Arc Transfer Characteristics in Targeted Current Conditioning for Vacuum Interrupters

This study experimentally validates targeted current conditioning (TCC) for vacuum interrupters through synchronized optical-electrical diagnostics. Experiments employed a demountable vacuum chamber with axial magnetic contacts under high-vacuum conditions. During multiple TCC discharges at controlled parameters, arc dynamics were captured using high-speed imaging with precise synchronization. Key findings demonstrate: Strong spatial correlation between initial breakdown sites and sustained arcing positions after current-holding phases, confirming consistent weak-spot targeting; Progressive redistribution of breakdown locations across the contact surface with successive discharges; Evolution from localized to homogeneous energy deposition, achieving comprehensive surface coverage after sufficient discharge cycles. The TCC methodology demonstrates three critical advantages: precise spatial targeting of insulation weaknesses, controlled energy deposition at identified defect sites, and progressive homogenization of surface processing. These mechanisms collectively enable complete conditioning coverage.