JP2662700B2 - Power cable connection - Google Patents

Description

The present invention relates to a connection portion of a single-core power cable such as a single-core oil-paper insulated aluminum power cable.

(Prior Art) FIG. 2 is a longitudinal sectional view of a part of a conventional single-core power cable connection part.

In the drawings, (CA) and (CB) are power cables to be connected, (1A) and (1B) are cable conductors, (2A) and (2B) are cable cores with an oil-paper insulation layer, and (3A) and (3B) are It is a metal sheath such as an aluminum sheath. The cable conductors (1A) and (1B) are compression-connected by a sleeve (4), and are formed by, for example, winding a wide insulating paper over the sleeve compression connection portion and the left and right cable cores (2A) and (2B). The reinforcing insulating layer (7) is provided, and stress cones (9A) and (9B) are applied to the inclined portions on both sides of the reinforcing insulating layer (7).

External case (11A) (1
1B) is arranged, one end of each is joined to the flange part, the other end is located on the metal sheath (3A) (3B) of the cable (CA) (CB), respectively, lead work (12A) (12B)
Are connected to the metal sheaths (3A) and (3B).

(Problems to be Solved) In the above-mentioned conventional power cable connection portion, the outer diameter of the conductor connection sleeve (4) is usually equal to the cable core (2A).
(2B) In the case of an oil-paper insulated cable, which is smaller, the insulating layer has a multi-layer structure formed by winding an insulating paper tape having a thickness of 0.1 to 0.2 mm to a predetermined thickness, and the reinforcing insulating layer (7) and stress The cone (9A) (9B) is not fixed to the outer case (11A) (11B).

Therefore, if the thermal stress caused by the temperature change occurring in the conductors (1A) (1B) at both ends of the connection part or the sliding force in the case of laying an unbalanced ground is unbalanced, the shear force acts, and the metal sheath of the cable ( The force acts on the stress cone provided with its end in contact with 3A) and (3B), and the stress cone (9A)
(9B) The cable insulation layer or the reinforcement insulation layer (7) is damaged due to the displacement of the conductor due to the damage of the cable insulation layer at or near it or the multilayer structure of the cable insulation layer. May cause dielectric breakdown.

(Means for Solving the Problems) The present invention provides a connection portion for a power cable that solves the above-mentioned problems, and is characterized by comprising a multi-layer oil-impregnated paper insulation layer, and a metal sheath on the outside thereof. A synthetic resin insulator whose outer diameter is larger than a cable core diameter is provided on an outer peripheral portion of a sleeve for compressively connecting the left and right cable conductors, and both side surfaces of the synthetic resin insulator. Are provided with reinforcing insulators, one end of which is in contact with the other and the other end is extended to the stress cone.A reinforcing insulating layer is provided on the outer and inner sides of the reinforcing insulator by a roll of insulating paper. A fixing bracket having one end fixed to the outer case is provided, and the end of the outer case is lead-connected to a metal sheath.

FIG. 1 is a longitudinal sectional view of a main part of a specific example of a power cable connecting portion of the present invention. The same symbols as those in FIG. 2 represent the same parts.

Left and right cable conductors (1A) (1B) as shown in the drawing
An insulator (5) made of a synthetic resin such as an epoxy resin is provided on an outer peripheral portion of the sleeve (4) for compressively connecting the sleeve (4).
The outer diameter (DE) is formed larger than the outer diameter (DC) of the cable cores (2A) (2B). Left and right cables, one end of which abuts on both sides of the synthetic resin insulator (5), and the other end extends to stress cones (9A) (9B) provided on both sides of the reinforcing insulating layer (7). Reinforcement insulators (6A) (6B) having the strength to withstand the imbalance of the axial force acting on the conductors (1A) (1B) are provided.

Outside the reinforcing insulators (6A) and (6B) and the synthetic resin insulator (5), a normal reinforcing insulating layer (7) and a shielding layer (8) are provided to form a reinforcing insulator (6A) (6B). A similar reinforcing insulating layer (7) is also provided on the inner layer side to reduce electric stress applied to the synthetic resin insulator (5) and the reinforcing insulators (6A) (6B).

Stress cone (9A) on both sides of reinforced insulation layer (7)
(9B) is provided, and on the outer surface of the stress cone (9A) (9B), a metal fitting (10A) (10B) having one end fixed to the outer case (11A) (11B) is abutted, and is made of synthetic resin. The reinforcing insulators (6A) and (6B) are sandwiched between the insulator (5).

Outside case (11A) (11B) outside the above connection
Place. One end of the outer case (10A) (10B) is joined to each other at its flange, and the other end is located on the metal sheath (3A) (3B), respectively, and the lead sheath (12A) (12B) uses the metal sheath (3A). Connect to (3B).

(Operation) In the power cable connecting portion configured as described above, the cable conductors (1A) and (1B) are compression-connected by the sleeve (4), and the sleeve (4) has an outer diameter larger than the cable core diameter. A synthetic resin insulator (5) is provided, and fixing metal fittings (10A) (10) abutting on the outer surfaces of the synthetic resin insulator (5) and the stress cones (9A) (9B).
B) sandwiches the reinforcing insulators (6A) and (6B). Moreover, one end of each of the fixing brackets (10A) (10B) is fixed to the outer case (11A) (11B).

Therefore, as described above, the cable conductors (1A) and (1B) form the sleeve (4), the synthetic resin insulator (5), the reinforcing insulators (6A) (6B), and the fixtures (10A) (10B). It is mechanically integrally connected to the outer cases (11A) and (11B) through the intermediary.

With this configuration, the left and right cable conductors (1A)
The axial displacement force generated in (1B) is the outer case (11A) (1
1B), it is possible to prevent the occurrence of relative displacement between the conductor and the reinforcing insulating layer or between the reinforcing insulating layer and the outer case.

(Effect of the Invention) As described above, according to the connection portion of the power cable of the present invention, even if the axial force generated in the left and right cable conductors is unbalanced, the conductor and the reinforcing insulating layer or the reinforcing insulating layer Since there is no relative displacement between the cable and the outer case, the cable insulating layer and the reinforcing insulating layer are not damaged, and the dielectric breakdown accompanying the damage can be prevented, and the reliability is remarkably improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a specific example of a power cable connecting portion of the present invention. FIG. 2 is a longitudinal sectional view of a main part of an example of a conventional power cable connecting portion. CA, CB: Power cable, 1A, 1B: Cable conductor, 2
A, 2B …… Cable core, 3A, 3B …… Metal sheath, 4…
... Sleeve, 5 ... Synthetic resin insulator, 6A, 6B ... Reinforced insulator, 7 ... Reinforced insulating layer, 8 ... Shielding layer, 9A, 9B ...
Stress cone, 10A, 10B ... Fixing bracket, 11A, 11B ...
External case, 12A, 12B …… Leading part.

Claims (1)

(57) [Claims] 1. A power cable connection comprising a multi-layer oil-impregnated paper insulation layer and having a metal sheath on the outside thereof.
A synthetic resin insulator whose outer diameter is larger than the cable core diameter is provided on the outer peripheral portion of the sleeve for compressively connecting the left and right cable conductors, one end of each of which is in contact with both sides of the synthetic resin insulator, and the other end is a stress cone. A reinforcing insulator is provided on the outer and inner sides of the reinforcing insulator, a reinforcing insulating layer is provided on the outer surface of the stress cone, and a fixing bracket having one end fixed to an outer case is provided on the outer surface of the stress cone. And an end portion of the outer case is lead-connected to a metal sheath.