Research On The Dead-beat Predictive Current Control Of Permanent Magnet Synchronous Motor Based On Luenberger Observer

Permanent magnet synchronous motor is widely used in new energy vehicles,aerospace,robotics,medical equipment and other fields due to its advantages of simple rotor structure,low production and maintenance costs,stable operation,and high-speed drive.In order to meet the increasing demand of control accuracy in the cutting-edge field,scholars from various countries have proposed many excellent control algorithms,and the dead-beat predictive current control is one of them.Compared with the traditional PI control,the dead-beat predictive current control has the advantages of predictability and fast dynamic response.It can make the motor more quickly when switching working state or returning to the normal state when it is disturbed.However,the dead-beat predictive current control is very sensitive to the changes of the motor parameters.Once there is a parameter deviation,the system will have a current error phenomenon,which will affect the control performance.When the parameter deviation becomes serious,it may even cause the system to collapse.In order to solve the problem of the strong sensitivity of the dead-beat predictive current control algorithm to the motor parameters change.In this thesis,a Luenberger observer is designed to observe the motor parameter disturbance in real time,and corrected the expected voltage vector output by the prediction model.The simulation results show that Luenberger observer can effectively reduce the dependence of the prediction model on the motor parameters and eliminate the effect of current static error.This thesis refers to the nonlinear relationship between the estimated error of the extended state observer and the observer gain,namely the design concept of"large error small gain,small error large gain".This thesis proposes a variable gain Luenberger observer,which gives different gains for different error conditions.Large errors such as the motor starting stage,give the observer a small gain,small errors such as the motor parameters change during operation,give the observer a large gain,thus the performance of the observer can be further improved.The simulation results show that the variable-gain Luenberger observer can effectively improve the dynamic stability of the system and reduce the estimation error of the observer.Finally,the experimental verification was carried out on the permanent magnet synchronous motor-DC motor mutual dragging experimental platform,and two deadbeat current predictive control algorithms based on the traditional Luenberger observer and the variable gain Luenberger observer were realized,and the experimental result is analysed.The experimental results show that the variable gain Luenberger observer can effectively improve the dynamic performance of the system.