Research On Direct Torque Sliding Model Control Of Permanent Magnet Synchronous Motor Based On Active Disturbance Rejection

Permanent magnet synchronous motor(PMSM)has been extensively used in the field of industrial control due to its high power density,high efficiency,high reliability and other characteristics.At present,the research of PMSM control system has been extensively concerned,how to effectively control PMSM plays an important role in promoting social progress,improving production efficiency,saving energy and reducing emissions.As a kind of high performance AC speed regulation method,direct torque control method has the characteristics of simple structure,quick response and so on.Therefore,the direct torque control of PMSM has become a hot topic in the field of modern AC speed regulation.In this paper,PMSM is taken as the research object,firstly,its structures,characteristics and set up the mathematical model of two phase rotating coordinate system.Then,based on the analysis of the theory of direct torque control,a simulation model of PMSM direct torque control system is established.The simulation results show that,the system has many problems such as large torque ripple and poor immunity.To solve these problems,this paper makes two improvements on the original system.One is using the theory of sliding mode control to improve the torque loop,which is adopting super-twisting sliding mode controller to replace the hysteresis comparator in torque loop and use space vector pulse width modulation instead of voltage switch table.The sliding mode controller can effectively reduce the torque ripple through the smooth control of the magnetic chain and torque.Meanwhile,in order to further reduce the system buffeting,a hyperbolic tangent function is used to continuously control the quantity.The other is using the active disturbance rejection control technology to improve the speed loop,which is adopting active disturbance rejection controller(ADRC)to replace the PI controller in speed loop.The ADRC achieves the accurate electromagnetic torque setpoint by smoothing the input signal,estimating the disturbance in real time,and finishing the feedforward compenstation.Meanwhile,in order to reduce the adjustable parameters in ADRC,the variable structure control is proposed to improve it,so as to make it simple and retain the original features.Finally,on the basis of theoretical analysis,a simulation model of PMSM direct torque sliding mode control system based on active disturbance rejection control technique is established.The simulation results show that the improved system has the advantages of good dynamic performance,small torque ripple,strong immunity and good robustness.