Polarimetric Optical High-Voltage Sensor Using Synthetic-Heterodyne Demodulation and Hilbert Transform With Gain Control Feedback

• Autor(a) principal: Galeti, Jose Henrique [UNESP]
• Data de Publicação: 2017
• Outros Autores: Higuti, Ricardo Tokio [UNESP], Kitano, Claudio [UNESP], Connelly, Michael J.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1109/JSTQE.2016.2616647; http://hdl.handle.net/11449/162224
• topic: High-voltage sensor; instrumentation; measurement; interferometry; metrology; phase measurement

Optical voltage sensors are widely used for high-voltage (HV) sensing, but the measurement accuracy is often compromised by a sensitivity drift due to variations in the ambient conditions. Synthetic-heterodyne demodulation is a useful technique for dynamic displacement measurements using interferometric sensors as it can provide a detected signal that is immune to an interferometric drift. In this paper, a new synthetic-heterodyne technique, employing the Hilbert transform and gain control feedback, is applied to a polarimetric-based optical sensor system and used to measure an HV signal. The system comprises an He-Ne laser source, optical phase modulator, and HV sensor located between two polarizers followed by a photodetector and real-time electrical signal acquisition and processing. The use of a control loop results in significant improvements in the stability and accuracy of the detected HV signal. The sensor system was used to measure a 60-Hz HV signal with an amplitude range of 300 V to 7.5 kV. The sensor was also used to successfully measure the total power line harmonic distortion of a highly distorted 4 kV signal. The experimental results show very good agreement with measurements obtained by using the industry standard signal coincidence method.