Diagnostics using airborne survey and fault location systems as the means to increase OHTL reliability

Airborne survey application for diagnostics of overhead transmission lines (OHTL) is quite relevant for power utilities of industrialized counties where power network counts thousands or millions km, of which considerable part has reached 30-50 year lifetime and older. Airborne survey based on aerial scanning as a method of OHTL condition monitoring, is efficient instrument of detection of the line elements deviation off regular condition, serves as a convenient facility of network utility inventory. Advantage of aerial scanning is a combination of high survey accuracy with high work productivity. Processing of digital survey data allows to get essential data required for OHTL reliability analysis: precise span lengths, sag and tension values, conductor clearance to ground, crossed and adjacent objects, clearance to vegetation, distance to nearby trees that may damage OHTL if fallen. For analysis of OHTL reliability, existing software packages allow to carry out modeling condition of separate elements and entire line under extreme ice and wind loads, check safety of conductor clearance to ground and crossed lines under condition of significant conductor overheating determined by necessity to ensure transmission under long-term or short-term (but considerable) load increase. Collection, storage, systemizing, practical use of survey data for development and implementing management decisions and rational usage of network resources is reasonable to accomplish with a specialized information system. Information system helps to provide integrate OHTL monitoring data, modules of record and analysis of technical condition of separate components and entire line, 2D and 3D representation of objects with high georeference accuracy. One of negative examples of insufficient OHTL reliability is fault current caused by lightning, conductor or insulator mechanical damage, etc. Duration of OHTL malfunction, timing and success of emergency elimination depends greatly on accuracy of fault location (FL) on line. Advanced FL system allows to locate fault with accuracy of 5 to 150 m. Combined with aerial scanning data and visualizing line section detected by FL system essentially improves efficiency of service technology, emergency recovery of electric network by maintenance crew, and hence increases system reliability of power objects.