斯坦福發(fā)電機簡介

康明斯發(fā)電機技術(shù)（中國）有限公司（原無錫新時代交流發(fā)電機有限公司）是康明斯發(fā)電機技術(shù)系統(tǒng)在中國的唯一的獨資企業(yè)，首期投資1760萬美元。成立于1996年2月，于1997年11月正式開業(yè)。目前年生產(chǎn)能力為65,000臺發(fā)電機。

康明斯發(fā)電機技術(shù)系統(tǒng)有50多年成功地滿足顧客需要的經(jīng)驗，是世界交流發(fā)電機技術(shù)的先導(dǎo)，康明斯發(fā)電機技術(shù)系統(tǒng)擁有全球銷售和服務(wù)網(wǎng)絡(luò)，并在英國、美國、中國、印度有生產(chǎn)工廠。無錫工廠完全按照康明斯發(fā)電機技術(shù)系統(tǒng)的設(shè)計及工藝標準來制造斯坦福交流發(fā)電機。產(chǎn)品設(shè)計、材料、生產(chǎn)、試驗均由英方人員直接管理控制。體積小，重量輕，技術(shù)先進，性能可靠是斯坦福發(fā)電機的重要特性。

康明斯發(fā)電機技術(shù)系統(tǒng)制造的斯坦福發(fā)電機可與世界上所有柴油機配套，如康明斯、帕金斯、VOLVO、MTU、道依茨、卡特彼勒和國產(chǎn)95、130、135、150、190系列等柴油機。各系列產(chǎn)品成功供應(yīng)發(fā)電機組成套廠家，廣泛應(yīng)用于鐵路、船舶、郵電通信、軍工、油田、交通、高層建筑及冷藏集裝箱等領(lǐng)域。

康明斯發(fā)電機技術(shù)系統(tǒng)所生產(chǎn)的發(fā)電機系列為:BC16、BC18、UC224、UC274、HC4、HC5、LV6、HC7。功率范圍為:6.5KW－2000KW。HC系列的發(fā)電機為無刷旋轉(zhuǎn)磁場結(jié)構(gòu)，電壓最高達660V/50HZ或60HZ，滿足BS5000標準第三部分和其他國際標準。在HC4,HC5,HC6/LV6,HC7四個機座號中，200KW-2000 KW范圍內(nèi)，可選1500rpm(50HZ)或1800rpm（60HZ）、4極的發(fā)電機。在HC6/LV6和HC7兩個機座號中，224KW-1300KW范圍內(nèi)，可選1000rpm（50HZ）或1200rpm(60HZ)、6極的發(fā)電機。機座號位HC4和HC5的發(fā)電機，其勵磁系統(tǒng)可為使用AS440或SX421AVR的定子供電或為使用MX341或MX321AVR的永磁發(fā)電機（PMG）勵磁，機座號位HC6/LV6和HC7的發(fā)電機使用MX341或MX321AVR的永磁發(fā)電機（PMG）勵磁系統(tǒng)。

自勵A(yù)VR控制的發(fā)電機，主機定子通過AS440（或SX421）AVR為勵磁機磁場提供勵磁源，AVR是調(diào)節(jié)勵磁機磁場勵磁電流的控制裝置。AVR根據(jù)來自主機定子繞組的電壓感應(yīng)信號作出反饋，通過控制低功率的勵磁機磁場調(diào)節(jié)勵磁機電樞的整流輸出功率，從而達到控制主機磁場電流的要求。AS440AVR通過感應(yīng)兩相平均電壓，確保較高的電壓調(diào)整率，除此之外，它還監(jiān)測發(fā)動機的轉(zhuǎn)速，如低于預(yù)選轉(zhuǎn)速（HZ）設(shè)定，則相應(yīng)降低輸出電壓，以防止發(fā)動機低速時的國力，緩減加載時的沖擊，以減輕發(fā)動機的負擔(dān)。SX421除了AS440的特點外，還具有三相均方根感應(yīng)的特點，在與外部斷路器（裝在開關(guān)板上）一起使用時，它還提供過電壓保護。

永磁發(fā)電機（PMG）勵磁發(fā)電機通過MX341(或321)AVR為勵磁機提供勵磁源，AVR是調(diào)節(jié)勵磁機勵磁電流的控制裝置。如果是MX321AVR，則通過一個隔離變壓器向來自主機定子繞組的電壓感應(yīng)信號作出反饋，通過控制低功率的勵磁機磁場，調(diào)節(jié)勵磁機電樞的整流輸出功率，從而達到控制主機磁場電流的要求。PMG系統(tǒng)提供一個與定子負載無關(guān)的恒定的勵磁電源，提供較高的電動機啟動承受能力，并不受非線性負載（例如可控硅直流電動機）產(chǎn)生的主機定子輸出電壓的波形畸變的干擾。MX341AVR通過檢測二相平均電壓來確保較高電壓的調(diào)整率，另外它還檢測發(fā)動機轉(zhuǎn)速，如低于預(yù)選的轉(zhuǎn)速設(shè)定，則相應(yīng)降低輸出電壓，以防止發(fā)動機低速時的過勵，緩減加載時的沖擊，以減輕發(fā)動機的負擔(dān)。它還提供延時的過勵保護，在勵磁機磁場電壓過高的情況下對發(fā)電機滅磁。MX321除提供MX341巨友的保護發(fā)動機的減荷特性外，還具有三相均方根檢測和過電壓保護的特點。

STAMFORD 發(fā)電機是按照國際最高質(zhì)量標準,配備精心選擇的零部件,采用先進的世界級工藝制造而成。其能適應(yīng)惡劣環(huán)境的全H級絕緣和最佳效率設(shè)計的繞組尤其適合于特殊場合的應(yīng)用,標準的12個可重接出線頭確保滿足各種電壓要求。國際品牌、人性化設(shè)計和一流服務(wù)使STAMFORD擁有眾多的終身客戶和廣闊的應(yīng)用領(lǐng)域。

     

斯坦福發(fā)電機(SX440 460 321 341 AVR)故障維修查找

1、機組起始時無電壓：

a、檢查線路 K1--K2

b、檢查轉(zhuǎn)速

c、檢查剩磁電壓，按外界勵磁試驗法步驟檢查發(fā)電機和 AVR（在機靜止時拆下 AVR上的 X和 XX的連線啟動機組并測試 P2-P3，停機重新接上 X和 XX導(dǎo)線，如果測得電壓大于 5V則發(fā)電機應(yīng)能正常工作，低于 5V用一個直流電池負極接 XX線柱，正極通過一個二極管接 X線柱。二極管為 1A／1000V，起機 P2-P3間應(yīng)有 170-250V電壓，拆下電池后仍無電壓查找繞組 AVR和旋轉(zhuǎn)二極管。查找永磁發(fā)電機 PMGP2P3P4間電壓應(yīng) 170-180V／50HZ，200-216V／60HZ，若不均衡，停機從非驅(qū)動端將 PMG輸出導(dǎo)線插件斷開，檢查 P2P3P4連線測定子電阻應(yīng)在 2.3Ω±10％，否則定子不行，若電壓均衡但電壓偏低阻值正常，轉(zhuǎn)子應(yīng)更換）。

 

2、空載或負載時電壓不穩(wěn)

a、檢查轉(zhuǎn)速穩(wěn)定性

b、檢查穩(wěn)定性設(shè)置（順時到底逆時到開始電壓波動再順時針一

點到平穩(wěn)）

 

3、空載或負載時電壓過高

a、檢查轉(zhuǎn)速

b、檢查發(fā)電機負載是否容性負載（功率因數(shù)超前）

 

4、空載時電壓過低

c、檢查轉(zhuǎn)速

d、檢查接線 1-2或外接手動微調(diào)是否連接完好

 

5、負載時電壓過低

a、檢查轉(zhuǎn)速

b、檢查 UFRO設(shè)置（檢查發(fā)動機和 AVR）

電動機故障

1、電機不能啟動： a、缺相 b、熔體燒斷 c、繞組接地或相間匝間短路

2、電機外殼帶電： a、繞組接地 b、繞組受潮，絕緣老化

3、電機運行時，電流表指針不穩(wěn)擺動： a、轉(zhuǎn)子導(dǎo)條開焊或斷條

4、絕緣電阻低： a、繞組受潮或被水淋濕 b、繞組絕緣沾滿灰塵油污 c、引出線絕緣老化破裂

d、繞組絕緣老化

5、電動機運行時有雜音、不正常： a、軸承磨損有故障 b、定轉(zhuǎn)子鐵芯松動 c、繞組有故障（如短路） d、軸承缺少潤滑脂 e、定轉(zhuǎn)子相擦或較大的砂粒進入氣隙 f、系統(tǒng)轉(zhuǎn)動慣量小

6、電機過熱或冒煙： a、氣隙中積滿灰塵 b、電機內(nèi)外積滿塵土或異物影響電機散熱 c、導(dǎo)條斷裂或開焊 d、繞組匝間短路或接地 e、電機兩相運轉(zhuǎn)

7、電動機振動： a、軸承磨損 b、導(dǎo)條斷裂開焊 c、繞組故障（短路斷路接地等） d、鐵芯變形或松動 e、皮帶輪安裝不當(dāng) f、電機地腳螺栓松動

8、軸承發(fā)熱超過規(guī)定值： a、潤滑脂過多或過少 b、油質(zhì)不好或含雜質(zhì) c、軸承有故障，磨損，有雜物等 d、皮帶輪偏小或皮帶過緊 e、軸承油隙過大或過小

㈡電路保險絲熔斷：更換保險絲。

多臺柴油發(fā)電機組并機并網(wǎng)運行的優(yōu)缺點與發(fā)電機并網(wǎng)解裂系統(tǒng) 一．發(fā)電機組并列運行的條件是什么？

發(fā)電機組投入并列運行的整個過程叫做并列。將一臺發(fā)電機組先運行起來，把電壓送至母線上，而另一臺發(fā)電機組啟動后，與前一臺發(fā)電機組并列，應(yīng)在合閘瞬間，發(fā)電機組不應(yīng)出現(xiàn)有害的沖擊電流，轉(zhuǎn)軸不受到突然的沖擊。合閘后，轉(zhuǎn)子應(yīng)能很快的被拉入同步。（即轉(zhuǎn)子轉(zhuǎn)速等于額定轉(zhuǎn)速）因此發(fā)電機組并列必須具備以下條件：
 1.發(fā)電機組電壓的有效值與波形必須相同.
 2.兩臺發(fā)電機電壓的相位相同.
 3.兩臺發(fā)電機組的頻率相同.
 4.兩臺發(fā)電機組的相序一致.

二、什么叫發(fā)電機組的準同期并列法？怎樣進行同期并列？

　　準同期就是準確周期。用準同期法進行并列操作，發(fā)電機組電壓必須相同，頻率相同以及相位一致，這可通過裝在同期盤上的兩塊電壓表、兩塊頻率表以及同期表和非同期指示燈來監(jiān)視，并列操作步驟如下：
　將其中一臺發(fā)電機組的負荷開關(guān)合上，將電壓送至母線上，而另一臺機組處在待并狀態(tài)。

　　合上同期開頭，調(diào)節(jié)待并發(fā)電機組的轉(zhuǎn)速，使它等于或接近同步轉(zhuǎn)速（與另一臺機組的頻率相差在半個周波以內(nèi)），調(diào)節(jié)待并發(fā)電機組的電壓，使其與另一臺發(fā)電機組電壓接近，在頻率與電壓均相近時，同期表的旋轉(zhuǎn)速度是越來越慢的，同期指示燈也時亮?xí)r暗；當(dāng)待并機組與另一臺機組相位相同時，同期表指針指示向上方正中間位置，同期燈最暗，當(dāng)待并機組與另一臺機組相位差最大時，同期表指向下方正中位置，此時同期燈最亮，當(dāng)同期表指針按順時針方向旋轉(zhuǎn)時，這說明待并發(fā)電機的頻率比另一臺機組的頻率高，應(yīng)降低待并發(fā)電機組的轉(zhuǎn)速，反之當(dāng)同期表指針按逆時針方向旋轉(zhuǎn)時，應(yīng)增加待并發(fā)電機組的轉(zhuǎn)速。當(dāng)同期表指針順時針方向緩慢旋轉(zhuǎn)，指針接近同期點時，立即將待并機組的斷路器合閘，使兩臺發(fā)電機組并列。并列后切除同期表開關(guān)和相關(guān)的同期開關(guān)。

三、在進行發(fā)電機組的準同期并列時，應(yīng)注意什么？

　　準同期并列是手動操作，操作是否順利與運行人員的經(jīng)驗有很大的關(guān)系，為防止不同期并列，下列三種情況不準合閘。

1.當(dāng)同期表指針出現(xiàn)跳動現(xiàn)象時，不準合閘，因為同期表內(nèi)部可能有卡帶現(xiàn)象，反映不出正確的并列條件。

2.當(dāng)同期表旋轉(zhuǎn)過快時，說明待并發(fā)電機組與另一臺發(fā)電機 組的頻率相差太大，由于斷路器的合閘時間難以掌握，往往使斷路器不在同期點合閘，所以此時不準合閘。

3.如果同期表指針停在同期點上不動，止時不準合閘。這是因為斷路器在合閘過程中如果其中一臺發(fā)電機組的頻率突然變動，就有可能使斷路器正好合在非同期點上。

四、怎樣調(diào)整并列機組的逆功現(xiàn)象？

當(dāng)兩臺發(fā)電機組空載并列后，會在兩臺機組之間，產(chǎn)生一個頻率差與電壓差的問題。并且在兩臺機組的監(jiān)視儀表上（電流表、功率表、功率因數(shù)表），反應(yīng)出實際的逆功情況，一種是轉(zhuǎn)速（頻率）不一致造成的逆功，另一種是電壓不等造成的逆功，其調(diào)整如下：

1．頻率造成逆功現(xiàn)象的調(diào)整：

如果兩臺機組的頻率不等，相差較大時，在儀表上（電流表、功率表）顯示出，轉(zhuǎn)速高的機組電流顯示正值，功率表指示為正功率，反之，電流指示負值，功率指示負值。這時調(diào)整其中一臺機組的轉(zhuǎn)速（頻率），視功率表的指示進行調(diào)整，把功率表的指示調(diào)整為零即可。使兩臺機組的功率指示均為零，這樣兩臺機的轉(zhuǎn)速（頻率）基本上一致。但是，這時電流表仍有指示時，這就是電壓差造成的逆功現(xiàn)象了。

2．電壓差造成逆功現(xiàn)象的調(diào)整：

當(dāng)兩臺機組的功率表指示均為零時，而電流表仍然有電流指示（即一反一正指示）時，可調(diào)整其中一臺發(fā)電機組的電壓調(diào)整旋鈕，調(diào)整時，視電流表與功率因數(shù)的指示進行。將電流表的指示消除（即調(diào)整為零），電流表無指示后，這時視功率因數(shù)表的指示，把功率因數(shù)調(diào)至滯后0.5以上即可.一般可調(diào)整至0.8左右,為最佳狀態(tài)。

五、發(fā)電機保護回路

1．逆功

逆功現(xiàn)象是由發(fā)電機組轉(zhuǎn)速（頻率）及電壓不同而造成的，即一臺發(fā)電機組帶正功，而另一臺機組帶負功率。也就是說帶負功率的機組，這時變成了一個負載（此機組頻率低，轉(zhuǎn)速不一致的現(xiàn)象）。電壓不相同時，電壓高的機組，向電壓低的機組，提供一個無功電流與無功電壓（此機組的電流表正向指示），相當(dāng)于在本供電系統(tǒng)內(nèi)，加了一個調(diào)相機組。電壓低的機組，這時成為一個大的負載，接受一個很大的無功電流，來維持兩臺機組的電壓平衡（此機組的電流表反向指示）。監(jiān)測時把某一臺機組的電壓調(diào)高，或?qū)⒘硪慌_機組電壓高低，造成一臺機組有逆功電流，其動作電流為額定電流20%左右。逆動繼電器動作、跳閘、報警，但不停機。

2．過電流：

現(xiàn)在的發(fā)電機組額定功率一定的，它的超載能力很低，基本上在額定功率的5%左右，允許帶載時間15~30分鐘，最多不超60分鐘，超過這個時間，發(fā)電機組會發(fā)熱，導(dǎo)線絕緣會降低，也就降低了使用壽命。所以在設(shè)定過電流保護時無特殊要求的，過電流保護設(shè)定在額定電流的110%即可。帶載測試時，將電流帶至額定流的110%，過流繼電器動作。跳閘、報警、不停機。

3．過電壓：

在并列使用發(fā)電機組時最怕供電系統(tǒng)發(fā)生振蕩，一但發(fā)生振蕩系統(tǒng)電壓升高，易造成用電設(shè)備及供電設(shè)備的絕緣擊穿，使供電設(shè)備與用電設(shè)備一起癱瘓。為此并列使用的發(fā)電機組均裝有過電壓保護，其設(shè)定值為額定電壓的105%為最佳。短接過電壓繼電器，跳閘停機、報警動作。（六）分合閘回路

分、合閘回路均接入手機并列，自動并列的控制回路。

1．手動分合閘：每臺機組均可做為首機或待并分、合閘使用，在手動并車或供電時，使用手動分合閘。

2．自動分合閘：每臺機組均可選擇為待并機組，或首臺機組；首機機組自啟動后，合閘回路自動合閘，自動投入及退出同期。同期后把待并機組自動合閘并列運行。

3．無論是手動合閘，還是自動合閘，一旦機組出現(xiàn)逆功，過了低油壓、高水溫、高水溫、高油溫、過電壓，全部自動分閘解列與負載脫離。

（七）同期回路

1．當(dāng)首機合閘后把電源送至母線，這時母線檢測同期回路，與待并機的同期回路，接到信號后，自動合上同期檢測繼電器。將母線電壓與待并機電壓送至同期控制模塊，模塊自動檢測，并列機組的電壓與轉(zhuǎn)速。如果轉(zhuǎn)速有差別時，同期模塊自動調(diào)整待并機轉(zhuǎn)速，使其達到并列條件。找到同期點后同期模塊發(fā)出合閘指令，待并機組接到指令后執(zhí)行合閘，即兩臺機組并列運行。

2．機組并列后，同期回路自動退出工作狀態(tài)，但必須人為的把自動同期的轉(zhuǎn)換開關(guān)退出，防止來電后在解列時，待并機組又接到并列信號，將同期裝置自動投入，使機組再次并列。

（八）負載分配

1．單機運行時，負載分配器不投入工作。

2．機組并列后每臺機組的負載分配器，同時投入工作，各自調(diào)整自已的轉(zhuǎn)速，使其兩臺機組的功率平均分配，其工作原理，就是根據(jù)本機組的輸出功率的大?。措娏鞯拇笮。詣诱{(diào)整丁機組的轉(zhuǎn)速，使其負載平衡。

（九）電壓調(diào)整回路：

1．機組并列前，必須把兩臺機組的電壓調(diào)整在同一數(shù)值上。

2．空載并列后，調(diào)整電壓旋鈕，把逆功現(xiàn)象消除，使其功率因數(shù)在滯后0.8左右即可。

3．并列機組帶載后，可根據(jù)負載情況，手動調(diào)節(jié)電壓調(diào)整旋鈕，使其功率因數(shù)在最佳位置，以后可不用再調(diào)整。

（十）速度調(diào)整回路：

1．并列前必須把兩機組的速度（頻率）調(diào)整一致。

2．并列時，可根據(jù)同期表的轉(zhuǎn)動速度，調(diào)節(jié)首機或待并機組的轉(zhuǎn)速，使同期表轉(zhuǎn)動方向，按順時針或逆時針方向轉(zhuǎn)動，速度越慢越好，但同期表的指針必須轉(zhuǎn)動才能并列。

3．并列后，觀察兩臺機組的電流、功率是否平衡，如差別太大，可調(diào)整速度旋鈕，將兩臺機組的功率調(diào)整到一致。

（十一）儀表檢測回路：

1．操作前，必須把各種相關(guān)的儀表調(diào)改至零，但功率因數(shù)表與頻率表不在零處。

2．操作時，觀察各種儀表的運行狀態(tài)，是否符合規(guī)定（有無儀表接線接反的現(xiàn)象）。

3．電流、電壓、要使用有關(guān)儀表與之檢驗一下，看指示數(shù)值是否正常。

（十二）啟動回路：

1．操作前必須首先檢查啟動回路是否正常。

2．啟動后相關(guān)元件是否能夠正常工作。

3．啟動機與主機的結(jié)合是否正常，能否退出。

（十三）停機回路：

1．停機電磁鐵與電磁閥動作是否可靠。

2．在機組發(fā)生故障時，是否自動停機。

3．手動停機回路是否完善。

4．只需跳閘時，是否停機等現(xiàn)象。

Standford generator.

Cummings generator technology (China) Co., Ltd. (formerly Wuxi new era of AC generator Company Limited ) is the Cummings generator technology system in China as the sole proprietorship, the first phase investment of 17600000dollars. Was established in 1996February, in 1997November officially opened. The current annual production capacity of65000 generators.

Cummings generator technologies has more than 50 years successfully meet the needs of the customer experience, is the world leader of AC generators technology, Cummings generator technologies has a global sales and service network, and in the UK, the United States, China, has production plants in India. Wuxi factory in full accordance with Cummings generator technology system design and process standard to make Standford AC generator. Product design, materials, production, test are under direct control of the personnel. Small volume, light weight, advanced technology, reliable performance is an important characteristic of Standford turbine.

Cummings generator technology system manufactured by Standford generator can be with all the world's diesel engine matching, such as Cummings, Perkins, VOLVO, MTU, DEUTZ, caterpillar and made 95,130,135,150,190series diesel engine. The series of products successfully supply generator sets manufacturers, widely used in railway, shipping, telecommunications, military, oil, transport, high-rise buildings and areas such as refrigerated containers.

Cummings generator technologies produced by the generator series : BC16, BC18, UC224, UC274, HC4, HC5, LV6, HC7. Power range:6.5KW2000KW. HC series generators for brushless rotary magnetic field structure, the voltage up to 660V/50HZ or 60HZ, to meet the BS5000standard third parts and other international standards. In HC4, HC5, HC6/LV6, HC7, four model,200KW-2000KW range, optional 1500rpm (50HZ ) or 1800rpm (60HZ ),4 pole generator. In HC6/LV6and HC7two model, the range of 224KW-1300KW, optional 1000rpm (50HZ ) or 1200rpm (60HZ ),6 pole generator. The base number of a HC4and the HC5 generator, the excitation system can use AS440 or SX421AVR stator power supply or for the use of MX341or MX321AVR permanent magnet generator ( PMG ) excitation, the base number of a HC6/LV6and the HC7 generator using MX341 or MX321AVR permanent magnet generator ( PMG ) excitation system.

Self control AVR generator stator, the host through AS440( or SX421) AVR exciter field provides the excitation source, AVR is the regulation of exciter field excitation current control device. From the host AVR according to stator winding voltage sensing signal feedback, by controlling the low power of the exciter field adjusting armature excitation rectifier output power, so as to control the host magnetic current requirements. AS440AVR through the induction phase average voltage, ensure high voltage regulation rate, in addition, it also monitors the speed of the engine, such as lower than a preselected speed ( HZ ) setting, is correspondingly lower output voltage, to prevent the engine at low speed and strength, reduce the impact load, in order to reduce the burden of engine. SX421in addition to AS440features, but also has three phase RMS sensing characteristics, in contact with the external circuit breaker ( installed in the switch board ) when used together, it also provides overvoltage protection.

Permanent magnet generator ( PMG ) excitation generator through MX341( or 321) AVR exciter provides excitation source, AVR is the regulation of exciter field current control device. If it is MX321AVR, through an isolation transformer to from the main stator winding voltage sensing signal feedback, by controlling the low power of the exciter magnetic field, adjusting armature excitation rectifier output power, so as to control the host magnetic current requirements. The PMG system provides a stator is independent of the load with constant power excitation, provide higher motor starting capacity, is not affected by nonlinear load ( e.g. silicon controlled DC motor ) produced by the host in the stator output voltage waveform distortion disturbance. MX341AVR by detecting the phase average voltage to ensure higher voltage regulation rate, and it also detects the rotation speed of the engine, such as less than a preselected speed setting, the corresponding output voltage is reduced, to prevent the engine at low speed of over excitation, reducing load impact, in order to reduce the burden of an engine. It also provides delay over excitation protection, the exciter field high voltage of generator. MX321provides a MX341friends of the giant engine protection of load reduction characteristics, but also has three phase RMS detection and overvoltage protection characteristic.

The STAMFORD generator is in accordance with the highest international quality standards, with careful selection of components, the use of advanced world class manufacturing process is made. It can adapt to bad environment the whole class H insulation and optimal design of winding efficiency is especially suitable for special applications, the standard 12reclosable outlet head to ensure that meet the requirements of various voltage. International brand, the humanized design and first-class service make STAMFORD has many customers for life and wide application area.

A plurality of diesel generator and grid to run the advantages and disadvantages and generator cracking system

A generating set parallel operation conditions?

Generating units put into operation in parallel of the whole process is called the. A generator to run, the voltage into a bus, while the other units after the start, with a generating set parallel, in the closing moments, generator should not appear detrimental impact on current, the rotating shaft is not affected by the sudden impact. After closing, the rotor can be quickly pulled into synchronization. (i.e., the rotational speed of the rotor is equal to the rated speed ) thus generating set parallel must meet the following conditions:

1generator voltage effective value and waveform must be the same.

2two generator voltage phase difference.

3two generating units of the same frequency.

4two generating units of the sequence.

Two, what is the generator quasi synchronization method? How to carry out the corresponding parallel?

Quasi synchronization is accurate cycle. Using quasi synchronization method for parallel operation, generator voltage must be the same, the same frequency and phase, which can be installed in the same period through the disc on two pieces of voltage meter, two frequency table and corresponding table and non synchronous indicating lamp to monitor, the operation steps are as follows:

Which will be of a generating unit load switch is closed, the voltage into a bus, while the other units in the standby state.

Close period beginning, adjusting to and turbine speed, making it equal to or near synchronous speed ( and other units of the frequency difference in half within, adjusting to Zhou Bo ) and generator voltage, and the other a generator voltage close, in the frequency and voltage are similar, earlier table rotation speed is more and more slow, synchronous indicating lamp is light and dark; when other units and units with the same phase, corresponding table pointer to founder on middle position, light the darkest period, when the unit and the other units and the phase difference of the same table, underneath the central position, this time, period lamp the brightest, when the same table pointer rotates clockwise direction, indicating that the standby generator frequency than the other units should be to reduce the high frequency, and turbine speed, and when the same table pointer according to the anticlockwise direction of rotation, and should be added to generator speed. When the same table pointer slowly clockwise rotation, the pointer near synchronous point, immediately will stay and unit circuit breaker closing, make two generating set parallel. After resection of switches and associated synchronous switch table.

Three, the generator quasi-synchronization, should pay attention to what?

Quasi synchronization is manually operated, the operation is successful and the experience has the very big relations, in order to prevent synchronization, the following three conditions to closing.

1 when the earlier table pointer appears beating phenomenon, not closing, because the same time table may have an interior cassette phenomenon, does not reflect the correct coordinate conditions.

2 when the same table rotates too quickly, and that to generating unit with another generator group of the frequency difference is too large, the circuit breaker closing time is difficult, often make the circuit breaker in the same point of closing, so that no closing.

3 if the earlier table pointer in the same point and does not move, not closing time. This is because the circuit breaker in the closing process if one generator frequency of sudden change, it is possible that circuit breaker are just in a synchronization point.

Four, how to adjust the unit inverse power phenomenon?

When the two generating units of no-load juxtaposed, in between two units, generating a difference frequency and voltage difference problems. And in the two units of monitoring instrument (current meter, power meter, power factor table ), reflect practical inverse power, a speed ( frequency ) caused by the disagreement of the inverse power, the other is a voltage range caused by the inverse function, the adjustment is as follows:

The 1frequency to cause inverse power phenomenon adjustment:

If the two units of different frequencies, difference is larger, on the instrument (current meter, power meter ) show, high speed unit current display positive, power indicator for positive power, conversely, current indicating negative, negative power indicator. The adjustment of one unit speed ( frequency ), apparent power meter indication adjustment, the power meter indication adjusting zero. The two units of power indication are zero, so the two machine speed ( frequency ) basically consistent. However, the current table still have the instructions, this is the voltage difference to cause the phenomenon of inverse function.

The 2voltage difference caused by the phenomenon of inverse power adjustment:

When two units of power meter are zero, and the current meter is still current indication ( i.e. a positive indication ), adjustable wherein a generator voltage adjusting knob, adjust, as the current and power factor of the instructions. The current table indicating elimination (i.e. adjust to zero ), ammeter without instructions, then considered the power factor meter indication, the power factor at lag 0.5above can. Can generally be adjusted to about 0.8, as the best state.

Five, the generator protection circuit

1inverse function

Inverse power phenomenon is produced by the generator speed ( frequency ) and voltage caused by the different, namely a generating unit with positive power, and the other one unit with a negative power. That is to say with negative power unit, then became a load ( the frequency is low, speed inconsistencies ). Voltage phase at the same time, high voltage unit, to the low voltage unit, providing a reactive current and reactive power voltage ( the unit of current meter positive indication ), equivalent in the power supply system, and a condenser group. Low voltage unit, then become a big load, receiving a very reactive current, to maintain the two units of voltage balance ( the unit of current meter reverse indicator ). Monitoring of a unit of voltage is high, or the will of another unit voltage, resulting in a unit has an inverse reactive current, the operating current and rated current is about 20%. Inverse relay action, tripping, alarm, but do not stop.

2 overcurrent:

Now the rated reactive power necessarily, the overload capacity is very low, basically in the rated power of about 5%, allows the load time 15~30minutes, most do not exceed 60minutes, over this time, generating units will be fever, the insulation of the wire can be reduced, but also reduces the use of life. So in the setting of overcurrent protection without special requirements, overcurrent protection setting in the rated current of 110%. On load test, the current band to the rated flow of 110%, overcurrent relay. Trip, alarm, don't stop.

The 3voltage:

In the parallel use of generating units at the most feared power system oscillation, in the event of a vibration system voltage increase, easy to cause electrical equipment and power equipment insulation breakdown, make power supply equipment and electric equipment with paralysis. The parallel use of generating units are equipped with over voltage protection, the set values for the rated voltage of105% is the best. Short over voltage relay, tripping, the alarm action. ( six) switching circuit

Points, closing circuit are connected in parallel by mobile phone, automatic control loop.

1manual closing: each unit can be led by machine or stay and closing, use, manual and car or power supply, using a manual switch.

2automatic switching: each unit may choose to stay and unit, or the first unit; the first unit after startup, the closing loop automatic closing, automatic operation and withdrawal period. Over the same period after the stay and automatic closing parallel operation.

3either manual or automatic switching, switching, once the unit inverse power, the low oil pressure, high water temperature, high temperature, high temperature, voltage, full automatic gates line and load from.

( seven) synchronous circuit

1when the first machine after closing the power delivered to the bus, the bus detection synchronous circuit, and wait and the machine synchronous circuit, after receiving signals, automatically close the synchronism check relay. The bus voltage and the machine voltage to synchronization control module, module automatic detection, the unit of voltage and rotating speed. If the speed is different, corresponding module automatically adjust wait and the machine speed, the parallel condition. Synchronization synchronization module sends found after switch-on instructions, and after receiving the instruction execution unit to be closed, i.e. two units in parallel operation.

2set parallel, synchronous loop automatic quit working state, but must be regarded the automatic synchronization switch exit, prevent the call after the solution column, stay and unit also received a parallel signal, synchronizing device will automatically input, make the unit again tied.

( eight) load distribution

The 1single unit operation, load distributor does not work.

2set parallel after each unit load distributor, at the same time into work, adjusting their own speed, making it the two units of average power allocation, its working principle, is based on the unit power output size (i.e. current size), automatic adjustment D unit speed, so that the load balance.

( nine) voltage adjusting circuit:

1set parallel, must have two units of voltage adjustment at the same value.

2no-load juxtaposed, voltage adjustment knob, the inverse power phenomenon is eliminated, so that the power factor at lag 0.8or so can.

3 parallel unit load, can according to the load, manually adjustable voltage adjusting knob, so that the power factor at the optimum position, later can not be adjusted.

( ten) speed adjusting circuit:

The 1parallel before must take two unit speed ( frequency ) adjusted agreement.

The 2 parallel, according to the same table rotating speed, regulating first machine or stay and unit speed, so that the same table rotation direction, clockwise or anticlockwise rotate speed, the slower the better, but the table pointer must turn to the.

Parallel observation after3, two units of current, power balance, such as difference too big, can adjust the speed of the knob, two units of power to align.

( eleven) instrument detecting circuit:

1before operation, must take a variety of related instrument modified to zero, but the power factor meter and frequency meter is not in zero.

2operation, observe the various instruments