Method and system for locating grounding fault of power transmission line

Abstract

The invention discloses a method for locating a grounding fault of a power transmission line. The method comprises the following steps that a signal injection module injects an excitation signal withthe frequency different from that of a power grid into the power transmission line; a signal response detection module detects the voltage and the current of the excitation signal at the injection endof the excitation signal, and calculates an imaginary part of the complex impedance of a line loop under the condition that the excitation signal is injected, i.e., a reactance value, and multipliesthe reactance value by a proportional constant to obtain the distance between the injection position of the excitation signal and a fault point. Therefore, the method can be used for directly detecting whether the power transmission line is grounded or not so as to judge whether a closing condition is met or not, and can also be used for judging the electrical distance of a grounding point when the grounding condition is met, so that the grounding point can be conveniently and quickly found in time and eliminated. The invention also discloses a system for locating the grounding fault of the power transmission line.

Description

technical field [0001] The invention relates to the field of power systems, in particular to a method and system for locating a ground fault of a power transmission line. Background technique [0002] The hanging ground wire is a safety barrier to protect the maintenance personnel and the lifeline of the electric power employees, which can prevent the harm to the human body caused by a sudden call. However, in actual work, due to the frequent use of the ground wire and the seemingly simple operation, it is easy to paralyze people's minds, and its importance is often overlooked by people. Incorrect use often occurs, which reduces or even loses the safety of the ground wire. The protective effect must be paid enough attention to. During line maintenance, how to ensure that the grounding wire is effectively connected, in addition to following the safety regulations for correct operation, it is also hoped that there will be obvious and intuitive means of judging the connection ...

AI Technical Summary

Problems solved by technology

This kind of anti-misoperation device has a certain effect, but there are two problems: one is that it can only identify the grounding switch, but it can't do anything to the temporarily overlapped grounding wire; the other is that this type of device depends on the correct detection of the status of the switch device and smooth communication channels, the system structure is relatively complex, and reliability is difficult to guarantee

This kind of anti-misoperation device has a certain effect, but there are two problems: one is that it can only identify the grounding switch, but it can't do anything to the temporarily overlapped grounding wire; the other is that this type of device depends on the correct detection of the status of the switch device and smooth communication channels, the system structure is relatively complex, and reliability is difficult to guarantee

This device has a simple structure and strong practicability. However, due to different voltage levels and different lengths of line parameters, it is difficult to indicate whether there is grounding only by whether the "light" is off or not.

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