Research On PMSM Position Sensorless Control Technology For Vehicles

With the intensification of global energy and environmental pollution problems,people's travel vehicles are also constantly updating in the direction of energy conservation and environmental protection,and electric vehicles have received extensive attention.Permanent magnet synchronous motor(PMSM)can meet the requirements of fast start-stop and variable speed of electric vehicles because of its high efficiency and strong load capacity.The vector control method is generally used to control the PMSM.It is necessary to detect the position and rotation speed of the motor rotor.The traditional detection method is to install mechanical position sensor,it not only enlarges the volume and weight of the motor,but also limits its application in some working environments because of its high failure rate.In order to overcome the shortcomings of the mechanical position sensor,this paper applies the position sensorless technology to the control of the permanent magnet synchronous motor.Firstly,this dissertation introduces the structure and classification of electric vehicles,the research status of sensorless control technology is summarized,and analyzes the advantages and disadvantages of several common control methods in the corresponding speed range.According to the principle of coordinate transformation,the mathematical model of PMSM in different coordinate systems is established,and the PMSM vector control system is modeled and simulated.Secondly,the basic principles of model reference adaptive method and high frequency voltage injection method and their applications in PMSM position sensorless control are introduced.In the low-speed range,the pulse high-frequency voltage injection method is used to detect the motor speed and the position of the rotor;the model reference adaptive method is used in the medium-high speed range,and the motor parameter is dependent on the method,and the motor parameter variation,especially the stator resistance change,is particularly Sensitive,which led to the improvement and optimization of the estimation speed inaccuracy and phase delay;the improved model was built and the traditional method was compared and verified,and the improved identification system was more accurate in estimating the rotational speed and rotor position.Finally,for the above single method is only applicable to the shortcomings in a certain speed range,this paper proposes a composite sensorless control method.The improved model reference adaptive method is combined with the pulse high-frequency voltage injection method,and the weighting function is used to smoothly switch the two methods to realize the sensorless control of the PMSM in the full speed range.Combined with the actual parameters and operating conditions of the electric vehicle drive motor,the simulation model of the composite control system was built in the MATLAB/Simulink platform to verify the effectiveness of the composite control system.Figure [111] Table [2] reference [62]...