| In various kinds of electric propulsion system, Pulsed plasma thruster (PPT) is a new and valuable type of space electromagnetic thruster, which has the characteristics of wide application range, low average electric power, simple structure, convenient control, fast respond, high specific impulse, small thrust, easy integration and so on. It can be widely applied in attitude or orbit control propulsion system of micro-satellites, and is the highlight of electric propulsion research in the world currently.In the present paper, by means of theoretical analysis and ground experimental investigation, the design and performance of PPT research have been systematically carried out. The method of PPT applied in micro-satellites was presented and discussed. The ways of PPT prototype design, performance measurement and improving, were explored. The operation process and mechanisms were studied thoroughly by several experimental means.The feasibility of PPT performing manifold micro-satellites attitude or orbit control propulsion missions was analysed and testified systematically. The research results show that PPT is very suitable for micro-satellites perturbation compensation, east west station keeping, constellation phase adjusting, attitude control and so forth. For different propulsion missions, there exist an ideal velocity increment and a fine specific impulse range which are related to structure parameters of satellites and propulsion performance of PPT.A breech-fed parallel-plate PPT which uses solid Teflon as propellant was designed and manufactured. The application features of different energy storage units and discharge initiation devices were contrasted and analysed. The electrodes, transmission lines, propellant feed assembly and other accessories were ameliorated. The type and design project of power processing unit were demonstrated. The PPT can meet the demands of PPT ground experiment research, and its main performance parameters are similar to those of the overseas PPTs of the same type.The PPT discharge current measure system was designed, and through the measurement of the discharge current and voltage, the discharge identities of PPT were studied, the foundation of using theoretical and experiential formulas to calculate the PPT propulsion performance parameters was established. The method of using pendulum balance to measure PPT micro thrust was improved, and taking into consideration the metage of propellant average pulse ablation mass by using microbalance, some propulsion performace parameters of PPT, such as the impulse bit, specific impulse and thrust efficiency were obtained, and it is found that the measurements were in agreement with the results calculated from the experience formulas. Besides, a model based on capacitors degradation failure used for analyzing the PPT energy storage unit reliability was presented, and this model was applied to the estimation of the PPT life.According to the research of PPT ignition, charge and discharge of energe storage unit, the change of electric field and the magnetic field in PPT discharge region during the PPT working process, some conclusions were drawn. PPT operation reliability is influenced by ignition process. The circuit parameters such as resistance, inductance and capacitance in charge circuit and discharge circuit influence the energy transfer and consumption. The distribution and change of electric field and the magnetic field in PPT discharge region and the vicinity, directly determines the formation and acceleration of PPT plasma and the generation of the thrust. Furthermore, through measuring and analyzing the surface temperature of PPT components during PPT working process, the reason of PPT low efficiency was explained from the perspective of heat consumption, the mechanism of PPT heat loss was explored, and the energy distribution and the efficiency composition were further analysed and calculated.By means of high speed photograph during PPT working process, the process of plasma forming, accelerating and diffusing in PPT discharge region was observed. By means of mass spectrum analysis, the components of PPT plume were studied, and the mechanisms of propellant ablation, ionization, sputtering erosion and deposition contamination were analysed from the perspective of the molecule buildup. Using the time domain and the frequency domain analysis and diagnosis techniques, the electromagnetic interference produced by PPT works was studied, and the ways of electromagnetic compatibility were put forward. |
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