摘要
差动速断保护作为比率差动保护的补充,在变压器发生严重区内故障时可以快速切除故障,但CT(电流互感器)饱和可能引起差动速断保护误动。为此,结合一起由于CT饱和导致的差动速断保护误动案例,对保护动作原因、CT饱和原因及电流波形特征进行分析,提出了一种基于采样值差动原理的差动速断保护抗饱和优化措施。仿真测试和波形回放等试验结果表明,优化后的差动速断保护抗饱和性能明显提高,并且速断的动作特性在金属性故障、转换性故障、永久性故障等情况下均不受影响。
The instantaneous differential protection,as a supplement to ratio differential protection,can quickly remove serious faults that occur in the transformer area.However,CT(current transformer)saturation may lead to maloperation of instantaneous differential protection.Therefore,the paper analyzes the reasons of protection action,CT saturation and current waveform characteristics in accordance to an instantaneous differential protection maloperation caused by CT saturation,and proposes an instantaneous differential protection anti-saturation and optimization measure based on sampling value differential principle.The waveform playback and simulation test show that the anti-saturation performance of the optimized instantaneous differential protection is improved,and the action characteristics cannot be affected under metal faults,switching faults and permanent faults.
作者
周浩
石磊
陆兆沿
ZHOU Hao;SHI Lei;LU Zhaoyan(CYG SUNRI Co.,Ltd.,Shenzhen Guangdong 518057,China)
出处
《浙江电力》
2019年第12期57-63,共7页
Zhejiang Electric Power
基金
云南电网有限责任公司科技项目(YNKJXM00000511)
关键词
变压器保护
CT饱和
差动速断
采样值差动
transformer protection
CT saturation
instantaneous differential protection
sampling value differential
