The constant failure rate plays a fundamental role in reliability analysis for the protection devices.The paper focuses on the computation approaches for the constant failure rate with the field data.It first lists the evaluation methods,which are the maximum likelihood estimation（MLE） and least square estimation with linear fitting（LSF）,for the constant failure rate according to the natural of the field data.In detail,the MLE（point estimation and interval estimation） with the censored data and incomplete data is deduced.Finally,the estimation of the constant failure rate for the protection equipment of a power system with the field data is carried out,and the difference of the estimation approaches are compared.Results indicate that it is important to take data censor problem into consideration when calculating constant failure rate with field data.Furthermore,the adaptability for different methods with different data types is also analyzed.

针对"8*14"美加大停电"中期报告"所提供的内容,提出了在继电保护及安全自动装置配置、设计、整定等方面存在的问题,并结合京津唐电网现状,提出了相应的预防性措施.

对1997年京津唐电网220kV系统继电保护装置异常停运的各种情况进行了统计,分析了造成保护装置故障的各种原因.针对京津唐电网现存问题,提出了缩短故障处理时间的具体措施.