In view of the problem of mal-operation or refusal operation on adjacent feeder column switch due to arc reignition during the fault isolation period of the power distribution grid

the way of parallel capacitor for the column switch is proposed to void its mal-operation in the protection and assure normal operation of equipment of the power distribution equipment.It is found throughout the analysis of the time and frequency domain of the fault current transient processthat the transient fault current causes the highfrequency electromagnetic interference in the operation of circuit breaker which has a great influence on the on-column switch protection

and that the main factor causing the mal-operation or refusal operation is that the fault transient generates an electrical fast transient pulse group.The influence factor of amplitudefrequency characteristics of the electrical fast transient pulse group is discussed.It is found that the influence of coupling inductance and distributed capacitance between the feeders on it is significant

and increasing the distributed capacitance of the feeders of the distribution network can effectively suppress the influence of electromagnetic interference on the switching protection of the smart column.On the basis of this feature

a high-frequency conduction signal suppression scheme for a switched-parallel capacitor on a smart column is constructed.Finally

the effectiveness of the suppression proposal is verified by the use of ATP-EMTP simulation calculation.