Study on Arc Chaos for SF6 Circuit Breaker Based on Coupled Physical Field Simulation

Based on the N-S and Maxwell equation, a mathematical model describing the arc behavior in SF₆ circuit breaker (CB) has been deduced. The effect of Lorentz force, turbulent and physical parameters on the characteristic of arc plasma was considered in the model. Using the finite volume method, the distributions of controlling parameters for arc in SF₆ circuit breaker, such as viscosity, electric conductivity, heat diffusion and heat conductivity have been calculated. By linearizing a set of nonlinear differential equation for arc model according to the theory of differential geometry, arc instable property has been analyzed and nonlinear differential equations with constant coefficient for arc in SF₆ CB has been obtained. By adjusting the controlling parameter of arc in SF₆ CB, the variations of amplitude parameters and phase trajectory in the phase space with time have been analyzed. The calculation results show that the nonlinear system for SF₆ CB has significant chaotic behavior.