How drones are used by electricians

Drones offer safety to electricians 

Electrical work is considered one of the riskiest jobs. The most obvious risk is that of electrocution. An electric shock received from a high-voltage transmission line can immediately prove to be fatal. Besides the threat of shocks, while inspecting power lines, there is also the risk of falling from heights. Drones are being used to reduce the risk factor significantly in either scenario. Here are a few situations where drones have been used to reduce hazardous man-hours[1].

Surveying storm damage 

A heavy storm can uproot electrical poles and break transmission lines. In areas where the transmission line is close to vegetation, an uprooted tree following a storm will inevitably disrupt the power supply. Earlier, it could have taken several days to run an inspection along the power line and locate the fault, especially a problem in remote areas.

A drone, on the other hand, can complete the task effectively within a few hours. Based on the images and video footage received from the drone, an electrical service provider, such as CLF Services, dispatches its technicians to look after the matter. In addition, drones equipped with infrared vision can be used to assess storm damage even at night. This can help in the fast restoration of power[2].

Storm damage drone usage

General maintenance of transmission lines

Regular inspection of transmission and distribution lines is critical. This effectively helps in identifying problems at the root and preventing them from turning into anything major. These inspections are sometimes conducted aerially from a helicopter, or through manually checking the power lines. Drones can get the job done at a mere fraction of the costs incurred in hiring a helicopter. There is no need for manual inspection using trucks.

The use of drones can also help get rid of presumptions. Sometimes, CLF Services’ electrical workers falsely assume that new lines are fault-free, and the problem lies with older transmission lines. This results in non-uniform inspection, devoting more energy to old lines, and neglecting newer installations. However, practical experience shows that new lines are equally prone to faults. In fact, at times, one may find that a ten-year-old line is about to break down while a forty-year-old line is in excellent condition. Since drones are so easy to use, inspections of the entire line, be it old or new, become much simpler.

Furthermore, drones are highly effective when the inspection has to be done in difficult terrains. Sometimes, power lines traverse through private properties, where it can take hours to obtain permission for manual inspection. A UAV can do the work without fuss. The same goes for inspecting power lines passing over main thoroughfares. In this instance, CLF Services would seek permission from councils so that the traffic can be stopped or diverted to allow for inspection work. The drone simplifies the entire process.

Drones are cost-effective

If the inspections are to be carried on by helicopters, it is usually going to cost thousands of dollars every day. By buying a few drones at a fraction of the cost, everything can be done in a highly cost-effective manner. Electrical providers can also save the cost of hiring manpower and expensive equipment to do inspection work.

Lengthy disruption of electrical supply can be a costly exercise for businesses. Drones can help with timely repair, effectively saving thousands of dollars.

Cable route planning

The pre-planning phase of laying electric cables would otherwise take up a lot of time and effort if not for the drones. A drone can easily traverse great distances and offer a comprehensive review of the local topography before laying the cables. It can help decide the ideal route for the installation of power lines without interfering with private properties or train lines along the way.

With advanced equipment used in drones, you can not only get a visual representation of the topography but also calculate depth and distance between successive points[3]. Modern UAVs can come equipped with laser scanners which can help map the route of electrical cable installation through a densely wooded area[4].

Renewable energy inspections

Drone inspections are proving to be extremely effective for inspecting solar panels and wind turbines. The typical way to inspect a solar PV panel is to take a heat map and see if all the cells are functional. However, manually taking the heat map usually fails to get an accurate result because the shadow of the person handling the equipment blocks a certain section of the cells. Since a drone can capture heat maps from above, it can give a clear idea about the status of the PV cells. [5] Even for an assessment of rooftop spaces to install solar panels, drones have proven to be of significant use[6].

As for wind turbines, these are often placed on elevated locations such as the top of a hill. The turbines themselves are huge apparatuses stretching several meters vertically. Climbing the wind turbines for inspections is a hazardous affair as there is always the risk of heights. A drone simplifies the entire process by covering a detailed inspection of the turbine from all angles.

Wind turbine

Limitations of the drone

The drones described here can only do inspection work and identify faults in the transmission lines. Once the faults have been located, electrical workers still have to use the traditional methods to climb the pole and handle repairs. The risk of heights and accidental electrocution remains.

Threats posed to drones

It is imperative to follow certain precautions while handling drones. Companies must ensure that drone operators, or pilots, have adequate training to handle them. Here are a few risks posed by drones.

● They must be kept at least 30–50 metres from the power lines and electrical substations. The high-voltage electricity passing through these lines can interfere with the radio signals of the drone. This can cause them to crash, damaging power lines, electrical equipment, or hitting a person on the ground.[7]

● An operator may get electrocuted while retrieving a drone that has been tangled in the power line.

New technology also helps in repair

In at least a few reported cases across the world, drones are also being used to handle repair work directly. In one such incident reported from China, a drone was used to conduct a speedy repair on a live power transmission line. A previous aerial inspection revealed that a bolt had become loose in the transmission line. If it were not repaired immediately, there was the risk of serious damage to the transmission line.

A drone was used to lift and suspend some insulated cables from the power line. This was followed by manual work from an operator equipped with an insulated suit specifically for working on high voltage lines. It took the worker only half an hour to conduct the repair work without even disrupting the power supply. It is estimated that without the drone, it could have taken up to six hours, along with a disruption in the power supply[8].

The evolution of drone technology

Drone technology has evolved considerably in the last few years. As for which type of drone is best for electrical inspection, there are a few different considerations. Here are the different types of drones and their unique properties. Electrical operators keen on employing drones should consider these aspects to make informed decisions.

Multi-rotor drones

These represent the first stage of drone evolution. They consist of four rotors and are also called quadcopters. They move like a helicopter but may not be suitable for covering large distances before the battery runs out. They are ideal for flight times of 20 to 30 minutes. They are also the cheapest type of drones. They are not considered highly energy efficient as they require a lot of power to stay afloat. These also have lesser speed compared to the other types.

Multi rotor drone

Fixed-wing drones

These are small aeroplanes operated from the ground. They have fixed wings at the sides, which helps them to stay afloat. They can cover larger distances and are suitable for mapping wider areas. However, their major problem is the inability to hover at a single spot. Data capture and processing through these devices also takes additional time. Piloting them is also a much trickier job, and one needs a lot of practice. In contrast, practically anyone can fly a multirotor drone.

Another problem unique in Australia is that these drones are often attacked by Wedge-tailed eagles. If you fly a fixed-wing drone in rural areas at a height of 100 m, these birds of prey are often known to attack and damage them[9].

Fixed wing drone

VTOL drones

The Vertical Takeoff and Landing drones are still largely in the developmental stage. They combine design elements of both fixed-wing and multi-rotors. These can take off and land vertically just like a quadcopter, and work just like a fixed-wing drone[10].

Final words

As drones continue to evolve, they are proving to be of great practical usage to electrical operators. The scenario in Australia continues to be encouraging as several companies have started using drones for aerial inspection. Brisbane-based CLF services have proven to be pioneers in implementing drone use for electrical maintenance work. Give them a call to conduct an aerial survey of electrical problems in your property.

Sources:

[1] https://www.measure.com/drones-in-transmission-distribution-utilities

[2] https://www.tdworld.com/overhead-transmission/article/20973069/flying-high-drones-find-many-applications-in-the-electric-power-industry

[3] https://www.smithbrothersltd.co.uk/news/2019-03-22-how-the-use-of-drones-is-changing-the-electrical-engineering-industry

[4] https://www.newscientist.com/article/mg22530142-100-drones-cleared-to-check-power-lines-after-outages/

[5] https://www.powerengineeringint.com/gas-oil-fired/om/how-drones-are-playing-a-role-in-the-power-and-utility-sector/

[6] https://economictimes.indiatimes.com/industry/energy/power/discoms-use-drones-for-effective-maintenance-of-power-distribution-infrastructure-in-delhi/articleshow/74226204.cms?from=mdr

[7] https://www.indianaec.org/2020/05/27/drones-pose-electrical-safety-issues/

[8] http://www.xinhuanet.com/english/2020-07/06/c_139192399.htm

[9] https://www.auav.com.au/articles/drone-types/

[10] https://www.propelleraero.com/blog/fixed-wing-vtol-drones-vs-quadcopters-for-surveying-how-to-decide/