Control Strategy Research Of Permanent Magnet Linear Synchronous Motor Based On The Maximization Of Efficiency

Permanent magnet linear synchronous motor (PMLSM) servo control system is a nonlinearsystem of multiinput-multioutput, multivariable coupling and time varying. Because of removingthe middle conversion link and driving load directly, PMLSM motor has faster speed and higheraccuracy. But when the load is with the characteristics of nonlinear, time delay, and strongcoupling, the speed performance and thrust response ability of PMLSM motor will decline.Therefore it is particularly important to research the PMLSM motor speed and thrust controlstrategy. With the development of modern industrial and agricultural production, theconsumption of energy resources is rising, so the research aimed at the efficiency optimizationcontrol strategy of permanent magnet linear synchronous motor becomes hot topics. This paperresearches for PMLSM motor control strategy from two aspects: one aspect is of speed andthrust regulation which mainly analysis the two principles of fuzzy PI control and direct thrustcontrol. The other aspect is of efficiency optimization which mainly expounds the controlprinciple of maximum thrust current ratio. The simulation experimental research of the controlstrategy is carried in through Matlab/Simulink.Firstly, this paper introduces the principle of coordinate conversion, achieved voltage andcurrent decoupling of PMLSM. And then based on the vector transformation, a completePMLSM mathematical model, including the voltage balance equation of PMLSM, theelectromagnetic thrust equation and mechanical movement balance equation, is established. Aservo control system of the PMLSM motor is builded up on these above.Secondly, when the PMLSM motor is influenced by nonlinear, complex and changeful load,according to the problems of the greater mover speed and thrust fluctuation, and the poorself-adjustment ability of PMLSM, the fuzzy PI control and direct thrust control of the PMLSMare designed. The former regulates the PMLSM motor speed, and analysis the disturbance androbustness of motor speed and thrust in different load condition. The latter mainly aims at theii PMLSM motor export thrust and magnetic linkage adjustment, which can improve theanti-interference of the PMLSM output thrust. The above two kinds of methods can improverobustness and dynamic and static stability of the PMLSM. In addition, this paper also putsforward a maximum thrust current ratio control (MTPA) method, and comparison of the fuzzy PIcontrol, traditional PID control when id=0, highlighted the advantages of the MTPA control inmotor efficiency optimization.Finally, the article establishes the PMLSM control module simulation model through theMatlab/Simulink platform. Simulation experiment results show that the design of the fuzzy PIcontrol module and direct thrust control module can improve the robustness and dynamic andstatic stability of the PMLSM in complex load state. And the maximum thrust current ratiocontrol has great advantages in the PMLSM efficiency optimization.