For decades, utility operators have been searching for a way to automatically conduct physical inspections of overhead transmission lines. Now, because of aging infrastructure, the need is greater than ever to identify potential failures before they disrupt service and require line personnel or electricians to make repairs.
Visual inspections are time-consuming, expensive and often fail to identify problems. Over the past few years, several robotic prototypes have been developed. Now, the Electric Power Research Institute (EPRI) is working with utilities to deploy a practical robot as early as 2013.
Nicknamed “Ti,” the new inspection robot is being tested in Lenox, Mass. It is designed to be permanently installed and automatically traverse 80 miles of transmission line twice per year, collecting information that can be used to make maintenance decisions. As it crawls along the line, it identifies high-risk vegetation and inspects the line conditions and components.
“It incorporates image recognition, LIDAR—laser light detection and ranging—infrared cameras to find hot spots; identifies electromagetic interference; and interfaces with wireless sensors deployed along the line that acquire transmission data,” said Andrew Phillips, director of transmission and substations research at EPRI.
Ti moves on rollers along the shield wire, which is installed above the transmission line, and traverses towers using bypass lines that are installed to accommodate the robot.
In early 2010, the demonstrator robot and bypass systems were built and tested. Tests proved the concept and provided inspiration for the overall design’s evolution.
Ti is battery-powered and recharged using a harvesting system that draws induced current from the shield wire of the transmission line. A top-mounted solar array provides backup power for motion and communication.
“We are planning to install Ti on the Potomac-Appalachian Transmission Highline (PATH), a joint venture of American Electric Power and Allegheny Energy,” Phillips said. “The 765-kilovolt, 283-mile line should start construction and be phased in during 2013 to 2014. We plan to be part of that construction project and install two, possibly three robots to inspect the entire line.”