基于站域信息共享的CT饱和识别判据

CT Saturation Recognition Criterion Based on Station Domain Information Sharing

由于励磁支路的存在,电流互感器正常运行时的励磁电流较小,而饱和时,饱和程度越严重,励磁电流越大,二次侧电流会出现畸变,将导致相关保护误判,可能会造成设备的损坏甚至电网的瓦解。为解决这个问题,在比较故障支路与其相连母线的其他各支路电气量联系的基础上,综合利用变电站全站的电气信息,提出一种基于站域信息共享的CT饱和识别新方法。利用PSCAD/EMTDC软件验证所提判据在正常运行及故障伴随CT饱和等不同运行状态下的有效性。

Due to the existence of excitation branch,the excitation current of current transformer is small during normal operation.When the current transformer is saturated,the more serious the saturation is,the greater the excitation current will be,and the secondary side current will be distorted,which will lead to misjudgment of relevant protection,and may cause damage to equipment and even collapse of power grid.In order to solve this problem,on the basis of comparing the relationship between the fault current and the electrical quantities of other branches of its connected bus,and comprehensively using the electrical information of the whole substation,a novel CT saturation identification method based on station information sharing is proposed.PSCAD/EMTDC software is used to verify the effectiveness of the proposed criterion in different operating states such as normal operation and fault accompanied by CT saturation.