It has been over a decade since the Chinese publication of Line Loss in Electric Power Systems. To keep pace with technological developments, I started a revision as early as 2002, following the main principles that the theoretical framework and characteristics of the first edition should be retained, with new contents added according to new problems after the reform of electric power systems and the new requirements for line loss management practices and in combination with practical experience.
上傳時(shí)間： 2020-06-07
上傳用戶：shancjb
It all started rather innocuously. I walked into Dr GT Murthy’s office one fine day, andchanged my life. “Doc” was then the General Manager, Central R&D, of a very largeelectrical company headquartered in Bombay. In his new state-of-the-art electronics center,he had hand-picked some of India’s best engineers (over a hundred already) ever assembledunder one roof. Luckily, he too was originally a Physicist, and that certainly helped me gainsome empathy. Nowadays he is in retirement, but I will always remember him as athoroughly fair, honest and facts-oriented person, who led by example. There were severalthings I absorbed from him that are very much part of my basic engineering persona today.You can certainly look upon this book as an extension of what Doc started many years agoin India … because that’s what it really is! I certainly wouldn’t be here today if I hadn’t metDoc. And in fact, several of the brash, high-flying managers I’ve met in recent years,desperately need some sort of crash course in technology and human values from Doc!
標(biāo)簽： 開關(guān)電源
上傳時(shí)間： 2021-11-23
上傳用戶：
該數(shù)字溫度傳感器具有13位(0.03125°C)分辨率，并且?guī)в锌捎捎脩艟幊淘O(shè)置的非易失性溫度上、下限溫度報(bào)警值；通信速率可變的Single-Line 協(xié)議，最高速率可達(dá)25kb/s，支持多節(jié)點(diǎn)主從通信模式。
標(biāo)簽： 溫度傳感器
上傳時(shí)間： 2022-07-01
上傳用戶：aben
Example091.判斷控件類型.zip Example092.Line控件.zip Example093.使用Shape控件.zip Example094.引入系統(tǒng)監(jiān)視器.zip Example095.媒體文件瀏覽器.zip Example096.列表播放媒體文件.zip Example097.在應(yīng)用程序之間進(jìn)行拖放操作.zip Example098.文本文件的拖放操作.zip Example099.圖像和圖像文件的拖放.zip Example100.使用WebBrowser控件瀏覽網(wǎng)頁.zip
標(biāo)簽： Visual Basic 090 100
上傳時(shí)間： 2013-05-22
上傳用戶：一諾88
隨著電力電子技術(shù)、微處理器技術(shù)以及新的電機(jī)控制技術(shù)的發(fā)展，交流調(diào)速性能日益提高。變頻調(diào)速技術(shù)的出現(xiàn)使交流調(diào)速系統(tǒng)有取代直流調(diào)速系統(tǒng)的趨勢(shì)。但是國民經(jīng)濟(jì)的快速發(fā)展要求交流變頻調(diào)速系統(tǒng)具有更高的調(diào)速精度、更大的調(diào)速范圍和更快的響應(yīng)速度，一般的通用變頻器已經(jīng)不能滿足工業(yè)應(yīng)用的需求，而交流電機(jī)矢量控制調(diào)速系統(tǒng)能夠很好的滿足這個(gè)要求。矢量控制(Field Oriented Control)，能夠?qū)崿F(xiàn)交流電機(jī)電磁轉(zhuǎn)矩的快速控制，本文對(duì)三相交流異步電機(jī)的矢量控制系統(tǒng)進(jìn)行了研究和分析，以高性能數(shù)字信號(hào)處理器為硬件平臺(tái)設(shè)計(jì)了基于DSP的三相交流異步電機(jī)的矢量控制系統(tǒng)，并分析了逆變器死區(qū)效應(yīng)的產(chǎn)生，實(shí)現(xiàn)了逆變器死區(qū)的補(bǔ)償。 本文介紹了交流調(diào)速及其相關(guān)技術(shù)的發(fā)展，變頻調(diào)速的方案以及國內(nèi)外對(duì)矢量控制的研究狀況。以三相交流異步電機(jī)在三相靜止坐標(biāo)系下的數(shù)學(xué)模型為基礎(chǔ)，通過Clarke變換和Parke變換得到三相交流異步電機(jī)在兩相旋轉(zhuǎn)坐標(biāo)系下的數(shù)學(xué)模型，并利用轉(zhuǎn)子磁場(chǎng)定向的方法，對(duì)該模型進(jìn)行分析，設(shè)計(jì)了轉(zhuǎn)子磁鏈觀測(cè)器，以實(shí)現(xiàn)交流電機(jī)電流量的有效解耦，得到定子電流的轉(zhuǎn)矩分量和勵(lì)磁分量。仿照直流電機(jī)的控制方法，設(shè)計(jì)了矢量控制算法的電流與速度雙閉環(huán)控制系統(tǒng)。設(shè)計(jì)了以TMS320LF2407A為主控制器的硬件平臺(tái)，在此基礎(chǔ)上實(shí)現(xiàn)了矢量控制算法，論述了電壓空間矢量調(diào)制(SVPWM)的原理和方法，并對(duì)其進(jìn)行了改進(jìn)。最后對(duì)逆變器的死區(qū)進(jìn)行了補(bǔ)償。 實(shí)驗(yàn)表明基于轉(zhuǎn)子磁場(chǎng)定向的矢量控制(FOC)系統(tǒng)，結(jié)構(gòu)簡(jiǎn)單，電流解耦方便，動(dòng)態(tài)性能好，精度較高，能夠基本滿足現(xiàn)代交流電機(jī)控制系統(tǒng)的轉(zhuǎn)矩和速度要求。
上傳時(shí)間： 2013-05-24
上傳用戶：李彥東
In higher power applications to utilize the full line power and reduce line currentharmonics
標(biāo)簽： Pre-Regulator Interleaved Design Review
上傳時(shí)間： 2013-06-04
上傳用戶：lepoke
該論文討論如何采用一種串行無逆的Berlekamp-Massey(BM)算法,設(shè)計(jì)應(yīng)用于DVB系統(tǒng)中的RS(204,188)信道編碼/解碼電路,并通過FPGA的驗(yàn)證.RS解碼器的設(shè)計(jì)采用無逆BM算法,并利用串行方式來實(shí)現(xiàn),不僅避免了求逆運(yùn)算,而且只需用3個(gè)有限域乘法器就可以實(shí)現(xiàn),大大的降低了硬件實(shí)現(xiàn)的復(fù)雜度,并且因?yàn)樵谟布?shí)現(xiàn)上,采用了3級(jí)流水線(pipe-line)的處理結(jié)構(gòu).RS編碼器的設(shè)計(jì)中,利用有限域常數(shù)乘法器的特性對(duì)編碼電路進(jìn)行優(yōu)化.這些技術(shù)的采用大大的提高了RS編/解碼器的效率,節(jié)省了RS編/解碼器所占用資源.
上傳時(shí)間： 2013-08-05
上傳用戶：BOBOniu
隨著信息寬帶化和高速化的發(fā)展，以前的低速PCB已完全不能滿足日益增長(zhǎng)信息化發(fā)展的需要，而高速PCB的出現(xiàn)將對(duì)硬件人員提出更高的要求，僅僅依靠自
標(biāo)簽： Cadence ALlegro PCB 信號(hào)完整性
上傳時(shí)間： 2013-05-22
上傳用戶：julin2009
General Description The LM621 is a bipolar IC designed for commutation of brushless DC motors. The part is compatible with both three- and four-phase motors. It can directly drive the power switching devices used to drive the motor. The LM621 provides an adjustable dead-time circuit to eliminate ``shootthrough'' current spiking in the power switching circuitry. Operation is from a 5V supply, but output swings of up to 40V are accommodated. The part is packaged in an 18-pin, dual-in-line package.
上傳時(shí)間： 2013-07-24
上傳用戶：sdq_123
FEATURES Unique 1-Wire interface requires only one port pin for communication Multidrop capability simplifies distributed temperature sensing applications Requires no external components Can be powered from data line. Power supply range is 3.0V to 5.5V Zero standby power required Measures temperatures from -55°C to +125°C. Fahrenheit equivalent is -67°F to +257°F ±0.5°C accuracy from -10°C to +85°C Thermometer resolution is programmable from 9 to 12 bits Converts 12-bit temperature to digital word in 750 ms (max.) User-definable, nonvolatile temperature alarm settings Alarm search command identifies and addresses devices whose temperature is outside of programmed limits (temperature alarm condition) Applications include thermostatic controls, industrial systems, consumer products, thermometers, or any thermally sensitive system
上傳時(shí)間： 2013-08-04
上傳用戶：CHENKAI
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