某水泥厂电动机差动保护误动故障录波的分析及处理

Analysis and measurement of fault recorder of maloperation of motor differential protection in a cement plant

针对某水泥厂电动机综保装置投运启动过程中出现的几次差动保护误动情况,依据微机型电动机差动保护和差速断保护的定值计算方法对其进行了计算和分析,找出了造成保护误动的主要原因是原保护整定值计算方法不当。提出了相应解决办法,即重新计算了保护定值,修改了电动机保护装置的判断逻辑,增加了电动机启动对差动保护的短时闭锁。实际运行证明,采取该处理方法后,综保装置未有再出现误动现象,且运行稳定。

Aiming at the maloperation of generator differential protection during the start-up of protection and monitor equipment in a cement plant,this paper calculates and analyzes the fault on the basis of the setting calculation of differential protection and differential instantaneous trip protection for the microprocessor based motor,finds the main reason for protection maloperation which is inappropriate protection setting calculation and proposes relevant measurements which is to recalculate the protection setting value,to modify the judgment logic of motor protection device and to increase short block of differential protection.