Unmanned airborne photography in the power lines inspection bring the significant reduction in time that is spent to search and identify the fractions in case of emergency shutdown. It also accelerates the control rate compared with ordinary ground means of the power line inspection. Nowadays, Supercam UAV has been actively deployed in the provision of unmanned services to numerous subsidiaries of the Federal Grid Company of Unified Energy System (Rosseti Group). The latter is the biggest operator of Unified National Electricity Grid (UNEG) in Russia. The combined linear distance covered by the Supercam UAVs while exercising the power line inspection for Rosseti subsidiaries has already exceeded 8500 km of electric lines.
Keynote possibilities of the unmanned aviation in the remote sensing of power line and infrastructure inspection consist in the following:
- Assessing general condition of electric line that consist of: sections of power line inter-cross; power lines that lay across public roads, swamp and flood area detection; the plant forestry growing along the line and their classification; the presence of combust debris, constructions, forestry and unauthorized waste disposal in the protected area;
- Assessing power line towers and respective elements in construction (traverses, racks, braces, foundations), bending in the mast construction, fracture of the power line, guy wires, fundaments and concrete quality assessment;
- Aerial inspection of wires, insulators, to examine the external conditions of the objects, overheat, insulator overheats, local overheats, wire overlap areas, etc.;
- Determination of geometric parameters: coordinates of land parcels within the protected and sanitary zones surrounding power lines; accurate length measurement of the intermediate electric wire spans; forestry coordinates and height measurement of trees posing a threat to integrity of lines by stalling or leaning; measurement of the forestry area within a land plot; testing of power line sagging and deflection (the dip test or sag test); coordinates acquisition to locate the intercross-section of wires with different constructions, roads, infrastructure objects and hydrographic object network, dimensions measurement to and from objects;
- Operational processing in the generation of digital elevation model, along with digital terrain model (without forestry, construction objects, machinery, etc.), orthomosaics, digital maps and models of the power line towers;
- Great operational efficiency that provides the vast coverage of area of interest ranging from dozens to hundreds km per day with the application of a single aircraft;
- Cost-reduction when compared with the ordinary ground means of remote inspection.