架空线路冰风荷载风险建模及模糊预测

极端冰灾天气会给电力系统带来巨大的经济损失,应对极端冰灾电力系统缺乏及时预警。基于架空输电线路设计标准Q/GDW 179—2008与IEC 60826—2003,建立了架空线路设计冰风荷载曲线。根据线路荷载–强度的随机特性与干涉理论,建立了线路冰风荷载风险模型,即线路冰风荷载的时间相依可靠性模型,用于计算线路不可靠度与故障率,以反映输电系统群发性故障的风险与短期可靠性的共模故障水平。进一步把线路荷载划分为5个运行状态,给出线路的冰风荷载风险裕度。应用模糊理论对线路的短期冰风荷载风险进行预测,并给出了时间尺度上线路的风险测度,可为系统运行人员提供极端冰灾天气时电力系统的预警信息。

Prediction of subsidence risk by FMEA using artificial neural network and fuzzy inference system

Construction of metro tunnels in dense and crowded urban areas is faced with many risks, such as sub- sidence. The purpose of this paper was the prediction of subsidence risk by failure mode and effect anal- ysis （FMEA） and fuzzy inference system （FIS）. Fuzzy theory will be able to model uncertainties. Fuzzy FMEA provides a tool that can work in a better way with vague concepts and without sufficient informa- tion than conventional FMEA. In this paper, S and D are obtained from fuzzy rules and 0 is obtained from artificial neural network （ANN）. FMEA is performed by developing a fuzzy risk priority number （FRPN）. The FRPN for two stations in Tehran No.4 subway line is 3.1 and 5.5, respectively. To investigate the suit- ability of this approach, the predictions by FMEA have been compared with actual data. The results show that this method can be useful in the prediction of subsidence risk in urban tunnels.