Fault detection of switchgear based on partial discharge gas analysis

Abstract This study investigates the latent partial discharge phenomena in air-insulated switchgear. By analyzing the mechanisms of partial discharge formation and gas decomposition characteristics, an online monitoring device based on gas detection technology is developed. The research demonstrates that partial discharge in air-insulated switchgear causes decomposition of internal gas components, producing characteristic gases such as CO and NO₂. These products serve as critical indicators for detecting partial discharge. A high-sensitivity NO₂ gas sensor is developed using ZnO semiconductor material with composite modification, and a real-time monitoring system is further designed. This provides an efficient and reliable solution for switchgear condition monitoring and fault diagnosis.