Study On Chaos And Controlling Chaos In Multi-motor Complex Network

Permanent Magnet Synchronous Motor (PMSM) is an energy transfer device, which has re-placed traditional electrically excited synchronous motor and has been widely used in such areas as rail transportation, industry, agriculture and aerospace and other fields. The complexity of op-eration in the motor drive system has been increased with the interconnection between large-scale motors, thus the secure and stable operation of motor drive system, which is an es-sential requirement of industrial manufacturing, has been received considerable attention. Therefore, it is of great significance in theory and application for industrial security to study the chaotic behaviors of complex motor networks and to provide corresponding strategies for chaos control.In this paper, we analyze the chaotic behavior of the scale-free network model of PMSM as well as the chaos control methods for the small-world network model of PMSM in two distinct circumstances.Main contributions of this research are summarized as follows:(1) The problem and rationale of research are stated based on the review of literature in the chaos control for complex motor networks.(2) The existing chaotic models of PMSM are summarized with the chaotic properties illus-trated. The non-linear dynamic model in scale-free network of PMSM are given and the influ-ences of network topology and coupling strength on the stability of the scale-free network of PMSM are examined when each component is stable. The critical parameters, with which chaos are induced in the complex motor networks, are investigated by analytical methods.(3) In the case where the nodes in the complex motor networks are comparatively fewer, an environment-based chaos control method for the small-world network of PMSM is proposed in reference to the linear stability theory. Results of process simulation and property analysis are also given. The proposed method is superior in terms of design and implementation because only one over-damped dynamic system is coupled with all the nodes in the complex PMSM network.(4) When the nodes in the complex motor networks are numerous, a pinning method for controlling small-world network of PMSM and its verification results are provided in accordance to the Lyapunov stability theory. When the nodes increase, this pinning method displays its ad-vantage in improving the efficiency of chaos control compared to the environment-based method (Chapter 4) which needs longer duration. Besides, the number of controlling nodes is easily fig-ured out by computing the eigenvalues of the sub-matrix rather than large-scale linear matrix in-equality. In other words, the aim of chaos control can be reached by selecting the nodes in the networks.Finally, the whole thesis is naturally concluded with the future work clarified.