Chongqing—On the morning of September 7, a rail-mounted robot autonomously began its daily inspection in a tunnel located six meters underground in Chongqing, China. Upon receiving a remote command to inspect, the robot traversed the tunnel, continuously monitoring environmental conditions such as temperature, gas levels, and potential irregularities and sending data back to a central system.
On September 7, State Grid Chongqing Ultra-High Voltage Company used a rail-mounted smart inspection robot to inspect a 220 kV cable tunnel. (Photo/Cui Yao)
Underground cables form the critical arteries of urban power grids, connecting substations and supplying electricity to both residential and industrial users. The stable operation of these cables is crucial to ensuring uninterrupted power delivery. Even in cooler weather, when electricity usage is lower, inspections must remain rigorous to avoid potential disruptions.
The smart inspection robot isn't just a routine checker; it is equipped with a retractable mechanical arm that can extend to equipment and capture high-definition images of key monitoring values. These images are sent back to the system for real-time analysis, enabling maintenance personnel to detect even the slightest anomalies.
"This system is like installing a smart brain in the tunnel," said Yu Li, an employee at the State Grid Chongqing Ultra-High Voltage Company's Cable Maintenance Center. He added, "The robot autonomously inspects once a month under normal conditions, with daily inspections during the peak summer period, ensuring early detection and prompt resolution of potential risks."
Meanwhile, another inspection robot operates in a 220 kV cable tunnel in the Yubei District, about 9 meters underground. Equipped with infrared temperature sensors, gas detectors, and cameras, the robot dog moves steadily through the tunnel, inspecting cable conditions and environmental factors in detail.
The robot dog integrates an AI host, sensing modules, and movement controllers, allowing it to perform scheduled inspections or respond to urgent, remote commands. "This 'steel dog' is both flexible and reliable," said Yin Yecheng, deputy team leader at the Cable Inspection Center of State Grid Chongqing.
Yin explained, "The data it sends directly connects to the cable management platform, streamlining the process from data collection to analysis and decision-making, significantly improving inspection efficiency."
In addition to robotic inspectors, a comprehensive network of monitoring devices is continuously working around the clock to safeguard the cables. These include panoramic and high-definition cameras ensuring full coverage of tunnel equipment, infrared thermometers tracking cable temperatures for any overheating issues, and gas sensors monitoring carbon monoxide, oxygen, and hydrogen sulfide levels for dangerous leaks. If water accumulation reaches preset levels, an automatic drainage system kicks in.
To date, Chongqing has installed 1,190 kilometers of cables with voltages of 110 kV and above. These smart devices have transformed the inspection process, shifting from manual checks to real-time, intelligent monitoring. "The smarter inspections not only improve efficiency but also ensure the safety of the city's electrical arteries," said Wu Yu, director of the Cable Inspection Center at State Grid Chongqing Ultra-High Voltage Company.