Research On Speed Control Method Of Permanent Magnet Synchronous Machine Based On Loss Minimization Target

With its outstanding characteristics,such as simple structure,strong overload capacity,and high operating efficiency,Permanent Magnet Synchronous Machine(PMSM)has been broadly used in the fields of robots,electric vehicles,aerospace,etc.Most studies on PMSM do not consider the iron loss.This paper takes the permanent magnet synchronous motor considering iron loss as the main line,and involves four aspects of PMSM: multi parameter online identification method,loss minimization control method,speed control method and sensorless control method.In order to eliminate the influence of parameter changes of PMSM on energy-saving control and speed control,based on the PMSM model considering iron loss,a model reference adaptive system with parallel structure is adopted to realize online multi-parameter identification,which avoids the problem of under rank in the conventional multi parameter identification method.In order to solve the problem that the search-based loss minimization method of PMSM has long search time,high requirements for equipment,and the model-based loss minimization method can not be used for interior permanent magnet synchronous motor(IPMSM),a loss minimization control method based on virtual power loss with current compensation is proposed.The power loss of PMSM is reconstructed by superimposing small signals,which avoids the problem of additional power loss caused by injecting signals into the system.Expand the Taylor series of the reconstructed virtual power loss,ignore its high-order terms,and design an integrator by using the derivative symbols on the left and right sides of the loss minimization point to accurately track the loss minimization operating point of the PMSM,so as to realize the loss minimization control of PMSM.In order to improve the speed regulation performance of PMSM,a speed control model considering iron loss is established,which connects the energy-saving of motor with speed control.At the same time,aiming at the uncertain disturbance in the speed regulation system,a new sliding mode reaching law and a new sliding mode observer(SMO)are proposed.The new SMRL can estimate the uncertain disturbance in the system,adaptively adjust the speed approaching the sliding mode surface and reduce the sliding mode chattering.The new SMO based on the dynamic equation of sliding mode surface has little dependence on the system parameters,and high robustness,which realizes the estimation of uncertain disturbances.In order to improve the sensorless control effect of PMSM,a sensorless control model of PMSM considering iron loss is established,and the influence of iron loss on sensorless control is analyzed and solved.An adaptive SMO is designed to reduce chattering in the estimated back electromotive force(EMF).Aiming at the problem that the traditional phase-locked loop(PLL)can not track the rotor position with zero steady-state error under acceleration and deceleration conditions,the corresponding improvement is made based on the transfer function model of PLL,and the problems of PLL under acceleration and deceleration conditions are eliminated.