Abstract:

With the application of intelligent substation and localized protection, the probability of sampling abnormal great number is increasing. This required higher reliability of busbar protection. This paper introduced a new approach to recognize abnormal sampling. By linear interpolation, the virtual busbar protection difference current could be calculated. To compare actual and calculated difference current, fault and abnormal great number could be accurately distinguished. This method was approved by simulation, and is able to effectively eliminate the effect of sampling abnormal great number on busbar protection, and increase busbar protection reliability.

Key words:

busbar differential protection, abnormal great number, virtual difference current, linear interpolation, difference coefficient