大型水电站接地网特性参数超标处理方法及其应用

Treatment Methods for Over-standard Characteristic Parameters of the Grounding Grid in Large-scale Hydropower Stations and Their Application

随着电网的发展,系统短路容量大幅增加,其原因是大型水电站接地网具有腐蚀速度快,散流性能不易改善,特别是水下地网维护处理不便,经长期运行后地网特性参数超标问题尤为突出。为此,在对大型水电站地网特性参数进行解析的基础上,针对性的提出了降阻、隔离、限压的一体化治理方法和措施,并应用于地网设计、选材、施工及效果评估等各环节,以期减少水电站地网事故的发生,保障地网安全。

With the development of power grids,the short-circuit capacity of the system is increasing significantly.The reason is that the grounding grids of large-scale hydropower stations are usually of high corrosion rate and poor diffusion performance.Especially,the maintenance and treatment of the underwater grounding grid are inconvenient.After long-term operation,the issue of over-standard characteristic parameters of the grounding grids is particularly prominent.Based on the analysis of the characteristic parameters of the grounding grids in large-scale hydropower stations,integrated treatment methods and measures are proposed correspondingly,such as resistance reduction,isolation,and voltage limitation.The practical application of these measures to the design,material selection,construction and performance evaluation of the grounding grids are also introduced,which could reduce the occurrence of grounding grid accidents in hydropower stations and ensure the safety of the grounding grids.