Design And Research Of An Axial Flood Pump System

Permanent magnet Brushless DC motors (BLDCM) have been applied extensively in industrial environment due to its excellent performance. This thesis presents its more applications in Artificial Hearts (AHR). Based on the current development of AHR home and abroad, this thesis designs and manufactures the drive motor and researches the sensoriess control system, in order to realize flood-pump function and gets the total system much smaller and lighter.Firstly, the author summarizes the development course of an AHR, and introduces general situation of AHR this thesis researches, and discusses the theory causes of BLDCM selection. Then the use of sensoriess control method on the basis of measuring back-EMF zero is proposed, and the details are presented.The integrative pump-motor is designed detailedly. A three-slotted stator motor is adopted in this system and its feasibility verified. This can be seen as an innovation in this field.The BLDCM control system includes hardware and software. They both are designed in detail after motor manufacture. The hardware, made up of power circuit, drive circuit, sample circuit (voltage and current), protection circuit and controller based on TMS320LF2407A DSP, is close and reliable. During the course of software design, chop manner is determined first, and then these flow charts of the main program and several crucial interrupt subprogram are given. According to classical control theory, the current-loop and speed-loop are designed respectively from inner to outer by rule, and also the simulation results of step response by MATLAB are illustrated.Finally, the experimental results indicate the acceptable performance of the motor controlled by the board. We can come to a conclusion that the motor and control system presented and designed in this thesis could meet the requirement of the task.