Research on Bus Coupler Charging Protection Problem

According to the relay protection rules, 110kV bus and 220kV bus and above, should be installed special bus protection. This paper do a separate research on bus coupler charging protection from the aspects of bus protection principle and logic of action. It was pointed out that the necessity of blocking differential protection in the process of coupling charging and the new problem of blocking differential protection. This paper puts forward improved bus charging protection after research the processing methods of different relay protection manufacturers, and it improves the reliability of bus coupler charging protection