昭东电站110 kV主变后备保护拒动原因分析

双圈变压器一般配置复合电压闭锁过电流保护。其复合电压闭锁元件的电压一般取自低压侧母线压变。当主变低压侧开关拉开，其所对应的低压母线由其他电源供电时，若主变及其低压侧发生故障，主变复压过流保护会因复压元件不开放而拒动。对双圈变压器后备保护拒动原因作了进一步的分析，同时就三圈变压器是否存在类似问题作了探讨，提出了多种解决方案及措施，初步形成了解决问题的建议，为解决主变后备保护拒动问题提供参考。

Analysis of a maloperation of transformer's backup protection in 110 kV Zhaodong station

Generally,double-wound transformer is equipped with compound voltage lockout overcurrent protection,which voltage is provided by PT on low voltage bus of transformer.When the switch of main transformer's low voltage bus provided by other power supply is turned off,it will cause compound voltage lockout overcurrent protection failure if main transformer and its low voltage bus break down.This paper analyzes the backup protection failure of double-wound transformer.Furthermore,this paper does some researches ...