An accurate current transducer is a key component of any power system instrumentation. To measure currents, power stations and substations conventionally employ inductive type current transformers.
With short circuit capabilities of power system getting larger and the voltage level going higher the conventional current transducers becomes more bulky and costly. It appears that newly emerged MOCT technology provides a solution for many of the problems by the conventional current transformers.
MOCT measures the rotation angle of the plane polarized lights caused by the magnetic field and convert it into a signal of few volts proportional to the magnetic field.
Main advantage of an MOCT is that there is no need to break the conductor to enclose the optical path in the current carrying circuit and there is no electromagnetic interference...