JPS5819115A - Method of bonding sheath of conduit gas cable - 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 The present invention relates to a solid bonding method in a single-core aerial cable line.

In a single-core aerial cable line, the three phases are solid-bonded near the end of each cable on the same side, and a sheath current of the same magnitude and phase lead as the conductor current is applied to the metal sheath of the cable. In general, the leakage magnetic field to the outside of the cable was cancelled.

In this case, due to the arrangement and spacing of the cable lines, there is a possibility that reinforcing bars and other iron structures existing in the vicinity of the cable line may generate heat, or if some necessary measures are to be taken on the cable lines. The entire length of the line had to be considered, creating industrial problems and uneconomical consequences.

This invention provides a sheath bonding method for single-core aerial cables that can eliminate the problems and uneconomical problems associated with construction.
Its purpose is to provide.

The gist of the present invention lies in the configuration of a sheath bonding method for a single-core, conduit aerial cable line as described in the above claims.

Hereinafter, the present invention will be explained in detail with reference to the drawings showing one embodiment thereof. FIG. 1 is a system diagram of a single-core aerial cable line for explaining the present invention. In the figure, C1,
C, , C8 are single-core pipe aerial cable installation lines,
1.1' is the cable CI, 1.2.2' is the cable C2, and 8.8' is the cable C3. 4, 4' are the cables c, ,
C2, C, respective both end terminations 1.2.3 and ll
, 2', by the method conventionally employed for three-phase solid bonds in the vicinity of al. 5.5' is a solid bond according to the present invention and connects the cables CI + CB arranged symmetrically to the cable C2, which is laid in a geometrically central position, to each of the cables CI +
Sheath bonds are symmetrically applied to the cable Cg near both ends of the symmetrical installation portion of 021 CB. And the cable itself.

Since the symmetrical installation sections of C2 and CB are balanced in terms of the cable line arrangement, the sheath bonds 5 and 5' are applied to the outermost ends on both sides of the sections that are electromagnetically balanced in terms of the cable line arrangement. There is.

Since this invention has the above configuration, the cable CI
+C2+ The section between sheath bond 5.5' of CB is electromagnetically balanced due to the line arrangement of the cables cl, C2, and C8, so the influence on the reinforcing bars near this section and the base steel structure is extremely small. , and the line arrangement is also electromagnetically balanced, making it easy to handle various electrical calculations.Especially in tunnels, the line arrangement is electromagnetically balanced, so the section between the sheath bonds 5 and 5' The civil engineering design of the tunnel will be easier if the tracks are placed so that the tunnel section is located at

In addition, since the length of the sheathed bond wires 5, 5' is usually short and therefore the impedance is small, the bond wires 5.5'
The cable c1° C2, C in the section sandwiched between
The resistance to the sheath current of each of the cables CI, C2, and CB is small, and the sheath current has the same magnitude and opposite phase as the conductor current, so that the magnetic field from each of the cables c1 + C2+ c is external to the cables CI, C2, and CB. There will be no leakage. On the other hand, the conventional bond wires 4, 4' are long in length and therefore have a large impedance, and therefore have a large resistance to current.If the bonds 5, 5' are not provided, the cables CI, C2, CB The sheath current of the cable C, , is smaller than the conductor current.
The electromagnetic blocking effect due to the sheath current of C2, Ca is insufficient, and the magnetic field due to the conductor current is applied to the cables CI, C2.
, leaks to the outside of C8.

In this case, by applying the bond 5.5' according to the present invention, measures can be taken only in the sections of the bond 4.5 and i, l, and 51 in the cable line, and the measures can be taken over the entire length of the cable line. Countermeasures can be taken more easily and quickly than in the case of taking countermeasures.

Since this invention has the above-mentioned structure and operation, according to the invention, the section where the line arrangement of the single-core aerial cable is electromagnetically balanced and the section other than that are separately covered by the cable sheath. Countermeasures against electromagnetic interference can be taken. In other words, even if the electromagnetically balanced section is long, countermeasures can be easily taken through calculations, and the electromagnetically unbalanced section is limited, so measures should be focused only on that section. This allows the civil engineering design (frames, hardware, reinforcing bars, etc.) for the installation of single-core aerial cable lines to be carried out easily, reliably, and quickly. It can be installed so as not to have any electromagnetic influence on reinforcing bars and other iron structures near the railway line, which has a remarkable industrial effect.

Further, the present invention is not limited to application to a solid bond of a single-core pipe line aerial cable metal sheath, but is also applicable to a cable that cancels the external leakage magnetic field of the electromagnetic field generated by the conductor current by passing a current through the cable sheath. It can also be effectively applied to electrical equipment and has a wide range of applications.

[Brief explanation of the drawing]

The missing figure is a layout diagram of a single-core aerial cable line for explaining the present invention. C1+ cg + "8......Single-core pipe air cable, 1.1'2.2'8.8'...
...Single-core air cable termination part, 4.4'...Conventional cable sheath solid pond in single-core air cable, 5.5'...According to this invention Cable sheath solid pond for single-core air cable. “Bou/Diagram

Claims (3)

[Claims] (1) In a method of solid bonding the metal sheaths of each single-core conduit aerial cable constituting the line in a single-core conduit aerial cable line and passing a current through each metal sheath, the bond The inner bond is applied twice on the inside and outside, and the inner bond is applied between the outermost ends of the section where the line arrangement is at least electromagnetically balanced, as in the case where the three phases are laid with constant spacing, and the outer bond A sheath bonding method for a conduit aerial cable, characterized in that the bond is applied to the outside of the inner bond. (2) The method for sheath bonding a conduit aerial cable according to claim (1), wherein the electromagnetically balanced section is a tunnel section. (3) The method of sheath bonding an aerial cable for a conduit according to claim (1), wherein the electromagnetically balanced section is a section where countermeasures against leakage magnetic fields are required.