Study on Ultrasonic Propagation Characteristics of Partial Discharge in GIS

With the continuous growth of the domestic economy, the demand for electric energy is constantly increasing. Insulated enclosed combination electrical appliances are widely used in substations due to their relatively small footprint and excellent performance. The study of ultrasonic propagation characteristics of partial discharge in gas-insulated switchgear (GIS) is crucial for the ultrasonic detection of partial discharge in GIS. This article uses a finite element model to simulate the propagation characteristics of ultrasound in GIS cavities and subdivides the local discharge sources into two types, i.e., point sound source (particle discharge) and line sound source (along the surface, suspended discharge), and then compares the two. The results show that the total sound pressure of the point source is distributed in a gradient, and the maximum sound pressure is reached in the annular area near the sound source, which gradually decreases towards both ends, showing a nonlinear relationship. The place where the linear sound source has the greatest effect on the cavity is at the waistline of the center point, and the sound pressure at both ends of the linear sound source is the smallest. The research results have practical guiding significance for ultrasonic detection of GIS partial discharge.