Drone X-ray inspection enhances power line reliability

On Oct 25, beneath a transmission tower in Sihong county of Suqian, Jiangsu province, preparation work was underway for a drone X-ray inspection operation.

Wu Peijun, an equipment maintenance specialist, collaborated with an inspection team to conduct final checks.

Meng Dong, the on-site supervisor, carefully verified all parameters. He confirmed the wind speed was normal and that the insulation ropes and decouplers met operational standards. After ensuring all preparatory work was error-free and conditions were suitable, the operation commenced.

An operator uses an anemometer to measure wind speed and check if it meets the take-off conditions for the drone operation. [Photo provided to chinadaily.com.cn]

Following the instruction, three drones of different sizes and functions took off in sequence. The largest drone, capable of carrying 30 kilograms, lifted off first.

It hoisted a specially designed X-ray imaging plate and flew steadily toward the top of the tower. Subsequently, another drone equipped with an X-ray flaw detector and a third observation drone flew precisely to their predetermined positions.

Meng Dong (first from the left) and his colleagues conduct preparatory tests before the drone flaw detection operation. [Photo provided to chinadaily.com.cn]

Meng Dong explained that this X-ray detection technology is primarily used to diagnose the operating status of tension clamps on transmission lines of 35 kilovolts and above.

These clamps are critical components connecting the conductor to the tower's insulator string and hardware fittings. Internal defects, such as broken steel cores or inadequate crimping, are difficult to detect with conventional methods but can directly threaten line safety.

The TUTU-T5 drone equipped with an X-ray flaw detector conducts flaw detection and photography on the phase B strain clamp of Tower No 3 of the 4W63 Line. [Photo/chinadaily.com.cn]

Historically, inspecting for these problems required workers to climb the towers with equipment. That method not only necessitated power outages but also involved complex safety preparations and high demands on operator skill. A single inspection could take approximately two hours, with results unavailable in real-time.

In contrast, the drone-based X-ray technology demonstrated significant advantages. It eliminates the need for complex safety measures and reduces the risks of working at height. The inspection time for a single tower was cut to under 40 minutes, more than doubling operational efficiency.

Furthermore, staff can access the inspection results in real time via a backend computer on site, enabling "live-line" inspection without power interruption. This innovation enhances efficiency while maintaining power supply reliability.

At the operation site, instructions were issued via the monitoring system for fine adjustments. The imaging plate was secured, and the X-ray flaw detector began its work.

Shortly after, an X-ray image appeared on the computer screen. The specialist confirmed that the steel core of the clamp was in normal working condition with satisfactory crimping integrity, concluding a successful "aerial diagnosis".