Daveloping Of Load Simulation System For Space Three-phase BLDCM

The space compressor is a key part of the propellant refueling system,which power of operation is provided by a three-phase brushless DC motor and its control system.A large number of experimental tests are carried on in order to verify whether the motor drive system meets the optimal design requirements of the high reliability,high efficiency and long life of the aerospace system.Therefore,the design of three-phase BLDCM load simulator system is of great practical significance.It simulates the compressor's dynamic torques in the actual working environment so as to meet the verification of the motor drive system.Nowadays,with the rapid development of electronic techniques and automatic controlling techniques,more and more load simulators are controlled by electric technology to improve the dynamic performance.The simulator this paper put forward is based on virtual instrument and has good dynamic torque performance,has the characteristics of modularization,intellectuality and high efficiency,and has high research value.Firstly this paper introduces the existing methods of motor load simulation at home and abroad,and lead to the research significance of the simulation method of motor load based on Virtual Instrument Technology.Then,the three-phase BLDCM is taken as the object of study,and the body design,operation principle and mathematical model of the motor are analyzed.And the basic structure,main functions and working principle of the motor drive system are discussed.In this paper,the principle and format of 1553 B bus communication in space system are introduced in detail.Finally,through the overall understanding of the measured object,a method of BLDCM load simulation system is put forward.Secondly,the mechanical design and electrical hardware design of the whole system are expounded.This paper describes the specific functions,design methods and main parameters of each device and module in detail,and eventually integrates it into a complete load platform.Among them,the hardware system of the platform is constructed with a PXI computer,the built-in data acquisition card and 1553 B bus communication card.Thirdly,the software development of the system is designed and researched in detail.The test software is divided into three modules: instrument control,data acquisition and database storage according to the function.Using LabVIEW programmable language,the program block diagram of each function module can be rapidly designed,and it has a user-friendly human-computer interaction interface.The paper uses VISA interface to realize the communication of USB bus,DAQmx Toolkit to complete the data acquisition of analog data,LabVlEW SQL Toolkit to realize the operation of database and describes the detailed design of 1553 B bus communication subroutine.Finally,the function and performance of the system can meet the requirements through the experimental data.The motor load simulation system designed in this paper has high accuracy of data acquisition,stable operation,flexible operation and convenient debugging.It provides convenience for the reliability verification of the BLDCM control system.In addition,the thesis puts forward the deficiency and improvement direction at the end.