纳秒脉冲表面滑闪放电的电气和光学特性

为了研究纳秒脉冲表面滑闪放电特性,本文采用一种新型三电极结构的激励器,通过纳秒脉冲叠加负直流的混合激励模式产生表面滑闪放电。实验研究了电压脉冲分量、电压直流分量及两者的差值对纳秒脉冲表面滑闪放电特性的影响。实验结果表明,当脉冲电压幅值固定时,直流电压幅值的改变对脉冲侧电流的影响较小,但对直流源侧电流却影响显著,直流源侧电流随直流电压幅值的增加而增加,发生表面滑闪放电后峰值和速度均增加。直流电压幅值越大,直流源侧电流出现时刻越早。当直流电压幅值固定时,脉冲侧电流和直流源侧电流均随着脉冲电压幅值的增加而增加。实验中存在一个电压阈值(脉冲分量和直流分量电压差值)使纳秒脉冲表面滑闪放电发生,该阈值为22k V。此时发生表面滑闪放电,瞬时功率峰值、单脉冲能量峰值和稳态能量均迅速增加。脉冲直流电压差值相同时,脉冲分量主导脉冲侧电流的大小,直流分量主导直流源侧电流的大小,脉冲分量所占比例的大小对功率和能量损耗的影响较大。此外,利用数码相机拍摄放电图像研究了纳秒脉冲表面滑闪放电的光学特性,放电图像表明,在电极间施加合理的脉冲电压和负直流电压均可产生表面滑闪放电,实现等离子体的拉伸效果,在阻挡介质表面获得大面积的等离子体。

Experimental and Optical Characteristics of Nanosecond-Pulse Surface Sliding Discharge

In this paper,in order to investigate the discharge characteristics of the nanosecond-pulse surface sliding discharge,a new type of three-electrode structure actuator is adopted to generate sliding discharge driven by a negative DC high voltage combined with a nanosecond pulse.The effects of the DC voltage,the pulse voltage and their potential differences on the dischargecharacteristics of nanosecond-pulse sliding discharge are studied.The experimental results show that the amplitude of the DC voltage has slight effect on the current through the pulse voltage electrode,but it significantly affects the current through the DC voltage electrode when the pulse voltage is fixed.Moreover,current through the DC voltage electrode increases with the increasing of DC voltage,while the peak current increases faster when the sliding discharge occurs.Furthermore,the ignition time of current through the DC voltage electrode is earlier at larger amplitude of DC voltage.The currents through the pulse and DC voltage electrodes increase with the amplitude of applied pulse voltage when the DC voltage is fixed.There is a minimal voltage threshold (the voltage difference between the pulse component and DC component) for igniting a nanosecond-pulse sliding discharge.It is found that the sliding discharge occurs when the potential difference is 22kV,and at this time the instantaneous power,consumption energy and the state energy appear significant increasing trends.The current through the pulse voltage electrode is dominated by the pulse component while the current through the DC voltage electrode is dominated by the DC component under the identical potential difference.Power and energy are primarily affected by the proportion of pulse component.In addition,discharge images are taken by a digital camera.The images show that the nanosecond-pulse sliding discharge occurs when applying suitable pulse voltage and negative DC high voltage on the first-electrode and the third-electrode respectively.In addition,the plasma discharge region significantly extends and the large area plasma can be obtained on the surface of the dielectric barrier.