发电厂变压器零序保护跳闸出口方式分析

On the Zero Sequence Protection Tripping Outlet Mode of Transformers in Power Plant

在主变压器零序电流保护的设计和出口方式整定中,应充分考虑特殊主接线方式和实际运行方式下的差异,决不能生搬硬套,简单的依据主变零序保护动作后先切除不接地的变压器,再切除接地变压器的原则显然是不合理的;应对主变零序保护动作结果进行分析,合理选择保护装置的跳闸方式或跳闸点,有效地避免发电厂事故扩大化。

Based on the practical example of Gaobazhou Hydropower Plant,the design and setting of the zero sequence protection for main transformers are discussed.Considering the specific connection mode and the practical operation conditions of the transformers,the ordinary operation principle that cutting off the ungrounded transformers first and then the grounded ones simply according to the zero sequence protection action is inappropriate.Instead,the tripping mode or the tripping point of the protection equipment should be selected carefully based on the analysis of the results of the zero sequence protection action,so that the accident can be effectively controlled.