Study On Intelligent Early Warning Technology Based On Transmission Line On-line In-spection System

The transmission lines are the transfer passage of electric power. The accidentsoccurred on the transmission lines would have adverse influence on the safe and stableoperation of the power grid. Hence, the safe and stable operation of transmission lines andrelated equipment is particularly importance. At present, the proposal and implementationof the transmission line on-line inspection system provide powerful safeguard for thereal-time monitoring of transmission lines and related equipment. The operating principleand design scheme of the intelligent early-warning system based on the transmission lineon-line inspection system, as well as the judgment method of the typical failures andabnormity are studied in this paper. Meanwhile, the research, development and test of thetransmission line on-line inspection system are also discussed.According to the types and features of the typical failures and abnormity oftransmission lines and related equipment, the intelligent early-warning system withhierarchical structure is built based on the structure of the transmission line on-lineinspection system.The application of image recognition technology is the key for intelligentearly-warning system to implement the failure judgment of transmission lines. With thevideo image, the algorithm based on the combination of frames subtraction and thebackground subtraction is used in this paper to be the judgment method for the first layer ofthe intelligent early-warning system. Taking the icing of transmission lines for example, theprecise failure type judgment method of transmission lines of the second layer of theintelligent early-warning system is elaborated. With combination of the infrared imagery oftransmission lines and meteorological data, the icing condition of transmission lines can bejudged comprehensively.The insulator arc-over is one of the common failures of transmission lines. The currentdistribution laws of the earth wire under condition of the transmission lines grounded faultvia the tower are studied. Besides, the influences of the fault location, tower impedance andoperating condition on the magnitude and phase angle of the earth wire current are discussed. Based on it, the novel section locating method based on the phase angle of theearth wire current is proposed.The development of the transmission line on-line inspection system is studied in thispaper. The Key technologies, like overall design scheme, configuration of the hardwarestructure and software structure of the tower terminal system and back-end host system, areelaborated systematically. The field test results show that the equipment can meet thedesign requirements, which has achieved the scheduled objectives.