Contact Structure Optimization Of Cup-shaped Longitudinal Magnetic Vacuum Interrupter Based On Manual Zero-crossing Interruption

With the rapid development of HVDC transmission systems and the universal application of new energy and information science and technology,the engineering application of HVDC transmission systems is becoming more and more mature.One way to develop high voltage vacuum interrupters is to improve the contact structure.Experts at home and abroad are devoted to the study of new vacuum arc control technology and new contact structure.The research results show that the improvement of the breaking current capability of vacuum switches is closely related to the contact structure.However,the existing AC arc extinguishing unit is not suitable for DC breaking.The arcing chamber contact structure currently designed for AC breaking conditions is directly applied to the DC breaking condition,which may affect the breaking reliability.The design optimization law of cup-shaped axial magnetic vacuum interrupter contacts based on manual zero-crossing is studied.In this paper,the design optimization law of cup-shaped axial magnetic vacuum interrupter contacts based on manual zero-crossing is studied.The motion law of vacuum arc under the action of axial magnetic field is analyzed,and the physical model of vacuum interrupter is built.Based on the mature traditional AC arc extinguishing unit,the reference parameters and optimization range of the cup-shaped axial magnetic vacuum interrupter contact based on manual zero-crossing are established.The simulation environment conditions are determined in combination with the subsequent experiments.The axial magnetic field distribution intensity of the vacuum interrupter in the manual zero-crossing mode is simulated and analyzed when the current peak and current zero-crossing are obtained.The effect of each parameter on the longitudinal magnetic field intensity distribution of the arc gap is obtained.In the three-electrode mode,each of the parameters concerned about are also simulated.The breaking trigger test was carried out on the manufacturing and processing contacts,and the experimental results were compared with the simulation results.The optimization law of the contact design of the cup-shaped axial magnetic vacuum interrupter is summarized.