查询词典 magnetic flux

Faraday's law is that when the flux in the conductor loop changes, it produces electromotive force in the conductor loop, and obeys to contour integral law , Maxwell Curl Theory is that when the magnetic intensity of a certain point in ether space changes, there produces electric field at that point in ether space, which is the field mutual production theory of "electric field produces magnetic field and magnetic field produces electric field" in the free space which everybody is familiar with, and it obeys differential law , Lorentz magnetic force is that when metal electrons cut magnetic lines, metal electrons forced by move along the conductor to form inductive current, in fact, it doesn't matter whether coil moves or magnet moves, only if there exists relative motion between magnetic field and conductor, metal electrons must cut magnetic lines, which is,"coil stills while magnet moves to the left" and "magnet stills while coil moves to the right" these two situations are the same, which both belong to metal electrons having cut magnetic lines.

法拉第定律指导体环路里的磁通量发生变化时，在导体环路上产生电动势，而且服从围线积分律；麦克斯韦旋度理论指以太空间某点的磁场强度发生变化时，在以太空间的该点产生电场，即大家熟知的自由空间里"电场生磁场与磁场生电场"之互生场理论，而且服从微分律；洛伦兹磁力指金属电子切割磁力线时，金属电子受力沿着导体漂移而形成感应电流，其实，无论线圈运动或是磁铁运动，只要磁场与导体存在相对运动，则金属电子必然切割磁力线，即，"线圈静止而磁铁向左运动"与"磁铁静止而线圈向右运动"这两种情况是一样的，都属于金属电子切割了磁力线。

According to the demand of high magnetic field power supply, reference is increased with a set ramp rate and stops at a set stable value, so reference system is composed of digital setting and digit to analog converting circuit. But the stability of reference is mostly guaranteed by the performance of D/A circuit, so D/A circuit is particularly studied in reference system. The scheme of D/A circuit, the selection of DAC and its voltage reference, hardware anti-jamming design and PCB design are discussed in detail, and software of remote control and PLC are discussed in brief. Zero-flux DC current transformer well satisfies the demands of the high stability of Load current detection unit, so the principle of zero-flux DC current transformer is analyzed; in the mean time a project which detects the long term stability is designed. During 8 hours, analog signal which is detected with high precision digit multimeter is recorded in computer at 1HZ frequency by GPIB communication. The drift error source and related parameters are explained in the compare-amplify part. Detailed subtraction circuit is designed; also amplifier chip and periphery components are selected and verified according to the theory of error analysis.

根据强磁场电源的需求，参考源应按照软件设定的斜率逐渐上升到设定稳态值，则参考源系统应由数字给定和数模转换电路两大部分组成，而参考源的稳定度主要依靠完成数模转换功能的模拟电路的性能来保证，因此本文对参考源系统的研究以数模转换电路为重点，分别从电路方案的确定、数模转换芯片及其基准电压源的选取和验证、电路板硬件抗干扰和PCB设计几方面进行了论述，然后对数字给定部分的远控组态和PLC程序设计作了简要介绍；采用零磁通原理的直流电流转换器很好地满足了对负载电流检测单元高稳定度的需求，本文详细分析了零磁通检测的原理，并在选定此种类型电流转换器的基础上设计了一套检测长期稳定度的方案，8小时内以1秒为采样周期，通过计算机Labview程序和高精度数字电压表的GPIB通讯，将被高精度数字电压表数字化后的模拟信号采样值连续记录至计算机中；比较放大环节简要阐述了漂移产生的原因和相关参数指标，确定了具体的减法电路形式，并根据误差分析理论对运算放大器和外围元器件进行了选取和验证。

With experience gained from the Finite Element method, a quasi-linear model based on the Magnetic Equivalent Circuit method has been used to obtain the static torque of the motor. Three types of magnetic tubes are employed in the model, and through the exchange principle of magnetic lines of force and magnetic equipotential line, the tube in which the flux distribution is non-uniform is applied to the model.

通过分析电机二维磁场分布和考虑电机特殊的电磁结构，提出了用三种磁通管单元来近似磁场分布，并借用磁力线和等磁位线互换的方法，将磁力线分布不均匀的磁通管引入到分析模型中，有效的处理了平动式啮合电动机中的磁场分布不均匀和磁路局部饱和，使分析模型得到简化并兼顾了求解精度。

ABSTRACT Aiming at problems of trans-vector controller in a vehicle-carried induction motor such as variable rotor and stator resistance following motor temperature, and their inductance varying with flux saturation degrees. Firstly, CSI and VSI are introduced, for CSI, it can hold the advantages both FOC and DTC using stator flux directional, PI parameter and simulation are also introduced. Secondly, equations of IM in the synchronous rotary frame and its static counterpart, as figuring in the saturation condition of magnetic field, are dealt in this paper and the simulation results are presented. Thereafter, the parameter designing of PI trans-vector controller is processed, which features the non-linear model. In practical realization, as neglecting the dynamical change of motor inductance, this paper employs online modification of inductance parameters, according to the flux saturation, then transforms the non-linear equations into linear ones, and so compacts the structure of controller. Thirdly, in view of the maximum torque output is extraordinary requisite when Electrical Vehicle start up, accelerate, and overtake, this paper issues the maximum torque when both inverter and battery capacity is corporeally definite. Fourthly, on-line differentiating and analyzing both rotor's time constants and its flux by using the expanding order reduction and discrete Kalman filter equation are fathomed, in order to realize high-performance trans-vector algorithm, and also the simulation results are presented. Fifthly, the close-loop regenerative brake system, when the EV's torque is set constant, is deduced; at the same time, unification of electric drive model and brake model is executed. Combined with maximum charge current demands, the mathematical model for online yielding torque as a demand.

本论文针对车载异步电机在矢量控制器所遇到的问题：定转子电阻随温度变化及随电机饱和程度变化的转子电感及定子电感而影响电机调速性能提出一套完整的解决方案：分析了电流型逆变器和电压型逆变器在实现矢量控制时控制器参数的计算，分析出对于电流型逆变器在采用定子磁场定向时，其性能同时具有矢量控制和直接转矩控制两者的优势，并对电压型逆变器在转子磁场定向下的模型进行了仿真研究；建立异步电机非线性模型，推导出考虑磁饱和时异步电机在同步旋转坐标系及静止坐标系下的方程，并做出了仿真结果，建立异步电机在非线性模型下的矢量控制调节器的PI参数设计，在实际应用中，若忽略电机电感的动态变化，可以根据当前的磁路饱和状态而在线修正电感参数，从而将非线性方程线性化，降低控制器的复杂度；考虑到电动汽车在起动和加速超车时需要电机有最大转矩输出，本文讨论在逆变器容量一定和电池供电能力有限的情况下电机最大转矩输出问题；推导了异步电机扩展降阶、离散卡尔曼滤波方程在线辨识转子时间常数和转子磁通，用于实现高性能的矢量控制算法，并给出了仿真结果；推导出了电动汽车恒转矩给定的闭环回馈制动系统，实现了电动控制模型和制动模型的统一，而且结合铅酸电池最大充电电流的要求，为制动转矩在线给定建立了数学模型；设计了基于双DSP系统的高性能矢量控制器软硬件框图，并以大量实验数据说明矢量控制在电动汽车应用的实际应用状况。

According to graph 4 experiment, although the flux in closed loop does not change, but there is inductive current, this is because the metal electrons of segment cut the magnetic lines, and it forms current under Lorentz magnetic force.

对于图4实验，尽管闭合回路内的磁通量没有变化，却有感应电流，这是因为段的金属电子切割了磁力线，在洛伦兹磁力的作用下形成了电流。

The research results have shown that the configuration of the magnetic bearing reduces overall system size, and has high efficiency. The axial and radial suspension forces have great linearity. The symmetrical characteristic strenuously, and movement of every degree of freedom around balanceable position has no coupling and the control flux of every degree of freedom is independent. It is beneficial to simplify and design the controller and the circuit power amplifier. The magnetic bearings operate stably with decentralized PID controllers.

研究结果表明：这种磁轴承结构合理紧凑，效率高；磁轴承轴向、径向悬浮力具有较好的线性和对称性，有利于控制器及功放电路的简化与设计，并获得良好的拉制性能；各自由度运动和磁路几乎没有耦合，采用分散独立的PID控制器实现了磁轴承的稳定工作。

The paper also discusses the geometric sizes of magnetic path and the choice of magnetic materials,and contrasts the test results from the magnetic field flux density of two kinds of magnetic path and har...

通过对比两种磁路结构的检波器，讨论了磁路的几何尺寸和磁性材料的选用，并比较了这两种磁路的磁通密度及谐波失真的测试结果，说明了在检波器磁路设计中，均匀磁场可以降低输出信号中的谐波失真

In this paper,the magnetic suspension applied characteristics of Rare earth Permanent magnet material in the vibration isolating system are studied,and the method with which spatial flux density and magnetic force is calculated quantitatively is presented.

对稀土永磁材料在隔振系统的磁悬浮应用特性作了研究，给出了永磁系统空间磁密及磁力定量计算的方法，设计了一种新型磁悬浮式隔振装置，在运用试验及应用人工神经网络的方法对其良好悬浮特性和非线性刚度特性进行了综合分析的基础上，引入实验修正系数完善了理论模型，为磁悬浮隔振器的设计提供了理论依

We have made detailed studies of the influence of heat flux from the magnetosphere and ion flux along the magnetic field line of force on the morphology of the ionosphere. The validation of our ionospheric model is further verified. We contend to use radar data to specify the upper boundary condition in the simulation of the high-latitude ionosphere.

详细研究了磁层热流、离子沿磁力线的通量对极区电离层形态的影响，从另一角度证明了目前已建立的电离层模型的有效性，建议用雷达数据作为模型顶部边界条件开展电离层内部物理过程研究。

The method includes the following steps: depositing a non-magnetic layer (3) of sufficient thickness; anisotropically etching the non-magnetic layer to form a steep wall of suitable dimensions at the required position of a flux guide; depositing a magnetic material to form a magnetic layer (9) on the wall in such a manner that the magnetic layer has a thickness corresponding to the required track width; removing undesired deposits of magnetic material but maintaining the magnetic layer on the wall; depositing an insulating material (19a) to cover the magnetic layer.

该方法包括下列步骤：淀积足够厚度的一个非磁层(3)；非均质地蚀刻该非磁层以便在磁通引导的要求位置形成适宜尺寸的阶跃内壁；淀积一个磁性材料，以便在该内壁上形成一个磁层(9)，使得该磁层具有对应于该要求的磁迹宽度的一个厚度；去除不希望的淀积的磁性材料而保持在该内壁上的磁层；淀积一个绝缘材料(19a)以便覆盖该磁层。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。