Rayleigh-based distributed temperature sensing and Fiber Bragg Grating point temperature sensing with a single optical fiber on high electrical potential of 1 MV

A temperature measurement of a high voltage bushing (HV-Bushing) is presented. An optical fiber with several inscribed Fiber Bragg Gratings (FBGs) was used to measure the temperature at given positions and a Rayleigh-based measurement technique was used to measure the temperature (profile) between the FBGs. The used optical frequencies for the FBG and Rayleigh measurement had to be separated to achieve good results. Voltages of up to 1 MV were applied to the HV-Bushing during the measurement.