Study On Method Of Chaotic Control For Permanent Magnet Synchronous Motors

Permanent magnet synchronous motors (PMSMs) have superior features such as compact size, high torque/weight ratio, high torque/inertia ratio and absence of rotor losses, and advantages of higher efficiency compared with induction motors. With the development of electronic technology and control technology, the PMSMs are widely applied in high performance servosystem. Especially in rencent years, the conventional motors were superseded by PMSMs due the development of permanent-magnet material and control echnology. The foreground application is very optimistic. So it is important to sduty the permanent magnet synchronous motors.In this paper, the chaos fo PMSMs is investigated firstly. The study indicates that PMSMs are sensitive to the parameters, the chaotic phenomena will happen if the parameters fall into some area. Because the chaos is baneful to the PMSMs, we must restrain it for PMSMs. So the emphasis of this paper is studying the method of controlling chaos of PMSMs. Furthermore, the values of parameters of the PMSM model are not constant, but span some interval. The main reason is that the permanent magnetic-flux will vary with the temperature rise of permanent-magnet material and rotary inertia will vary with the attrition of the device, or modelling errors, measurement inaccuracy, and so on. The parameters uncertains will be considerd in our study. So we investigate the chaos and the control strategy for PMSMs with parameters uncertains.As for the study of the chaotic control strategy for PMSMs, the main results in this paper can be described as follows: (1) The impusive control strategy for PMSMs with fixed parameters si investigated firstly. Then the sufficient conditions of the robust stability are established by employing the method of Lyapunov functions. Then the impulsive controller is designed for PMSMs with uncertain parameters. After the uncertain matrixes which represent the variable system parameters are formulated through matrix analysis, the asymptotical/exponential stability criteria of fuzzy control are established. (2) The fuzzy control mathematics model is established, and the fuzzy controllers for PMSMs with fixed and uncertain parameters are designed respectively. (3) Based on the above study, the chaotic fuzzy impulsive control model is brought forward. The fuzzy impulsive controller which containing the merits of fuzzy and impulsive controller is designed. The stability of fuzzy impulsive control is investigated, and the asymptotical/exponential stability criteria of fuzzy impulsive control are established for PMSMs with fixed and uncertain parameters. Our results indicate that the fuzzy impulsive control is difficult with the increase of pulse spacing, the theoretical controller exists but the control cost will increase. So the fuzzy impulsive control is effective for small pulse spacing. The numerical simulations illustrate the affectivity of all the above control strategy.Otherwise, the disturbances exist in PMSMs due to the instability of voltage, concussion of running circumstance and so on. So the PMSMs with disturbances especially impulsive effects are investigated in the end of this paper. As the analysis of the above, the PMSMs with fixed parameters and uncertain parameters are considered. Firstly, the chaotic mathematics model is brought forward. Then the control rules are designed. And the asymptotical/exponential stability criteria for PMSMs with impulsive effects are established. Furthermore, the numerical simulations illustrate the affectivity of the above control strategy for PMSMs with impulsive effects.In a word, it is creative to apply the impulsive theory and fuzzy theory to PMSMs. The stability of PMSMs is investigated by the theory of impulsive differential equation, fuzzy control and Lyapunov function. It is important for the application and development of PMSMs.