Copper-strip-shielded type cross-linked-polyethylene-insulated polyvinyl-chloride-sheathed medium voltage cable

Abstract

The invention discloses a copper-strip-shielded type cross-linked-polyethylene-insulated polyvinyl-chloride-sheathed medium voltage cable with long service life, high safety and large leakage current. The medium voltage cable comprises one or three cable cores, a filler yarn (7), a bare conductor (6), a brass strip (8), a wrapping tape (9) and an outer sheath (10), wherein each cable core comprises a conductor (1) used for wrapping an inner shield (2), an insulation layer (3), an outer shield (4) and a copper strip shield (5) sequentially from inward to outward; the conductor, the inner shield, the insulation layer, the outer shield and the copper strip shield form the cable core; the filler yarn (7) is arranged between the cable cores; the bare conductor (6) is arranged in the filler yarn and between the two adjacent cable cores; the brass strip (8) is used for wrapping all the cable cores, the filler yarn (7) and the bare conductor (6); the wrapping tape (9) is used for wrapping the brass strip (8); and the outer sheath (10) is used for wrapping the wrapping tape (9). The medium voltage cable provided by the invention has the advantages that the service life of the cable is prolonged, the fault rate of the cable is decreased, the current leakage capacity is improved, and short-circuit accidents caused by electric heating breakdown of the cable due to accidental large current such as lightning strokes and the like are reduced.

Description

technical field [0001] The invention belongs to the field of cables, in particular to a medium-voltage cable with copper tape shielding XLPE insulated polyvinyl chloride sheath with high service life, high safety and large leakage current. Background technique [0002] At present, my country is vigorously developing XLPE insulated cables, because XLPE insulated cables can greatly increase their service life. However, under the condition of medium voltage, under the action of the electric field, the accumulation of space charges is caused, which seriously deteriorates the conductivity of the insulating material medium, and finally causes the electric field distribution of the cable insulation layer to exceed the maximum electric field strength allowed for safe operation of the cable, resulting in cable failure. Breakdown, thereby reducing the service life of the cable. In addition, in places with many thunderstorms or excessive external current, it will cause cable overcurre...

AI Technical Summary

Problems solved by technology

However, under the condition of medium voltage, under the action of the electric field, the accumulation of space charges is caused, which seriously deteriorates the conductivity of the insulating material medium, and finally causes the electric field distribution of the cable insulation layer to exceed the maximum electric field strength allowed for safe operation of the cable, resulting in cable failure. breakdown, thereby reducing the service life of the cable

In addition, in places with a lot of thunderstorms or too much external overcurrent, it will cause cable overcurrent insulation breakdown and cause cable failure

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