Application And Research On Wavelet Analysis In Linear Motor Control System

Linear motor has a special phenomenon that is end effect. It is influence control system performance of linear motor. In this thesis presents an improvement method of direct thrust control system performance, which based on study and analysis of choice function and algorithm of Wavelet analysis. Observation accuracy of flux linkage influences the performances of direct thrust control system, specially the low speed performance. Wavelet algorithm is used to increase observation accuracy of flux linkage, and the purpose of system improvement has reached.Linear motor is a novel motor, because it can make electric energy transferred into linear motion, which doesn't need any intermediate conversion, and then it has widely application and development areas. But linear motor structure has a specific phenomenon that is end effect, which is one of major factor influence the linear motor control system performance. Its direct appearance is periodic and non-stable fluctuation of thrust. Therefore, it is offered a theory premise for the linear motor widely application that weakening the influence of the end effect. In direct thrust control system, flux linkage observation accuracy influences the thrust of linear motor. Therefore, it is offered a theory premises that increase the observation accuracy of flux linkage.Wavelet analysis is a novel mathematical theory and method proposed in 1980s. It is as regarded as a breakthrough of Fourier analysis because it has many wonderful characteristics. It is benefit for processing the non-stable signal, because wavelet theory has the characteristic of the time frequency location characteristic and multi-resolution analysis. Therefore, Wavelet analysis is used in direct thrust control system of linear motor in this thesis. End effect influence analysis is based on multi-resolution analysis of Wavelet analysis, and a compensation method for performance influence of linear motor thrust has presented. Second, Wavelet analysis isused in primary resistance identification of direct thrust control system. The observation of flux linkage is improved by accurate identification of primary resistance, and direct thrust control performance at low speeds is further improved. Finally, the feasibility of method and improvement of system performance has been proved by simulation.