The Research Of Square Wave And Sine Wave Drive For BLDC Based On DSP

Brushless DC motor has both advantages of AC motor with simple structure, reliableoperation and DC motor with good speed performance. Brushless DC motor has a wide rangeof applications in the dynamic traction system and servo system.With the advantages of small size,immunity to interference, etc., position sensorlessbrushless DC motor control system developed rapidly in recent years.Because of the hugeadvantage,sensorless control technology will be the main direction of the development ofBLDC motors.Traditional BLDC is drived with square wave,but for non-ideal back-EMFwaveform of the brushless DC motor, the output of the sine wave drive (SPWM control orSVPWM control) method has advantages of low torque ripple and audible noise,reliableoperation.Based on summary and study the principle and current common control technology ofbrushless DC motor,with the MATLAB/SIMULINK simulation models of brushless DCmotor speed regulating system, the simulation experiment was completed according to theprinciple of sensorless closed-loop control and SPWM control.The result of simulation wasmade a comparative analysis.Based on the simulation tests on the platform ofMATLAB/SIMULINK,taking the brushless DC motor as controlled object,by TI companyproduction of motor control special microprocessor TMS320F2812digital signal processor assystems control core,using intelligent power module as inverter switch device,a set ofbrushless DC motor speed regulating system was researched and design. Brushless DC motorspeed regulating system hardware experimental platform is made up of the main circuit,drivecircuit,the Back-EMF zero crossing detection circuit,sampling circuit,debugging systemsusing simulators,DSP development board and accused of motor,it can be used for positionsensorless brushless DC motor closed-loop control experiment and simple SPWM controlexperiments, etc. Base on the hardware experimental platform by using C language toTMS320F2812chip for programming has realized the control method of brushless DC motorsensorless closed-loop control and simple SPWM control.Paper finally shows the experiment results and waveform analysis,verified the hardwareexperimental platform of brushless DC motor speed regulating system and the correspondingsource program is effectual and feasible.