MAGNETO-OPTICAL CURRENT

TRANSFORMER

CONTENTS CURRENT TRANSFORMER

MOCT – principle ,working ,design

MOCT BLOCK DIAGRAM

APPLICATIONS

ADVANTAGES

DISADVANTAGES

CONCLUSION

CURRENT TRANSFORMER: CT CONSTRUCTION:

Inductive type transformer with core and primary & secondary windings.

CT WORKING PRINCIPAL: Step up transformer (voltage), step down transformers (current).

PURPOSE OF CT It feeds the current coils of indicating ,metering instruments and protective relays. Watch over the current’s in the circuit.

DISADVANTAGES OF CT: The insulation structure has to be designed carefully to avoid

electric field stress, which could eventually cause insulation

breakdown.

Less reliability

MOCTMOCT Measures the electric current by means of FARADAY EFFECT.

FARADAY EFFECT: “Michael Faraday discovered that the orientation of linearly polarized light was rotated under the influence of the magnetic field when the light propagated in a piece of glass, and the rotation angle was proportional to the intensity of the magnetic field. “

Polarization is a property of certain types of waves that describes the orientation of their oscillations.

By considering the property faraday given two mathematical equations

ANGLE=V (INTEGRAL OF B)-------------(1) ANGLE=n*permeability*VI -------------(2)

FARADAY EFFECT

POLARIZER MAGNETO-OPTICAL MATERIAL ANALYZER (POLARIZATION PRISM) PHOTODIODES

MOCT

BLOCK DIAGRAM OF MOCT

The MOCT is designed to operate in a transparent manner with modern electronic meters and digital relays, which have been adopted for a low energy analog signal interface.

APPLICATION

No risk of fires and explosions. No need to use metallic wires to transfer the signal. High immunity to electromagnetic interference. Larger dynamic range. Low voltage outputs which are compatible with the inputs

of digital to analog converters.

ADVANTAGES

Due to Temperature and stress induced linear changes in the sensing material causes error and instability.

The accuracy of MOCT is some what less than the conventional transformer.

Main cause is temperature drift But the disadvantages can be overcome by implementing the

Double closed-loop self-tuning method

DISADVANTAGES

This paper presents a new kind of current transducer known as magneto optical current transducer.

This MOCT eliminates many of the drawbacks of the conventional current transformers.

By applying Faraday’s principle this transducer provides an easier and more accurate way of current measurement. This MOCT is widely used in power systems and substations nowadays.

CONCLUSION

THANK YOU