Optical Sensing Technologies for Gas-Insulated Equipment: Advances and Perspectives

Gas-insulated equipment (GIE) plays a critical role in modern power systems, where reliable and accurate condition monitoring is essential for operational safety. Optical sensing technologies, benefiting from immunity to electromagnetic interference, high sensitivity, and adaptability to harsh environments, offer promising alternatives to traditional electrical sensors. This review presents a comprehensive survey of optical sensing technologies for GIE, including fiber Bragg gratings (FBG), fiber-optic interferometry, distributed acoustic and temperature sensing, gas absorption spectroscopy, and electric-field detection based on the electro-optic (EO) effect. The fundamental principles, implementation schemes, and typical applications of each method are systematically analyzed. Despite the demonstrated advantages, challenges remain in sensor packaging reliability, optical coupling efficiency, and long-term stability. Future research should focus on enhancing system robustness, spatial resolution, and integration with digital twins and intelligent diagnostic frameworks. This work seeks to bridge GIE and optical sensing technologies, facilitating the development and deployment of high-reliability optical sensing systems for the monitoring of next-generation GIE.