Method for preventing high tension power line single phase coinciding with permanent fault

Abstract

The method is used to prevent high-voltage transmission lines from single-phase reclosing in permanent fault. A grounding switch and a damping resistance are arranged between a neutral point reactor and the ground for a high-voltage transmission line, an extra-high voltage transmission line or an ultrahigh voltage transmission line which is equipped with a paralleling reactor and a neutral point reactor on one lateral or two laterals, and the grounding switch can be short connected with a part of reactance of the neutral point reactor through the damping resistance. The grounding switch is closed through an automatic reclosing device before a single-phase reclosing, and a part of reactance is short connected through the damping resistance. The level of oscillating voltage can be controlled through controlling the percentage of reactance value and the value of the damping resistance of the neutral point reactor which is short connected for a circuit line breaking phase with intact insulation. The insulting level of the breaking phase can be judged through detecting voltage of the circuit line breaking phase whether reaches the set voltage value or not, and the high-voltage transmission line, an extra-high voltage transmission line or an ultrahigh voltage transmission line is prevented from single-phase reclosing in permanent fault.

Description

technical field [0001] The patent of the present invention relates to the field of relay protection of electric power systems, in particular to a method for preventing reclosing from permanent faults during the single-phase automatic reclosing process after a single-phase ground fault of a high-voltage, ultra-high voltage or ultra-high voltage transmission line. Background technique [0002] In the operation of high-voltage transmission lines, most of the faults are single-phase ground faults. In order to ensure the reliability of the power system, single-phase automatic reclosing technology is widely used in high-voltage transmission lines. If the reclosing occurs in a permanent fault, the power system and power equipment will be impacted by short-circuit current again. For UHV lines, the negative impact of short-circuit current impact is greater. In the operation of ultra-high voltage transmission lines, shunt reactors are often connected. In order to easily extinguish th...

AI Technical Summary

Problems solved by technology

[0003] In order to overcome the single-phase grounding fault in the operation of high-voltage transmission lines, in the process of single-phase automatic reclosing, because it is impossible to judge whether the disconnected phase insulation after the single-phase trip of the fault has reached the level that can withstand the normal voltage, it cannot guarantee success. Problems in realizing single-phase automatic reclosing

Images