Abstract:
In this work an optical fiber current sensor was designed and
implemented using helium-neon laser (with wavelength of 632.8 nm and
power of 1 mW) as light source, single mode fiber based sensing element
and photomultiplier as detector. The optical sensors used for measuring
electrical currents are, in fact, magnetic field sensors based on the
magneto-optic Faraday Effect in optical fiber, and its importance is
coming from the fact that measuring electrical currents in high voltage
substations using conventional current transformers (CT) utilize an iron
core and windings ratio to step down the current measured in the primary
to a more manageable current level for secondary devices such as meters
and relays. This signal may be distorted due to saturation of the magnetic
core or electromagnetic waves interference, and it is usually an issue that
involves a great deal of insulation.
The use of optical technology in this field greatly reduces the need for
insulation considering its intrinsic dielectric characteristics and immune
from electromagnetic interference.
This sensor is presently designed to cover current in the range of (20 A to
450 A). Preliminary experimental results for an optical fiber current
sensor are presented. The sensor gave good results under various
V
electrical current supply values, and responded in a linear fashion to an
electrical curr
applied electric current. The results proved that the optical fiber current
sensors can be used in high voltage substations due to their superior
.accuracy, bandwidth, dynamic range and inherent isolation
