Research Of Lightning Back Flashover Performance And Information Processing Technology Of110～220KV Transmission Line

According to incomplete statistics,12times back-flashover outage faults of110-220kV transmission lines had accured in Tangshan power grid from2008to2012. Such frequent faults seriously affect the national economy, and also bring great social pressure on the power grid corporation. Therefore, there is an urgent need for estimating the lightning back-flashover rate of transmission lines.Combining with the actual operating condition of Tangshan power grid, the main research achievements in this paper are shown as follows:(1) Establishes distributed line model and the wave impedance model of typical transmission line tower. In order to process the data effectively, a model library of wave impedance is also established. Meanwhile, grounding impedances of typical grounding devices are simulated by EMTP and we present the corresponding improvement measures of grounding impedance, which provides technical basis and reference for related research and engineering design.(2) Builts a back-flashover outages simulation model of transimission line by using PSCAD software, and considers the influencing of insulator type, tower grounding impendence, insulation level of lines and other factors on back-flashover performance. According to the above research, brings out counter measures to reduce the lightning trip out rate.These conclusions make guiding significance for lightning protection and tower design.(3) Using Google Earth software to obtain the latitude, longitude and altitude information of tower points, and describes the long line geographical features in a two-dimensional visual. This method can help the technical personnel having a comprehensive understanding of geomorphic characteristics.Through the study, we can master the evaluation method of back-flashover rate of110-220kV power transmission line, understand the influence law of various factors on lightning line trip and master modern information management methods. The results of these calculations show scientific significance and applied value in engineering, and then those can provide a reference basis for the lightning protection of transmission lines.