Research on corona discharge detection by fluorescent optical fiber in multi-insulation media atmosphere

This study investigates the performance of a fluorescence-based optical fiber sensor in nitrogen, air, SF6, and 30%SF6/70%N2 across varying gas pressures. Three characteristic parameters-maximum pulse amplitude, pulse count, and total pulse amplitude-were used to evaluate partial discharge (PD) activity. The results show that all media exhibit fast pulse rise times (100–200 ns), while SF6 and its mixture present the longest fall times (up to 7300 ns). In SF6-based gases, pulse count and total amplitude decrease exponentially with pressure and increase consistently with applied voltage. In contrast, maximum amplitude is highly variable and less reliable. This study reveals distinct PD signal behaviors under different media and conditions, and identifies stable, voltage-sensitive indicators suitable for discharge severity assessment. These findings support the application of fiber-optic sensors in complex insulation monitoring scenarios.