【正文】 表11工廠負(fù)荷情況表車間名稱設(shè)備容量(Kw)需要系數(shù)功率因素鍛工車間38紡紗車間350制條車間88軟水站88合計(jì)826高壓側(cè)合計(jì)826機(jī)修車間300倉(cāng)庫(kù)40辦公室21外文資料翻譯Protection relayMicrouterbased Rlaying A newer development in the of power system protection is the of puters (usually microputers) for relaying. Although puters provide the same protection as that supplied by conventional relays, there are some advantages to the use of puterbased relaying. The logic capability and application expansion possibilities for puterbased relaying is much greater than for electromechanical devices. Computerbased relaying samples the values of the current, voltage, and other items covered in the protection scheme several times a second, and by use of A/D converters, change these analog values to digital form and then send them to the puter. In the event of a fault, the puter can calculate the fault’s current values and characteristics, and settings can be changed merely by reprogramming. Computerbased relaying are also capable of locating faults, which has been one of the most popular features in their application. In addition, selfchecking features can be built in and sequence of events information can be downloaded to remote puters for fast analysis of relaying operations. Computerbased relying system consists of subsystems with well defined functions. Although a specific subsystem may be different in some of its details, these subsystems are most likely to be incorporated in its design in some form. The block diagram in Figure 131 shows the principal subsystems of a puterbased relaying. The processor is the center of its organization. It is responsible for the execution of relaying programs, maintenance of various timing functions, and municating with its peripheral equipment. Several types of memories are shown in Figure 131─each of them serves a specific need. The Random Access Memory (RAM) holds the input sample data as they are brought in and processed. The Read Only Memory (ROM) or Programmable Read Only Memory (PROM) is used to store the programs permanently. In some cases the programs may execute directly form the ROM if its read time is short enough. If this is not the case, the programs must be copied form the ROM into the RAM during an initialization stage, and then the realtime execution would take place form the RAM. The Erasable PROM (EPROM) is needed for storing certain parameters (such as the relaying settings) which may be changed form time to time, but once it is set it must remain fixed even if the power supply to the puter is interrupted. The relaying inputs are currents and voltages─or, to a lesser extent─digital signals indicating contact status. The analog signals must be converted to voltage signals suitable for conversion to digital form. The current and voltage signals obtained form current and voltage transformer secondary windings must be restricted to a full scale value of 177。此斷路器配備有定時(shí)限過電流保護(hù)和電流速斷保護(hù)。二級(jí)負(fù)荷也屬于重要負(fù)荷。在感嘆老師淵博的學(xué)術(shù)理論知識(shí)及豐富的實(shí)踐經(jīng)驗(yàn)的同時(shí)，我也看到了老師嚴(yán)謹(jǐn)?shù)闹螌W(xué)態(tài)度和一絲不茍的敬業(yè)精神，這些都將使我終身受益。這一學(xué)期的畢業(yè)設(shè)計(jì)，由于本人個(gè)人水平限制原因，我對(duì)這個(gè)設(shè)計(jì)還不是很深入，論文本身還存在諸多欠妥之處，懇請(qǐng)老師給我提出寶貴的意見，只有發(fā)現(xiàn)問題面對(duì)問題才能解決問題，不足和遺憾不會(huì)給我打擊指揮更好的鞭策我前行，今后我更會(huì)關(guān)注新技術(shù)新設(shè)備新方案的出現(xiàn)，并爭(zhēng)取盡快的掌握這些先進(jìn)的知識(shí)，保持“不放棄努力本是我的任務(wù)，在現(xiàn)在的基礎(chǔ)上爭(zhēng)取更是我的職責(zé)。變壓器室有兩條接地干線、高低壓配電室各有一條接地干線與室外公共接地裝置焊接相連。主變壓器主要靠此避雷器來(lái)防護(hù)雷電侵入波的危害。避雷針采用直徑20mm的鍍鋅圓鋼，避雷帶采用25mm4mm的鍍鋅扁鋼。避雷器應(yīng)與被保護(hù)設(shè)備并聯(lián)，裝在被保護(hù)設(shè)備的電源側(cè)。接閃的金屬線稱為避雷線，或稱架空地線。低壓母線的選擇10kV母線選擇LMY3(404), 380V母線選LMY3（12010）+806。 車間變電所。（電流比為300/5）,低壓斷路器DZ20400/3。食堂車間出線的最大負(fù)荷電流為57A，（電流比為60/5），低壓斷路器為DZ20100/3。所以選擇低壓斷路器DW151500,低壓刀開關(guān)HD131500/30，（電流比為1500/5）均滿足負(fù)荷電流的要求。，（電流比為300/5），低壓斷路器為DZ20400/3。,（電流比為150/5）,低壓斷路器DZ20200/3。該車間變電所下屬鍛工車間、紡紗車間、制條車間、軟水站。 低速斷路器（如油斷路器），；高速斷路器（如真空斷路器）。 t—開關(guān)的熱穩(wěn)定試驗(yàn)時(shí)間，單位為s； —開關(guān)所在處的三相短路穩(wěn)態(tài)電流，單位為kA。即 （61） (2)按工作電流選擇 設(shè)備的額定電流不應(yīng)小于所在電路的計(jì)算電流。(2)按短路條件包括動(dòng)動(dòng)穩(wěn)定性和熱穩(wěn)定性進(jìn)行校驗(yàn)。對(duì)于工廠供電系統(tǒng)來(lái)說，由于將電力系統(tǒng)當(dāng)作無(wú)限大容量電源，而且短路電路也比較簡(jiǎn)單，因此一般只需采用阻抗串、并聯(lián)的方法即可將電路化簡(jiǎn)，求出其等效總阻抗。在計(jì)算電路圖上，將短路計(jì)算所考慮的各元件的額定參數(shù)都表示出來(lái)，并將各元件依次編號(hào)，然后確定短路計(jì)算點(diǎn)。饋電給倉(cāng)庫(kù)用BLV鋁芯聚氯乙烯絕緣導(dǎo)線。C，一次查表，初選纜芯截面為的交聯(lián)聚乙烯絕緣鋁芯電纜（該型電纜最小芯線截面積為），其，滿足發(fā)熱條件。因此YJL2210000325電纜滿足短路熱穩(wěn)定條件。(2)校驗(yàn)機(jī)械強(qiáng)度 查表得最小允許截面，因此按發(fā)熱條件的LJ50滿足機(jī)械強(qiáng)度要求。電氣主接線詳見附錄1。母線分段后可進(jìn)行分段檢修，對(duì)于重要用戶，可以從不同段引出兩個(gè)回路，當(dāng)一段母線發(fā)生故障時(shí)，由于分段斷路器QF1在繼電保護(hù)作用下自動(dòng)將故障段迅速切除，從而保證了正常母線段不間斷供電和不致使重要用戶停電。這就是隔離開關(guān)與斷路器配合操作的原則。 主接線的選擇 單母線接線方式單母線也稱匯流排，即匯集和分配電能的硬導(dǎo)線?？煽浚簼M足各級(jí)負(fù)荷的不中斷供電要求。需在低壓側(cè)并聯(lián)電容器的容量為： 根據(jù)各種數(shù)據(jù)，我選定并聯(lián)電容器的型號(hào)為： 所以 個(gè)數(shù)應(yīng)該是3的倍數(shù)。 圖11 無(wú)功補(bǔ)償向量圖圖11率因數(shù)提高與無(wú)功功率和視在功率變化的關(guān)系。它具有投資省，裝設(shè)地點(diǎn)不受自然條件限制，運(yùn)行簡(jiǎn)便可靠等優(yōu)點(diǎn)。如在充分發(fā)揮設(shè)備潛力、改善設(shè)備運(yùn)行性能、提高其自然功率因數(shù)的情況下，尚達(dá)不到規(guī)定的工廠功率因數(shù)要求。5．變壓器型號(hào)的選擇根據(jù)負(fù)荷計(jì)算結(jié)果表11確定各車間變電所變壓器型號(hào)。4．變壓器臺(tái)數(shù)的選擇該工廠引用10kV進(jìn)線，下分五個(gè)車間變電所，每個(gè)變電所都可以采用一臺(tái)或者兩臺(tái)變壓器。暗備用方式運(yùn)行時(shí)，變壓器的容量為70%S﹥50%S，滿足條件2；其負(fù)荷率為50%S/70%S≈70%,負(fù)荷率大于68%，滿足條件3。故：（1） （122）（2） （123） （3） （124） （4）總的計(jì)算電流為 （125）根據(jù)上面公式進(jìn)行負(fù)荷計(jì)算有功損耗： 無(wú)功損耗： （126）： =： ： ： ： 高壓母線上所有高壓配電線路計(jì)算負(fù)荷之和： =根據(jù)計(jì)算可得表11表11工廠負(fù)荷統(tǒng)計(jì)表車間名稱設(shè)備容量(kW)需要系數(shù)功率因素計(jì)算負(fù)荷（kW）（kvar）（kVA）（A）車變鍛工車間38紡紗車間35028021035制條車間88280210350軟水站88合計(jì)826損耗高壓側(cè)合計(jì)826車變機(jī)修車間30090180倉(cāng)庫(kù)401224辦公室21合計(jì)361損耗高壓側(cè)合計(jì)361織工車間450360270450染工車間400320240400