Real –time Monitoring of Overhead Transmission Line and Its Risk Assessment

To avoid unnecessary accident and to insure that overhead transmission lines operate safely, on-line monitoring operation state and dynamic security evaluation are necessary. Dynamic Line Rating (DLR) system has been introduced in monitoring the real-time weather and line conditions. The conductor temperature in operation is affected by complex components. This paper analyzed the characteristics of operating line temperature, and found that the line load, tension and wind speed are the main contributors to conductor temperature. The conductor temperature model affected by multiple factors based on multiple regression analyses is set up right after parameter estimations. The experiments did on 110kV lines have been discussed and proved the accuracy of the temperature model. In addition, to maintain transmission line reliability under uncertainty, on-line risk assessment is provided to evaluate thermal overload risk of overhead transmission lines. The main results of experimental studies in field are also presented.