Abstract In the case of abnormal bus-coupler current (such as current transformer wired-break, sampled value chain break, etc.) in double bus with subsection connection, if the busbar not adjacent to the bus-coupler fails, the busbar differential protection may mistakenly trip the bus-coupler element. This paper analyzes the causes of the problems. based on the existing large differential protection and small differential protection, proposed increasing the the medium differential protection to select the fault busbar, so as to ensure that the busbar differential protection can correctly select the tripping element and not trip the irrelevant element when the bus-coupler current is abnormal. The correctness of the scheme is verified by real time digital simulation.
Zhu Junhong,Hu Bao,Zhang Xiaobo等. The bus-coupler current abnormal solution of double bus with subsection[J]. Electrical Engineering, 2019, 20(10): 75-79.
2019, Vol. 20 
