Abstract:In the electromagnetic compatibility test, the analog integrator of electronic current transformer is liable to be disturbed.According to the characteristics of surge and common mode interference of electrical fast transient, this paper proposed the antielectromagnetic interference measures for the analog integrator of electronic current transformer. It optimized the voltage suppression circuit using safety capacitors, piezoresistors and transient suppression diodes, improved the filtering circuit using metal film resistors, high frequency capacitors and differential amplifier with high common mode rejection rate. Meanwhile, the surge suppressing, voltage clamping and high frequency filtering of interference signal were conducted by adopting some measures, such as optimizing the circuit board layout and strengthening the grounding, etc. The experimental results proved that this analog integrator has strong antiinterference capacity.

Keywords:electronic current transformer, analog integrator, electromagnetic compatibility, antiinterference, Rogowski coil, common mode interference, differential mode interference