Optical chemosensors for transformers'oil degradation monitoring:case studies

Optical chemosensors offer a decisive solution to monitor critical parameters in power transformers, as they can operate safely on electrical equipment. Surface Plasmon Resonance (SPR) is widely used as a detection principle for many sensors operating in different fields, such as bio and chemical sensing. Its use with optical fibers makes the remote SPR sensing straightforward and suitable for applications also in presence of high electromagnetic interferences, as in the case of power transformers. Additionally, a low-cost sensing device is achieved when an SPR chemical sensor is implemented in a plastic optical fiber (POF) in which an artificial receptor of chemical agents in different liquid environments is exploited. In this work, we report an overview on the main results about the feasibility of application of a developed SPR-POF sensor for the detection, in oil matrix, of two markers of the paper-oil insulating system degradation in oil-filled transformer.