Research On Architecture And Control Strategy Of HVDC Power Transformation System In Space Power Station

The emergence of the energy crisis has led to the wider application of solar energy,but collecting solar energy from the ground has its limits,at the same time space solar energy is extremely efficient,hence the idea of building photovoltaic power stations in space had been proposed.At present,the research on space solar power station technology mainly focuses on light and large space structure,thin film solar cell and other technologies.The research of high efficiency high voltage conversion and space power structure management in space environment has been neglected,therefore,this dissertation mainly based on the space power station power level,bus voltage,photovoltaic array output voltage,antenna input voltage,voltage fluctuation and other technical indicators,carry out the scheme design of high power,high efficiency and light weight power transformation suitable for space environment.According to the design requirements of the overall architecture of the space solar power station,the dual bus transmission structure is chosen as the topological structure of the space photovoltaic power station.And combine the particularity of space environment,select Ga As arsenide solar cells suitable for space environment,mathematical modeling is carried out.The transport losses in this paper mainly focus on the copper wire losses between the voltage conversion unit and the microwave transmitter,demand for PV side boost and load side step-down,the solution of voltage transformation based on modular series and parallel technology is considered.a combination converter for IPOS is selected as the input topology of a space solar power station.Because of the space radiation environment,conventional diodes cannot be used properly in space,and the voltage stress of the aerospace diode is very small,to reduce the voltage stress of a single converter rectifier tube,the phase-shifting full-bridge converter is selected as the submodule of the input side conversion system.The relative parameters of the phase-shifting full-bridge converter are designed,demand for maximum power output for space photovoltaic systems,an improved disturbance observation method is used to control the IPOS combinator,moreover,in order to realize the input average flow of various sub modules of the IPOS converter,an internal input current loop was added to control it.Build simulation model,the aim of the IPOS combined converter is to track the PV maximum power and average voltage of the input and output sides.The need for step-down transformation is based on the load side,ISOP combined converter is selected as load side topology.To meet the demand of ISOP combined converters,three-loop control algorithm is used to control the ISOP composite converter,and the load side ISOP combined converter input voltage regulator requirements,the input voltage loop is used to replace the output voltage loop in the three-loop control,small signal modeling for ISOP system,the load-side topology is modeled as a uniform voltage loop,and it carries on the compensation design to it,build simulation model,the purpose of ISOP combined converter is realized,which is to input stable voltage and equal voltage and equal current.