Movement Behavior and Partial Discharge of the Single Metallic Particle in GIS at Operated Voltage

At operated voltage, the movement behavior, partial discharge, and harmfulness of linear particle in different positions of GIS (high-voltage bus, shield ring, and insulator) are still not clear now. In order to study and solve this urgent engineering problem, the discharge signals, ultrasonic signal, and movement locus of linear particles were recorded and observed. The movement behavior, partial discharge characteristics, and harmfulness of metallic particle in different positions are analyzed and compared. The results suggest that: 1) at operated voltage, the movement behavior of linear particle has a great difference in different positions of GIS. The particle jumps with small height under the high-voltage bus, but the jumping frequency is very high and the time series of discharge signal has one-to-one correspondence with that of the ultrasonic signal. When the particle moves to the shielding ring, particle instantly jumps to the high-voltage electrode. At this time, the consistency between the discharge signal and the ultrasonic signal becomes worse. In addition, when the particle touches the insulator, it can attach to the insulator, never move, and become a fixed metallic particle. 2) When the metallic particle freely jumps under the high voltage bus and the shielding ring, the breakdown voltage of the GIS is still very high. However, when the particle attaches to the insulator, the creeping discharge of the particle will make it has serious harmfulness.