The Research Of Control System Of Brushless DC Motor For Ventilator Based On DSP

The ventilator is an indispensably important instrument for clinical salvage and treatment of acute and chronic respiratory attenuation or respiratory dysfunction caused by various reasons,and has an increasing application in clinic.At present ventilators mainly include several types viz gas controlled pneumatic type,electronically controlled pneumatic type and electronically controlled electric type(electrical type) etc.Among these types,the application range of electrical ventilator becomes increasingly wider,so it will become the development direction of future high performance ventilalor.Compared with foreign countries researchs on electrical venlitalor started later in China and the technology and products are not very mature.The main gaps exist in the driving setup-fan and the driving motor.In this dissertation a new and highly efficient micro-turbine fan which is pioneer among the same kind of products in China is designed as the driving setup and brushless DC motor with characteristics of low electromagnetism interfere and high reliability is chosen as the driving motor.The purpose of this dissertation is to design a low-price,high-performance control system for the brushless DC motor to fully exert the advangtage in performance of the brushless DC motor and the micro-turbine fan.Work done in this dissertation includes:(1) The working principal,of brushless DC motor is analyzed,the main formulas are deduced and its mathematical model is built.According to the system requirement the speed and current double close-loop control scheme is ascertained,and the control technology,strategy,method and chip are introduced;(2)The Matlab/Simulink simulation which aimed at the control system has been executed;the results proved that the control strategy is reasonable;(3)Based on TI's DSP-TMS320F2812 and IR's driving chip-IR2131 and MOSFET-IR2807 the hardware circuit is designed;(4)Based on modularizing thoughts the system software programme is written and debugged;(5) The experiments for motor and micro-turbine fan are processed.Their results proved that the control system designed in this dissertation is feasible and achieves the requirement of the designing target and lay basis for the further practicality.