Extra-high voltage DC grounding electrode circuit protection system

Abstract

The invention provides an extra-high voltage DC grounding electrode circuit protection system, comprising a tower body, and a lightening conductor cross arm and a grounding electrode wire cross arm on the tower body, lightening conductors respectively fixed on two ends of the lightening conductor cross arm, and grounding electrode wires respectively fixed on two ends of the grounding electrode wire cross arm through an insulator S1 and an insulator S2. The connecting end of the grounding electrode wire and the insulator S1 is connected with one end of a gap C1. The connecting end of the grounding electrode wire and the insulator S2 is connected with one end of a gap C2. The other end of the gap C1 and the other end of the gap C2 are connected with one end of a lightning arrester. The other end of the lightning arrester is connected with the tower body. The technical scheme can reduce accidents of unipolar and even bipolar locking caused by arcing horn flashover of an extra-high voltage DC grounding electrode circuit, and realizes that one lightning arrester can protect two grounding electrode circuits, and ensures correct operation of unbalanced current protective equipment and grounding electrode circuit broken line detection protective equipment, and the system is not influenced by lightning arrester ground capacitance.

Description

technical field [0001] The invention relates to a protection system, in particular to a lightning and operation overvoltage protection system for an UHV DC grounding electrode line. Background technique [0002] The existing ±800kV and ±1000kV UHV DC grounding electrode lines generally adopt the method of insulators connected in series and parallel to prevent lightning and operating overvoltage from causing damage to the line; The fit coefficient is 0.7-0.85. Under lightning strike or operating overvoltage, the arcing angle flashes ahead of the insulator string, so that the DC continuous current flows through the arcing angle instead of the insulator string, so as to prevent the arc from burning out the insulator string, causing string drop, and It is beneficial to the DC current arc extinguishing on the arc striking angle. [0003] However, the discharge characteristics of the striking arc angle and the extinguishing characteristics after flowing the operating DC current ...

AI Technical Summary

Problems solved by technology

Operation experience shows that the ±800kV grounding electrode line has repeatedly caused single-pole or even double-pole blockage due to flashover of the arc angle, or major accidents where the arc angle cannot be extinguished and continues to burn until the arc angle is burned, and insulators are dropped.

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