CN2318694Y

CN2318694Y - Concentric protection conductor low-voltage power cable

Info

Publication number: CN2318694Y
Application number: CN 97243370
Authority: CN
Inventors: 唐崇健
Original assignee: SHANGHAI MORN ELECTRIC CO Ltd
Current assignee: SHANGHAI MORN ELECTRIC CO Ltd
Priority date: 1997-12-29
Filing date: 1997-12-29
Publication date: 1999-05-12
Anticipated expiration: 2007-12-29

Abstract

The utility model relates to a low-voltage power cable with concentric protective conductors, comprising main wire cores, a neutral conductor and protective conductors. The utility model is characterized in that three corrugated main wire cores are equispaced on the outside of the neutral conductor and are concentric with the neutral conductor. An insulating layer is coated outside the main wire cores to form a cable core. The protective conductors are concentrically equispaced on the circumference of the cable core and are wound outside of the cable core. A metal wire current conducting wire is arranged along the cable core in longitudinal direction in order to connect the protective conductors into a whole. The utility model has round appearance and small size, can improve the power supply quality, and is favorable for the safe operation of a cable and relevant equipment.

Description

Protect the conductor lv power cable with one heart

The utility model relates to a kind of lv power cable.

Five traditional core lv power cables mostly are three master cores and become cable structure jointly with neutral conductor (N line) and protection conductor (PE line); and the screen that does not have Uniform Electromagnetic Field in the construction of cable element, the cable of this structure can produce more following problems when actual production, engineering design and operation of power networks:

1, for guaranteeing the roundness of cable, when stranding, must add numerous filling tapes, so the outside diameter of cable and manufacturing cost is bigger than normal;

2, have big electric current to flow through or during the short circuit of cable own, can produce high-intensity magnetic field when cable, the secondary circuit that these high-intensity magnetic fields can influence laying in one ditch is with instrument, instrument cable, thereby and makes it to produce signal distortion and cause the control system misoperation.

3, the cable of unshielded structure causes that easily the counterattack of thunder and lightning punctures;

4, the radius of electricity supply of cable is little, the voltage drop when having the three-phase imbalance load simultaneously;

5, in the system of power supply neutral-point solid ground, when ground connection being taken place, understand breaking out of fire or form higher step voltage when a phase insulation breakdown.

The purpose of this utility model is the problem at above-mentioned existence, designs a kind of novel concentric protection conductor lv power cable, this cable outward appearance rounding, and outside dimension is little, can improve power supply quality, helps the safe operation of cable and relevant device.

The purpose of this utility model is realized by the following technical programs:

The utility model is made of master core, neutral conductor and protection conductor, and the master core of three corrugation shapes is distributed on the neutral conductor outside, and outsourcing insulation constitutes cable core.The protection conductor is distributed on around the cable core with one heart, and is wrapped in the cable core outside.Vertically establish an one metal wire drainage thread along cable core, will protect conductor to be connected as a single entity.

The protection conductor is wire or metal tape.

Technical characterstic of the present utility model and good effect:

1, the construction of cable is stable, the outward appearance rounding;

2, can protect the zero potential of cable, not have potential difference between the cable core;

3, the outside diameter of cable is littler of 5%～8% than traditional five-core cable external diameter, thereby has reduced the cost of cable;

4, has the stronger anti-external world and self interference capability to external world;

5, reduced phase--the impedance of nulling loop, the sensitivity that improves protective device, the line drop when having reduced the threephase load asymmetric operation;

6, in electrical transmission network systems, when a phase insulation breakdown, will can not cause a phase grounded circuit, and can only form phase--protectiveness short circuit between zero conductor, effectively avoid occurring the dangerous step voltage and the possibility of breaking out of fire accident;

7, improved the lightning withstand level of cable;

8, compare with common cable, each phase conductor has than low and consistent just (contrary) preface reactance value, protect the conductor lv power cable in theory with one heart in 5%, and common cable is 15%～20%.

When 9, two kinds of structural cables all flow through zero-sequence current, protect the conductor lv power cable to compare with the 5th core of common cable with one heart, the former reactance value is much lower, only is 20% of phase line, and the latter is then up to 700%.

Below in conjunction with accompanying drawing the utility model is done further narration:

Accompanying drawing is a cross-sectional structure schematic diagram of the present utility model.

1 is neutral conductor, the 2nd among the figure, insulating barrier, the 3rd, master core, the 4th, insulating barrier, the 5th, insulation band, the 6th, protection conductor, the 7th, drainage thread, the 8th, insulation band, the 9th, oversheath.

As shown in the figure, the utility model is distributed on three corrugation shape master cores 3 around the neutral conductor 1, and concentric with neutral conductor 1, and peripheral hardware insulation band 5 constitutes cable core.Protection conductor 6 is distributed on around the cable core with one heart, and is wrapped in the cable core outside, vertically establishes a drainage thread 7 along cable core, and drainage thread 7 will protect conductor 6 to be connected as a single entity.

Claims

1, protects the conductor lv power cable with one heart; constitute by master core, neutral conductor and protection conductor; the master core that it is characterized in that three corrugation shapes is distributed on the neutral conductor outside; and it is concentric with neutral conductor; outsourcing insulation constitutes cable core, and the protection conductor is distributed on around the cable core with one heart, and is wrapped in the cable core outside; vertically establish an one metal wire drainage thread along cable core, will protect conductor to be connected as a single entity.

2, the concentric protection conductor lv power cable of narrating according to claim 1, it is characterized in that protecting conductor is wire or metal tape.