Research On Fault Location Of UHV Transmission Lines

Voltage level of 500kV and above EHV line is the backbone network transmission system, an important role is self-evident. Currently, the EHV transmission lines have been the main grid, the transmission power has played an important supporting role. With intensive UHV AC and DC put into operation to ensure the reliability of transmission lines has become an important research topic.EHV transmission line has its unique characteristics, namely the length of the transmission line is relatively large, usually in the tens of kilometers, some even up to hundreds of kilometers, or even thousands of kilometers, complex field environment, resulting affect the normal operation of the line factors more, so the probability of failure will be relatively large. Second, the transmission line failure is substantially instantaneous failure, the cause of failure of more than 90% flashover, this failure was not obvious, and since the transmission line more than 30 meters from the ground, to find the point of failure brought great inconvenience. Third, a large load EHV transmission lines to minimize outage time, for the protection of network security, maintaining social stability plays a positive role in promoting. Based on the above three points, the need for accurate fault location becomes more urgent.On consulting a large number of documents related to the topic, based on the existing algorithms and ranging all the traveling wave impedance ranging Arithmetic detailed analysis. The current fault location have a more in-depth thinking, various types of fault location method for a full range of comparison, for the next step to carry out research for EHV transmission line fault location provides a solid theoretical foundation. The comprehensive study on the basis of the results presented a complete set of fault information system applicable to the location program. Ranging programs to the existing hardware based on the conditions, including the two-terminal impedance ranging algorithm, but also single-ended impedance location algorithm to double-synchronization algorithm-based, single-location algorithm for the main side of communication failure auxiliary use. At the same time, extracting the workplace author EHV transmission line fault information for the actual test, from a practical point of giving the scene an objective evaluation. Finally, the research directions of transmission line fault were discussed.