Metal Particle Movement and Induced Partial Discharge Under AC Voltages Superimposed Mechanical Vibration in GIS

Under the combined influence of AC voltages and mechanical vibration, metal particles in gas-insulated switchgear (GIS) exhibit complex movement and induce partial discharge (PD), significantly compromising the safe and stable operation of electrical equipment. In this study, a scaled model of a 330 kV GIS was developed, and an experimental platform integrating AC voltage and steady-state mechanical vibration was constructed. Three distinct particle shapes—spherical, flaky, and linear— were selected, encompassing a total of 18 particle types. The initiation-extinction characteristics were analyzed, and the movement behavior of particles throughout the development stage was described. An AE-vibration combined sensor and a PD detector were used to record discharge signals, from which the PD repetition rate, acoustic flight pattern, and maximum apparent PD amplitudes were obtained. Building on force analysis and charging theory, a method for using flight coefficient of to quantitatively evaluate particle motion was proposed, and its validity was strongly supported by experimental results. This work provides a detailed examination of metal particle movement and induced partial discharge under AC voltages superimposed mechanical vibration, offering insights that may aid in defect detection and condition assessment of GIS equipment.