| Permanent magnet synchronous motor(Permanent Magnet Synchronous Motor,PMSM)has the advantages of high operation efficiency,small volume,strong antiinterference,and has been widely used in high power systems and high performance occasions.In PMSM drive technology,the maximum torque current ratio control(Maximum Torque Per Ampere,MTPA)can give full play to the inherent characteristics of built-in permanent magnet synchronous motor(Interior Permanent Magnet Synchronous Motor,IPMSM)alternating and direct axis inductance,so that there is magnetoresistance torque component existing in the electromagnetic torque,so as to improve the torque output capacity and operation efficiency of the motor.However,the MTPA control strategy largely depends on the operating parameters of the motor,and the operating parameters will change nonlinear by factors such as magnetic circuit saturation and iron consumption,leading to the deviation of the motor from the optimal running trajectory.Therefore,in order to obtain accurate operating parameters and realize high-precision MTPA trajectory tracking,this paper designs and improves the online identification algorithm based on the optimized motor model.The main research contents are described as follows:(1)Aiming at the problem that the traditional mathematical model cannot accurately reflect the parameter changes in motor operation,an accurate mathematical model considering the saturation of the magnetic circuit and iron consumption is designed based on finite element analysis.The accurate model can reflect the nonlinear changes of motor parameters under different working conditions in real time,and provide a model basis for the realization of accurate MTPA control strategy.The simulation results verify the correctness of the design scheme and can reflect the real operation state of the motor.(2)Aiming at the problem of underranking in multi-parameter identification,a composite identification scheme is designed by combining the least squares method and the model reference adaptive algorithm to realize multi-parameter online identification.The solution can simultaneously identify the four parameters of D-axis inductance,Qaxis inductance,permanent magnet flux and stator resistance.At the same time,in order to realize the parameter identification under different working conditions,an improved model reference adaptive identification algorithm is proposed based on the accurate model,which realizes the accurate identification of parameters by introducing the realtime optimization adaptive law of dynamic initial value.Based on this,a multiparameter identification scheme considering the nonlinear change of parameters is designed by using the step-by-step method and introducing dynamic fixed values,and the simulation results verify the correctness of the scheme and the accuracy of the identification when the nonlinear changes of the parameter method.(3)The IPMSM accurate model is built in Matlab/Simuilink,and the improved multi-parameter recognition algorithm is applied to the MTPA control system based on the accurate model to realize multi-parameter online identification.The simulation results show that the new model can realize real-time tracking of parameter changes,reduce the dependence of traditional MTPA control on accurate parameters,effectively solve the problem of maximum power output,and improve the stability of the system. |
