Analysis Of Magnetic Force And Stator Vibration Modals For Large And Middle Size Induction Motor

The vibration and noise of electrical machine is the important symbol for evaluating the electrical machinery quality. Along with the improvement of design and manufacture level, the modern electric machine design is facing the big electric current, high magnetic flux direction. While the high magnetic flux, big electric current obtain the application as well as structure dexterous, the electromagnetic noise of electrical machinery gets bigger day by day. There is the important application value for the vibration research of the electrical machinery. The electrical machine vibration and the noise research is extremely complex, it involves the electromagnet analysis, the energy conversion, the mechanical vibrations, the physical acoustics, electronics and mathematics and so on many disciplines. The research centered on the vibration question of the YKK500-4 asynchronous machines. The vibration excitation and structure vibration characteristic of asynchronous machine are analyzed.Firstly, the electromagnetic radial force of asynchronous machine is analyzed based on the traditional analysis method: the magnetic potential and the magnetic conductance law. The distribution of air gap magnetic-flux density and the radial force wave are analyzed with these methods either. Afterwards this article obtains the structure computation double ring stator structural model through mechanical and electrical analogy. Then the influence of different rotor slots number of the YKK500-4 electrical machine is calculated preliminarily.Then, the electromagnetic force calculation methods based on magnetic field analysis by finite element method (FEM) are introduced. At the same time, the Maxwell stress tensor and virtual work methods by using ANSYS software are also illuminated. The asynchronous machine radial force wave is analyzed with the aid of the electromagnetic force computational method. The cogging influence may be considered by using finiteelement method. That is more sufficient then the analysis law. Through the comparison of the different rotor slots number, the influence of the radial force wave of different rotor slots number is studied. Thus it lays the foundation to the electrical machinery structure vibration influence for the further studying of the radial force.Finally, the asynchronous machine stator structure vibration characteristic is studied. The energy method may be used for calculating the natural frequency. In this article the finite element analysis software ANSYS is taken as tools, and the modals are picked up by Lanczos law. The analysis compares the different of 2D and the 3D model and the winding function. Then the stator model based on the real asynchronous machine is established. The natural frequency of several kinds of 3D stator models is studied. Moreover, the influence of the electrical machinery stator design parameter (for example stator outer diameter, axial length and so on) is also considered.