输变电设备中长期规划可靠性预测中，变压器和输电线路的可靠性模型常采用恒定的稳态不可用率，然而由于设备的短期停运概率与预测时间和运行条件相关，这种模型并不适用于设备的短期可靠性预测。该文建立了条件相依的输变电设备短期可靠性模型，该模型由温度相依的老化失效模型、天气相依的偶然失效模型和电流相依的过负荷保护动作模型3部分构成。模型定量考虑了历史及未来的天气状况、环境温度、风速、风向、日照热量、负荷水平、服役时间等条件对变压器和输电线路短期可靠性的影响。算例详细计算不同运行条件下变压器的停运概率，分析不同时期影响变压器停运的关键因素。结果表明模型能够正确反映运行条件的变化，是合理有效的。该模型可应用于变压器和输电线路的运行风险评估和电力系统运行可靠性评估，帮助调度人员在短期运行规划和在线运行中做出合理的决策。

The reliability models used in mid-term or long-term planning reliability evaluation of transformers and transmission lines are usually represented by their constant steady state unavailability values. However, the short-term outage probability of transmission equipment is dependent on prediction time and operating conditions. A condition dependent short-term reliability model of transmission equipment is presented, which is a combination of three segments: temperature dependent aging failure model, weather dependent chance failure model and current dependent overload protection model. Impacts of historical and future operating conditions on equipment outage probability, such as weather condition, ambient temperature, wind velocity, wind direction, solar heat gain, load current, service time etc, were considered in constructing the model. The model was tested under different operating conditions in case studies and its effectiveness was verified. The model can be applied to operational reliability assessment for both transmission equipment and power systems to help operators make decisions.

国家重点基础研究发展计划项目(973项目)(2004CB217908)。