Based on the phenomenon of protection malfunction caused by electronic current transformer abnormal work during the operation no-load closing of transformer in a 220 kV new-generation intelligent substation

depth analysis the cause of electronic current transformer abnormal work

and gives specific measures which by changing the electronic current transformer and collector grounding or by merging unit software filtering to improve the electronic current transformer anti-interference ability in DCB. Through this measures

the problem of disturbance appeared in the project put into operation is successfully solved.