Research On PMSM Current Predictive Control Based On Efficiency Optimization

Permanent Magnet Synchronous Motor(PMSM)is currently the technology of choice for high-performance motors for industrial and new energy vehicles.Its efficiency greatly affects the endurance of new energy vehicles and restricts its further development and application.How to improve the efficiency of the drive motor has become a challenging problem.This paper proposes a PMSM current prediction control method based on efficiency optimization,establishes a loss model,studies the selection of the reference current operating point at a given torque and speed,and makes it the most efficient set of dq-axis currents for the motor.Control(MPC)realizes current optimization control.Simulations and experiments verify the feasibility of the scheme.First,the mathematical model of PMSM is introduced.The loss of the motor is analyzed to explore the cause of the loss.The PMSM loss model is established by theoretical derivation,including copper loss,stator iron loss,mechanical l oss,rotor eddy current loss,and stray loss.The loss minimization is defined as the optimization problem under constraints.The specific idea is to find the reference current operating point under the given torque and speed requirements under the constra ints of voltage and current.Secondly,the initial dq axis current value under the torque target is obtained through the maximum torque current ratio(MTPA)strategy,and it is input into the PMSM reference current solution algorithm based on efficiency op timization,that is,under the constraints of voltage and current,by Find the working point of dq-axis current under target torque and speed.The solution algorithm is divided into 6 categories according to the voltage and current constraints,and the pos ition of the torque curve is different.The initial value reference value and the position of the constraint equation are determined to determine the current vector.Primary current reference value.Therefore,the motor is driven with the minimum current,the motor loss is minimized,and the efficiency is optimized.Then,the model predictive current optimization control strategy is proposed,and the dq axis reference current based on efficiency optimization is adopted to realize PMSM current control by using FCS-MPC and simplified MPC algorithm for selecting vector numbers.The former uses the enumeration method to select the ideal voltage vector,so its calculation amount increases exponentially with the increase in the number of switches;the latter calculates the expected vector angle and finds the voltage vector is located in the sector,which can reduce the number of switch state calculations.Significantly reduced,improving the accuracy and reliability of current control.Finally,based on the MATLAB / Simulink software platform,this paper builds a PMSM current prediction control simulation model based on efficiency optimization,and uses DSP control modules to build a system experiment platform.Simulation and experimental results show that the effectiveness of the optimized control algorithm proposed in this paper can further reduce losses and improve efficiency compared with traditional methods,and the control method is more stable and superior.