Precision Transmission-Line Inspections from the Ground and Air Safeguard Reliable Power Supply in Autumn

Recently, along a section of transmission line in Baiyun Subdistrict, Taizhou, Zhejiang Province, Li Haotian and Ding Hao, technicians with the Transmission and Substation Operations and Maintenance Center of State Grid Taizhou Power Supply Company, were using an infrared thermal imaging camera to measure the temperature of tower fittings. They also used binoculars and a drone to inspect the conductors and tower structures for damage or missing components. The two technicians moved along the transmission-line corridor, checking tower by tower. At times they stopped to observe the conductors through binoculars; at other times they piloted the drone in closer to inspect for defects. "This line supplies power to a commercial district and a scenic area, so there is no room for carelessness," Li said.

Since the beginning of autumn, electricity demand in Taizhou's commercial districts, scenic areas, and EV charging stations has been rising steadily. Large day-night temperature swings and frequent strong winds during the season add to the operational challenges. Conductors are susceptible to wind-induced swaying and galloping, while repeated temperature fluctuations can cause fittings to loosen or develop overheating problems, posing challenges to the safe operation of transmission lines. State Grid Taizhou Power Supply Company launched its autumn inspections of key transmission lines ahead of schedule, incorporating them into its seasonal safety inspection campaign. The company conducted comprehensive inspections of areas around commercial districts, scenic areas, construction sites and other areas. Based on the importance of each line and its load characteristics, the company adopted tailored inspection strategies combining ground patrols by personnel with aerial inspections using drones. Infrared thermography and other techniques were used to examine key components, including tower foundations, conductor joints, clamps, and insulators, ensuring no blind spots in hazard detection. Each identified hazard was entered into a tracking register and managed through a closed-loop process: identify, register, rectify, and close out. Ding said that more than 200 transmission towers and nearly 40 kilometers of transmission lines had been inspected, and four defects—including overheated clamps and damaged ground-wire fittings—had been promptly rectified. "These lines supply power to commercial districts, scenic spots, and charging stations. The more we patrol and the more we check, the safer and more reliable everyone's power supply will be this autumn."

Preventing third-party damage to transmission lines is another top priority in these patrols. To address risks such as construction vehicles and machinery coming into contact with power lines, the transmission team focused on seven identified high-risk locations, closely monitored construction activities, and assigned personnel to supervise work sites beneath the lines and stop unsafe operations. Patrol frequency was also increased during the inspection campaign. At the same time, the company proactively contacted villages along the transmission routes and construction project teams, explaining on site the hazards associated with working beneath high-voltage lines and the necessary safety precautions to reduce the risk of third-party damage at its source. In addition, crews cleared trees and branches that encroached on transmission-line corridors and reinforced greenhouses beneath the lines to prevent strong winds from blowing foreign objects onto the lines.

During the autumn inspection campaign, the company will closely monitor weather conditions and changes in electricity demand, strengthen transmission-line monitoring and emergency-duty arrangements, improve emergency response plans for ensuring reliable power supply, and ensure adequate emergency repair crews, materials, and vehicles. These measures will enable the company to respond rapidly and effectively to unexpected incidents. Through refined operations and maintenance, it will safeguard the power grid security and provide a reliable electricity supply for local residents' daily lives and production throughout the autumn.