Research On High Performance Control Strategy Of Permanent Magnet Synchronous Motor Based On Disturbance Compensation

Permanent magnet synchronous motor(PMSM)drives are widely used in industry and commercial drives due to its merits in high efficiency,high power density,wide speed range and low noise.At present,for the reason that the linear PI method possess the characteristic of simple implementation,it is still dominant in PMSM control system.However,there are large quantities disturbances and uncertainties in practical PMSM system,that means when the motor encounters parameter disturbance and load changes during operation,the control scheme based on PI method is difficult to ensure high performance requirements in some occasions.Therefore,sliding mode control and model-free control are proposed in this paper and they are applied to redesign the speed controller of PMSM.Meanwhile,disturbance compensation strategies are introduced to combine with the designed speed controller,and then the composite control theory that based on disturbance compensation is presented for PMSM to adjust the control quality and robustness of closed-loop system.The main contents of this paper are as follows:Firstly,in order to optimize the response speed of PMSM and obtain satisfactory tracking performance and robustness,a composite control theory by including integral sliding mode control(ISMC)and nonlinear disturbance observer(NDO)is proposed.Among them,the single-loop speed controller that obtained by using ISMC method improves the dynamic response performance of PMSM and mitigates the difficulty of tuning controller parameters.And,aim at the attenuation of speed tracking performance caused by load and other uncertainties,a NDO is applied to estimate the mismatched disturbance that survive in the system,and the estimated value is regarded as fed-back part for the speed controller to mitigate the effect of disturbance.Finally,the comparison between ISMC+NDO and PI method are completed by experimental platform.Then,take into account that design process of the above SMC controller rely on the motor dynamic model excessively,but the parameter perturbation and unmodeled dynamics are easily to be appeared when the motor works under complex conditions and environment.Thus,the MFA control is adopted and combined with DITSMC method to propose a speed-loop controller for PMSM,which has less sensitive to mathematical model and time-varying parameters.To further enhance the ability of reject disturbance for closed-loop system,this paper introduces two solutions for the presented MFA-DITSMC controller.(1)The predictive control is combined with MFADITSMC speed controller,a novel MFA-DITSMPC controller is obtained,and the experimental results exhibit that,the novel controller can guarantee fast speed tracking and suppress the load disturbance well when the predictive control is added.(2)By using the idea of combining the observer with MFA-DITSMC controller,through recommend the NDO and ESO,respectively,two novel speed control strategies(MFADITISMC+NDO and MFA-DITSMC+ESO)are presented.Experimental contrast results demonstrate that,the designed method can significantly improve the ability of disturbance attenuation while ensuring satisfactory dynamic performance.Finally,to simplify the structure of controller and advance the speed tracking performance,a single-loop control approach is presented for PMSM by adopting MFNTSMC and FTDO.To realize the model-free control,the speed motion equation and quadrature axis voltage equation of PMSM need to be transformed into a ultra-local model primarily.Then based on the proposed nonsingular terminal sliding mode surface,a MF-NTSMC controller is proposed for PMSM through the ultra-local model,meanwhile,a disturbance estimation method that depended on FTDO is proposed for PMSM control system,and the estimated value is used for feed forward compensation of controller.Finally,experimental results under different given conditions show the validity of the designed algorithm.