Drone inspections bolster grid reliability in Liangjiang

With its rotors buzzing, a drone equipped with a high-definition camera and infrared temperature sensors lifted off from the Bailin Substation in Liangjiang New Area.

Operated by Li Jibing, a technician from the northern branch of State Grid Chongqing Electric Power Co, the drone performed a 360-degree inspection of insulator strings, metal fittings, and conductor connection points atop a high-voltage tower. 

On Aug 5, Chongqing's power grid load surged to 30.28 million kilowatts - its fourth highest load this summer. For Li and his team, that translates into intensified inspection duties, with a special focus on heavily loaded circuits in factory hubs and densely populated residential zones.

On Li's controller screen, distinct color gradients revealed the thermal profile of the power equipment. Using infrared temperature sensing, the drone scanned for heat anomalies, with color variations indicating potential issues. These real-time thermal readings enable timely adjustments to power line loads, helping prevent overloads and equipment failures.

                                             

The smallest components are captured in sharp detail on the controller screen. [Photo by Wang Jiaxi] 

Infrared scanning is part of a broader inspection process to ensure stable operation. According to Guan Shengyuan, head of the branch's Transmission Digital Control Unit, inspections cover both transmission line corridors and towers. 

Corridor inspections verify that construction activities and foreign objects near transmission lines maintain a safe distance. Meanwhile, inspections of towers focus on identifying potential issues, ensuring the equipment remains intact and operates reliably. 

In the past, inspecting high-voltage towers often required scheduled power outages or technicians to climb the structures in heavily insulated suits. The task could take nearly an hour per tower and relied heavily on visual checks and operator experience.

Drones have transformed the process. With a single battery charge, a drone can fly for over 20 minutes, inspecting more than 10 towers in one go. Equipped with advanced sensors, drones deliver precise diagnostics and clearly highlight potential hazards.

"Before, a technician could cover up to 30 kilometers of transmission lines in a month. Now, with drone support, we can inspect more than 100 km with greater precision," said Li. 

At the branch's command center, large screens display real-time images of drone nest operations and flight progress along inspection routes.

Operators can control drones from the command center. [Photo by Wang Jiaxi]

More than 1,000 drones and 41 drone nests have been deployed to cover the branch's service area. From the command center, operators can remotely dispatch drones to inspect transmission lines in the surrounding areas. Next-generation technologies such as 5G, the Internet of Things, and artificial intelligence are employed to enhance operational efficiency and inspection quality.