Study On The Control And Management Of High Efficient And Autonomous Satellite Power System

The power condition unit(PCU)serves as an important part of the satellite electrical power system.Due to the special working environment of satellites,the PCU should have the characteristics of high power density,low output impedance and good dynamic response.This paper is mainly divided into four parts,which are power management and control system,power architecture,battery discharge and battery charge.Among the four parts,power management and control system is the chief dispatcher,which controls and measures the state of the remaining three parts.All the parts is used to make a PCU with high dynamic response,high power density and good reliability.In power management and control system,the self-management of the power system in orbit has been analyzed,including the analysis and designing principle of battery charge management,controlling method for failure modes.Meanwhile the principle and design of Main Error Amplifier(MEA)based on trans-conductance has been analyzed in this paper.In the aspect of software,modular-design based on internal bus technology has been researched in this paper.This technology adopts the one-master multi-slave communication mode and sets up upper monitor software to make PCU complete charging or discharging operation to lithium-ion battery or handles fault in orbit according to preconcert management strategy.PCU can work in region of shunt regulator by means of setting the output voltage of MEA.However,the topology of shunt regulator is easily affected by the parasitic capacitance of solar array.The operation process of traditional shunt regulator topology has been analyzed.And the influence of parasitic capacitance is summarized,and comparing the three different topologies which can reduce the effect of parasitic capacitance.Giving the choosing principle of the appropriate topology,and finally certifying the correctness of the experiment.By setting the voltage of MEA,PCU can work in region of battery discharge mode.In this mode,the chemical energy,stored in the lithium-ion battery,can be converted to electric energy for the requirement of PCU.Four topologies have been compared with component stress,complexity control and potential improving of efficiency,and finally the HE-boost topology is used as research object.And small signal model is built to emulate HE-boost topology.By setting the output voltage of MEA,PCU can be worked in region of BCR(Battery Charge Regulator).The bus voltage and battery voltage make BCR be buck topology.This paper finally chooses Superbuck for BCR topology after analyzing all working condition.By building small signal model with working principle,Superbuck converter with coupled inductor is chosen as the topology of BCR.And the intelligent charge-management control scheme and the corresponding protection circuit are designed according to the demand,to ensure the stable and reliable of BCR modules.