Sensorless Control Of Permanent Magnet Synchronous Machine For Electric Vehicles

As one of the most rapidly developing new energy products in recent years,electric vehicles have received extensive attention from academia and industry.The Permanent Magnet Synchronous Machine(PMSM)and its control system,as the core module of electric vehicles,has also attracted increasing attention.Among them,sensorless control technology is one of the most popular research topics at present.In this paper,the permanent magnet synchronous machine for vehicles was investigated,and improvement were made according to the deficiencies of Model Reference Adaptive System(MRAS)based on PMSM.In addition,this paper put forward an Improved Model Reference Adaptive System(IMRAS)based on feed-forward torque load,and carried out simulation and experimental verification.The main research contents can be summarized as follows:1.An adaptive rate parameter tuning method for the MRAS is proposed,based on which the IMRAS is presented.The stability of the IMRAS is proven via the Popov’s hyperstability theory.Moreover,an adaptive rate parameter tuning method for the IMRAS is given out.The feasibility and effectiveness of the IMRAS is verified by simulation.2.A quantitative analysis is conducted to explore the parameter robustness of the IMRAS.According to the system stability conditions,the mathematical relationship between the speed observation error and the motor parameter error is obtained;and simulation results indicates the strong parameter robustness of the IMRAS.3.Due to the poor ability to suppress load torque disturbances and complicated parameter setting in traditional PI controllers,this paper proposes a speed controller with the load torque feedforward.By simplifying the motor mathematical model,the transfer function of the control system is obtained,before the dynamic performance of this system is analyzed in combination with simulation.The improved controller can well suppress the load torque disturbance and decrease the difficulty of controller parameter design,which was verified by simulation in its effectiveness and feasibility.4.Aiming at typical working conditions,the control method proposed in this paper is simulated and verified by experiments.Firstly,it analyzes and simplifies various actual working conditions to obtain three typical working conditions,and then performs simulation and experimental verification for the proposed algorithms under these typical working conditions.