Research On The DSP Based Permanent Magnet Synchronous Motor System

Permanent Magnet Synchronous Motor (PMSM) with small size, high efficiencyand high control accuracy has been widely used in high-precision industrial areas. Thispaper focuses on the closed-loop controller design in Surface Permanent MagnetSynchronous Motor (SPMSM) system. The problems on initial positioning and dead-timeeffect are discussed. Two circuit boards, one is the CPU board using TMS320F2808, theother is the driving circuit board, are designed and the id0vector control algorithmsare realized.This paper establishes the mathematical model of the SPMSM and analyzes theField Oriented Control strategy and Direct Torque Control strategy. Equations are madeto calculate SVPWM theoretical carrier functions with different k. Simulation models arebuilt to calculate the harmonic frequencies at different sampleing frequencies andmodulation indexs. A simple tuning method of PID parameters is proposed. To improvethe windup phenomenon caused by the inverter and motor, the Anti-Windup controlleresare designed, analyzed and simulated in PMSM system, in particular for variablestructure Anti-Windup controller. Decoupling control algorithm is analyzed andsimulated in PMSM current loop, too. Simulation results show the variable structureAnti-Windup strategy reduces the speed overshoot and the response time effectively, andthe decoupling algorithm eliminates dynamic current response errors. Finally a model isbuilt in Matlab and choosing id0vector control and the closed-loop PID strategywith variable structure Anti-Windup controller as the control strategy of the designedsystem.This paper also discusses the problems on the initial positioning and dead-timeeffect, summarizing the common initial positioning strategy, proposing the system initialpositioning strategies and experimental verification. Some strategies are proposed to dealwith the distortion problems caused by dead-time effect and the simulation results verifythe effectiveness. Finally the major hardware schematics and algorithm flow charts areproposed, the experimental current waveforms are given. The experimental results showthe system is well-designed.