Discharge characteristics of metallic particles on the surface of insulating cylinders in high-voltage tank circuit breaker mechanisms under impulse voltage

This paper examines the insulation risks associated with metallic particles within the mechanism chamber of high-voltage tank circuit breakers. An experimental platform was designed to analyze the discharge characteristics of metallic particles on the surface of horizontally oriented cylindrical insulating tubes subjected to impulse voltage. The results show that both the average amplitude and frequency of particle discharge increase with rising voltage. However, the average discharge amplitude tends to saturate or even decrease due to a rise in low-energy discharge events. Metallic particles positioned closer to the electrode exhibit higher discharge amplitudes and shorter discharge delays. A linear arrangement of particles increases their effective length, promoting discharge progression, while a parallel arrangement increases particle curvature, which suppresses discharge. Under positive polarity voltage, the discharge amplitude of particles near the high-voltage side is greater, and the delay is shorter compared to particles near the low-voltage side under negative polarity voltage.