Abstract:
The negative streamer discharge process is a highly nonlinear dynamic process with complex development. In this paper, a short air gap negative streamer discharge model is established for the 'needle-plate' electrode structure and the 1cm air gap, and the rationality of the model is verified by simulation experiments. The effects of the applied voltage rise time and amplitude on the spatial electric field intensity, the charged particle concentration, the streamer development speed and the discharge current variation characteristics of the negative streamer discharge development process are analyzed. As the negative streamer develops from the ' needle ' electrode to the ' plate ' electrode, the axial electric field intensity and the electron concentration in the discharge region increase briefly and then decrease first and later increase. As the rise time of the applied voltage increases, the electric field intensity and the electron concentration of the streamer head increase nonlinearly. When the rise time of the applied voltage
T=0.01ns increases to
T=2ns, the average streamer velocity decreases by 3.38mm/ns. With the increase of the applied voltage amplitude, the electric field intensity and the electron concentration of the negative streamer head show a nonlinear upward trend. When the applied voltage amplitude increases from
U0= –20kV to
U0= –25kV, the average streamer velocity increases by 2.7mm/ns.