【作者】 张丽秀；

【导师】 吴玉厚；

【作者基本信息】 大连理工大学 ， 机械制造及其自动化， 2012， 博士

【摘要】 电主轴单元是高速数控机床的关键功能部件,其运行特性决定机床的加工质量。电主轴的运行过程中存在的主要问题为由电磁损耗导致的温升及由磁场相互作用导致的振动。特别是由于电主轴采用变频器供电,电源电压(电流)波形为含有谐波的非正弦波,产生一系列的谐波效应,影响了电主轴的性能及使用寿命,因此研究非正弦供电下电主轴电磁特性是必要的；此外,电主轴的运行特性与控制系统密切相关,高性能电主轴对控制系统提出了更高的要求,控制系统性能的改善是当务之急。本文在深入研究电主轴电磁损耗、电磁振动、直接转矩控制策略的基础上,研究改善其电磁特性及控制策略的方法,开展的相关研究工作及结论概括如下：采用有限元分析的方法,研究了电源形式、载荷及转轴材料对电磁损耗的影响,揭示了电磁损耗的本质。针对高速电主轴难以进行加载实验的问题,提出了连接式电主轴特性测试方法并实现电主轴加载。采用该装置进一步实验研究了载荷及转轴材料对电主轴损耗及效率的影响。综合仿真及实验结果,认为将陶瓷材料应用于电主轴转轴,将有效减小电磁损耗。采用仿真分析及实验研究相结合的方法,研究了电源形式、载荷、转轴材料对电磁振动的影响,揭示了电磁振动的本质。通过对陶瓷电主轴与金属电主轴振动性能的对比,得出了相同结构参数条件下,陶瓷电主轴振动小于金属电主轴的结果。通过仿真及实验进一步研究了气隙大小及气隙偏心对陶瓷电主轴性能的影响。指出气隙越大,电主轴振动及噪声越小,但气隙增大将减小电主轴效率。气隙偏心使电主轴产生单边磁拉力,陶瓷电主轴比金属电主轴具有更强的抵抗单边磁拉力作用下的变形能力。基于电主轴的动态数学模型及直接转矩控制原理,建立了电主轴直接转矩控制仿真模型,分析了定子电阻变化对直接转矩控制性能的影响；理论分析了影响定子电阻变化的主要因素；借鉴电机参数测试国家标准对电主轴定子电阻进行冷态及热态测量,分析定子电流、运行频率及电主轴温度对定子电阻的影响。提出了人工智能神经元网络(ANN)及案例推理(CBR)相结合的定子电阻混合智能辨识方法。建立了基于ANN-CBR的定子电阻辨识模型,通过辨识结果与实测结果对比表明该方法适合具有非线性特征的定子电阻辨识问题,辨识精度较高。论文通过对电主轴电磁特性及直接转矩控制策略的深入研究,提出了改善电主轴运行特性的有效方法。为新型材料在电主轴转轴上的应用提供了依据,同时也为混合智能方法在电主轴控制系统的应用奠定了理论基础。更多还原

【Abstract】 Motorized spindle cell is a key component of high-speed CNC machine tools and its operating characteristics determines the machining quality of the machine tools. The main problems of motorized spindle in running are the temperature rise caused by electromagnetic loss and the vibration of the interaction of the magnetic field. Moreover, the power of motorized spindle is supplied by inverter and its output voltage (current) is non-sinusoidal with harmonics, resulting in a series of harmonic effects. The harmonic effects influence the performance and service life of the motorized spindle. Therefore, it is necessary to study the electromagnetic characteristics of the motorized spindle under inverter supply. In addition, the operation characteristics of the motorized spindle relate closely to the control system and high-performance electric spindle needs to match the high performance control system. So it is necessary to improve the performance of the control system. On the basis of the deep analysis of the electromagnetic loss, electromagnetic vibration and direct torque control strategy, the methods to improve the electromagnetic characteristics and the control strategy of the motorized spindle are studied in this paper. The main works and conclusions are summarized as follows:The influence of the power form and load and shaft materials on the electromagnetic loss is researched based on the finite element in order to reveal the essence of electromagnetic loss. Loading and measuring the load applied on a high speed motorized spindle in the non-machining state is an important issue in performance evaluation of high speed motorized spindle. A new method is developed through connection mode to make the loading possible in the experiment. The influence of the load and shaft materials on the efficiency and electromagnetic loss of the motorized spindle is further researched using that device. The simulation and experimental results show that applying the ceramic material to the shaft of the motorized spindle may reduce the electromagnetic loss effectively.The influence of the power form, load and shaft materials on the electromagnetic vibration is researched by the simulation and experiments in order to reveal the essence of electromagnetic vibration. The results show that the vibration speed of ceramic motorized spindle is smaller than the metal motorized spindle through the comparison of two kinds of motorized spindle under the same structural parameters. The influence of length and eccentricity of air-gap on the performance of the ceramic motorized spindle is further researched through simulation and experiment. It is pointed out that the bigger the air gap is, the smaller the vibration and noise of motorized spindle are. But at the same time, the efficiency of motorized spindle is reduced. Air-gap eccentricity results in unilateral magnetic force in motorized spindle and the deformation of the ceramic motorized spindle is smaller than the metal motorized spindle under unilateral magnetic force.A direct torque control spindle simulation model is established based on dynamic model of the motorized spindle and direct torque control principle, in order to analyze the influence of variation of stator resistance on performance of direct torque control. The main factors of influence the variation of stator resistance is analyzed in theory. The stator resistance under cold and hot conditions is measured by means of reference on the national test standards for motor parameter and the influence of stator current, operating frequency and temperature on the stator resistance is analyzed.A hybrid intelligent stator resistance identification strategy is proposed based on artificial neural network (ANN) and Case-Based Reasoning (CBR). A model for the stator resistance identification is established based on ANN-CBR. By comparing the recognition results and experimental results, it shows that the method fits for non-linear characteristics of the stator resistance identification problem with higher recognition accuracy.This thesis proposes the effective method to improve the running characteristics of motorized spindle based on study of the electromagnetic characteristics and direct torque control strategy. A basis is provided for the application of new material on motorized spindle and the theoretical foundation is established for the application of hybrid intelligent method in control system of motorized spindle.更多还原