Research on CT Type On-line Smart Monitoring Device of Surge Arrester

At present,many domestic smart monitoring systems of the surge arresters are required to use a non-contact monitoring method(CT type).Non-electrical connections between the monitoring devices and the surge arresters can be realized with this monitoring method.The influence of the ground potential rise on the monitoring device could be eliminated.An overvoltage could occur in the secondary side of CT when an impulse current with high amplitude flowed through a surge arrester.It caused damage to the monitoring system.The CT structure to withstand the impulse current with high amplitude,the amplifier protection system and the measurement method of the resistive current of surge arrester were discussed in the paper.