Research On Model Predictive Fault-tolerant Control Of Demagnetization Fault For Permanent Magnet Synchronous Motor

Permanent magnet synchronous motor(PMSM)has been widely used in transportation,industrial production and other fields due to its advantages of simple structure,strong stability and no energy consumption in rotor.It also operate under various complex and changeable environment and operation conditions.So,its permanent magnet is easy to demagnetized,which greatly affects the control performance of PMSM.In this paper,the finite control set-model predictive control(FCS-MPC)based on the sliding mode observer for PMSM is discussed.The main research contents of this paper are as follows:In view of the problem that the permanent magnet of PMSM is easy to take demagnetization faults under the complex traction conditions,a finite control set model predictive fault-tolerant control method based on flux online detection is proposed.Firstly,the characteristics of permanent magnet demagnetization faults are analyzed,and the mathematical model of permanent magnet synchronous motor under demagnetization faults is established.Secondly,the permanent magnet flux observer is designed to observe the rotor flux in real time,and the stability of the observer is proved.Finally,a fault-tolerant control algorithm based on the FCS-MPC is proposed,and the observed flux information is fed back to the finite control set model predictive fault-tolerant controller,so that the motor parameters in the predictive model are consistent with the actual parameters of the motor.It can reduce the influence of the permanent magnet demagnetization faults on the control performance of the PMSM,so as to realize the finite control set model predictive fault-tolerant control for demagnetization faults.The simulation and experimental results show that compared with the traditional PI control,the fault tolerance and robustness of the finite control set model predictive fault-tolerant control method are stronger.In order to solve the problem that the permanent magnet of PMSM is easy to take demagnetization faults under the complex traction conditions,the control method proposed above is improved,and a two-vector FCS-MPC based on flux linkage on-line detection is proposed.Firstly,the traditional first-order sliding mode observer mentioned above is replaced by the super twisting sliding mode observer,which makes the observed flux information more accurate and eliminates the chattering of the traditional sliding mode observer.Secondly,the traditional single vector FCS-MPC is replaced by the two-vector FCS-MPC,and the one order forward discrete method is replace by the higher accuracy second-order Euler discrete method to obtain the predictive model,which make predictive model more accurate.Finally,the simulation results show that,compared with the single-vector FCS-MPC and traditional PI control method,the proposed two-vector FCS-MPC algorithm based on flux online detection can adapt to the control environment with higher control accuracy requirements,and further improve the control performance of PMSM.