特高压快速断路器凸起型陷阱与阶梯加压老炼程序协同优化设计OA

The fast-acting circuit breaker(FACB),as a new generation high-voltage switching device in gas-insulated switchgear(GIS),is widely deployed in ultra-high-voltage DC transmission systems.Its increasingly compact structure significantly reduces internal insulation gaps,posing critical challenges to insulation reliability.During operation and testing,residual or generated metallic particles can easily lift and accelerate under high electric fields,becoming a major source of partial discharges or dielectric breakdown.Engineering experience indicates that,during power frequency withstand tests,if particles are not securely trapped in advance,direct voltage application may induce discharge and obscure latent defects.Therefore,it is crucial to develop a coordinated strategy integrating particle traps with voltage conditioning procedures to ensure particle suppression prior to high-voltage application. To address this,a curved-structure protruded particle trap specifically designed for 800 kV FACB is proposed.Simulation of local electric fields and particle trajectories reveals a dual trapping mechanism combining low-field zones and physical obstructions.Without compromising insulation margins,key structural parameters were optimized—trap thickness of 3 mm,circumferential angle of 40°,height of 5 mm,and slot dimensions of 30 mm × 5 mm—with the trap installed near the interrupter gap and enclosure ends.Simulation results confirm this design balances trapping efficiency and structural reliability,making it well-suited for engineering application. Further field analysis revealed a low-gradient zone approximately 10 cm above the ground electrode,serving as a safe particle movement region.Based on this,the particle safety height was defined.Trajectory simulations were then conducted for representative particle types(spherical:0.5～1 mm;linear:0.1～1 mm;flake:0.15～0.3 mm thick),and their corresponding safe trapping voltages were determined.A stepwise voltage conditioning program was proposed and refined into six voltage steps—280 kV,350 kV,420 kV,500 kV,630 kV,and 700 kV—with durations of 1～5 min and a ramp rate of 10 kV/s. Validation experiments were conducted on a full-scale 800 kV FACB platform.High-speed imaging and ultrasonic sensing confirmed that all particles were stably captured within their respective voltage stages,with no re-lifting or discharge events observed.Compared to direct voltage application,the proposed method reduced particle motion signal intensity by up to 38%.These results verify the practical effectiveness and engineering value of the proposed trap structure and stepwise conditioning program,offering theoretical and technical guidance for insulation reliability improvement in FACB and GIS applications.