Font Size: a A A

Research On Sensorless Sliding Mode Control Strategy Of Fractional Order Permanent Magnet Synchronous Motor

Posted on:2021-01-18Degree:MasterType:Thesis
Country:ChinaCandidate:Y N LiFull Text:PDF
GTID:2392330602489065Subject:Control Science and Engineering
Abstract/Summary:PDF Full Text Request
Permanent magnet synchronous motor(PMSM)is widely used because of its simple structure,small volume,fast response,high torque inertia ratio and reliable operation.Rotor position tracking and speed control of PMSM is the key to achieve high performance control,and sliding mode control has become the first choice of motor control system because of its strong robustness and anti-interference ability.With the development of fractional calculus theory and its research and application in various disciplines,engineering and industrial fields,fractional calculus can be used to establish a more accurate mathematical model for the control system,and the controller with better performance can be designed by combining the double advantages of fractional calculus and sliding mode control,so that the control system can obtain better control performance.In this paper,the fractional calculus theory is used to study the speed control of PMSM from three aspects:the modeling of speed control system,the design of fractional sliding mode observer and the design of fractional sliding mode controller.Firstly,the integral order mathematical model of PMSM is established,and its order is extended to fractional order.The feasibility of fractional order model is verified by simulation.The fractional mathematical model is divided into two parts:the electromagnetic part and the mechanical part.The parameters of these two parts are identified by the identification algorithm based on Levernberg-Mardquart algorithm,and then the two parts are synthesized to get the fractional mathematical model of PMSM.The same identification algorithm is used to get the integer order mathematical model.The simulation results show that the fractional order model can describe the actual characteristics of PMSM more accurately than the integer order model.Secondly,in order to track the rotor position of PMSM accurately,a fractional order sliding mode observer based on Kalman filter is proposed by introducing fractional calculus principle on the basis of traditional sliding mode observer.Based on that,a second-order sliding mode observer based on the fractional super spiral algorithm is designed to solve the chattering problem in sliding mode control.Simulation results show that the method can effectively suppress chattering and improve the observation accuracy and system robustness.Considering the influence of external mismatch disturbance and internal parameter uncertainty on the control system,a fractional order disturbance observer is designed for the fractional order motor model.The synthetic back electrodynamic force is regarded as the external disturbance and the fractional disturbance observer is used to estimate it.According to the estimated results,more accurate rotor position information can be obtained by corresponding phase compensation,thus improving the control accuracy of the system.Finally,based on the fractional order mathematical model and the fractional order sliding mode observer,a fractional order sliding mode control method based on the fractional order disturbance observer is,proposed.The load disturbance reconstructed by fractional disturbance observer is introduced into the controller to offset the influence of load disturbance on the system,and its effectiveness is verified by simulation.In order to improve the speed control accuracy of PMSM,a new dual power approach law is proposed to solve the problems of long convergence time and many parameters to be set in the basic dual power approach law.The fractional order integral sliding mode controller is designed by combining it with fractional order integral sliding mode surface.The simulation results show that compared with the fractional order sliding mode controller,the fractional order integral sliding mode control can accelerate the response speed of position tracking and the tracking error is smaller.At the same time,aiming at the chattering problem of fractional sliding mode,a second-order sliding mode controller based on the fractional super spiral algorithm is designed.The simulation results show that the controller can effectively reduce the tracking error of the system and further weaken the chattering.
Keywords/Search Tags:permanent magnet synchronous motor, fractional calculus, fractional order sliding mode observer, fractional sliding mode controller
PDF Full Text Request
Related items