During overvoltage test procedure

the overvoltage frequency is quite high.Subject to electric cable mutual inductance’s influence

during high frequency overvoltage signals transmit in the cable

the higher the frequency

the quicker the attenuation.At the same time

the distance between measuring instrument and the measuring point is often far due to safety factor restriction such as the charged distance

etc.Because there is a direct relationship between electric cable’s mutual inductance and the signal frequency

the measured overvoltage value is then lower than normal because of the attenuation.An optical-fiber transmission overvoltage metering equipment not affected by the attenuation was introduced in this paper

offering reference to the accurate overvoltage measurement and the equipment insulation coordination.