查询词典 magnetic torque

A new brushless DC motor DTC scheme was studied to solve those problems associated with direct torque controlof brushless DC motor,such as difficulty to control flux and complexity to estimate torque.The flux hysteresis controller was ignored in the constant torque region and an improved method was proposed to make the estimation of torque easier.The proper stator voltage space vector was selected based on the output of the torque hysteresis controller and the sector which the current rotor flux locates in.

摘 要：针对无刷直流电机直接转矩控制中磁链观测困难、控制复杂等问题，提出了一种应用于无刷直流电机二二导通方式下的新型直接转矩控制方法：在电机基频以下调速时，略去了常规的磁链观测控制环节，改进了转矩计算方法，通过转矩滞环控制选择所施加的空间电压矢量。

By analyzing the engine driving torque characteristics and the transmission inertia torque while speed ratio is changed under transient condition, a new synthetic control algorithm is developed which can approach engine target torque by compensating engine output torque with transmission system inertia torque.

本文从金属带式无级变速传动的传动机理入手，通过建立发动机和无级变速器的速比变化率模型，研究了发动机与无级变速器的匹配控制策略。

An apparatus made by our lab is used for direct measurement of torque of yarns. The torque-twist relation curves, torque-relaxation behavior of several kinds of yarns at room temperature and heat-setting temperature are given. After analyzing the difference of different yarn torque it can be found that the special structures of composite yarns made of polyester filament and wool staple fibers mainly cause the high residual torque.

应用自行研制的直接测量纱线扭矩装置，这里测试数种纱线的扭矩-捻度关系曲线及其在常温和热状态下的扭应力松弛关系曲线，分析相同捻度下各种纱线扭矩差异的根源，发现涤长丝与毛短纤复合纱线的特殊结构是造成复合纱线残余扭矩较大的主要原因。

The power of motor is positive proportion to square root of equality of square pure torque .the pure torque is combined by suspension point torque and balancing weight torque ,so the change of suspension point's motion law and balancing weight offset angle can causes pure torque variation .especially, the suspension motion law is decided by configuration curve of hinder heaven sheave .so the paper has emphatically studied and analysis the law that the configuration curve of hinder heaven sheave brings the change of pumping unit energy-saving .

电机功率与减速器曲柄轴净扭矩均方根成正比，减速器曲柄轴净扭矩是由悬点载荷产生的扭矩和平衡重产生的平衡力矩合成的；改变悬点运动规律和平衡重的滞后角可以引起净扭矩的变化，其中悬点运动规律是由后天轮曲线决定的，因此，本文依据此原理着重研究分析了后天轮曲线影响抽油及节能的变化规律。

This thesis proposed the design and implementation of an ASIC for the motor control with DTC technology. Note that this ASIC is implemented by cell-based Design style with Verilog language.The basic principle of the Direct Torque Control is to select the switch sequence of the inverter. Those switches will control the magnetism and torque of the stator, to induce a fast response of the induction motor. Furthermore, the d-q axle's static coordinate, which is transferred from both the three-phase current and voltage, is used to compute the stator's magnetism and torque. By comparing with original values, those magnetism and torque will be calculated and set to new data. Then the switching table and the hysteresis controller are decided with the new data to generate a voltage vector and to control the stator magnetism and torque.

直接转矩控制的基本原理为经由侦测马达定子磁通与转子转速，来适当的选择变频器功率电晶体的切换状态，以获得快速且不易受外在环境影响的马达控制响应；首先，根据量测三相电流与利用变频器的切换状态取得马达的三相电压，将其转换至d-q轴静止座标，然后藉此估测马达的磁通量与转矩量，再分别与侦测的定子磁通量和转矩量比较后，得到定子磁通量与转矩量比较的结果，再利用DTC电压向量切换表(DTC Voltage Vector Switching table)，依定子磁通与转矩的比较值及马达所在的角度位置，来选择一个适当的电压向量，进而依切换顺序来激发功率电晶体，达到控制感应马达的目的。

Electromagnetics course mainly including basic phenomena and laws of electro- magnetics, electrostatic field in vacuum, in conductor and in electric medium, electric energy, stabilized current, stabilized magnetic field and its basic laws, electric and magnetic fields caused by a moving chager in lower speed, the transform of electric and magnetic fields between different systems of coordinates, inductive laws, eddy field, self inductance, mutual inductance and transient, molecule current and magnetic substance, ferromagnet, boundary conditions, magnetic circuit theorem, energy of magnetic field and density of magnetic energy, displacement current, Maxwell's equation, electromagnetic wave, Poynting vector.

电磁学课程的主要内容包括：静电的基本现象和基本定律，真空中的静电场，导体和电介质中的静电场，电场的能量与电场能量密度，稳恒电流，稳恒电流磁场的基本定律，运动电荷的电磁场，不同参照系之间电磁场的变换，电磁感应定律，涡旋电场，互感，自感，暂态过程，分子电流与磁介质，铁磁体，边界条件，磁路定理，磁场的能量和磁能密度，位移电流， Maxwell 方程组，电磁波和玻印廷矢量等。

Some people introduce subphotosphere magnetic charges or dipole, which can fit magnetic field on the photosphere, then the separatrix and separator above and on the photosphere can be located, the comparison between their location and location of flare ribbon support the idea of magnetic reconnection. It is called Source Method. Some people extrapolate magnetic fields of photosphere to corona by some method, then use QSLs method to investigate the relations between flare ribbons and magnetic field topology. Some people study relations between flare ribbons and singular point on the plane above photosphere. Some people investigate magnetic topology by analyzing magnetic field of photosphere directly.

或者以观测的光球磁场为基础，来构造光球下的磁荷或磁偶极等光球下磁源，进而研究光球上的磁拓扑结构与耀斑的关系；或者利用各种外推方法将光球磁场进行外推，然后用准分隔层的方法来研究磁拓扑结构与耀斑的关系；或者利用势场模型外推光球磁场，然后研究光球之上平行于光球的某一平面的两维奇点与耀斑的关系；或者直接利用观测的光球矢量场来研究磁场拓扑。

In the dehydrogenation process of HD process, the temperature set at 580℃ and pressure set at 100Pa is a perfect parameter, it can make the magnet to have high magnetic performance. In the HDDR process experiment, the paper contrast four HDDR process such as C-HDDR V-HDDR V-HD-S-DR and d-HDDR by the anisotropy and magnetic performance of ternary NdFeB magnetic material. The results show that adjusting the parameter of the d-HDDR process can make the anisotropy and magnetic performance of ternary NdFeB magnetic powders to catch up with the hexahydric NdFeBCoZrGa magnetic powders. At the end the paper discusses the betterment of the equipment which produces ternary NdFeB magnetic with the d-HDDR process.

和580℃的脱氢温度相搭配的脱氢气压选择在100Pa左右是理想的工艺参数，这样的搭配使得最终烧结磁体综合磁性能优异；在HDDR制粉工艺实验中，本文对比了C-HDDR、V-HDDR、V-HD-S-DR和d-HDDR四种HDDR工艺对于三元NdFeB合金各向异性和磁性能的影响，得出结论：通过发展d-HDDR工艺，调整工艺参数和控制水平，可以使三元NdFeB合金磁粉的性能达到或接近六元NdFeBCoZrGa合金磁粉的水平，在文章末尾，还对配合使用d-HDDR工艺设备的改造进行了分析。

Seeing that the basic researches of the method of metal magnetic memory insufficiently, this text has done the following work mainly:(1)Studied the basic theory of the method of metal magnetic memory;(2)Studied the signal of metal magnetic memory of samples both anneals and not anneals in natural magnetic field and drive magnetic field under the drawn loads;(3) Studied the signal of metal magnetic memory of anneals samples in three magnetic fields under the drawn loads.

鉴于其基础研究工作不足，本文主要做了如下工作：(1)系统地研究了金属磁记忆检测技术的基本理论：(2)研究了退火试件和未退火试件在自然磁场和激励磁场环境中进行拉伸的磁记忆信号；(3)研究了退火试件在三种磁场环境中进行拉伸试验的磁记忆信号。

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。

Article 144 The Government of the Hong Kong Special Administrative Region shall maintain the policy previously practised in Hong Kong in respect of subventions for non-governmental organizations in fields such as education, medicine and health, culture, art, recreation, sports, social welfare and social

第一百四十四条香港特别行政区政府保持原在香港实行的对教育、医疗卫生、文化、艺术、康乐、体育、社会福利、社会工作等方面的民间团体机构的资助政策。原在香港各资助机构任职的人员均可根据原有制度继续受聘。

Small wonder, then, that the Chinese spend more in the shop than any other group of foreign visitors do .

这样的小惊喜，使中国顾客比任何国家的人消费得更多。