A fiber optical thermometer for high power transformer monitoring utilizing the thermo-optical phase transition of VO2

Reliable operation of high power transformers (HPT) is an essential condition to maintain stable electric energy supply in the increasingly interconnected energy distribution nets. The electrical environment within HPT´s ultimately prevents use of wired thermometers, as thermo-couples or diodes which rely on electrical bias. Here, we propose a rather simple sensor design approach that comprises the thermo-optical properties of the solid state phase transition in Vanadium oxide, in connection with temperature recordings by means of a fiber optic design.