Research on Influences of Lightning Current Amplitude and Wave-head Time to Overhead Line Lightning Overvoltage

摘要

Lightning over-voltage is the major cause of the transmission line interruption and the main reason that endangers the safety and reliability of transmission line system. This paper modelled a single loop overhead transmission line of 330kV with one ground wire based on ATP-EMTP to search the influences of lightning wave, amplitude and gradient to the overhead transmission when hit by back overrating voltage. Combining the feature of fast wave front over voltage and the analysis of model characteristic and the range of application, transmission line model, tower surge impedance model and tower ground resistance model were established, at the same time the insulator flash model was set up using the user defined module. Based on this model, this article chosen two parameters of lightning amplitude and wave-head time as variable to analyze the over voltage level of the A/B/C wires and terminal transformer. The results showed the influence of two parameters above and the critical condition of insulator flash, further more serving the designing of overhead transmission.