A Novel Optical Sensing Technology for Monitoring Voltage and Current of Overhead Power Lines

Abstract

We propose herein a novel optical sensing technology using liquid crystal based transducers to measure simultaneously voltage and current from overhead power lines in real time. Doing so, we implemented a proof-of-principle system based on this approach and we demonstrated not only good accuracy, but also small phase shift and adequate bandwidth for power quality and fault monitoring applications. This is supported by experimental results for current, voltage and power monitoring, which include transient measurements and show excellent agreement with commercial reference probes. The system presented in this paper has been developed for single wire earth return (SWER) lines operating at 12.7 kV or 19.1 kV, but can be adapted to work at higher or lower voltages with appropriate modifications. We conclude by discussing the calibration process improvements that would be required for the technology to meet industry standards.