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EP-4213325-B1 - METHOD FOR MANUFACTURING AN ELECTRICAL CABLE JUNCTION, ASSOCIATED JUNCTION AND CABLE

EP4213325B1EP 4213325 B1EP4213325 B1EP 4213325B1EP-4213325-B1

Inventors

  • Carpentier, Ludovic
  • DEBIEVRE, Pascal
  • DURMOIS, Lionel
  • RIVALLAND, Yann
  • DE BUYST, JO

Dates

Publication Date
20260513
Application Date
20221214

Claims (8)

  1. Method for manufacturing a junction between two power cables, the method comprising assembly steps without moulding, consisting of: expand (10) an electrode (20) onto two removable support tubes (22); apply (12) at least one layer of fluid substance (24) having electrical properties onto said electrode (20); place (14) a retractable sleeve (26) around said electrode (20) and around said at least one layer of fluid substance (24).
  2. Method according to claim 1, characterised in that said electrode (20) is cold-retractable.
  3. Method according to claim 1 or 2, characterised in that said two tubes (22) are made of polycarbonate.
  4. Method according to claim 1, 2 or 3, characterised in that said two tubes (22) are cylindrical.
  5. Method according to any one of the preceding claims, characterised in that said retractable sleeve (26) is made of EPDM.
  6. Method according to any one of claims 1 to 4, characterised in that said retractable sleeve (26) is made of silicone.
  7. Power cable junction, consisting of an assembly without moulding comprising an electrode (20), at least one layer of fluid substance (24) having electrical properties, and a retractable sleeve (26), the said assembly without moulding being carried out by a method according to any one of the preceding claims.
  8. Power cable comprising at least two cable segments, characterised in that at least two of said cable segments are connected to one another by a power cable junction according to claim 7.

Description

The present invention relates to a method for manufacturing a power electrical cable junction, as well as to an associated power electrical cable junction and power electrical cable. 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. Modern junctions with integrated electrodes are generally manufactured by molding. The various components of the junction are thus fused together, and the junction structure is fixed. Consequently, it is only suitable for a specific voltage and a specific range of cross-sectional values for the target cables. Therefore, it is necessary to manufacture multiple junctions depending on the intended application. Furthermore, during installation of the junction on cables or subsequent handling of these cables, cracks or tears can occur between the different layers of the junction due to its one-piece construction. The document WO 02/078145 A1 discloses an industrial production method for cold shrink joints and multi-elastic wall terminations. The document WO 2020/208440 A1 discloses a support core for elastic sleeve. The document FR 2 790 863 A1 discloses a retractable sleeve support for electrical cable junction. The document EP 0 435 569 A1 discloses a radially shrinkable sleeve to contain a connection or terminal of an electrical cable. The document EP 3 764 492 A1 discloses a method for manufacturing a junction between the screens of two electrical cables and a corresponding junction. The document WO 97/32381 A1 discloses a cable closure assembly comprising a fluid material and a reinforcing core. The present invention aims to remedy the aforementioned drawbacks of the prior art. To this end, the present invention proposes a method for manufacturing a junction between two power electrical cables, remarkable in that it comprises mold-free assembly steps consisting of: expand an electrode on two removable support tubes; apply at least one layer of fluid substance exhibiting electrical properties to this electrode; place a shrink sleeve around the electrode and at least one layer of fluid substance. Thus, because the various components of the joint expand independently of each other and are assembled individually without molding, it becomes possible to adapt the lengths of these components to the constraints of the cables receiving the joint and to modify the type of fluid depending on the application (e.g., low, medium, or high voltage). This results in a versatile joint that can be produced in a wide range of configurations. Furthermore, this mold-free assembly helps to avoid cracks or tears between the different layers of the joint. Furthermore, thanks to the fluid substance already present in the joint, there is no need to grease the cables before installing the joint. In a particular embodiment, the electrode is cold-shrinkable. In one particular embodiment, both tubes are made of polycarbonate. This increases the joint's resistance to stress. storage at high temperature or pressure. For example, the tubes can thus withstand pressure forces of more than 1 daN/ cm2 exerted by the shrink sleeve under storage conditions between -20°C and +80°C. In a particular embodiment, the two tubes are cylindrical. This shape is advantageous for achieving good mechanical stability of the joint. 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 removal of the removable support tubes during cable connection. Furthermore, this material offers advantageous electrical characteristics, such as high electrical insulation and control of electric fields. Alternatively, the shrink sleeve can be made of silicone. This material is advantageous because it offers excellent resistance to high temperatures. For the same purpose as indicated above, the present invention also proposes a power electrical cable junction, remarkable in that it consists of a mold-free assembly comprising an electrode, at least one layer of fluid substance having electrical properties and a shrink sleeve, this mold-free assembly being made by a process as briefly described above. For the same purpose as indicated above, the present invention further 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 briefly described above. Since the specific characteristics and advantages of the joint