Common fault prevention measures for overhead transmission lines

The overhead cable line is an important transmission and distribution link, and its stable operation is an important factor affecting the safety and stability of the overall transmission and distribution network.

Only overhead cable transmission lines ensure stable operation to achieve increased reliability of power supply lines.

Under the influence of external unstable factors, overhead lines are easily affected in the external exposed environment and thus faults occur frequently.

Summary of common faults in Overhead Lines

• Single-phase ground fault

Single-phase grounding fault causes are mainly channel and line factors.

The channel as well as the connection line near is easy to close to trees, especially in the windy thunderstorm weather, the suburban overhead line connection is more likely to do so.

So once in contact with tree branches, it also easy to leads to a single-phase grounding fault occurred.

And there are bird damage factors.

Many birds choose to nest on the crossbar of the overhead line, once encountered in rain and snow, thus triggering the occurrence of a single-phase ground fault.

The impact of the overload factor is also one of the faults causes that needs attention. 

Summer often overload peak electricity season, and many of the circuit wire ends are easy to burn off because of aging, resulting in the occurrence of single-phase grounding fault.

• Short Circuit Failure

Short-circuit fault causes are mainly foreign body impact factors.

In the overhead lines around the air life garbage hanging to the line is caused by short-circuit fault generation.

There are also natural factors of lightning.

Because most of the buildings in the city have good lightning protection measures, the city is very good to happen overhead lines of lightning caused by short-circuit phenomenon.

But in many places in the suburbs, because the overhead lines are in the open environment, lightning will trigger a sudden increase in voltage, which can easily lead to the air insulation of overhead lines with lightning breakdown, triggering the occurrence of short circuits.

Bird damage factor, in the single-phase ground fault, occurs easily because of birds nesting triggered fault.

Not only that, birds often used to stay collectively on the insulated overhead power line.

If a tree branch is bridged between two lines, making the external connecting conductor between the two lines, it can easily lead to a phase-to-phase short circuit.

Equipment factors, the line itself will also come down because the arc sag is too large or continuous operation time is too long will lead to connected insulation performance decline, thus further leading to short-circuit fault occurrence.

• Broken Wire Fault

Breakage fault causes external factors, overhead lines are easy in the impact of vehicles and construction of accidental damage, etc. triggered by overhead line breakage.

Lightning factors, in the lightning instantaneous electric shock process, for bare wire and insulated wire easy to lead to a large amount of heat generated, in this role it is easy to lead to automatic fusing of the wire, thus triggering a breakage fault.

In the case of insulated conductors, the process of instantaneous lightning strikes can easily cause two-phase and three-phase different conductors and lines between the instantaneous flashover.

Similarly, the arc will be in the role of the power supply magnetic force and the role of the thermal effect of electricity to produce negative charge transfer, the concentration of the arc area will be easy to ignite, resulting in the wire eventually breaking.

Common fault prevention measures for overhead lines

Conduct regular inspections of cable lines and hardware facilities, sweep the connection pathways of the lines, and prevent debris from triggering connection faults.

Take precautions against damage by external forces and set up safety tips at locations susceptible to vehicle impact.

When there is construction going on around the line, timely contact with the construction unit to strengthen line monitoring.

At the same time, should set up a joint management system of police and enterprises to combat the occurrence of theft of line equipment.

Also to further strengthen the protection of electric power facilities publicity, increase awareness of the protection of electric power equipment.

Lightning protection measures, lightning generation will trigger a sudden increase in voltage, which can easily lead to the air insulation of overhead lines with lightning breakdown, triggering the occurrence of short circuits.

Lightning rods and oxide arresters should be installed in a timely manner.

The resistance of the grounding device is regularly checked and recorded to ensure that the safety monitoring of the circuit lines is in place.

Set up bird-proof devices and strengthen regular inspection and testing.