2,884 research outputs found
Condition Monitoring of Power Cables
A National Grid funded research project at Southampton has investigated possible methodologies for data acquisition, transmission and processing that will facilitate on-line continuous monitoring of partial discharges in high voltage polymeric cable systems. A method that only uses passive components at the measuring points has been developed and is outlined in this paper. More recent work, funded through the EPSRC Supergen V, UK Energy Infrastructure (AMPerES) grant in collaboration with UK electricity network operators has concentrated on the development of partial discharge data processing techniques that ultimately may allow continuous assessment of transmission asset health to be reliably determined
Bridges Structural Health Monitoring and Deterioration Detection Synthesis of Knowledge and Technology
INE/AUTC 10.0
Comparison study between acoustic and optical sensors for acoustic wave
The partial discharge (PD) phenomenon is very harmful for electrical appliances and its early detection could be a cost effective approach for the industry. Although many techniques are used for PD detection yet no technique has presented widely acceptable solution. Still the subject needs parallel study of the detection techniques. In this experimental, multimode fiber (MMF) was placed in oil tank. The PD induced acoustic emission (AE) inside the insulation oil. PD signal has been captured by using step-index multimode of fiber optic sensor (FOS). The results shows FOS has good sensitivity in the range of applied high voltage 10Â kV
Highly-sensitive measurements with chirped- pulse phasesensitive OTDR
Distributed optical fiber sensing is currently a very predominant research field, which perceives optical fibers as the potential nervous system of the Earth. Optical fibers are understood as continuous densely-packed sensing arrays, able of retrieving physical quantities from the environment of the fiber.
Some of the most prominent distributed sensing implementations nowadays rely on performing interferometric measurements using the Rayleigh backscattered light, resorting to a technique called Phase-sensitive Optical Time-Domain Reflectometry (CP-ÏOTDR). A variant to this technique has been recently proposed in 2016, known as Chirped-Pulse Phase-Sensitive OTDR, which allowed to overcome most of the limitations of traditional ÏOTDR implementations while retaining a simple setup, yielding remarkably high sensitivities.
In this thesis, we aim to optimize the stability and performance of chirped-pulse ÏOTDR systems over long-term measurements, and develop novel paradigm changing applications benefiting from the high sensitivity provided by the technique. We reach a mK-scale long-term stability in ÏOTDR systems, and perform highly sensitive strain, temperature, and refractive index measurements, demonstrating new photonic applications such as distributed bolometry, electro-optical reflectometry, or distributed underwater seismology. We discuss how these applications might be able of increasing the efficiency in the energy field, paving the way towards the development of self-diagnosable grids (smart-grids), and also of revolutionizing next-generation seismological networks, allowing to overcome some of the greatest limitations faced in modern seismology today.Distributed optical fiber sensing is currently a very predominant research field,
which perceives optical fibers as the potential nervous system of the Earth. Optical
fibers are understood as continuous densely-packed sensing arrays, able of retrieving
physical quantities from the environment of the fiber.
Some of the most prominent distributed sensing implementations nowadays rely
on performing interferometric measurements using the Rayleigh backscattered light,
resorting to a technique called Phase-sensitive Optical Time-Domain Reflectometry
(ÏOTDR). A variant to this technique has been recently proposed in 2016, known
as Chirped-Pulse Phase-Sensitive OTDR, which allowed to overcome most of the
limitations of traditional ÏOTDR implementations while retaining a simple setup,
yielding remarkably high sensitivities.
In this thesis, we aim to optimize the stability and performance of chirped-pulse
ÏOTDR systems over long-term measurements, and develop novel paradigm changing
applications benefiting from the high sensitivity provided by the technique. We
reach a mK-scale long-term stability in ÏOTDR systems, and perform highly sensitive
strain, temperature and refractive index measurements, demonstrating new
photonic applications such as distributed bolometry, electro-optical reflectometry,
or distributed underwater seismology. We discuss how these applications might be
able of increasing the efficiency in the energy field, paving the way towards the development
of self-diagnosable grids (smart-grids), and also of revolutionizing nextgeneration
seismological networks, allowing to overcome some of the greatest limitations
faced in modern seismology today.
We finally conclude and summarize the objectives achieved in this thesis, commenting
on the potential of the novel applications shown, and proposing future lines
of research based on the results
Two decades of condition monitoring methods for power devices
Condition monitoring (CM) of power semiconductor devices enhances converter reliability and customer service. Many studies have investigated the semiconductor devices failure modes, the sensor technologies, and the signal processing techniques to optimize the CM. Furthermore, the improvement of power devicesâ CM thanks to the use of the Internet of Things and artificial intelligence technologies is rising in smart grids, transportation electrification, and so on. These technologies will be widespread in the future, where more and more smart techniques and smart sensors will enable a better estimation of the state of the health (SOH) of the devices. Considering the increasing use of power converters, CM is essential as the analysis of the data obtained from multiple sensors enables the prediction of the SOH, which, in turn, enables to properly schedule the maintenance, i.e., accounting for the trade-off between the maintenance cost and the cost and issues due to the device failure. From this perspective, this review paper summarizes past developments and recent advances of the various methods with the aim of describing the current state-of-the-art in CM research
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