交流分析

The main contents of this subject is the basic theory of the windings, including the calculation of the electric potential and magnetomotive force and polarity of the winding\current and voltage.

本课题内容有绕组的基本理论，概述了交流绕组的电动势、磁动势等的计算以及绕组线圈、电流、电压的极性，这些为讲述绕组分析方法时提供了基础。

So, it is very difficult to monitor and protect the rotating rectifier. This paper theoretically analyses the armature current and magnetomotive force in AC exciter of brushless synchronous machine with rotating rectifier. Under the normal or fault conditions of rotating rectifier, the mathematical expressions of the armature current, the m.m.f and induced electromotive force are approached.

本文通过对旋转整流器在正常与故障状态下的交流励磁机电枢电流和电枢电势作了初步的理论分析，推导出旋转整流器在正常与故障状态下电枢电流、空间谐波合成磁势及其感应电势的数学表达式。

By means of analyzing the difference between HVDC transmission line and traditional HVAC transmission lines, it is proved that it is not suitable to apply superposition principle to the power grid containing HVDC transmission lines, thus following conclusions are obtained: in the place near to HVDC transmission line the fundamental frequency fault component element should be not adopted; and there is definite relation between the maloperation of directional comparison pilot protection applied in practical project and the adoption of fundamental frequency fault component element.

通过分析HVDC的特性与传统交流系统的不同，证明叠加原理不能应用在含有HVDC的系统中，从而得出结论：在HVDC附近不应该采用工频故障分量元件，实际工程中的纵联方向保护误动作与使用工频故障分量元件有一定关系。

The weight loss method, electrochemical impedance spectroscopy and surface analysis methods were employed to investigate the corrosion behavior of steel A3 under the combined effect of Streptomyces and Nocardia sp.

采用腐蚀失重法、电化学交流阻抗法和表面分析技术研究了A3钢在链霉菌和诺卡氏菌共同作用下的腐蚀行为。

We compared three competing hypotheses which maintained that euprimates originated in Africa, the India subcontinent, or East Asia. Combined the recent achievements on the mammalian fauna exchanges during early Eocene between Europe and Africa, Europe and Asia, and Asia and India subcontinent, the paleogeographic models of around Turgai Strait, the new dating results of the collision between Indian subcontinent and Asia, and the phylogenetic analysis of euprimate, we suggested that the Asian-origin hypothesis of euprimates are more reliable.

全面对比了真灵长类动物亚洲起源说、非洲起源说和印度次大陆起源说，结合前人有关欧洲与非洲之间、欧洲与亚洲之间、亚洲与印度次大陆之间早始新世时的动物群交流的研究，以及有关图尔盖海峡古地理、印度板块与欧亚板块碰撞时间的研究成果，在真灵长类动物分支系统分析的基础上，提出真灵长类动物亚洲起源说是目前获得支持证据最多的假说。

Harmonic problems in the power system of electric power pulsive shipping are discussed in this articl.

本文对电力推进船舶电网的谐波问题进行了深入的研究。首先对船舶电气进行了分类和归纳，研究了谐波对船舶电气产生的影响和危害；对于不同的电路拓扑结构，尤其以用电设备交流侧电路结构的不同，深入分析了各自谐波产生的原因、谐波的特点。

For electric power pulsive shipping, the voltage is not always normal, especially when the main motor is starting, and three-phase bridge commutated circuit is used widely, so, a new method to compute harmonic is developed, which is more accurate and practical, is more adapt to the ship condictions.

因此，本文在上述文献的基础上，对接入电压波形畸变的电网中的三相桥式整流电路进行了分析，采用了一种实用的新方法来计算三相桥式整流器所产生的谐波电流。本方法考虑了交流侧电抗及电网中存在的谐波电压，导出了交直流两侧谐波电流的计算公式。

Polimeni theorizes that humor and spirituality emerged together, perhaps as ways for humans to relieve stress, communicate and make social connections in lieu of grooming, roughhousing and other, more direct means used by our primate ancestors.

据波里曼尼分析，幽默和精神意识是同时出现的，或许正如人类舒缓精神压力，交流并形成社会联系，取代了梳洗、粗暴对待彼此等其他我们灵长类祖先采用的更直接的方式。

According to the definition and the distribution of VSR's voltage space vector, the introduction of a rule-based SVPWM current control strategy, with non-fixed switching frequency and dual hysteresis loops, that obviously improves the performance of current control. Based on two kinds of control strategies of VSR under unbalanced grid condition, the introduction of a new VSR control strategy featuring undamped-oscillation that simplifies the controller structure and effectively improves VSR's performance under unbalanced grid condition. A systematic description of the state switching in trilogic PWM signal generation of threephase CSR by using the conversion between bilogic and trilogic switching functions.

作者在如下工作的基础上对PWM整流器的一些关键问题提出了自己的研究思路、观点和方法：根据PWM整流器网侧矢量关系，直观地描述了其四象限运行的基本原理及特征；定量分析了VSR、CSR的PWM换相过程及波形特征；引入等效变压器模型并详细分析了VSR、CSR基于d—q模型的动、静态特性；提出了满足四象限有功、无功运行指标时的VSR交流侧电感设计方法；并提出了依据控制系统跟随性和抗扰性性能指标设计VSR、CSR直流侧储能元件的参数计算方法；在研究了VSR电流控制策略基础上，提出了影响VSR电流控制的几个要素，并进行了定量分析；根据VSR空间电压矢量的定义及分布，提出了基于规则控制的不定频滞环空间矢量PWM电流控制策略，并由此提出了具有双滞环特性的不定频滞环优化SVPWM电流控制策略，有效地改进了滞环PWM电流控制性能。

Permanent magnet synchronous motor driven by triphase sinusoidal current is research object in this paper. On the basis of analysis of the structure, movement principle and math model of PMSM, Fundamental theories and structure of the system of PMSM alternating current servo systems based on DTC are discussed. Then Simulation models of traditional PMSM DTC and PMSM DTC based on vectors subdivision are established separately.

本文以三相正弦波驱动的永磁同步电机为研究对象，在分析永磁同步电机结构及数学模型的基础上，系统阐述了基于直接转矩控制的永磁同步电机交流伺服系统的基本原理和系统构成，并在MATLAB仿真环境下分别建立了传统直接转矩控制和基于矢量细分算法的直接转矩控制系统的仿真模型。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。