Intelligent Trip-out Fault Diagnosis of Overhead Transmission Line

The intelligent diagnosis of transmission line,including identification of nature of failure and accurate positioning of faults on overhead transmission line,is described,in which identification of nature of failure includes identification of failure by lightning and non-lightning,and accurate positioning of fault is based on a positioning method of distributed traveling wave monitoring technology.The method adopts the equivalent velocity of current wave by on-line measurement to reduce the sag,distortion of the first wave,and other errors.Basing on the theory,we developed a transmission line fault intelligent diagnosis system,which was applied to the Guangdong Power Grid.By comparing the substation fault recorder and lightning location system fault diagnosis,we analyzed superiority of the system in terms of the fault cause identification and fault location.The actual operation shows that fault diagnosis system plays an important role in fault interval orientation,accurate positioning,fault point search,fault cause guidance and lightning protection analysis.