Optimization Of Vector Control Current Distribution For AC Asynchronous Motor

As an important means of transportation,the sales of automobiles have steadily increased,but the exhaust emissions from fuel vehicles have increased air pollution and the greenhouse effect.In order to protect the environment,various countries have vigorously developed new energy vehicles.Pure electric vehicles have little pollution and are one of the major new energy vehicles in China's future development.Two types of motors are mainly used in pure electric vehicles: permanent magnet synchronous motors and asynchronous motors.Asynchronous motors have low cost and high reliability and are widely used in passenger cars.In the field of electric vehicles,achieving high-precision control of motors has been the focus of research.Vector control enables the AC asynchronous motor to achieve independent control of torque and flux linkage through coordinate transformation.If you want to achieve high-performance control,you need to optimize the control strategy to improve control accuracy.This article mainly describes a new control strategy.This paper first discusses the basic principle of vector control of AC asynchronous motor,and obtains the basic equation of the motor according to the principle.At the same time,the constraints of motor control,voltage constraints and current constraints are discussed,which lays a theoretical foundation for the later analysis.Secondly,the traditional negative id weak magnetic method is taken as an example to illustrate the shortcomings of traditional control.According to the improvement,the global MAP control strategy adopted in this paper is derived.Thirdly,the theoretical optimal torque control strategy is discussed.Based on this theory,the basic principles and main control strategies(MTPA control and MTPV control)of the global MAP control strategy are described.According to the control strategy,the global MAP controlled operational region is obtained,and the basic equations and constraint equations of the motor are combined to solve the offline table applied by the global MAP control.At the same time,this article details the production process and control strategy flow of the form.From time to time,it shows the complicated working conditions of the motor,the influence of voltage fluctuation and dynamic operation of the motor on the control strategy.A feedforward compensation is proposed,and the principle and control flow of the compensation are explained in detail.Finally,the MATLAB/SIMULINK module is used to build a global MAP control strategy model and a negative id weak magnetic model,and the torque step response experiments are performed on the two models.The feasibility and effectiveness of the global MAP control strategy are proved by comparing the experimental data with traditional weak magnetic field.