變壓器基本工作原理范文
時間:2023-11-15 17:46:28
導語(yu):如何才(cai)能寫好一(yi)篇(pian)變(bian)壓器基本工作原(yuan)理(li),這就需(xu)要搜集整理(li)更多的(de)資料和文獻,歡迎閱讀由公(gong)務員(yuan)之家整理(li)的(de)十篇(pian)范文,供你借(jie)鑒(jian)。
篇1
關鍵詞:變壓器;結構;工作原理
變(bian)(bian)壓(ya)器是一種常見的(de)(de)電(dian)氣設備,可用于將某一電(dian)壓(ya)值(zhi)的(de)(de)交流電(dian)變(bian)(bian)換為同頻率的(de)(de)另一電(dian)壓(ya)值(zhi)的(de)(de)交流電(dian)。除變(bian)(bian)換電(dian)壓(ya)外,它還可以變(bian)(bian)換電(dian)流和(he)變(bian)(bian)換阻(zu)抗。變(bian)(bian)壓(ya)器在國民經濟的(de)(de)很多領域里有著非常廣泛的(de)(de)應用。
1.變(bian)壓器的結構(gou)和工作(zuo)原理
變壓器的型式多種多樣,但它們的基本結構是相同的(de),都由鐵(tie)心和繞在鐵(tie)心上的(de)繞組所(suo)組成。根據鐵(tie)心和繞組的(de)相對(dui)位置(zhi)不同,變壓器(qi)可以(yi)分(fen)為心式和殼式兩(liang)種。
1.1 心式(shi)變壓器(qi)
心式變(bian)(bian)壓(ya)器(qi)(qi)的(de)結(jie)構和(he)外形,如圖1所示。其特點是鐵(tie)心1在繞組(zu)(低(di)壓(ya)繞組(zu)2和(he)高壓(ya)繞組(zu)3)里面,即繞組(zu)包圍鐵(tie)心。心式變(bian)(bian)壓(ya)器(qi)(qi)的(de)結(jie)構簡(jian)單(dan),用鐵(tie)量少,繞組(zu)的(de)安裝和(he)絕緣(yuan)比(bi)較容易。容量較大的(de)單(dan)相(xiang)變(bian)(bian)壓(ya)器(qi)(qi)和(he)三相(xiang)電(dian)力(li)變(bian)(bian)壓(ya)器(qi)(qi)都(dou)采用這種結(jie)構。
圖1 心式變壓器的結構和外形
1- 鐵心(xin);2-低壓繞組;3-高壓繞組
1.2 殼式
殼(ke)式(shi)變(bian)(bian)壓(ya)(ya)(ya)(ya)器的(de)結構和(he)外形,如圖2所示。其特點(dian)是繞(rao)組(低壓(ya)(ya)(ya)(ya)繞(rao)組2和(he)高壓(ya)(ya)(ya)(ya)繞(rao)組3)在鐵心1里(li)面,即鐵心包圍(wei)繞(rao)組。殼(ke)式(shi)變(bian)(bian)壓(ya)(ya)(ya)(ya)器用銅量(liang)少(shao),散(san)熱比較(jiao)容易,而且可以(yi)不要(yao)專門的(de)變(bian)(bian)壓(ya)(ya)(ya)(ya)器外殼(ke)。容量(liang)較(jiao)小的(de)單相(xiang)變(bian)(bian)壓(ya)(ya)(ya)(ya)器和(he)某(mou)些特殊用途的(de)變(bian)(bian)壓(ya)(ya)(ya)(ya)器采用這種結構。
圖2 殼式變壓(ya)器的結構和外形
1- 鐵心(xin);2-低壓(ya)繞組;3-高壓(ya)繞組
變(bian)(bian)壓(ya)(ya)器(qi)(qi)的鐵心用(yong)于構成(cheng)磁路(lu)。為(wei)了提(ti)高(gao)導磁能力,降低損(sun)耗(hao),變(bian)(bian)壓(ya)(ya)器(qi)(qi)的鐵心通常(chang)是用(yong)表面涂有(you)絕緣漆膜,厚度為(wei)0.22mm、0.27mm、0.35mm及0.5mm的硅(gui)鋼片疊裝而(er)成(cheng)。變(bian)(bian)壓(ya)(ya)器(qi)(qi)的繞(rao)組又稱(cheng)(cheng)線圈,由絕緣導線繞(rao)制而(er)成(cheng),是變(bian)(bian)壓(ya)(ya)器(qi)(qi)導電的部分(fen)。變(bian)(bian)壓(ya)(ya)器(qi)(qi)的繞(rao)組有(you)一次(ci)繞(rao)組和二次(ci)繞(rao)組。與電源相連的稱(cheng)(cheng)為(wei)一次(ci)繞(rao)組,與負載相連的稱(cheng)(cheng)為(wei)二次(ci)繞(rao)組。
變(bian)壓(ya)(ya)器(qi)(qi)除了(le)鐵(tie)心和(he)(he)繞(rao)組兩個(ge)主要部分之外,還(huan)有(you)(you)一些其(qi)他裝置和(he)(he)附件(jian)。例如(ru),在電力變(bian)壓(ya)(ya)器(qi)(qi)中,有(you)(you)用(yong)(yong)于變(bian)壓(ya)(ya)器(qi)(qi)身散(san)熱的郵箱(變(bian)壓(ya)(ya)器(qi)(qi)的鐵(tie)心和(he)(he)繞(rao)組都津在裝有(you)(you)變(bian)壓(ya)(ya)器(qi)(qi)油(you)(you)的油(you)(you)箱中,這種冷(leng)卻方式叫油(you)(you)津式)、油(you)(you)管(散(san)熱用(yong)(yong))、油(you)(you)枕(儲油(you)(you)柜),有(you)(you)用(yong)(yong)于使帶電引線與(yu)油(you)(you)箱之間可靠絕(jue)緣的絕(jue)緣套(tao)管,以及用(yong)(yong)于觀測變(bian)壓(ya)(ya)器(qi)(qi)油(you)(you)面高度(du)的油(you)(you)位表和(he)(he)油(you)(you)面溫度(du)的溫度(du)表等。
2. 變壓器的工作原理
磁(ci)(ci)通的(de)絕大部(bu)分(fen)通過(guo)鐵(tie)心而閉合,稱為主(zhu)磁(ci)(ci)通,用Φ表示。由于主(zhu)磁(ci)(ci)通同(tong)時(shi)與一次(ci)、二次(ci)繞(rao)組(zu)(zu)相鏈,因此當主(zhu)磁(ci)(ci)通交變(bian)(bian)(bian)(bian)(bian)在一次(ci)繞(rao)組(zu)(zu)中(zhong)產生感應(ying)電(dian)動勢(shi)e1時(shi),也會在二次(ci)繞(rao)組(zu)(zu)中(zhong)產生感應(ying)電(dian)動勢(shi)e2,。如果(guo)二次(ci)繞(rao)組(zu)(zu)接有負(fu)(fu)載,便有電(dian)流i2流過(guo)負(fu)(fu)載,并向負(fu)(fu)載輸出電(dian)功(gong)率。在此,負(fu)(fu)載上的(de)電(dian)流和(he)功(gong)率是(shi)通過(guo)變(bian)(bian)(bian)(bian)(bian)壓(ya)器(qi)鐵(tie)心中(zhong)的(de)交變(bian)(bian)(bian)(bian)(bian)磁(ci)(ci)通,利(li)用電(dian)磁(ci)(ci)感應(ying)作用,從一次(ci)繞(rao)組(zu)(zu)傳(chuan)送(song)到二次(ci)繞(rao)組(zu)(zu)的(de),這就(jiu)是(shi)變(bian)(bian)(bian)(bian)(bian)壓(ya)器(qi)的(de)基(ji)本(ben)工作原(yuan)理。下(xia)面分(fen)別討論變(bian)(bian)(bian)(bian)(bian)壓(ya)器(qi)的(de)電(dian)壓(ya)變(bian)(bian)(bian)(bian)(bian)換、電(dian)流變(bian)(bian)(bian)(bian)(bian)換和(he)阻抗變(bian)(bian)(bian)(bian)(bian)換關系。
2.1 電壓變換
根據電(dian)磁感應(ying)定律,設(she)主磁通(tong) 則
(2.1)
(2.2)
它們的有效值:
(2.3)
(2.4)
由于(yu)漏磁通Φδ1和Φδ2是經(jing)過空氣(qi)隙(xi)的,因此Φδ1、Φδ2分(fen)別與電流(liu)i1、i2成正比,其(qi)作用可用電感 和 來表示,故漏磁感應電動勢
(2.5)
(2.6)
當變壓(ya)器空(kong)載時, ,故 ( 為二次繞組(zu)(zu)的空(kong)載電壓(ya))。由于此時一(yi)次繞組(zu)(zu)上的阻抗壓(ya)降很小(約占U1的0.01%~0.25%),可以忽略(lve)不(bu)計,故 。因此空(kong)載時一(yi)次、二次繞組(zu)(zu)電壓(ya)有效值之(zhi)比
(2.7)
式(shi)中,K稱為變(bian)(bian)壓(ya)(ya)器(qi)的(de)(de)變(bian)(bian)比(bi)(bi)。由式(shi)(2.7)說明,空載(zai)時變(bian)(bian)壓(ya)(ya)器(qi)一次(ci)、二次(ci)繞組(zu)電(dian)(dian)壓(ya)(ya)之(zhi)比(bi)(bi)近似等(deng)于它(ta)們的(de)(de)匝數之(zhi)比(bi)(bi)。這就是(shi)變(bian)(bian)壓(ya)(ya)器(qi)的(de)(de)電(dian)(dian)壓(ya)(ya)變(bian)(bian)換關系。變(bian)(bian)比(bi)(bi)K是(shi)變(bian)(bian)壓(ya)(ya)器(qi)的(de)(de)一個重(zhong)要參數,它(ta)可由變(bian)(bian)壓(ya)(ya)器(qi)的(de)(de)銘牌數據就得,數值(zhi)上等(deng)于一次(ci)、二次(ci)繞組(zu)的(de)(de)額定(ding)電(dian)(dian)壓(ya)(ya)之(zhi)比(bi)(bi)。
2.2電流變換
如上(shang)所述,由于變壓器繞(rao)組的阻(zu)抗壓降很小,可以忽略不(bu)計,因此
(2.8)
式(2.8)說明,在(zai)電源電壓U1和頻率(lv)f不變(bian)(bian)時,感應電動勢E1和主(zhu)(zhu)(zhu)磁(ci)通(tong)的最大值 也近似不變(bian)(bian)。 不變(bian)(bian)則(ze)意(yi)味著產生主(zhu)(zhu)(zhu)磁(ci)通(tong)的磁(ci)動勢不變(bian)(bian)。因為(wei)變(bian)(bian)壓器空載(zai)(zai)時產生主(zhu)(zhu)(zhu)磁(ci)通(tong)的磁(ci)動勢為(wei)N1i0(i0為(wei)空載(zai)(zai)電流),負載(zai)(zai)時產生主(zhu)(zhu)(zhu)磁(ci)通(tong)的磁(ci)動勢為(wei)(N1i1+N2i2),故
N1i1+N2i2=N1i0 或(huo) (2.9)
因為(wei)變壓(ya)器的空載電流I0很(hen)小(約為(wei)I1N的1%~3%),因此一般可(ke)以認為(wei)
(2.10)
式(2.10)說明,二次(ci)繞組磁動勢與一(yi)次(ci)繞組磁動勢相位(wei)近似相反(fan),對主(zhu)磁通是起去磁作用(yong)的(de)。由式(2.10)可得(de)變壓器(qi)一(yi)次(ci)、二次(ci)電流有(you)效(xiao)值之比:
(2.11)
即變壓器一次、二次電流(liu)有效值之比近似等于它們(men)的匝數(shu)比的倒數(shu)。這就(jiu)是(shi)變壓器的電流(liu)變換關系。
3 結束語
本文首先(xian)討(tao)論變壓器(qi)(qi)的結構和(he)工作原理,變壓器(qi)(qi)是電力系統中非常(chang)重要(yao)的電氣設備。
參考文獻
篇2
案例一
教學(xue)內容:交變(bian)電(dian)流
教學目標:
1.知道交變電流(liu)(liu)和(he)直流(liu)(liu)的區別。
2.知(zhi)道中(zhong)性面的(de)概念,理解交變(bian)電流的(de)產(chan)生過(guo)程,掌(zhang)握正(zheng)弦式交變(bian)電流的(de)規律。
3.知(zhi)道(dao)描述交(jiao)變電流(liu)的幾種方法,了(le)解交(jiao)流(liu)發電機的基本構造。
4.通過對(dui)矩形線框在(zai)勻(yun)強磁場(chang)中的勻(yun)速轉動(dong)產生的感應電(dian)流的規律(lv)的探究,進一(yi)步感受法拉第電(dian)磁感應定律(lv)。
導學問題:
1.請你設計一個能產生(sheng)感應電(dian)流的(de)實驗裝(zhuang)(zhuang)置,相(xiang)(xiang)互之間進行交流,并(bing)比較相(xiang)(xiang)互之間設計的(de)不(bu)(bu)同裝(zhuang)(zhuang)置產生(sheng)的(de)感應電(dian)流有何不(bu)(bu)同?
2.探討交變電(dian)流產(chan)生過程及其(qi)變化規律。
(1)線圈轉動(dong)一(yi)周,電流方向(xiang)改變(bian)多少次(ci)?
(2)線圈轉到什么(me)位置時磁通量最(zui)大(da)?這時感應電動(dong)勢如何(he)?
(3)線(xian)圈(quan)轉到什么位(wei)置時(shi)磁通量最小?這時(shi)感應電動勢(shi)如何(he)?
(4)試推導感(gan)應電動(dong)勢大小的變化(hua)規律公式。
3.探究什(shen)么(me)樣的(de)實(shi)驗裝(zhuang)置是實(shi)際能夠使用的(de)發電(dian)機(ji)裝(zhuang)置,為什(shen)么(me)?你對課本上(shang)的(de)發電(dian)裝(zhuang)置有(you)沒有(you)什(shen)么(me)要(yao)改進的(de)地方?
案例二
教學內容:描述交變(bian)電(dian)流的物(wu)理量。
教學目標:
1.了解描(miao)述交變電流(liu)的幾個物理量(liang),知道我國(guo)供電線路交變電流(liu)的周期和頻率。
2.理解交流電(dian)有(you)(you)(you)效(xiao)值(zhi)的(de)(de)物理意義(yi),并(bing)會(hui)運用有(you)(you)(you)效(xiao)值(zhi)的(de)(de)定義(yi)來求解簡單(dan)的(de)(de)交變電(dian)流的(de)(de)有(you)(you)(you)效(xiao)值(zhi).記住正弦式交變電(dian)流的(de)(de)有(you)(you)(you)效(xiao)值(zhi)與最大值(zhi)的(de)(de)關系.通過對交變電(dian)流有(you)(you)(you)效(xiao)值(zhi)的(de)(de)理解和掌握體會(hui)物理學(xue)中的(de)(de)重要(yao)思想——等效(xiao)思想。
導學問題:
1.交(jiao)變電流(liu)的大小和(he)方向都隨(sui)時間變化(hua),你準備怎樣(yang)來描述交(jiao)變電流(liu)?
2.研究課本的(de)(de)“思考(kao)與討論”,你能否(fou)根據交流(liu)電(dian)有效值(zhi)的(de)(de)定(ding)義(yi)求得該交變(bian)電(dian)流(liu)的(de)(de)有效值(zhi)?
3.能(neng)否(fou)利用已有的(de)知識推導出(chu)正(zheng)弦式交(jiao)變電(dian)流的(de)有效值與最大值的(de)關系?(提示可利用圖象法(fa),請試試看)
4.對交(jiao)變電(dian)流(liu)(liu)而言(yan),我們常常接(jie)觸到(dao)另外一個物理量——平均(jun)值(zhi),請你推出正弦式交(jiao)變電(dian)流(liu)(liu)的(de)平均(jun)值(zhi)與最(zui)大值(zhi)、有(you)效值(zhi)的(de)關系。
案例三
教學內(nei)容:電感和(he)電容對交變電流的(de)影響。
教學目標:
1.了(le)解電感和電容對交(jiao)變電流的(de)阻礙作用,知(zhi)道感抗和容抗大小(xiao)與交(jiao)變電流的(de)關(guan)系。
2.通過比較感抗(kang)、容抗(kang)與電(dian)阻的區別,進(jin)一步(bu)體會交變電(dian)流的特點。
3.了解電感和電容在(zai)電器設備(bei)中的無處不在(zai),體會物理知識在(zai)實際(ji)中的應用(yong)。
導學問題:
1.為(wei)什么(me)電感接在(zai)直(zhi)流(liu)和交變電流(liu)的(de)(de)電路中有(you)不同(tong)的(de)(de)結果?你能用已有(you)的(de)(de)知(zhi)識作簡要的(de)(de)分(fen)析(xi)嗎?
2.為什么電容(rong)接在直流(liu)和交變電流(liu)的(de)電路中有不同的(de)結果?你(ni)能用(yong)已有的(de)知(zhi)識作簡要的(de)分析嗎?
3.你能(neng)舉出電(dian)感和電(dian)容在生(sheng)產和生(sheng)活中的(de)應用嗎?
案例四
教學內(nei)容:變壓(ya)器。
教學目標:
1.了(le)解(jie)變(bian)壓(ya)器(qi)的(de)基本構造,知道理想變(bian)壓(ya)器(qi)和實(shi)際(ji)變(bian)壓(ya)器(qi)的(de)區別,理解(jie)變(bian)壓(ya)器(qi)的(de)工作原理。
2.探(tan)究理想變(bian)壓(ya)器的電壓(ya)與匝數的關系。
3.知道(dao)不同種(zhong)類變壓器的共性和個性。
4.探究理想變壓器的電(dian)流與匝數的關(guan)系。
5.通過對變(bian)壓器(qi)的(de)工作(zuo)原理(li)的(de)探究,體會(hui)生產和(he)生活中(zhong)為什么使用的(de)是交(jiao)變(bian)電流,從(cong)而(er)進一(yi)步(bu)感受物理(li)與生活的(de)關系。
導學問題:
1.變壓器的原、副線(xian)(xian)圈是(shi)相互獨立的繞在(zai)閉合鐵芯上,為什(shen)么只(zhi)有(you)原線(xian)(xian)圈中接通電源時,接在(zai)副線(xian)(xian)圈中小燈泡還能亮?是(shi)否接任何(he)電源副線(xian)(xian)圈中的燈泡都(dou)能亮?
2.根據(ju)變壓器的結(jie)構和工作原(yuan)理自我(wo)探究理想變壓器的電壓與匝數的關系,探究不同(tong)種類變壓器的共性和個性。
3.根(gen)據變壓器的(de)(de)結構和工作原理(li)自(zi)我探究理(li)想(xiang)變壓器的(de)(de)電流與(yu)匝數的(de)(de)關(guan)系。
4.閱(yue)讀課本“科學(xue)漫步”,請你(ni)談談在生活中(zhong)和(he)生產實踐(jian)中(zhong)在哪些地方(fang)在使用變壓器?
篇3
關鍵詞:主(zhu)變保(bao)護(hu)電流瓦(wa)斯保(bao)護(hu)變壓器
中(zhong)圖分(fen)類號(hao): TM41 文獻標識碼: A 文章編號(hao):
1關于主變保護的定義
主變指的(de)是一個單位或者變電(dian)站的(de)總(zong)降壓(ya)變壓(ya)器,其(qi)容量一般(ban)比較大。其(qi)他的(de)變壓(ya)器作為配(pei)電(dian)來使(shi)用,一般(ban)稱為配(pei)電(dian)變壓(ya)器,容量稍小。
關于(yu)主(zhu)變(bian)的保(bao)護,作(zuo)為主(zhu)變(bian)壓器,一(yi)般來說容量比較大,要(yao)求工作(zuo)的可靠性較高。對于(yu)不同(tong)容量的變(bian)壓器,所要(yao)求裝設(she)的保(bao)護類別(bie)也不盡相同(tong)。
2變壓器的主保護
變壓器的主保(bao)護主要由瓦斯保(bao)護和(he)差動保(bao)護構成。
2.1瓦斯保護
2.1.1瓦(wa)(wa)斯保(bao)(bao)護(hu)定(ding)義 瓦(wa)(wa)斯保(bao)(bao)護(hu):瓦(wa)(wa)斯保(bao)(bao)護(hu)是(shi)變壓(ya)器(qi)油(you)箱內繞組(zu)短(duan)路故障及異常的主要保(bao)(bao)護(hu)。其原(yuan)理(li)是(shi):變壓(ya)器(qi)內部故障時,在故障點產(chan)生有(you)電弧的短(duan)路電流,造(zao)(zao)成(cheng)油(you)箱內局部過(guo)熱(re)并使(shi)變壓(ya)器(qi)油(you)分解,產(chan)生氣體(ti)(ti)(瓦(wa)(wa)斯),進而造(zao)(zao)成(cheng)噴(pen)油(you),沖(chong)擊氣體(ti)(ti)繼電器(qi),瓦(wa)(wa)斯保(bao)(bao)護(hu)動作(zuo)。
2.1.2瓦斯保護工(gong)作(zuo)原理
2.1.2瓦(wa)(wa)(wa)(wa)斯(si)保(bao)護(hu)(hu)類型 瓦(wa)(wa)(wa)(wa)斯(si)保(bao)護(hu)(hu)分輕瓦(wa)(wa)(wa)(wa)斯(si)和重(zhong)瓦(wa)(wa)(wa)(wa)斯(si)兩種,輕瓦(wa)(wa)(wa)(wa)斯(si)保(bao)護(hu)(hu)作(zuo)用于(yu)信號,重(zhong)瓦(wa)(wa)(wa)(wa)斯(si)保(bao)護(hu)(hu)作(zuo)用于(yu)跳閘。重(zhong)瓦(wa)(wa)(wa)(wa)斯(si)保(bao)護(hu)(hu)是(shi)油箱內部(bu)(bu)故(gu)(gu)(gu)(gu)障(zhang)的主保(bao)護(hu)(hu),它能(neng)反映變壓(ya)器(qi)內部(bu)(bu)的各(ge)種故(gu)(gu)(gu)(gu)障(zhang)。當變壓(ya)器(qi)組(zu)發生少(shao)數匝間短路時,雖然故(gu)(gu)(gu)(gu)障(zhang)點的故(gu)(gu)(gu)(gu)障(zhang)電流很大,但在差(cha)動保(bao)護(hu)(hu)中產(chan)生的差(cha)流可能(neng)不大,差(cha)動保(bao)護(hu)(hu)可能(neng)拒動,此時,靠重(zhong)瓦(wa)(wa)(wa)(wa)斯(si)保(bao)護(hu)(hu)切除故(gu)(gu)(gu)(gu)障(zhang)。
2.1.3瓦(wa)斯(si)保護(hu)(hu)的(de)優點是(shi)不(bu)(bu)僅能(neng)反映變(bian)壓器(qi)(qi)(qi)油(you)箱(xiang)內部(bu)的(de)各(ge)種故(gu)障(zhang),而(er)且還能(neng)反映差(cha)動(dong)保護(hu)(hu)所不(bu)(bu)能(neng)反映的(de)不(bu)(bu)嚴重的(de)匝(za)間短路和(he)鐵心故(gu)障(zhang)。此外(wai),當變(bian)壓器(qi)(qi)(qi)內部(bu)進入空氣時也(ye)有(you)所反映。瓦(wa)斯(si)保護(hu)(hu)靈敏(min)度高、結構簡單、動(dong)作迅速, 其(qi)缺點是(shi)不(bu)(bu)能(neng)反映變(bian)壓器(qi)(qi)(qi)外(wai)部(bu)故(gu)障(zhang)(套管和(he)引出線),因(yin)此不(bu)(bu)能(neng)作為變(bian)壓器(qi)(qi)(qi)各(ge)種故(gu)障(zhang)的(de)唯(wei)一保護(hu)(hu)。瓦(wa)斯(si)保護(hu)(hu)抵抗(kang)外(wai)界干擾的(de)性能(neng)較差(cha),例如劇烈的(de)震動(dong)就容易誤(wu)動(dong)作。如果在安裝瓦(wa)斯(si)繼(ji)電(dian)器(qi)(qi)(qi)時未能(neng)很好(hao)地解決防(fang)油(you)問題或瓦(wa)斯(si)繼(ji)電(dian)器(qi)(qi)(qi)不(bu)(bu)能(neng)很好(hao)地防(fang)水,就有(you)可能(neng)漏油(you)腐蝕電(dian)纜絕緣(yuan)或繼(ji)電(dian)器(qi)(qi)(qi)進水而(er)造(zao)成誤(wu)動(dong)作。
2.2.變壓器(qi)縱差保護(hu)
2.2.1變壓(ya)器(qi)縱差構成(cheng)原理
根據基(ji)爾霍夫第一(yi)定律,0=∑•I;式中∑•I表(biao)示變(bian)壓器(qi)各側電(dian)流的向量和,其物理意(yi)義是:變(bian)壓器(qi)正常(chang)運行或外部故障時,若忽(hu)略勵磁電(dian)流損耗(hao)及其他損耗(hao),則(ze)流入變(bian)壓器(qi)的電(dian)流等于流出變(bian)壓器(qi)的電(dian)流。因此,縱(zong)差保護不應動作。
當變(bian)(bian)壓(ya)器(qi)(qi)內部故障(zhang)時,若忽(hu)略負(fu)荷電流(liu)不計,則只有(you)流(liu)進變(bian)(bian)壓(ya)器(qi)(qi)的(de)電流(liu)而沒(mei)有(you)流(liu)出變(bian)(bian)壓(ya)器(qi)(qi)的(de)電流(liu),其縱(zong)(zong)差(cha)保護動作,切除變(bian)(bian)壓(ya)器(qi)(qi)。見變(bian)(bian)壓(ya)器(qi)(qi)縱(zong)(zong)差(cha)保護原理(li)接線(xian)。
2.2.2變(bian)壓器縱差動保護的基本(ben)原理及邏輯圖
A、變壓器縱差動(dong)保護(hu)(hu)的(de)(de)工作原理(li)與(yu)線路(lu)縱差保護(hu)(hu)的(de)(de)原理(li)相(xiang)同,都是比較被保護(hu)(hu)設備各側電流的(de)(de)相(xiang)位和數值的(de)(de)大小。
B、變(bian)(bian)壓(ya)器(qi)(qi)縱差動保護(hu)與線路差動保護(hu)的(de)(de)區別:由于變(bian)(bian)壓(ya)器(qi)(qi)高壓(ya)側(ce)(ce)和(he)低壓(ya)側(ce)(ce)的(de)(de)額(e)定電(dian)流(liu)(liu)不(bu)相(xiang)(xiang)等(deng)再加上(shang)變(bian)(bian)壓(ya)器(qi)(qi)各側(ce)(ce)電(dian)流(liu)(liu)的(de)(de)相(xiang)(xiang)位往往不(bu)相(xiang)(xiang)同。因此,為(wei)了(le)保證縱差動保護(hu)的(de)(de)正確工作,須適當選擇各側(ce)(ce)電(dian)流(liu)(liu)互感(gan)器(qi)(qi)的(de)(de)變(bian)(bian)比,及各側(ce)(ce)電(dian)流(liu)(liu)相(xiang)(xiang)位的(de)(de)補償使(shi)得(de)正常運行和(he)區外短(duan)路故障時,兩(liang)側(ce)(ce)二次(ci)電(dian)流(liu)(liu)相(xiang)(xiang)等(deng)。 例如如下所示的(de)(de)雙(shuang)繞組(zu)變(bian)(bian)壓(ya)器(qi)(qi)
3.主變差動保(bao)護分(fen)析
在主變(bian)差動保(bao)護(hu)所用電(dian)(dian)流(liu)互感(gan)(gan)器選(xuan)擇時,除應(ying)選(xuan)帶(dai)有氣隙(xi)的(de)D級鐵芯互感(gan)(gan)器外(wai),還應(ying)適當(dang)地增大電(dian)(dian)流(liu)互感(gan)(gan)器變(bian)比,以降(jiang)低短(duan)路(lu)(lu)電(dian)(dian)流(liu)倍(bei)數,這樣可(ke)以有效削(xue)弱勵磁涌流(liu),減少差動回路(lu)(lu)中產生的(de)不平衡電(dian)(dian)流(liu),提高差動保(bao)護(hu)的(de)靈敏(min)度。這對避免保(bao)護(hu)區外(wai)故障,尤其(qi)是最嚴重的(de)三相金(jin)屬性短(duan)路(lu)(lu)而導致的(de)主變(bian)差動保(bao)護(hu)誤動作(zuo)尤為有效。下面將通過實例進行分析:
實例:一臺三相三繞組降壓(ya)變(bian)壓(ya)器(qi),容量Se=40.5MVA,電壓(ya)110±2×2.5%kV/35±2×2.5%kV/11kV,接(jie)線方(fang)式:Ydd11-11,變(bian)壓(ya)器(qi)額定(ding)電流:213A/608A/2130A。主變(bian)差(cha)動(dong)保(bao)護采用BCH-2型(xing)差(cha)動(dong)繼電器(qi)。
已確定110kV側為(wei)基(ji)本(ben)側。主(zhu)變差動保護(hu)部分整定值如下(計算過程略):
差動線圈的計(ji)算(suan)匝(za)數:Wcd.js=6.3匝(za),實際匝(za)數向(xiang)下取(qu)整,取(qu)Wcd.js=6匝(za);
繼(ji)電(dian)器的實(shi)際動作(zuo)電(dian)流:Idz=10A;
靈(ling)敏度K1m=2.1。
該變電所曾發生(sheng)10kV線路(lu)(lu)出線處(chu)因外(wai)力破壞導(dao)致三(san)相金屬(shu)性短路(lu)(lu),10kV線路(lu)(lu)電流速(su)斷動(dong)(dong)作,相繼引(yin)起主(zhu)變差動(dong)(dong)保(bao)護(hu)(hu)誤動(dong)(dong)作。我們初步(bu)分析因短路(lu)(lu)點離保(bao)護(hu)(hu)太近(jin),又是(shi)最嚴重的(de)(de)三(san)相金屬(shu)性短路(lu)(lu),短路(lu)(lu)電流極大(da),當(dang)外(wai)部故(gu)障切除,電壓恢復時,出現數值很大(da)的(de)(de)勵磁(ci)涌流,從而使差動(dong)(dong)回路(lu)(lu)產生(sheng)的(de)(de)不(bu)平衡電流大(da)于整定(ding)(ding)電流值而導(dao)致主(zhu)變差動(dong)(dong)保(bao)護(hu)(hu)誤動(dong)(dong)作。但如(ru)果提(ti)高保(bao)護(hu)(hu)定(ding)(ding)值,如(ru)保(bao)護(hu)(hu)定(ding)(ding)值增大(da)為11A,則靈(ling)敏度變小K1m=1.91<2,不(bu)能滿(man)足靈(ling)敏度的(de)(de)要求。
經綜合分析(xi),認(ren)為采用BCH-2型具有速飽(bao)和(he)(he)(he)(he)(he)變(bian)(bian)流(liu)(liu)(liu)差(cha)動(dong)繼電(dian)(dian)(dian)器(qi)(qi)(qi)(qi)(qi)來避免勵(li)磁(ci)涌(yong)流(liu)(liu)(liu)存在一(yi)(yi)定缺陷。從勵(li)磁(ci)涌(yong)流(liu)(liu)(liu)的(de)(de)特性看(kan),對三相變(bian)(bian)壓器(qi)(qi)(qi)(qi)(qi),電(dian)(dian)(dian)壓恢復時,至少(shao)有兩相出現程(cheng)度不(bu)同的(de)(de)勵(li)磁(ci)涌(yong)流(liu)(liu)(liu),即三相勵(li)磁(ci)涌(yong)流(liu)(liu)(liu)中可能(neng)有一(yi)(yi)相沒有非周期(qi)分量(liang),這(zhe)時速飽(bao)和(he)(he)(he)(he)(he)變(bian)(bian)流(liu)(liu)(liu)器(qi)(qi)(qi)(qi)(qi)將(jiang)失去作用。分析(xi)保(bao)護定值,差(cha)動(dong)保(bao)護電(dian)(dian)(dian)流(liu)(liu)(liu)互(hu)感(gan)器(qi)(qi)(qi)(qi)(qi)變(bian)(bian)比(bi)選得有些偏低(di),且趨于(yu)飽(bao)和(he)(he)(he)(he)(he)。這(zhe)樣(yang)當發生(sheng)最嚴(yan)重的(de)(de)三相金屬性短(duan)路(lu)時,電(dian)(dian)(dian)流(liu)(liu)(liu)互(hu)感(gan)器(qi)(qi)(qi)(qi)(qi)因飽(bao)和(he)(he)(he)(he)(he)其誤(wu)差(cha)增(zeng)大,不(bu)但(dan)增(zeng)大不(bu)平(ping)衡(heng)電(dian)(dian)(dian)流(liu)(liu)(liu),而且使電(dian)(dian)(dian)流(liu)(liu)(liu)互(hu)感(gan)器(qi)(qi)(qi)(qi)(qi)嚴(yan)重過載。而增(zeng)大電(dian)(dian)(dian)流(liu)(liu)(liu)互(hu)感(gan)器(qi)(qi)(qi)(qi)(qi)變(bian)(bian)比(bi),可降(jiang)低(di)短(duan)路(lu)電(dian)(dian)(dian)流(liu)(liu)(liu)倍(bei)數,減(jian)少(shao)差(cha)動(dong)回路(lu)中的(de)(de)不(bu)平(ping)衡(heng)電(dian)(dian)(dian)流(liu)(liu)(liu),因而能(neng)有效地(di)削(xue)弱勵(li)磁(ci)涌(yong)流(liu)(liu)(liu)和(he)(he)(he)(he)(he)區(qu)外故障產生(sheng)的(de)(de)不(bu)平(ping)衡(heng)電(dian)(dian)(dian)流(liu)(liu)(liu)。
篇4
【關鍵詞】差動變(bian)壓器(qi)式傳感器(qi);原理;應(ying)用(yong)
0 前言
差動變(bian)(bian)壓器(qi)(qi)式傳(chuan)感(gan)(gan)器(qi)(qi)是在傳(chuan)統(tong)傳(chuan)感(gan)(gan)器(qi)(qi)上改進,利用物(wu)(wu)(wu)體(ti)在移(yi)動時產(chan)生的(de)能(neng)量(liang)推動電壓產(chan)生的(de)變(bian)(bian)化而求(qiu)出所求(qiu)量(liang)的(de)物(wu)(wu)(wu)理(li)實驗器(qi)(qi)材,即(ji)將(jiang)各(ge)(ge)個(ge)物(wu)(wu)(wu)理(li)量(liang)變(bian)(bian)換為電量(liang)的(de)變(bian)(bian)化。它廣泛的(de)應用于各(ge)(ge)種(zhong)物(wu)(wu)(wu)理(li)量(liang)的(de)測量(liang),如伸長、壓力、應變(bian)(bian)、振(zhen)動、物(wu)(wu)(wu)體(ti)的(de)厚度(du)等(deng)。傳(chuan)統(tong)的(de)傳(chuan)感(gan)(gan)器(qi)(qi)只能(neng)對(dui)一些(xie)物(wu)(wu)(wu)理(li)量(liang)進行簡單且比(bi)較繁(fan)瑣(suo)的(de)測量(liang),這顯然(ran)難(nan)以(yi)滿足(zu)復雜系統(tong)的(de)要(yao)求(qiu),所以(yi)差動變(bian)(bian)壓器(qi)(qi)式傳(chuan)感(gan)(gan)器(qi)(qi)出現(xian)了,它的(de)問世預示(shi)著(zhu)新時展的(de)潮(chao)流,在信息化時代(dai),要(yao)想跟(gen)上時展潮(chao)流,就要(yao)熟練的(de)掌握(wo)基礎技術。
1 差(cha)動變壓器(qi)式傳感器(qi)的基(ji)本情(qing)況(kuang)
1.1 基本構造
差(cha)動變(bian)壓器是一(yi)種廣泛用于(yu)電(dian)子技(ji)術和非(fei)電(dian)量檢測中的(de)(de)變(bian)壓器裝置,主(zhu)要是差(cha)動變(bian)壓器式壓力(li)傳(chuan)感器、差(cha)動變(bian)壓器式位(wei)移傳(chuan)感器、差(cha)動變(bian)壓器式電(dian)容傳(chuan)感器這幾種,不同(tong)種類的(de)(de)變(bian)壓器有(you)不同(tong)的(de)(de)構造,但基本的(de)(de)構造是一(yi)致的(de)(de)。線(xian)(xian)(xian)(xian)(xian)框和?鐵(tie)(tie)芯構成系統(tong)的(de)(de)主(zhu)要部分。在線(xian)(xian)(xian)(xian)(xian)框上繞有(you)一(yi)組(zu)線(xian)(xian)(xian)(xian)(xian)圈(quan)(quan),該線(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)相當于(yu)輸入線(xian)(xian)(xian)(xian)(xian)圈(quan)(quan),將鐵(tie)(tie)芯放置在線(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)中央圓柱孔中,兩個(ge)(ge)或(huo)多個(ge)(ge)帶有(you)鐵(tie)(tie)芯的(de)(de)線(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)又構成線(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)組(zu),線(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)組(zu)分為初級(ji)線(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)和次級(ji)線(xian)(xian)(xian)(xian)(xian)圈(quan)(quan),初次級(ji)線(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)間有(you)街鐵(tie)(tie),在互感的(de)(de)作(zuo)用下,銜鐵(tie)(tie)能(neng)隨兩個(ge)(ge)線(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)的(de)(de)移動而移動,此(ci)外(wai),還有(you)一(yi)些部件如鐵(tie)(tie)架、激磁線(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)、補償線(xian)(xian)(xian)(xian)(xian)圈(quan)(quan)、屏蔽套等。
1.2 運作原理
差(cha)動(dong)變壓(ya)器(qi)式(shi)傳感(gan)器(qi)的(de)(de)(de)(de)工作原(yuan)理是(shi)由變換交(jiao)流(liu)(liu)電(dian)(dian)壓(ya)、電(dian)(dian)流(liu)(liu)和阻抗這三個器(qi)件組(zu)成的(de)(de)(de)(de)變壓(ya)器(qi),當(dang)交(jiao)流(liu)(liu)電(dian)(dian)流(liu)(liu)通過初級(ji)(ji)線(xian)圈時(shi),就(jiu)會(hui)有交(jiao)流(liu)(liu)磁通在鐵芯中(zhong)產(chan)生,從而感(gan)應(ying)出(chu)電(dian)(dian)壓(ya)和電(dian)(dian)流(liu)(liu)。若是(shi)在初級(ji)(ji)線(xian)圈中(zhong)加有適當(dang)頻率(lv)的(de)(de)(de)(de)電(dian)(dian)壓(ya)刺激(ji)時(shi),在兩個次級(ji)(ji)線(xian)圈中(zhong)就(jiu)會(hui)產(chan)生感(gan)應(ying)電(dian)(dian)勢。當(dang)使鐵芯向右或向左(zuo)移(yi)動(dong)時(shi),在兩個次級(ji)(ji)線(xian)圈內所感(gan)應(ying)的(de)(de)(de)(de)電(dian)(dian)勢則會(hui)一(yi)個增加和一(yi)個減少。如(ru)果接成反向串聯(lian)輸出(chu),則傳感(gan)器(qi)的(de)(de)(de)(de)輸出(chu)電(dian)(dian)壓(ya)等于(yu)兩個次級(ji)(ji)線(xian)圈的(de)(de)(de)(de)電(dian)(dian)勢差(cha),因為兩個次級(ji)(ji)線(xian)圈做得一(yi)樣,因此(ci),當(dang)鐵芯放在中(zhong)央(yang)的(de)(de)(de)(de)位置(zhi)時(shi),傳感(gan)器(qi)的(de)(de)(de)(de)電(dian)(dian)壓(ya)會(hui)為零。以上就(jiu)是(shi)差(cha)動(dong)變壓(ya)器(qi)傳感(gan)器(qi)的(de)(de)(de)(de)工作原(yuan)理。
1.3 工作性能
差(cha)(cha)(cha)動(dong)(dong)變壓器(qi)(qi)式傳(chuan)(chuan)(chuan)(chuan)感(gan)器(qi)(qi)的(de)主(zhu)要的(de)性(xing)能(neng)(neng)是靈(ling)(ling)(ling)(ling)敏(min)(min)(min)度(du)(du)(du)(du)(du)和(he)(he)線(xian)(xian)性(xing)度(du)(du)(du)(du)(du)。差(cha)(cha)(cha)動(dong)(dong)變壓器(qi)(qi)傳(chuan)(chuan)(chuan)(chuan)感(gan)器(qi)(qi)的(de)靈(ling)(ling)(ling)(ling)敏(min)(min)(min)度(du)(du)(du)(du)(du)是指街鐵移動(dong)(dong)時(shi)產生的(de)輸出電勢的(de)變化,單位用mV/mm來(lai)表示,而線(xian)(xian)性(xing)度(du)(du)(du)(du)(du)則是指因變量(liang)和(he)(he)自變量(liang)之(zhi)間(jian)的(de)線(xian)(xian)性(xing)關(guan)系,線(xian)(xian)性(xing)度(du)(du)(du)(du)(du)具(ju)有(you)一定(ding)的(de)范圍,差(cha)(cha)(cha)動(dong)(dong)變壓器(qi)(qi)式傳(chuan)(chuan)(chuan)(chuan)感(gan)器(qi)(qi)的(de)靈(ling)(ling)(ling)(ling)敏(min)(min)(min)度(du)(du)(du)(du)(du)和(he)(he)線(xian)(xian)性(xing)度(du)(du)(du)(du)(du)越高(gao),它(ta)的(de)工作(zuo)性(xing)能(neng)(neng)也(ye)越高(gao)。差(cha)(cha)(cha)動(dong)(dong)變壓器(qi)(qi)式傳(chuan)(chuan)(chuan)(chuan)感(gan)器(qi)(qi)的(de)靈(ling)(ling)(ling)(ling)敏(min)(min)(min)度(du)(du)(du)(du)(du)的(de)高(gao)低與初級電壓、次級繞組匝數(shu)(shu)和(he)(he)激勵(li)電壓有(you)關(guan)。首先靈(ling)(ling)(ling)(ling)敏(min)(min)(min)度(du)(du)(du)(du)(du)與次級匝數(shu)(shu)是線(xian)(xian)性(xing)關(guan)系,次級匝數(shu)(shu)增(zeng)(zeng)加,靈(ling)(ling)(ling)(ling)敏(min)(min)(min)度(du)(du)(du)(du)(du)也(ye)跟著增(zeng)(zeng)加,但次級匝數(shu)(shu)不能(neng)(neng)無限制增(zeng)(zeng)加。靈(ling)(ling)(ling)(ling)敏(min)(min)(min)度(du)(du)(du)(du)(du)和(he)(he)初級電壓成正(zheng)比關(guan)系,在頻(pin)率(lv)很低時(shi),靈(ling)(ling)(ling)(ling)敏(min)(min)(min)度(du)(du)(du)(du)(du)隨(sui)頻(pin)率(lv)的(de)增(zeng)(zeng)加而增(zeng)(zeng)加,但當頻(pin)率(lv)升高(gao),線(xian)(xian)圈的(de)感(gan)抗大(da)大(da)高(gao)于(yu)其電阻時(shi),靈(ling)(ling)(ling)(ling)敏(min)(min)(min)度(du)(du)(du)(du)(du)則與頻(pin)率(lv)無關(guan)。線(xian)(xian)性(xing)度(du)(du)(du)(du)(du)則是和(he)(he)靈(ling)(ling)(ling)(ling)敏(min)(min)(min)度(du)(du)(du)(du)(du)有(you)關(guan),靈(ling)(ling)(ling)(ling)敏(min)(min)(min)度(du)(du)(du)(du)(du)越高(gao)線(xian)(xian)性(xing)度(du)(du)(du)(du)(du)就(jiu)越高(gao)。總之(zhi),認識差(cha)(cha)(cha)動(dong)(dong)變壓器(qi)(qi)傳(chuan)(chuan)(chuan)(chuan)感(gan)器(qi)(qi)的(de)性(xing)能(neng)(neng),對于(yu)它(ta)的(de)工作(zuo)性(xing)能(neng)(neng)有(you)個熟練的(de)掌(zhang)握,保證差(cha)(cha)(cha)動(dong)(dong)變壓器(qi)(qi)傳(chuan)(chuan)(chuan)(chuan)感(gan)器(qi)(qi)的(de)正(zheng)確使(shi)用和(he)(he)工作(zuo)研(yan)究的(de)展(zhan)開。
2 差(cha)動變壓器式傳感器運(yun)用
2.1 運用方面
差(cha)動(dong)(dong)變(bian)壓(ya)器(qi)(qi)傳(chuan)(chuan)(chuan)感(gan)(gan)(gan)(gan)(gan)器(qi)(qi)在(zai)現實(shi)生(sheng)(sheng)活(huo)中有(you)(you)(you)著(zhu)非(fei)常廣(guang)泛應(ying)(ying)用(yong)。它的(de)(de)(de)種類(lei)有(you)(you)(you)很多,包括壓(ya)力(li)傳(chuan)(chuan)(chuan)感(gan)(gan)(gan)(gan)(gan)器(qi)(qi)、位(wei)(wei)移(yi)(yi)傳(chuan)(chuan)(chuan)感(gan)(gan)(gan)(gan)(gan)器(qi)(qi)、加(jia)速(su)(su)度(du)傳(chuan)(chuan)(chuan)感(gan)(gan)(gan)(gan)(gan)器(qi)(qi)等,這些差(cha)動(dong)(dong)變(bian)壓(ya)器(qi)(qi)在(zai)許多領域(yu)都有(you)(you)(you)著(zhu)非(fei)常廣(guang)泛的(de)(de)(de)應(ying)(ying)用(yong)。對于(yu)壓(ya)力(li)傳(chuan)(chuan)(chuan)感(gan)(gan)(gan)(gan)(gan)器(qi)(qi),主要通過(guo)彈性敏(min)感(gan)(gan)(gan)(gan)(gan)器(qi)(qi)將非(fei)電(dian)(dian)量(liang)壓(ya)力(li)參(can)數(shu)(shu)變(bian)為位(wei)(wei)移(yi)(yi)量(liang)送至測(ce)量(liang)電(dian)(dian)路,再通過(guo)對電(dian)(dian)路各(ge)個量(liang)的(de)(de)(de)數(shu)(shu)學(xue)計(ji)算計(ji)算出壓(ya)力(li)。位(wei)(wei)移(yi)(yi)測(ce)傳(chuan)(chuan)(chuan)感(gan)(gan)(gan)(gan)(gan)器(qi)(qi)是在(zai)電(dian)(dian)磁(ci)感(gan)(gan)(gan)(gan)(gan)應(ying)(ying)原(yuan)理下測(ce)量(liang)出位(wei)(wei)移(yi)(yi),當初級(ji)(ji)線(xian)圈(quan)被供給一(yi)定(ding)(ding)頻率的(de)(de)(de)交變(bian)電(dian)(dian)壓(ya)時,次(ci)級(ji)(ji)線(xian)圈(quan)就產生(sheng)(sheng)了感(gan)(gan)(gan)(gan)(gan)應(ying)(ying)電(dian)(dian)動(dong)(dong)勢,隨著(zhu)鐵芯(xin)的(de)(de)(de)位(wei)(wei)置不(bu)同(tong), 次(ci)級(ji)(ji)線(xian)圈(quan)產生(sheng)(sheng)的(de)(de)(de)感(gan)(gan)(gan)(gan)(gan)應(ying)(ying)電(dian)(dian)動(dong)(dong)勢也(ye)不(bu)同(tong),由(you)電(dian)(dian)動(dong)(dong)勢的(de)(de)(de)不(bu)同(tong)推出的(de)(de)(de)位(wei)(wei)移(yi)(yi)量(liang)的(de)(de)(de)大小。對于(yu)加(jia)速(su)(su)度(du)傳(chuan)(chuan)(chuan)感(gan)(gan)(gan)(gan)(gan)器(qi)(qi),主要依據的(de)(de)(de)原(yuan)理是牛頓第(di)二定(ding)(ding)律即質量(liang)塊的(de)(de)(de)位(wei)(wei)移(yi)(yi)與(yu)被測(ce)物體的(de)(de)(de)加(jia)速(su)(su)度(du)正(zheng)比,將加(jia)速(su)(su)度(du)的(de)(de)(de)測(ce)量(liang)轉變(bian)為位(wei)(wei)移(yi)(yi)的(de)(de)(de)測(ce)量(liang)。事實(shi)上,差(cha)動(dong)(dong)變(bian)壓(ya)器(qi)(qi)傳(chuan)(chuan)(chuan)感(gan)(gan)(gan)(gan)(gan)器(qi)(qi)的(de)(de)(de)種類(lei)還有(you)(you)(you)很多,應(ying)(ying)用(yong)范(fan)圍也(ye)都非(fei)常的(de)(de)(de)廣(guang)泛,需要相關(guan)的(de)(de)(de)研發人員進(jin)一(yi)步學(xue)習(xi)與(yu)探索,以(yi)促(cu)進(jin)差(cha)動(dong)(dong)變(bian)壓(ya)器(qi)(qi)的(de)(de)(de)進(jin)一(yi)步應(ying)(ying)用(yong)和(he)改進(jin)。
2.2 使(shi)用的范圍
差動(dong)變(bian)(bian)壓(ya)器(qi)(qi)傳感器(qi)(qi)是非(fei)常(chang)重要(yao)的高科技產(chan)品,可廣泛應(ying)用(yong)于航天航空、機械、建(jian)(jian)筑、紡織、鐵路、煤炭、冶金(jin)、塑(su)料、化工(gong)(gong)以及科研院(yuan)校等國民(min)經濟各行各業(ye)(ye),結構簡(jian)單(dan)使用(yong)范(fan)圍(wei)(wei)廣計算方(fang)法簡(jian)單(dan)的優(you)點讓它能在各個方(fang)面都(dou)有(you)著非(fei)常(chang)重要(yao)的應(ying)用(yong),接下來(lai)我們將簡(jian)單(dan)的談(tan)談(tan)變(bian)(bian)壓(ya)器(qi)(qi)的使用(yong)范(fan)圍(wei)(wei)。在民(min)生鄰域中(zhong),運用(yong)在建(jian)(jian)筑中(zhong)的高度精(jing)確測(ce)量(liang)、地基的精(jing)煉挖掘上,鋼鐵工(gong)(gong)業(ye)(ye)鄰域,高爐(lu)的爐(lu)頂水(shui)平(ping)檢(jian)(jian)測(ce)、連續(xu)鑄(zhu)造間隙、砂(sha)型(xing)振動(dong)、凸(tu)度等的誤差檢(jian)(jian)測(ce),鐵水(shui)包(bao)、中(zhong)間包(bao)的滑(hua)動(dong)水(shui)口的位(wei)(wei)置檢(jian)(jian)測(ce)。重型(xing)電機工(gong)(gong)業(ye)(ye)鄰域上,蒸汽透平(ping)的主閥(fa)(fa)檢(jian)(jian)查,旁(pang)通閥(fa)(fa)的閥(fa)(fa)升(sheng)程(cheng)檢(jian)(jian)測(ce),升(sheng)降機的姿(zi)勢(shi)監控,在航天航空鄰域的軸(zhou)徑跳(tiao)動(dong)檢(jian)(jian)測(ce)、閥(fa)(fa)位(wei)(wei)檢(jian)(jian)測(ce)與控制、輥縫(feng)間隙控制等。還有(you)復雜的金(jin)屬(shu)加(jia)工(gong)(gong)、機床及工(gong)(gong)具定位(wei)(wei)、液(ye)壓(ya)缸定位(wei)(wei)、自卸載(zai)重車等都(dou)有(you)不同程(cheng)度的用(yong)到變(bian)(bian)壓(ya)器(qi)(qi)。總(zong)之(zhi),變(bian)(bian)壓(ya)器(qi)(qi)的應(ying)用(yong)范(fan)圍(wei)(wei)有(you)很(hen)多,方(fang)面也很(hen)廣泛,需要(yao)使用(yong)者不斷的發現與學習,以不斷地擴大變(bian)(bian)壓(ya)器(qi)(qi)的使用(yong)范(fan)圍(wei)(wei)。
2.3 如何使用差(cha)動變壓器(qi)
清楚差(cha)(cha)動(dong)變壓(ya)(ya)器(qi)(qi)(qi)(qi)的(de)(de)(de)(de)(de)基本結構是(shi)(shi)(shi)(shi)正確(que)使(shi)(shi)(shi)用(yong)(yong)它的(de)(de)(de)(de)(de)前提。詳細(xi)閱讀(du)差(cha)(cha)動(dong)變壓(ya)(ya)器(qi)(qi)(qi)(qi)傳(chuan)感(gan)器(qi)(qi)(qi)(qi)的(de)(de)(de)(de)(de)使(shi)(shi)(shi)用(yong)(yong)手冊,熟悉差(cha)(cha)動(dong)變壓(ya)(ya)器(qi)(qi)(qi)(qi)傳(chuan)感(gan)器(qi)(qi)(qi)(qi)的(de)(de)(de)(de)(de)使(shi)(shi)(shi)用(yong)(yong)準(zhun)則和(he)注意事項,在使(shi)(shi)(shi)用(yong)(yong)前要(yao)學會并熟練(lian)掌握差(cha)(cha)動(dong)變壓(ya)(ya)器(qi)(qi)(qi)(qi)傳(chuan)感(gan)器(qi)(qi)(qi)(qi)的(de)(de)(de)(de)(de)工作原理(li)和(he)足夠的(de)(de)(de)(de)(de)知識儲備(bei)(bei),主要(yao)的(de)(de)(de)(de)(de)知識有(you)牛頓定(ding)(ding)(ding)律、電(dian)(dian)(dian)磁感(gan)應(ying)、壓(ya)(ya)力計(ji)算、動(dong)量(liang)定(ding)(ding)(ding)理(li)等。將(jiang)這些準(zhun)備(bei)(bei)做(zuo)好(hao)后(hou),便是(shi)(shi)(shi)(shi)使(shi)(shi)(shi)用(yong)(yong)差(cha)(cha)動(dong)變壓(ya)(ya)器(qi)(qi)(qi)(qi),在使(shi)(shi)(shi)用(yong)(yong)時要(yao)將(jiang)可能(neng)出現的(de)(de)(de)(de)(de)問(wen)題(ti)事先(xian)做(zuo)好(hao)應(ying)對的(de)(de)(de)(de)(de)措施,避免出現問(wen)題(ti)時一無所知。使(shi)(shi)(shi)用(yong)(yong)結束后(hou),檢(jian)(jian)查(cha)傳(chuan)感(gan)器(qi)(qi)(qi)(qi)的(de)(de)(de)(de)(de)各個部(bu)分(fen),無誤(wu)后(hou)將(jiang)傳(chuan)感(gan)器(qi)(qi)(qi)(qi)關(guan)好(hao),關(guan)閉后(hou)將(jiang)變壓(ya)(ya)器(qi)(qi)(qi)(qi)放(fang)到規(gui)(gui)定(ding)(ding)(ding)地方。此(ci)外,還(huan)要(yao)對傳(chuan)感(gan)器(qi)(qi)(qi)(qi)進(jin)(jin)行(xing)定(ding)(ding)(ding)期的(de)(de)(de)(de)(de)檢(jian)(jian)查(cha)和(he)維(wei)(wei)(wei)修(xiu)(xiu),定(ding)(ding)(ding)期的(de)(de)(de)(de)(de)檢(jian)(jian)查(cha)和(he)維(wei)(wei)(wei)修(xiu)(xiu)有(you)力利于差(cha)(cha)動(dong)變壓(ya)(ya)器(qi)(qi)(qi)(qi)性能(neng)的(de)(de)(de)(de)(de)維(wei)(wei)(wei)持和(he)正常(chang)(chang)運(yun)行(xing),從而(er)減少故障的(de)(de)(de)(de)(de)發(fa)生,延長使(shi)(shi)(shi)用(yong)(yong)壽命(ming)。檢(jian)(jian)查(cha)和(he)維(wei)(wei)(wei)修(xiu)(xiu)步(bu)驟和(he)方法是(shi)(shi)(shi)(shi)檢(jian)(jian)查(cha)傳(chuan)感(gan)器(qi)(qi)(qi)(qi)的(de)(de)(de)(de)(de)電(dian)(dian)(dian)源電(dian)(dian)(dian)壓(ya)(ya)、輸出電(dian)(dian)(dian)壓(ya)(ya)和(he)工作性能(neng)。主要(yao)有(you)五大操作步(bu)驟聽(ting)、摸、查(cha)、看和(he)聞(wen)。經(jing)驗豐富的(de)(de)(de)(de)(de)工作人員摸摸運(yun)行(xing)的(de)(de)(de)(de)(de)部(bu)位的(de)(de)(de)(de)(de)溫度(du)是(shi)(shi)(shi)(shi)否正常(chang)(chang),聽(ting)聽(ting)設備(bei)(bei)運(yun)行(xing)的(de)(de)(de)(de)(de)聲音(yin)是(shi)(shi)(shi)(shi)否有(you)異常(chang)(chang),查(cha)看傳(chuan)感(gan)器(qi)(qi)(qi)(qi)的(de)(de)(de)(de)(de)系統是(shi)(shi)(shi)(shi)否有(you)問(wen)題(ti)和(he)設備(bei)(bei)運(yun)行(xing)參數符合規(gui)(gui)定(ding)(ding)(ding)的(de)(de)(de)(de)(de)程度(du),聞(wen)聞(wen)運(yun)行(xing)部(bu)位是(shi)(shi)(shi)(shi)否有(you)異味。再(zai)采用(yong)(yong)先(xian)進(jin)(jin)的(de)(de)(de)(de)(de)科學儀(yi)(yi)表儀(yi)(yi)器(qi)(qi)(qi)(qi)來精確(que)的(de)(de)(de)(de)(de)測試(shi)出傳(chuan)感(gan)器(qi)(qi)(qi)(qi)的(de)(de)(de)(de)(de)運(yun)行(xing)情況。維(wei)(wei)(wei)修(xiu)(xiu)的(de)(de)(de)(de)(de)方法主要(yao)是(shi)(shi)(shi)(shi)根據(ju)設備(bei)(bei)的(de)(de)(de)(de)(de)使(shi)(shi)(shi)用(yong)(yong)情況,參考(kao)有(you)關(guan)維(wei)(wei)(wei)修(xiu)(xiu)周(zhou)期、維(wei)(wei)(wei)修(xiu)(xiu)工作的(de)(de)(de)(de)(de)計(ji)劃日期和(he)大致維(wei)(wei)(wei)修(xiu)(xiu)工作量(liang)和(he)設備(bei)(bei)制(zhi)度(du)。然后(hou)再(zai)依據(ju)每(mei)次(ci)維(wei)(wei)(wei)修(xiu)(xiu)前的(de)(de)(de)(de)(de)準(zhun)備(bei)(bei)制(zhi)定(ding)(ding)(ding)出確(que)切的(de)(de)(de)(de)(de)工作安排,最終(zhong)制(zhi)定(ding)(ding)(ding)出詳細(xi)而(er)規(gui)(gui)范的(de)(de)(de)(de)(de)維(wei)(wei)(wei)修(xiu)(xiu)方案。
3 結語
綜(zong)上所述,差(cha)動(dong)變(bian)壓器(qi)傳感器(qi)是(shi)非常重要的(de)(de)(de)(de)器(qi)材,在(zai)講究速度和(he)高(gao)質(zhi)量的(de)(de)(de)(de)社會,差(cha)動(dong)變(bian)壓器(qi)傳感器(qi)靈活性(xing)、高(gao)效(xiao)性(xing)和(he)靈敏性(xing)就顯得非常重要,這(zhe)些優點(dian)是(shi)非常符(fu)合時展(zhan)的(de)(de)(de)(de)步伐和(he)潮流的(de)(de)(de)(de),具有很大的(de)(de)(de)(de)前景。且(qie)正確的(de)(de)(de)(de)使(shi)用(yong)差(cha)動(dong)變(bian)壓器(qi)傳感器(qi)不(bu)僅可(ke)以輔助設(she)(she)計者進(jin)行高(gao)效(xiao)的(de)(de)(de)(de)設(she)(she)計工作,提高(gao)現階段的(de)(de)(de)(de)工作效(xiao)率(lv)、降低生產(chan)成本,還(huan)可(ke)以推進(jin)差(cha)動(dong)變(bian)壓器(qi)的(de)(de)(de)(de)發展(zhan)和(he)進(jin)步。重視差(cha)動(dong)變(bian)壓器(qi)傳感器(qi)的(de)(de)(de)(de)應用(yong)和(he)發展(zhan),有利于推動(dong)科學技術(shu)的(de)(de)(de)(de)發展(zhan)、增強我(wo)國的(de)(de)(de)(de)綜(zong)合實力、和(he)實現科學技術(shu)為(wei)立國之本的(de)(de)(de)(de)目標(biao)。
【參考文獻】
篇5
關鍵詞:變壓(ya)器 呼吸器 硅膠(jiao) 瓦斯保(bao)護
1 變壓器的(de)基本(ben)結構
變(bian)壓(ya)器(qi)(qi)的(de)基(ji)本(ben)結構由器(qi)(qi)身(shen)、油(you)(you)箱(xiang)、冷卻裝(zhuang)置(zhi)(zhi)、保(bao)護(hu)裝(zhuang)置(zhi)(zhi)、出線(xian)裝(zhuang)置(zhi)(zhi)及(ji)變(bian)壓(ya)器(qi)(qi)油(you)(you)組(zu)(zu)成。其(qi)中器(qi)(qi)身(shen)包(bao)括(kuo)(kuo)鐵芯、繞組(zu)(zu)、絕(jue)緣、引線(xian)及(ji)分接開關(guan);油(you)(you)箱(xiang)包(bao)括(kuo)(kuo)油(you)(you)箱(xiang)本(ben)體及(ji)附(fu)件(jian);保(bao)護(hu)裝(zhuang)置(zhi)(zhi)包(bao)括(kuo)(kuo)油(you)(you)枕、油(you)(you)表、安全氣道、呼(hu)吸器(qi)(qi)、測(ce)溫元件(jian)、凈(jing)油(you)(you)器(qi)(qi)、繼電器(qi)(qi)等;出線(xian)裝(zhuang)置(zhi)(zhi)包(bao)括(kuo)(kuo)高、中、低壓(ya)瓷套管(guan)等。油(you)(you)枕一(yi)(yi)般分為兩(liang)種形(xing)式:膠(jiao)囊式油(you)(you)枕和隔(ge)膜(mo)式油(you)(you)枕,其(qi)作(zuo)(zuo)用(yong)一(yi)(yi)致,膠(jiao)囊或隔(ge)膜(mo)的(de)主要作(zuo)(zuo)用(yong)就是將油(you)(you)和空氣隔(ge)絕(jue)。油(you)(you)枕膠(jiao)囊內的(de)氣體通過呼(hu)吸器(qi)(qi)與外(wai)界進行交(jiao)換。
2 呼(hu)吸器的(de)結構與在變壓器中的(de)作用
呼吸(xi)(xi)器(qi)(qi)(qi)也叫吸(xi)(xi)濕器(qi)(qi)(qi),是主變(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)(本文所指變(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)均為油(you)(you)浸式(shi)電力變(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi))的(de)一個附屬安全保(bao)護裝(zhuang)置,呼吸(xi)(xi)器(qi)(qi)(qi)安裝(zhuang)在(zai)油(you)(you)枕與空(kong)氣(qi)連通的(de)管(guan)道末端(duan),由(you)導氣(qi)管(guan)、容器(qi)(qi)(qi)及油(you)(you)杯組成,容器(qi)(qi)(qi)內(nei)(nei)裝(zhuang)有硅膠,油(you)(you)杯內(nei)(nei)裝(zhuang)有絕緣(yuan)油(you)(you)。呼吸(xi)(xi)器(qi)(qi)(qi)能(neng)使(shi)(shi)變(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)本身(shen)內(nei)(nei)的(de)空(kong)氣(qi)通過呼吸(xi)(xi)器(qi)(qi)(qi)與外界空(kong)氣(qi)相通,保(bao)持器(qi)(qi)(qi)身(shen)內(nei)(nei)外氣(qi)壓(ya)(ya)(ya)(ya)(ya)相等(deng),防止高溫(wen)(wen)天氣(qi)或(huo)滿負荷運行時(shi)變(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)油(you)(you)因升(sheng)溫(wen)(wen)膨脹,內(nei)(nei)部壓(ya)(ya)(ya)(ya)(ya)力升(sheng)高無法釋放造(zao)成變(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)噴油(you)(you)。二是通過呼吸(xi)(xi)器(qi)(qi)(qi)內(nei)(nei)裝(zhuang)的(de)干燥劑吸(xi)(xi)收(shou)進入變(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)內(nei)(nei)空(kong)氣(qi)中(zhong)的(de)水分,使(shi)(shi)變(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)絕緣(yuan)油(you)(you)保(bao)持良(liang)好的(de)電氣(qi)性能(neng),防止潮濕空(kong)氣(qi)直接進入變(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)油(you)(you)枕內(nei)(nei),使(shi)(shi)變(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)油(you)(you)受潮,降低(di)或(huo)破壞變(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)的(de)絕緣(yuan)強度(du),以致繞(rao)組燒毀(hui)。
如圖一所示(shi),空氣(qi)流動(dong)的過程(cheng):
油枕――呼(hu)吸器聯管――玻(bo)璃(li)罩(zhao)――玻(bo)璃(li)筒――油封片――集(ji)油杯(bei)――氣(qi)孔――大(da)氣(qi),圖為呼(hu)吸器呼(hu)氣(qi)時動作效果。
3 硅膠的作用
3.1 硅膠(jiao)(Silica gel;Silica)也被稱為(wei)硅橡(xiang)膠(jiao),是一種(zhong)活性(xing)吸附材料,它無毒無味(wei),性(xing)質穩定,基本上(shang)不(bu)(bu)與(yu)任(ren)何(he)物(wu)質發生反應,除了強(qiang)堿(jian)、氫氟酸等,而且不(bu)(bu)溶于任(ren)何(he)溶劑。因為(wei)制造工(gong)藝的(de)不(bu)(bu)同(tong),不(bu)(bu)同(tong)的(de)硅膠(jiao)它的(de)結(jie)構也不(bu)(bu)同(tong)。硅膠(jiao)的(de)物(wu)理結(jie)構和化學成分與(yu)其他材料有(you)很大的(de)不(bu)(bu)同(tong),形成其獨(du)有(you)的(de)特(te)點:較(jiao)(jiao)高的(de)吸附性(xing)能、較(jiao)(jiao)好的(de)熱穩定性(xing)、機械強(qiang)度較(jiao)(jiao)高。
3.2 主要(yao)用(yong)途:主要(yao)作用(yong)是吸潮防銹,被廣泛(fan)應用(yong)在密閉(bi)條件下的(de)(de)設備、儀表。配合普通(tong)的(de)(de)硅膠干(gan)燥劑(ji)(ji)使用(yong),能顯示干(gan)燥劑(ji)(ji)的(de)(de)吸潮程度(du)和分(fen)析(xi)環(huan)境(jing)的(de)(de)相對濕(shi)度(du)等。也(ye)可以是包裝用(yong)的(de)(de)干(gan)燥劑(ji)(ji),被應用(yong)在儀器(qi)、食品、皮(pi)革、日用(yong)品等方(fang)面。
3.3 工業油(you)變(bian)壓器(qi)中用(yong)的(de)較多的(de)是藍(lan)(lan)色硅膠,因為它除了有(you)吸附(fu)防潮的(de)作用(yong)外,還(huan)(huan)可以(yi)隨著吸濕(shi)量(liang)的(de)增(zeng)加(jia),而(er)改變(bian)自身的(de)顏色,由(you)藍(lan)(lan)變(bian)紫,再(zai)變(bian)淺(qian)紅(hong),不僅可以(yi)顯示環境(jing)的(de)濕(shi)度,也直觀顯示是否還(huan)(huan)有(you)防潮作用(yong),還(huan)(huan)可以(yi)判斷何時失去(qu)效應,及時更換新的(de)硅膠。
4 瓦斯保護的定義和工作(zuo)原理
4.1 瓦斯(si)保護是(shi)油浸是(shi)變壓(ya)器的(de)一(yi)種保護裝置,是(shi)變壓(ya)器內(nei)部故障的(de)主要保護元件(jian)。如(ru)圖三(san)所示,安裝在變壓(ya)器箱蓋和儲(chu)油柜的(de)聯管上,當油浸式(shi)變壓(ya)器內(nei)部發生(sheng)故障時,產(chan)生(sheng)的(de)電弧大量放熱,將變壓(ya)器內(nei)部的(de)絕緣材料受熱分解產(chan)生(sheng)大量的(de)氣體,就有(you)可能(neng)造成油流沖動,從而使繼電器的(de)接點動作,通過保護回路,動作于變壓(ya)器重(zhong)瓦斯(si)調整。
4.2 目前開(kai)口(kou)杯擋(dang)板(ban)式瓦斯繼(ji)電(dian)(dian)器是(shi)我(wo)國大部分電(dian)(dian)力(li)(li)(li)企業應用的(de)(de)(de)(de)繼(ji)電(dian)(dian)器,它的(de)(de)(de)(de)結構主(zhu)要是(shi)上(shang)(shang)下(xia)兩(liang)個開(kai)口(kou)杯和平衡(heng)錘(chui)。上(shang)(shang)下(xia)兩(liang)個開(kai)口(kou)杯都浸在(zai)(zai)油(you)(you)(you)(you)(you)里(li),平衡(heng)錘(chui)產(chan)(chan)生(sheng)的(de)(de)(de)(de)力(li)(li)(li)矩(ju)(ju)大于(yu)開(kai)口(kou)杯在(zai)(zai)油(you)(you)(you)(you)(you)內的(de)(de)(de)(de)重(zhong)力(li)(li)(li)所產(chan)(chan)生(sheng)的(de)(de)(de)(de)力(li)(li)(li)矩(ju)(ju),所以(yi)開(kai)口(kou)杯向上(shang)(shang)傾斜(xie),不(bu)能觸(chu)發繼(ji)電(dian)(dian)器接(jie)點動作。但是(shi)如果變(bian)壓器油(you)(you)(you)(you)(you)箱(xiang)內部發生(sheng)故障,絕(jue)緣(yuan)油(you)(you)(you)(you)(you)會被分解,形成少量(liang)的(de)(de)(de)(de)氣體(ti),因為(wei)(wei)變(bian)壓器布置傾斜(xie),從而(er)使氣體(ti)逐漸聚集在(zai)(zai)繼(ji)電(dian)(dian)器的(de)(de)(de)(de)上(shang)(shang)部,油(you)(you)(you)(you)(you)面下(xia)降(jiang),從而(er)上(shang)(shang)開(kai)口(kou)杯漏(lou)出(chu)油(you)(you)(you)(you)(you)面,浮(fu)子(zi)浮(fu)力(li)(li)(li)減小。平衡(heng)錘(chui)產(chan)(chan)生(sheng)的(de)(de)(de)(de)力(li)(li)(li)矩(ju)(ju)小于(yu)開(kai)口(kou)杯在(zai)(zai)油(you)(you)(you)(you)(you)內的(de)(de)(de)(de)重(zhong)力(li)(li)(li)所產(chan)(chan)生(sheng)的(de)(de)(de)(de)力(li)(li)(li)矩(ju)(ju),從而(er)使上(shang)(shang)開(kai)口(kou)杯的(de)(de)(de)(de)觸(chu)點動作,觸(chu)發輕(qing)瓦斯保護動作,保護回路(lu)發出(chu)信(xin)號。當內部故障嚴重(zhong),大量(liang)放熱分解絕(jue)緣(yuan)油(you)(you)(you)(you)(you)產(chan)(chan)生(sheng)大量(liang)的(de)(de)(de)(de)氣體(ti)時,油(you)(you)(you)(you)(you)流直接(jie)沖擊下(xia)開(kai)口(kou)杯的(de)(de)(de)(de)擋(dang)板(ban),使下(xia)開(kai)口(kou)杯觸(chu)點動作,觸(chu)發變(bian)壓器重(zhong)瓦斯保護動作。所以(yi),當瓦斯繼(ji)電(dian)(dian)器及(ji)瓦斯保護回路(lu)接(jie)線正常,回路(lu)沒有(you)問題的(de)(de)(de)(de)時候,若瓦斯保護動作,可(ke)能有(you)以(yi)下(xia)原(yuan)因:①因為(wei)(wei)發生(sheng)故障,在(zai)(zai)變(bian)壓器油(you)(you)(you)(you)(you)箱(xiang)里(li)形成一些(xie)氣體(ti),并從油(you)(you)(you)(you)(you)箱(xiang)流向油(you)(you)(you)(you)(you)枕;②變(bian)壓器油(you)(you)(you)(you)(you)箱(xiang)到油(you)(you)(you)(you)(you)枕之(zhi)間(jian)的(de)(de)(de)(de)連接(jie)管道上(shang)(shang)出(chu)現快(kuai)速油(you)(you)(you)(you)(you)流;③變(bian)壓器油(you)(you)(you)(you)(you)位下(xia)降(jiang)。
5 在主(zhu)變(bian)壓器更換(huan)呼(hu)吸器硅膠時,對瓦斯(si)保護的影響
5.1 對(dui)在(zai)(zai)運(yun)(yun)行(xing)中(zhong)的主(zhu)變壓(ya)(ya)器更換呼(hu)吸(xi)器硅(gui)膠,需要將(jiang)重瓦(wa)(wa)斯(si)(si)保(bao)(bao)護(hu)(hu)由跳(tiao)閘改投發信,這(zhe)一點(dian)(dian)(dian)基本上沒有什(shen)么異議,分歧比較(jiao)大的是在(zai)(zai)硅(gui)膠更換完畢后(hou)什(shen)么時候(hou)投入(ru)重瓦(wa)(wa)斯(si)(si)保(bao)(bao)護(hu)(hu)。一種觀點(dian)(dian)(dian)認為(wei)(wei)變壓(ya)(ya)器需要經過24小(xiao)時的試運(yun)(yun)行(xing)正常后(hou),方(fang)可將(jiang)重瓦(wa)(wa)斯(si)(si)保(bao)(bao)護(hu)(hu)投入(ru)跳(tiao)閘,因(yin)為(wei)(wei)在(zai)(zai)更換完主(zhu)變壓(ya)(ya)器呼(hu)吸(xi)器硅(gui)膠后(hou),還有可能造成瓦(wa)(wa)期(qi)保(bao)(bao)護(hu)(hu)的誤動(dong)作;另一種觀點(dian)(dian)(dian)是主(zhu)變在(zai)(zai)更換完硅(gui)膠后(hou)對(dui)瓦(wa)(wa)斯(si)(si)保(bao)(bao)護(hu)(hu)并無影響,可直接(jie)恢復正常,將(jiang)重瓦(wa)(wa)斯(si)(si)保(bao)(bao)護(hu)(hu)投入(ru)跳(tiao)閘。
5.2 主變呼吸(xi)(xi)器(qi)(qi)(qi)(qi)更(geng)換(huan)(huan)硅(gui)(gui)膠(jiao)(jiao)(jiao)工(gong)作結束后,對瓦斯(si)保護(hu)的(de)影響(xiang)分析:①雖然(ran)在更(geng)換(huan)(huan)呼吸(xi)(xi)器(qi)(qi)(qi)(qi)硅(gui)(gui)膠(jiao)(jiao)(jiao)的(de)過程中,通過連(lian)接(jie)管(guan)變壓(ya)器(qi)(qi)(qi)(qi)的(de)油(you)枕(zhen)膠(jiao)(jiao)(jiao)囊內的(de)氣體與大氣進(jin)(jin)行(xing)了直接(jie)接(jie)觸(chu),但(dan)是變壓(ya)器(qi)(qi)(qi)(qi)油(you)箱(xiang)里(li)面并(bing)沒有進(jin)(jin)入氣體,依據(ju)瓦斯(si)繼(ji)電(dian)器(qi)(qi)(qi)(qi)動作原(yuan)理可知,不會(hui)(hui)使(shi)其動作;②更(geng)換(huan)(huan)硅(gui)(gui)膠(jiao)(jiao)(jiao)工(gong)作并(bing)不會(hui)(hui)使(shi)油(you)箱(xiang)到油(you)枕(zhen)之間(jian)的(de)連(lian)接(jie)管(guan)道上出(chu)現大量的(de)油(you)流(liu)動,也不會(hui)(hui)觸(chu)發(fa)瓦斯(si)繼(ji)電(dian)器(qi)(qi)(qi)(qi)動作;③更(geng)換(huan)(huan)硅(gui)(gui)膠(jiao)(jiao)(jiao)工(gong)作,不會(hui)(hui)影響(xiang)瓦斯(si)繼(ji)電(dian)器(qi)(qi)(qi)(qi),也不會(hui)(hui)使(shi)油(you)箱(xiang)油(you)位大幅度下降;④更(geng)換(huan)(huan)呼吸(xi)(xi)器(qi)(qi)(qi)(qi)硅(gui)(gui)膠(jiao)(jiao)(jiao)時(shi)要對呼吸(xi)(xi)器(qi)(qi)(qi)(qi)進(jin)(jin)行(xing)清潔和對油(you)封(feng)進(jin)(jin)行(xing)換(huan)(huan)油(you)。
5.3 主變(bian)(bian)壓器是發(fa)(fa)電廠及變(bian)(bian)電站的(de)(de)重要組(zu)成(cheng)(cheng)部門也是重要的(de)(de)設備(bei),它的(de)(de)故障給安全運行(xing)帶來很大的(de)(de)威脅。因此(ci)保(bao)護應該及時(shi)投入運行(xing),避免長(chang)時(shi)間退出運行(xing),以(yi)免在進(jin)行(xing)檢修工作(zuo)過程(cheng)中(zhong),發(fa)(fa)生保(bao)護動作(zuo),而未觸發(fa)(fa)損壞(huai)變(bian)(bian)壓器。因此(ci)主變(bian)(bian)更換硅(gui)膠結束后(hou),應盡快將保(bao)護恢復正(zheng)(zheng)常(chang)運行(xing)。以(yi)下幾種情(qing)(qing)況可能發(fa)(fa)生瓦(wa)(wa)斯保(bao)護誤動:如果呼吸(xi)器上(shang)口的(de)(de)橡膠墊子被壓偏,在更換過程(cheng)中(zhong)可能造成(cheng)(cheng)膠囊或(huo)隔(ge)膜被隔(ge)絕的(de)(de)氣壓發(fa)(fa)生變(bian)(bian)化(hua),造成(cheng)(cheng)油流(liu)動而觸發(fa)(fa)瓦(wa)(wa)斯保(bao)護動作(zuo),這(zhe)種情(qing)(qing)況較為特殊,除非(fei)是呼吸(xi)器長(chang)時(shi)間無法進(jin)行(xing)正(zheng)(zheng)常(chang)呼吸(xi),且長(chang)達一年以(yi)上(shang)不進(jin)行(xing)硅(gui)膠更換,正(zheng)(zheng)常(chang)巡視中(zhong)未發(fa)(fa)現有(you)氣泡正(zheng)(zheng)常(chang)冒出,或(huo)者上(shang)次更換吸(xi)濕(shi)劑時(shi)與本次溫(wen)差非(fei)常(chang)大,造成(cheng)(cheng)的(de)(de)油壓變(bian)(bian)化(hua)使膠囊或(huo)隔(ge)膜中(zhong)的(de)(de)壓力變(bian)(bian)化(hua)形成(cheng)(cheng)油流(liu)流(liu)動達到瓦(wa)(wa)斯的(de)(de)動作(zuo)值(zhi)。以(yi)上(shang)事件概率極小,因此(ci)更換硅(gui)膠的(de)(de)工作(zuo)完畢后(hou)就(jiu)應將重瓦(wa)(wa)斯保(bao)護改投跳閘(zha)。
參考文獻:
[1]大(da)唐魯北發電(dian)有限責(ze)任公(gong)司2*330MW亞臨界機組(zu)集控運行規程.
篇6
關鍵(jian)詞:電機學(xue);教(jiao)學(xue)模(mo)式;內容規劃;課程改革(ge)
作者簡(jian)介:程江洲(1979-),男(nan),湖(hu)北宜(yi)昌(chang)(chang)人,三峽(xia)大學電(dian)氣與新能源學院(yuan),講(jiang)(jiang)師;肖建修(1965-),男(nan),湖(hu)南(nan)漣源人,三峽(xia)大學電(dian)氣與新能源學院(yuan),講(jiang)(jiang)師。(湖(hu)北?宜(yi)昌(chang)(chang)?443002)
中圖分類(lei)號(hao):G642.0?????文獻標識碼:A?????文章編號(hao):1007-0079(2012)27-0074-02
“電(dian)機學(xue)”課(ke)(ke)程是電(dian)氣工程及自動化(hua)類專業重(zhong)(zhong)(zhong)要的(de)(de)專業基礎(chu)課(ke)(ke),在人(ren)才(cai)培(pei)養的(de)(de)知識結(jie)(jie)構和(he)課(ke)(ke)程體(ti)系中具有(you)重(zhong)(zhong)(zhong)要地位(wei)和(he)作(zuo)用,由于本課(ke)(ke)程不僅涉及各種電(dian)機復雜的(de)(de)空間結(jie)(jie)構,還涉及電(dian)流和(he)磁場(chang)在空間的(de)(de)分布(bu),以及鐵磁材料的(de)(de)非線性等問題,一(yi)(yi)直是一(yi)(yi)門典型的(de)(de)難(nan)教難(nan)學(xue)的(de)(de)課(ke)(ke)程,而(er)且該課(ke)(ke)程對前(qian)期(qi)(qi)課(ke)(ke)程的(de)(de)要求高,對后(hou)續課(ke)(ke)程的(de)(de)影(ying)響大,所以它(ta)成為學(xue)生大學(xue)期(qi)(qi)間重(zhong)(zhong)(zhong)要、艱難(nan)的(de)(de)一(yi)(yi)個(ge)學(xue)習關口。如何提高該課(ke)(ke)程教學(xue)質(zhi)量和(he)教學(xue)效果,值得(de)我們從多方面入手研究和(he)解決。[1]
一、“電機學(xue)”教學(xue)現狀
目前“電(dian)機(ji)學(xue)(xue)”課(ke)程是(shi)三峽(xia)大(da)學(xue)(xue)(以下(xia)簡稱“我(wo)校”)電(dian)氣工程及自動化類專業(ye)一門非常重(zhong)要的(de)(de)(de)(de)學(xue)(xue)位課(ke)程,占6個(ge)學(xue)(xue)分(fen)(fen)(fen),總學(xue)(xue)時96學(xue)(xue)時,其中(zhong)理論(lun)課(ke)84學(xue)(xue)時,實驗12學(xue)(xue)時。授(shou)課(ke)內(nei)容(rong)包括(kuo)磁(ci)路的(de)(de)(de)(de)基本概述、變壓(ya)(ya)器(qi)、交流(liu)繞組(zu)的(de)(de)(de)(de)共(gong)同理論(lun)、同步(bu)電(dian)機(ji)、異步(bu)電(dian)機(ji)、直流(liu)電(dian)機(ji),共(gong)6個(ge)部分(fen)(fen)(fen)的(de)(de)(de)(de)內(nei)容(rong),學(xue)(xue)生需(xu)要在(zai)1個(ge)學(xue)(xue)期內(nei)學(xue)(xue)習變壓(ya)(ya)器(qi)、同步(bu)電(dian)機(ji)、異步(bu)電(dian)機(ji)及直流(liu)電(dian)機(ji)4大(da)類型的(de)(de)(de)(de)電(dian)機(ji),而這(zhe)4類電(dian)機(ji)又各自具備不同的(de)(de)(de)(de)結構和(he)分(fen)(fen)(fen)析方法,同時我(wo)們的(de)(de)(de)(de)授(shou)課(ke)學(xue)(xue)時為每(mei)周6個(ge)學(xue)(xue)時,這(zhe)些(xie)實際情況是(shi)學(xue)(xue)生理解(jie)和(he)吸(xi)收(shou)電(dian)機(ji)學(xue)(xue)內(nei)容(rong)的(de)(de)(de)(de)最大(da)障礙。初步(bu)統(tong)計了(le)近幾(ji)個(ge)學(xue)(xue)期電(dian)機(ji)學(xue)(xue)考試的(de)(de)(de)(de)成績,2009年平(ping)均分(fen)(fen)(fen)為61.22分(fen)(fen)(fen),2010年平(ping)均分(fen)(fen)(fen)為62.04分(fen)(fen)(fen),2011年平(ping)均分(fen)(fen)(fen)為52.78分(fen)(fen)(fen),雖然這(zhe)幾(ji)個(ge)學(xue)(xue)期我(wo)們經過(guo)了(le)諸多努(nu)力,但本課(ke)程的(de)(de)(de)(de)教學(xue)(xue)效果仍然沒有明顯改(gai)善,因此“電(dian)機(ji)學(xue)(xue)”課(ke)程的(de)(de)(de)(de)改(gai)革迫在(zai)眉(mei)睫。
二、“電機學”課程改革措施
在(zai)參考了(le)(le)華(hua)北電力大(da)學(xue)(xue)(xue)(xue)(xue)(xue)、華(hua)中(zhong)科技大(da)學(xue)(xue)(xue)(xue)(xue)(xue)等(deng)國內多個(ge)(ge)知名高(gao)校的“電機(ji)學(xue)(xue)(xue)(xue)(xue)(xue)”教學(xue)(xue)(xue)(xue)(xue)(xue)模式的基礎上(shang),我校“電機(ji)學(xue)(xue)(xue)(xue)(xue)(xue)”課(ke)(ke)程組提出了(le)(le)在(zai)總學(xue)(xue)(xue)(xue)(xue)(xue)時不變的情況(kuang)下,將“電機(ji)學(xue)(xue)(xue)(xue)(xue)(xue)”課(ke)(ke)程安排在(zai)兩個(ge)(ge)學(xue)(xue)(xue)(xue)(xue)(xue)期授課(ke)(ke),同時對其內容(rong)、教學(xue)(xue)(xue)(xue)(xue)(xue)方式、教學(xue)(xue)(xue)(xue)(xue)(xue)手段等(deng)進行了(le)(le)規劃和改革。
1.教學內容的規劃與改革
根據我(wo)校的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)氣工程(cheng)(cheng)及自動化類專業(ye)的(de)(de)課(ke)(ke)(ke)(ke)程(cheng)(cheng)安(an)(an)排(pai),電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)學(xue)(xue)(xue)(xue)(xue)(xue)(xue)的(de)(de)學(xue)(xue)(xue)(xue)(xue)(xue)(xue)習(xi)需要(yao)先修“高等(deng)數(shu)(shu)學(xue)(xue)(xue)(xue)(xue)(xue)(xue)”、“大學(xue)(xue)(xue)(xue)(xue)(xue)(xue)物理”、“電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)原(yuan)(yuan)(yuan)理”、“電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)子(zi)技術(shu)基礎(chu)”等(deng)課(ke)(ke)(ke)(ke)程(cheng)(cheng),“高等(deng)數(shu)(shu)學(xue)(xue)(xue)(xue)(xue)(xue)(xue)”分(fen)兩(liang)個(ge)學(xue)(xue)(xue)(xue)(xue)(xue)(xue)期(qi)(qi)(qi)(qi)授(shou)(shou)(shou)課(ke)(ke)(ke)(ke),分(fen)別(bie)(bie)安(an)(an)排(pai)在(zai)(zai)(zai)第(di)(di)一(yi)、二學(xue)(xue)(xue)(xue)(xue)(xue)(xue)期(qi)(qi)(qi)(qi);“大學(xue)(xue)(xue)(xue)(xue)(xue)(xue)物理”分(fen)兩(liang)個(ge)學(xue)(xue)(xue)(xue)(xue)(xue)(xue)期(qi)(qi)(qi)(qi)授(shou)(shou)(shou)課(ke)(ke)(ke)(ke),分(fen)別(bie)(bie)安(an)(an)排(pai)在(zai)(zai)(zai)第(di)(di)二、三(san)學(xue)(xue)(xue)(xue)(xue)(xue)(xue)期(qi)(qi)(qi)(qi);“電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)原(yuan)(yuan)(yuan)理”一(yi)個(ge)學(xue)(xue)(xue)(xue)(xue)(xue)(xue)期(qi)(qi)(qi)(qi)授(shou)(shou)(shou)課(ke)(ke)(ke)(ke),安(an)(an)排(pai)在(zai)(zai)(zai)第(di)(di)二學(xue)(xue)(xue)(xue)(xue)(xue)(xue)期(qi)(qi)(qi)(qi);“電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)子(zi)技術(shu)基礎(chu)”課(ke)(ke)(ke)(ke)程(cheng)(cheng)也進(jin)行了(le)改(gai)革,分(fen)在(zai)(zai)(zai)兩(liang)個(ge)學(xue)(xue)(xue)(xue)(xue)(xue)(xue)期(qi)(qi)(qi)(qi)授(shou)(shou)(shou)課(ke)(ke)(ke)(ke),分(fen)別(bie)(bie)安(an)(an)排(pai)在(zai)(zai)(zai)第(di)(di)三(san)、四學(xue)(xue)(xue)(xue)(xue)(xue)(xue)期(qi)(qi)(qi)(qi);針對以上的(de)(de)課(ke)(ke)(ke)(ke)程(cheng)(cheng)安(an)(an)排(pai),“電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)學(xue)(xue)(xue)(xue)(xue)(xue)(xue)”由原(yuan)(yuan)(yuan)先第(di)(di)五(wu)學(xue)(xue)(xue)(xue)(xue)(xue)(xue)期(qi)(qi)(qi)(qi)授(shou)(shou)(shou)課(ke)(ke)(ke)(ke)改(gai)為第(di)(di)四學(xue)(xue)(xue)(xue)(xue)(xue)(xue)期(qi)(qi)(qi)(qi)和(he)第(di)(di)五(wu)學(xue)(xue)(xue)(xue)(xue)(xue)(xue)期(qi)(qi)(qi)(qi)分(fen)別(bie)(bie)授(shou)(shou)(shou)課(ke)(ke)(ke)(ke),“電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)子(zi)技術(shu)基礎(chu)”課(ke)(ke)(ke)(ke)程(cheng)(cheng)在(zai)(zai)(zai)第(di)(di)三(san)學(xue)(xue)(xue)(xue)(xue)(xue)(xue)期(qi)(qi)(qi)(qi)講授(shou)(shou)(shou)模擬電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)子(zi)技術(shu),到了(le)第(di)(di)四學(xue)(xue)(xue)(xue)(xue)(xue)(xue)期(qi)(qi)(qi)(qi)講授(shou)(shou)(shou)數(shu)(shu)字電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)子(zi)技術(shu),這樣“電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)學(xue)(xue)(xue)(xue)(xue)(xue)(xue)”在(zai)(zai)(zai)第(di)(di)四學(xue)(xue)(xue)(xue)(xue)(xue)(xue)期(qi)(qi)(qi)(qi)講授(shou)(shou)(shou)時,學(xue)(xue)(xue)(xue)(xue)(xue)(xue)生已(yi)經學(xue)(xue)(xue)(xue)(xue)(xue)(xue)過了(le)“高等(deng)數(shu)(shu)學(xue)(xue)(xue)(xue)(xue)(xue)(xue)”、“大學(xue)(xue)(xue)(xue)(xue)(xue)(xue)物理”、“電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)原(yuan)(yuan)(yuan)理”及“模擬電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)子(zi)技術(shu)”,具備了(le)相應的(de)(de)基礎(chu),不影響“電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)學(xue)(xue)(xue)(xue)(xue)(xue)(xue)”的(de)(de)學(xue)(xue)(xue)(xue)(xue)(xue)(xue)習(xi),此外由于“電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)學(xue)(xue)(xue)(xue)(xue)(xue)(xue)”為專業(ye)基礎(chu)課(ke)(ke)(ke)(ke),后續專業(ye)課(ke)(ke)(ke)(ke)為“電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)力系統分(fen)析”,我(wo)們(men)在(zai)(zai)(zai)課(ke)(ke)(ke)(ke)程(cheng)(cheng)群的(de)(de)改(gai)革中,對“電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)力系統分(fen)析”也進(jin)行了(le)改(gai)革,分(fen)在(zai)(zai)(zai)第(di)(di)五(wu)、六兩(liang)個(ge)學(xue)(xue)(xue)(xue)(xue)(xue)(xue)期(qi)(qi)(qi)(qi)授(shou)(shou)(shou)課(ke)(ke)(ke)(ke),因此,根據課(ke)(ke)(ke)(ke)程(cheng)(cheng)群及專業(ye)課(ke)(ke)(ke)(ke)的(de)(de)要(yao)求,我(wo)們(men)對“電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)學(xue)(xue)(xue)(xue)(xue)(xue)(xue)”(上)和(he)“電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)學(xue)(xue)(xue)(xue)(xue)(xue)(xue)”(下)的(de)(de)授(shou)(shou)(shou)課(ke)(ke)(ke)(ke)課(ke)(ke)(ke)(ke)時和(he)內(nei)容做了(le)如下安(an)(an)排(pai):
(1)“電(dian)機學”(上)的(de)授課(ke)(ke)課(ke)(ke)時(shi)及內容:
1)緒論(4學時)。了(le)解(jie)本課程的(de)(de)(de)性(xing)質(zhi)和(he)(he)任務(wu);了(le)解(jie)電機在國(guo)民經濟(ji)中(zhong)的(de)(de)(de)地位(wei)、作用和(he)(he)國(guo)內外(wai)的(de)(de)(de)發展概況;熟悉和(he)(he)鞏固電機中(zhong)常(chang)用的(de)(de)(de)基本電磁(ci)定律和(he)(he)鐵磁(ci)材料(liao)特(te)性(xing);掌握簡單磁(ci)路的(de)(de)(de)計算(suan)方法。
2)變(bian)壓(ya)(ya)(ya)器(qi)(qi)(20學時)。了(le)解變(bian)壓(ya)(ya)(ya)器(qi)(qi)的(de)(de)(de)基(ji)本結構及(ji)(ji)用途,熟練掌(zhang)(zhang)握變(bian)壓(ya)(ya)(ya)器(qi)(qi)的(de)(de)(de)基(ji)本電磁關系及(ji)(ji)分(fen)析(xi)方法(fa)(fa);熟練掌(zhang)(zhang)握變(bian)壓(ya)(ya)(ya)器(qi)(qi)的(de)(de)(de)基(ji)本方程式、相(xiang)量圖和(he)等(deng)效(xiao)電路(lu);掌(zhang)(zhang)握變(bian)壓(ya)(ya)(ya)器(qi)(qi)的(de)(de)(de)磁路(lu)特(te)點、繞組連接(jie)方法(fa)(fa)和(he)連接(jie)組;掌(zhang)(zhang)握變(bian)壓(ya)(ya)(ya)器(qi)(qi)并聯運行(xing)的(de)(de)(de)條件,熟悉(xi)并聯運行(xing)時的(de)(de)(de)負載分(fen)配;掌(zhang)(zhang)握三相(xiang)變(bian)壓(ya)(ya)(ya)器(qi)(qi)不對稱運行(xing)的(de)(de)(de)分(fen)析(xi)方法(fa)(fa);了(le)解變(bian)壓(ya)(ya)(ya)器(qi)(qi)過電流瞬變(bian)過程的(de)(de)(de)物理概念;了(le)解各類特(te)殊變(bian)壓(ya)(ya)(ya)器(qi)(qi)的(de)(de)(de)用途和(he)結構特(te)點。
3)交流(liu)電(dian)(dian)機繞(rao)(rao)組(zu)(zu)(zu)的(de)(de)(de)共(gong)同理(li)論(lun)(10學時)。掌(zhang)握(wo)(wo)(wo)旋(xuan)轉電(dian)(dian)機的(de)(de)(de)基本工作(zuo)原(yuan)(yuan)理(li);了(le)解三相交流(liu)繞(rao)(rao)組(zu)(zu)(zu)的(de)(de)(de)構(gou)成原(yuan)(yuan)則和(he)(he)(he)(he)連接方法(fa),以三相雙層繞(rao)(rao)組(zu)(zu)(zu)為主;掌(zhang)握(wo)(wo)(wo)交流(liu)繞(rao)(rao)組(zu)(zu)(zu)電(dian)(dian)動(dong)(dong)勢(shi)(shi)的(de)(de)(de)分析(xi)和(he)(he)(he)(he)計(ji)算方法(fa),理(li)解繞(rao)(rao)組(zu)(zu)(zu)的(de)(de)(de)諧波電(dian)(dian)動(dong)(dong)勢(shi)(shi),了(le)解其削(xue)弱方法(fa);掌(zhang)握(wo)(wo)(wo)交流(liu)繞(rao)(rao)組(zu)(zu)(zu)磁(ci)(ci)動(dong)(dong)勢(shi)(shi)的(de)(de)(de)性質(zhi)及其表示和(he)(he)(he)(he)分析(xi)方法(fa);分清脈(mo)振磁(ci)(ci)動(dong)(dong)勢(shi)(shi)、圓形(xing)磁(ci)(ci)動(dong)(dong)勢(shi)(shi)和(he)(he)(he)(he)橢(tuo)圓形(xing)磁(ci)(ci)動(dong)(dong)勢(shi)(shi)的(de)(de)(de)區別及相互關(guan)系;了(le)解諧波磁(ci)(ci)動(dong)(dong)勢(shi)(shi)概念和(he)(he)(he)(he)漏(lou)磁(ci)(ci)通的(de)(de)(de)基本概念。
4)同(tong)(tong)(tong)步(bu)(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(22學(xue)時)。了解(jie)汽(qi)輪發(fa)(fa)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)和(he)(he)水輪發(fa)(fa)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)的(de)(de)基本結構;熟(shu)(shu)練掌握(wo)(wo)同(tong)(tong)(tong)步(bu)(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)樞反(fan)應(ying),著(zhu)重理解(jie)同(tong)(tong)(tong)步(bu)(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)氣隙磁場(chang)的(de)(de)形成、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)樞反(fan)應(ying)與負載性質的(de)(de)關系及(ji)其(qi)對電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)運(yun)(yun)行(xing)的(de)(de)影響;熟(shu)(shu)練掌握(wo)(wo)同(tong)(tong)(tong)步(bu)(bu)(bu)發(fa)(fa)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)方程式(shi)和(he)(he)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)勢相(xiang)量(liang)圖;著(zhu)重掌握(wo)(wo)同(tong)(tong)(tong)步(bu)(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)抗、繞組漏抗和(he)(he)短(duan)路比的(de)(de)物(wu)理概(gai)念和(he)(he)測(ce)定方法(fa)(fa);掌握(wo)(wo)同(tong)(tong)(tong)步(bu)(bu)(bu)發(fa)(fa)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)的(de)(de)運(yun)(yun)行(xing)特性、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)變化(hua)率及(ji)額定勵(li)磁電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流的(de)(de)磁勢法(fa)(fa)分析(xi)(xi)計(ji)算方法(fa)(fa);掌握(wo)(wo)同(tong)(tong)(tong)步(bu)(bu)(bu)發(fa)(fa)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)與大電(dian)(dian)(dian)(dian)(dian)(dian)(dian)網(wang)并列運(yun)(yun)行(xing)的(de)(de)條件和(he)(he)方法(fa)(fa);熟(shu)(shu)練掌握(wo)(wo)同(tong)(tong)(tong)步(bu)(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)的(de)(de)功角特性、V型曲線、并聯(lian)運(yun)(yun)行(xing)時有功和(he)(he)無功功率的(de)(de)調節(jie);了解(jie)靜態穩定的(de)(de)物(wu)理概(gai)念;掌握(wo)(wo)同(tong)(tong)(tong)步(bu)(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)各(ge)序(xu)阻抗的(de)(de)物(wu)理概(gai)念;學(xue)會運(yun)(yun)用對稱分量(liang)法(fa)(fa)分析(xi)(xi)三(san)相(xiang)同(tong)(tong)(tong)步(bu)(bu)(bu)發(fa)(fa)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)的(de)(de)不對稱運(yun)(yun)行(xing);理解(jie)三(san)相(xiang)突(tu)然(ran)短(duan)路的(de)(de)瞬態過程,理解(jie)瞬變和(he)(he)超瞬變電(dian)(dian)(dian)(dian)(dian)(dian)(dian)抗及(ji)各(ge)種時間常數的(de)(de)意義。
5)實(shi)(shi)驗教學內容(8學時)。包括(kuo)單相變壓器特(te)性(xing)及參(can)數測定、同(tong)步(bu)發電機的參(can)數測定、同(tong)步(bu)發電機運行特(te)性(xing)共三個實(shi)(shi)驗。
篇7
關(guan) 鍵 詞: 變電(dian)站220kV變壓器繼電(dian)保護
中圖(tu)分(fen)類號:TM411文獻標識碼:A 文章(zhang)編號:
Abstract: In power system, relay protection device is found in time and the fault alarm, an automatic protection device. Substation as the power distribution and use of transfer stations, the use of advanced technology and equipment to its function and efficiency is also essential. This article in view of the 220kV transformer substation operation and protection measures of related question to carry on the discussion analysis, proposed the corresponding treatment measures and preventive measures.
Key Words:Substation; 220kV transformer; Relay protection
1 引 言
眾(zhong)所周知,電(dian)(dian)力(li)系統(tong)中非常重(zhong)要(yao)的(de)一部分就是(shi)變(bian)(bian)壓(ya)器,變(bian)(bian)壓(ya)器能否正常工作(zuo)對電(dian)(dian)網是(shi)否能高效安全的(de)運(yun)行起著決定性的(de)作(zuo)用(yong)。電(dian)(dian)力(li)系統(tong)會因為變(bian)(bian)壓(ya)器發生故(gu)障而(er)遭受(shou)極大(da)損害,因此(ci),對變(bian)(bian)電(dian)(dian)站變(bian)(bian)壓(ya)器采取相應的(de)保護措施特別(bie)重(zhong)要(yao)。
做好變(bian)壓器(qi)的管理維護(hu)工(gong)作是我們工(gong)作的一部分(fen)內(nei)容,在加強(qiang)維護(hu)的前提下,還(huan)要做好對其運行狀況的記錄工(gong)作,從而(er)能夠及(ji)時發(fa)現問題并解決問題,使電力(li)系(xi)統的正常(chang)運轉得(de)到保障。為了及(ji)時發(fa)現并解決故障,變(bian)電站(zhan)配備(bei)了繼電保護(hu)裝置,保障了變(bian)壓器(qi)和變(bian)電站(zhan)甚至(zhi)整個(ge)電力(li)系(xi)統的正常(chang)運行。
本文針(zhen)對(dui)220kV變電站變壓器運(yun)行的相關(guan)內容作了概述(shu)(shu),簡要敘述(shu)(shu)了其(qi)操作要點,對(dui)繼電保護裝置使用條(tiao)件和(he)維(wei)護也做了相關(guan)闡述(shu)(shu),對(dui)相關(guan)工作人員(yuan)具有一定的指導意義。
2220kV變電站及繼電保護(hu)概述
2.1 220kV變(bian)電(dian)站變(bian)壓器運(yun)行概況
(1)工作原理
變(bian)(bian)(bian)電站的(de)主要設備就是(shi)(shi)變(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi),常用的(de)變(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)有(you)三種(zhong),分為(wei):自耦(ou)變(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)、三繞(rao)組(zu)(zu)(zu)變(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)和(he)雙繞(rao)組(zu)(zu)(zu)變(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)。自耦(ou)變(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)的(de)高低(di)壓(ya)(ya)(ya)(ya)(ya)每(mei)相共(gong)用一個(ge)繞(rao)組(zu)(zu)(zu),低(di)壓(ya)(ya)(ya)(ya)(ya)繞(rao)組(zu)(zu)(zu)的(de)出(chu)線(xian)是(shi)(shi)通過(guo)從高壓(ya)(ya)(ya)(ya)(ya)繞(rao)組(zu)(zu)(zu)中間抽出(chu)一個(ge)頭(tou)實現的(de),電壓(ya)(ya)(ya)(ya)(ya)高低(di)正比于繞(rao)組(zu)(zu)(zu)匝數,而電流則(ze)是(shi)(shi)同繞(rao)組(zu)(zu)(zu)匝數成反(fan)比。
以(yi)變壓(ya)(ya)器(qi)作用分(fen)類,變壓(ya)(ya)器(qi)可分(fen)為降壓(ya)(ya)變壓(ya)(ya)器(qi)和(he)升壓(ya)(ya)變壓(ya)(ya)器(qi)。前(qian)者主(zhu)要用于受端(duan)變電(dian)(dian)(dian)(dian)站,后(hou)者則主(zhu)要用于電(dian)(dian)(dian)(dian)力(li)系統送端(duan)變電(dian)(dian)(dian)(dian)站。為了在不(bu)同負荷情況下(xia)保持合格的(de)電(dian)(dian)(dian)(dian)壓(ya)(ya),必須是(shi)變壓(ya)(ya)器(qi)具有同電(dian)(dian)(dian)(dian)力(li)系統相適應的(de)電(dian)(dian)(dian)(dian)壓(ya)(ya)以(yi)及不(bu)定期的(de)將變壓(ya)(ya)器(qi)的(de)分(fen)接頭切(qie)換[1]。
電(dian)(dian)(dian)(dian)流(liu)互(hu)感(gan)器(qi)(qi)(qi)和(he)(he)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)互(hu)感(gan)器(qi)(qi)(qi)二(er)者的(de)工作原理同變(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)類(lei)似,其工作原理是(shi):將高(gao)壓(ya)(ya)(ya)(ya)、大(da)電(dian)(dian)(dian)(dian)流(liu)按一定比(bi)例變(bian)成低(di)壓(ya)(ya)(ya)(ya)、小電(dian)(dian)(dian)(dian)流(liu),即將高(gao)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)設(she)備以及母線的(de)運行(xing)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)、大(da)電(dian)(dian)(dian)(dian)流(liu)在(zai)此比(bi)例下變(bian)成由測(ce)量(liang)儀表(biao)及控制設(she)備能夠給(gei)出(chu)的(de)低(di)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)和(he)(he)小電(dian)(dian)(dian)(dian)流(liu)。設(she)備在(zai)正常情(qing)況下運行(xing)的(de)電(dian)(dian)(dian)(dian)流(liu)互(hu)感(gan)器(qi)(qi)(qi)的(de)二(er)次(ci)電(dian)(dian)(dian)(dian)流(liu)為5A或1A,電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)互(hu)感(gan)器(qi)(qi)(qi)的(de)二(er)次(ci)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)為100V,需要注意的(de)是(shi),由于負荷經(jing)常同電(dian)(dian)(dian)(dian)流(liu)互(hu)感(gan)器(qi)(qi)(qi)的(de)二(er)次(ci)繞組相連接形成短路,因此,需要加大(da)對這種問(wen)題的(de)注意,從(cong)而(er)避(bi)免設(she)備和(he)(he)人身(shen)安(an)全受到(dao)損害。
(2)變壓器(qi)非正常(chang)運行(xing)的情況(kuang)
變(bian)壓器會(hui)因為(wei)出現外部短(duan)路或者(zhe)過(guo)負荷等情況(kuang)發生過(guo)電流(liu)、油面降低(di)和(he)溫度升高等非正常現象(xiang)。對此,變(bian)壓器會(hui)根據不(bu)同的情況(kuang)安裝不(bu)同的保護(hu)裝置,主要(yao)由(you)以下幾種:
1電(dian)流速斷保護(hu)(hu)和差(cha)動(dong)保護(hu)(hu),保護(hu)(hu)方式是(shi)(shi)瞬時作用于信號跳閘,適用異常情況是(shi)(shi)變壓器的內部故障(zhang)或引(yin)出線間的短路、接地短路。
2氣(qi)體(ti)保(bao)護(hu),這(zhe)種保(bao)護(hu)形式的(de)保(bao)護(hu)機理(li)同上,其適用的(de)異常情況是變壓器(qi)的(de)油箱油面降(jiang)低或(huo)者發生了(le)內部故障。
4過負荷(he)保(bao)護(hu),這種保(bao)護(hu)形(xing)式是(shi)通過變壓(ya)器(qi)的(de)(de)信號系統(tong)發(fa)生作(zuo)用的(de)(de),適(shi)用的(de)(de)異常(chang)情況是(shi)過電流的(de)(de)產生。
5過流(liu)繼電保護,當1,2方式的(de)保護沒有達(da)到(dao)預(yu)期的(de)效果時(shi),這種(zhong)方式作為后備保護,其適用的(de)異(yi)常情況(kuang)與前兩者類似。
2.2 繼電保護概述
對(dui)電(dian)力系(xi)統(tong)(tong)故(gu)障(zhang)、危及安全運行(xing)的(de)(de)異常工(gong)(gong)況以(yi)(yi)及其對(dui)策的(de)(de)反(fan)事故(gu)自動(dong)化措(cuo)施的(de)(de)研究和(he)探討是繼(ji)電(dian)保護的(de)(de)措(cuo)施的(de)(de)主(zhu)要目的(de)(de)。在(zai)電(dian)力系(xi)統(tong)(tong)發(fa)生故(gu)障(zhang)或異常工(gong)(gong)況時(shi),在(zai)最(zui)短時(shi)間(jian)內對(dui)故(gu)障(zhang)進行(xing)分(fen)析,給(gei)出故(gu)障(zhang)發(fa)生的(de)(de)原(yuan)因(yin)以(yi)(yi)及自動(dong)切除發(fa)生故(gu)障(zhang)的(de)(de)電(dian)力系(xi)統(tong)(tong)的(de)(de)一部(bu)分(fen),是電(dian)力系(xi)統(tong)(tong)繼(ji)電(dian)保護的(de)(de)基本任務。
繼(ji)電(dian)(dian)(dian)保(bao)護(hu)(hu)裝(zhuang)置的發(fa)(fa)展趕不上電(dian)(dian)(dian)力(li)(li)行(xing)業發(fa)(fa)展的腳步,因此(ci),經常會造成全(quan)電(dian)(dian)(dian)力(li)(li)系(xi)(xi)統(tong)長(chang)期(qi)大(da)面(mian)積停電(dian)(dian)(dian)的嚴重事故(gu)(gu)的發(fa)(fa)生。所以,對繼(ji)電(dian)(dian)(dian)保(bao)護(hu)(hu)的發(fa)(fa)展要(yao)從電(dian)(dian)(dian)力(li)(li)系(xi)(xi)統(tong)全(quan)局出發(fa)(fa),僅僅切除系(xi)(xi)統(tong)中發(fa)(fa)生故(gu)(gu)障(zhang)的一(yi)部分是遠(yuan)遠(yuan)不夠的,還要(yao)多切除后的系(xi)(xi)統(tong)運行(xing)可能(neng)出現的工況(kuang)進行(xing)分析,比如系(xi)(xi)統(tong)是否會出現一(yi)定(ding)的不穩定(ding)特征等(deng),系(xi)(xi)統(tong)保(bao)護(hu)(hu)就是為了在大(da)電(dian)(dian)(dian)力(li)(li)系(xi)(xi)統(tong)正(zheng)常運行(xing)被破壞(huai)時,將影響(xiang)范圍限制到最(zui)小(xiao),盡(jin)可能(neng)地減少經濟(ji)損失。
3 220kV變(bian)(bian)電站變(bian)(bian)壓器(qi)的(de)正常操作(zuo)
3.1 操作規定
(1)220 kV變壓器停送電(dian)操作時(shi),變壓器中性(xing)點必須直接接地(di)。
(2)變壓器(qi)送電操(cao)作時,應由(you)裝有保(bao)護裝置的(de)(de)電源(yuan)側充(chong)電。斷開時,裝有保(bao)護裝置的(de)(de)電源(yuan)側后斷。
(3)變(bian)壓器送電時(shi),應(ying)先(xian)將變(bian)壓器冷卻系(xi)統相應(ying)投入。
(4)變壓器送電前(qian),將變壓器有載(zai)分接開關電源送電。
(5)大修后的變壓(ya)器,投(tou)入前必須測定相位;不允(yun)許用(yong)閘(zha)刀拉合(he)空載電流超過2 A的空載變壓(ya)器。
(6)變(bian)壓器改變(bian)分接頭(tou)的操作,對(dui)于(yu)無載調(diao)(diao)壓的變(bian)壓器,應在停電后進行(xing)操作。如三相電阻差(cha)大,應設法查明原因,并匯報上級領導決定(ding)是否(fou)投(tou)入運行(xing)。分接頭(tou)調(diao)(diao)整后應有(you)詳細的記錄。裝(zhuang)有(you)有(you)載調(diao)(diao)壓裝(zhuang)置(zhi)的變(bian)壓器,可以(yi)在運行(xing)中調(diao)(diao)整分接頭(tou),但必須遵守制(zhi)造廠(chang)的有(you)關規定(ding)及注(zhu)意事項。
(7)變壓器安(an)裝、檢修后或(huo)投(tou)入運(yun)(yun)行前以及停運(yun)(yun)半個月以上(shang)者,均應測(ce)(ce)(ce)定線圈的絕緣(yuan)電阻,測(ce)(ce)(ce)得數值(zhi)和測(ce)(ce)(ce)量時(shi)的油溫記入變壓器記錄本內[2]。
3.2 運行檢查
變壓(ya)器(qi)投(tou)入前的檢(jian)查(cha):1)檢(jian)查(cha)工作票全部(bu)結束,所有安全措(cuo)施已拆除(chu),常(chang)設遮攔已
恢復,檢修(xiu)工作現場清(qing)潔(jie)干凈(jing),變(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)設備上無遺物。2)測定(ding)絕緣電阻合格,檢修(xiu)班組在(zai)檢修(xiu)記錄(lu)本上進行(xing)詳細(xi)記錄(lu),并(bing)(bing)有(you)可以(yi)將變(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)投(tou)入(ru)運行(xing)的書面交待,有(you)關工作負責人應(ying)簽名。3)變(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)一次(ci)系(xi)統接(jie)線完好(hao)(hao)(hao)(hao),變(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)外殼、中(zhong)性點引(yin)線接(jie)地(di)良好(hao)(hao)(hao)(hao),并(bing)(bing)安(an)裝(zhuang)牢固,避雷線及接(jie)地(di)線接(jie)地(di)良好(hao)(hao)(hao)(hao)。4)變(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)油枕及充油套管(guan)的油色透明,油位正(zheng)(zheng)常(chang),無漏油現象。5)變(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)本體、套管(guan)、引(yin)出(chu)線絕緣子清(qing)潔(jie)無裂紋(wen)、損壞(huai)現象。變(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)分接(jie)頭位置(zhi)正(zheng)(zheng)確(que),有(you)載調壓(ya)(ya)(ya)(ya)(ya)(ya)裝(zhuang)置(zhi)應(ying)正(zheng)(zheng)常(chang)。6)變(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)油再生裝(zhuang)置(zhi)、換熱器(qi)、呼吸器(qi)、瓦(wa)斯(si)繼(ji)電器(qi)投(tou)入(ru)正(zheng)(zheng)常(chang),瓦(wa)斯(si)繼(ji)電器(qi)內(nei)應(ying)充滿(man)油,無氣體,連接(jie)管(guan)的閥門應(ying)打開。安(an)全釋(shi)放壓(ya)(ya)(ya)(ya)(ya)(ya)力(li)閥完好(hao)(hao)(hao)(hao),呼吸器(qi)內(nei)干燥劑呈(cheng)藍色(失效(xiao)時(shi)呈(cheng)紅色)。7)變(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)溫(wen)度(du)指(zhi)示器(qi)指(zhi)示正(zheng)(zheng)確(que),并(bing)(bing)完好(hao)(hao)(hao)(hao),無破損現象。8)檢查變(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)冷(leng)卻(que)系(xi)統具備啟動(dong)(dong)(dong)條件,控制柜內(nei)接(jie)線正(zheng)(zheng)確(que),冷(leng)卻(que)系(xi)統試(shi)運正(zheng)(zheng)常(chang)。9)檢查繼(ji)電保(bao)護及自動(dong)(dong)(dong)裝(zhuang)置(zhi)投(tou)入(ru)正(zheng)(zheng)確(que),保(bao)護壓(ya)(ya)(ya)(ya)(ya)(ya)板在(zai)相應(ying)位置(zhi),符合《繼(ji)電保(bao)護及自動(dong)(dong)(dong)裝(zhuang)置(zhi)運行(xing)規(gui)程(cheng)》和有(you)關規(gui)定(ding)。10)檢查變(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)開關、隔離開關機構良好(hao)(hao)(hao)(hao);SF6壓(ya)(ya)(ya)(ya)(ya)(ya)力(li)正(zheng)(zheng)常(chang);電壓(ya)(ya)(ya)(ya)(ya)(ya)互感器(qi)、電流(liu)互感器(qi)及有(you)關表計(ji)回路完好(hao)(hao)(hao)(hao);二次(ci)接(jie)線端子無松動(dong)(dong)(dong)現象。11)檢查變(bian)(bian)壓(ya)(ya)(ya)(ya)(ya)(ya)器(qi)消防系(xi)統回路正(zheng)(zheng)常(chang)[3]。
變壓器運行中的檢查:1)變壓器的聲(sheng)音正常;2)油(you)枕充油(you)套管(guan)油(you)壓正常,油(you)位、油(you)
色正(zheng)常;3)油溫(wen)(wen)正(zheng)常;4)變(bian)壓(ya)(ya)器(qi)(qi)各部應無(wu)漏油、滲油現(xian)(xian)象;5)套管外部應清潔(jie),無(wu)破損(sun)、無(wu)裂紋現(xian)(xian)象,無(wu)放電(dian)痕跡;6)瓦斯繼(ji)電(dian)器(qi)(qi)內(nei),油枕(zhen)集氣盒內(nei)應無(wu)氣體;7)引(yin)線接頭、電(dian)纜(lan)、母線應無(wu)發熱(re)現(xian)(xian)象;8)呼(hu)吸器(qi)(qi)內(nei)干(gan)燥劑是(shi)否(fou)(fou)變(bian)化,呼(hu)吸是(shi)否(fou)(fou)暢通;9)冷(leng)卻裝(zhuang)置(zhi)正(zheng)常;10)外殼(ke)接地線接地良好;11)消防(fang)裝(zhuang)置(zhi)工(gong)(gong)作正(zheng)常;12)調壓(ya)(ya)裝(zhuang)置(zhi)工(gong)(gong)作正(zheng)常;13)室內(nei)變(bian)壓(ya)(ya)器(qi)(qi)應檢查門(men)窗(chuang)、照明(ming)是(shi)否(fou)(fou)完好,有(you)無(wu)漏水,空氣溫(wen)(wen)度是(shi)否(fou)(fou)適(shi)宜;14)干(gan)式變(bian)壓(ya)(ya)器(qi)(qi)的(de)通風道(dao)有(you)無(wu)阻塞,緊固(gu)件有(you)無(wu)松動,有(you)無(wu)局部過熱(re)現(xian)(xian)象。
4 繼(ji)電保護裝置使用條件和維護
繼(ji)電(dian)(dian)保(bao)(bao)護裝置(zhi)(zhi)是實現繼(ji)電(dian)(dian)保(bao)(bao)護的(de)(de)(de)基本條件,要實現繼(ji)電(dian)(dian)保(bao)(bao)護的(de)(de)(de)作用,就(jiu)必(bi)須(xu)要具(ju)備(bei)(bei)有科學(xue)先(xian)進、行之有效(xiao)的(de)(de)(de)繼(ji)電(dian)(dian)保(bao)(bao)護裝置(zhi)(zhi),所謂“工欲善(shan)其(qi)事,必(bi)先(xian)利其(qi)器”,有了設備(bei)(bei)的(de)(de)(de)支持,才真正具(ju)備(bei)(bei)了維(wei)護電(dian)(dian)力系(xi)統(tong)的(de)(de)(de)能(neng)力。因此,要做好(hao)繼(ji)電(dian)(dian)保(bao)(bao)護的(de)(de)(de)工作,就(jiu)必(bi)須(xu)要重視(shi)保(bao)(bao)護的(de)(de)(de)設備(bei)(bei)。而設備(bei)(bei)的(de)(de)(de)質量問題,直(zhi)接(jie)決(jue)定了繼(ji)電(dian)(dian)保(bao)(bao)護的(de)(de)(de)效(xiao)果,因而必(bi)須(xu)對繼(ji)電(dian)(dian)保(bao)(bao)護的(de)(de)(de)裝置(zhi)(zhi)提(ti)出較高的(de)(de)(de)要求。
繼(ji)電(dian)保護裝置(zhi)的(de)重要(yao)(yao)性,不僅要(yao)(yao)在選(xuan)用上(shang)考慮其是(shi)否達到(dao)基本(ben)運行(xing)條件(jian)的(de)要(yao)(yao)求,還要(yao)(yao)在日(ri)常的(de)檢(jian)測(ce)和(he)維護上(shang)做好工(gong)作。
首先,要(yao)全面了解設(she)備(bei)(bei)的(de)(de)初始(shi)狀態。繼(ji)電保護設(she)備(bei)(bei)的(de)(de)初始(shi)狀態,影響(xiang)其(qi)日后的(de)(de)正常和有(you)效運行。因此必(bi)須(xu)注意(yi)收集整理設(she)備(bei)(bei)圖紙、技術資料以(yi)及相關設(she)備(bei)(bei)的(de)(de)運行和檢(jian)測數據的(de)(de)資料。對設(she)備(bei)(bei)日常狀態的(de)(de)檢(jian)修,要(yao)對設(she)備(bei)(bei)生命周期中各個(ge)環節(jie)都必(bi)須(xu)予以(yi)關注,進行全過程的(de)(de)管(guan)理。
其(qi)次(ci),要(yao)對設(she)(she)(she)備(bei)(bei)(bei)運(yun)行(xing)(xing)狀(zhuang)(zhuang)態數(shu)據進(jin)(jin)行(xing)(xing)及時(shi)(shi)全(quan)面(mian)的(de)(de)(de)統計(ji)分(fen)析(xi)。首(shou)先(xian)要(yao)了解設(she)(she)(she)備(bei)(bei)(bei)出現(xian)故障(zhang)的(de)(de)(de)特(te)點和規律,進(jin)(jin)而通過對繼(ji)電保(bao)護裝(zhuang)置運(yun)行(xing)(xing)狀(zhuang)(zhuang)態的(de)(de)(de)日(ri)常數(shu)據的(de)(de)(de)分(fen)析(xi),預(yu)先(xian)判斷分(fen)析(xi)故障(zhang)出現(xian)的(de)(de)(de)部(bu)分(fen)和時(shi)(shi)間,在故障(zhang)未發生(sheng)時(shi)(shi),及時(shi)(shi)的(de)(de)(de)排查。因(yin)此狀(zhuang)(zhuang)態檢(jian)(jian)修數(shu)據管理(li)就顯得(de)非常重要(yao),要(yao)把設(she)(she)(she)備(bei)(bei)(bei)運(yun)行(xing)(xing)的(de)(de)(de)記(ji)錄、設(she)(she)(she)備(bei)(bei)(bei)狀(zhuang)(zhuang)態監測與診斷的(de)(de)(de)數(shu)據等結合起來,通過正確(que)的(de)(de)(de)完整的(de)(de)(de)技術數(shu)據進(jin)(jin)行(xing)(xing)狀(zhuang)(zhuang)態檢(jian)(jian)修。
再次,要了解繼(ji)電(dian)設備技(ji)(ji)術發展趨勢,采(cai)用新的技(ji)(ji)術對設備進行監管和維護。必須加強(qiang)對新技(ji)(ji)術的應(ying)用,唯此才能保證(zheng)保護裝置(zhi)的科學有效,在電(dian)力系統的保護中發揮應(ying)有的貢獻。5結束語
變壓(ya)器的(de)正常運(yun)行(xing)對(dui)電網的(de)安(an)全、可靠輸(shu)電起著(zhu)重要作用。應(ying)加強變壓(ya)器的(de)運(yun)行(xing)管(guan)理,做好(hao)變壓(ya)器的(de)運(yun)行(xing)維護(hu),根據變壓(ya)器運(yun)行(xing)中的(de)現象發現隱(yin)患(huan),及時(shi)排除,保障變壓(ya)器的(de)安(an)全運(yun)行(xing)。
參考文獻
[1] 馬志(zhi)學.變(bian)壓器油(you)中溶解(jie)氣(qi)體(ti)分析使用的判(pan)斷方法[J].科技信息(xi),2007(7):76.
[2] 馮志敏,黃貴海.一起(qi)變壓(ya)器(qi)故障分(fen)析(xi)與判斷的實例(li)[J].電(dian)力學報,2006(21):117~118.
篇8
關鍵詞:變壓器;故障;診(zhen)斷;檢修
中(zhong)圖分(fen)類(lei)號:TM4 文(wen)獻標志碼:A 文(wen)章編號:1000-8772(2013)09-0174-02
變(bian)(bian)(bian)壓(ya)器(qi)是(shi)(shi)變(bian)(bian)(bian)電(dian)(dian)所(suo)中(zhong)關(guan)鍵的(de)(de)一次設備,其(qi)主要功能(neng)(neng)是(shi)(shi)升(sheng)高或降低電(dian)(dian)壓(ya),以利于電(dian)(dian)能(neng)(neng)的(de)(de)合(he)理輸送,分(fen)配和使(shi)用(yong),在不(bu)同的(de)(de)負荷(he)和環境下(xia)用(yong)的(de)(de)變(bian)(bian)(bian)壓(ya)器(qi)是(shi)(shi)不(bu)同的(de)(de),應(ying)該選擇(ze)恰當(dang)的(de)(de)設備才能(neng)(neng)保證(zheng)在運行(xing)(xing)中(zhong),即能(neng)(neng)有助(zhu)于降低電(dian)(dian)能(neng)(neng)損耗,還能(neng)(neng)減免供(gong)電(dian)(dian)故障帶來的(de)(de)經濟損失,變(bian)(bian)(bian)壓(ya)器(qi)在電(dian)(dian)力系統中(zhong)起著變(bian)(bian)(bian)壓(ya)作用(yong)、但隨著近幾年變(bian)(bian)(bian)壓(ya)器(qi)的(de)(de)改造(zao)、變(bian)(bian)(bian)電(dian)(dian)設備由(you)定期檢(jian)修(xiu)制(zhi)向狀態檢(jian)修(xiu)制(zhi)的(de)(de)逐(zhu)步過渡,主設備的(de)(de)大(da)修(xiu)周期在逐(zhu)漸(jian)延長(chang),因而運行(xing)(xing)中(zhong)的(de)(de)戶外式戶外變(bian)(bian)(bian)壓(ya)器(qi)出現(xian)的(de)(de)問題大(da)幅上升(sheng),直接影響(xiang)系統的(de)(de)供(gong)電(dian)(dian)可靠(kao)性和安全性。本文就變(bian)(bian)(bian)壓(ya)器(qi)的(de)(de)一些(xie)故障問題進行(xing)(xing)了分(fen)析,并結合(he)問題提出解決辦(ban)法。
一(yi)、變壓器的(de)簡(jian)介與結(jie)構
(一)變壓器的(de)簡介
1 鐵心
鐵(tie)(tie)(tie)心(xin)是變壓器中(zhong)主要的磁路(lu)部分(fen)(fen)。通常由含硅量較高,厚度為(wei)0.35或(huo)0.5mm,表面涂有絕緣(yuan)漆的熱軋(ya)或(huo)冷軋(ya)硅鋼片疊裝(zhuang)而(er)成鐵(tie)(tie)(tie)心(xin)分(fen)(fen)為(wei)鐵(tie)(tie)(tie)心(xin)柱和(he)鐵(tie)(tie)(tie)軛(e)倆部分(fen)(fen),鐵(tie)(tie)(tie)心(xin)柱套有繞組(zu);鐵(tie)(tie)(tie)軛(e)閉合磁路(lu)之用鐵(tie)(tie)(tie)心(xin)結構的基本形式(shi)有心(xin)式(shi)和(he)殼式(shi)兩(liang)種。
2 繞組
繞組是變壓器的電(dian)路部(bu)分,它是用紙包的絕緣扁線(xian)或圓線(xian)繞成,變壓器的基本原理是電(dian)磁感應原理。
(二)變壓器的結構
變壓(ya)器(qi)(qi)(qi)(qi)主要部(bu)件是繞組和鐵心(xin)(器(qi)(qi)(qi)(qi)身),繞組是變壓(ya)器(qi)(qi)(qi)(qi)的(de)(de)電路(lu),鐵心(xin)是變壓(ya)器(qi)(qi)(qi)(qi)的(de)(de)磁路(lu)。二(er)者構成變壓(ya)器(qi)(qi)(qi)(qi)的(de)(de)核心(xin)即(ji)電磁部(bu)分除了電磁部(bu)分,還(huan)有油(you)箱/冷(leng)卻裝(zhuang)置/絕緣套管(guan)/調壓(ya)和保護裝(zhuang)置等部(bu)件。
1 鐵心
(1)型式:心式(結構簡單工藝簡單應用(yong)廣泛)/殼(ke)式(用(yong)在小(xiao)容量(liang)變壓器和電爐變壓器)。
(2)材料:一般由(you)0.35mm/0.5ram冷軋(也用熱軋)硅鋼片疊成。
(3)鐵(tie)心交疊:相(xiang)鄰層按不同方式(shi)交錯疊放(fang),將接(jie)縫錯開。偶數層剛(gang)好壓(ya)著(zhu)奇(qi)數層的接(jie)縫,從而減(jian)少了磁阻(zu),便于磁通(tong)流通(tong)。
(4)鐵心柱截面形狀:小(xiao)型變壓器(qi)做(zuo)成方(fang)形或者矩形;大型變壓器(qi)做(zuo)成階梯形。容量大則級數多。疊片間留有(you)間隙作為(wei)油道(縱向/橫向)。
2 繞組
一般用絕(jue)緣(yuan)扁銅(tong)線或圓銅(tong)線在(zai)繞(rao)線模上(shang)(shang)繞(rao)制(zhi)而成(cheng)。繞(rao)組套(tao)裝(zhuang)在(zai)變壓器(qi)(qi)鐵心(xin)柱(zhu)上(shang)(shang),低壓繞(rao)組在(zai)內層,高壓繞(rao)組套(tao)裝(zhuang)在(zai)低壓繞(rao)組外(wai)層,以便于(yu)絕(jue)緣(yuan)。油(you)(you)/油(you)(you)箱(xiang)/冷卻/安全裝(zhuang)置器(qi)(qi)身裝(zhuang)在(zai)油(you)(you)箱(xiang)內,油(you)(you)箱(xiang)內充滿變壓器(qi)(qi)油(you)(you)變壓器(qi)(qi)油(you)(you)是(shi)一種礦物油(you)(you),具有很好的絕(jue)緣(yuan)性能。
變(bian)壓器油(you)起兩個(ge)作(zuo)用:
(1)在變壓器繞組與(yu)繞組、繞組與(yu)鐵心(xin)及油箱之間(jian)起絕緣作用。
(2)變(bian)壓器(qi)油受熱(re)后產(chan)生對流,對變(bian)壓器(qi)鐵心和繞(rao)組(zu)起散熱(re)作用(yong)。
油(you)(you)箱(xiang)有許多散熱油(you)(you)管(guan),以增大(da)散熱面積。為了加(jia)快散熱,有的大(da)型(xing)變壓器(qi)采用內部油(you)(you)泵(beng)強迫油(you)(you)循環,外部用變壓器(qi)風扇吹風或用自來水沖淋變壓器(qi)油(you)(you)箱(xiang),這(zhe)些都是變壓器(qi)的冷卻裝置。
1油箱/2儲(chu)油柜(ju)/3氣(qi)(qi)體繼電器/4為安全氣(qi)(qi)道。
變壓器(qi)(qi)運行時(shi)產(chan)生熱量,使變壓器(qi)(qi)油膨脹,并(bing)流進(jin)儲油柜中。
儲油柜使變壓器油與空(kong)氣接(jie)觸面變小,減(jian)(jian)緩了變壓器油的氧(yang)化和吸收空(kong)氣水(shui)分的速度(du)。從而減(jian)(jian)緩了油的變質(zhi)。
故障時,熱量會使變(bian)壓(ya)器(qi)油(you)(you)汽(qi)化,觸(chu)動(dong)氣體繼(ji)電器(qi)發出報(bao)警信號(hao)或切斷電源。如(ru)果是嚴重事(shi)故,變(bian)壓(ya)器(qi)油(you)(you)大量汽(qi)化,油(you)(you)氣沖(chong)破(po)安全(quan)氣道(dao)管口的(de)密封玻璃,沖(chong)出變(bian)壓(ya)器(qi)油(you)(you)箱,避免(mian)油(you)(you)箱爆裂。
二、變壓(ya)器的工(gong)作原理和分類
(一(yi))變壓器的(de)工作原理
變壓(ya)器的(de)工(gong)作原理是(shi)用電(dian)磁感(gan)應原理工(gong)作的(de)。變壓(ya)器有(you)兩(liang)組(zu)線圈(quan)(quan)。一次(ci)(ci)線圈(quan)(quan)和二次(ci)(ci)線圈(quan)(quan)。次(ci)(ci)級(ji)(ji)線圈(quan)(quan)在初級(ji)(ji)線圈(quan)(quan)外邊。當(dang)初級(ji)(ji)線圈(quan)(quan)通(tong)上交流電(dian)時,變壓(ya)器鐵(tie)芯(xin)產生(sheng)交變磁場,次(ci)(ci)級(ji)(ji)線圈(quan)(quan)就(jiu)產生(sheng)感(gan)應電(dian)動(dong)勢。變壓(ya)器的(de)線圈(quan)(quan)的(de)匝數比(bi)(bi)等于電(dian)壓(ya)比(bi)(bi)。例如:初級(ji)(ji)線圈(quan)(quan)是(shi)500匝,次(ci)(ci)級(ji)(ji)線圈(quan)(quan)是(shi)250匝,初級(ji)(ji)通(tong)上220V交流電(dian),次(ci)(ci)級(ji)(ji)電(dian)壓(ya)就(jiu)是(shi)1 IOV。變壓(ya)器能降壓(ya)也能升(sheng)壓(ya)。
(二(er))變壓器(qi)的分類(lei)
1 變壓器(qi)按用(yong)途(tu)分類
(1)電(dian)力(li)變壓器:用于(yu)輸配電(dian)系(xi)統(tong)的升、降電(dian)壓。
(2)儀用(yong)變壓器:如電(dian)壓互感(gan)器、電(dian)流互感(gan)器、用(yong)于測量儀表(biao)和繼電(dian)保護(hu)裝置。
(3)試(shi)驗變壓器:能產(chan)生高壓,對(dui)電氣(qi)設(she)備進(jin)行高壓試(shi)驗。
(4)特種(zhong)變壓器:如電爐變壓器、整流變壓器、調整變壓器等。
2 按相數分類
(1)單相變壓(ya)器:用于單相負荷和三相變壓(ya)器組。
(2)三(san)相變壓(ya)器:用于三(san)相系統的升、降電壓(ya)。
3 按冷卻分類
(1)干式變(bian)壓器(qi):依靠空氣對(dui)流進行冷卻,一般用于局部照明、電(dian)子線路等小容量變(bian)壓器(qi)。
(2)油(you)(you)浸(jin)式變(bian)壓器:依靠油(you)(you)作(zuo)冷卻介質、如油(you)(you)浸(jin)自冷、油(you)(you)浸(jin)風冷、油(you)(you)浸(jin)水(shui)冷、強迫油(you)(you)循(xun)環等。
4 按鐵芯形式分類
(1)芯式變壓(ya)器(qi):用于(yu)高壓(ya)的(de)電力變壓(ya)器(qi)。
(2)殼式變(bian)(bian)壓(ya)器(qi)(qi)(qi):用(yong)于大電流的特(te)殊變(bian)(bian)壓(ya)器(qi)(qi)(qi),如電爐變(bian)(bian)壓(ya)器(qi)(qi)(qi)、電焊變(bian)(bian)壓(ya)器(qi)(qi)(qi);或用(yong)于電子儀器(qi)(qi)(qi)及電視、收音機等的電源變(bian)(bian)壓(ya)器(qi)(qi)(qi)。
5 按繞組(zu)形(xing)式(shi)分類(lei)
(1)雙(shuang)繞(rao)組變(bian)壓器(qi):用于連接(jie)電力系統(tong)中的兩個電壓等級。
(2)三繞組(zu)變(bian)壓器:一般用于(yu)電力系統區(qu)域(yu)變(bian)電站中,連接三個電壓等(deng)級。
(3)自耦變電器:用(yong)于連接(jie)不同電壓的電力(li)系統。也可做為(wei)普(pu)通的升壓或降(jiang)后變壓器用(yong)。
三、常見(jian)故障及其診(zhen)斷措施
(一)變壓器滲油
變(bian)(bian)壓器滲漏油不(bu)(bu)僅會給(gei)電力企業帶來(lai)較大(da)的經(jing)濟損(sun)失、環境污染,還會影響變(bian)(bian)壓器的安全運行,可能(neng)造(zao)成不(bu)(bu)必(bi)要(yao)的停運甚至變(bian)(bian)壓器的損(sun)毀事故,給(gei)電力客戶帶來(lai)生(sheng)產上的損(sun)失和生(sheng)活上的不(bu)(bu)便。因(yin)此,有必(bi)要(yao)解決變(bian)(bian)壓器滲漏油問題(ti)。
油(you)箱焊(han)縫(feng)滲油(you)。對于平(ping)面接(jie)(jie)縫(feng)處(chu)(chu)滲油(you)可直接(jie)(jie)進(jin)行焊(han)接(jie)(jie),對于拐角及加(jia)強筋連接(jie)(jie)處(chu)(chu)滲油(you)則往往滲漏(lou)點(dian)查找不準,或補焊(han)后由于內應力的原因再次滲漏(lou)。對于這樣的滲點(dian)可加(jia)用(yong)鐵(tie)板進(jin)行補焊(han),兩面連接(jie)(jie)處(chu)(chu),可將鐵(tie)板裁成紡錘(chui)狀進(jin)行補焊(han);三面連接(jie)(jie)處(chu)(chu)可根(gen)據實(shi)際位置將鐵(tie)板裁成三角形(xing)進(jin)行補焊(han);該法也適用(yong)于套管電流互(hu)感(gan)器二次引線(xian)盒拐角焊(han)縫(feng)滲漏(lou)焊(han)接(jie)(jie)。
高(gao)壓套(tao)管(guan)升(sheng)高(gao)座或進入孔(kong)法(fa)蘭(lan)(lan)滲油(you)。這(zhe)些部位(wei)主要是由于(yu)膠(jiao)(jiao)墊安裝(zhuang)不合適(shi),運行中可對(dui)法(fa)蘭(lan)(lan)進行施(shi)膠(jiao)(jiao)密(mi)封。封堵(du)前(qian)用堵(du)漏(lou)膠(jiao)(jiao)將(jiang)(jiang)法(fa)蘭(lan)(lan)之間(jian)縫隙堵(du)好,待(dai)堵(du)漏(lou)膠(jiao)(jiao)完全固化后(hou),退出(chu)一個法(fa)蘭(lan)(lan)緊(jin)固螺(luo)絲(si),將(jiang)(jiang)施(shi)膠(jiao)(jiao)槍(qiang)嘴擰(ning)人(ren)該螺(luo)絲(si)孔(kong),然后(hou)用高(gao)壓將(jiang)(jiang)密(mi)封膠(jiao)(jiao)注(zhu)入法(fa)蘭(lan)(lan)間(jian)隙,直(zhi)至各法(fa)蘭(lan)(lan)螺(luo)絲(si)帽有(you)膠(jiao)(jiao)擠出(chu)為(wei)止。
低壓(ya)(ya)側(ce)套管滲漏。其原因是受母(mu)(mu)線(xian)(xian)(xian)拉伸(shen)(shen)和(he)低壓(ya)(ya)側(ce)引線(xian)(xian)(xian)引出(chu)偏(pian)短,膠珠壓(ya)(ya)在螺紋上。受母(mu)(mu)線(xian)(xian)(xian)拉伸(shen)(shen)時,可(ke)按規定對母(mu)(mu)線(xian)(xian)(xian)用伸(shen)(shen)縮(suo)節連(lian)接;如引線(xian)(xian)(xian)偏(pian)短,可(ke)重新調整引線(xian)(xian)(xian)引出(chu)長度:對調整引線(xian)(xian)(xian)有困(kun)難的(de),可(ke)在安裝膠珠的(de)各密封面加密封膠;為(wei)增大(da)壓(ya)(ya)緊力可(ke)將瓷質(zhi)壓(ya)(ya)帽換成(cheng)銅質(zhi)壓(ya)(ya)帽。
防(fang)爆管(guan)滲油。防(fang)爆管(guan)是(shi)變(bian)壓(ya)器(qi)內(nei)部發生故障導致變(bian)壓(ya)器(qi)內(nei)部壓(ya)力過大(da),避免變(bian)壓(ya)器(qi)油箱(xiang)(xiang)破(po)裂的(de)安(an)全措(cuo)施。但(dan)防(fang)爆管(guan)的(de)玻(bo)(bo)璃膜(mo)在變(bian)壓(ya)器(qi)運行中由于振動容易破(po)裂,又無法及時更換玻(bo)(bo)璃,潮氣因此進入油箱(xiang)(xiang),使絕(jue)緣油受潮,絕(jue)緣水平降低,危(wei)及設(she)備的(de)安(an)全。為此,把防(fang)爆管(guan)拆除,改裝壓(ya)力釋放閥即可。
(二)鐵心多點接地
變壓器(qi)鐵(tie)心有(you)且(qie)只(zhi)能有(you)一點(dian)(dian)接地(di)(di),出現(xian)兩點(dian)(dian)及以上的(de)接地(di)(di),為多點(dian)(dian)接地(di)(di)。變壓器(qi)鐵(tie)心多點(dian)(dian)接地(di)(di)運行將導(dao)致鐵(tie)心出現(xian)故障,危及變壓器(qi)的(de)安全運行,應及時進行處理。
直流電(dian)流沖擊(ji)法。拆除變壓器鐵心(xin)接地線,在變壓器鐵心(xin)與油箱之間加直流電(dian)壓進行短時大電(dian)流沖擊(ji),沖擊(ji)3-5次,常能燒掉(diao)鐵心(xin)的多余接地點(dian)(dian),起到很好的消除鐵心(xin)多點(dian)(dian)接地的效果。
開箱檢查。對安裝(zhuang)后未將箱蓋上定位(wei)銷(xiao)翻轉(zhuan)或除去造成多點接地(di)的(de),應將定位(wei)銷(xiao)翻轉(zhuan)過來或除掉。
夾件墊腳與鐵(tie)軛間的絕緣(yuan)紙板(ban)脫落或破(po)損者,應(ying)按絕緣(yuan)規范要求,更換一(yi)定厚(hou)度的新紙板(ban)。
因夾件肢(zhi)板距鐵心太近,使翹起的疊片與其(qi)相碰,則應調整夾件肢(zhi)板和扳直翹起的疊片,使兩者間距離符合絕緣間隙標(biao)準。
清除油(you)中的金屬異物、金屬顆粒及雜質(zhi),清除油(you)箱各部(bu)的油(you)泥,有條件則對(dui)變(bian)壓器(qi)油(you)進行真空干燥處理(li),清除水分。
(三)接頭過熱
載流接(jie)頭(tou)是變(bian)壓器本(ben)身及(ji)其聯系電(dian)網(wang)的(de)重要(yao)組成部(bu)分(fen)。接(jie)頭(tou)連(lian)接(jie)不好,將引起發熱甚至(zhi)燒(shao)斷,嚴重影響變(bian)壓器的(de)正常運行和電(dian)網(wang)的(de)安(an)全供電(dian)。因此,接(jie)頭(tou)過熱問題一定要(yao)及(ji)時解決。
銅(tong)(tong)(tong)鋁(lv)連(lian)接(jie)。變壓(ya)器的引出端頭(tou)都是(shi)銅(tong)(tong)(tong)制的,在屋外和潮(chao)濕的場所(suo)中(zhong),不能(neng)將(jiang)鋁(lv)導體用螺栓(shuan)與(yu)銅(tong)(tong)(tong)端頭(tou)連(lian)接(jie)。當銅(tong)(tong)(tong)與(yu)鋁(lv)的接(jie)觸(chu)(chu)面(mian)間滲入含有溶解(jie)鹽的水分,即電(dian)解(jie)液時(shi),在電(dian)耦(ou)的作用下,會(hui)產生(sheng)電(dian)解(jie)反應,鋁(lv)被強烈電(dian)腐蝕。結果,觸(chu)(chu)頭(tou)很快(kuai)遭到破壞,以致(zhi)發熱(re)甚至可能(neng)造成重大事故。為(wei)了(le)預防這種現象(xiang),在上(shang)述裝置(zhi)中(zhong)需要將(jiang)鋁(lv)導體與(yu)銅(tong)(tong)(tong)導體連(lian)接(jie)時(shi),采(cai)用一(yi)頭(tou)為(wei)鋁(lv),另(ling)一(yi)頭(tou)為(wei)銅(tong)(tong)(tong)的特殊過渡觸(chu)(chu)頭(tou)。
普通(tong)連(lian)接(jie)。普通(tong)連(lian)接(jie)在變壓(ya)器上是相當多(duo)的(de)(de),它們(men)都是過(guo)熱的(de)(de)重點部位,對平(ping)面接(jie)頭,對接(jie)面加(jia)工成(cheng)平(ping)面,清除平(ping)面上的(de)(de)雜(za)質,最好均勻地涂上導電膏,確保(bao)連(lian)接(jie)良好。
油浸(jin)電(dian)容式套(tao)管(guan)過熱。處理的辦法可以(yi)用定位套(tao)固定方(fang)式的發熱套(tao)管(guan),先(xian)拆開將(jiang)(jiang)軍帽(mao)(mao),若將(jiang)(jiang)軍帽(mao)(mao)、引線(xian)接頭絲扣有燒損,應(ying)用牙攻進行修(xiu)理,確保絲扣配合(he)良好(hao),然(ran)后在定位套(tao)和(he)將(jiang)(jiang)軍帽(mao)(mao)之間(jian)墊一(yi)個和(he)定位套(tao)截(jie)面大小(xiao)一(yi)致、厚度適宜的薄墊片,重新(xin)安裝(zhuang)將(jiang)(jiang)軍帽(mao)(mao),使將(jiang)(jiang)軍帽(mao)(mao)在擰緊情(qing)況下(xia),正好(hao)可以(yi)固定在套(tao)管(guan)頂(ding)部法蘭上。
引線接頭和將(jiang)軍帽絲扣公差配合應(ying)良好,否則應(ying)予以更換,以確保在擰(ning)緊(jin)的情況下,絲扣之間(jian)有足夠的壓力,減小接觸(chu)電阻。
篇9
【關(guan)鍵詞】發(fa)電(dian)(dian)廠;繼電(dian)(dian)保護;裝置性能
1.引言
在(zai)(zai)電(dian)(dian)力系(xi)統中,繼(ji)電(dian)(dian)保(bao)護裝置作為重要(yao)的安全衛(wei)士可以在(zai)(zai)短(duan)時間內將故(gu)障隔離,從而防(fang)止故(gu)障的繼(ji)續蔓延,對(dui)(dui)電(dian)(dian)網造成更大的危害。在(zai)(zai)電(dian)(dian)廠中使用繼(ji)電(dian)(dian)保(bao)護裝置同(tong)樣重要(yao)。就繼(ji)電(dian)(dian)保(bao)護技術(shu)本(ben)來來說,其技術(shu)性較強,其關鍵技術(shu)體現在(zai)(zai)分析故(gu)障和(he)處理故(gu)障上。本(ben)文對(dui)(dui)此進(jin)行了探討。
2.發(fa)電廠繼電保(bao)護(hu)作(zuo)用及要求分析(xi)
將繼(ji)電保護技(ji)術應用于發(fa)(fa)電廠(chang)中,主要(yao)原理是檢測(ce)系統(tong)出(chu)現的(de)(de)異(yi)常信號并給(gei)出(chu)報警,同時將故(gu)障(zhang)(zhang)自動切(qie)離系統(tong),提前對可(ke)能出(chu)現的(de)(de)故(gu)障(zhang)(zhang)進(jin)(jin)行(xing)(xing)防范。具體而言,繼(ji)電保護在(zai)發(fa)(fa)電廠(chang)中的(de)(de)作用表現為:進(jin)(jin)行(xing)(xing)故(gu)障(zhang)(zhang)監(jian)測(ce),如(ru):在(zai)設備(bei)發(fa)(fa)生(sheng)故(gu)障(zhang)(zhang)之前,繼(ji)電保護裝置(zhi)能夠進(jin)(jin)行(xing)(xing)異(yi)常信號的(de)(de)感知,并將故(gu)障(zhang)(zhang)切(qie)離系統(tong),有效防止了元件的(de)(de)損壞;另外,繼(ji)電保護裝置(zhi)在(zai)處理故(gu)障(zhang)(zhang)時十分迅速,可(ke)以避免停電。分析繼(ji)電保護的(de)(de)基本(ben)要(yao)求,由(you)于它(ta)要(yao)完成檢測(ce)、報警、故(gu)障(zhang)(zhang)隔離等多種(zhong)功(gong)能[1];因此,滿足(zu)繼(ji)電保護裝置(zhi)運行(xing)(xing)的(de)(de)基本(ben)要(yao)求是非(fei)常有必要(yao)的(de)(de),應該符(fu)合其選擇(ze)性、靈敏性和速度性。
3.繼(ji)電保護(hu)裝置工作原理分(fen)析
在發電(dian)(dian)廠中(zhong),常(chang)常(chang)會出(chu)現設(she)備線路故(gu)(gu)障(zhang)(zhang)現象(xiang),這些故(gu)(gu)障(zhang)(zhang)必(bi)然會導致系(xi)統(tong)電(dian)(dian)流和電(dian)(dian)壓的(de)(de)改變(bian),如(ru)果改變(bian)值超出(chu)了系(xi)統(tong)所能夠承受(shou)的(de)(de)范(fan)圍,智能控制系(xi)統(tong)會給(gei)出(chu)相應的(de)(de)報警(jing)信號(hao),技術人員也可(ke)以(yi)直接向斷(duan)(duan)路器(qi)給(gei)出(chu)斷(duan)(duan)開指令,以(yi)此實現故(gu)(gu)障(zhang)(zhang)的(de)(de)隔離,盡可(ke)能的(de)(de)減少故(gu)(gu)障(zhang)(zhang)所涉及的(de)(de)范(fan)圍,這就是繼(ji)電(dian)(dian)保護裝(zhuang)置(zhi)(zhi)的(de)(de)工作原理(li)。就其(qi)本(ben)質來說,它是對系(xi)統(tong)中(zhong)的(de)(de)故(gu)(gu)障(zhang)(zhang)電(dian)(dian)流、故(gu)(gu)障(zhang)(zhang)電(dian)(dian)壓或(huo)者(zhe)是其(qi)他參數(shu)的(de)(de)變(bian)化(hua)進行監(jian)測,從而做出(chu)判斷(duan)(duan),給(gei)出(chu)動作指令。同(tong)時(shi),繼(ji)電(dian)(dian)保護裝(zhuang)置(zhi)(zhi)也可(ke)以(yi)依據實際需要,將動作依據設(she)定為(wei)其(qi)他參數(shu),如(ru):在變(bian)壓器(qi)油箱中(zhong),可(ke)以(yi)將瓦(wa)斯的(de)(de)變(bian)化(hua)設(she)定為(wei)其(qi)故(gu)(gu)障(zhang)(zhang)的(de)(de)參考信號(hao)。不管(guan)是采用(yong)什么參數(shu),其(qi)基本(ben)原理(li)和結構都(dou)是類似的(de)(de);包(bao)括(kuo):測量裝(zhuang)置(zhi)(zhi)、邏輯裝(zhuang)置(zhi)(zhi)以(yi)及執行裝(zhuang)置(zhi)(zhi)[2]。
4.繼電保護(hu)裝置基(ji)本性能
分析繼電(dian)保護裝置的(de)基本(ben)性(xing)能,主要有(you)以下幾點:
1)可靠性
繼電保護裝置(zhi)的(de)可(ke)靠(kao)性(xing)直接關系到其使用效(xiao)果;其可(ke)靠(kao)性(xing)主要(yao)(yao)(yao)表現在兩(liang)個(ge)方面(mian),一是(shi)故障動作(zuo)(zuo)的(de)準確性(xing),另一個(ge)是(shi)不(bu)(bu)會(hui)產(chan)生誤(wu)動作(zuo)(zuo)。可(ke)靠(kao)性(xing)是(shi)最基本(ben)的(de)要(yao)(yao)(yao)求,對此(ci),需要(yao)(yao)(yao)從多(duo)個(ge)方面(mian)來保證:在配置(zhi)上要(yao)(yao)(yao)合理,裝置(zhi)的(de)制造(zao)質量要(yao)(yao)(yao)過關,技(ji)術(shu)性(xing)能(neng)要(yao)(yao)(yao)滿足要(yao)(yao)(yao)求等。在電廠中,電力(li)設備通常都有(you)兩(liang)個(ge)獨立的(de)回路,在斷(duan)路器上分別裝有(you)不(bu)(bu)同(tong)的(de)繼電保護裝置(zhi),兩(liang)套設備互補,以實現對線路的(de)保護。
2)選擇性
在(zai)電廠中(zhong),繼電保護(hu)裝(zhuang)置需(xu)要進行故(gu)障判斷(duan),在(zai)決策(ce)制定時存在(zai)一定的(de)(de)選擇性,是先(xian)斷(duan)開故(gu)障的(de)(de)設(she)備還是先(xian)斷(duan)開故(gu)障的(de)(de)線(xian)路;此外,裝(zhuang)置中(zhong)的(de)(de)保護(hu)元(yuan)件也(ye)具有選擇性,需(xu)要配(pei)合(he)其靈(ling)敏(min)系(xi)數,以實現對設(she)備和(he)線(xian)路的(de)(de)保護(hu)。
3)靈敏性
繼電保護的(de)靈(ling)(ling)敏性可以通(tong)過靈(ling)(ling)敏系(xi)數(shu)(shu)(shu)體(ti)現,它是(shi)指能(neng)夠允許的(de)電流(liu)和(he)電阻(zu)的(de)變化范圍。一旦電流(liu)超出靈(ling)(ling)敏系(xi)數(shu)(shu)(shu)范圍,裝置(zhi)就會(hui)啟(qi)動隔離功能(neng)。通(tong)過整定的(de)方式可以實現靈(ling)(ling)敏系(xi)數(shu)(shu)(shu)和(he)選擇性的(de)確(que)定。
4)快速反應性
繼電保護的快速(su)性要求很(hen)容易被理解,當故障出現時,只有快速(su)的將其(qi)隔(ge)離出去,才能保證其(qi)對系統造(zao)成的傷害(hai)最小。
5.繼電(dian)保護(hu)裝置的應用
繼電保(bao)護裝置在發電廠中的具體應用(yong)體現(xian)在以(yi)下幾個方面。
5.1 對(dui)發電變壓器組的保護(hu)
繼(ji)電(dian)(dian)保(bao)(bao)護(hu)(hu)(hu)(hu)(hu)裝置(zhi)(zhi)(zhi)在(zai)(zai)保(bao)(bao)護(hu)(hu)(hu)(hu)(hu)發電(dian)(dian)廠中的(de)(de)發電(dian)(dian)變壓(ya)器組時(shi),需要對機(ji)(ji)組的(de)(de)型號予以(yi)(yi)(yi)充分的(de)(de)考慮(lv);如:在(zai)(zai)某一大型的(de)(de)發電(dian)(dian)廠中,機(ji)(ji)組等設(she)備的(de)(de)造價很高(gao),維護(hu)(hu)(hu)(hu)(hu)起來十(shi)(shi)分復雜(za),停機(ji)(ji)檢修會造成較大的(de)(de)經濟損失。對此(ci)(ci),在(zai)(zai)使用(yong)(yong)繼(ji)電(dian)(dian)保(bao)(bao)護(hu)(hu)(hu)(hu)(hu)裝置(zhi)(zhi)(zhi)時(shi),要求其(qi)配置(zhi)(zhi)(zhi)可靠、靈(ling)敏并且快速。考慮(lv)到該電(dian)(dian)廠的(de)(de)實(shi)(shi)際情況(kuang),在(zai)(zai)對發電(dian)(dian)機(ji)(ji)和變壓(ya)器進(jin)行保(bao)(bao)護(hu)(hu)(hu)(hu)(hu)時(shi),選擇了G60以(yi)(yi)(yi)及(ji)T60等保(bao)(bao)護(hu)(hu)(hu)(hu)(hu)設(she)備;在(zai)(zai)對廠用(yong)(yong)變壓(ya)器以(yi)(yi)(yi)及(ji)勵磁變壓(ya)器進(jin)行保(bao)(bao)護(hu)(hu)(hu)(hu)(hu)時(shi),采用(yong)(yong)了C30保(bao)(bao)護(hu)(hu)(hu)(hu)(hu)設(she)備。采用(yong)(yong)的(de)(de)這(zhe)些保(bao)(bao)護(hu)(hu)(hu)(hu)(hu)裝置(zhi)(zhi)(zhi)具有十(shi)(shi)分成熟的(de)(de)技術,功能十(shi)(shi)分全面,在(zai)(zai)其(qi)硬件上包含有能夠(gou)實(shi)(shi)現(xian)數組控制的(de)(de)相應(ying)處(chu)理(li)器和芯片。可以(yi)(yi)(yi)采用(yong)(yong)DSP進(jin)行數據(ju)處(chu)理(li);因(yin)此(ci)(ci),保(bao)(bao)護(hu)(hu)(hu)(hu)(hu)裝置(zhi)(zhi)(zhi)的(de)(de)效(xiao)率能夠(gou)得(de)到提高(gao)。在(zai)(zai)實(shi)(shi)際應(ying)用(yong)(yong)中,可以(yi)(yi)(yi)依據(ju)具體情況(kuang)對保(bao)(bao)護(hu)(hu)(hu)(hu)(hu)裝置(zhi)(zhi)(zhi)進(jin)行靈(ling)活選擇,其(qi)依據(ju)是:發電(dian)(dian)機(ji)(ji)組的(de)(de)型號、電(dian)(dian)氣(qi)控制系統的(de)(de)具體特點等;只有這(zhe)樣才能保(bao)(bao)證保(bao)(bao)護(hu)(hu)(hu)(hu)(hu)與(yu)運行控制之(zhi)間的(de)(de)良(liang)好配合(he)。另外,還應(ying)該考慮(lv)到裝置(zhi)(zhi)(zhi)的(de)(de)經濟性(xing)和維護(hu)(hu)(hu)(hu)(hu)方(fang)面。
5.2 對發電廠電力(li)系統的保護
機(ji)電(dian)(dian)(dian)(dian)(dian)保(bao)護(hu)裝(zhuang)置(zhi)(zhi)在(zai)(zai)進行(xing)電(dian)(dian)(dian)(dian)(dian)廠(chang)電(dian)(dian)(dian)(dian)(dian)力系(xi)統(tong)(tong)(tong)保(bao)護(hu)時,需要充分考慮配合性,即(ji):基于合理減少二(er)次電(dian)(dian)(dian)(dian)(dian)纜,有(you)效提(ti)高(gao)對(dui)應網(wang)絡的(de)自(zi)動(dong)化(hua)水(shui)平(ping)。如:在(zai)(zai)某發電(dian)(dian)(dian)(dian)(dian)廠(chang)中,將(jiang)一套(tao)電(dian)(dian)(dian)(dian)(dian)廠(chang)用(yong)電(dian)(dian)(dian)(dian)(dian)監控(kong)(kong)(kong)系(xi)統(tong)(tong)(tong)配置(zhi)(zhi)在(zai)(zai)兩臺低壓機(ji)組上,另外(wai),將(jiang)系(xi)統(tong)(tong)(tong)與上層的(de)DCS相連接(jie),并通(tong)過通(tong)信(xin)(xin)網(wang)絡與繼電(dian)(dian)(dian)(dian)(dian)保(bao)護(hu)裝(zhuang)置(zhi)(zhi)相連接(jie);利用(yong)監控(kong)(kong)(kong)系(xi)統(tong)(tong)(tong)可以(yi)(yi)實(shi)現(xian)對(dui)電(dian)(dian)(dian)(dian)(dian)度量(liang)的(de)采集,并完(wan)成傳輸,最(zui)終實(shi)現(xian)對(dui)保(bao)護(hu)動(dong)作(zuo)量(liang)的(de)遙測以(yi)(yi)及通(tong)信(xin)(xin)。這種(zhong)方式最(zui)終實(shi)現(xian)了對(dui)電(dian)(dian)(dian)(dian)(dian)源(yuan)及保(bao)護(hu)裝(zhuang)置(zhi)(zhi)的(de)控(kong)(kong)(kong)制,它不(bu)僅提(ti)供(gong)開關遙控(kong)(kong)(kong),還可以(yi)(yi)實(shi)現(xian)保(bao)護(hu)定值的(de)查詢和修改;自(zi)動(dong)化(hua)控(kong)(kong)(kong)制的(de)可控(kong)(kong)(kong)性提(ti)高(gao)了,整個發電(dian)(dian)(dian)(dian)(dian)廠(chang)的(de)電(dian)(dian)(dian)(dian)(dian)力系(xi)統(tong)(tong)(tong)更加安全。
5.3 對發(fa)電廠直流系(xi)統的保護
在(zai)發(fa)電(dian)(dian)廠(chang)(chang)中,直流(liu)(liu)(liu)系(xi)(xi)統(tong)(tong)(tong)是重要的(de)(de)組成(cheng)部分(fen),它為保(bao)護、開關以及自(zi)動裝置(zhi)等提(ti)供(gong)直流(liu)(liu)(liu)電(dian)(dian)[3]。因此(ci),保(bao)證直流(liu)(liu)(liu)系(xi)(xi)統(tong)(tong)(tong)的(de)(de)可靠穩定對(dui)于(yu)整個電(dian)(dian)廠(chang)(chang)來說意義重大,它同時也是繼電(dian)(dian)保(bao)護裝置(zhi)準確動作的(de)(de)前提(ti)條(tiao)件(jian)和有力保(bao)障。對(dui)于(yu)廠(chang)(chang)用直流(liu)(liu)(liu)系(xi)(xi)統(tong)(tong)(tong)而言,其配置(zhi)原則依(yi)據的(de)(de)是電(dian)(dian)氣一次系(xi)(xi)統(tong)(tong)(tong)的(de)(de)分(fen)區(qu);考慮到(dao)直流(liu)(liu)(liu)系(xi)(xi)統(tong)(tong)(tong)的(de)(de)遠近,可以實現直流(liu)(liu)(liu)系(xi)(xi)統(tong)(tong)(tong)的(de)(de)冗余(yu)配置(zhi)。如(ru):在(zai)某發(fa)電(dian)(dian)廠(chang)(chang)中,由一套直流(liu)(liu)(liu)供(gong)電(dian)(dian)系(xi)(xi)統(tong)(tong)(tong)負責機組主廠(chang)(chang)房發(fa)電(dian)(dian)機組、自(zi)動控制(zhi)裝置(zhi)、輸煤系(xi)(xi)統(tong)(tong)(tong)保(bao)護等供(gong)電(dian)(dian)[4]。因此(ci),繼電(dian)(dian)保(bao)護裝置(zhi)需發(fa)電(dian)(dian)廠(chang)(chang)中的(de)(de)直流(liu)(liu)(liu)系(xi)(xi)統(tong)(tong)(tong)實施(shi)保(bao)護。
6.結束語
本文分析了(le)(le)電(dian)(dian)廠(chang)(chang)中繼電(dian)(dian)保(bao)(bao)(bao)護(hu)(hu)的(de)作用,對(dui)其工作原理進行了(le)(le)闡述(shu),重點對(dui)其基本性(xing)(xing)能(neng)和特殊處理以(yi)及(ji)具(ju)體(ti)(ti)應(ying)用進行了(le)(le)探討(tao)。總而言(yan)之,發(fa)(fa)電(dian)(dian)廠(chang)(chang)中的(de)繼電(dian)(dian)保(bao)(bao)(bao)護(hu)(hu)裝置(zhi)(zhi)應(ying)用十分普遍。繼電(dian)(dian)保(bao)(bao)(bao)護(hu)(hu)裝置(zhi)(zhi)不僅需要具(ju)備(bei)共性(xing)(xing)的(de)功能(neng)和性(xing)(xing)能(neng),還應(ying)該(gai)依據發(fa)(fa)電(dian)(dian)廠(chang)(chang)的(de)實(shi)際情況(kuang),在(zai)保(bao)(bao)(bao)證可(ke)靠(kao)性(xing)(xing)、選擇性(xing)(xing)和靈敏性(xing)(xing)的(de)前提下(xia),針(zhen)對(dui)具(ju)體(ti)(ti)網(wang)絡實(shi)施保(bao)(bao)(bao)護(hu)(hu)。另外(wai),為了(le)(le)滿足發(fa)(fa)電(dian)(dian)廠(chang)(chang)智能(neng)化(hua)生產的(de)需要,在(zai)選擇繼電(dian)(dian)保(bao)(bao)(bao)護(hu)(hu)裝置(zhi)(zhi)時,應(ying)該(gai)配合自動控制系統,實(shi)現(xian)保(bao)(bao)(bao)護(hu)(hu)系統的(de)自動化(hua),從(cong)而提高保(bao)(bao)(bao)護(hu)(hu)效果。
參考文獻
[1]曹汝鵬.電廠繼(ji)電保護裝(zhuang)置的應用與檢修(xiu)探討[J].電力技術,2009(22).
[2]張兵海,王獻(xian)志,李曉文.抽水蓄能(neng)機組幾(ji)種特殊發變組保(bao)護整定配置原則探討[J].水電(dian)自(zi)動化與大(da)壩監(jian)測,2010(1).
篇10
關鍵(jian)詞:變壓器;鐵(tie)芯故障;故障診斷;故障排除(chu);繞組
中(zhong)圖分類號(hao):TM401文(wen)獻標(biao)識(shi)碼:A文(wen)章編號(hao):1009-2374(2009)20-0026-03
近年來,隨著用電(dian)的(de)(de)工業化、商業化的(de)(de)出現,每年都(dou)在不斷提高(gao)電(dian)力系統的(de)(de)供(gong)(gong)電(dian)可(ke)(ke)靠性(xing)和供(gong)(gong)電(dian)質量。供(gong)(gong)電(dian)可(ke)(ke)靠性(xing)要(yao)得到真(zhen)正意(yi)義上的(de)(de)提高(gao),我們必須對(dui)構(gou)成電(dian)力網中三(san)大部分(fen)進行關(guan)鍵性(xing)的(de)(de)提高(gao)。
電(dian)(dian)(dian)(dian)(dian)(dian)力(li)網是(shi)(shi)由(you)送電(dian)(dian)(dian)(dian)(dian)(dian)、變電(dian)(dian)(dian)(dian)(dian)(dian)、發(fa)電(dian)(dian)(dian)(dian)(dian)(dian)構成的(de),我(wo)們之所以(yi)(yi)得(de)到(dao)一(yi)(yi)(yi)(yi)個照(zhao)明系統常用的(de)220V電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya),中間(jian)是(shi)(shi)經(jing)過(guo)了發(fa)電(dian)(dian)(dian)(dian)(dian)(dian)廠、變電(dian)(dian)(dian)(dian)(dian)(dian)站、配電(dian)(dian)(dian)(dian)(dian)(dian)所的(de)電(dian)(dian)(dian)(dian)(dian)(dian)力(li)變壓(ya)(ya)(ya)器(qi)(qi),發(fa)電(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)由(you)于(yu)其本身絕緣(yuan)限制,一(yi)(yi)(yi)(yi)般電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)等級在(zai)(zai)6kV、10kV,如果(guo)不通(tong)過(guo)升壓(ya)(ya)(ya)變壓(ya)(ya)(ya)器(qi)(qi)進行遠(yuan)距離輸(shu)送電(dian)(dian)(dian)(dian)(dian)(dian)能的(de)話,必然(ran)會(hui)導致功率損(sun)耗大,嚴(yan)重影(ying)響供(gong)電(dian)(dian)(dian)(dian)(dian)(dian)質量(liang)和(he)可(ke)靠性(xing),為了減少(shao)輸(shu)電(dian)(dian)(dian)(dian)(dian)(dian)線(xian)路在(zai)(zai)線(xian)路阻抗(kang)的(de)作用下損(sun)耗過(guo)大的(de)功率,我(wo)們采用電(dian)(dian)(dian)(dian)(dian)(dian)力(li)變壓(ya)(ya)(ya)器(qi)(qi)對發(fa)電(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)的(de)輸(shu)出電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)進行升壓(ya)(ya)(ya)。由(you)于(yu)發(fa)電(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)的(de)輸(shu)出功率是(shi)(shi)一(yi)(yi)(yi)(yi)定的(de),提高電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)等級就(jiu)可(ke)以(yi)(yi)降低電(dian)(dian)(dian)(dian)(dian)(dian)流,當輸(shu)電(dian)(dian)(dian)(dian)(dian)(dian)線(xian)路上的(de)電(dian)(dian)(dian)(dian)(dian)(dian)流降低,其有功耗損(sun)也得(de)到(dao)一(yi)(yi)(yi)(yi)定的(de)降低。電(dian)(dian)(dian)(dian)(dian)(dian)力(li)變壓(ya)(ya)(ya)器(qi)(qi)不是(shi)(shi)永遠(yuan)沒有故(gu)(gu)(gu)障(zhang),據(ju)統計,電(dian)(dian)(dian)(dian)(dian)(dian)力(li)變壓(ya)(ya)(ya)器(qi)(qi)的(de)故(gu)(gu)(gu)障(zhang)占電(dian)(dian)(dian)(dian)(dian)(dian)氣設備總故(gu)(gu)(gu)障(zhang)的(de)30%,而(er)且(qie)變壓(ya)(ya)(ya)器(qi)(qi)故(gu)(gu)(gu)障(zhang)的(de)多樣化(hua)造成查找困難,加上設備的(de)限制,很多時候都是(shi)(shi)通(tong)過(guo)經(jing)驗判斷變壓(ya)(ya)(ya)器(qi)(qi)故(gu)(gu)(gu)障(zhang)是(shi)(shi)由(you)哪種原因造成,及(ji)時發(fa)現變壓(ya)(ya)(ya)器(qi)(qi)存在(zai)(zai)故(gu)(gu)(gu)障(zhang)、及(ji)時排除故(gu)(gu)(gu)障(zhang)可(ke)以(yi)(yi)延(yan)長變壓(ya)(ya)(ya)器(qi)(qi)的(de)使用壽命(ming),是(shi)(shi)提高供(gong)電(dian)(dian)(dian)(dian)(dian)(dian)可(ke)靠性(xing)的(de)手段(duan)之一(yi)(yi)(yi)(yi)。
一、變壓器的用途、分類與工作原(yuan)理
(一(yi))變壓(ya)器(qi)的用途
變壓(ya)(ya)器(qi)是(shi)利用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)感應,以相同的(de)(de)(de)頻率(lv),在(zai)(zai)兩(liang)個或更多(duo)的(de)(de)(de)繞組之(zhi)間變換交換電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)或電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)的(de)(de)(de)一(yi)(yi)(yi)種(zhong)靜止電(dian)(dian)(dian)(dian)(dian)(dian)(dian)氣(qi)設備(bei)(bei)。各種(zhong)不(bu)同的(de)(de)(de)用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)設備(bei)(bei)常常需(xu)要不(bu)同電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan),我們日常生活用(yong)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)燈、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)器(qi)的(de)(de)(de)工作電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)為220V;安全照明用(yong)燈的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)為36V、24V或12V;三相交流(liu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)動機一(yi)(yi)(yi)般用(yong)380V電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)。從電(dian)(dian)(dian)(dian)(dian)(dian)(dian)力系統(tong)的(de)(de)(de)角(jiao)度來看,一(yi)(yi)(yi)個電(dian)(dian)(dian)(dian)(dian)(dian)(dian)力網(wang)將許多(duo)發電(dian)(dian)(dian)(dian)(dian)(dian)(dian)廠和(he)用(yong)戶聯系在(zai)(zai)一(yi)(yi)(yi)起,分(fen)成主系統(tong)必須是(shi)統(tong)一(yi)(yi)(yi)的(de)(de)(de)一(yi)(yi)(yi)種(zhong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)等(deng)級(ji),這(zhe)也需(xu)要各種(zhong)規格(ge)和(he)容量的(de)(de)(de)變壓(ya)(ya)器(qi)來連接(jie)各個系統(tong)。所以說電(dian)(dian)(dian)(dian)(dian)(dian)(dian)力變壓(ya)(ya)器(qi)是(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)力系統(tong)中不(bu)可(ke)缺少的(de)(de)(de)一(yi)(yi)(yi)種(zhong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)氣(qi)設備(bei)(bei)。
在(zai)實際工(gong)作中,變壓(ya)器除了用(yong)(yong)來變換電壓(ya)外(wai),還(huan)用(yong)(yong)來變換交流(liu)電流(liu),交換阻(zu)抗,改(gai)變相位等。
(二)變壓器(qi)的分類(lei)
變(bian)壓器有不(bu)同的使(shi)用條(tiao)件、安(an)裝場所,有不(bu)同的電(dian)壓等級(ji)和容量級(ji)別(bie),有不(bu)同的結構形式(shi)和制冷方式(shi),所以(yi)應(ying)按不(bu)同原則進行(xing)分類。
1.按用途不同。變壓器(qi)(qi)分為(wei)電力變壓器(qi)(qi),特種變壓器(qi)(qi),儀用互(hu)感器(qi)(qi)、試驗用的(de)高壓變壓器(qi)(qi)和(he)調壓器(qi)(qi)等(deng)。
2.按繞組構(gou)成(cheng)不同。變壓器(qi)分為雙繞組,三繞組、多繞組變壓器(qi)和自耦變壓器(qi)。
3.按鐵芯結構(gou)不(bu)同。變壓器(qi)分(fen)為芯式(shi)和殼式(shi)變壓器(qi)。
4.按相(xiang)(xiang)數(shu)的不(bu)同。變壓器分為(wei)單相(xiang)(xiang)、三相(xiang)(xiang)、多相(xiang)(xiang)變壓器。
5.按(an)調(diao)壓方式不同。變(bian)壓器分為無(wu)勵磁調(diao)壓變(bian)壓器,有載調(diao)壓變(bian)壓器。
6.按冷(leng)卻方式不同。變(bian)(bian)(bian)壓(ya)器(qi)(qi)(qi)分為(wei)干式變(bian)(bian)(bian)壓(ya)器(qi)(qi)(qi)、油(you)(you)浸自冷(leng)變(bian)(bian)(bian)壓(ya)器(qi)(qi)(qi)、油(you)(you)浸風冷(leng)變(bian)(bian)(bian)壓(ya)器(qi)(qi)(qi)、強迫油(you)(you)循環(huan)變(bian)(bian)(bian)壓(ya)器(qi)(qi)(qi)、強迫循環(huan)導向冷(leng)卻變(bian)(bian)(bian)壓(ya)器(qi)(qi)(qi)、充氣式變(bian)(bian)(bian)壓(ya)器(qi)(qi)(qi)。
7.按線(xian)圈結構不同。變(bian)(bian)壓(ya)(ya)器(qi)分為單(dan)線(xian)圈變(bian)(bian)壓(ya)(ya)器(qi)、雙線(xian)圈變(bian)(bian)壓(ya)(ya)器(qi)、三線(xian)圈變(bian)(bian)壓(ya)(ya)器(qi)及多線(xian)圈變(bian)(bian)壓(ya)(ya)器(qi)。
8.按(an)中心(xin)點(dian)絕(jue)緣不同。變壓(ya)器分為全絕(jue)緣變壓(ya)器和(he)半(ban)絕(jue)緣變壓(ya)器。
(三)變壓(ya)器工作原(yuan)理(li)
變壓(ya)器的基(ji)本原理(li)是(shi)電(dian)磁感(gan)應(ying)原理(li),現以單相雙繞組變壓(ya)器為例說明其(qi)基(ji)本工作原理(li)(如上(shang)圖所(suo)示):當一次側(ce)繞組上(shang)加上(shang)電(dian)壓(ya) 1時,流過電(dian)流 1,在(zai)鐵芯中(zhong)就產生交變磁通1,這(zhe)些磁通稱(cheng)為主磁通,在(zai)它作用(yong)下,兩側(ce)繞組分別感(gan)應(ying)電(dian)勢 1, 2,感(gan)應(ying)電(dian)勢公式(shi)為:E=4.44fNm。
式中:E――感應電勢有(you)效值;F――頻(pin)率;N――匝數(shu);m――主磁通最大值。
由于二次繞組與一次繞組匝(za)數不同(tong),感應電(dian)勢 1和 2大(da)(da)小也不同(tong),當略(lve)去內阻(zu)抗壓降后,電(dian)壓 1和 2大(da)(da)小也就不同(tong)。
當(dang)變(bian)(bian)壓(ya)器(qi)二次(ci)側(ce)(ce)空載(zai)時,一次(ci)側(ce)(ce)僅流(liu)(liu)過主(zhu)磁(ci)(ci)通的電(dian)(dian)(dian)(dian)流(liu)(liu)( 0),這個(ge)電(dian)(dian)(dian)(dian)流(liu)(liu)稱為激(ji)磁(ci)(ci)電(dian)(dian)(dian)(dian)流(liu)(liu)。當(dang)二次(ci)側(ce)(ce)加負(fu)載(zai)流(liu)(liu)過負(fu)載(zai)電(dian)(dian)(dian)(dian)流(liu)(liu) 2時,也(ye)在鐵芯中產(chan)生(sheng)磁(ci)(ci)通,力圖改變(bian)(bian)主(zhu)磁(ci)(ci)通,但一次(ci)電(dian)(dian)(dian)(dian)壓(ya)不變(bian)(bian)時,主(zhu)磁(ci)(ci)通是不變(bian)(bian)的,一次(ci)側(ce)(ce)就(jiu)(jiu)要流(liu)(liu)過兩部(bu)(bu)(bu)分電(dian)(dian)(dian)(dian)流(liu)(liu),一部(bu)(bu)(bu)分為激(ji)磁(ci)(ci)電(dian)(dian)(dian)(dian)流(liu)(liu) 0,一部(bu)(bu)(bu)分用來平衡 2,所以這部(bu)(bu)(bu)分電(dian)(dian)(dian)(dian)流(liu)(liu)隨(sui)著(zhu) 2變(bian)(bian)化而變(bian)(bian)化。當(dang)電(dian)(dian)(dian)(dian)流(liu)(liu)乘(cheng)以匝(za)數時,就(jiu)(jiu)是磁(ci)(ci)勢(shi)。
上(shang)述的(de)平衡作(zuo)用(yong)實(shi)(shi)質(zhi)上(shang)是磁(ci)勢平衡作(zuo)用(yong),變壓器就(jiu)是通過磁(ci)勢平衡作(zuo)用(yong)實(shi)(shi)現了一、二次側的(de)能量傳遞。
二(er)、變壓器鐵芯故障
(一)鐵芯故障的種類
鐵芯(xin)有兩大基本結(jie)構開(kai)式(shi),即殼式(shi)和芯(xin)式(shi),它們的(de)主要區別(bie)在于磁路即鐵芯(xin)與繞組(zu)的(de)相對位(wei)置,繞組(zu)被鐵芯(xin)包圍的(de)稱為(wei)殼式(shi);鐵芯(xin)被繞組(zu)包圍時稱為(wei)芯(xin)式(shi)。
芯(xin)(xin)(xin)式(shi)(shi)變(bian)(bian)壓(ya)(ya)器(qi)特點是(shi)(shi)繞組(zu)包(bao)圍(wei)(wei)鐵(tie)(tie)芯(xin)(xin)(xin),鐵(tie)(tie)芯(xin)(xin)(xin)處于器(qi)身內(nei)芯(xin)(xin)(xin),故稱(cheng)(cheng)芯(xin)(xin)(xin)式(shi)(shi)或內(nei)芯(xin)(xin)(xin)式(shi)(shi),判(pan)斷的(de)(de)標準是(shi)(shi)總(zong)有幾(ji)個繞組(zu)的(de)(de)一邊沒有鐵(tie)(tie)芯(xin)(xin)(xin)或鐵(tie)(tie)軛而殼式(shi)(shi)變(bian)(bian)壓(ya)(ya)器(qi)特點是(shi)(shi)鐵(tie)(tie)芯(xin)(xin)(xin)包(bao)圍(wei)(wei)繞組(zu),故稱(cheng)(cheng)殼式(shi)(shi)變(bian)(bian)壓(ya)(ya)器(qi)或外(wai)鐵(tie)(tie)式(shi)(shi)變(bian)(bian)壓(ya)(ya)器(qi)。它主要用在家用視頻電器(qi)或特大型變(bian)(bian)壓(ya)(ya)器(qi)上(shang),可(ke)拆分小(xiao)件到現(xian)場組(zu)成整(zheng)體變(bian)(bian)壓(ya)(ya)器(qi),一般(ban)情況下殼式(shi)(shi)鐵(tie)(tie)芯(xin)(xin)(xin)是(shi)(shi)水平放置,芯(xin)(xin)(xin)式(shi)(shi)鐵(tie)(tie)芯(xin)(xin)(xin)是(shi)(shi)垂直放置的(de)(de),大容量的(de)(de)芯(xin)(xin)(xin)式(shi)(shi)變(bian)(bian)壓(ya)(ya)器(qi)由于運輸高度所限、壓(ya)(ya)縮了上(shang)下鐵(tie)(tie)軛的(de)(de)高度,以增加旁(pang)軛的(de)(de)辦法增加磁(ci)路(lu)。將變(bian)(bian)壓(ya)(ya)器(qi)鐵(tie)(tie)芯(xin)(xin)(xin)做成單相三(san)柱(zhu)(一個芯(xin)(xin)(xin)柱(zhu))單相四(si)柱(zhu)(兩(liang)個芯(xin)(xin)(xin)柱(zhu))或三(san)相五柱(zhu)(三(san)個芯(xin)(xin)(xin)柱(zhu))。它們(men)仍保留芯(xin)(xin)(xin)式(shi)(shi)結構的(de)(de)特點,因此(ci)它們(men)雖有包(bao)圍(wei)(wei)繞組(zu)的(de)(de)旁(pang)軛,仍屬于芯(xin)(xin)(xin)式(shi)(shi)結構。
(二)鐵芯的結構
鐵(tie)芯(xin)(xin)(xin)(xin)(xin)(xin)的(de)(de)(de)(de)(de)(de)(de)夾緊(jin)(jin)一(yi)(yi)般(ban)有(you)兩(liang)種結(jie)構(gou)(gou)(gou)形式,一(yi)(yi)是(shi)鐵(tie)芯(xin)(xin)(xin)(xin)(xin)(xin)柱無孔(kong)綁扎(zha)及(ji)鐵(tie)軛上穿(chuan)螺桿(gan)的(de)(de)(de)(de)(de)(de)(de)結(jie)構(gou)(gou)(gou),另一(yi)(yi)個(ge)是(shi)鐵(tie)芯(xin)(xin)(xin)(xin)(xin)(xin)柱無孔(kong)綁扎(zha)及(ji)鐵(tie)軛無孔(kong)的(de)(de)(de)(de)(de)(de)(de)拉帶結(jie)構(gou)(gou)(gou)。(1)鐵(tie)芯(xin)(xin)(xin)(xin)(xin)(xin)的(de)(de)(de)(de)(de)(de)(de)鋼夾緊(jin)(jin)裝(zhuang)(zhuang)(zhuang)置(zhi)(zhi)(zhi)(zhi)是(shi)使整(zheng)個(ge)鐵(tie)芯(xin)(xin)(xin)(xin)(xin)(xin)構(gou)(gou)(gou)成(cheng)一(yi)(yi)個(ge)整(zheng)體(ti)的(de)(de)(de)(de)(de)(de)(de)堅(jian)固結(jie)構(gou)(gou)(gou),它的(de)(de)(de)(de)(de)(de)(de)結(jie)構(gou)(gou)(gou)應(ying)能(neng)(neng)(neng)滿足如下要求:夾緊(jin)(jin)裝(zhuang)(zhuang)(zhuang)置(zhi)(zhi)(zhi)(zhi)一(yi)(yi)般(ban)做成(cheng)框架式、此夾緊(jin)(jin)裝(zhuang)(zhuang)(zhuang)置(zhi)(zhi)(zhi)(zhi)的(de)(de)(de)(de)(de)(de)(de)結(jie)構(gou)(gou)(gou)上要保證(zheng)能(neng)(neng)(neng)承受(shou)鐵(tie)芯(xin)(xin)(xin)(xin)(xin)(xin)本體(ti)的(de)(de)(de)(de)(de)(de)(de)緊(jin)(jin)力;(2)夾緊(jin)(jin)裝(zhuang)(zhuang)(zhuang)置(zhi)(zhi)(zhi)(zhi)在結(jie)構(gou)(gou)(gou)上應(ying)能(neng)(neng)(neng)通過各類絕緣件(jian)(jian)(jian)可(ke)靠地(di)對繞(rao)組進行壓緊(jin)(jin),支(zhi)撐(cheng)所有(you)引線和(he)裝(zhuang)(zhuang)(zhuang)置(zhi)(zhi)(zhi)(zhi)器(qi)身(shen)上的(de)(de)(de)(de)(de)(de)(de)所有(you)絕緣件(jian)(jian)(jian)及(ji)組件(jian)(jian)(jian),并應(ying)具有(you)器(qi)身(shen)在油箱中(zhong)的(de)(de)(de)(de)(de)(de)(de)定位結(jie)構(gou)(gou)(gou)和(he)保證(zheng)器(qi)身(shen)運輸中(zhong)穩定的(de)(de)(de)(de)(de)(de)(de)定位結(jie)構(gou)(gou)(gou);(3)夾緊(jin)(jin)裝(zhuang)(zhuang)(zhuang)置(zhi)(zhi)(zhi)(zhi)與鐵(tie)芯(xin)(xin)(xin)(xin)(xin)(xin)相接(jie)觸的(de)(de)(de)(de)(de)(de)(de)面(mian)一(yi)(yi)定要平整(zheng),且夾緊(jin)(jin)裝(zhuang)(zhuang)(zhuang)置(zhi)(zhi)(zhi)(zhi)不(bu)得有(you)任何變(bian)形,以(yi)保證(zheng)鐵(tie)芯(xin)(xin)(xin)(xin)(xin)(xin)能(neng)(neng)(neng)夠均勻(yun)受(shou)力,鐵(tie)芯(xin)(xin)(xin)(xin)(xin)(xin)片的(de)(de)(de)(de)(de)(de)(de)邊(bian)緣應(ying)不(bu)出現翹起,鐵(tie)芯(xin)(xin)(xin)(xin)(xin)(xin)各處的(de)(de)(de)(de)(de)(de)(de)“波浪”應(ying)保證(zheng)最(zui)小,鐵(tie)芯(xin)(xin)(xin)(xin)(xin)(xin)勵磁時噪聲要符(fu)合(he)標準要求;(4)為防(fang)止鐵(tie)芯(xin)(xin)(xin)(xin)(xin)(xin)多點接(jie)地(di),結(jie)構(gou)(gou)(gou)鋼件(jian)(jian)(jian)應(ying)用(yong)專門的(de)(de)(de)(de)(de)(de)(de)絕緣件(jian)(jian)(jian)與鐵(tie)芯(xin)(xin)(xin)(xin)(xin)(xin)本體(ti)隔開(kai)(kai);(5)夾緊(jin)(jin)裝(zhuang)(zhuang)(zhuang)置(zhi)(zhi)(zhi)(zhi)與鐵(tie)芯(xin)(xin)(xin)(xin)(xin)(xin)相接(jie)觸處必須有(you)可(ke)靠的(de)(de)(de)(de)(de)(de)(de)絕緣件(jian)(jian)(jian)隔開(kai)(kai)。
(三)鐵芯接地
變壓器(qi)在(zai)(zai)運行中(zhong),鐵(tie)(tie)芯(xin)以及(ji)固定鐵(tie)(tie)芯(xin)的(de)(de)金(jin)屬結構(gou)零件(jian)、部(bu)(bu)件(jian)等,均(jun)處(chu)于在(zai)(zai)強電場(chang)中(zhong),在(zai)(zai)電場(chang)作(zuo)用(yong)下,它(ta)(ta)具(ju)有(you)較高的(de)(de)對(dui)地電位(wei)。如果鐵(tie)(tie)芯(xin)不(bu)(bu)接地,它(ta)(ta)與(yu)(yu)接地的(de)(de)夾件(jian)及(ji)油箱(xiang)之(zhi)(zhi)間(jian)就會(hui)有(you)電位(wei)差,在(zai)(zai)電位(wei)差的(de)(de)作(zuo)用(yong)下,會(hui)產生(sheng)斷續放電現(xian)象。另外,在(zai)(zai)繞組的(de)(de)周圍具(ju)有(you)較強的(de)(de)磁(ci)場(chang)。鐵(tie)(tie)芯(xin)和(he)零部(bu)(bu)件(jian)都處(chu)在(zai)(zai)非均(jun)勻的(de)(de)磁(ci)場(chang)中(zhong),它(ta)(ta)們與(yu)(yu)繞組的(de)(de)距離和(he)不(bu)(bu)相等,所(suo)以各零部(bu)(bu)件(jian)被(bei)感(gan)應出來(lai)的(de)(de)電動勢(shi)大小(xiao)也(ye)各不(bu)(bu)相等。彼(bi)此之(zhi)(zhi)間(jian)因(yin)而(er)也(ye)存在(zai)(zai)著電位(wei)差,鐵(tie)(tie)芯(xin)和(he)金(jin)屬構(gou)件(jian)上會(hui)產生(sheng)懸浮電位(wei)差,電位(wei)差雖然(ran)不(bu)(bu)大但也(ye)能擊穿很小(xiao)的(de)(de)間(jian)隙。因(yin)而(er)也(ye)會(hui)引起持續性的(de)(de)微量放電,這(zhe)些現(xian)象是(shi)不(bu)(bu)充許的(de)(de),而(er)要檢查這(zhe)些不(bu)(bu)斷續放電的(de)(de)部(bu)(bu)位(wei)是(shi)非常困難(nan)的(de)(de)。因(yin)此,必須(xu)將鐵(tie)(tie)芯(xin)以及(ji)固定鐵(tie)(tie)芯(xin)等金(jin)屬零部(bu)(bu)件(jian)可靠接地,使它(ta)(ta)們與(yu)(yu)油箱(xiang)同(tong)處(chu)于地電位(wei)。
鐵(tie)芯是由(you)許多層硅鋼片疊積(ji)而成,如(ru)果鐵(tie)芯有兩(liang)點(dian)或兩(liang)點(dian)以上接(jie)(jie)(jie)地(di),則鐵(tie)芯中(zhong)磁通(tong)變化時就會(hui)在接(jie)(jie)(jie)地(di)回(hui)路(lu)(lu)中(zhong)有感應環流,接(jie)(jie)(jie)地(di)點(dian)越(yue)多環流回(hui)路(lu)(lu)也(ye)越(yue)多。此環流將引起空載(zai)損耗增大(da)(da)、鐵(tie)芯溫度升(sheng)高(gao),當環流足夠大(da)(da)時,將燒毀(hui)接(jie)(jie)(jie)地(di)片產(chan)生故(gu)障,所以鐵(tie)芯必須一(yi)點(dian)接(jie)(jie)(jie)地(di)。
所謂鐵芯一(yi)(yi)點接(jie)地,只是指其磁導體而言,其夾件不受(shou)此限制(zhi)。鐵芯片與夾緊(jin)件要絕緣的(de)一(yi)(yi)個原因(yin)就是確保鐵芯一(yi)(yi)點接(jie)地。
鐵(tie)芯的(de)硅(gui)鋼(gang)(gang)(gang)(gang)片(pian)(pian)相互之間是(shi)絕緣(yuan)的(de),這(zhe)是(shi)為防止(zhi)(zhi)產生較大(da)的(de)渦流(liu),因此切不可(ke)將所有的(de)硅(gui)鋼(gang)(gang)(gang)(gang)片(pian)(pian)接(jie)(jie)地,否則將造成較大(da)的(de)渦流(liu)而使(shi)鐵(tie)芯發(fa)熱。么(me)鐵(tie)芯的(de)接(jie)(jie)地又是(shi)怎(zen)樣(yang)做的(de)呢?通常(chang)是(shi)將鐵(tie)芯的(de)任(ren)意(yi)一片(pian)(pian)硅(gui)鋼(gang)(gang)(gang)(gang)片(pian)(pian)接(jie)(jie)地。這(zhe)是(shi)因為硅(gui)鋼(gang)(gang)(gang)(gang)片(pian)(pian)之間雖然絕緣(yuan),但(dan)其絕緣(yuan)電阻極數值是(shi)很少的(de),不均勻的(de)強電場和磁場在硅(gui)鋼(gang)(gang)(gang)(gang)片(pian)(pian)中感應(ying)的(de)高壓負(fu)荷,可(ke)以(yi)通過硅(gui)鋼(gang)(gang)(gang)(gang)片(pian)(pian)從接(jie)(jie)地處流(liu)向大(da)地,但(dan)卻能阻止(zhi)(zhi)渦流(liu)從一片(pian)(pian)流(liu)向另一片(pian)(pian),所以(yi)若(ruo)將鐵(tie)芯任(ren)一片(pian)(pian)硅(gui)鋼(gang)(gang)(gang)(gang)片(pian)(pian)接(jie)(jie)地,哪么(me),整個鐵(tie)芯也就都接(jie)(jie)地了。
三、變(bian)壓器鐵芯故障診斷
(一)鐵(tie)芯多點接地(di)的常見原因與表(biao)現特征
統計(ji)資(zi)料表明,變(bian)壓(ya)器鐵芯多點(dian)接(jie)地故障(zhang)在(zai)變(bian)壓(ya)器總(zong)事故中占第三(san)位,主要原因是變(bian)壓(ya)器在(zai)現場裝配及(ji)施工中不慎,遺落金屬(shu)異物,造(zao)成多點(dian)接(jie)地或鐵軛與夾(jia)件短路,芯柱與夾(jia)件相碰等。鐵芯接(jie)地故障(zhang)可以(yi)根據(ju)以(yi)下三(san)方面(mian)的(de)征兆(zhao)作出判(pan)斷:
1.鐵(tie)芯局部過熱(re),使鐵(tie)芯損耗增(zeng)加(jia),甚至燒壞。
2.過(guo)熱(re)造成的溫升,將(jiang)使變(bian)壓器(qi)油(you)分解,產生(sheng)的氣體溶(rong)于油(you)中,引發(fa)絕(jue)緣油(you)性能(neng)下降(jiang)。
3.油中氣體(ti)不斷增加并析出(電(dian)弧放電(dian)故障時,氣體(ti)析出量較之(zhi)更快(kuai)),可能導致(zhi)氣體(ti)繼電(dian)器(qi)動作而使(shi)變壓器(qi)跳閘。
鐵(tie)芯(xin)多(duo)點(dian)接(jie)(jie)地時,正常接(jie)(jie)地點(dian)和故障接(jie)(jie)地點(dian)之(zhi)間形成一個閉(bi)合(he)回,當主磁通穿過(guo)這一回路時會感應電流(liu),此電流(liu)在兩接(jie)(jie)地點(dian)和鐵(tie)芯(xin)的(de)環(huan)(huan)路中流(liu)動,形成環(huan)(huan)流(liu)。環(huan)(huan)流(liu)使鐵(tie)芯(xin)局部過(guo)熱,導致與之(zhi)接(jie)(jie)觸(chu)的(de)絕緣油分解產生氣(qi)體(ti),并溶于變(bian)壓器油中,取油樣抽出氣(qi)體(ti)做色譜分析試(shi)驗,檢測出特征氣(qi)體(ti)(如(ru)H2,CH4,C2H2,C2H6,C2H2等,每次接(jie)(jie)地取兩組數據(ju))是判斷鐵(tie)芯(xin)接(jie)(jie)地的(de)依(yi)據(ju)。
(二)鐵芯(xin)多(duo)點接地的檢查方法(fa)
1.采用抽油樣,進行(xing)氣相色(se)譜分(fen)析。當變(bian)壓器發(fa)生故(gu)障時,為(wei)區分(fen)故(gu)障類別,可取油樣對油中含(han)(han)氣量(liang)及(ji)組(zu)分(fen)進行(xing)色(se)譜分(fen)析。(1)色(se)譜分(fen)析中如(ru)氣體中的甲烷(wan)(CH4)及(ji)烯烴組(zu)分(fen)含(han)(han)量(liang)較高,而(er)一氧化碳(CO)和二(er)氧化碳(CO2)氣體含(han)(han)量(liang)和以往相比變(bian)化不(bu)大,或含(han)(han)量(liang)正常,則說明鐵芯(xin)(xin)過熱(re),鐵芯(xin)(xin)過熱(re)可能(neng)是由于多(duo)點接(jie)地(di)所致;(2)色(se)譜分(fen)析中當出現(xian)乙(yi)炔(C2H2),說明鐵芯(xin)(xin)已出現(xian)間歇性多(duo)點接(jie)地(di)。
2.采用(yong)交流(liu)(liu)(liu)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)表(biao)(biao)測(ce)(ce)量(liang)(liang)接(jie)(jie)(jie)地(di)(di)(di)(di)線(xian)有(you)(you)無(wu)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)。因(yin)變壓器鐵(tie)(tie)芯接(jie)(jie)(jie)地(di)(di)(di)(di)導線(xian)和外(wai)引的接(jie)(jie)(jie)地(di)(di)(di)(di)套(tao)(tao)管相連接(jie)(jie)(jie),利用(yong)其外(wai)引接(jie)(jie)(jie)地(di)(di)(di)(di)套(tao)(tao)管,接(jie)(jie)(jie)入電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)表(biao)(biao),測(ce)(ce)量(liang)(liang)地(di)(di)(di)(di)線(xian)上有(you)(you)無(wu)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)。變壓器鐵(tie)(tie)芯正(zheng)常(chang)接(jie)(jie)(jie)地(di)(di)(di)(di)時(shi)(一點(dian)接(jie)(jie)(jie)地(di)(di)(di)(di)),因(yin)無(wu)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)回路形成(cheng),接(jie)(jie)(jie)地(di)(di)(di)(di)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)很少(shao)(在1A以下)或等于零;當鐵(tie)(tie)芯出現(xian)多(duo)(duo)點(dian)接(jie)(jie)(jie)地(di)(di)(di)(di)時(shi),鐵(tie)(tie)芯主磁通周圍有(you)(you)短路匝存在,匝內將有(you)(you)環(huan)流(liu)(liu)(liu)流(liu)(liu)(liu)通,其環(huan)流(liu)(liu)(liu)包(bao)圍的多(duo)(duo)少(shao)取決于磁通被包(bao)圍多(duo)(duo)少(shao)而定,一般(ban)可(ke)達(da)幾十(shi)安培。利用(yong)測(ce)(ce)量(liang)(liang)地(di)(di)(di)(di)線(xian)中有(you)(you)無(wu)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)存在可(ke)以正(zheng)確地(di)(di)(di)(di)判斷鐵(tie)(tie)芯有(you)(you)無(wu)多(duo)(duo)點(dian)接(jie)(jie)(jie)地(di)(di)(di)(di)故(gu)障。
3.交流法(fa)測定多點(dian)接地(di)(di)故(gu)障。交流法(fa)測量(liang),是用電流表(biao)測量(liang)接地(di)(di)系統中(zhong)有(you)(you)無交流電流存在。測量(liang)方法(fa)是先給(gei)變(bian)壓器(qi)低壓繞組施加220~380V的交流電壓,測量(liang)鐵(tie)(tie)芯中(zhong)產生磁(ci)通。打(da)開(kai)鐵(tie)(tie)芯和夾件(jian)的連接片(pian)(pian),用交流毫安(an)(an)(an)表(biao)(或萬用表(biao)的mA檔)的兩接線(xian)電筆,沿鐵(tie)(tie)軛(e)各行逐(zhu)點(dian)測量(liang),當mA表(biao)中(zhong)有(you)(you)電流值顯示(shi),說(shuo)明(ming)鐵(tie)(tie)芯接地(di)(di)正(zheng)常(chang),只有(you)(you)一點(dian)接地(di)(di);當毫安(an)(an)(an)中(zhong)指針指示(shi)為(wei)零(毫安(an)(an)(an)表(biao)中(zhong)無電流讀數),說(shuo)明(ming)被測處鐵(tie)(tie)芯疊(die)片(pian)(pian)為(wei)接地(di)(di)故(gu)障。
4.直流法測定多點(dian)接(jie)地故障。先將鐵芯與夾(jia)件的(de)連接(jie)片打開(kai),在(zai)鐵軛兩側的(de)硅(gui)鋼片上施(shi)加6V直流電(dian)壓,接(jie)著用直流電(dian)壓表(或(huo)(huo)萬用表直流電(dian)壓檔)依次測量各級鐵芯疊(die)片間的(de)電(dian)壓,當(dang)電(dian)壓表的(de)指針在(zai)零位,讀數(shu)為(wei)0,或(huo)(huo)指針指示反向,則可認為(wei)被(bei)測處是故障接(jie)地點(dian)。
四、鐵(tie)芯(xin)多點(dian)接地故障的排(pai)除方法
(一)變壓器不能停(ting)運時的(de)臨時排除方法(fa)
1.對(dui)有(you)外接(jie)地(di)(di)線(xian)(xian)的(de)變(bian)壓器,當發生多點(dian)接(jie)地(di)(di)故障,若測得故障電流較(jiao)大時(shi),先可臨(lin)時(shi)斷(duan)開地(di)(di)線(xian)(xian),使變(bian)壓器處于無接(jie)地(di)(di)(正常(chang)一點(dian)接(jie)地(di)(di))狀態下(xia)運行。采取此種措施應(ying)注意的(de)是(shi)要加強對(dui)運行的(de)變(bian)壓器的(de)監視,以防(fang)故障點(dian)臨(lin)時(shi)消失后使鐵芯出(chu)現懸浮電位。
2.當(dang)檢測和判(pan)定的(de)多點接地(di)故障(zhang)接地(di)不(bu)實,屬于不(bu)穩定型。可采取在工(gong)作(zuo)接地(di)線中(zhong)串入一(yi)滑線電(dian)(dian)阻,將(jiang)電(dian)(dian)流限制在1A以下(xia)。具體做(zuo)法是(shi)先(xian)將(jiang)正常工(gong)作(zuo)接地(di)線打開,分別(bie)用電(dian)(dian)壓(ya)表及電(dian)(dian)流表測出(chu)電(dian)(dian)壓(ya)及電(dian)(dian)流,根(gen)據歐姆定律求出(chu)電(dian)(dian)阻R,即R=U/I,從(cong)而來(lai)確定電(dian)(dian)阻容(rong)量的(de)大小;滑線電(dian)(dian)阻先(xian)取好后,將(jiang)其串接在工(gong)作(zuo)接地(di)線中(zhong)。
3.加(jia)強監視,可(ke)(ke)經(jing)常取油樣進行色譜分(fen)析,判定(ding)故(gu)障(zhang)點的產氣(qi)速(su)率(lv)大小,如產氣(qi)速(su)率(lv)緩慢,變壓器可(ke)(ke)繼(ji)續運行;若(ruo)產氣(qi)速(su)率(lv)較快,為防止(zhi)故(gu)障(zhang)擴大,應退出運行,組(zu)織檢修。
4.移接正(zheng)(zheng)常接地線(xian)位(wei)置,當多(duo)點接地故障點位(wei)置檢(jian)測(ce)中已(yi)確認,又無(wu)法處理,可采(cai)取將鐵芯的(de)正(zheng)(zheng)常工作接地片移至故障點同一位(wei)置,用以(yi)較大幅(fu)度地減(jian)少環(huan)流。
(二)變壓(ya)器停運后的修理(li)措施
1.對修后未將箱蓋上定位(wei)銷翻(fan)轉或(huo)除去,造(zao)成多點接(jie)地的,應(ying)將箱蓋上定位(wei)銷翻(fan)轉過(guo)來或(huo)除掉,使(shi)其(qi)不構成多點接(jie)地。除掉定位(wei)銷(或(huo)翻(fan)過(guo)來)后,應(ying)進一(yi)步(bu)檢查(cha)其(qi)它原因造(zao)成多點接(jie)地故障現象(xiang),如有應(ying)予以排除。
2.因夾件肢板(ban)距芯柱太近,使翅起的疊(die)片(pian)(pian)與其相碰。則應調整夾件肢板(ban)和(he)扳直翹起的疊(die)片(pian)(pian),使兩者間(jian)距離符(fu)合絕(jue)緣間(jian)隙標準。
3.由于(yu)鐵軛(e)螺(luo)桿襯(chen)套過長,應在檢修中(zhong)將其(qi)擰下,鋸去一段使(shi)其(qi)與(yu)疊(die)片(pian)不相(xiang)碰。
4.對于夾件墊腳與鐵軛(e)間的絕緣(yuan)紙板脫落(luo)或破損(sun)者,應接絕緣(yuan)規范要(yao)求(qiu),更換(huan)一定厚度的新紙板。
5.對于鐵軛螺桿(gan)絕緣管損壞(huai)而造(zao)成的多點(dian)接地,應及時更換(huan)新的絕緣管。
6.檢(jian)修或更換箱蓋上(shang)的溫度計座套(tao),使(shi)其與上(shang)夾件或鐵軛、旁住間距離符合規定要求,杜絕相碰造成多(duo)點接地。
7.清除油箱內油中或(huo)器身(shen)中落入的金屬異(yi)物,以消除由(you)其構成的接地故障。
8.消除(chu)油箱(xiang)底部及下夾件與鐵軛間木墊快上的油泥污物,對變壓器油進行真(zhen)空干燥處理,消除(chu)水分(fen)及潮氣,提高絕緣電阻(zu)值。
9.由于鐵芯疊片(pian)(pian)局部生(sheng)銹或(huo)絕(jue)緣(yuan)(yuan)漆皮、氧化(hua)膜層(ceng)脫(tuo)落,可拆下這部分(fen)疊片(pian)(pian),補涂硅鋼片(pian)(pian)漆,使片(pian)(pian)間有良好的絕(jue)緣(yuan)(yuan)層(ceng);當原(yuan)硅鋼片(pian)(pian)質量(liang)有問題(ti),表面(mian)不平(ping)度,凹凸不平(ping)坑密(mi)布,片(pian)(pian)間絕(jue)緣(yuan)(yuan)較差,又無法(fa)修(xiu)復時,只好更換這部分(fen)鐵芯疊片(pian)(pian)。