Magneto-Optical Current Transformer

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Magneto-Optical Current Transformer
K.GOUTHAM (08L31A0238)
Department of Electrical and Electronics
Engineering, VIGNANS INSTITUTE OF INFORMATION
TECHNOLOGY, Duvvada.
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CONTENTS

• CURRENT TRANSFORMER
• MOCT principle ,working ,design
• MOCT BLOCK DIAGRAM
• APPLICATIONS
• ADVANTAGES
• DISADVANTAGES
• CONCLUSION

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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 currents 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

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MOCT
MOCT 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.

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

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FARADAY EFFECT
By considering the property
faraday given two mathematical equations
ANGLEV
(INTEGRAL OF B)-------------(1)
ANGLEnpermeabilityVI
-------------(2)
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• POLARIZER
• MAGNETO-OPTICAL MATERIAL
• ANALYZER (POLARIZATION PRISM)
• PHOTODIODES

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MOCT DESIGN
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BLOCK DIAGRAM OF MOCT
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APPLICATION

• 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.
• Typically, the design approach is to redefine the
  interface point as to input the analog to digital
  conversion function used by each of these
  measurement systems.

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ADVANTAGES

• 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.

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DISADVANTAGES

• 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

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CONCLUSION

• 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 Faradays principle this transducer
  provides an easier and more accurate way of
  current measurement. This MOCT is widely used in
  power systems and substations nowadays.

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THANK YOU