JPH03145915A - Power cable connection - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to power cable connections, and in particular to capacitor cone type terminal connections and intermediate connections of ultra-high voltage cables.

(Prior Art) FIG. 3 is a vertical cross-sectional view of a main part of a conventional capacitor type connection part, particularly a terminal connection part of a power cable called an inverted type.

In the drawings, (1) is a power cable, (11) is a cable sheath, (12) is a cable core, and (13) is a cable conductor. After forming a connection reinforcing insulating layer (2) by wrapping insulating paper on the cable core (12), a prefabricated condenser cone (3), which is made by arranging coaxial cylindrical metal foil and integrally molding it, is formed at the factory. The ground side (on the right side of the figure) is installed on the outer periphery of the reinforcing insulating layer (2) and is formed by the reinforcing insulating layer (2) and the capacitor cone (3).
The tapered portion formed a stress cone (4).

The above-mentioned capacitor cone (3) is of the so-called inverted type in which the electrode arrangement is such that the high-voltage side foil on the left side of the figure has a small diameter and the earth side foil on the right side has a large diameter.

(Problem to be solved) In the conventional power cable connection section mentioned above, reinforced insulation! !
Prefabricated condenser cone (3) on the outer periphery of (2)
Since the insulating layer is formed by inserting an insulating layer, it is necessary to allow a certain amount of gap to exist between the two interfaces due to the pushing operation. Therefore, the stress at point A, which is the vertical lily point of the condenser cone (3), is calculated using the equation (1).

Here Enia [! Pressure tR: Composite permittivity of reinforcing insulation layer and cable insulation layer tO2 Dielectric constant of gap dO: Inner diameter of capacitor cone dc: Outer diameter of cable conductor (3) It is necessary to determine the inner diameter (do), and the outer diameter (Do), which is determined by the required number of electrodes based on this inner diameter (do), also inevitably becomes large.

(Means for Solving the Problems) The present invention solves the above-mentioned problems and provides a power cable connection part that can reduce the outer diameter. The reinforcing insulating layer forming the stress cone is formed such that at least a portion thereof overlaps in the longitudinal direction.

FIG. 1 is a longitudinal cross-sectional view of a main part of an example of a power cable connection unit according to the present invention. Note that the same symbols as in FIG. 3 represent the same parts.

In this specific example, the capacitor cone (
Condenser cone (3) except for the upper taper in 3)
A reinforcing insulating layer (5) that is connected to the tapered portion of the reinforcing insulating layer (2) to form a stress cone is formed so as to overlap in the longitudinal direction. Then, from the top of the capacitor cone (3), a newly formed reinforcing insulating layer (5)
A stress cone (4) is formed over the tapered portion of the

FIG. 2 is a longitudinal cross-sectional view of a main part of another specific example of the power cable connection portion of the present invention. In this specific example, the reinforcing insulating layer (5), which forms a stress cone by being connected to the entire tapered part formed by the capacitor cone (3) on the ground side and the reinforcing insulating ff (2), is extended by L2 in the longitudinal direction. Form so that they overlap. A stress cone (4) is then formed on the tapered portion of the newly formed reinforcing insulating layer (5).

(Function) In the power cable connection part of the present invention described above, A1
The stress (T') at a point is given by the following equation.

a, if τ in equation (1) and r' in equation (2) are τ = 1, then do >do', and the condenser cone (3
) can be reduced in inner diameter (do') and outer diameter (Do').

(Example) An example of a trial calculation for a 550kV, OF cable terminal connection section is shown below.

In the conventional connection shown in Fig. 3, the allowable stress at point A is From the response hmm Denser cone (3) Inner diameter (do) = The distance was set at 140m.

at this time vinegar to Re S τ is becomes.

The outer diameter (Ds) of the reinforcing insulating layer (5) to achieve the same stress at point A as in the conventional case is DS: 180 mmφ.

Table 1 shows a comparison of the outer diameters of the connecting portions of both.

Table 1 (Effects of the Invention) As explained above, according to the power cable connection part of the present invention, it is possible to reduce the inner and outer diameters of the condenser cone, making it possible to make the connection part more compact and economical. .

Therefore, it is extremely effective especially when used for forming terminal connections and intermediate connections of ultra-high voltage electrical cables.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are both longitudinal cross-sectional views of essential parts of a specific example of the connection portion of a power cable according to the present invention. FIG. 3 is a longitudinal cross-sectional view of the main parts of a conventional power cable connection section. DESCRIPTION OF SYMBOLS 1...Power cable, 2...Connection part reinforcing insulating layer, 3
...Prefabricated condenser cone, 4... Stress cone, 5... Stress cone forming reinforcing insulating layer.

Claims (1)

[Claims] (1) A prefabricated condenser cone with coaxial cylindrical metal foil arranged on the outer periphery of the connection reinforcing insulation layer. Among the condenser cone type power cable connections, the high-voltage side foil has a small diameter, and the ground side foil has a diameter In an inverted type connection part having a large electrode arrangement, the reinforcing insulating layer that connects to the ground side capacitor cone to form a stress cone is formed so that at least a part of it overlaps the capacitor cone in the longitudinal direction. Features power cable connections.