【正文】 （ 43） 或 ccvc pqQ ??? （ 44） 式中cP—— 由變配電所供電的月最大有功計(jì)算負(fù)載（ KV） V??—— 月平均負(fù)載率，一般可取 到 之間 1?—— 補(bǔ)償前的功率因數(shù)角，1cos?可取最大負(fù)載時(shí)的 值 2?—— 補(bǔ)償后的功率因數(shù)角，參考電力部門(mén)的要求確定一般可取 到 cq—— 電容補(bǔ)償率 (Kvar/KW),即每千瓦有功負(fù)載需要補(bǔ)償?shù)臒o(wú)功功率，21 tantan ?? ??cq。 電容器組成星形連接時(shí) 32333 10101 3310 ?????? UCCUUUIQC ???? (45) 式中 U —— 裝設(shè)地點(diǎn)電網(wǎng)電壓（ V） cI—— 電容器組的線電壓（ A） ?C —— 每相電容器組的電容量（ F） 考慮到電網(wǎng)電壓的單位常用 KV，cQ的單位為 Kvar，則星形聯(lián)接時(shí)每相電容器的容量為 2310 UQCC cy ?? ??? (46) 式中，yC的單位是 F? 。如果補(bǔ)償電容器補(bǔ)償過(guò)大，可能因電動(dòng)機(jī)慣性轉(zhuǎn)動(dòng)而產(chǎn)生過(guò)電壓，導(dǎo)致電動(dòng)機(jī)損壞。 SVC 主要有并聯(lián)電容器組、可調(diào)飽和電抗器以及檢測(cè)與控制系統(tǒng)三部分組成。 SVC 平滑的動(dòng)態(tài)補(bǔ)償特性是指補(bǔ)充進(jìn)電網(wǎng)的無(wú)功電流是按照電網(wǎng)的無(wú)功需求變化而變化的。靜止無(wú)功發(fā)生器就是典型的一種靜止無(wú)功功率補(bǔ)償裝置。目前研究的熱點(diǎn)主要圍繞改善電路結(jié)構(gòu)、改進(jìn)信號(hào)測(cè)量技術(shù)、尋找更佳的控制方式及濾波等方面。其中，由于無(wú)功電流檢測(cè)的準(zhǔn)確性、快速性關(guān)系到系統(tǒng)性能的好壞，因此專(zhuān)門(mén)對(duì)本文所采用的基于瞬時(shí)無(wú)功功率理論的無(wú)功電流檢測(cè)原理做詳細(xì)介 紹。簡(jiǎn)單地說(shuō)，它的基本原理就是將自換相橋式變流電路23 通過(guò)電抗或直接并聯(lián)到電網(wǎng)上，適當(dāng)?shù)卣{(diào)節(jié)橋式電路交流側(cè)輸出電壓的相位和幅值，或者直接控制其交流側(cè)電流，就可以使該電路吸收或者發(fā)出滿(mǎn)足要求的無(wú)功功率，實(shí)現(xiàn)動(dòng)態(tài)無(wú)功補(bǔ)償?shù)哪康?。總的?lái)看三相電源與負(fù)載間沒(méi)有無(wú)功能量的傳輸 ，各相的無(wú)功量是在三相之間來(lái)回往返的。實(shí)際上考慮到變流電路吸收的電流并不是只有基波，其諧波的存在也多少會(huì)造成總體看來(lái)有少許無(wú)功能量在電源和 SVG 之間往返。靜止無(wú)功發(fā)生器根據(jù)直流側(cè)儲(chǔ)能元件的不同，可以分為電壓型和電流型兩種，結(jié)構(gòu)圖分別如圖43 中 (a)、 (b)所示。 圖 43 不論是電壓型還是電流型結(jié)構(gòu)，其無(wú)功補(bǔ)償?shù)幕驹硎窍嗤ǖ摹Ｏ旅嬉噪妷盒?SVG 系統(tǒng)為例，對(duì)其結(jié)構(gòu)和基本原理進(jìn)行詳細(xì)介紹。因此，當(dāng)僅考慮基波頻率時(shí)， SVG 可以等效視為幅值和相位均可以控制的一個(gè)與電網(wǎng)同頻率的交流 電壓源。所以， SVG 的工作原理就可以用如圖 44 所示的單相等效電路圖來(lái)說(shuō)明。這個(gè)電流就是 SVG 從電網(wǎng)吸收的電流 I. 因此，改變 SVG 的交流側(cè)輸出電壓iU的幅值及其相對(duì)于sU的相位，就可以改變連接電抗上的電壓，從而控制 SVG從電網(wǎng)吸收電流的相位和幅值，也就控制了 SVG 吸收無(wú)功功率的性質(zhì)和大小。在這種情況下，只需使SU和iU同相，僅改變iU的幅值大小即可控制 SVG 從電網(wǎng)吸收的電流 I` 是超前還是滯后 090 ，并且能控制該電流的大小。當(dāng)iU小于sU時(shí)，電流滯后電壓 090 ， SVG吸收感性的無(wú)功功率。 圖 45 在這種情況下，變流器電壓 IU ，與電流 I 仍相差 090` ，因?yàn)樽兞髌鳠o(wú)需有功能量。這個(gè) ? 角也就是變流器電壓 iU ，與電網(wǎng)電壓 sU 的相位差。 本文中對(duì)有功損耗進(jìn)行的補(bǔ)償是通過(guò)直流側(cè)進(jìn)行的。其電流與交流電網(wǎng)電壓的相位差是 090 ，而與變流器交流側(cè)電壓的相位差為 ??090 。這對(duì)于電力系統(tǒng)來(lái)說(shuō)是非常有益的。隨著電力電子技術(shù)的飛速發(fā)展，同步調(diào)相機(jī)、并聯(lián)補(bǔ)償電容器等傳統(tǒng)的無(wú)功功率補(bǔ)償方式已經(jīng)或?qū)⒁媾R淘汰，取而代之的是具有智能化、快速性、準(zhǔn)確性、低諧波含量等優(yōu)點(diǎn)的新一代靜止無(wú)功補(bǔ)償裝置。 （ 1）總結(jié)了電力系統(tǒng)無(wú)功優(yōu)化的各種數(shù)學(xué)模 型及算法，研究了各種算法優(yōu)缺點(diǎn)和適用范圍。 （ 2）簡(jiǎn)單的闡釋了什么是無(wú)功功率，系統(tǒng)的解釋了無(wú)功功率的物理意義，解釋了三相三線電路無(wú)論對(duì)稱(chēng)還是不對(duì)稱(chēng)，含諧波不含諧波，無(wú)功功率都是在三相電路之間流動(dòng)。解釋了無(wú)功功率增加線路損耗的原因。具體地介紹了負(fù)荷水平，電壓水平，電容器投切次數(shù)無(wú)功優(yōu)化的影響。 （ 4）介紹了兩種無(wú)功補(bǔ)償?shù)难b置，傳統(tǒng)的無(wú)功補(bǔ)償電容器和現(xiàn)在常用的靜止無(wú)功發(fā)生器的工作原理，投切方式控制方式。隨著人們對(duì)電網(wǎng)質(zhì)量要求的提高和節(jié)電技術(shù)的發(fā)展，本文還存在需要進(jìn)一步完善的工作 : 無(wú)功優(yōu)化的目標(biāo)函數(shù)應(yīng)進(jìn)一步完善。 目前我國(guó)針對(duì)線損率的分析和節(jié)電技術(shù)的研究相對(duì)落后，并缺乏行之有效的改進(jìn)措施。 總之，在本文的研究基礎(chǔ)上，還可以深入學(xué)習(xí)其它相關(guān)理論和采用先進(jìn)技術(shù)，27 將無(wú)功優(yōu)化和節(jié)電技術(shù)的研究進(jìn)行的更深入，以達(dá)到配電網(wǎng)經(jīng)濟(jì)安全可靠運(yùn)行的目的。t agree with the disciplinary action your employer has taken against you ? your employer dismisses you and you think that you have been dismissed unfairly. For more information about dismissal and unfair dismissal, see Dismissal. You can make a claim to an employment tribunal, even if you haven39。t charge you more than 35% of your pensation if you win the case. If you are thinking about signing up for a damagesbased agreement, you should make sure you39。s antiracism taskforce, is in London for the Football Association39。s Premier League match at Chelsea on Sunday. I am going to be at the match tomorrow and I have asked to meet Yaya Toure, he told BBC Sport. For me it39。s 21 win. Michel Platini, president of European football39。s actions. CSKA said they were surprised and disappointed by Toure39。 May be back in the past, to oneself the paranoid weird belief disillusionment, these days, my mind has been very messy, in my mind constantly. Always feel oneself should go to do something, or write something. Twenty years of life trajectory deeply shallow, suddenly feel something, do it. 一字開(kāi)頭的年齡已經(jīng)到了尾聲?？傆X(jué)得自己自己似乎應(yīng)該去做點(diǎn)什么，或者寫(xiě)點(diǎn)什么。 The end of our life, and can meet many things really do? 而窮 盡我們的一生，又能遇到多少事情是真正地非做不可？ During my childhood, think lucky money and new clothes are necessary for New Year, but as the advance of the age, will be more and more found that those things are optional。t really grow up, it seems is not so important。t want to give vent to out your inner voice can be in the high school children of the feelings in a period, but was eventually infarction when graduation party in the throat, later again stood on the pitch he has sweat profusely, looked at his thrown a basketball hoops, suddenly found himself has already can39。 Originally, this world, can produce a chemical reaction to an event, in addition to resolutely, have to do, and time. 原來(lái)，這個(gè)世界上，對(duì)某個(gè)事件能產(chǎn)生化學(xué)反應(yīng)的，除了非做不可的堅(jiān)決，還有，時(shí)間。s time, your ideas are always special to clear. Want, want, line is clear, as if nothing could shake his. Also once seemed to be determined to do something, but more often is he backed out at last. Dislike his cowardice, finally found that there are a lot of love, there are a lot of miss, like shadow really have been doomed. Those who do, just green years oneself give oneself an arm injection, or is a selfrighteous spiritual. 一個(gè)人的時(shí)候，自己的想法總是特別地清晰。也曾經(jīng)好像已經(jīng)下定了決心去做某件事，但更多的時(shí)候是最后又打起了29 退堂鼓。那些曾經(jīng)所謂的非做不可，只是青蔥年華里自己給自己注射的一支強(qiáng)心劑，或者說(shuō)，是自以為是的精神寄托罷了。 Those were broken into various shapes of stationery。 Have declared the end of the encounter that haven39。突然想到那件藍(lán)格子襯衫；那些被折成各種各樣形狀的信紙；那段從街角深巷伊始的友誼；還有那場(chǎng)還沒(méi)有開(kāi)始就宣告了終結(jié)的 邂逅計(jì)劃 …… 那些年那些天的非做不可，終于和青春一樣，都將在我們的人生中謝幕。ll be traveling fast, so despite the distance, it will not be like diving into the deep end of a pool. It will be like he is diving into the shallow end. Skydiver preps for the big jump 30 When he jumps, he is expected to reach the speed of sound 690 mph (1,110 kph) in less than 40 seconds. Like hitting the top of the water, he will begin to slow as he approaches the more dense air closer to Earth. But this will not be enough to stop him pletely. If he goes too fast or spins out of control, he has a stabilization parachute that can be deployed to slow him down. His team hopes it39。t. Baumgartner still will free fall at a speed that would cause you and me to pass out, and no parachute is guaranteed to work higher than 25,000 feet (7,620 meters). cause there