Research On Characteristics And Simulation Of Arc In DC Vacuum Circuit Breaker Under Transverse Magnetic Field

High voltage DC(HVDC)transmission is widely concerned with its advantages of non inductive and non synchronization problem.In the HVDC transmission,the vacuum circuit breaker is an important equipment which can shut and open circuit in normal and fault operations.Arcing is inevitable in the circuit breaker’s breaking.In order to study the characteristics of arc in DC vacuum circuit breaker and how the external transverse magnetic field would affect it,the following work is done in this paper:The black box model of DC vacuum arc is studied.The applicable range,advantages and disadvantages of Mayr arc model and Cassie arc model are analyzed.A hybrid arc model combining Mayr and Cassie arc model is proposed through the establishment of related connection functions.The simulation experiments in simulation software showed that the hybrid arc model has high accuracy and can describe arc characteristics accurately in different current ranges.The magneto hydrodynamics(MHD)model of DC vacuum arc are analyzed and summarized in the process of chemical reaction equations and boundary conditions of arc.The simulation model is established in COMSOL Multiphysics software.After The simulation experiments on DC vacuum arc,the characteristics of arc in different stages are summarized.The changes in the arc characteristic parameters under different clearances between open contacts is studied,and suggestions for the design of DC vacuum circuit breaker contact distance are provided.The effect of transverse magnetic field on DC vacuum arc is simulated.The results showed that under the transverse magnetic field,the movement of the DC vacuum arc in the contact surface is performed.It is intended that the transverse magnetic field can be helpful for weakening the burning of the arc.It is proved that the DC vacuum circuit breaker can improve its ability to extinguish the arc by applying a transverse magnetic field,so suggestions for the design of arc extinguishing device in the DC vacuum circuit breaker are provided.