Design on the primary side of active optic-electric current transformer based on the Rogowski coil

In this paper, a principle of design of primary side of active optic-electric current transducer is studied and discussed. By improving the integrator circuits, low-frequency disturbance is eliminated and phase compensation is realized, too. As for the problem of the power supply to the primary side, a new design, which combines the advantages of two methods by the aid of CT and PT respectively, is presented. In order to avoid the problem that the device can't work normally when the main current is either too low or too high, a feedback adjusting circuit and a backup circuit is designed. It is proved by experiments that this design is feasible.