Low-cost optical fiber based temperature sensor for real-time health monitoring of power transformers

Plasmonic and interferometric optical fiber sensors for electrical system monitoring applications

“…Plasmonic-enabled nanocomposite sensory films exhibit unique optical properties which derive from localized surface plasmon resonances and depend upon the (1) size, (2) shape, and (3) composition of plasmonic nanoparticles as well as the refractive index of the matrix phase. In the case of harsh environment sensing applications, Aunanoparticle based sensing layers have been a dominant class of materials explored with applications including both temperature [27]- [29] and chemical sensing [30]. When applied to temperature sensing applications, the underlying sensing mechanisms primarily concerns an electron-phonon interaction dominated change in the absorptance and therefore the transmittance output of the evanescent wave fiber, with secondary modalities of wavelength shifts in the localized surface plasmon resonance peak (LSPR) being a combined result of real index change in the matrix and free carrier density change of the Au nanoparticles due to thermal expansion.…”

“…As far as the primary mechanism is concerned, an increase in temperature leads to an increase in resistivity of Au, which elevates the temperaturedependent electron-phonon collision frequency, modifying the absorption as a function of wavelength. Detailed discussion of the temperature dependence of plasmonic nanocomposite-based fiber sensors can be found in prior literature for both evanescent wave absorption spectroscopy [27], [28], [31] and reflection probe configurations [29].…”

“…Although additional work remains, there has been significant progress towards ruggedizing plasmonic nanocomposite-based fiber sensing probes in recent years. Here we provide an example sensor fabricated in an evanescent wave fiber optic geometry through previously described dip-coating process of sol-gel synthesized Au nanoparticles in silica films to leverage the temperature-dependent absorption mechanisms of matrix-protected nanoparticles (MPN) [27]- [29]. Example microstructure and spectral response of Au LSPR in SiO 2 are shown in Fig.…”

Fiber optic sensor for transformer temperature detection

“…Mudabbir Badar and their team use Au-SiO 2 coating and functionalized optical fiber to achieve transformer internal temperature detection, the sensor temperature detection limit of 30-100°C, able to achieve multi-point detection. 15 This optical fiber temperature sensor applied to power equipment, although able to achieve multi-point detection, but the structure is complex and difficult to prepare. Wei et al 16 used fiber optic grating to achieve quasi-distributed temperature detection, and the sensor is suitable for transformer winding temperature detection.…”

“…Although the sensitivity of the sensor is high, the detection limit is low. Mudabbir Badar and their team use Au‐SiO 2 coating and functionalized optical fiber to achieve transformer internal temperature detection, the sensor temperature detection limit of 30–100°C, able to achieve multi‐point detection 15 . This optical fiber temperature sensor applied to power equipment, although able to achieve multi‐point detection, but the structure is complex and difficult to prepare.…”