直流的

Based on the formula of attractive force the functional relationships among attractive force,coil current and speed of armature are acquired,and the simulation of dynamic characteristics is given.

随后分析了影响电磁铁的快速性和可靠性的因素，明确了可用于评价快速性和可靠性的重要参数，为理解直流电磁铁的动特性并提高直流电磁铁的设计水平提供了一种思路。

The thesis first probably explains BrushLess Direct Current Motor, and discusses the related control methods, explains the background and Meaning of back electromotive force which is used in the thesis.

本文首先对无刷直流电机进行了概述，并对其相关控制方法进行了讨论，说明本文所采用反电动势法的背景和意义；接着论述了无刷直流电机基本组成环节、基本工作原理、运行特性和传递函数，然后是详述本文研究的重点：基于反电动势法的MATLAB调速系统的仿真以及基于反电动势法的DSP控制系统的实现。

The thesis first probably explains BrushLess Direct Current Motor, and discusses the related control methods, explains the background and Meaning of back electromotive force which is used in the thesis.Then the thesis expounds the basic component parts,the basic running principle,the running characteristic and transfer function of the BLDCM.And then the thesis detailedly dissertates its research pivot: the simulation of BLDCM system in MATLAB based on the method of Back-EMF and the control system of Digital Signal Processor based on the method of Back-EMF.

本文首先对无刷直流电机进行了概述，并对其相关控制方法进行了讨论，说明本文所采用反电动势法的背景和意义；接着论述了无刷直流电机基本组成环节、基本工作原理、运行特性和传递函数，然后是详述本文研究的重点：基于反电动势法的MATLAB调速系统的仿真以及基于反电动势法的DSP控制系统的实现。

It is extensively used for different occasions that require DC power supply, including electrolytic chemistry, transmission, traction, electrostatic precipitation, electroplating and DC transmission etc.

整流变压器是指把电力网的三相正弦交流电压变换为所需要的交流整流电源的电压和相数的电源变压器，它广泛应用于点解化学、传动、牵引、静电除尘、电镀、直流输电等需要提供直流电源的场合。

In the present paper,the goal applies in the development in the mixed style battery cocurrent of motor driver design in the electrically operated bicycle,the use lead-acid battery and the LiFePO4 battery takes the main actuation power to originate,the iron phosphate lithium battery has the life to be long,the electric discharge power is big and the transformation power suits the high electric current product good the characteristic;The lead-acid battery is in a market condition the quite mature battery product has the high security in the thermostable characteristic,and designs a driving circuit to actuate the cocurrent to have brushes the motor to lead the bicycle advance,comes in the enfilade non-ascent road section use LiFePO4 battery as the actuation electric power to originate,in had the ascent road section use lead-acid battery to come as the actuation electric power to originate, has promoted bicycle's endurance and reduces accumulator cell's energy loss.

本论文中，目的在研制应用於混合式电池於电动自行车之直流马达驱动器设计，使用铅酸电池与磷酸铁锂电池来作为主要驱动动力来源，磷酸铁锂电池具有寿命长、放电功率大及转换功率佳适合高电流产品的特点；铅酸电池为一市面上相当成熟的电池产品具有高度的安全性於耐高温的特性，并设计一驱动电路来驱动直流有刷马达来带动自行车前进，於直路无斜度路段使用磷酸铁锂电池来作为驱动电力来源，於有斜度路段使用铅酸电池来作为驱动电力来源，提升了自行车的续航力和降低蓄电池的能量损耗。

This thesis calculates emphases the excitor circult of AC excitor .but the calculate of excitor circult must solve two problem: how to caculate the output AC phasic potential, phasic electric current and the capacity of AC excitor basing on the main generator direct current excitating voltage and direct current excitation current ;how to caculate the armature feedback, power factor and required ampere-turn of AC exciter.

本文重点对交流励磁机的磁路进行计算，但磁路计算先要解决两个问题：如何根据主发电机给定的直流励磁电压和直流励磁电流计算出交流励磁机的输出交流相电势，相电流及交流励磁机容量；如何计算交流励磁机的电枢反应，功率因数及其所需的安匝数。

Then introduce the principle of work and the construction characteristic. This thesis calculates emphases the excitor circult of AC excitor .but the calculate of excitor circult must solve two problem: how to caculate the output AC phasic potential, phasic electric current and the capacity of AC excitor basing on the main generator direct current excitating voltage and direct current excitation current ;how to caculate the armature feedback, power factor and required ampere-turn of AC exciter.

本文重点对交流励磁机的磁路进行计算，但磁路计算先要解决两个问题：如何根据主发电机给定的直流励磁电压和直流励磁电流计算出交流励磁机的输出交流相电势，相电流及交流励磁机容量；如何计算交流励磁机的电枢反应，功率因数及其所需的安匝数。

Experimental results show that the error between measurement vibration signal and its theory value is only 2.4%.

实验结果表明：用直流电路法测量得到的声波信号与其理论计算值之间误差仅为2.4%，证明了直流电路法的适用性，解决了目前Lamb波器件的功能材料层的制作工艺均与传统集成电路工艺不兼容的问题。

A new active filter concept is proposed in this part, which is DC side active power filer technology.

对同样的整流桥负载进行谐波补偿，论文所提出的三相直流侧有源电力滤波与传统的三相交流侧有源电力滤波器相比，三相直流侧APF具有更小的补偿容量、开关应力，以及更好的补偿效果。

A key point in Short Time Fourier Transform is the choice of window function. Although rectangle window is regarded as the first choice because it's featured by integral harmonic to filter signals and by DC component, decaying DC component and frequency shift of signals cause great error to rectangle window STFT. In addition, transient signals contain rich information of faults, but the fixed time window of STFT fail to collect these information.

STFT 算法关键问题之一是窗函数的选择，矩形窗以滤除信号整数次谐波和直流分量的特点自然称为首选窗，但衰减直流分量和信号的频率偏移对矩形窗 STFT 造成了很大误差；其次，暂态信号中含有丰富的故障信息，傅立叶变换固定的频窗忽略了这些特征信息。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。