| Permanent magnet synchronous motors are used in aerospace,oil drilling,electric vehicles,rail transit and servo systems for important aspects of national economy and people’s livelihood,due to their high safety,fast system response and high stability.However,these areas require higher control accuracy of the motor.The internal electromagnetic relationship of the permanent magnet synchronous motor is very complicated.During the running process of the motor,external factors such as load fluctuation have a great influence on the control precision of the motor.In order to expand the application field of permanent magnet synchronous motor,improving the load resistance of the motor is an urgent problem to be solved in the current motor control field.Therefore,this paper mainly studies the anti-loading properties of permanent magnet synchronous motor.Firstly,the artical discussed the rationality of the design of the magnetic field of the motor used in the experiment.The two-dimensional and three-dimensional magnetic field analysis models of the motor were established.The back electromotive force at no load,the three-phase winding flux linkage curve and the radial magnetic density component were analyzed,and verified the rationality of the magnetic field design of the motor used in the experiment.Secondly,the principle and algorithm implementation of space vector pulse width modulation were described.The paper established the simulation model of the permanent magnet synchronous motor speed control system by Matlab / Simulink software,and the load resistance of the motor under the traditional PI control was analyzed.The Maxwell and Simplorer software were used to analyze the speed control system of the permanent magnet synchronous motor,and the influence of vector control on the performance of the motor was observed.The simulation results show that the internal harmonics of the motor were small after the motor used in the experiment,which basically meets the experimental requirements.Thirdly,the theory of sliding mode variable structure control is studied,and the sliding film control strategy is presented.In order to improve the chattering problem in sliding mode control,a repeated synovial control method is proposed,and the two control methods were compared.The simulation results show that the repeated synovial control has stronger load resistance and system stability than sliding mode control.Finally,the design and test of the permanent magnet synchronous motor speed control system were studied.The software and hardware design of the speed control system were introduced.The load test bench was built.The experimental results of the proposed sliding mode control and repeated synovial control are compared,in order to verify the correctness of the simulation. |
