Method for reducing insulation overhead ground wire induction voltage of alternating current transmission line

Abstract

The invention relates to a method for reducing the insulation overhead ground wire induction voltage of an alternating current transmission line. The method comprises the following steps that the insulation overhead ground wire induction voltage limit value U<0> and the circuit current I are determined; when an insulation overhead ground wire grounding point is selected to be at one end part, the insulation overhead ground wire transposition pitch 1<0> is calculated to be (8-15)*U<0>/I<km>, and a nearby tension rod tower is selected every ten points from the end part of an insulation overhead ground wire as transposition nodes for carrying out ground wire transposition or conducting wire transposition; and when the insulation overhead ground wire grounding point is positioned between two ends of the insulation overhead ground wire, the insulation overhead ground wire transposition pitch 2*1<0> is calculated to be (16-30)*U<0>/I(km), the nearby tension rod tower is selected every 2*1<0> from one end part of the insulation overhead ground wire as transposition nodes for carrying out ground wire transposition or conducting wire transposition, and in addition, the insulation overhead ground wire grounding point is arranged nearby the half transposition pitch of one transposition node. The method has the advantage that the induction voltage can be reduced to be within the set induction voltage limit value U<0>.

Description

technical field [0001] The invention relates to a method for reducing the induced voltage of the insulating overhead ground wire of the AC transmission line, which can reduce the induced voltage of the insulating overhead ground wire of the AC transmission line to any limit value U 0 within. Background technique [0002] At present, the insulated overhead ground wire mainly adopts the method of full-line insulation or single-point grounding. When the overhead ground wire of the transmission line is fully insulated, the induced voltage of the insulated overhead ground wire of the 500kV transmission line is above 40 kV, and the voltage of the 220kV transmission line is above 30kV. When the insulated overhead ground wire (same as the above-mentioned insulated overhead ground wire) is single-point grounded, the induced voltage on it increases with the length of the insulated overhead ground wire, and generally can reach thousands of volts. Excessively high insulated overhead gr...

AI Technical Summary

Problems solved by technology

Excessively high insulated overhead ground wire induction voltage may cause faults such as misdischarge in the protection gap of the ground wire insulator and burn the protection gap of the ground wire insulator, and it is also easy to cause wireless interference to external radio signals, and it is also not conducive to the live work of the staff on the tower

[0003] Although the above-mentioned induced voltage can be reduced by transposition of wires and ground wires, due to the lack of a scientific calculation method for the transposition pitch, there are large differences in the induced voltage values ​​of insulated overhead ground wires in various regions, which limits the protection gap of ground wire insulators. The setting of the distance is inconvenient

If the distance of the protective gap of the ground insulator is not set properly, the protective gap of the ground insulator may be misdischarged, and it may also be difficult to extinguish the arc due to the high recovery voltage of the protective gap. In severe cases, the protective gap of the ground insulator may be burned , and even cause the ground wire insulator to burst

In addition, due to the lack of a unified value for the induced voltage of the insulated overhead ground wire, the workers on the tower have a vague understanding of the induced voltage of the overhead ground wire, which may easily lead to safety accidents

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