基于模糊专家系统的输电线路分段冰风荷载等效停运率模型  

Piecewise Equivalent Model of Ice Disaster Impact on Outage Rate of Transmission Lines Using Fuzzy Expert System

作　　者：段杰[1] 王秀丽[1] 侯雨伸[1] 

机构地区：[1]西安交通大学电气工程学院,西安710049

出　　处：《电工技术学报》2016年第8期220-228,共9页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金资助项目(51277140)

摘　　要：输电线路通常跨度较大,针对一条输电线路在同一时间不同区段可能处于不同冰冻风险等级的状况,引入串联网络模型,先对线路分段,考虑外界条件对停运率的影响,然后再整合,得到整条线路的等效停运率。考虑到气象预测误差和电力系统运行的不确定性对线路停运率计算的影响,建立基于模糊专家系统的线路非解析可靠性模型,将分段等效模型中停运率与主要外界影响因素之间的确定性关系模糊化,选择合适的模糊集、隶属度函数和模糊规则来弥补预测数据不准确带来的缺陷。以IEEE RBTS系统为例,预先设定线路各段所处的天气状况、地形状况和系统运行状态,求解特定工况下线路条件相依的综合停运率。计算结果表明,分段等效模型能够更加准确、合理地反映天气状况和系统状态的变化对线路综合停运率的影响,为评估线路运行风险和电力系统运行可靠性提供了基础。Transmission lines always cross long distance. As different parts of a transmission line may confront different weather conditions at the same time, a piecewise equivalent model is introduced to calculate the outage rate. The transmission line is divided into segments in series according to their particular external environment and their corresponding outage rates. Then these segments are combined to form an integrated outage rate for the entire transmission line. Taken the uncertainty of weather forecast and system operating status into account, the analytical model between load and outage is converted into a fuzzy one. It contains fuzzy sets, membership functions and fuzzy ＂if-then＂ rules, to effectively solve the problems caused by inaccurate data. The new model is applied to IEEE RBTS system. Assuming that a specified transmission line confronts three types of external load pressure in different parts, the outrage rates of the transmission lines are calculated and compared. With the deterioration of the weather condition and system operating state, the outrage rates of the transmission lines increase. The proposed model provides of the foundation for operational risk assessments of transmission lines and power system reliability.

关 键 词：线路停运率 分段模型 模糊专家系统 风力荷载 冰力荷载 

分 类 号：TM734[电气工程—电力系统及自动化]