变压器空投导致相邻元件差动保护误动分析及防范措施  

Analysis on Mal-operation for Current Differential Protection Due to Adjacent Transformer Switching-on and Its Countermeasures

作　　者：戚宣威[1] 尹项根[1] 张哲[1] 王奕[2] 张健[2] 

机构地区：[1]华中科技大学,强电磁工程与新技术国家重点实验室,湖北省武汉市430074 [2]广东电网公司电力科学研究院,广东省广州市510800

出　　处：《电力系统自动化》2016年第3期129-134,共6页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(51277084,51177058);中国南方电网有限责任公司科技项目(K-GD2012-324)

摘　　要：现场发生多起变压器空投导致相邻正常运行的发电机、变压器以及线路差动保护误动的事故,严重影响电网的安全稳定运行。结合现场录波数据与数字仿真,考虑励磁涌流、和应涌流以及互感器饱和等影响因素,文中对差动保护误动的原因展开研究,指出励磁涌流导致的互感器饱和是差动保护误动的主要原因。在此基础上提出了投入谐波闭锁判据、改进比率制动特性等防范措施。现场录波数据和仿真试验结果验证了所研究结论的正确性及应对措施的有效性。Cases of unusual mal-operation of differential protection for transformer,generator and transmission line in operation due to adjacent transformer switching-on have seriously threatened the safe and stable operation of the power grid.An investigation is made on the causes of mal-operation by analyzing the main factors,such as magnetizing inrush,sympathetic inrush,and current transformer saturation,including field recorded fault data and simulation results.It is pointed out that the current transformer transient or current transformer local transient saturation induced by the long-lasting aperiodic component from the magnetizing inrush current is the major cause of mal-operation.To solve this problem,the harmonic restraining criterion and the improved ratio restrained characteristic of current differential protection are proposed to avoid this sort of maloperation.The research results are verified by field recorded fault data and simulation results.

关 键 词：和应涌流 励磁涌流 差动保护 电流互感器 局部暂态饱和 

分 类 号：TM773[电气工程—电力系统及自动化]