查询词典 Ac

ABSTRACT:In 1970's,one method of AC induction motor control called Direct Torque Controlwas raised.

直接转矩控制是20世纪70年代提出的，在80年代中期发展起来的新型电机调速方法，是继矢量变换控制技术之后，且与之并行发展的一种新型的高性能的交流调速传动的控制技术。

In this paper, a stable and efficient control of the frequency of pure AC induction motor.

中文摘要本文介绍了一个稳定的和高效率的纯量变频控制交流感应马达。

The linear position sensors use emitter and receiver coil systems, precisely arranged on a printed circuit board, that are activated with a high frequency AC field and produce an inductive RLC circuit with the positioning element.

该线型位置传感器使用发射器和接收器线圈系统，精确地排列在一个印刷电路板上，它被一个高频交流电领域所激活，产生一个感应的RLC电路和定位元素。

Following formula calculates the inductive reactance of an ideal inductor (i.e., one with no losses) to a sinusoidal AC signal.

包括电感的电抗，下列的方程式用来计算一理想电感在一正弦波交流讯号下的电抗

For this reason, an optimal automatic timing control algorithm is proposed, that can restrain the switching frequency in a certain range to achieve the purpose of high efficiency and energy conservation. Taking such factors as inductive reactance at AC side, switching frequency, harmonic distortion rate and switching loss as well as the interaction among them into consideration, the formulas for inductive reactance and switching frequency are given; then by use of digital signal processor TMS320F2812, a prototype based on the proposed algorithm is implemented, and using this prototype the effectiveness and practicality of the proposed method are verified by experimental research and simulation.

文章提出了自动定时控制的优化算法，将开关频率限定在一定范围内，以达到高效节能的目的；综合考虑交流侧感抗、开关频率、谐波畸变率和开关损耗等指标，提出了主电路电感参数和开关频率的选择公式，并采用TMS320F2812数字信号处理器构造了试验样机，进行仿真和试验研究，其结果证明了该方法的有效性和实用性。

Their two other games in Italy in UEFA competition saw them awarded a 3-0 win against AC Fiorentina in the 1977/78 UEFA Cup second round after the ineligibility of a Fiorentina player. In the 1997/78 UEFA Cup quarter-finals, Inter gained a measure of revenge for their defeat the previous year by winning 1-0 at home and drawing 1-1 away.

他们和意大利球队的另外两场欧足联赛事的情况是这样的：1977/78赛季欧洲优胜者杯第二轮对佛罗伦萨，被判3-0获胜，因为佛罗伦萨使用了没有资格的球员。1977/78赛季的欧洲优胜者杯四分之一决赛，国际因前一年主场1-0的失败遭到了报复，客场是1-1。

Firstly, the transient stability of the modes by which some kinds of huge power suppliers are connected with AC power grid is analyzed and compared in detail; then a detailed transient stability simulation of a certain large-scale demonstration system is performed; finally some helpful conclusions are obtained: in the general situation, the bundling power transmission mode is favorable to increase the stability of sending system; if it is helpful to evidently increase the inertia of the equivalent leading group, the mode that connects the huge power supplier with sending system will be helpful to enhance the stability of sending system, however it is necessary to perform simulation and analysis while these principles are applied to FACT systems.

首先从机制上对几种大电源接入交流系统方式的暂态稳定性进行了详细的分析和比较；然后对大型算例系统进行了详尽的暂态稳定仿真；最终得出了一些有用的结论：一般情况下，打捆送电方式有利于提高送出系统的稳定性；如果有助于显著增加领前群的惯量，则与送端系统相联的方式也有助于提高送电系统的稳定性，但仍要结合具体系统进行分析。

The physicochemical properties of AC, such as high specific surface area, good electrical and thermal conductivities as well as the chemical inertness make it gain extensive attentions.

它具有比表面积大、导电和导热性佳、化学稳定性好、价格便宜等特点，受到了人们的广泛关注。

The author put forward the following opinions: civilian sport refers to non-official sports activities de-veloped among the masses; it is not provided with the characteristic of being passed on and continued generation by generation, can occur in a certain period, and disappear in a certain period; folk sport refers to sports activities closely related to civilian customs, mainly existing in civilian celebrative activities, religious activities and ritual ac-tivities; it is a form of sports culture passed on and continued generation by generation, provided with the character-istics of collectivity, inheritability and mode; national sport is divided into general type and special type; general na-tional sport refers to a special culture that once historically reflected and carried common psychological capacity and culture of a nation and is enjoyed by that nation; Chinese national sport, ancient Grecian sport and ancient Egyptian sport are specific forms of presentation of national sport; special national sport refers to a sports cultural form that is exclusively owned by a nation in modern time, reflects and carries common psychological capacity and culture of that nation, and is created and enjoyed by that nation; traditional sport refers to a stable sports culture that is historically inherited and gradually formed by a nation in practical activities in a long history, embodied in all as-pects of sports cultural activities and passed on generation by generation.

摘 要：民间体育是指非官方的在民众中开展的体育活动，它不具有世代相传和延续的特点，可以在某一时期出现，又可能在某一时期消失；民俗体育是指那些与民间风俗习惯关系密切，主要存在于民间节庆活动、宗教活动、祭祀活动中，是一种世代传承和延续的体育文化形态，具有集体性、传承性和模式性特点；民族体育有广义和狭义之分，广义民族体育指曾在历史上反映和承载着一个民族共同心理素质、共同文化，为该民族享用的一种特殊文化，中华民族体育、古希腊体育、古埃及体育都是民族体育的具体表现形式，狭义民族体育是指近现代一个民族所独有的，反映并承载该民族共同心理素质、共同文化并为该民族所创造和享用的一种体育文化形态；传统体育是指由历史沿袭下来，是民族在漫长的历史实践活动中积累而成的稳定的体育文化，体现在健身、养生、娱乐思维方式、行为方式等体育文化活动的各个方面，并通过社会心理结构及其它物化媒介(如棋盘、武术器械、文献典籍等)得以世代相传。

The method of slide-mode variable structure control is such a strategy that is characterized of low mathematical model precision, insensitiveness to system parameter variation and external disturbances, omission of parameter identifications, fast dynamic response and easy implementation. These advantages make it suitable to high performance vector controlled AC motor drives.

滑模变结构控制是一种强鲁棒性的控制方法，对系统数学模型精度要求不高，具有快速响应、对参数及外部扰动变化不敏感、无需系统在线辨识，实现简单而且很适合计算机实现等优点，因此，很适合高性能的交流电机矢量控制系统。

The system can be widely used in belt weighing and batching process control,etc.

介绍了基于智能模糊控制的嵌入式配料系统的设计方法，对模糊PID控制过程和系统调零作了重点的讨论，同时给出了PID控制的程序流程图和系统定长调零子程序。

"I dunno," she answered,"but if you show me aroun', I'll recognize it from the lighthouse just outside the porthole."

"我不知道，"她回答说，"如果你能带我转转，我能认出来的，因为灯塔就在舷窗外。"