Research On Control Strategy And Simulation Of Electrical Power System Of Small Satellite

Electrical power system(EPS) is a key sub-system of small satellite.It takes on the important task which supplies power for other sub-systems of small satellite and effective loads. The quality of supplying power from the EPS influences the work state of small satellite straightly.In this paper, on the basis of comparing the Direct Energy Transfer(DET) mode with the Peak Power Tracking(PPT) mode, the control strategy of the series-configuration PPT mode which depends on changing the modes of operation is studied. A series-configuration PPT based on PIC single chip microcomputer and the algorithm for maximum power point tracking(MPPT) are designed.Meanwhile, on the basis of energy transferring chart, the allocation of the EPS in the solar array and the Lithium-ion battery pack are calculated, and the general process of calculating the output power of the solar array in the series-configuration PPT are summarized.A co-simulation was implemented between the whole model of the EPS is modeled in VTB software and the power control unit models are designed under Simulink environment,which includes peak power tracker, charge controller and mode change controller and so on.Some results of the maximnum depth-of-discharge(DOD) ,single orbit and several orbits energy balance of the on-orbit small satellite EPS are obtained from the co-simulation.These results are given to verify the rationalities of the allocation calculation ahead and the control strategy of the series-configuration PPT mode,and which is a good guide for optimizing the allocation calculation.