In one particular embodiment, the film is made of polyester. This material has the advantage of being able to withstand tensile forces without stretching. This allows for satisfactory extraction of the film when installing the splice on cables, as described in detail later.

[0013] In one particular embodiment, the film is coated with silicone on both sides. The silicone layer in contact with the removable tube is advantageous due to its sliding properties, as these facilitate the film's removal when installing the connector on cables. The silicone layer on the side facing the fluid is advantageous due to its anti-adhesion properties, as this prevents the fluid from adhering to the removable film.

[0014] In a particular embodiment, the surface of the tube has a predetermined granulometry allowing any element placed on the tube to be set in motion even if that element exerts a significant load, up to 5 daN / cm².

[0015] In one particular embodiment, the tube is made of polycarbonate. This further increases the joint's resistance to storage at high temperatures or pressures. For example, the tube can thus withstand pressure forces exceeding 1 daN / cm² exerted by the shrink sleeve under storage conditions ranging from -20°C to +80°C.

[0016] In one particular embodiment, the tube is cylindrical. This shape is advantageous for achieving good mechanical stability of the joint.

[0017] In one particular embodiment, the shrink sleeve is made of EPDM (Ethylene Propylene Diene Monomer). This material is advantageous because it provides the shrink sleeve with elongation properties and the ability to return to its original shape after the film and tube are removed during cable splicing. Furthermore, this material offers advantageous electrical characteristics, such as high electrical insulation and control of electric fields.

[0018] In one particular embodiment, the shrink sleeve is made of silicone. This material is advantageous because it offers excellent resistance to high temperatures.

[0019] For the same purpose as indicated above, the present invention also proposes an electrical power cable comprising at least two cable segments, notable in that at least two of the at least two cable segments are connected to each other by a power cable junction such as is succinctly described above.

[0020] For example, but not necessarily, it could be a medium voltage or high voltage cable.

[0021] For the same purpose as indicated above, the present invention also proposes a power electrical cable connection assembly comprising two power electrical cable segments and a mechanical connector assembling the two cable segments, said assembly being remarkable in that it further comprises a power electrical cable junction as briefly described above arranged around the mechanical connector and at least a part of the two cable segments.

[0022] Since the special characteristics and advantages of the cable and connection assembly are similar to those of the junction, they are not repeated here.

[0023] With the same aim as indicated above, the present invention further proposes a method for installing a power electrical cable junction as briefly described above, between two power electrical cable segments mechanically assembled by a mechanical connector, the method being remarkable in that it includes a step consisting of removing, by pulling with the aid of a hook, the aforementioned removable tube and film.

[0024] The installation of the junction is thus greatly facilitated: it can be carried out in a single operation, due to the fact that the various electrical elements are brought together in a single overall electrical part on the removable tube, thanks to the structure of the junction briefly described above. Brief description of the drawings

[0025] Other aspects and advantages of the invention will become apparent from the following detailed description of particular embodiments, given by way of non-limiting examples, with reference to the accompanying drawings, in which: [ Fig. 1 [ ] is a schematic view of a power cable junction according to the present invention, in a particular embodiment and in a state prior to installation. Fig. 2[ ] is a schematic view of a mechanical connector joining two cable segments of a power electrical cable according to the present invention, in a particular embodiment. Fig. 3 [ ] is a schematic view illustrating the method of installing the junction according to the present invention, in a particular embodiment. Fig. 4 ] is a schematic view partially showing the inside of the junction once the installation is complete, in a particular embodiment. Description of method(s) of implementation

[0026] As shown by figure 1Before installation on cables or cable segments, a power electrical cable junction 10 according to the present invention includes a support tube 12. The support tube 12 is removable, as described in more detail below, because it serves only as a support for the making of the junction 10. After installation on cables or cable segments, the junction 10 no longer includes the support tube 12.

[0027] In the particular embodiment illustrated, the tube 12 is cylindrical in shape. However, it could have any other shape deemed appropriate, such as a flattened shape or a rectangular or square cross-section; these examples are given by way of non-limiting.

[0028] Advantageously, but not necessarily, tube 12 can be made from polycarbonate. It may contain polycarbonate and other components, or be made entirely of polycarbonate.

[0029] Before installation, the junction 10 also includes a film 14 placed on the tube 12. The film 14 is also removable, as described in more detail below. After installation, the junction 10 no longer includes the film 14.

[0030] Before installation, the film 14 is placed on all or part of the outer surface of the tube 12.

[0031] Advantageously, but not necessarily, film 14 can be made from polyester. It may contain polyester and other constituents, or be made entirely of polyester.

[0032] According to the invention, the film 14 is coated, on one of its faces or, preferably, on both of its faces, with a layer of predetermined thickness, for example a few microns, of a material comprising silicone and other constituents, or comprising only silicone.

[0033] Advantageously, but not necessarily, the surface of the tube 12, either on one face or on both faces, has a specific grain size. The roughness of the tube 12 is such that the film 14, although subjected to a significant load, can be easily removed during the installation of the junction 10 on cables. By way of non-limiting example, the roughness of the tube's outer surface can range from minimum values ​​of Ra = 3.2 µm and Rz = 12.5 µm to maximum values ​​of Ra = 6.3 µm and Rz = 25 µm.

[0034] Thus, thanks to the invention, any element present on the tube 12 can be set in motion even if that element exerts a load of up to 5 daN / cm 2.

[0035] The junction 10 further includes a sleeve 16 which, before installation of the cable junction, is positioned around the removable tube 12 and the removable film 14. The sleeve 16 is shrinkable, for example heat-shrinkable or pressure-shrinkable, and is initially in an expanded state. It will be in a retracted state once the installation is complete.

[0036] Advantageously, but not necessarily, sleeve 16 can be made from EPDM (Ethylene-Propylene-Diene Monomer). It may contain EPDM and other constituents, or be entirely made of EPDM.

[0037] Alternatively, sleeve 16 can be made from silicone. It may contain silicone and other components, or be made entirely of silicone.

[0038] According to the present invention, the junction 10 further comprises a fluid substance 18 having electrical properties and at least two retaining rings 20 for the fluid substance 18, coaxial to the sleeve 16 and arranged under the sleeve 16. The fluid substance 18 is also arranged under the sleeve 16, between the two rings 20, or between two successive rings 20 if the junction 10 comprises more than two rings 20.

[0039] By way of non-limiting example, fluid substance 18 may comprise one or more types of sealant, resin or gel or any other fluid material having suitable electrical properties.

[0040] Regardless of the total number of rings, two successive rings 20 are arranged at a predetermined non-zero distance from each other, this distance being a function of the quantity of fluid substance 18 expected between the two rings considered and the desired thickness for the layer of fluid substance 18. More generally, the rings 20 are dimensioned so as to confine the fluid substance 18.

[0041] Like the sleeve 16, the rings 20 can be made from EPDM or silicone. The material can be changed depending on the application and the stresses to be borne.

[0042] Junction 10 can be installed between two power cables to connect them electrically. Similarly, it can be installed between two cable segments of the same power cable.

[0043] Advantageously, this cable or these cables are medium voltage or high voltage. These examples of cables are not limiting. The invention can be applied to other types of cables.

[0044] The invention allows the junction 10 to conform to the shape of the connection between the cables or cable segments considered. Thanks to the elastic properties of the junction 10, cables of different cross-sections can be connected.

[0045] Thus, as the figure 2 In a particular embodiment, a power cable according to the present invention comprises at least two cable segments 21 and 23. These two segments 21, 23 (or two successive cable segments if the cable comprises more than two segments) are mechanically joined by a mechanical connector 22.

[0046] One could just as well consider that the mechanical connector 22 mechanically connects together, not two segments of the same cable, but two electrical cables.

[0047] As shown by the particular method of implementation of the figure 4 , once the junction 10 is installed and thus electrically connects the cable segments 21 and 23, a power electrical cable connection assembly 40 is formed, which includes the two segments 21, 23, the mechanical connector 22 and the junction 10.

[0048] The junction 10 is arranged around the mechanical connector 22 and at least a part of the two segments 21, 23, this part containing at least the ends of the segments assembled by the mechanical connector 22.

[0049] The installation procedure for junction 10 is illustrated by the figure 3 in a particular embodiment.

[0050] This maneuver consists, for an operator, of removing with one hand, by pulling towards him with the help of a hook 30, by one side of the junction 10, the tube 12 and the film 14 which, as described above, are removable for this purpose.

[0051] During this maneuver, the operator can hold with their other hand a portion of the cable, or cable segment, located on the other side of junction 10, as illustrated in the region of the figure 3 surrounded by dashes.

[0052] The result of this maneuver is illustrated on the figure 3 under the vertical arrow: the electrical connection via junction 10 is then made.

Claims

1. An electrical power cable joint (10), comprising: a removable tube (12); a removable film (14) provided on said removable tube (12); a retractable sleeve (16) provided around said removable tube (12) and said removable film (14); said joint (10) further comprising a fluid substance (18) having electrical properties provided beneath said retractable sleeve (16), and at least two rings (20) that are coaxial with said retractable sleeve (16) and arranged at a predetermined non-zero distance from one another beneath said retractable sleeve (16), said fluid substance (18) being provided between said at least two rings (20), said at least two rings (20) being provided beneath said retractable sleeve (16) and being sized so as to contain said fluid substance (18) and in which said film (14) is coated with a silicone-containing material at least on the side of said fluid substance (18).

2. The joint (10) according to claim 1, characterized in that said film (14) is made of polyester.

3. The joint (10) according to claim 1 or 2, characterized in that said film (14) is coated with silicone on the two faces thereof.

4. The joint (10) according to claim 1, 2, or 3, characterized in that the surface of said tube (12) has a predetermined grain size.

5. The joint (10) according to any one of the preceding claims, characterized in that said tube (12) is made of polycarbonate.

6. The joint (10) according to any one of the preceding claims, characterized in that said tube (12) is cylindrical.

7. The joint (10) according to any one of the preceding claims, characterized in that said retractable sleeve (16) is made of EPDM.

8. The joint (10) according to any one of claims 1 to 6, characterized in that said retractable sleeve (16) is made of silicone.

9. An electrical power cable comprising at least two cable segments (21, 23), characterized in that at least two of said at least two cable segments (21, 23) are interconnected by a power cable joint (10) according to any one of the preceding claims.

10. The cable according to the preceding claim, characterized in that it is a medium-voltage or high-voltage cable.

11. An electrical power cable connection assembly (40) comprising two electrical power cable segments (21, 23) and a mechanical connector (22) that joins said two cable segments (21, 23), said assembly being characterized in that it further comprises an electrical power cable joint (10) according to any one of claims 1 to 8, provided around said mechanical connector (22) and at least a portion of said two cable segments (21, 23).

12. A method for installing an electrical power cable joint (10) according to any one of claims 1 to 8, between two electrical power cable segments (21, 23) that are mechanically joined by a mechanical connector (22), said method being characterized in that it comprises a step of removing, by pulling with a hook (30), said removable tube (12) and said removable film (14).