The University of KwaZulu-Natal has collaborated with Eskom to design, manufacture and deploy a robotic vehicle that transports inspection sensors along transmission-level power lines. We're working together to provide this new way of inspecting lines, ultimately to help ensure the security of electrical supply.
Overhead power lines are valuable assets that are exposed to harsh environmental elements. Over time, problems with the lines and support structures start to show. Damage to insulators, broken or bird-caged conductors, and corroded hardware, are just some of the symptoms of aging infrastructure. Managing the repair of this damage on a grid that spans vast distances is costly and challenging, and the way that maintenance is carried out can affect the reliability of the electrical supply.
Inspection of power lines is a crucial step in making maintenance decisions. These Inspections are carried out regularly to try and find damage early, before it threatens the supply. Currently, most power line inspections are performed by aerial or foot patrols, and these methods can have difficulties in collecting relevant data in a manner that is consistent, inexpensive, and low-risk. As examples, inspectors on the ground might struggle to access right-of-way due to terrain or private land, and are unable to see parts of the towers. Inspectors being transported by helicopter trade expensive flying time for inspection detail. Assessments on core corrosion and splice resistance are done by linesmen on the line, which is inherently dangerous.
Working with South Africa's power utility Eskom, the University of KwaZulu-Natal is developing an alternative method of power line inspection, using a mobile robot that will transport inspection sensors around the transmission grid. The robot rolls along power lines and may traverse multiple spans of line by overcoming towers and other line hardware.
The robot will improve on current inspection methods by being cheaper, safer, less intrusive, and able to provide more detail. By being mounted to the conductor, the platform is stable, energy-efficient, and has a well-defined right-of-way passage. As a result, use of expensive helicopters may be reduced, and deploying linesmen onto the line may become unnecessary. The robot can provide very close views of the hardware of interest, from viewpoints that are not possible from off the line. With appropriate sensors fitted, the robot will be able to provide inspection data for assessments that include visual for conductor and tower hardware, ultraviolet and infrared for insulation and conductivity, magnetic mapping for steel core, and Lidar and visual for right-of-way.
THE BIG PICTURE
The ultimate long-term benefit of using robotic technology for line inspection could see the improvement in the quality of electricity supply due to improved transmission asset management. The power line robot is capable of delivering more detailed inspections which will enable inspectors to find damage earlier than before. This ability will allow asset managers to track the progression of damage and optimise the deployment of maintenance teams.