Research And Design Of Manned Spacecraft Low Voltage Power Supply System

The manned spaceflight technology is the most impressive section inthe spacecraft science, with the most complicated control technique,fulfilling the most severe requirements for reliability and safety. Itrepresents a nation’s comprehensive power of science and technology.Now China has already sent astronauts into space and possessed thespacewalk and rendezvous&docking technology. Next step, China willdevelop the new generation of manned spacecraft, more advanced, morecomplicated and multi-functional. With the improvement of mannedspace technology and higher power consumption, the fast growing loadpower requirement has already outpaced the current power system. Underthis circumstance, this paper discussed a manned spacecraft low voltagepower supply system design and key technology research.The rated output voltage of main power circuit in spacecraft powersystem is usually defined as bus voltage, which is determined byspacecraft’s requirements and power load pressure. One common way todesign aerospace high-power system is to increase the bus voltage, andmany countries are studying this high-power system. Domestichigh-voltage bus power system studies have also been started, not yetrefined but has already achieved some progress. One consideration is itnot easy to overcome the negative impacts of increased spacecraft busvoltage, that need further improvement in reliability and safety, and fromthe other perspective, considering national space science strategy, forspacecraft high-power system, both high and low voltage power systemhave their own advantages, we must control the key technology oflow-voltage power supply system while studying the high-voltage buspower system. Considering all those facts, the designing of manned spacecraft power supply system in this paper, will continue to use the28V low voltage high power system, which is bearable by human body.This paper innovatively raise the idea of using a three-unit systemdesign, to ensure the system stability and reduce the pressure of singlecharge/discharge power groups. We choose the lithium ion batteries asenergy storage, whose performance is much better but the control isrelatively complex. In this paper, we focused on designing the three-unitsolution for inter-unit facing discharge balance, fault reconstructionstrategies and the use of lithium-ion battery charge and discharge controltechnology. And we designed the whole power system from the systemcontrol topology selection, solar array design, power conditioning unitand other aspects.This paper simulates the system control techniques and circuits,analyze the energy balance of the system and theoretically verify thefeasibility of the system. We complete ground engineering prototypesystem development according to the power system solutions, conductground performance test on the prototype system function that meet therequirements. Finally, we raise comments and suggests for subsequentimprovement.This paper is based on practical engineering application, combiningwith refined design in and abroad. This paper re-designed the mannedspacecraft power system aiming to fulfill the requirement of large loadpower of manned spacecraft. This program made use of the mostadvanced lithium-ion battery, designed and tested the verifying of charge/discharge control technology. In the three-unit power systemdevelopment process, multi-unit are used for the first time inmulti-streaming and network control technology, and multi-unit faultreconstruction techniques are also the first application of spacecraftpower systems domestically. This paper theoretically supported thefulfillment of requirements for complex multi-unit grid control, andcontribute to the development of energy management in low-orbitspacecraft.