Study Of PMSM Position Control System Based Fuzzy Logic Theory

Motor control system is widely used with the development of motor manufacturing technics, power and electronics technology,computer technology and modern control theory. The PMSM(Permanent Magnet Synchronous Motor) has gradually replaced the leading position of DC machine because of its superior advantage such as high efficiency,low consumption and high torgue and current ratio, and so on. The digital PMSM servo system,with the executing agency of PMSM, operation processing core of digital microchip and modern intelligent control algorithm is now becoming a popular research direction in the industry field.The design in this thesis mainly includes three steps:Firstly, mathematical model of PMSM was set up, carry out the decoupling process strategy on the 2-phase rotating to d-q matching PMSM's mathematical model with the classical vector control technique. And then, the system's vector control principle and implementation method was illustrated. Let id=0,in order to obtain the highest torque with unit current, and establish 3-closed-loop regulation system of PMSM.Secondly,based on the analysis of PMSM mathematical model,a novel fuzzy PI controller was proposed.The system controller switches between fuzzy controller and PI controller,based on different case of system input error and change rate of error,to make the system have the advantage of quick-activity and anti-disturbance of fuzzy controller and the advantage of high accuracy of PI controller. Finally,simulation based on Matlab/Simulink are carried out and the results show that when comparing to the traditional PI control strategy,systems with the proposed controller characterized by performances of good robustness to disturbances varieties,quick response and better stability.The simulation experiment verifies the correctness and practicability of the control strategy proposed in this thesis.Based on the PMSM's mathematical model, this thesis added Fuzzy PI controller into the servo system to control the system with high precision, and the ability of position tracking, the rapidity and stability of the control system are improved.