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Research On Permanent Magnet Synchronous Motor Servo System Based On New Sliding Mode Control

Posted on:2018-10-04Degree:MasterType:Thesis
Country:ChinaCandidate:J ZhaoFull Text:PDF
GTID:2322330566955189Subject:Electrical engineering
Abstract/Summary:PDF Full Text Request
With the rapid development of modern science and technology,the application and field of servo control system have changed significantly,which plays an important role in industry,national defense and science and technology.Permanent magnet synchronous motor servo system is a strong coupling and multivariable nonlinear complex system,which requires high performance in harsh conditions.Sliding mode control(SMC)belongs to the category of nonlinear control,which is not sensitive to the variation of internal parameters and external load disturbance.It has good stability,fast response speed and easy to implement.The sliding mode variable structure is applied to permanent magnet synchronous motor,which can improve the control performance of the system.At the same time,the traditional mechanical sensors is limited to a certain extent the development of servo system.In order to solve the problems of manufacturing process and cost produced in the working conditions,this paper studies the sliding-mode control based on permanent magnet synchronous motor sensorless control technology.This thesis takes the permanent magnet synchronous motor servo system as the research object,the main work and the research contents are as follows:(1)The mathematical model in each phase coordinate system of permanent magnet synchronous motor is established,and the basic principle of vector control of permanent magnet synchronous motor is analyzed.The magnetic field oriented vector control strategy of id=0 was established.The voltage and space vector pulse width modulation technology is used to set up a double closed-loop permanent magnet synchronous motor servo control system of speed and current.(2)The basic principle of sliding mode variable structure is analyzed in detail,and the sliding mode variable structure is applied to permanent magnet synchronous motor servo system.In order to make up for the deficiency of the traditional exponential reaching law,a variable exponent reaching law is proposed,and the reachability is verified by the Lyapunov stability principle.In this paper,fuzzy control is added on the basis of variable exponent reaching law,and the variables are adjusted online through fuzzy control rules to achieve the purpose of reducing the chattering.The speed loop of permanent magnet synchronous motor servo system adopts fuzzy and sliding mode compound control,compared it with the servo system under the traditional PI control,the results verify the superiority of the fuzzy sliding mode controller.(3)The traditional sliding mode observer has the problems of phase angle lag of the rotor and sliding mode chattering.In order to remedy the above problems,a new type of sliding mode observer is designed.The hyperbolic tangent function is used to replace the symbol function in the sliding mode observer to solve the chattering problem caused by the discontinuity of the symbol function.The acquisition of rotor speed and position angle information adopts phase locked loop(PLL)control,which avoids the phase delay caused by the introduction of low-pass filtering.The speed loop of permanent magnet synchronous motor servo system selects the sliding mode control strategy with variable exponent reaching law.In order to verify its correctness,the simulation model of sensorless control of permanent magnet synchronous motor based on the new sliding mode observer is established,and compared with the traditional observer.The results show that the estimation precision of the speed and position angle of the new sliding mode observer is greatly improved.
Keywords/Search Tags:Permanent magnet synchronous motor, Sliding mode variable structure, Fuzzy control, Reaching law, Sliding mode observer, Phase-locked loop
PDF Full Text Request
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