一、電容器跳閘的原因分析
電容器組采用常用的星型接線方式,三相共體外殼接于同一鐵框架,框架接地。電容器內(nei)部結構為(wei)多個元件(jian)并聯的(de)四(si)串結構,并設置內(nei)熔(rong)(rong)(rong)(rong)絲(si)(si)保(bao)護,檢修人員(yuan)與廠(chang)家人員(yuan)對(dui)(dui)損(sun)壞的(de)電(dian)容(rong)器(qi)進行解剖,發現受損(sun)電(dian)容(rong)器(qi)的(de)A、B相(xiang)內(nei)熔(rong)(rong)(rong)(rong)絲(si)(si)均熔(rong)(rong)(rong)(rong)斷(duan)了兩根,外(wai)(wai)包(bao)封破裂,經(jing)過認真(zhen)分析,認為(wei)一(yi)(yi)相(xiang)熔(rong)(rong)(rong)(rong)絲(si)(si)熔(rong)(rong)(rong)(rong)斷(duan)兩根后,造成(cheng)外(wai)(wai)包(bao)封損(sun)傷(shang)(shang),在外(wai)(wai)包(bao)封受傷(shang)(shang)的(de)情(qing)況下,長(chang)期(qi)運行發展成(cheng)對(dui)(dui)殼(ke)(ke)(ke)擊(ji)穿,并發展成(cheng)單相(xiang)接地。由于單相(xiang)接地呈不穩(wen)定電(dian)弧接地,使(shi)健(jian)全相(xiang)產生(sheng)過電(dian)壓而另一(yi)(yi)相(xiang)也(ye)有兩熔(rong)(rong)(rong)(rong)絲(si)(si)熔(rong)(rong)(rong)(rong)斷(duan),外(wai)(wai)包(bao)封受傷(shang)(shang)致使(shi)在過電(dian)壓作用下發展成(cheng)對(dui)(dui)殼(ke)(ke)(ke)擊(ji)穿,由此形成(cheng)相(xiang)間短路(lu),盡管保(bao)護可靠動作,但巨大的(de)短路(lu)電(dian)流產生(sheng)的(de)熱效應,仍(reng)對(dui)(dui)電(dian)容(rong)器(qi)造成(cheng)一(yi)(yi)定程度(du)的(de)損(sun)傷(shang)(shang),使(shi)電(dian)容(rong)器(qi)外(wai)(wai)殼(ke)(ke)(ke)嚴重變(bian)形。
另外由于(yu)電(dian)(dian)(dian)網(wang)(wang)中(zhong)存在大量(liang)的(de)(de)(de)(de)非線(xian)性負荷(he),使(shi)得電(dian)(dian)(dian)網(wang)(wang)中(zhong)諧波(bo)(bo)占有一(yi)(yi)定含量(liang)。110kV張河變電(dian)(dian)(dian)站除擔(dan)任城郊居民用(yong)電(dian)(dian)(dian)外,主要(yao)擔(dan)任工(gong)業供(gong)電(dian)(dian)(dian),除幾條10kV工(gong)業專線(xian)外,其他10kV線(xian)路(lu)上還有一(yi)(yi)些小型化工(gong)廠、鑄造(zao)廠等工(gong)業用(yong)戶(hu),這些用(yong)戶(hu)都(dou)可能(neng)(neng)產生諧波(bo)(bo)。盡管每戶(hu)產生的(de)(de)(de)(de)諧波(bo)(bo)很少,但可以(yi)匯(hui)集成(cheng)較大的(de)(de)(de)(de)諧波(bo)(bo)電(dian)(dian)(dian)流(liu)饋入電(dian)(dian)(dian)網(wang)(wang),使(shi)電(dian)(dian)(dian)網(wang)(wang)的(de)(de)(de)(de)諧波(bo)(bo)水平升高(gao),影響電(dian)(dian)(dian)網(wang)(wang)設備的(de)(de)(de)(de)安全(quan)運行。由于(yu)此(ci)變電(dian)(dian)(dian)站的(de)(de)(de)(de)無(wu)功(gong)補償裝置(zhi),配置(zhi)電(dian)(dian)(dian)抗率(lv)為6的(de)(de)(de)(de)串聯(lian)電(dian)(dian)(dian)抗器(qi)(qi)(qi),6的(de)(de)(de)(de)電(dian)(dian)(dian)抗率(lv)雖(sui)然能(neng)(neng)對5次及以(yi)上諧波(bo)(bo)有抑制作用(yong),但在3次諧波(bo)(bo)下使(shi)串聯(lian)電(dian)(dian)(dian)抗器(qi)(qi)(qi)與補償電(dian)(dian)(dian)容(rong)器(qi)(qi)(qi)的(de)(de)(de)(de)阻(zu)抗成(cheng)容(rong)性,出現(xian)諧波(bo)(bo)電(dian)(dian)(dian)流(liu)放大現(xian)象,使(shi)電(dian)(dian)(dian)容(rong)器(qi)(qi)(qi)過負荷(he)。盡管母(mu)線(xian)上以(yi)5次諧波(bo)(bo)為主,3次諧波(bo)(bo)含量(liang)不是很高(gao),而(er)(er)裝設電(dian)(dian)(dian)容(rong)器(qi)(qi)(qi)后,容(rong)性阻(zu)抗將原有的(de)(de)(de)(de)3次諧波(bo)(bo)含量(liang)放大,可能(neng)(neng)造(zao)成(cheng)內熔(rong)(rong)絲熔(rong)(rong)斷(duan)(duan)。由于(yu)總(zong)(zong)保護(hu)按(an)四組電(dian)(dian)(dian)容(rong)器(qi)(qi)(qi)額定電(dian)(dian)(dian)流(liu)的(de)(de)(de)(de)1.3倍整定,而(er)(er)4組電(dian)(dian)(dian)容(rong)器(qi)(qi)(qi)全(quan)部投入的(de)(de)(de)(de)情況(kuang)極少。當某一(yi)(yi)段時間內諧波(bo)(bo)含量(liang)偏高(gao)時,總(zong)(zong)過流(liu)保護(hu)不能(neng)(neng)動作,造(zao)成(cheng)某相內熔(rong)(rong)絲熔(rong)(rong)斷(duan)(duan),而(er)(er)內熔(rong)(rong)絲熔(rong)(rong)斷(duan)(duan)后不能(neng)(neng)被及時發現(xian),導(dao)致事故擴(kuo)大,造(zao)成(cheng)速斷(duan)(duan)跳閘。
從保(bao)(bao)(bao)護配(pei)置來看,電(dian)容(rong)器(qi)內部故(gu)障的保(bao)(bao)(bao)護只設(she)置內熔(rong)絲保(bao)(bao)(bao)護,而并未設(she)置導致事(shi)(shi)故(gu)擴大的后(hou)備保(bao)(bao)(bao)護——不(bu)平衡電(dian)壓保(bao)(bao)(bao)護,使內熔(rong)絲熔(rong)斷后(hou)不(bu)能及時發現,造成速斷跳閘(zha)事(shi)(shi)故(gu),因(yin)此,保(bao)(bao)(bao)護配(pei)置不(bu)完善是(shi)造成電(dian)容(rong)器(qi)事(shi)(shi)故(gu)擴大的主要原(yuan)因(yin)。
另外,不(bu)定(ding)期(qi)測(ce)量(liang)(liang)(liang)電(dian)容(rong)(rong)量(liang)(liang)(liang)也是造成(cheng)事(shi)故(gu)(gu)擴(kuo)(kuo)大(da)的(de)(de)(de)原因之一(yi)。由于電(dian)容(rong)(rong)器內(nei)部(bu)裝置最直接(jie)的(de)(de)(de)反應是電(dian)容(rong)(rong)量(liang)(liang)(liang)的(de)(de)(de)變化,而(er)電(dian)容(rong)(rong)量(liang)(liang)(liang)測(ce)量(liang)(liang)(liang)手(shou)段落后,進行(xing)電(dian)容(rong)(rong)器電(dian)容(rong)(rong)量(liang)(liang)(liang)的(de)(de)(de)測(ce)量(liang)(liang)(liang)時,需采用拆(chai)除(chu)連接(jie)線的(de)(de)(de)測(ce)量(liang)(liang)(liang)方(fang)法(fa),不(bu)僅(jin)測(ce)量(liang)(liang)(liang)麻煩而(er)且可能因拆(chai)裝連接(jie)線導(dao)致套管受力而(er)發(fa)生套管漏油的(de)(de)(de)故(gu)(gu)障。因此,自投入運(yun)行(xing)以來(lai)檢修人員從未(wei)進行(xing)過(guo)電(dian)容(rong)(rong)量(liang)(liang)(liang)測(ce)量(liang)(liang)(liang),而(er)又未(wei)設(she)置反應電(dian)容(rong)(rong)器內(nei)部(bu)故(gu)(gu)障的(de)(de)(de)保護,當內(nei)部(bu)個別內(nei)熔(rong)絲熔(rong)斷時,無法(fa)及時發(fa)現,造成(cheng)事(shi)故(gu)(gu)擴(kuo)(kuo)大(da)。
二、電容器的常見故障和處理
(一)滲(漏)油
問題:
對于(yu)電容(rong)器來說(shuo),滲(shen)漏(lou)油就(jiu)如同家常便飯(fan)一般,造(zao)成的(de)原因也是相當多(duo)方(fang)多(duo)面的(de),主(zhu)要有(you)以(yi)下幾點:
1、由于搬運(yun)方法(fa)不當,或提拿瓷套管(guan)致使其法(fa)蘭焊接處(chu)產生裂(lie)縫(feng)。
2、接(jie)線時(shi),因擰螺絲用力過大造成瓷套(tao)焊接(jie)處損傷。
3、產品(pin)制造(zao)過程中(zhong)存在的一些缺陷,均可能造(zao)成電(dian)容器出現滲(shen)、漏油現象。
4、電(dian)容(rong)器投入(ru)運行后,由于溫度變化劇烈,內部壓(ya)力增(zeng)加則會(hui)使滲、漏油現象更加嚴重。
5、由(you)于運行維護不當,電(dian)容(rong)(rong)器(qi)長期運行缺乏維修導致外殼漆層剝落,鐵(tie)皮銹(xiu)蝕(shi),也是造成運行中電(dian)容(rong)(rong)器(qi)滲(shen)、漏(lou)油的一個原因。
雖然比較常(chang)見,但是可不(bu)能忽(hu)略哦,有時(shi)候一個小(xiao)小(xiao)的毛病就容易造成大問題。電(dian)容器滲、漏油的后果是使浸漬劑減少,元件上(shang)部容易受潮并擊穿而使電(dian)容器損壞。所以,必(bi)須要進行及時(shi)的處理。
解決:
1、安裝電(dian)容器時(shi),每臺電(dian)容器的接線(xian)(xian)最(zui)好采(cai)用單獨的軟線(xian)(xian)與(yu)母線(xian)(xian)相連(lian),不要采(cai)用硬(ying)母線(xian)(xian)連(lian)接,以防止裝配應力(li)造成電(dian)容器套(tao)管損壞,破壞密封而(er)引(yin)起(qi)漏油。
2、搬運電容器(qi)時應直(zhi)立放置(zhi),嚴禁搬拿套(tao)管;接(jie)線時,擰螺絲(si)不能(neng)用力過大并要注意保護好(hao)套(tao)管。
3、電容器箱(xiang)殼和套(tao)管焊縫(feng)處(chu)(chu)滲(shen)(shen)油,可對滲(shen)(shen)、漏處(chu)(chu)進行除(chu)銹,然后用錫釬焊料修補,修補套(tao)管焊縫(feng)處(chu)(chu)時應注意烙鐵不能過熱以免銀層脫落,修補后進行涂漆。滲(shen)(shen)、漏油嚴重的要更換電容器。
(二)電容器外殼變形
問題:
由(you)于(yu)電(dian)(dian)容器(qi)(qi)內(nei)部介(jie)質在(zai)高壓電(dian)(dian)場(chang)作用下發(fa)生(sheng)游離,使介(jie)質分解(jie)而析(xi)出(chu)氣體(ti),或(huo)(huo)者由(you)于(yu)部分元件擊穿,電(dian)(dian)容器(qi)(qi)電(dian)(dian)極(ji)對外殼(ke)接地放電(dian)(dian)等原因均會使介(jie)質析(xi)出(chu)氣體(ti)。密封的(de)外殼(ke)中這些氣體(ti)將引起內(nei)部壓力(li)的(de)增(zeng)加(jia),因而將引起外殼(ke)膨脹變(bian)形。所以,電(dian)(dian)容器(qi)(qi)外殼(ke)變(bian)形,是電(dian)(dian)容器(qi)(qi)發(fa)生(sheng)故障(zhang)(zhang)或(huo)(huo)故障(zhang)(zhang)前的(de)征兆(zhao)。
解決:
經(jing)常對(dui)運行的(de)電容(rong)器組進行外觀(guan)檢查(cha)(cha)(cha),如發現電容(rong)器外殼(ke)膨脹(zhang)變(bian)形應(ying)及時采取(qu)措(cuo)施(shi)(shi),膨脹(zhang)嚴(yan)(yan)重者(100Kvar以(yi)下(xia)每(mei)面膨脹(zhang)量應(ying)不(bu)大于10mm;100Kvar及以(yi)上(shang)每(mei)面膨脹(zhang)量就不(bu)大于20mm)應(ying)立即(ji)停止(zhi)使用,并查(cha)(cha)(cha)明原因,更換電容(rong)器。外殼(ke)膨脹(zhang)不(bu)嚴(yan)(yan)重的(de)要(yao)采取(qu)通風措(cuo)施(shi)(shi),加強運行檢查(cha)(cha)(cha)工(gong)作(zuo)。
(三)保護裝置動作
問題:
1、由于電(dian)容器組(zu)(zu)三相電(dian)容量不平衡(heng)(heng),造成三相電(dian)流不平衡(heng)(heng),使(shi)電(dian)容器組(zu)(zu)保護(hu)裝置動作跳開電(dian)容器組(zu)(zu)斷路器。
2、對于裝(zhuang)有(you)熔(rong)斷器(qi)保護裝(zhuang)置(zhi)的電(dian)容(rong)器(qi),因電(dian)容(rong)器(qi)內部異(yi)常、電(dian)容(rong)量(liang)變化、極對外殼接地、涌流過大(da)和過電(dian)壓等(deng)情況,使熔(rong)斷器(qi)熔(rong)絲熔(rong)斷。
3、運行操作不當(dang),致使電容器運行電壓超過(guo)規定(ding)值,使保護裝(zhuang)置動作跳開斷路器。
解決:
1、定期測量電(dian)容(rong)器電(dian)容(rong)值,電(dian)容(rong)值偏差不超過額(e)定值的(de)(de)-5%~+10%范(fan)圍,電(dian)容(rong)值不應小于出廠(chang)值的(de)(de)95%。
2、電(dian)容器組安裝之(zhi)前,要分配一次電(dian)容量(liang),使其三(san)相容量(liang)平(ping)衡,其誤(wu)差(cha)不應超(chao)過(guo)一相總容量(liang)的5%;當裝有(you)繼(ji)電(dian)保(bao)護裝置(zhi)時還應滿足運行時平(ping)衡電(dian)流誤(wu)差(cha)不超(chao)過(guo)繼(ji)電(dian)保(bao)護動作電(dian)流的要求(qiu);保(bao)護裝置(zhi)動作后,應測(ce)量(liang)電(dian)容器極對外殼(ke)絕緣電(dian)阻不低(di)于(yu)2000MΩ。
3、為(wei)了限制(zhi)涌流和高(gao)次諧波的(de)流入,電容器組應加(jia)裝串聯電抗器。
4、電(dian)(dian)容(rong)(rong)器(qi)(qi)應(ying)在額定(ding)電(dian)(dian)壓(ya)(ya)下(xia)使用,如(ru)電(dian)(dian)網上電(dian)(dian)壓(ya)(ya)過(guo)低,則電(dian)(dian)容(rong)(rong)器(qi)(qi)達(da)不到額定(ding)出力(li),長期過(guo)電(dian)(dian)壓(ya)(ya)運行使電(dian)(dian)容(rong)(rong)器(qi)(qi)發熱,加速絕緣老化,容(rong)(rong)易造成(cheng)電(dian)(dian)容(rong)(rong)器(qi)(qi)損壞。根據規定(ding),當電(dian)(dian)網電(dian)(dian)壓(ya)(ya)長期超過(guo)電(dian)(dian)容(rong)(rong)器(qi)(qi)額定(ding)電(dian)(dian)壓(ya)(ya)10%時,應(ying)將電(dian)(dian)容(rong)(rong)器(qi)(qi)退出運行。
5、采用熔(rong)(rong)(rong)斷(duan)器(qi)作電容器(qi)保護時,熔(rong)(rong)(rong)斷(duan)器(qi)的(de)選擇要適當,一般(ban)熔(rong)(rong)(rong)體的(de)額(e)定電流(liu)不應大于(yu)電容器(qi)額(e)定電流(liu)的(de)1.3倍。
6、測(ce)量電容器極對(dui)外(wai)殼絕(jue)緣電阻應不(bu)低于2000MΩ。
(四)電容器瓷套表面閃絡放電
問題:
電容器(qi)在運行中,由(you)于缺乏清掃和維護,其瓷(ci)絕緣(yuan)表面(mian)(mian)臟(zang)污(wu),臟(zang)污(wu)物吸附水分后,使(shi)瓷(ci)套(tao)(tao)絕緣(yuan)降低,表面(mian)(mian)泄漏電流增(zeng)大,造(zao)(zao)(zao)成瓷(ci)套(tao)(tao)表面(mian)(mian)閃絡放電。另外,電容器(qi)瓷(ci)套(tao)(tao)表面(mian)(mian)臟(zang)污(wu),在系統某種(zhong)過電壓的作用(yong)下,造(zao)(zao)(zao)成瓷(ci)套(tao)(tao)表面(mian)(mian)閃絡放電。閃絡放電的結(jie)果,導致瓷(ci)套(tao)(tao)表面(mian)(mian)瓷(ci)質損(sun)壞,可能造(zao)(zao)(zao)成瓷(ci)套(tao)(tao)絕緣(yuan)擊(ji)穿(chuan)斷路器(qi)跳(tiao)閘事(shi)故。
解決:
運行中的電容器組應(ying)定期檢查(cha)、清掃;按防(fang)污等級(ji)采取(qu)相應(ying)防(fang)污措施(shi),在污穢嚴重地區(qu),電容器不宜安裝在室外。
(五)電容器爆炸
問題:
運行中電容器(qi)爆炸是(shi)一種惡性事故,一般在內部元件發生極(ji)間或對外(wai)殼絕緣擊穿時,與之并聯的其(qi)他電容器(qi)將對該(gai)電容器(qi)釋放很大的能量,可能會使(shi)電容器(qi)爆炸以致(zhi)引(yin)起(qi)火災。其(qi)原因(yin)有:
1、電容器內部元件(jian)擊穿:主要是(shi)由(you)于制造工藝不良(liang)所引(yin)起。
2、電容(rong)(rong)器(qi)(qi)外(wai)殼絕(jue)緣(yuan)的損(sun)(sun)壞:電容(rong)(rong)器(qi)(qi)高壓側(ce)引出線由薄銅片制成,如果制造工藝不(bu)良,邊緣(yuan)不(bu)平有毛(mao)刺或嚴重彎折,其尖(jian)端(duan)容(rong)(rong)量產生電暈,電暈會使(shi)(shi)油分解、箱殼膨脹、油面下降而造成擊穿(chuan)。另外(wai),在封(feng)蓋(gai)時轉角處燒(shao)焊(han)時間(jian)過長,將內(nei)部絕(jue)緣(yuan)燒(shao)傷并產生油污(wu)和氣體使(shi)(shi)擊穿(chuan)電壓大(da)大(da)下降而損(sun)(sun)壞。
3、密封不(bu)良和漏(lou)油:由于裝配(pei)套(tao)管密封不(bu)良,潮氣進入內(nei)部(bu),使絕緣電阻(zu)降低;或因漏(lou)油使油面(mian)下降,導致極(ji)對殼放電或元件擊穿(chuan)。
4、鼓(gu)(gu)肚和內部游離:主要(yao)是由(you)于內部產(chan)生(sheng)電(dian)(dian)暈、擊穿放(fang)電(dian)(dian)和嚴重(zhong)游離時(shi),電(dian)(dian)容器在過電(dian)(dian)壓(ya)的作用下,會使元件起(qi)始游離電(dian)(dian)壓(ya)降低到工作電(dian)(dian)場(chang)強度之下,由(you)此引(yin)起(qi)一系(xi)列物理、化(hua)學、電(dian)(dian)氣(qi)效應,使絕緣加速老化(hua)、分解(jie),產(chan)生(sheng)氣(qi)體。形成惡(e)性循環,致使箱殼壓(ya)力(li)增大(da),造成箱壁外鼓(gu)(gu)以(yi)致爆炸(zha)。
5、帶(dai)電(dian)(dian)(dian)合(he)閘引起(qi)電(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)(qi)(qi)爆(bao)(bao)炸:任何額(e)定(ding)電(dian)(dian)(dian)壓的(de)(de)電(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)(qi)(qi)組均(jun)禁止帶(dai)電(dian)(dian)(dian)合(he)閘。電(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)(qi)(qi)組每次(ci)重新合(he)閘,必須在(zai)開(kai)關斷開(kai)的(de)(de)情況(kuang)下將(jiang)電(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)(qi)(qi)放電(dian)(dian)(dian)3min后才能進行。否則合(he)閘瞬(shun)間的(de)(de)電(dian)(dian)(dian)壓極性可(ke)能與電(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)(qi)(qi)上殘留電(dian)(dian)(dian)荷的(de)(de)極性相反而引起(qi)爆(bao)(bao)炸。為(wei)此一般(ban)規定(ding)容(rong)(rong)量(liang)在(zai)160Kvar以上的(de)(de)電(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)(qi)(qi)組,應裝(zhuang)(zhuang)設無電(dian)(dian)(dian)壓時自動(dong)跳(tiao)閘裝(zhuang)(zhuang)置(zhi),并規定(ding)電(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)(qi)(qi)組的(de)(de)開(kai)關不允許裝(zhuang)(zhuang)設自動(dong)重合(he)閘。
此外(wai),還可(ke)能(neng)由于溫度(du)過(guo)高、通(tong)風不(bu)良(liang)、運行電壓過(guo)高、電壓諧波分量過(guo)大或(huo)操作過(guo)電壓等而引(yin)起爆炸。
解決:
電(dian)(dian)容(rong)(rong)器(qi)(qi)的(de)(de)投為了防止電(dian)(dian)容(rong)(rong)器(qi)(qi)發生爆裂(lie)(lie)(lie)事故(gu),除要(yao)求加強運(yun)行中(zhong)的(de)(de)巡視檢查外,最主要(yao)的(de)(de)是安裝電(dian)(dian)容(rong)(rong)器(qi)(qi)的(de)(de)保(bao)護裝置,將(jiang)電(dian)(dian)容(rong)(rong)器(qi)(qi)釀成爆裂(lie)(lie)(lie)事故(gu)前及時(shi)切除。在(zai)運(yun)行時(shi),如發現(xian)電(dian)(dian)容(rong)(rong)器(qi)(qi)發出“咕(gu)咕(gu)”聲,是電(dian)(dian)容(rong)(rong)器(qi)(qi)內(nei)部絕(jue)緣(yuan)崩潰的(de)(de)先兆,因此(ci)應(ying)停止運(yun)行,查找故(gu)障電(dian)(dian)容(rong)(rong)器(qi)(qi)。電(dian)(dian)容(rong)(rong)器(qi)(qi)發生爆裂(lie)(lie)(lie)后,應(ying)更換電(dian)(dian)容(rong)(rong)器(qi)(qi)。
(六)端子安裝不牢
問題:
電(dian)容(rong)器接線(xian)(xian)端子安裝不牢,在電(dian)流(liu)通(tong)過導線(xian)(xian)時(shi),將引起接觸電(dian)阻增加,有時(shi)會發(fa)(fa)出(chu)(chu)“吱吱”的放(fang)電(dian)聲,使(shi)端子發(fa)(fa)熱(re)變形,并發(fa)(fa)出(chu)(chu)放(fang)電(dian)聲,嚴(yan)重時(shi)將端子燒(shao)紅熔化。
解決:
用(yong)紅外熱像儀測(ce)量端(duan)(duan)子及器身溫度。如端(duan)(duan)子表面有過發熱氧(yang)化現象(xiang),應(ying)打磨端(duan)(duan)子接(jie)觸面,涂上導電脂后擰緊螺絲(si)。如端(duan)(duan)子發熱嚴重或熔化,應(ying)更換接(jie)線端(duan)(duan)。
(七)電容器溫度升高
問題:
主要原因是電(dian)(dian)(dian)容(rong)器長時間過(guo)電(dian)(dian)(dian)壓(ya)運行(xing)、附近的整流裝(zhuang)置產生的高(gao)(gao)次(ci)諧波流入(ru)使(shi)電(dian)(dian)(dian)容(rong)器過(guo)電(dian)(dian)(dian)流、電(dian)(dian)(dian)容(rong)器選擇不(bu)當(dang)、油(you)量過(guo)少和通風(feng)條件差等。另(ling)外(wai),由于電(dian)(dian)(dian)容(rong)器長期運行(xing)后(hou)介質(zhi)老化(hua),介質(zhi)損耗不(bu)斷增加都(dou)可(ke)能導致電(dian)(dian)(dian)容(rong)器溫升(sheng)過(guo)高(gao)(gao)。電(dian)(dian)(dian)容(rong)器溫度升(sheng)高(gao)(gao)將影響電(dian)(dian)(dian)容(rong)器的壽(shou)命并導致電(dian)(dian)(dian)容(rong)器絕緣擊穿而損壞(huai)。
解決:
運行中應嚴格監視和控制電容器室的環境溫度,為了便于監視運行中的環境溫度,應選擇散熱條件最差處(電容器高度的三分之二處)裝設溫度計,要使溫度計的裝設位置便于觀察。為了監視電容器的外殼(ke)溫度,可(ke)在電容器(qi)(qi)外殼(ke)上(銘牌附近)粘貼示溫蠟片。如(ru)室溫過高,應采取(qu)(qu)必要的通風(feng)、降溫措施,如(ru)果采取(qu)(qu)措施后仍然不能滿(man)足室溫控制在40℃以(yi)下的要求時,應立即(ji)停止運行。如(ru)系電容器(qi)(qi)問題應更(geng)換電容器(qi)(qi)。