基于统计法的变电站雷击故障率计算方法

摘要

雷击故障率是变电站建设的重要指标，现行的雷击故障率计算需要借助于变电站的运行数据以及计算机模拟，计算复杂，误差较大，而且无法对变电站设计的合理性以及防雷布置的可靠性进行评估。基于统计法提出了一种新的计算方法，利用输电线路和杆塔参数计算线路落雷次数和杆塔雷击频次，再结合雷电流幅值概率求得变电站的雷击故障率。以广东省某500 kV HGIS变电站为研究对象，利用EMTP-ATP建立了变电站仿真模型，模拟雷击杆塔塔顶并沿输电线路侵入变电站，确定临界雷电流幅值。根据该地区的雷电流历史数据，拟合得到更接近实测值的雷电流幅值概率，以此计算得到该变电站的雷击故障率。%Lightning failure rate is an important indicator for substation construction. Current calculation methods of insulation failure rate depend on the operation data of the substation and computer simulation,and are complex and have big errors. Thus,the rationality of substation design and the reliability of lightning protection could not be predicted. Based on the statistical method,a new method is proposed. By using the parameters of the transmission lines and towers,the lightning frequency of tower is calculated,then the light-ning failure rate of substation is calculated by using the probability of the amplitude of lightning current. Taking a 500 kV HGIS substa-tion in Guangdong Province as the research object,a simulation model is established based on EMTP-ATP,and the process of light-ning striking the top of the tower and invading the substation along transmission line is simulated to determine the critical lightning cur-rent amplitude. According to the historical data of the area,the probability of the amplitude of the lightning current is obtained by fit-ting the measured values,then the lightning failure rate of the substation is calculated.