Inspections of overhead power lines

Overhead power lines (overhead lines) are used to transmit electricity from a power source to consumers. In order to prevent emergency situations and, as a result, interruptions in the power supply to consumers, it is necessary to check the power lines in a timely manner and, if necessary, immediately eliminate the detected malfunctions. Consider when the inspection of power lines is carried out and how it should be carried out.

Scheduled periodic inspections of air lines

An enterprise that maintains overhead power lines, composes special line inspection schedule.

Overhead power lines should be reviewed at least once a year, but depending on the reliability category of the user, climatic conditions, the current technical condition of the line, additional checks of the lines can be organized. Also, the inspection schedule additionally includes sections of power lines that to be repaired in the near future.

Inspections of overhead power lines are periodically carried out in order to promptly identify malfunctions, etc."Weak spots" that can cause automatic shutdown of the power line.

Also during line inspections pay attention on trees, bushes, the branches of which can reach the conductors and provoke them to collide and, as a result, a phase-phase short circuit or a conductor falling to the ground-short circuit to the ground. Special attention is paid to emergency trees, as well as buildings and structures that can fall on the wires at any time and damage the overhead power line.

The results of the check are recorded to a special log of bypasses and line inspections or to a log of equipment defects.

If, as a result of the inspection, signs of malfunction are found along the line, the presence of emergency trees or branches overgrown near the wires, then it is necessary to take appropriate measures to prevent the occurrence of an emergency situation. For this purpose, an application is submitted in advance, within the prescribed period, for the disconnection of one or another power line. If surgery is required, an urgent (urgent) application is submitted.

Unscheduled line checks

Unscheduled (unscheduled) checks are carried out after automatic shutdown of air lines, after failure automatic reclosing, after various natural disasters, a fire in the area of ​​the route of the line, as well as with the possibility of icing on the wires.

In the event of an emergency shutdown of the overhead line, an inspection of the line is first organized to identify the damaged section.

The elimination of accidents in an enterprise that supports electrical networks is carried out by specialized brigade… The number of employees, the number of special equipment is determined based on the number and length of overhead lines.

In this case, it is also taken into account consumer power category... If the user's working conditions are such that a prolonged interruption of the power supply can lead to negative consequences, accidents and a threat to human life, then the enterprise must be able to search for and eliminate accidents on power lines that have occurred. This task is performed by exit task force.

How the inspection of overhead power lines is carried out

When inspecting overhead lines, pay attention to:

• the condition of reinforced concrete and metal supports, foundations of metal supports, their digging into the ground, as well as the absence of indentation or subsidence of the soil near the supports; — the integrity of wires, insulators and the reliability of their attachment to various elements of linear fittings;

• the presence of numbering of supports, prohibition signs and sending names of the power line in accordance with the requirements of the PUE and other regulatory documents in force in the enterprise serving the overhead line;

• the absence of foreign objects on the supports and wires of the overhead line, the absence of emergency trees and vegetation that can damage the power line;

• compliance with the requirements for the protection zone of power lines. In the security zone of the power line, construction, installation and earthworks are prohibited, it is prohibited to place combustible materials and various elements that may disrupt the normal operation of the electrical network.

Inspection of overhead lines is carried out by a ground method, where it is possible to identify most of the possible line failures. But there are damages that cannot be detected by the ground method, therefore, if necessary, riding inspections of overhead lines are carried out. Inspections of horses for damage are carried out selectively, in areas where damage is most likely.

Horse inspections are carried out use of aerial platforms or unmanned aerial vehicles (UAVs), which greatly simplifies the line inspection process. Depending on local conditions, the inspection of an overhead power line can take up to several days, and the use of UAVs can significantly reduce the time it takes to inspect the line and search for a damaged section.

In addition, to simplify the search for a damaged area of ​​an overhead power line, data for relay protection devices... Modern protective devices allow to determine with high accuracy the place of damage to the power line: of microprocessor devices for relay protection and automation after the line is interrupted by the protection action, the distance to the location is recorded to the nearest tenth of a kilometer. Also this feature is in emergency recorders.

According to the recorded data of the measuring devices at the time of failure, through the triggered protections, you can find out type of damage.

Thanks to the availability of this information, considerable time is saved in searching for faults, which is especially important for long power lines. Instead of a 50-100 km inspection of the line, the repair team goes to a known section of the line and finds the damaged section within 100-200 m.