An electro-optical sensor system for monitoring synchronous compensators in the electrical distribution network is presented. The fiber-optic sensor system is based on two main technologies: optical bend loss sensors for monitoring the brush wear and, free-space optics to determine the dust accumulation from brush wear. Both techniques are characterized to monitor the parameters by means of simple optical power readings. In order to avoid optical power fluctuations in the fiber optics link from interrogation system to the synchronous compensators, bend-loss insensitive fibers are used. The low-cost interrogation system consists on one laser, optical splitters and 80 photodetectors to independently monitor each one of the synchronous compensators’s brushes. This setup ensures an ease installation and avoid cascaded fault that a serial configuration could originates, thus increasing reliability of the sensor system.
We propose a fiber optic sensor array based on bend loss assessed by optical time domain reflectometry (OTDR). The
sensor mechanism is based on optical fiber bending loss compressed by external pressure. An elastomeric surface is
applied to the sensor in order to communicate external pressure to the fiber coil and also, this make sensor able to deal
with degradation coming from aggressive environments. The sensing system proposed is able to monitor liquid or gas
pressure in different environments, such as water, oil, alcohols, some diluted acids and others, depending only of
elastomeric membrane choice. In order to protect the sensor stage against environmental degradation a plastic packaging
was chosen. Bend loss measurements is taken concerning the number of fiber loops involved in the sensor, pump signal
wavelength and temporal width. This long for the best parameters in the sensor construction. The specific case of the
sensor applied to water percolation monitoring from embankment damns is detailed in this paper; for this application the
sensor array have a number of at least six stages totally independent each other, in such a way that each stage can be
developed to monitor a specific environment. Sensors have shown good performance in field tests, reaching work range
from 0.1 to 0.6 atm with 0.05 atm of precision.