Electrical Characteristics of an Alternating Current Plasma Igniter in Airflow

The electrical characteristics of an alternating current(AC) plasma igniter were investigated for a working gas of air at atmospheric pressure.The discharge voltage and current were measured in air in both breakdown and stable combustion processes,respectively,and the current-zero phenomena,voltage-current(V-I) characteristics were studied for different working gas flow rates.The results indicated that the working gas between anode and cathode could be ionized to generate gas discharge when the voltage reached 8 kV,and the maximum current was33.36 A.When the current came to zero,current-zero phenomena appeared with duration of 2 μs.At the current-zero moment,dynamic resistance between electrodes became extremely high,and the maximum value could reach 445 kΩ,which was the main factor to restrain the current.With increasing working gas flow rates,the gradient of V-I characteristic curves was increased,as was the dynamic resistance.At a constant driven power,the discharge voltage increased.