Disconnect Switch Position Sensor Based on FBG

This work presents a development of an optical monitoring system based on fiber Bragg grating (FBG) for monitoring the state position and temperature of substations high voltage disconnector switches (DS). Since the sensor is made purely of optical and mechanical components, it can be installed at high voltage environments. The sensor is developed to be installed in the contact base of the DS. The transducer is based on a cantilever beam, in which a pair of FBGs is bonded to its opposing sides and a movable mechanism that deflects it. During the closing state, the movable part of DS makes contact with the base and pushes movable mechanism of the sensor, deflecting the beam. Furthermore, FBGs are intrinsically temperature sensitive, measurement of the mechanical-electric contact temperature can be estimated by the wavelength shifts. A software developed in LabVIEW was used for the acquisition and processing of the data coming from the pair do FBGs. The proposed sensor was tested in a laboratory apparatus and the obtained results showed that the developed system is capable to identify three operating states of the DS: open, completely closed and partially closed, states.