Quantitative Analysis For Space Harmonic Of Fractional Slot Permanent Magnet Motor And Research On Torque Ripple Suppression

With the wide application of new energy in recent years, the application prospect of permanent magnet motor will be more extensive. The torque ripple of permanent magnet motor is a key index for high performance speed control and servo system of the motor, As a general rule, the torque ripple for the permanent magnet motor is not greater than3%. Therefore, the research on torque ripple suppression for permanent magnet motor has very important significance.In this paper, according to the principle of permanent magnet motor cogging force generation, reverse research methods are put forward to research influence of the motor structure on the suppression of the tooth harmonic. It is calculated by the finite element method. In this article, first of all, Finite-element method is adopted to calculate cogging torque of the fractional slot permanent magnet motor, and the every harmonic of the power spectrum is got by Fourier transform and every harmonic is normalized processing. The harmonic influence of each structural parameter on the fractional slot motor can be achieved by changing four structural parameters in turn. The four structural parameters are width of slot opening, air-gap size, pole arc coefficient and thickness of magnet. THD is imported to analyze the influence of every structural parameter on the higher harmonics in fractional slot permanent motors quantitatively.a set of optimal structure parameters combination is got by combined with finite element analysis and THD analysis. In this article, the scheme, combines theory analysis with experiment validation is adopted to study suppression method of fractional slot permanent magnet motor torque ripple. In this paper, the research content:1. Roots and the effects of the cogging harmonic is analyzed for fractional slot permanent magnet motor, and inhibition of the strategy. By finite element software fractional slot permanent magnet motor calculation model and the calculation of the motor model of electromagnetic field is established. The cogging torque of permanent magnet motor value and FFT spectrum analysis is also demonstrated here.2. By Fourier transform of power spectrum of each component, based on spectrum analysis of each component, four kinds of structure parameters of the motor torque ripple is changed which affect the tooth harmonic, we get each tooth harmonic effects of structure parameters on the motor. Then combine with the quantitative analysis of harmonic distortion rate, we can get impact of higher harmonic of each structure parameters. A set of optimal structure parameters which combined four structure parameters is demonstrated. Optimize the structure of ontology of motor. Minimize the torque ripple of motor harmonic through the quantitative analysis of motor ontology structure.3. Through theoretical analysis and simulation data, obtain a set of optimal multidimensional structure parameters of the motor through establishment of orthogonal table the orthogonal analysis method can obtain the optimal structure parameters which effectively inhibits the cogging force of the harmonic. Performance of permanent magnet motor is demonstrated by means of experimental verification and the reliability of the model of permanent magnet motor is verified here.