Research On Optimal Control Of Interior Permanent Magnet Synchronous Motor Based On Parameter Identification

Interior in Permanent Magnet Synchronous Motor(IPMSM)is gradually promoted to replace traditional motors such as induction motors and DC motors due to its advantages of high efficiency,reliable operation,and high power density.The Maximum Torque Per Ampere(MTPA)control strategy is a commonly used control strategy for IPMSM.This control strategy can maximize the use of the reluctance torque of IPMSM,and effectively reduce the current of IPMSM,thereby improve its operating efficiency.The traditional MTPA control strategy has a great dependence on the motor parameters,and the temperature rise of the motor and the saturation effect of the magnetic circuit of the dq-axis will cause the inductance parameters to change,which leads to the inability to maximize the use of reluctance torque in the control.The working current of the motor increases,and the operating efficiency of the motor decreases.In response to this problem,this paper deeply studies the influence of parameter changes on the control system and the parameter identification algorithm of the motor,and uses parameter identification to optimize the MTPA control based on the formula method.The core content is as follows:1)The influence of motor parameter changes on the control system is studied.In this paper,the finite element model of PMSM is first established in the software,so as to obtain the change curve of inductance with current.Then the parameterized current loop and speed loop PI controllers are designed.On this basis,the influence of the motor parameter changes on the control system is studied.Finally,the influence of the parameter changes on the traditional MTPA control strategy is studied on the basis of the closed loop control system.2)In order to track the parameter changes of the motor in real time,this paper deeply studies the parameter identification algorithm,analyzes the limitations of the traditional parameter identification algorithm.On this basis,this paper proposes a step-by-step parameter identification method,which can consider the nonlinearity of the voltage source inverter,it can realize the identification of the inductance of the dq-axis,the stator resistance and the permanent magnet flux linkage.3)This paper proposes a MTPA optimization control strategy based on step-by-step parameter identification algorithm.Firstly,the high-precision inductance parameter identification of the motor is carried out under different currents,and the inductance current curve is used to optimize the MTPA control strategy in real time,thereby improving the calculation accuracy of the MTPA optimal current angle and the working efficiency of the motor.In summary,this paper studies the motor parameter identification algorithm and the effect of motor parameter changes on the MTPA control strategy,proposes a step-by-step parameter identification method,and based on this method,studies the MTPA optimized control strategy of permanent magnet synchronous motor The method proposed in this paper is verified by simulation and experiment.The experimental results show that the method can effectively solve the problem of the sensitivity of the traditional MTPA control method to motor parameter changes,and has good engineering application value.