Research On Online Parameter Identification And Efficiency Optimization Control Of Asynchronous Motor

Induction Motor(IM),is widely used in various industries such as industry,agriculture,and transportation because of its simple structure,durability,and low price.Its electricity consumption accounts for industrial electricity more than 60% of the total.However,the commonly used asynchronous motors have the drawback of low overall efficiency.Due to the influence of temperature variation,magnetic saturation and skin effect on the asynchronous motor,the parameter variation has nonlinear characteristics,and inaccurate parameters in the model of motor can affect the dynamic performance of the motor.Aiming at the problems of asynchronous motor,this paper designs a motor backstepping control system with parameter estimation and efficiency optimization based on vector control method,backstep control method,model reference adaptive theory and energy efficiency optimization principle.The control performance of the method is verified by simulation.First,the purpose and significance of this research are explained.The current research status of IM speed control system,IM parameter identification method and efficiency optimization control are introduced.Secondly,it introduces the IM mathematical model that needs to be used in this paper,and simplifies the IM mathematical model by using coordinate transformation.The IM vector control method is preliminarily studied,and the control principle and structure of the IM vector control system are introduced.Thirdly,aiming at the parameters that will change during the operation of the IM control system,using the model reference adaptive theory and the Popov's superstability theorem,the IM rotor resistance and rotor time constant identification model are designed.And identify and change the system parameters in real time.Also feed back to the controller.The simulation performance of the system is tested by the simulation experiment,and the performance of the proposed parameter identification method is verified.Fourthly,the scheme of designing the motor controller by backstepping method is studied.At the same time,the load torque observer of the motor is designed to realize the real-time observation of the load torque,and the parameter identification model is applied to the changed parameters.Finally,the simulation experiment analysis of IM backstepping control with parameter identification is given.It is verified that the proposed scheme can effectively improve the dynamic performance of the system and improve the robustness of the disturbance.Fifthly,the source of loss of IM control system is analyzed,and the mathematical model of loss of IM control system is given.Then a calculation scheme of optimal excitation current based on mathematical model is proposed.The simulation results show that the proposed scheme can reduce the energy loss of the IM control system at steady state and effectively improve the operating efficiency of the motor.In summary,this paper takes the asynchronous motor speed control system as the research object,and studies the nonlinear variation of the asynchronous motor parameters and the low operating efficiency.The back stepping control and parameter identification and motor efficiency optimization algorithms are used.Online identification of parameters and improves the operating efficiency of the motor in steady state operation are realized.The proposed control strategy has good practical application value.