Research On Speed Sensorless Control Algorithm Of Induction Motor Based On The Adaptive Full Orde Observer

In order to solve the increasingly prominent shortage of crude oil supply and environmental pollution problems,new energy vehicles have been widely concerned,and have been rapidly developed under the incentive of series of policies and tend to be popularized.Because of its low cost,high speed performance and mature design technology,asynchronous motor is widely used in new energy vehicle electric drive.Vector control can achieve good steady-state and dynamic performance and become the mainstream control scheme of induction motor.As an important information of vector control algorithm,speed is obtained by mechanical components such as rotation and photoelectric encoder,which not only increases the cost of control system,but also increases the complexity of installation and wiring,and reduces the reliability of the system.Therefore,speed sensorless control has become a hot and difficult problem in academic research。The full order observer is favored because of its good observation accuracy and convenient engineering implementation.However,the stability of the full order observer of asynchronous motor,especially the stability of low speed regeneration mode,has not been solved well,which seriously restricts the low speed performance of the speed sensor control system.The low speed and high torque load characteristics of electric vehicles make the problem of low-speed stability of speed sensorless control system more prominent.On the basis of the deep analysis of the low speed stability of the full order observer,this paper compares and studies the existing improvement schemes for the stability lifting,and proposes a full order adaptive observer scheme based on the error weighted self-adaptive law,which effectively improves the low speed stability and dynamic performance of the observer.The main work of this paper is as follows:1.on the basis of establishing an adaptive full order observer transfer function,the distribution of its characteristic root is discussed,and the reasons for its instability are analyzed based on this.2.the unstable working region of the traditional self-adapting full order observer is introduced by using the Routh Holzer viz stability criterion.3.of the existing adaptive law schemes are analyzed and the existing problems are discussed.4.a full order adaptive observer scheme based on the error weighted self-adaptive law is proposed.The scheme directly introduces the excitation current component error into the rotational speed adaptive law and is designed by the weight coefficient.The 5.trajectory comparison analysis shows that the proposed adaptive full order observer scheme has better steady-state and dynamic performance compared with the existing improved scheme.6.in order to further reveal the correlation between the two kinds of stabilization methods based on the feedback matrix design and the adaptive law design,there are two kinds of parties.The case carries on the analysis of the transfer function and the root locus to reveal the equivalence of the two in performance,and designs its corresponding error feedback matrix scheme or the same operating performance according to the error weighted adaptive law designed in this paper.7.the experimental platform of asynchronous motor is set up,and the vector control of the asynchronous motor is designed.The adaptive observer and its speed sensorless control system are simulated.