斯坦福發(fā)電機(jī)_斯坦福發(fā)電機(jī)維修_斯坦福發(fā)電機(jī)維修保養(yǎng)

1、斯坦福發(fā)電機(jī)維修保養(yǎng)康明斯發(fā)電機(jī)技術(shù)系統(tǒng)有50多年成功地滿足顧客需要的經(jīng)驗(yàn)，是世界交流發(fā)電機(jī)技術(shù)的先導(dǎo)，康明斯發(fā)電機(jī)技術(shù)系統(tǒng)擁有全球銷售和服務(wù)網(wǎng)絡(luò)，并在英國(guó)、美國(guó)、中國(guó)、印度有生產(chǎn)工廠。無(wú)錫工廠完全按照康明斯發(fā)電機(jī)技術(shù)系統(tǒng)的設(shè)計(jì)及工藝標(biāo)準(zhǔn)來制造斯坦福交流發(fā)電機(jī)。產(chǎn)品設(shè)計(jì)、材料、生產(chǎn)、試驗(yàn)均由英方人員直接管理控制。體積小，重量輕，技術(shù)先進(jìn)，性能可靠是斯坦福發(fā)電機(jī)的重要特性。 康明斯發(fā)電機(jī)技術(shù)系統(tǒng)制造的斯坦福發(fā)電機(jī)可與世界上所有柴油機(jī)配套，如康明斯、帕金斯、VOLVO、MTU、道依茨、卡特彼勒和國(guó)產(chǎn)95、130、135、150、190系列等柴油機(jī)。各系列產(chǎn)品成功供應(yīng)發(fā)電機(jī)組成套廠家，廣泛應(yīng)用于鐵路

2、、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(jī)技術(shù)系統(tǒng)所生產(chǎn)的發(fā)電機(jī)系列為:BC16、BC18、UC224、UC274、HC4、HC5、LV6、HC7。功率范圍為:6.5KW2000KW。HC系列的發(fā)電機(jī)為無(wú)刷旋轉(zhuǎn)磁場(chǎng)結(jié)構(gòu)，電壓最高達(dá)660V/50HZ或60HZ，滿足BS5000標(biāo)準(zhǔn)第三部分和其他國(guó)際標(biāo)準(zhǔn)。在HC4,HC5,HC6/LV6,HC7四個(gè)機(jī)座號(hào)中，200KW-2000 KW范圍內(nèi)，可選1500rpm(50HZ)或1800rpm（60HZ）、4極的發(fā)電機(jī)。在HC6/LV6和HC7兩個(gè)機(jī)座號(hào)中，224KW-1300KW范圍內(nèi)，可選1000rpm（50HZ

3、）或1200rpm(60HZ)、6極的發(fā)電機(jī)。機(jī)座號(hào)位HC4和HC5的發(fā)電機(jī)，其勵(lì)磁系統(tǒng)可為使用AS440或SX421AVR的定子供電或?yàn)槭褂肕X341或MX321AVR的永磁發(fā)電機(jī)（PMG）勵(lì)磁，機(jī)座號(hào)位HC6/LV6和HC7的發(fā)電機(jī)使用MX341或MX321AVR的永磁發(fā)電機(jī)（PMG）勵(lì)磁系統(tǒng)。自勵(lì)A(yù)VR控制的發(fā)電機(jī)，主機(jī)定子通過AS440（或SX421）AVR為勵(lì)磁機(jī)磁場(chǎng)提供勵(lì)磁源，AVR是調(diào)節(jié)勵(lì)磁機(jī)磁場(chǎng)勵(lì)磁電流的控制裝置。AVR根據(jù)來自主機(jī)定子繞組的電壓感應(yīng)信號(hào)作出反饋，通過控制低功率的勵(lì)磁機(jī)磁場(chǎng)調(diào)節(jié)勵(lì)磁機(jī)電樞的整流輸出功率，從而達(dá)到控制主機(jī)磁場(chǎng)電流的要求。AS440AVR通過感應(yīng)兩相

4、平均電壓，確保較高的電壓調(diào)整率，除此之外，它還監(jiān)測(cè)發(fā)動(dòng)機(jī)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(dòng)機(jī)低速時(shí)的國(guó)力，緩減加載時(shí)的沖擊，以減輕發(fā)動(dòng)機(jī)的負(fù)擔(dān)。SX421除了AS440的特點(diǎn)外，還具有三相均方根感應(yīng)的特點(diǎn)，在與外部斷路器（裝在開關(guān)板上）一起使用時(shí)，它還提供過電壓保護(hù)。永磁發(fā)電機(jī)（PMG）勵(lì)磁發(fā)電機(jī)通過MX341(或321)AVR為勵(lì)磁機(jī)提供勵(lì)磁源，AVR是調(diào)節(jié)勵(lì)磁機(jī)勵(lì)磁電流的控制裝置。如果是MX321AVR，則通過一個(gè)隔離變壓器向來自主機(jī)定子繞組的電壓感應(yīng)信號(hào)作出反饋，通過控制低功率的勵(lì)磁機(jī)磁場(chǎng)，調(diào)節(jié)勵(lì)磁機(jī)電樞的整流輸出功率，從而達(dá)到控制主機(jī)磁場(chǎng)電流的要求。PM

5、G系統(tǒng)提供一個(gè)與定子負(fù)載無(wú)關(guān)的恒定的勵(lì)磁電源，提供較高的電動(dòng)機(jī)啟動(dòng)承受能力，并不受非線性負(fù)載（例如可控硅直流電動(dòng)機(jī)）產(chǎn)生的主機(jī)定子輸出電壓的波形畸變的干擾。MX341AVR通過檢測(cè)二相平均電壓來確保較高電壓的調(diào)整率，另外它還檢測(cè)發(fā)動(dòng)機(jī)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(dòng)機(jī)低速時(shí)的過勵(lì)，緩減加載時(shí)的沖擊，以減輕發(fā)動(dòng)機(jī)的負(fù)擔(dān)。它還提供延時(shí)的過勵(lì)保護(hù)，在勵(lì)磁機(jī)磁場(chǎng)電壓過高的情況下對(duì)發(fā)電機(jī)滅磁。MX321除提供MX341巨友的保護(hù)發(fā)動(dòng)機(jī)的減荷特性外，還具有三相均方根檢測(cè)和過電壓保護(hù)的特點(diǎn)。STAMFORD 發(fā)電機(jī)是按照國(guó)際最高質(zhì)量標(biāo)準(zhǔn),配備精心選擇的零部件,采用先進(jìn)的世界級(jí)工藝制

6、造而成。其能適應(yīng)惡劣環(huán)境的全H級(jí)絕緣和最佳效率設(shè)計(jì)的繞組尤其適合于特殊場(chǎng)合的應(yīng)用,標(biāo)準(zhǔn)的12個(gè)可重接出線頭確保滿足各種電壓要求。國(guó)際品牌、人性化設(shè)計(jì)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。發(fā)電機(jī)勵(lì)磁系統(tǒng)典型事故分析1. 保護(hù)裝置誤報(bào)“轉(zhuǎn)子回路一點(diǎn)接地”故障處理（1）故障現(xiàn)象：勵(lì)磁調(diào)節(jié)器起勵(lì)，發(fā)電機(jī)機(jī)端電壓逐步建立，經(jīng)過一個(gè)過渡過程后趨于穩(wěn)定值，然而此時(shí)保護(hù)裝置報(bào)“轉(zhuǎn)子回路一點(diǎn)接地”故障，發(fā)電機(jī)運(yùn)行正常。利用轉(zhuǎn)子電壓表通過測(cè)量發(fā)電機(jī)轉(zhuǎn)子正、負(fù)極對(duì)地電壓，兩極對(duì)地電壓均不為零，說明發(fā)電機(jī)轉(zhuǎn)子沒有發(fā)生一點(diǎn)接地故障。按保護(hù)裝置的復(fù)歸按鈕，“轉(zhuǎn)子回路一點(diǎn)接地”故障信號(hào)消失。

7、60;   （2）故障分析：    分析保護(hù)裝置中“轉(zhuǎn)子回路一點(diǎn)接地”動(dòng)作原理知道，保護(hù)裝置根據(jù)轉(zhuǎn)子電壓判斷轉(zhuǎn)子接地故障。當(dāng)勵(lì)磁調(diào)節(jié)裝置剛起勵(lì)時(shí)，發(fā)出初勵(lì)電源投入命令，轉(zhuǎn)子電壓升高，發(fā)電機(jī)電壓上升，經(jīng)過一段時(shí)間延遲后，勵(lì)磁調(diào)節(jié)裝置自動(dòng)退出初勵(lì)電源，由于勵(lì)磁調(diào)節(jié)器機(jī)端電壓初始參考值低于初勵(lì)電源產(chǎn)生的機(jī)端電壓，所以當(dāng)初勵(lì)電源退出后，轉(zhuǎn)子電壓會(huì)突然下降很多，進(jìn)而轉(zhuǎn)子電壓反饋給保護(hù)，則保護(hù)裝置認(rèn)為是轉(zhuǎn)子回路發(fā)生了短路致使轉(zhuǎn)子電壓突然下降了，所以保護(hù)報(bào)信號(hào)。將勵(lì)磁調(diào)節(jié)器逆變滅磁后重新做試驗(yàn)，在勵(lì)磁調(diào)節(jié)器起勵(lì)前，手工增加勵(lì)磁調(diào)節(jié)器電壓參考值，保證大于初勵(lì)電

8、源產(chǎn)生的發(fā)電機(jī)端電壓，重新起勵(lì)升壓后，發(fā)電機(jī)運(yùn)行正常，保護(hù)裝置沒有發(fā)“轉(zhuǎn)子回路一點(diǎn)接地”故障報(bào)警。    （3）故障處理：    本次事故說明保護(hù)裝置的“轉(zhuǎn)子回路一點(diǎn)接地”功能不夠完善，其動(dòng)作機(jī)理不夠科學(xué)，容易誤動(dòng)，建議完善“轉(zhuǎn)子回路一點(diǎn)接地”功能，或者更換為更為可靠的“轉(zhuǎn)子回路一點(diǎn)接地”保護(hù)裝置。    在“轉(zhuǎn)子回路一點(diǎn)接地”保護(hù)功能未完善前，調(diào)整勵(lì)磁調(diào)節(jié)裝置起勵(lì)初始參考值，要求電壓初始參考值大于初勵(lì)電源產(chǎn)生的發(fā)電機(jī)端電壓。 2. 正常調(diào)節(jié)有功功率引起機(jī)組解列的事故處理（1） 事故現(xiàn)象：某電廠

9、發(fā)電機(jī)組正常運(yùn)行中，根據(jù)中調(diào)要求進(jìn)行升負(fù)荷操作，在增加有功功率過程中，發(fā)電機(jī)輸出無(wú)功功率由50MVar突然降低至-80Mvar，勵(lì)磁調(diào)節(jié)裝置發(fā)出低勵(lì)限制信號(hào)，發(fā)變組保護(hù)裝置報(bào)失磁保護(hù)動(dòng)作，發(fā)電機(jī)解列，滅磁開關(guān)跳閘。    （2）事故分析：    事故發(fā)生后，檢查所有的保護(hù)及異常信號(hào)，發(fā)變組保護(hù)裝置除了失磁保護(hù)動(dòng)作外沒有其它任何事故報(bào)警，故障錄波顯示事故障發(fā)生時(shí)，發(fā)電機(jī)機(jī)端電壓下降，無(wú)功功率進(jìn)相至80Mvar，失磁保護(hù)正確動(dòng)作；    勵(lì)磁調(diào)節(jié)裝置除了發(fā)出低勵(lì)限制信號(hào)沒有其它事故報(bào)警信號(hào)，從勵(lì)磁調(diào)節(jié)裝置錄波

10、分析顯示，勵(lì)磁調(diào)節(jié)裝置中電力系統(tǒng)穩(wěn)定器輸出突降至下限幅值（5%額定機(jī)端電壓），發(fā)電機(jī)無(wú)功急劇下降，進(jìn)相運(yùn)行后，勵(lì)磁調(diào)節(jié)裝置低勵(lì)限制啟動(dòng)，但未來得及調(diào)節(jié)，發(fā)電機(jī)進(jìn)相深度已滿足失磁保護(hù)動(dòng)作條件。    根據(jù)當(dāng)時(shí)只有有功功率增加操作，發(fā)電機(jī)勵(lì)磁調(diào)節(jié)器采用PSS-1A型電力系統(tǒng)穩(wěn)定器，因此分析認(rèn)為事故的發(fā)生是因?yàn)镻SS反調(diào)引起的。對(duì)于PSS-1A型電力系統(tǒng)穩(wěn)定器來說，PSS本身無(wú)法判斷發(fā)電機(jī)有功功率的增加是系統(tǒng)低頻振蕩引起的還是由原動(dòng)機(jī)調(diào)節(jié)引起的，當(dāng)原動(dòng)機(jī)增大有功功率輸出，PSS輸出會(huì)降低發(fā)電機(jī)勵(lì)磁電流，進(jìn)而降低發(fā)電機(jī)無(wú)功功率，這就是PSS-1A型的“反調(diào)”現(xiàn)象。PSS-

11、1A根據(jù)有功功率的變化調(diào)節(jié)發(fā)電機(jī)勵(lì)磁電流，當(dāng)發(fā)電機(jī)有功功率向上變化時(shí)，其“反調(diào)”幅度與有功功率變化幅度成正比，由于本次增加發(fā)電機(jī)有功功率幅度較大，速度較快，PSS的“反調(diào)”直接導(dǎo)致勵(lì)磁電流的突然降低造成深度進(jìn)相，導(dǎo)致發(fā)電機(jī)失磁保護(hù)動(dòng)作解列。    （3）事故處理：    PSS-1A的“反調(diào)”現(xiàn)象對(duì)電廠和系統(tǒng)都是不利的，對(duì)于PSS-1A型電力系統(tǒng)穩(wěn)定器可以在調(diào)節(jié)有功功率時(shí)增加閉鎖PSS輸出的功能，但目前電力系統(tǒng)不推薦這種方法；要消除這種“反調(diào)”現(xiàn)象最有效的方法就是采用PSS-2A或PSS-2B模型，目前國(guó)內(nèi)外多家勵(lì)磁調(diào)節(jié)器已具有該類模

12、型電力系統(tǒng)穩(wěn)定器，并在工程中得到大量使用。對(duì)勵(lì)磁調(diào)節(jié)器的低勵(lì)限制功能進(jìn)行完善，事故過程勵(lì)磁調(diào)節(jié)器最先發(fā)出低勵(lì)磁限制信號(hào)，但由于低勵(lì)限制功能作用太慢，沒有限制發(fā)電機(jī)無(wú)功功率降低才導(dǎo)致發(fā)電機(jī)失磁保護(hù)動(dòng)作，目前業(yè)界中低勵(lì)限制調(diào)節(jié)方法有兩種：一種采用在低勵(lì)限制時(shí)增加電壓參考值的方法限制無(wú)功功率下降，這種方法調(diào)節(jié)過程較平穩(wěn)，但調(diào)節(jié)速度較慢；另一種在低勵(lì)限制動(dòng)作時(shí)直接切換為無(wú)功功率閉環(huán)調(diào)節(jié)，根據(jù)無(wú)功功率下降的幅度及速度進(jìn)行調(diào)節(jié)，這種方法調(diào)節(jié)速度快，有助于發(fā)電機(jī)無(wú)功功率快速恢復(fù)至正常運(yùn)行范圍。 3. 無(wú)功調(diào)差參數(shù)設(shè)置不一致切換導(dǎo)致發(fā)電機(jī)誤強(qiáng)勵(lì)事故分析（1） 事故現(xiàn)象：某電廠200MW機(jī)組處于發(fā)電狀

13、態(tài)，有功200MW，無(wú)功+100Mvar。勵(lì)磁調(diào)節(jié)器正常工作中，A通道為主通道，B通道為從通道，處于備用狀態(tài)，勵(lì)磁調(diào)試人員觀察勵(lì)磁電流，進(jìn)行通道切換試驗(yàn)，通道切換命令（A通道至B通道）發(fā)出后，勵(lì)磁電流突然增大，勵(lì)磁變壓器保護(hù)動(dòng)作，作用于發(fā)電機(jī)解列跳閘。    （2） 事故分析：    事故發(fā)生后，檢查B通道和勵(lì)磁變壓器保護(hù)裝置，結(jié)果表明B通道和勵(lì)磁變壓器保護(hù)裝置均工作正常，重新開機(jī)，B通道也能正常帶負(fù)荷運(yùn)行。但發(fā)現(xiàn)當(dāng)發(fā)電機(jī)空載時(shí)，進(jìn)行A通道和B通道切換，發(fā)電機(jī)定子電壓無(wú)擾動(dòng)；當(dāng)發(fā)電機(jī)負(fù)載時(shí)，進(jìn)行A通道和B通道切換，發(fā)電機(jī)定子電壓有明顯

14、的偏移，遂將事故原因分析重點(diǎn)放在A通道和B通道參數(shù)差異上，比較發(fā)現(xiàn)：A通道無(wú)功調(diào)差系數(shù)為0，B通道無(wú)功調(diào)差系數(shù)誤設(shè)置為-15%。    無(wú)功調(diào)差系數(shù)的定義為發(fā)電機(jī)無(wú)功功率為額定容量時(shí)，疊加在電壓測(cè)量值的發(fā)電機(jī)定子電壓的百分?jǐn)?shù)。無(wú)功功率調(diào)差系數(shù)為-15%的含義為當(dāng)發(fā)電機(jī)無(wú)功功率為額定容量時(shí)，發(fā)電機(jī)定子電壓測(cè)量等效降低-15%，即相當(dāng)于增加勵(lì)磁電流直至發(fā)電機(jī)定子電壓增加15%，事故發(fā)生時(shí)，無(wú)功功率（100MVar）近似為額定容量（235MVA）的42.5%，由于A通道無(wú)功功率調(diào)差系數(shù)為0，B通道無(wú)功功率調(diào)差系數(shù)為-15%，當(dāng)勵(lì)磁從A通道運(yùn)行切換至B通道運(yùn)行時(shí)，相當(dāng)于發(fā)

15、電機(jī)電壓要增加6.37%，勵(lì)磁電流急劇增加，超過勵(lì)磁變壓器保護(hù)啟動(dòng)值，延時(shí)后動(dòng)作跳閘，發(fā)電機(jī)解列滅磁。    （3） 事故處理：    重新設(shè)置無(wú)功功率調(diào)差系數(shù)，A通道和B通道定值相同，發(fā)電機(jī)并網(wǎng)后重新做A通道和B通道切換試驗(yàn)，試驗(yàn)順利完成，發(fā)電機(jī)定子電壓、無(wú)功功率和勵(lì)磁電流無(wú)明顯變化。    檢查勵(lì)磁調(diào)節(jié)器勵(lì)磁電流過勵(lì)限制定值和勵(lì)磁變壓器保護(hù)裝置定值配合情況，保證出現(xiàn)誤強(qiáng)勵(lì)時(shí)，勵(lì)磁調(diào)節(jié)器勵(lì)磁電流過勵(lì)限制先動(dòng)作降低勵(lì)磁電流，不能出現(xiàn)勵(lì)磁變壓器保護(hù)先動(dòng)作于發(fā)電機(jī)解列。 4. 近端負(fù)荷設(shè)置負(fù)調(diào)差引起

16、發(fā)電機(jī)無(wú)功波動(dòng)故障分析（1）故障現(xiàn)象：某大型國(guó)企自備電廠60MW機(jī)組，原勵(lì)磁系統(tǒng)為老式模擬式勵(lì)磁調(diào)節(jié)器，利用檢修期間更換為微機(jī)型勵(lì)磁調(diào)節(jié)器，勵(lì)磁調(diào)節(jié)器調(diào)試完成后，發(fā)電機(jī)進(jìn)行并網(wǎng)試驗(yàn)，試驗(yàn)期間發(fā)電機(jī)無(wú)功功率運(yùn)行穩(wěn)定，數(shù)天后，發(fā)電機(jī)重新開機(jī)后，發(fā)電機(jī)機(jī)端電壓和無(wú)功功率出現(xiàn)長(zhǎng)期不平息的波動(dòng)現(xiàn)象。    （2）故障分析：    故障發(fā)生后，電廠和廠家技術(shù)人員對(duì)故障進(jìn)行技術(shù)分析，對(duì)試驗(yàn)期間的錄波數(shù)據(jù)和故障時(shí)的錄波數(shù)據(jù)進(jìn)行對(duì)比分析，結(jié)果顯示前后的不同：試驗(yàn)期間發(fā)電機(jī)的負(fù)荷主要輸出至高壓母線（35KV），再經(jīng)由高壓母線（35KV）供給企業(yè)使用；而故

17、障時(shí)發(fā)電機(jī)的負(fù)荷主要供給低壓母線（6.3KV）使用。重新對(duì)定值進(jìn)行核算，無(wú)功調(diào)差系數(shù)設(shè)置為-4%，由于發(fā)電機(jī)主接線采用單元接線，因此調(diào)試人員根據(jù)勵(lì)磁標(biāo)準(zhǔn)中無(wú)功功率調(diào)差設(shè)定的建議，選擇無(wú)功調(diào)差系數(shù)為-4%，但是忽略低壓母線負(fù)荷的作用，對(duì)于母線負(fù)荷而言，發(fā)電機(jī)定子與負(fù)荷之間阻抗為零，根據(jù)無(wú)功功率調(diào)差系數(shù)的物理意義，對(duì)于機(jī)端負(fù)荷較重的發(fā)電機(jī)組，其無(wú)功功率調(diào)差系數(shù)必須為正。    （3）故障處理：將無(wú)功功率調(diào)差系數(shù)更改為4%后，發(fā)電機(jī)無(wú)功功率波動(dòng)很快平息后，運(yùn)行穩(wěn)定。Stanford generator repair and maintenanceStanford gen

18、erators Profile,Cummins Generator Technologies (China) Co., Ltd. (Wuxi new era alternator Co., Ltd.) Cummins Generator Technologies in China, the only wholly-owned enterprises, the initial investment of $ 17.6 million. Was established in February 1996, was officially opened in November 1997. The cur

19、rent annual production capacity of 65,000 generators.Cummins Generator Technologies has more than 50 years to meet the customer experience, the pilot of the AC generators technology, Cummins Generator Technologies has a global sales and service network, and production in the United Kingdom, the Unit

20、ed States, China, India factory. The Wuxi plant is in full accordance with the design and technology of the Cummins Generator Technologies produces STAMFORD AC generators. Direct control of product design, materials, production, testing by the British officers. Small size, light weight, advanced tec

21、hnology, reliable performance, the important features of STAMFORD generators.Cummins Generator Technologies STAMFORD generators with all the world diesel engine facilities, such as Cummins, Perkins, Volvo, MTU, and Deutz, Caterpillar and domestic 95,130,135,150,190 series such as diesel. Successful

22、range of products supply generator sets manufacturers, widely used in the field of railways, shipping, postal and telecommunications, military, oil, transportation, high-rise buildings and cold storage containers, etc.Generator series produced by Cummins Generator Technologies: BC16, BC18, UC224, UC

23、274, HC4, HC5, LV6, HC7. Power range: 6.5KW-2000KW. HC series generator Brushless rotating magnetic field structure, the voltage is up to 660V/50HZ or 60HZ, meet the third part of the BS5000 standard and other international standards. HC4, HC5, HC6/LV6, HC7 four frame sizes, 200KW-2000 KW range, opt

24、ional 1500rpm (50Hz) or 1800rpm (60HZ), 4-pole generator. 224KW-1300KW within HC6/LV6 and HC7 two, frame size, optional 1000rpm (50Hz) or 1200rpm (60HZ), 6-pole generator. Frame sizes HC4 and HC5 generators, excitation system to use AS440 or SX421AVR of the stator supply or MX341 or MX321AVR permane

25、nt magnet generator (PMG) excitation, machine seat number HC6/LV6 and HC7 generator MX341 or MX321AVR of permanent magnet generator (PMG) excitation system.Self-stimulation generator AVR control, host stator magnetic field of the exciter by AS440 (or SX421) AVR excitation source, the AVR is adjust t

26、he exciter field excitation current control device. AVR voltage sensing signal from the host of the stator windings to provide feedback, to achieve the control requirements of the host field current by controlling the low power exciter magnetic field to adjust the rectifier output power of the excit

27、er armature. AS440AVR by induction two-phase average voltage, to ensure that high voltage regulation, In addition, it is to monitor the engine speed is lower than the pre-selected speed (Hz) setting, the corresponding lower output voltage to prevent low engine speeds national strength, and mitigatio

28、n of the impact load, in order to reduce the burden on the engine. In addition to the characteristics of the AS440, the SX421 also has a three-phase rms sensing characteristics (installed in the switch board) when used in conjunction with an external circuit breaker, it also provides over-voltage pr

29、otection.Permanent magnet generator (PMG) excitation generator MX341 (or 321) the AVR-exciter provides excitation source, the AVR is to adjust the exciter excitation current control device. If MX321AVR through an isolation transformer to the voltage sense signal from the host of the stator windings

30、feedback control low power exciter magnetic field, adjusting the rectifier output power of the exciter armature, so as to achieve the control requirements of the host field current. PMG system provides a constant excitation power has nothing to do with the stator load, higher motor starting affordab

31、ility is not subject to the nonlinear load (such as SCR DC motor) host stator output voltage waveform distortion interference. MX341AVR to ensure that the adjustment rate of the higher voltage by detecting the two-phase average voltage, the other also detects the engine speed is lower than the pre-s

32、elected speed setting, the output voltage is reduced accordingly, to prevent overexcitation low engine speeds, and mitigation plus set out the time of impact, in order to reduce the burden on the engine. It also provides a delay overexcitation protection, de-excitation of the generator exciter field

33、 voltage is too high. In addition to providing the outside of the the MX341 giant protection of the Friends of the engine minus Haute, the MX321, but also has the characteristics of three-phase rms detection and overvoltage protection.STAMFORD generator is equipped with carefully selected components

34、, the use of the advanced world-class manufacturing process made in accordance with the highest international quality standards. Can adapt to the harsh environment of the whole class H insulation winding design and the best efficiency, especially for special occasions, standard 12 reconnection outle

35、t header to ensure that meet various voltage requirements. International brands, user-friendly design and world-class services STAMFORD many lifelong customers, and broad areas of application.Typical accident analysis of the generator excitation systemA protection device false positives "rotor

36、circuit point grounding" Troubleshooting(1) Fault phenomenon:Excitation excitation regulator, the generator terminal voltage gradually establish a stabilized value after a transition process, the rotor circuit of the protection device "one point grounding fault, the generator is operating

37、normally.Rotor voltmeter by measuring the generator rotor positive and negative ground voltage, the bipolar-to-ground voltage is not zero, indicating that the generator rotor is not a little ground fault occurs. Press the reset button of the protection device, the rotor circuit point grounding fault

38、 signal disappears.    (2) failure analysis:    Analysis of protection device "rotor circuit point grounding the action principle to know to determine the rotor ground fault protection device according to the rotor voltage. Issued early Reed Excitation Eq

39、uipment excitation power input command rotor voltage increases, the generator voltage rises, after a time delay, the excitation regulator device automatically exit early shunt power due to the excitation regulator machine terminal voltage initial machine terminal voltage reference value is lower tha

40、n the early shunt power generated, so the original after the exit of the shunt power, the rotor voltage suddenly dropped a lot, and then the rotor voltage feedback protection, the protection device that is the rotor circuit short-circuit resulting in a sudden drop in the rotor voltage , so to protec

41、t the reported signal. Excitation regulator inverter again after the de-excitation experiments, the excitation of the excitation regulator, manually increase the excitation regulator voltage reference value, to ensure that the generator terminal voltage is greater than the early shunt power generate

42、d, and re-excitation boost generator is operating normally, the protection device is not made to the rotor circuit point grounding fault alarm.    (3) failure treatment:    The accident show that the protective devices, point grounding of the rotor circuit fun

43、ction is not perfect the mechanism of its action is not scientific enough, easy to malfunction, it is recommended to improve the function of the rotor circuit point grounding, or replacement for the more reliable the rotor circuit point grounding protection devices.    In the rot

44、or circuit point grounding protection feature is not perfect, the initial reference value adjustment Excitation Equipment excitation voltage initial reference value is greater than the early shunt power generated by the generator terminal voltage. 2 adjust the active power caused the unit runni

45、ng out of the deal with the accident(1) accident phenomenon:The normal operation of a power plant generating units, the requirements l load operation, according to the tone, increase the active power, reactive power of the generator output by 50MVar suddenly reduced to-80Mvar Excitation Equipment is

46、sued to the low excitation limit signal transformer group protection devices reported missing magnetic protection action, generator column solution, the excitation switch tripping.    (2) Accident analysis:    After the accident, checking all the protection an

47、d abnormal signal transformer unit protection devices in addition to loss of excitation protection action any other accident alarm, fault recorder revealed that the failure occurs, the generator terminal voltage drops, reactive power into In to 80Mvar loss of field protection of the right action;

48、60;   Excitation Equipment In addition to the issue of the low excitation limit signal no other incident alarm signal Excitation Equipment recorded wave analysis shows that the excitation regulator device of power system stabilizer output sags to the lower limit of the amplitude (5% o

49、f the rated terminal voltage) generator The sharp decline in reactive phase advance is running low excitation limit the start of the excitation regulator device, but not enough time to adjust the generator into the depth to meet the operating conditions of loss of excitation protection.  &

50、#160; Was the only active power to increase the operation, the generator excitation regulator PSS-1A power system stabilizer, so analysts believe that the accident is caused because the PSS anti tune. PSS-1A power system stabilizer, PSS itself unable to determine the generator active power incr

51、ease is caused by the low frequency oscillation caused by or motivated by the original regulation, when the prime mover to increase the active power output, the PSS output will reduce the power generation excitation current, thereby reducing the generator reactive power, which is the PSS-1A-type ant

52、i-tune "phenomenon. PSS-1A generator excitation current is adjusted according to changes in the active power, when the upward change of generator active power, its "anti-tune the rate is proportional to the active power changes in amplitude due to the increase the amplitude of generator ac

53、tive power, speed, more PSS "Anti-tune" a direct result of the sudden decrease of the excitation current caused by the depth of phase, resulting in the generator loss of field protection action splitting.    (3) deal with the accident:    The PSS-1A

54、anti-tune "the phenomenon of power plants and systems are unfavorable for the PSS-1A-type power system stabilizer increased atresia PSS output function in the regulation of active power, power system do not recommend this approach; To eliminate this phenomenon of "anti-tune" the most

55、effective method is to use the PSS-2A or PSS-2B model, at home and abroad over the excitation regulator class model of power system stabilizer, and get a lot of use in the project.The low excitation limit function of the excitation regulator perfect accident process excitation regulator was first is

56、sued by the signal of low-excitation limit, but due to the low excitation limit the function of slow, there is no limit to the generator reactive power reduction was a result of generator loss of field protection action, the industry in the low excitation limit adjustment method, there are two: one

57、using the method of increasing the voltage reference value in the low excitation limit limit reactive power decreased, this method is the adjustment process is relatively stable, but regulator slower; another switch directly in the low excitation limit action for reactive power closed-loop regulatio

58、n to be adjusted according to the decrease of reactive power and speed, the speed of this method of adjustment, help generator reactive power is quickly restored to normal operating range. (3) reactive the mobility parameter settings do not match the switch to cause the generator mistaken for s

59、trong excitation accident analysis(1) accident phenomenon:Of 200MW unit in the power generation state, the active 200MW to +100 Mvar reactive. The normal work of the excitation regulator, the A, channel-based channel, B channel from the channel is in standby mode excitation debugging personnel to ob

60、serve the excitation current, channel switching test, after the issue of the channel switching command (channel A to B channel), the excitation current the sudden increase of the excitation transformer protection action, acting on the generator running out of the trip.    (2) Acc

61、ident analysis:    After the accident, check the B channel and the excitation transformer protection devices, the results show that the B channel and the excitation transformer protection devices are working properly, reboot, and B channels can normally run with a load. But when the generator load, the A channel and B channel switching, generator stator voltage without disturbance; A channel and B channel switching when the load of the generator, the generator stator