Research And Application Of Magnetic Weakening Optimal Control System For Permanent Magnet Synchronous Motor

Cars not only facilitate people’s production and life,but also consume a lot of petroleum energy,and the air pollution caused by exhaust emissions is also inevitable.With the emergence of electric vehicles,the mechanical and exhaust noise generated by traditional fuel vehicle engines has been improved,carbon dioxide emissions have been further reduced,and part of the kinetic energy of deceleration and braking can be stored for vehicle acceleration and start-up required drive consumption,aimed at energy saving and emission reduction.In addition,the structure of the electric vehicle is relatively simple,the operation is convenient,and the daily maintenance cost is relatively less.As one of the key technologies of electric vehicle,the motor drive control system still has some problems,such as large rotating artery,slow dynamic response and so on.Under the premise that there is still no major breakthrough in the vehicle battery technology,in order to improve the battery life of the electric vehicle,it is particularly important to study how to obtain a safer and reliable motor drive control algorithm.Through the analysis of the development history and current situation of electric vehicles and related technologies in different countries at home and abroad,the advantages and disadvantages of different motors are compared,and the permanent magnet synchronous motor with fast response,high precision,small pulsation and high efficiency is selected as the research object.On the basis of vector control technology,aiming at the problem that the output torque of built-in permanent magnet synchronous motor can not be brought into full play in the field-oriented control mode in which the direct axis current component is zero,the maximum torque control mode of unit current is selected to improve the starting torque of the motor.At the same time,the current feedforward compensation control mode is used to make up for the slow dynamic response of voltage feedback flux weakening control.In view of the defect that the torque ripple and dynamic response performance of the conventional flux weakening speed control system can not be taken into account,a single neuron adaptive PID controller is used to optimize it,which improves the poor adaptive ability of the conventional PID controller and does not have the problem of on-line selftuning controller parameters,and improve the control accuracy and stability of the system.Finally,a set of flux weakening optimal control algorithm of permanent magnet synchronous motor is designed.Through the simulation and comparison with MATLAB/Simulink,the results show that,compared with the traditional flux weakening control algorithm,the magnetic weakening optimal control algorithm can provide larger starting torque and reduce the torque ripple obviously.At the same time,it also further improves the dynamic response ability of the system,which proves its feasibility and effectiveness.Finally,according to the designed algorithm,the hardware and software systems are reasonably planned,and a small test platform is built.