Research of the chaos characteristic of the vacuum circuit breaker with coupled physical field simulation
In this paper, a 72.5kV vacuum arc extinguishment chamber is studied through establishing 3D field domain models based on the structures of 1/2 and 1/3 turn coil longitudinal magnetic field contacts with different numbers of slots, at the same time, 3D static simulation and eddy current field simulation were conducted using the finite element method and physical environment method to analyze the influence of different numbers of slots and coil structure on the distribution of longitudinal magnetic field and lag time. To reflect the coupling effect between electric field, magnetic field and air current field, a vacuum arc magnetic fluid model was established after analyzing the existing vacuum arc models and characteristics of vacuum arc under different breaking conditions. After analyzing the instability of vacuum arc, we obtained a non-linear third order ordinary differential equation for electric arc in vacuum breakers. Through adjusting the parameter values relating to vacuum arc in the equation, it is found that the system exhibits a chaotic behavior.