| The bearingless motors have improved the composition structure of the traditional motor, created a new era of "bearingless" in high-speed motor. Among them,the bearingless induction motor(BIM) not only has all the advantages of magnetic bearings and bearingless motor, but also can realize driving and self suspension function. Because the BIM has the advantages of no-friction, no-wear, no-lubrication, operation at high/ultra-high speed, simple structure, symmetrical air-gap, and low cost. In the field of high speed machine tools, flywheel energy storage, aerospace and other fields of science,BIM has broad prospects. At present, the traditional double-winding structure has been studied at home and abroad, this structure has a larger difficulty production and double-winding overlap in the stator can lead to short circuit and other defects. Therefore, it is great value to design the stator winding of BIM into the single-winding form. With the help of the National Natural Science Foundation of China(51475214, 61104016), this paper studies the structure and principle, the finite element model and mathematical model, control strategy and digital control of the single-winding BIM. The specific contents are as follows:Firstly, on the basis of introducing the principle of the traditional double-winding structure, the model of single-winding structure is established. Based on the analysis of single-winding structure, working principle and generation principle of radial suspension force, the mathematical model of single-winding BIM is deduced.Secondly, in the Ansoft software, the motor model is established, and the 2D, 3D structure and winding mode of the motor are given. Based on the theory of electromagnetism, the two-fundamental wave research method on radial suspension force is presented and the mathematical model of radial suspension force is deduced. In Ansoft, the finite element value of the radial suspension force is compared with the variable stator current. The mathematical model value of radial suspension force based on two-fundamental wave method is analyzed. The consistent conclusion of the mathematical model value and the finite element value is obtained. The foundation of stable suspension control is established.Thirdly, based on the air-gap field oriented control, combined with the control method of current superposition, the control system of single-winding BIM is constructed. In MATLAB/Simulink, modeling and simulation are carried out. The results show that the control method of single-winding BIM can realize the stable suspension operation.Finally, using the DSP chip, combining with the characteristics of single winding BIM, the digital control platform of single winding BIM is built. The suspension characteristic experiment research is carried out and the experimental waveform is analyzed in detail. The experimental results show that the digital control platform has better performance in suspension and static performance. |
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