继电保护装置恒定失效率估算方法

继电保护装置恒定失效率的估算,是继电保护装置可靠性评估的基础。文中分析了根据现场数据估算恒定失效率时存在的数据问题,讨论了适合现场数据的恒定失效率估算方法,即极大似然估计和最小二乘曲线拟合方法。特别地,推导了考虑数据检修、截尾特性的基于极大似然估计的继电保护装置恒定失效率计算方法和最小二乘拟合方法。最后,基于某区域电网220kV及以上线路保护装置2006年和2007年实际运行数据,结合不同数据类型与对应的失效率估算方法估算该电网保护装置整体失效率。对比结果表明:计算恒定失效率时,需要着重考虑数据截尾影响。进一步,结合不同估算方法的特点,讨论了具有较高适应性的估算方法。

On the Estimation to the Constant Failure Rate of Protection Equipments

The constant failure rate played a fundamental role in reliability analysis for the protection devices. This paper focused on the computation approaches for the constant failure rate with the field data. It first listed 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, it deduced the MLE (point estimation and interval estimation) with the censored data and incomplete data. Finally, the estimation of the constant failure rate for the protection equipment of a power system with the field data was carried out, and the difference of the estimation approaches are compared. The results indicated that it was important to take data censor problem into consideration when we calculated constant failure rate with field data. Further, the adaptability for different methods with different data types were also analyzed.