电动机

Its thought is to change the model of the asynchronous motor through the coordinate, make it become direct current motor model, divided the electric current vector of the stator into according to the weight of two pieces of direct current with directional magnetic field of the rotor and controls, realize magnetism coherent and torque solve lotus root control , in the hope of the control result of the direct current reaching machine.

其思想就是将异步电动机的模型通过坐标变化，使之成直流电动机模型，将定子电流矢量分解为按转子磁场定向的两个直流分量并分别加以控制，从而实现磁通和转矩的解藕控制，以期达到直流电机的控制效果。

What this paper finished mainly work as follows: Five-phase hybrid step motor driver system with fixed-chopping frequency and constant total current driving is fully described. Mathematical model of the system, included the current control circuit, power driving circuit and five-phase hybrid stepping motor is established. The steady modeling of the system is established and studied. Based on the steady modeling of the system, dynamic modeling of the system is studied and single step response characteristic is constructed with MATLAB/Simulink. The simulation results, which is certified by the theory analysis, coincide with the theory analysis.

本文主要完成的工作包括几个方面：对五相混合式步进电动机恒频斩波恒总流驱动系统进行了完整的描述；建立了包括电流控制电路、功率驱动电路以及五相混合式步进电动机在内的恒频斩波恒总流驱动系统的完整的数学模型；基于MATLAB/Simulink建立了恒频斩波恒总流驱动系统稳态仿真模型，并进行了仿真；在建立其稳态仿真模型的基础上，对动态模型进行研究，并借助于MATLAB/Simulink工具建立了恒频斩波恒总流驱动系统单步响应特性的仿真模型并对其单步响应特性进行了仿真研究，仿真结果与理论分析相符。

First, the dissertation summarizes the properties, developing state and application fields of BLDCM, then its fundmental structure; operation principle and control strategy is also presented. On the base of roundly analyzing all kinds of the drive motor in electromotion type railway switch, BLDCM is proposed to replace the formerly traditional DC motor in railway switch. Second, the whole design scheme and key technology of control system is put forward based on analyse of the technical parameters and requirements.

首先，论文介绍了无刷直流电动机的特点、发展和应用概况，分析了稀土永磁无刷直流电机系统的基本构成、工作原理和控制方法；在对目前各种电动转辙机驱动电机分析的基础上，提出将稀土永磁无刷直流电机用于铁路转辙机，以替换原有的串励有刷直流电动机。

In this paper, we present a frequency conversion electromotor system organized by voltage vector transducer and induction-motor.

本文研究了用电压矢量变频器和感应电动机构成的变频电动机系统。

Beginning from the electromotor common control theory, this paper discuss basic concept of AC motor with vector control.

以电动机统一控制理论为切入点，论述了交流电动机矢量控制基本概念。

Alternating current electromotor is one of important chapters in the teaching of"electrotechnics"and"television".

三相交流同步和异步电动机都是靠其定子旋转磁场来工作的，故旋转磁场是交流电动机的基础和关键。

Firstly, according to electromagnetic field theory, the 2-dimensional (2-D) mathematical model of a three phase squirrel-cage Y802-2 induction motor is developed. Then general equations can be deduced from finite element discrete and functional analysis. The motor's 2D solving region of electromagnetic field is given based on the boundary conditions and assumption conditions of the squirrel-cage induction motor. Through finite element mothod and inner–outer convergence method, magnetic field distributions and magnetic forces of bars can be calculated in following rotor conditions: health rotor, one single broken bar, two adjacent broken bars, two broken bars with one good interval, two broken bars with two good interval and four adjacent broken bars.

本文首先根据电磁场理论建立Y802-2型三相笼型感应电动机二维电磁场的数学模型，并对其进行了有限元离散以及泛函分析，推导出总体方程；在基本假设和边界条件基础上，给出笼型感应电动机二维电磁场的求解区域，然后应用有限元并结合内外双收敛方法，对样机稳态运行进行数值计算，得出电机在转子完好、一根导条断裂、连续两根导条断裂、间隔一根两根导条断裂、间隔两根两根导条断裂及连续四根导条断裂六种情况下的磁场分布和导条所受电磁力的变化情况。

In order to take account of the effect of magnet field harmonic,the phase winding loop model is usually used in square wave propulsive motor.

为了充分考虑磁场各次谐波的作用，方波推进电动机一般采用相绕组回路的数学模型，模型中绕组参数的测量和计算较为复杂，其中带阻尼绕组的多相永磁同步推进电动机的绕组电感测量和计算尤为困难。

The validity of the method is demonstrated by comparison with results obtained from tests on a practical drive system. The influence of damper winding on performances of self-controlled synchronous motor, especially on commutation process and commutation limit, are analyzed in detail. It is shown that damper winding has little effect on increasing overload capability. The influences of field winding on torque, commutation process and overload capability are analyzed also.

然后在此基础上，分析了阻尼绕组和励磁绕组对自控式同步电动机性能的影响，包括对电磁转矩、换流过程和过载能力的影响，重点分析了阻尼绕组对换流过程和换流极限的影响，讨论了阻尼绕组在自控式同步电动机中的作用，得出阻尼绕组对提高过载能力作用不大的看法。

This process described the frequency changer - sensor - electric motor test system mathematical model, and in the platform which the microcomputer, the high speed sampling card, hypothesized instrument software constitutes, has realized to the frequency changer power supply electric motor test.

此次过程描述了变频器-传感器-电动机测试系统的数学模型，并在微机、高速采样卡、虚拟仪器软件构成的平台上，实现了对变频器供电的电动机的测试。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。