ABSTRACT
The current interruption process in circuit breakers is quite complex and involves interaction of the electric arc, gas flow, ablation and radiation. It is very important to carry out a thorough analysis of circuit breakers for the safety of energy-consuming devices. In the present study, a numerical analysis of a 145 kV high-voltage circuit breaker was carried out using the commercial code FLUENT. A dynamic mesh model was used for the moving boundaries and mesh deformation. Unsteady state simulations were carried out using unsteady Reynolds-averaged Navier–Stokes equations along with a standard k-e turbulence model and discrete ordinate radiation model. To consider the effects of moving boundaries, valve movement, arc generation and variation in properties of SF6, different user-defined functions were written and incorporated in FLUENT. From the analysis, a temperature of around 2000 K was observed in puffer and self-blast volumes. The maximum pressure and temperature near the arc zone were found to be 31 bar and 5000 K, respectively. The study of path lines showed vortex formation and turbulence resulting in energy dissipation in different parts of the circuit breaker. The computational fluid dynamics results were compared with the results provided by the manufacturer and the literature and were found to be in very good agreement.
