Foreign objects hanging on power transmission lines - from kites, plastic films to dust-proof nets and agricultural films - have long been the "invisible killers" of the safe operation of power grids. These seemingly insignificant foreign objects, once entangled with the conductors, are highly likely to cause phase-to-phase short circuits or single-phase grounding faults in a humid environment. The consequences can range from line discharge losses to tripping and even conductor breakage, leading to large-scale power outages.
Traditional obstacle removal often requires power line shutdowns, involving user power outage arrangements and load transfer, which is complex and affects power supply reliability. The laser obstacle removal device can perform live-line operations without power outages, achieving "zero perception" for users and "zero interruption" for line operation, with no impact on the operation of the power grid during the operation process.
During a typical operation of State Grid Wuhan Power Supply, over 10 meters of nylon kite string entangled around three-phase conductors and insulator strings was safely removed in 20 minutes through a segmented cutting method, using an adaptive spot size control system to carbonize layer by layer. The entire process was free of open flames and splashing. According to the on-site supervisor, compared with traditional methods, the laser obstacle removal technology has increased the efficiency of removing floating foreign objects by more than five times.
In the first real operation of the State Grid Yongjing County Power Supply Company, the plastic film wrapped around the 35-kilovolt conductor was quickly melted and detached under the precise laser irradiation, with the entire process taking only about 10 minutes. The power line remained safe and stable throughout. The operators on the spot were impressed, saying, "Previously, dealing with such hazards would take most of the day from applying for power outages to climbing the tower for operations, and there were also risks of falling from heights and electric shock. Now, we can 'hit the target' from the ground, which is both fast and stable."
With the maturation of laser obstacle removal technology, a variety of high-performance products have emerged in the market, allowing for selection based on actual needs. The HIZ-NT-QZY live-line laser obstacle removal device from Guangxi Hai Zhuo covers voltage levels from 10kV to 1000kV, featuring a compact and lightweight design. It is equipped with built-in protection mechanisms such as tilt angle sensing to prevent tipping over, safety distance warning, and automatic light-off upon personnel intrusion. It offers a targeting accuracy of millimeter level, with a 5 to 20 times increase in obstacle removal efficiency, and is capable of remote operation at distances ranging from 30 to 300 meters.
