Medium-voltage variable-frequency power cable matched with high-performance high-capacity frequency converter and preparation method thereof

Abstract

The invention provides a medium-voltage variable-frequency power cable matched with a high-performance high-capacity frequency converter and a preparation method of the medium-voltage variable-frequency power cable. The medium-voltage variable-frequency power cable comprises a main conductor wire core, a neutral conductor wire core, an isolation strip layer, an inner sheath, a composite metal total shielding layer and an outer sheath, the main conductor wire core comprises a main conductor, a conductor shielding layer, an insulating layer, an insulating shielding layer and a split-phase metal shielding layer. The conductor shielding layer is composed of a semi-conductive belt and a semi-conductive extruded layer. The insulating layer is extruded outside the semi-conductive extruded layer; the insulating shielding layer is extruded outside the insulating layer by adopting a semi-conductive shielding material; a semi-conductive belt is also wrapped outside the insulation shielding layer to form a semi-conductive belt insulation shielding layer; the split-phase metal shielding layer adopts a dual-combination split shielding structure; the neutral conductor wire core is composed of a neutral conductor and a semi-conductive layer. The medium-voltage variable-frequency power cable can bear continuous pulse overvoltage and neutral current components in a variable-frequency power source, has high electromagnetic shielding performance and reduces high-frequency electromagnetic wave interference.

Description

technical field [0001] The invention relates to the technical field of power cables, in particular to a medium-voltage variable-frequency power cable for supporting high-performance and large-capacity frequency converters and a preparation method thereof. Background technique [0002] All aspects of equipment and control systems included in frequency conversion speed regulation technology, such as frequency conversion motors, frequency converters, etc., have reached a very high level at home and abroad, especially low-voltage frequency conversion speed regulation technology is becoming more and more mature. With the development of modern industry, high-performance and high-power motors continue to appear, and the speed regulation of medium-voltage motors has become a problem that must be solved. Power transmission cables and medium-voltage frequency conversion cables are still in the research and development stage. [0003] At present, the connection cables between the medi...

AI Technical Summary

Problems solved by technology

However, the output power of the frequency converter contains third or even higher harmonics, because there is no phase difference in the high-order harmonic current components, so in the neutral line, these high-order harmonic current components are directly superimposed to several times the original, resulting in It cannot carry the neutral current component in the variable frequency power supply. Long-term use will easily cause serious heating of the neutral line, accelerated aging, and even breakdown

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