| Transmission line lightning strike is the main reason for the line fault. By installing the line arrester and controllable discharging lightning rod, wire and measures of reducing the tower grounding resistance are effective for lightning protection for transmission lines. View of the 110 kV and 220 kV transmission line of a certain power supply company of lightning protection at present to carry out the problem existing in this power supply company belonging to the 110 kV and220kV transmission line lightning protection research is the key to guarantee the system safe and reliable and stable operation. Therefore, how to reduce transmission line lightning disturbance accident become an important subject of power system safe and stable operation.Firstly, discharge principle in transmission line lightning strike, the concrete process of the lightning discharge and mathematical model on the basis of detailed analysis of the line against overvoltage and detour lightning over-voltage lightning resisting level and lightning trip-out rate calculation method.Secondly, according to the monitoring data of recent years with lightning location system, the suitable parameters are put forward for this area of lightning current amplitude probability distribution and 50 lightning ground lightning density parameters calculated, for this area laid the foundation for the further study of transmission line lightning protection;Thirdly, combining with the characteristics of this area, lightning tripping accidents occurred many times in 2013 of 220 kV Chenshuang transmission line,for example, the line is studied through calculation and analysis causes of lightning trip to detour lightning overvoltage caused by lightning. Based on the type line lightning arrester and lightning protection principle of the controllable discharging lightning rod, respectively installed line lightning arrester and controllable discharging lightning rod on the 220 kV transmission line to improve the performance of lightning protection on the line. After the installation is complete after a thunderstorm season time of observation found that 220 kV transmission line without lightning trip-out fault occurs. Circuit is verified through the instance type lightning arrester can improve and controllable discharging lightning rod in the mountains of transmission line lightning protection performance, effectively reduce the lightning trip-out rate of transmission line.Finally, the 110 kV and 220 kV transmission line belonging to this power supply company lightning protection design and technical reform of practical engineering Suggestions are put forward. According to the scientific,comprehensive, coordinated and sustainable development requirements, line lightning protection design and technical reform should follow the unified planning, adjust measures to local conditions, the principle of safety first,technology economy and overall coordination. New transmission lines should try to avoid lightning strong area, make line lightning resisting level with sufficient margin, reducing line tower side wire protection Angle in order to improve the mountain line to prevent lightning strike ability. On line lightning protection technology reform, butt resistance more than 15? tower, the first tower grounding network renovation, reconstruction cannot meet the requirements of easy one-click line lightning arrester should be installed, and the grounding resistance good easy to install controllable discharging lightning rod section of the tower. |
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