Branch CT broken line bus fault removing method and system

According to the method and system for removing the bus fault through the branch CT disconnection, whether the CT disconnection of the bus and the branch where the disconnection is located are judged according to the branch zero-sequence current and the differential current, after the CT disconnection occurs, whether the bus has the fault is recognized according to the composite voltage, the braking current, the branch zero-sequence current and the differential current, and when the bus has the fault, the disconnection branch and the bus coupler on the bus are tripped off in the first time limit; when the broken line branch cannot be confirmed, the bus coupler and the no-current branch are tripped, and the fault bus is tripped off in the second time limit. The internal and external faults of the bus area are classified and selected under the CT disconnection condition, the bus fault clearing time is shortened, and the bus protection reliability is improved. Even if the three-phase disconnection of the branch