Research On Continuous Terminal Sliding Mode Control Method For Permanent Magnet Synchronous Motor Speed Regulation System

With the fast development of power electronics technology, the modern motor control technology, microelectronic technology and computer control technology, permanent magnet synchronous motor (PMSM) servo system has been widely used in control applications such as robotic systems, spacecraft systems, industrial control systems, etc. At the same time, the modern industrial requirements for performance of motor control system are getting higher. Furthermore, the working environment of motor control system becomes much more complicated. Therefore, conventional PI control method is difficult to provide a satisfactory performance, especially in high-precision control situations. This paper makes some research about the applications of the continuous terminal sliding mode control method in PMSM speed regulation system which is under vector control framework.First, the paper introduces the structure, working principle, control strategies and control methods of PMSM system and focuses on analyzing of mathematical mode of PMSM. Based on this model we employ a framework of vector control where a cascade control structure including a speed tracking loop and two current tracking loops is employed. The decoupling method of zero d-axis current, id=0 is also applied. Second, this paper introduces not only the principle of sliding mode control method, but also the advantages and disadvantages of the traditional liner sliding mode control method and terminal sliding mode control method. Then, through studying finite time control method, a continuous terminal sliding mode control (CTSMC) method is proposed, which is one method of finite time control methods for the PMSM system. Simulation comparisons show the CTSMC method can achieve a better convergence and disturbance rejection than the corresponding linear sliding mode (LSM) control method. In order to further improve the disturbance rejection ability, two current tracking loops are also designed by using controllers base CTSMC method in the fourth part. Simulation results are also presented. At the last of this paper, a control method is proposed. The method transforms the PMSM system into two subsystems. One is a first order d-axis current error tracking system; the other is a second order velocity error tracking system. These two controllers are designed by using first order CTSMC and second order CTSMC. The simulation results show the effectiveness of the designed method.