China’s power grid construction has gone through rapid development, and its scale has leapt to the first place in the world. At present, six major trans-provincial power grids, namely the six major power grids in South, Northwest, East, Central, North and Northeast China have been built in China, with a total length of transmission lines exceeding 1.15 million kilometers. Transmission lines of 500kV and above have become the main power transmission grid of each grid.
China has a vast territory, relatively complex topography with more hills and fewer plains, and complicated and changeable weather conditions, which brings certain difficulties to the construction of inter-regional power grids and ultra-high voltage transmission line projects. Meanwhile, transmission lines are distributed in wide outdoor area, and most of the line equipment is exposed to operation in the wild environment. The meteorological conditions are complicated and the on-site environment is changeable. After long-term operation of wires, lightning protection wires, insulators, and fittings, due to the long-term effects of various forces, may suffer broken strands, corrosion, overheating, etc. The traditional manual inspection mode is inefficient, and the contradiction between the number of power transmission professionals and the continuous growth of the equipment scale has become increasingly prominent. By 2013, both the State Grid Corporation of China and China Southern Power Grid actively carried out related work on “helicopters, UAV and manual inspection of overhead transmission lines”, vigorously promoted UAV inspection applications, and established UAV inspection management and technology supporting system, which has significantly improved the efficiency of transmission line inspection.
During the “13th Five-Year Plan” period, the scale of national power grid equipment has developed rapidly. In 2018, he total length of overhead transmission lines of 110 (66) kV and above across the country was 1.214 million kilometers, including 992,000 kilometers operated by State Grid and 222,000 kilometers operated by China Southern Power Grid, and it continues to grow at a scale of about 5% every year. With the gradual implementation of the “new infrastructure” strategy and the increasingly mature development of the UAV industry, the potential and blue ocean of electric power inspection UAV will be further released and expanded in the future. The domestic market is expected to exceed 5 billion yuan in 2020.
The traditional manual inspection method consumes a lot of manpower, requiring at least 20 inspectors. An inspector can generally inspect 6-10 towers a day, while the UAV can complete one-day manual inspection within one hour.
The UAV can be equipped with visible light imaging equipment, infrared thermal imagers, laser barrier cleaners and other equipment, so as to accurately collect the three-dimensional information of the transmission line channel space and the information data of each part of the tower body. In addition, refined inspection and analysis of line operating conditions have effectively reduced manual labor intensity and improved operating efficiency.
Many inspection environments are complex, located in dead zones, unmanned areas, etc. With remote control or autonomous route planning, UAVs can make up for the defect that maintenance personnel do not have favorable traffic conditions.
Multi-rotor drones are used with laser obstacle removal equipment to deal with foreign objects on power distribution lines at designated points.
Applying fixed-wing UAVs and visible light camera loads to realize real-time channelized inspections of illegal construction and trees around distribution lines; use multi-rotor drones with visible light/infrared loads to realize the fixed-point fine inspection of small tower pins, insulators, etc.
Applying long-endurance fixed-wing UAVs with high-definition aerial camera and image post-processing system to take aerial photographs around long-distance power distribution lines, so as to realize regular inspections of the surrounding environment.
Distribution line location planning Applying fixed-wing/multi-rotor UAVs with multi-view cameras to conduct high-resolution and accurate mapping of the target area, so as to provide an accurate basis for the planning of power distribution lines.