Research On Load Simulation System Based On Permanent Magnet Synchronous Motor

Motor is a vital actuator in several industries,like automobile,electrical equipment,machinery,national defense and aerospace.With the constant development of science and technology,the dynamic performance requirements of the motor’s load are continuously improved.In the laboratory environment,it is not possible to meet a variety of operating conditions at the same time.Therefore,a load simulation system is needed to simulate the complex and diverse loads that the motor undertakes during operation,and is used for dynamic performance testing of the motor.In this paper,we have used the permanent magnet synchronous motor as a mathematical model.In order to satisfy requirements of the load simulation system to perform with a higher precision,a responsible speed.We also have selected the direct torque control as a strategy to control this system and the Space Vector Pulse Width Modulation(SVPWM)to play the role of the hysteresis control in traditional direct torque control,which can reduce the torque ripple and improve the stability of the syst’em.Firstly,the mathematical model of permanent magnet synchronous motor and three-phase voltage reconstruction method are introduced,Secondly,estimation module was designed based on voltage and current mixed fluxed observer to calculate the stator flux linkage,and we focused on analyzing the selection process of reference voltages.These make it possible to realize the direct torque control technology of SVPWM.Finally,the simulation model of traditional DTC and SVPWM DTC were built on Matlab/Simulink platform,and we also compared and analyzed their performances.On the basis of theory,firstly,the load torque characteristics,of several typical loads are studied,and the mathematical equation of load simulation system is deduced.T,hen,the system output torque is obtained through the mathematical model of the motor without the torque sensor,which has reduced the cost of hardware.In ord,er to,prevent it too highspeed,we added a speed limiting control into this system.The machanical shaft decouping function of two motors in the motor test platform was derived,and the SVPWM DTC model of the motor test platform was built on the Matlab simulation platform.On the basis of theory and simulation,the main hardware circuit and algorithm program of the system are studied.The main controller of TMS320F28335 is used as the main controller of the system,and the experimental platform of load simulation system is built.Through experimental verification,the load simulation system designed in this paper can realize the simulation of constant torque load,constant power load and fan pump load.The experimental results show that the system has fast dynamic response performance and is consistent with theoretical analysis and simulation results,which proves the feasibility of the control strategy.