Quantitative and Qualitative Monitoring System for Switchgear With Full Electrical Isolation Using Fiber-Optic Technology

This paper presents the results of a quantitative and qualitative monitoring system for switchgear with full electrical isolation using fiber-optic technology that aims to help in the automation of substations. The remote sensors were installed near each phase of the switchgear and they are powered only by the optical power provided by one pair of optic fibers connected to a remote optical source. At the same time, part of the optical supply power is used to measure the contact quality by using the optical triangulation method. Two microcameras installed in each remote sensor allow for the observation of the switchgear contact and hinge. All data are transmitted by the optical fibers to a control unit installed in the substation room, and from that, the data are transmitted to the utilities´ operating center using the utilities commercial telecom optical network. We describe the system design, laboratory tests, and the field trial conducted in a 138-kV distribution substation.