Transient information of system disturbances or faults can be obtained by accurately measuring the waveform

frequency and amplitude of transient current. At present

there are many problems in transient current measurement of the current transformers in power systems

such as

easy saturation

narrow band

being difficult for insulation coordination and so on. It is difficult to measure the transient current effectively because of those problems above. Consequently

we designed an integrated non-contact optical current sensor whose core sensor element is built by the rare earth magneto-optic glass. Based on the magnetic field equivalence principle and by taking the combination of a signal generator and power amplifier as the source

the measurement of 0 to 3.5 kA AC/DC of equivalent transmission lines and its frequency characteristics were achieved. In addition

the transient currents such as short circuit current

harmonic current

nonstandard lightning current and standard lightning current were simulated and measured. The results show that the sensor has good frequency characteristics and its effective frequency band covers DC to standard lightning current. The sensing coefficient is 0.012 4±0.000 5

and the response delay is less than 0.4 μs. The magnitude error is less than 4.5%

and the similarities of waveforms are all above 0.996. Therefore

it has the potential to be applied to practical engineerings.