19-10-2017, 12:27 PM
A precise electric current transducer is a key component of any power system instrumentation. The optical current transformer (OCT) is defined as sensors that directly or indirectly use optical detection methods to measure electrical currents. The OCTs are based on the Faraday effect, the interferometric principle, the Bragg Grating and Micromechanical sensors with optical reading.
Operating principle
The magnetic OCT measures the electric current through the Faraday effect. The effects of Faraday are composed of two principles.
• Polarization of light
Polarization is a property of certain types of waves that describes the orientation of their oscillations.
• The polarization of light is mainly of three types
o Linear polarization: when the x and y components of the electric field vector E are in phase.
o Circular polarization: when the components x and y of the field vector E have the same amplitude and have an elimination of 900.
o elliptic polarization: when the phase and amplitude of the components x and y are different.
It can be understood in the following video: