The Research And Practice On Key Techniques Of High Speed Switched Reluctance Machine

With the development of the science and technology, there is urgent need for high speed motor in aerospace, energy, precision manufacturing and many other fields. The increase of motor speed is conductive to improve the electrical power density, reduce the size and the weight of the equipment. As a result, high speed / super high speed motor have received high popularity in the field of military and civilian applications, and it have been the hot topic in the international electrical field at present.Switched reluctance machine (SRM) is a new type of adjustable-speed motor, based on the development of power electronic and control technology in recent years. It has been employed in variable speed industrial applications due to their simple and rugged structure, low cost, and high reliability. The rotor has no windings, magnets, or squirrel-cage winding, but is constructed from a stack of salient-pole laminations. This structure can withstand high mechanical stress, especially fit for the high speed requirements and adapt to the harsh environment. Therefore, SRM is considered the motor which has the advantage in the field of aerospace, high speed manufacturing of high speed / super high speed applications.This dissertation focuses on basic research for the theory and application of high speed SRM system, in order to lay the foundation for the high speed SRM system design and engineering application. Based on the extensive and in-depth understanding of the outcomes in the past, some breakthrough have been made toward the multi-parameter integrated design, main circuit of power converter, application specific integrated circuit, and other core technology. At the mean time, some systematic study have been conducted toward the mechanism, prototype design, experiment and engineering applications, and a experimental platform of the high speed SRM has been built.In terms of the operational features of the high speed SRM, a multi-parameter integrated design method has been developed in this paper, on the basis of regular electromagnetic design process and the finite element calculation of multi-physics field, including the electromagnetic, core loss, stress, rotor vibration, etc. The method comprises of electromagnetic design, loss calculation, the structural stress analysis, rotor dynamic analysis. At the same time, three high speed SRM experimental prototypes were successfully developed, laying the theoretical foundation for SRM prototype designing. Taking into account the need for the experiment and research of high speed prototype, much theoretical and experimental research have been conducted toward key techniques such as electromagnetic performance optimization, rotor structure stress and dynamic performance analysis, iron and windage loss calculation, etc. In the dissertation, the advantages and disadvantages of some typical main circuit of SRM power converter, such as the asymmetrical half-bridge, split-phase main circuit is analyzed, and the influence to the SRM commutation performance brought by the topology of the typical power converter have also been discussed. On the basis of the topology of the conventional double-switch asymmetrical half-bridge main circuit, a three-switch asymmetrical half-bridge topology is proposed which could enhance the motor commutation performance. Meanwhile, the simulation analysis and comparison experiment was conducted between the double-switch and the three-switch main circuit based on a experiment prototype.An application specific integrated circuit (ASIC) of SRM named SR3P10K07A was designed, which is the first integrated circuit for the SRM control in our country. The specific design process and the detailed information of the implementation algorithms of every function block have been introduced in this paper. Then the logic function of this chip has been verified on the basis of the hard-ware circuit. Based on the SR3P10K07A, a common set of SRM digital controller was designed and developed in this dissertation, the successful application to several high speed SRM have proved the feasibility of this chip.In addition, the experiment research and engineering application was initiated toward three high speed SRM prototypes in this dissertation. The experiment result shows the maximum speed of the prototypeâ… achieve 136,000r/min. As a high speed prime motor, the prototypeâ… have acquired the successful application in the air-bearing performance test platform developed by the Micro Engine Institute of NUAA. Meanwhile, a no-load experiment was made to conventional salient rotor and cylindrical composite salient rotor respectively based on the prototypeâ…¡, and the comparison of the windage loss was made toward this two different rotor structure. The prototypeâ…¢have a successful application in the high speed computerized numerical control engraving machine NRT40M produced by the CHANGZHOU NEW ROUTER NC MACHINERY CO., LTD.