Analysis The Work Frequency Operation And Overvoltage Of 500kv Yafu Transmission Line For Guizhou Power System

Operation over-voltage and power frequency over-voltage are the main reasons that cause the damage of high voltage equipment in power network. They bring with natural operation course or broken-down course. If we do not analysis~ calculate this type of over-voltage earnestly, then take corresponding protection measures, especially for the equipment of 500kV voltage level, because of the larger of grounding current ,its over-voltage level is higher in the early days of building power network, we will not mastery the equipment operation course well, furthermore, maybe cause damaging the equipment and cause economic losing. We know that the over-voltage level relevant with material power network environments closing or opening objects fixing equipment, so for any factual engineer, we must calculate the over-voltage, find out its condition, take protection measures, instruct producing course and scientific test, thus prevent the equipment from over-voltage. This paper set Out from practical engineer, discuss the calculation method of operation over-voltage and power frequency over-voltage in the transmission system. Using EMTP, we analysis theoretically the reason that cause operation over-voltage and power frequency over-voltage in closing or open free long line free transformer ,single-phase grounding trouble, then building their mathematical models, It has been showed that the operation over-voltage~ power frequency over-voltage is lower than the prescriptive value for Yafu line. These results will propose theoretical basis to enhance the operation reliability for 500 kV Yafu transmission line.