7th International Conference on Electric Power Equipment– Switching Technology (ICEPE 2024)

The breaking performance of a high-voltage circuit breaker is determined by the combination of the interrupter, which extinguish an arc plasma, and the operating mechanism, which control movable part of the interrupter. To enhance the breaking performance of circuit breakers, it is essential to consider continuous operations such as Close-Open and Open-Close-Open sequences in specific duty calculations. A system simulation method that numerically solves internal phenomena using simplified governing equations for each component in high-voltage circuit breakers offers computational cost advantages over computational fluid dynamics (CFD) analysis. Integrating system simulation models for both the interrupter and the operating mechanism enables comprehensive analysis of the circuit breaker's performance.

The accuracy of system simulation model was validated by comparing it with CFD analysis results. We utilized a simplified damper model for the operating mechanism and valve modeling in the interrupter to enhance convergence and accuracy in predicting the travel curve and its effect. Analysis of the pressure in the thermal chamber during operations such as Close-Open and Open-Close-Open, ranging from low breaking currents such as BTF T10 to high breaking currents such as SLF L90, resulted in an error margin within 5% compared to CFD simulations.