High-voltage cable metal sheath circulation model and model establishing method

Abstract

The invention provides a high-voltage cable metal sheath circulation model and a model establishing method, and belongs to the technical field of electric power. The objective of the invention is to based on a single-core high-voltage cable engineering crossing grounding mode, establish a high-voltage cable metal sheath circulation model and a model establishing method of a grounding current mathematical calculation model of a single-core cable under a crossing interconnection grounding mode. The method comprises steps of establishing an equivalent circuit of a transposition section loop of the cable metal sheath crossing interconnection; constructing an equivalent circuit which is equivalent to an actual system; according to a circuit principle, by use of a loop voltage method, listing and writing an equation set of the equivalent circuit; and finally, solving the magnitude of grounding current of each phase of the metal sheath. According to the invention, by applying the designed high-voltage cable metal sheath circulation model into the current electric power system, the current high-voltage current circulation problem can be efficiently solved, so the current carrying capacityof the cable is greatly improved; normal operation service lifetime of the cable is prolonged; and occurrence of the accident is reduced.

Description

technical field [0001] The invention belongs to the technical field of electric power. Background technique [0002] The relationship between the wire and the metal sheath of a single-core power cable can be regarded as the primary winding and secondary winding of a transformer. When the cable conductor passes current, a magnetic flux is generated around it, and the magnetic flux is not only linked with the core circuit, but also linked with the metal sheath of the cable, and induced potentials are generated on the wire core and the metal sheath respectively. For a single-core cable, each core has a dedicated metal sheath, and the magnetic flux generated by the load current or short-circuit current is interlinked with the metal sheath, so the induced voltage on the metal sheath always exists. The value of this induced voltage is related to the cross section of the wire core, the distance between the cables, the magnitude of the current and the length of the cable. Especial...

AI Technical Summary

Problems solved by technology

Therefore, seeking a model and solution method that can accurately and conveniently calculate the circulating current of the high-voltage cable metal sheath is a technical problem that those skilled in the art have always wanted to solve, but so far, it has not been solved.

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