110kV某变电站1#主变保护误动分析及改造方案的研究

Analysis of a 110 kV substation 1# main transformer protection maloperation and research of the reformation programme

110 kV某变电站1#主变故障分量差动保护误动后,通过对1#主变的一次设备和二次回路及保护装置做全面的检验,对继电保护动作的过程和事故录波报告进行详细的分析,确认了主变保护装置故障分量差动保护的设计原理缺陷是造成本次误动的根本原因。1#主变故障分量差动保护的软件升级,软件的逻辑回路增加了故障分量差动保护2周前无差流判据和稳态量低比率制动辅助判据,可以有效防止故障分量差动保护误动作。软件升级后,照新安装电力设备的检验标准对差动保护装置进行全面的检查,检查合格后方可投入运行。

A 110 kV substation 1 # main transformer fault component differential protection had an unwanted operation. After a comprehensive inspection to the 1# main transformer equipment, the secondary circuit and the protection equipment and a detailed analysis of the course of the operation of the relay protection and the accident report, it is confirmed that the defective design principle of the fault component differential protection of the main transformer protection equipment is the fundalmental reason of that unwanted operation. Through upgrading of the software of the 1# main transformer fault component differential protection, the logic circuit of the software is given a criterion of non-differential current beore 2 circyls and an assistant criterion for braking of steady component and low ratio, unwanted operation of the fault component protection can be effectively prevented. After upgrading of the software, the differential protection equipment is to be comprehensively inspected according to the standards for the newly installed electrical equipment. It must pass the inspection before to be put into operation.