智能变电站二次系统失效风险评估方法

针对智能变电站二次系统建立失效风险评估模型，可以在设备失效风险累积到一定程度时及时安排检修，有效防止系统性故障。文中提出利用可靠性分析工程中的威布尔函数作为二次设备建立失效概率模型，基于二次设备的型式试验、日常运行状态样本数据，采用平均秩次法与最小二乘估计计算回归方程展开模型参数估计，可以获得更加贴近现实运行条件的设备失效模型；利用故障树方法建立二次系统失效与单台设备失效之间的关联关系，可以定量地计算二次系统运行风险顶事件概率分布函数，从而为二次系统失效风险预警、状态检修提供辅助决策。最后，通过示例计算分析表明，运用文中提出的行二次设备失效模型可以为系统检修提供精准时间安排参考。

The equipment failure assessment on the secondary system in smart substation

The establishment of failure risk assessment model for the secondary system in smart substation can help us timely arrange maintenance when the failure risk of equipment accumulates to a certain extent, and thus effectively prevent systematic failure. In this paper, we establish the probabilistic failure model through Weibull probability dis-tribution function from a perspective of reliability engineering. According to the type tests and various daily operation statistics of secondary equipment, the regression equation calculated by the average rank method and least square estimation can obtain the model parameter estimation. By doing so, the equipment failure model closer to the real operation condition can be obtained. Moreover, the relationship between the failures of the secondary system and a single equipment is established through the fault tree. Therefore, the risk probability distribution function of top event in secondary system can be calculated quantitatively, which can provide auxiliary decision for risk warning and state overhaul. Finally, it is verified by the numerical results that, our proposed secondary equipment failure model can provide a reference for accurate time arrangement for system maintenance.