Power supply cable for low-voltage frequency conversion

Abstract

Provided is a power supply cable for low-voltage frequency conversion. The cable comprises a cable core, a lining layer, a shielding layer, a fireproof isolation layer, a wrapping layer and a sheath layer which are arranged in sequence, and the cable core comprises three first wire cores and three second wire cores. The three first wire cores are distributed in the cable core along the circumference; the three second wire cores are distributed on the periphery of the three first wire cores along the circumference, the diameter of each first wire core is larger than that of each second wire core, the fireproof isolation layer is arranged between the shielding layer and the sheath layer, the wrapping layer is arranged outside the fireproof isolation layer, and the fireproof isolation layer comprises a polygonal PE isolation sleeve and a fireproof mud layer which wrap the shielding layer. The power supply cable can bear pulse voltage during high-speed frequent frequency conversion, and plays a role in protecting a variable-frequency electric appliance; the fireproof mud layer is added on the basis of the fireproof cable, so that the bending radius of the cable is not increased when the cable encounters a fire, the operation and laying of the cable are more convenient, the operation time of the cable is longer when the fire occurs, the destructive power influenced by the fire is smaller, and the operation of the cable is more stable.

Description

technical field [0001] The invention belongs to the technical field of cables, in particular to a power supply cable for low-voltage frequency conversion. Background technique [0002] In recent years, with the continuous development of the global economy and the large increase in demand for resources, the industries of metallurgy, metal processing, mining, railways, papermaking, and food processing are increasing day by day, and the production capacity is continuously increasing. Reduced manufacturing costs, especially in metallurgy and mining industries, so frequency conversion devices and frequency conversion cables have been widely used. The energy-saving effect of the frequency conversion device is very significant. The frequency conversion speed regulation motor is used in the high-power motor, and the entire generator set can save electricity by 20%-30%. After using the frequency conversion speed regulation motor, the soft start of the motor is realized to make the mo...

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Problems solved by technology

[0004] However, the existing frequency conversion cables have the following problems: 1) most of them adopt total package shielding and 3+1 structure, and the anti-pulse ability is limited during high-speed frequency conversion; 2) due to the special environment of frequency conversion cables, especially in metallurgy, mining In the mining and papermaking industries, the fire-resistant and fire-proof functions of cables are more important. At present, various manufacturers are constantly exploring and developing more effective solutions or superior product structures, but they have not achieved the expected results; 3) The flame-retardant of frequency conversion cables Performance and environmental protection requirements are getting higher and higher, how to solve the problem becomes the key, flame retardant PE or flame retardant PVC material, for the bundled flame retardant Class A combustion test, the flame retardant performance can be improved by adding the amount of flame retardant, The frequency conversion cable has a large number of cores and a large outer diameter. It is difficult to pass the Class A combustion test of the bundled flame retardant. If too much flame retardant is added in the flame retardant material, the mechanical performance index of the material will be greatly reduced. The mechanical properties after aging are difficult to pass, so the cable will crack during bending and stress, and the sheath will age significantly during operation, which will affect the service life of the cable

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