The Research On Lightning Protection Of Transmission Lines In Luohe

Operation data of Luohe transmission lines during these years shows that, operation accidents of power system happen all the time, which severely influence reliability and safety of grid, having impact on production and life of ordinary people. So it has significant meaning to research on lightning protection of Luohe combined with practice condition of Luohe transmission lines.This thesis bases on wide collection and summarizing of operation condition of Luohe transmission lines, analyzes current lightning protection situation of transmission lines. Choosing three 35kV lines and 4 10kV lines as research objects, analyzes the main reason that caused lightning accidents, based on the field test results of earthing resistance of towers, earthing resistance of arresters, lines and gle phase grounding capacitive current. By the field test data of Zhangcheng 35kV lines, electromagnetic transient numerical calculation model according to practical conditions is established using theory of wave process. Considering multiple factors, calculate on overvoltage produced by 35kV lines when lightning happens, large amount of calculation simulation is done to research on how to improve lightning protection level, especially on economic and reasonable application of line arresters, and method of comprehensive treatment of reducing outage rate. Research illustrates that, installing line arresters on prone-to-be-lightning lines on Zhangcheng 35kV lines can improve lightning prevention level by twice even to four times under various conditions.Research demonstrates that, presently, Luohe transmission lines are not shielding lines for whole lines, earthing resistance is over level, some lines do no erect automatic reclosing, lightning protection for transmission lines is quite lack, system neutral point does not take the mode of resonant earthing, lighting situation is comparatively severe. It is proposed that erect ling arrester on lines prone to be attacked by lightning, reduce earthing resistance of tower, improve lightning protection of transmission equipment, improve lightning tolerant level of transmission lines, adopt the mode that neutral point operation by automatic tracking compensation resonant earthing, in order to improve tolerant of the whole Luohe transmission lines and reduce outage rate caused by lightning.