Numerical Simulation of Intermediate-Frequency Vacuum Arc

With the development of more/all electric aircraft technology, variable frequency (360-800 Hz) power systems have become an important development focus for future aircraft design. Vacuum switches are highly suitable applications in this aviation power supply environment due to their excellent interrupting ability and reliability. In this paper, vacuum arc behaviors at intermediate frequencies were analyzed, and a numerical model of an intermediate-frequency (IF) vacuum arc was established. The plasma parameters and arc voltage characteristics were investigated. The regularities of arc voltage, ion temperature, ion density and plasma pressure during the arcing cycle were obtained, and the influence of the frequency and amplitude of the current on arc voltage characteristics and plasma parameters were analyzed. The correlations among the peak arc voltages and plasma parameters with the amplitude and the frequency of the current were determined. The results showed that the plasma parameters and arc voltages of the IF vacuum arc were obviously affected by the frequency and amplitude of the current at 2.5-7.5 kA. The simulation results were in good agreement with the experimental results, which proved the validity of this IF vacuum arc model.