Finite-time Control Of Chaos In Permanent Magnet Synchronous Motor

Permanent magnet synchronous motor (PMSM) is extensively used in the speedcontrol system and servo system. However, in some cases, chaos appears in PMSMwhen the parameters are in a certain range. These chaotic phenomena seriously affectthe stable work of the PMSM system. In order to eliminate the chaos in permanentmagnet synchronous motor, many scholars have proposed different control methods.However, most of these methods discussed in permanent magnet synchronous motorsystem are asymptotically stable methods, and in some practical applications, finitetime control method may have better results in the control speed and robustness.Therefore, this article aims to use the finite-time control method to eliminate thechaos in permanent magnet synchronous motor, and make it to reach the steady statemore quickly in a finite time.In addition, what need to be considered is that the parameters of chaotic PMSMsystem may be unknown, or the exact values of the parameters are difficult to be gotbecause of environmental factors such as temperature, voltage shock, the mutualinterference between the components and so on. Then adaptive control method is usedto estimate the unknown parameters. And combined with the finite-time controlmethods, we proposed the adaptive finite-time chaos-control law of the PMSMsystem.This thesis firstly describes the development of chaos theory as well as the statusof chaos control study at home and abroad, and then gives a brief analysis ofcharacteristics and problems in the current chaos suppression in permanent magnetsynchronous motor. After that, this thesis proposes a finite-time control method tosuppress the chaos in permanent magnet synchronous motor based on themathematical model of the motor. Then an adaptive finite-time chaos controlmethods considering is used to suppress the chaos in permanent magnet synchronouswhen the parameters of the system maybe unknown. Finally, the adaptive finite-timecontrol method is improved, because of reducing the number of the control inputs.MATLAB simulation verifies the effectiveness and superiority of the proposedthree methods in controlling chaos. Simulation results show that the proposedmethods can not only eliminate the chaos in permanent magnet synchronous motors, but also can make the motor system to reach steady state quickly in a finite time, andthe controlled system has good robustness.