Motor Vibration Suppression Studying Based On Fractional-order Control

Inhibition of motor vibration has been an important issue of concern, previously, the method of motor vibration suppression is mainly achieved by optimizing the device structure, increasing the damping materials or devices, etc, these methods are the main way for suppression of motor vibration, and can play a better role in inhibition, but sometimes also may increase the complexity of the system structure.Therefore, to the specific motor model and without increasing the complexity of the system structure, this paper mainly discusses how to improve the vibration suppression performance of AC motor from the perspective of the control law, and researches the application of fractional-order PIλDμcontroller in AC motor vibration suppression. In order to make fractional-order PIλDμcontroller better control the system, a method of parameters of fractional-order PIλDμcontroller is presented based on binary coding and improved Genetic Algorithm. The main research work of this dissertation is given as follows:1. Based on the basic Genetic Algorithm, the improvement of the basic Genetic Algorithm is successfully achieved through the improvement of the fitness function, genetic operators and the analysis and determination of gene frequency;2. Study of grade-tuning strategy. Focused on the objective function and weight determination, as well as the design of fitness function, a grade-adjusting method of parameters of fractional-order PIλDμcontroller is presented based on binary coding and improved Genetic Algorithm. To the specific motor model, this paper studied and analyzed experiment through the MATLAB simulation. Concrete operation process is as follows: (1)Firstly, parameters of integer-order PID controller are optimized by improved Genetic Algorithm and fixed; (2)And then an optimizing process is applied to the order of fractional-order PIλDμcontroller with improved GA; (3)Lastly, Three coefficients of fractional-order PIλDμcontroller are re-tuned, by fixing the integral and differential order;3. Study of the relationship of fractional-order controller parameters and controller performance. Through simulation, if (3) and (2) have a similar control effect, indicates that coefficients and orders of fractional-order PIλDμcontroller do not interact, further illustrates the hierarchical strategy for tuning the parameters of fractional-order PIλDμcontroller is valid. If (3) and (2) have a great difference control effect, indicates that coefficients and orders of fractional-order PIλDμcontroller are interactive, further illustrates a synchronous-tuning for five parameters may be made more stable and reliable control effect for fractional-order PIλDμcontroller;4. Graded-tuning simulation results also show that: compared with the fixed coefficient and fixed order of fractional-order PIλDμcontroller, the control effect has differences. In two classification tunning, proportional, integral and differential coefficient of controller have two tuning results, three coefficients of controller have a larger difference between the results of the two tuning by comparing. Coefficients of fractional-order PIλDμcontroller is mutual influence. So a synchronous-tuning method of based on binary coding and improved Genetic Algorithm, which is applied for the optimization of the five parameters of fractional-order PIλDμcontroller, including orders of fractional calculus.