Research On Parameter Identification And Control Of Permanent Magnet Synchronous Motor

Permanent magnet synchronous motor(PMSM)has the advantages of high starting torque,high power density and wide speed range,therefore the PMSM is widely used in electric vehicles,robotics,aerospace and other fields.In the PMSM control systems,position sensorless control,weak magnetic control and model predictive control need to know the exact information of the PMSM parameters.Therefore,in order to achieve the PMSM high performance control,it is crucial to know the correct information of the PMSM parameters.To address this problem,in this paper,the Big Bang Big Crunch Algorithm(BB-BC),Artificial Fish Swarm Algorithm(AFS),Genetic Algorithm(GA)and Differential Evolution Algorithm(DE)are used to identify the PMSM electrical parameters.And the Extended Sliding Mode Mechanical Parameter Observer(ESMMPO)methods with the system disturbance as the extended state is used to identify the mechanical parameters of the PMSM.On the basis of parameter identification and in order to realize the position sensorless control of PMSM,this paper uses the sliding mode observer(SMO)method to carry out the position sensorless control of the PMSM.The following parts will briefly summarize the main research of this paper.Firstly,the basic theory of the PMSM is briefly introduced.First,two PMSM structures,including the surface-mounted PMSM and the interior PMSM are introduced,and the merits and demerits of these two structures are analyzed.Second,the coordinate systems and coordinate transformations between coordinate systems,which are frequently used in the paper are introduced.The mathematical models of the PMSM are established in three-phase stationary coordinate system,two-phase stationary coordinate system and two-phase rotating coordinate system,respectively.Third,the vector control principle of the PMSM is analyzed and the framework of PMSM vector control model is built.Secondly,the BB-BC algorithm,AFS algorithm,GA algorithm and DE algorithm are used to identify the electrical parameters of the PMSM,including the stator resistance,d-axis inductance,qaxis inductance and permanent magnet flux.First,the identification framework of the PMSM electrical parameters is established and the integral time square error(ITSE)is selected as the parameter identification index.Second,the process of identifying the PMSM electrical parameters by four evolutionary algorithms are introduced respectively.Third,four algorithms are used in Simulink to identify the PMSM electrical parameters,and the identification results of these algorithms are compared and analyzed.The comparison results show that the AFS algorithm and the GA algorithm converge quickly and the identification results are highly accurate.Thirdly,the Extended Sliding Mode Observer Method(ESMMPO)is used to identify the mechanical parameters of the PMSM,including the viscous friction coefficient,the rotor inertia and the load torque.First,the ESMMPO method using system disturbances as extended states is introduced.In this method,the system disturbance of the PMSM is regarded as the extended states and observed.Since the mechanical parameters of the PMSM are contained in the system disturbance,this mechanical parameters of can be identified from the observation results.Second,there are many parameters need to be adjusted in the ESMMPO method,the improper selection of ESMMPO parameters will lead to inaccurate identification results,so the Cuckoo Search algorithm(CS)is used to adjust the parameters in the ESMMPO method.Third,the simulation model of ESMMPO method is built in Simulink.The simulation results show that the mechanical parameters of the PMSM identified by the ESMMPO method are precise,and the identification results identified by ESMMPO adjusted through CS are more accurate.Then,in order to realize PMSM position-sensorless control and use the identified PMSM parameters in the PMSM control system,an SMO-based method is used to realize PMSM positionsensorless control.First,the principle of position-sensorless control of the PMSM based on SMO method is introduced,which can observers the extended electromotive force(EEMF)value of the PMSM in two-phase stationary coordinate system.Second,according to the observed EEMF value,the arctangent function is used to calculate the rotor position and speed of the PMSM.Third,a simulation model based on SMO position-sensorless control is built in the Simulink.The simulation results show that the SMO method can correctly calculate the rotor position under different speed conditions and this method can track the given speed well under static conditions.Finally,a physical experiment platform for PMSM position sensorless control based on SMO is built.First,the hardware circuit design of the experiment platform is introduced.Second,the MATLAB code automatic generation function and its implementation process are introduced.Third,experiment is carried out on the experimental platform and the experimental results show that the control platform and the PMSM position-sensorless control based on SMO are effective.