Research On Two-stage Anode Power Supply With Wide Input Voltage Range

Electric propulsion systems have broad application prospects in the aerospace field.In the Hall Electric Propulsion System,the Power Processing Unit（PPU）is an important part of it.The anode power supply is the main power module of the PPU.In mainstream satellite power systems,the PPU is powered by the Power Conditioning Unit（PCU）primary power bus(V_BUS),but V_BUSis easily affected by electric propulsion engines,solar arrays and other facilities,and the output voltage fluctuates in a large range.Therefore,it is of great significance to study the anode power supply with wide input voltage range characteristic.In this dissertation,a high-performance anode power supply is designed using a two-stage power topology.The front stage is a inverse-coupled two-phase interleaved parallel Boost converter,and the latter stage is a fixed-frequency LLC resonant converter,which is designed to meet a wide input voltage range characteristic,and has good anti-disturbance ability and higher efficiency.The main research contents are as follows:The working modes and operating principles of the anode power supply are analyzed,and the parameters are designed.The steady-state analysis of the front-stage inverse-coupled two-phase interleaved parallel Boost converter is obtained,and the equivalent inductance values of the input inductors are obtained according to different working modes.The working modal analysis of the subsequent LLC resonant converter is carried out,and the circuit operating characteristics of each stage in the working modal are sorted out.The parameters of the main power topology are designed to meet the requirements of working indicators.An AC analysis model is carried out on the anode power supply.A small-signal modeling method for inverse-coupled two-phase interleaved parallel Boost converters based on the state-space averaging method is proposed,and the open-loop gains under voltage mode control and peak current mode control are obtained respectively.The small-signal modeling of the subsequent LLC resonant converter is carried out using the fundamental wave analysis method,and the modeling process of the LLC converter is deduced in detail.The control loops of the anode power supply are designed.The modeled transfer functions are verified by SIMPLIS simulation software,and the open loop gains of the system are obtained according to the small signal model of the converter,and the frequency domain responses under different input voltages and loads are analyzed to obtain the worst performance of the system.The corresponding Bode diagrams are analyzed,and the closed-loop networks are designed.Prototype production and simulation and experimental analysis of the anode power supply are carried out.The overall design plan of the anode power supply is proposed,and the design process and related parameters of the key circuits are given.The anode power supply is simulated and analyzed by SIMPLIS simulation software,and the steady-state and transient simulation results are obtained;the prototype is built and tested,and the steady-state and transient experimental results are obtained,which verifies the accuracy of the theoretical analysis of this dissertation and the feasibility of engineering practice.