The study of the influence of different frequencies on the interrupting characteristics of high voltage SF

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circuit breaker is of great significance for the improvement of the breaking performance of circuit breaker under the condition of 60 Hz. Consequently

we established a two-dimensional magnetohydrodynamic（MHD） arc model

after taking the effects of electromagnetic field

arc radiation and nozzle ablation into consideration

and simulated the arcing process under the same condition with arcing time of 17.36 ms. Furthermore

we analyzed and compared the effects of different frequencies on the distributions of temperature and pressure in the arc extinguishing chamber

the arc voltag

e

and the nozzle ablation. The results show that

at the moment of arc extinction

the axial temperature at 50 Hz case is lower than that at 60 Hz

the maximum axial temperature difference is close to 2 200 K

and the axial pressure is slightly higher than at 60 Hz

this indicates that 50 Hz has a better pressure build-up effect and a gas blow cooling effect at the current-zero point;the total energy input and the nozzle ablation mass of the 50 Hz arc are lower than that of 60 Hz

while in the half wave before the arc extinction

the nozzle ablation mass of the 50 Hz arc is 7.3% higher than that of 60 Hz

which improves the pressure build-up effect under the condition of 50 Hz; the extinction peak voltage at 50 Hz is obviously higher than that at 60 Hz

indicating that the 50 Hz dielectric recovery condition is better than that at 60 Hz; thereafter

the influence of frequency on arc interruption performance of puffer-type SF

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circuit breaker is explained.