针对会切磁场推力器的低频振荡特性,将推力器的工作模式分为高电流模式和低电流模式,在此基础上研究了低频振荡随工作参数和磁场位形的变化特性,并针对推力系统外回路对低频振荡的影响进行了研究。结果表明,在高质量流量下,随着放电电压的增加.会切磁场推力器的工作模式从高电流模式转换为低电流模式。在高电流模式下,放电电流具有高振幅、低频率的特征,羽流比较模糊,并且电流振荡幅值随着放电电压增大呈先增大后降低的趋势,而对应的振荡频率随着放电电压的增大而增大。在低电流模式下,放电电流具有低振幅、高频率的特征,羽流有两条明显的亮线,并且电流振荡幅值和频率均随放电电压的增大而增大。在不同工况下,随着质量流量增大,放电电流振荡幅值和频率均呈现增大的趋势。研究还发现,外回路中的电阻和电感对低频振荡起到一定的抑制作用,而电容对低频振荡的影响并不明显。
The operation mode of the thruster is divided into high current mode and low current mode to study the low frequency oscillation characteristics in a cusped field thruster.The characteristics of low frequency oscillation were studied by changing working parameters and magnetic field configuration.The effects of the outer circuit on the low frequency oscillation were also studied.Results show that the operation mode of the cusped field thruster converted from high current mode into low current mode with the increase of discharge voltage under the condition of high mass flow.In comparison,the discharge current in high current mode has the characteristics of high amplitude and low frequency with vague plume.With the increasing of discharge voltage,the current oscillation amplitude increases and then decreases,while oscillation frequency increases along with the discharge voltage.However,the discharge current in low current nnode has the characteristics of low amplitude and high frequency,and plume has two obvious bright lines.Current oscillation amplitude and frequency increases with the increasing of discharge voltage.With the increasing of mass flow rate,discharge current oscillation amplitude and frequency tend to increase in different working conditions.Meanwhile,the resistance and inductance in the outer circuit can suppress low frequency oscillation,but the effect of capacitance on low frequency oscillation is not obvious.