Built-in PMSM With Minimum Loss Predictive Current Control

Interior permanent magnet synchronous motor(IPMSM)has the characteristics of simple structure,reliable operation,high mechanical strength and high power density.The rotor magnetic circuit structure of IPMSM is asymmetric,and the torque output capability of the motor can be improved by utilizing the reluctance torque generated by this asymmetry.Interior permanent magnet synchronous motor has been widely used in various industrial fields.It is of great significance to improve the operating efficiency of motor and reduce energy consumption.In order to improve the efficiency of the motor,the method of improving the motor loss minimization control strategy can be adopted.However,the traditional loss minimization control method based on search technology has slow convergence speed,and the traditional loss minimization control method based on loss model is difficult to obtain accurate equivalent resistance value of the iron consumption.In addition,the traditional method can not accurately track the given value of the optimal control variable,which makes it difficult to further improve the operation efficiency of the motor.Based on the establishment of the motor loss model,this thesis conducts in-depth research and analysis on the loss minimization control of the internal permanent magnet synchronous motor.In order to solve these problems,this thesis puts forward a loss minimization predictive current control strategy of interior permanent magnet synchronous motor based on real-time observation of iron loss.Firstly,the equivalent circuit of the motor in the d-q rotating coordinate system is obtained under the premise of considering the influence of the iron loss of the motor.The various components of the stator current are calculated online by Kalman observer,and the iron loss of the motor can be obtained by further calculation based on the observation results.Then,the given value of the stator d-axis current torque component that can make the motor in the state of minimum loss is obtained by derivation and calculation.Compared with the traditional method based on loss model,the proposed method does not need to carry out the complex parameter tuning and finite element model construction of the motor.In addition,in order to accurately track the given value of the steady-state stator d-axis current torque component,the current observation results are introduced into the current prediction process.The predictive control method is used to predict the output current results,and the value function is constructed to select the optimal voltage vector that can meet the load demand,so as to reduce the current tracking error,improve the current prediction accuracy,and further improve the operation efficiency of the internal permanent magnet synchronous motor.On the basis of theoretical analysis,the simulation and experiment platform for interior permanent magnet synchronous motor are built to verify the validity of the proposed loss minimization prediction current control strategy based on on-line observation of iron loss in this thesis.The simulation and experimental results show that the proposed method can effectively reduce the motor loss and improve the motor operation efficiency.Moreover,it also has good dynamic performance.