Development of Numerical Computational Model for Revolving Metallic Particles' Behavior in GIS and Its Evaluation

摘要

It is widely accepted that gas-insulated switchgear (GIS) has proven to be reliable, compact and has high availability. However, metallic particles forced to fly and kept in motion in a high electric field can cause partial discharges which lead to a flashover of GIS. For a metallic wire particle less than 3 mm long, its revolving flight and horizontal migration behavior become remarkable. This has been confirmed using a high-speed framing video camera. For the revolving particle, we also found that the viscous drag which acts on it controls its flying behavior predominantly. We have formulated a time motion equation for a revolving metallic particle on the basis of statistical analysis of the time-resolved and digitized motion data obtained by a high-speed framing video camera and taking the drag as one of the major force terms. Numerical solution of the time-motion equation gives the maximum flight height-time curves, incidence, departure velocity, and migration velocity of the revolving particle against the grounded electrode with or without slope. Fairly good agreement has been confirmed between the measured and simulated dynamic behavior of the revolving particles. Other major parameters such as allowable maximum flight height, the climbing or descending speed and distance along the slope of the grounded electrode and the trapping factors of a particle trap have been revealed deductively through the simulation. This enables it to optimize the configuration and the operational performance of the particle trap.