磁矩

This technique is used for the axisymmetric magneticstatic problems and the result is good. In the second example of the forth chapter, the error of the third–order Asymptotic Boundary Condition is lower than that of the second-order Asympototic Boundary Condition.

第五章针对这一问题，进一步对渐近边界条件进行了推导，分析了一些特殊电荷和电流分布情况下，电位、标量磁位和矢量磁位的多极矩展开式中各极矩项的性质。

In order to implement the algorithm, a linearization method is applied in an extremely short sampling cycle to calculate the increments of torque and flux magnitude, to derive the linear equation between the desired stator flux linkage vector increment angle and the increments of torque and flux magnitude, to derive the stator voltage vector reference and to determine the next position of the stator flux linkage vector.

算法的实现运用了线性化的方法，在一个极小的采样周期内，计算出转矩增量和磁通增量，以此推导出所需的定子磁链增量角与转矩增量及磁通增量两者之间的线性方程，进一步导出所需的定子电压矢量，并确定新的定子磁链位置。

From the concept of winding inductance、 magnetic linkage and the store coenergy, this paper deduces the quantitative relationship between motor speed, n, reluctance torque and winding's voltage, Us, and investigates whether it is correct or not through tests.

分析了开关磁阻电动机的一种调速方法——调压调速；从绕组电感、磁链及磁共能的概念出发，导出调压调速方式下电机转速n，磁阻转矩M及绕组端电压US之间的定量关系，并通过实验验证了三者之间关系的正确性；给出适合于开关磁阻电动机调压调速系统的8098单片机使用PID数字控制器的控制算法，最后介绍2。

Based on the mutual inductance,a technical scheme to change the parameters of asymmetrical phase windings was proposed.

通过引入互感的方法可以定量计算磁链的减小量，并给出了互感计算式，利用有限元法分析了一台样机互感随转子位置和电流的变化规律，理论推导了互感对平均转矩影响的程度，研究了四相8/6极开关磁阻电动机稳态转矩波形在两种绕组连接方式下的不规则特性，结合互感特性，提出了改变不对称相绕组参数的技术方案。

ABSTRACT The researches of this thesis are carried out around the development of high performance machine tool spindle permanent magnet synchronous motor and its drive system. Five parts are included: First of all, concerning the operating characteristics of the machine tool spindle drive system, the optimum current control strategies of spindle PMSM are determined; The design rules of spindle PMSM's key parameters are summarized, based on the study on the influences of the design parameters on the performances of the PMSM operating at different current control strategies; The practical methods to improve the flux-weakening ability of the PMSM are presented; Based on the analysis and comparison of the operating performances of PMSM with different rotor structures, a novel PMSM rotor structure, which is of excellent mechanical performance, suitable for fluxweakening operation and can improve the torque output capacity in the same time, is presented.

本文围绕高性能机床主轴永磁同步电动机及其传动系统的设计研究展开，所做工作主要包括五部分：首先，确定了主轴永磁同步电动机定子电流的最优控制策略；通过对不同控制策略下主要设计参数对主轴永磁同步电动机性能影响的计算研究，总结了参数设计规律；提出了永磁同步电动机弱磁扩速的实用措施；在分析比较不同转子磁路结构电机的性能，尤其是弱磁扩速能力的基础上，提出了一种机械性能优越，易于弱磁扩速，同时能保证电机恒转矩运行时的转矩输出能力的新型转子磁路结构。

Direct torque control is another high performance control technique of AC motor, it discard the decouple idea of vector control, but adapt flux oriented control and transient space vector theory, directly control stator flux and torque, it has the advantage of rapid torque response and less relying on stator parameters, but has the disadvantage of bigger torque ripple.

直接转矩控制技术是继矢量控制技术之后的又一种交流电机高性能控制技术，它摈弃了矢量控制中解耦的控制思想，采用定子磁链定向和瞬时空间矢量理论，直接对电机定子磁链和转矩进行控制，具有转矩响应快、对电机参数依赖小的优点，但它的不足之处就是存在转矩脉动。

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。

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。

Due to hexagon flux control or six-section circle-flux used in traditional direct torque control,it is easy to form large torque ripple twelve section control method of voltage select table and the implementation was presented.

由于传统的直接转矩控制采用六边形磁链控制或六区间的圆形磁链控制，容易造成转矩脉动大。

This invention concerns a current control process for a feed-in voltage converter, wherein a detected flux-inducing current component and a detected torque-inducing currrent component of an actual currrent vector of a rotating field machine are each controlled for a flux-inducing current component set value and a torque-inducing current component set value of the rotating field machine. To that effect, a control set-value (DELTA u*sp, DELTA u*sq) is determined, dependent each time upon a determined current component control deviation. From these, current components of an actual current vector are formed each time by overlay of a formed pilot value (u*spvor, u*sqvor). This invention also concerns a device for carrying out this process.

本发明涉及一种用于馈入电压式变流器的电流调节方法，其中分别将所检测的一感应式电机的一实际电流向量（i s 的磁通感应电流分量和一转矩感应电流分量i sq ）调节至该感应式电机的一额定电流向量的一磁通感应分量额定值和一转矩感应电流分量额定值，在这种情况下，分别根据所检测的一电流分量调节偏差计算出一调节器调节量（△u * sp ，△u * sq ），由这两个调节器调节量分别通过叠加所形成的一预控制量（u * spvor ，u * sqvor ）形成一额定电压向量的电压分量（u * sp ，u * sq ），本发明还涉及一种用于实施该方法的装置。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。