Distributed optical distance protection using FBG-based voltage and current transducers

We describe a novel approach to distance protection using optical fiber sensors. An optical protection system utilizing two pairs of hybrid fiber-optic voltage and current sensors is presented, allowing for distributed, multiplexed measurement of voltage and current, and hence impedance, at multiple points on a transmission network. Three separate phase-to-earth fault scenarios are tested in order to demonstrate the scheme´s successful operation in laboratory conditions. The deployment of the proposed scheme in electrical power transmission and distribution systems may allow for novel and flexible protection architectures while reducing the complexity of installation and isolation requirements in the high-voltage environment as well as the elimination of the requirement for a dedicated communication media to implement multi-ended schemes. The possibility of hybrid optical/conventional techniques also exists.