基于杆塔的雷击跳闸风险评估

Risk Assessment of Lightning Trip-out Based on Power Transmission Tower

为了提高电网雷击跳闸风险评估的有效性和科学性,实现差异化防雷,文中基于灾害学理论提出了一种基于杆塔的雷击跳闸风险评估方法。选取海拔高度、坡度、坡向、土地利用类型和河网密度,构建电网雷击跳闸孕灾环境敏感性评估模型,绘制了浙江电网雷击跳闸孕灾环境敏感度分布图。利用雷电定位系统数据,将地闪密度和地闪强度作为杆塔雷击灾害致灾因子危险性评估指标。将杆塔的耐雷水平作为承灾体易损性的评估指标。基于灾害学理论,利用层次分析法构建包含孕灾环境、致灾因子和承灾体三方面因素的雷击跳闸风险评估模型,计算了浙江电网每基杆塔的雷击跳闸风险值,为电力部门的线路防雷等级升级改造提供帮助。结果表明:位于浙北地区(湖州、嘉兴、宁波、杭州和绍兴)和台州地区的杆塔雷击跳闸风险最高,位于沿海和海岛的杆塔雷击跳闸风险最低,其他地区的杆塔雷击跳闸风险介于两者之间。

In order to improve the effectiveness and scientificalness of risk assessment of lightning trip-out for power grid and realize the differentiated lightning protection technology,a new method of risk assessment of transmission line lightning trip-out is proposed based on the theory of natural disaster. As hazard-pregnant envir- onment factors of lightning trip-out,the elevation,slope,aspect,land use type and river network density are selected to establish a assessment model of hazard-pregnant environment factors of lightning trip-out. The assess- ment indices of disaster-causing factors included the ground-lightning density and ground-lightning intensity observed by the lightning detection and location system. And the lightning protection level is selected as the ass- essment indices of vulnerability of disaster-bearing body. Based on the theory of natural disaster,the disaster- causing factors ,lightning protection level and hazard-pregnant environment are selected as assessment indices to establish the risk assessment model of lightning trip-out in Zhejiang Power Grid by AHP method. And the risk distribution of lightning trip-out in Zhejiang Power Gird for different return periods are given which could provide technical support for lightning protection level upgrading and reconstruction. The results show that the high risk distribution of lightning trip-out is mainly located in the North of Zhejiang,such as Huzhou,Jiaxing, Ningbo and Shaoxing,and Taizhou. The low risk distribution is mainly located in coastal areas and islands.