故障树分析法在大型电力变压器故障研究中的应用

Application of Fault Tree Analysis to Large-scale Power Transformer Faults Study

故障树是表现一个系统各种故障间逻辑关系的有力工具,然而电力变压器的故障复杂,给故障分析工作带来困难。该文采用故障树分析法(FTA)对大型电力变压器的各种故障进行分析,并对变压器各分系统的故障原因进行了统计计算。分析表明,变压器线圈的故障率和故障概率为最大,分接开关的故障率也较高。利用FTA法对大型电力变压器可靠性指标水平优化后,建议将变压器的工作可靠度从0．6提高到0．9、平均无故障率时间从25年提高到30年以上。文中结论可为大型电力变压器的设计、制造和检修提供理论依据。

Fault tree is a powerful tool for depicting the logical relationship between the faults in system. However, for a sophisticated reliability system, like power transformer, fault analysis is hard or infeasible because of the complexities of the equipment configuration and its faults. In this paper large-scale power transformer faults are analysed by the fault tree analysis method(FTA), and statistic on failure causes of transformer's subsystems are finished. The results show that coils' failure rate and probability are biggest, and tap switches' failure rate is also high. Large-scale electric power transformer reliability index is optimized, it is proved that transformer's reliability could be raised from 0.6 to 0.9 , and mean time to failure could be from 25 years to more than 30 years. The conclusion can provide theoretical basis for large-sized transformer design, production and repair.