Research And Application Of PMSM Vector Control

The main control methods of automatic door at present are DCPWM，VVVF and BLDC with a high speed motor. It needs additionalreduction gear to realize the door opening and closing action, resulting incomplicated structure, high failure rate and maintenance difficulties.PMSM, featuring in its simple structure, small volume, little weight andhigh efficiency, is replacing DC motor gradually in the fields of servocontrol system. So with DSP as the control chip, it can realize highprecision motor servo control.At first, the paper introduced the development of electric drivetechnology, motion control technology and AC servo control system.Then it discussed the principle of PMSM vector control and direct torquecontrol. The model of PMSM has been analyzed, including the structure,coordinate transformation and the mathematical model. The algorithm ofSVPWM technology is elaborated in detail. There are4common methodsof PMSM vector control such as id=0, max Te/i control, field weakeningand max output power control. Using the simulation software(MATLAB/SIMULINK), the author simulated the SVPWM model, established the PMSM control system based on direct torque control(DTC) and vector control (VC). After comparison of two different controlsystem simulation, VC system (id=0) would be further studiedafterwards.TMS320F2812chip was designed as the control unit of the system.The paper also designed the hardware circuit of control and power board,including main loop, drive circuit, AD conversion，current detection andprotection circuit, HALL/ENCODER detection, SCI，etc. Within thedevelopment environment of CCS, the programs have been described inthe paper, including the functions and algorithms of SVPWM,Clarke/Park transformation, AD sampling, QEP and so on.Finally, the results of the test showed the waveforms of PWM signal,stator current, speed, torque and encoder signal. The performance ofPMSM system has a fast dynamic response under the vector control forid=0. It realized the current loop, speed loop and position loop controlsystem, and is applied to the experimental platform of automatic door inthe laboratory. As a result, the system performed as expected.