同轴介质阻挡放电发生器介质层等效电容和负载特性研究

大气压介质阻挡放电(DBD)可以在常压下产生非平衡等离子体,已经成为热点研究领域.通过脉冲或交变电源激发放电,研究电源输出特性、电源与放电发生器负载间的匹配和外界条件对放电的影响对于理解放电现象和提高放电效率具有重要意义.本文采用Lissajous图形法,分别研究了驱动电压、气流速率等因素影响同轴DBD发生器介质层等效电容及负载幅频特性的规律.结果表明,气流速率和驱动电压等外界条件影响DBD发生器的负载特性:介质层等效电容随气流速率增大而减小,随驱动电压增大而增大;幅频特性曲线均表现出RLC回路谐振现象,谐振频率随气流速率增大而增大,随驱动电压增大而减小.通过对比发现,介质层等效电容随频率的变化曲线与幅频特性曲线具有一致的特征,介质层等效电容是影响电路谐振频率动态变化的主要因素.提出了一种有关介质层等效电容的形成机制.

Dielectric layer equivalent capacitance and loading performance of a coaxial dielectric barrier discharge reactor

Dielectric barrier discharge (DBD) can produce non-equilibrium plasma at atmospheric pressure, and it has become a hot point in recent years. For the DBD excited by pulsed or alternated currents, the effects of the loading performance of power supply, the matching between supply and discharge reactor and the discharge phenomena on its discharge are interesting issues. The studies of these issues are of great importance for understanding the DBD processes and improving the power supply efficiency. In this paper, the Lissajous figures of a DBD reactor with coaxial electrode configuration are measured. The loading performance of the DBD reactor and the dependences of excitation voltage and air flow rate on the dielectric layer equivalent capacitance are studied in atmospheric air. According to the experimental data and circuit modeling analysis, it is proved that the dielectric layer capacitance decreases with the increase of air flow rate, but increases with the increase of excitation voltage. The amplitude-frequency performance of the reactor reveals significant RLC circuit resonance. The resonance frequency of the reactor has the same behavior as its dielectric layer capacitance. Therefore it shows that the dielectric layer capacitance is the main factor for the resonance frequency evolution. A possible mechanism responsible for the dielectric layer capacitance is also presented.
Keywords： dielectric barrier discharge loading performance impedance matching plasma