Study on spark resistance calculation of discharge channel during capacitor short- circuit

According to the law of conservation of energy and the characteristic curve of capacitor short-circuit discharge, this paper studies the relationship between the circuit parameters and the spark resistance and spark current of the discharge channel during spark discharge. Considering the influence of field emission and Thomson discharge, a mathematical model of micro-nano gap discharge is established. And the time relationship between spark resistance and discharge current including voltage, capacitance, pole distance, and other parameters is derived. Based on the programmable micro-nano gap discharge experimental platform, experiments under different voltages and different capacitances were carried out. The experimental data were compared with the theoretical curve derived by partial weighted regression fitting, and it was found that the theoretical resistance current curve fits well with the experimental fitting curve. Through analysis, we can get: Under different voltages and capacitances, the spark resistance shows a trend of rapid decline first and then slowly rise; the change of the external voltage has no obvious effect on the discharge time, but the peak discharge current will increase accordingly; the increase in capacitance significantly increases the peak discharge current, and the discharge time also significantly increases. The research shows the correctness and accuracy of the theoretical analysis and the proposed model. Through this research, we can further research the energy changes in the discharge gap, which is of great significance to the research of intrinsically safe circuits.