Abstract: Lowfrequency oscillation is one of the most important problems of Hall thrusters. The use of RLC filter unit is one of the most common method to reduce the discharge current lowfrequency oscillations. For highpower Hall thrusters, the problems of high direct current power consumption and serious heat generation exist in RLC filter. This paper proposes and describes a novel filter with coupled inductor. The filter with the coupled inductor structure has obvious notch characteristics through reasonable parameter settings, and has the effect of better suppressing lowfrequency oscillation. The circuit model is simulated, and the attenuation effects of different parameters on the lowfrequency oscillation frequency signal and the influencing factors of notch frequency are obtained. The results show that the filter with coupled inductance structure can effectively reduce the inductance value, thereby reduce the power consumption and heat generation of the filter. In theory, the coupled inductance structure filter with notch characteristics has better suppression characteristics for lowfrequency oscillation. It can effectively reduce the interference of the lowfrequency oscillation of the discharge current to the power supply system, and has significant engineering application value.

Key words: Hall thruster, low frequency oscillations, coupled inductor filter, notch mode