摘要
为解决利用时差法识别区外故障后闭锁差动保护期间发生区内故障,导致保护延时动作的问题,结合虚拟制动电流采样点检测CT饱和方法,提出了引入相对磁链积累变化情况及交流量幅值特征作为开放保护的辅助判据,并利用相对磁链累积一周波内的方差来代表变化情况以及最小二乘法拟合得到二次电流的交流幅值,以达到正确识别转换性故障的目的。通过四种工况仿真表明,该法提高了抗区外故障的饱和能力,保证了保护的可靠性和灵敏性。
To solve the delay action of protection when the external faults change to be the internal faults during the block of differential current protection, based on the method of testing current transformer saturation at virtual brake current sampling point, this paper proposed to introduce the characteristic of relative fl ux linkage accumulation and the amplitude of the current as a new criterion to open the protection, using the relative fl ux linkage accumulation variance at one cycle and the real-time least square（RLS） algorithm to obtain the amplitude of secondary current, so as to distinguish the transferring faults accurately. Four kinds of working conditions simulation shows that this method resists external faults saturation more strongly to ensure the reliability and sensibility of protection.
出处
《电工电气》
2015年第10期16-20,28,共6页
Electrotechnics Electric
关键词
电流互感器
虚拟制动
相对磁链积累
差动保护
current transformer
virtual brake
relative fl ux linkage accumulation
differential protection
