摘要
为了分析和应涌流导致变压器差动保护误动的原因以及正确认识和应涌流,通过分析某电厂发生的主变差动保护跳闸的事件案例,阐述了变压器和应涌流产生的机理,利用MATLAB仿真分析了和应涌流的特点以及合闸角度、系统电阻、合闸变压器剩磁、合闸变压器中性点接地方式对和应涌流的影响。分析表明:低电压等级系统、变压器与系统线路较长时,较容易产生和应涌流;减小合闸变压器的剩磁可以减小产生的和应涌流;改变变压器合闸角,可以控制和应涌流现象的发生;变压器中性点接地与否对产生和应涌流的影响不大。建议采取措施降低剩磁和装设涌流抑制器,降低励磁涌流。
In order to analyze the causes of transformer differential protection misoperation caused by sympathetic inrush and correctly understand sympathetic inrush,the mechanism of transformer sympathetic inrush is expounded by analyzing an event case of main transformer differential protection tripping in a power plant,and the characteristics of sympathetic inrush and the effects of closing angle,system resistance,residual magnetism of closing transformer and neutral point treatment of closing transformer on sympathetic inrush are analyzed by MATLAB simulation.The analysis shows that:when the low voltage level system,transformer and system lines are long,it is easy to produce sympathetic inrush;Reducing the residual magnetism of the closing transformer can reduce the generated sympathetic inrush;Changing the closing angle of transformer can control the occurrence of sympathetic inrush;Whether the neutral point of transformer is grounded or not has little influence on the generation of sympathetic inrush.It is suggested to take measures to reduce residual magnetism and install inrush suppressor to reduce excitation inrush.
作者
冷国华
LENG Guohua(Centralized Control Center(Hongshui River)of Guangxi Branch Company of China Datang Co.,Ltd.,Nanning,Guangxi,530029)
出处
《红水河》
2020年第5期73-76,共4页
Hongshui River
关键词
变压器
励磁涌流
和应涌流
差动保护
transformer
excitation inrush
sympathetic inrush
differential protection
