一起保安段失电导致600MW机组跳闸引发的思考

国华宁海电厂2号机组(600MW)共配备6台磨煤机,从下层到上层依次编号为A,B,C,D,E,F。其中,A,B,C磨煤机电源取自6kVA段,D,E,F磨煤机电源取自6kVB段,A,B,C磨煤     

甜蜜蜜

懒洋洋的午后,好友相聚,品尝着自己亲手制作的甜品,聊聊过去,说说现在,谈谈未来;抑或在茶余饭后,一家人其乐融融地坐在沙发上,一边谈天说地,一边品尝甜品,这是多么美妙惬意的事儿。其实,很多人喜欢甜品,不仅仅是因为它甜蜜的滋味,更是因为它能给人们带来无限的温暖和幸福。     

欢迎订阅《电工技术》杂志

实用技术类月刊国内外公开发行国家级期刊《电工技术》由重庆西南信息有限公司主管、主办,1980年创刊,国内外公开发行,每月10臼出版,是国内外同类杂志中具有很大影响力的实用性技术杂志。面向行业:电力,新能源,冶金,石化,环保,矿业,水泥,造纸,轨道交通,机械制造等     

中国火电建设发展史(6)

"中国火电建设发展史"原系"中华人民共和国电力工业史"的一部分,该书由10多位资深专家分工撰编多年,但迄今未能付梓出版。现将其中"火电建设"部分单独刊出,本刊以连载方式发表,以飨读者。写史要求实事求是,秉笔直抒,总结经验教训,探讨发展规律,以史为鉴,鉴往知来。火力发电在我国电力工业史中始终处于主导地位,在21世纪的电力发展中,火电建设仍将处于主导地位,愿全国火电建设者,不懈努力,为全面建成小康社会和实现四个现代化做出自己的贡献。     

逝水流年 摄影凝固的时光储存回忆——讲述五位大学生结缘摄影的故事

有些人,有些事,有些记忆,我们错过了,我们遗憾了,留下的或许就只有感叹。然而,在当今昌明的科技之下,摄影,也许就是我们弥补遗憾或者说回忆过去的最好方式了!当神经紧绷,心灵空虚之时,翻出你过往记忆,细细体会那些年,那些人和那些事。当我们想明白这一切不过就是过眼云烟的时候,于是,就给自己一剂强心剂,勇往直前。     

假名牌市场的存在机理及其对策分析

假名牌市场的普遍存在,严重扰乱了我国社会主义市场经济秩序,影响了企业间的公平竞争,同时也反映出目前我国消费市场上,市场运行机制不完善,政府执法监督不严等诸多问题.结合对假名牌市场相关信息的调查数据,本文通过对假名牌市场的现状,以及给我国市场经济所带来的危害分析,从消费者,制造商、政府三方面探讨了假名牌市场存在的原因,再针对我国目前在打击假名牌方面存在的问题,参考国外的打假经验,提出了几点打假建议.     

正视“亚健康”保健器具市场大有可为

什么是亚健康? 环境污染,饮食不当,作息无规律,家庭负担,看病贵,看病难,感情危机,人际关系错综复杂等诸多不利因素不断地困扰和影响着我们,久而久之,我们的心理就会出现异常,行为就会出现偏颇,身体不适、情绪不佳、心情烦躁等不适症状随之而来,即出现亚健康.     

万元家庭影院配置

Q江苏省常州市吴凡问：我从夫人的单位里看到贵刊,感觉非常好!长了不少见识,现有一事相求,最近我的新居将要装修了,我想将客厅音响系统好好规划一下（我的客厅区域深3970mm,宽4190mm,旁边就是餐厅,没有隔断,餐厅区域总面积有24m^2,层高2650mm）,我的孩子在学习萨克斯,需要用到伴奏,因此音响是很需要的,我想既然如此,     

乌镇印象

追忆旧时光,浙江乌镇无疑是个顶好的地方。黄昏,一个人默默走进乌镇,似乎可以感受到时光的流转。我想,乌镇是本不想以古明世的,它默默地沉积着自己,不经意间流露出的古色古韵,给了世人一个措手不及,几乎一夜之间,乌镇名扬天下。走进乌镇,仿佛走进了一个千年的梦境,古老的木质结构的村落里,深藏了江南的历史和浓郁的文化。那种沧桑与沉静,时光与流水,悠然与斑驳,组成一幅天然的图画,令我们不得不去怀念去追忆、去感慨。     

2011,曲靖供电局这样走过

日月开新元,天地又一春。捧着收获的果实,满怀喜悦的心情,我们将握别2011年;带着希望,带着憧憬,带着执着与追求,去拥抱2012年。在过去的一年里,曲靖供电局全面贯彻中长期发展战略,着力强化创先工作,狠抓安全生产,做好电力保障,深化优质服务,推进电网发展,强化内部管理,提升队伍素质,促进企业和谐,各项工作都迈上了崭新的台阶。     

THEORY OF A SYNCHRONOUS MACHINE WITH A SELF-LEVITATED ROTOR

ABSTRACT

The properties of an ironless rotor synchronous machine (SM) with null-flux windings on the stator and radial displacement of the rotor are considered. The system of the SM equations are derived. These equations are based on an analytic representation of a three-dimensional excitation field and on considering the SM as a dynamic system with three generalized coordinates, two of which are the coordinates of the Center of rotor mass and one is the angle coordinate which characterizes the rotation of the rotor on its own axis.

On the basis of the solution of the equations we obtain the relations for all the basic quantities: radial and centering forces, radial suspension stiffness and parameters of the null-flux circuit. They characterize all the properties of the SM in the state when the rotating rotor undergoes a radial displacement.     

A STRATEGY TO ISOLATE A SWITCHING DEVICE FAULT IN A CURRENT REGULATED MOTOR DRIVE

ABSTRACT

In this paper a new, improved induction motor control topology is proposed which allows for continuous, disturbance-free operation of the drive with a failed short-circuited switch in one leg of the inverter. The analysis of this control strategy and the computer simulation are explored. The experimental results from hardware are attached to verify the simulation results. A complete control strategy combined with short-circuit fault and open-circuit fault is also included.     

关于量化和A/D-D/A的讨论

数字、量化、量化效应、模拟、模拟量、A/D转换、D/A转换是计算机控制工程和控制理论上的常见概念.静心推敲,发现有不少流行性的误解.例如：不是“量化”而是截尾或四舍五入,不是“数字量”而是bit量,不是“模拟量”而是物理量等.     

单片机在转速测速器中的应用

介绍一种由单片机８９Ｃ５１构成的高精度多功能转速测试器的工作原理,设计思想,软硬件配置及应用方法。该测速器是通过采集光电编码器发出的脉冲信号由单片机记数,数据经内部程序计算、分析、处理后,按实际要求做出相应的继电器输出,模拟量输出和串行口输出。它的实时转速值通过ＬＥＤ显示非常方便直观,还可以通过按键显示瞬时转速值,事先设定的转速值。它具有超速报警与串行通讯口功能,还可以配接不同线数的光电编码器（指     

A VISION OF FRAM AS A FUSION MEMORY

ABSTRACT

The purpose of this paper is to attempt to find a plausible solution for a high density FRAM (Ferroelectric Random Access Memory). To complete this, firstly, we give a very brief but an important review of how FRAM technologies have been evolved during the past many years. Secondly, not only are a few examples demonstrated in terms of how a FRAM-embedded system is advantageous when adopted in a system but it is also put forward how FRAM can play an essential role in a fusion memory. Finally, several process technologies for integrating a reliable high-density FRAM are mentioned, accordingly resulting in very reliable cell-charge populations after full integration, along with wafer-level reliabilities.     

A Coupled-Reactor-Commutating Sinusoidal-Wave Inverter

A coupled-reactor-commutating sinusoidal-wave current-source inverter is described. The inverter consists of two coupled-reactor-commutating inverters. By superposing the output currents of these two inverters, output currents of a 180° conducting angle are formed, and are controlled in order to achieve a sinusoidal waveform. The operation and the control scheme of the inverter are described, and experimental results are presented. Compared with the usual PWM voltage-source inverters, the on-off frequency of each chopper may be decreased almost to one tenth of that of the PWM inverter.     

关于调度会议电视及其传输信道的研究

介绍了国内外会议电视发展的情况，着重阐述会议电视的功能和调度会议电视的特点，会议电视系统的组成，并对几种传输方式进行探讨和比较，提出利用数字微波备用信道作为调度会议电视系统的通道，以获得较大的经济效益。     

A THYRISTORIZED A.C. VOLTAGE CONTROLLER WITH SINUSOIDAL OUTPUT

ABSTRACT

In this paper a thyristor voltage controller suitable for high power loads is presented. A load voltage higher than that of the supply can be obtained without difficulty. Thyrsitor switches are used in a secondary circuit such that voltage control is achieved via flux level variation of an output coil. The load voltage is varied in steps which can be made as narrow as desired but distortion and switching transients in the load circuit are avoided. Theoretical and experimental results of a prototype are presented and compared. If the load is an inductor, the proposed arrangement can be used as a variable reactive power compensator without harmonic current injection into the mains supply.     

ANALYTICAL APPROACH TO THE OPERATION OF A SYNCHRONOUS MACHINE ASSOCIATED WITH A THYRISTOR BRIDGE

ABSTRACT

A synchronous machine associated with a thyristor bridge operates normally under unbalanced conditions which are described and studied in the present paper. Natural cut-off thyristors is used in the present system where the gates of thyristors are controlled by the rotor position. It is assumed that the machine has salient poles and damper windings. Both motor and generator operations are contemplated.

An analytical approach has been used, and the exact shape of the currents has been considered. The commutation problem is studied in detail, taking into consideration the transient effects of the armature circuits and the limited value of the smoothing reactor. The different expressions are given in terms of the classical machine constants which can be directly measured or furnished by the manufacturer. Comparison between theoretical and practical results are given.     

循环流化床锅炉联合运行的技术经济性分析

本文针对循环流化床燃烧锅炉主要特点,分析了这种锅炉与链条火床炉配套联合运行的模式的热电联产的技术经济性,提出综合利用我国煤炭资源、保护环境,开发循环流化床燃烧锅炉应用的几点建议。