一、電力電容器怎么測量好壞
1、進行外觀檢查
檢查外觀是檢測電力電容器好壞的(de)基(ji)本方法,主要是(shi)檢(jian)查電容器外部(bu)是(shi)否(fou)有(you)明(ming)顯損壞,是(shi)否(fou)有(you)裂縫、鼓包、滲(shen)漏(lou)油的(de)情(qing)況。此外,也(ye)需要檢(jian)查鏈(lian)接部(bu)分(fen)是(shi)否(fou)有(you)松動或腐蝕(shi)現象,接觸(chu)是(shi)否(fou)良(liang)好。
2、進行電路檢查
通過(guo)使用(yong)數字萬用(yong)表、LCR表等測試儀器(qi),在斷開(kai)電(dian)(dian)(dian)容(rong)器(qi)電(dian)(dian)(dian)路的情況下,分別(bie)測量電(dian)(dian)(dian)容(rong)器(qi)兩端(duan)的電(dian)(dian)(dian)壓、電(dian)(dian)(dian)阻、電(dian)(dian)(dian)容(rong)等參數,以判斷電(dian)(dian)(dian)容(rong)器(qi)是否正常工作。
3、進行絕緣測試
絕(jue)緣(yuan)(yuan)(yuan)測(ce)試(shi)是(shi)判(pan)斷電(dian)(dian)力電(dian)(dian)容器(qi)絕(jue)緣(yuan)(yuan)(yuan)性能(neng)好壞的重要手段。可以使用絕(jue)緣(yuan)(yuan)(yuan)電(dian)(dian)阻測(ce)試(shi)儀或萬用表的絕(jue)緣(yuan)(yuan)(yuan)測(ce)試(shi)功能(neng),將(jiang)電(dian)(dian)容器(qi)與地之間的絕(jue)緣(yuan)(yuan)(yuan)電(dian)(dian)阻進行測(ce)試(shi)。通常要求電(dian)(dian)容器(qi)的絕(jue)緣(yuan)(yuan)(yuan)電(dian)(dian)阻應大(da)于一定(ding)閾(yu)值(zhi),否則說明(ming)電(dian)(dian)容器(qi)絕(jue)緣(yuan)(yuan)(yuan)性能(neng)差(cha),可能(neng)存在故障。
4、進行容量測試
需要使用專用的(de)電(dian)容(rong)器(qi)(qi)容(rong)量測試設備或數字萬用表對電(dian)容(rong)器(qi)(qi)容(rong)量進行測試,把測試結果與電(dian)容(rong)器(qi)(qi)標定值進行比較(jiao),如果差(cha)異(yi)較(jiao)大,則(ze)可能(neng)存在電(dian)容(rong)器(qi)(qi)容(rong)量下降(jiang)(jiang)的(de)問(wen)題,如果電(dian)容(rong)容(rong)量下降(jiang)(jiang)到一定程度則(ze)代表電(dian)力電(dian)容(rong)器(qi)(qi)失效。
5、進行運行溫度測試
電(dian)(dian)力(li)電(dian)(dian)容(rong)(rong)器(qi)的(de)運行溫(wen)度(du)是否正常(chang)是判斷電(dian)(dian)容(rong)(rong)運行狀(zhuang)態的(de)重要指標(biao)之一,工(gong)作人員可以使(shi)用紅外測(ce)溫(wen)儀(yi)或(huo)接觸式(shi)溫(wen)度(du)計進行測(ce)試(shi),測(ce)量電(dian)(dian)容(rong)(rong)器(qi)外殼表面的(de)溫(wen)度(du)。如果電(dian)(dian)容(rong)(rong)器(qi)表面溫(wen)度(du)異常(chang)高(gao)或(huo)異常(chang)低(di),則可能存在(zai)內部故障或(huo)不(bu)正常(chang)的(de)工(gong)作狀(zhuang)態。
二、電力電容器損壞的原因
1、電力電容器質量差
如(ru)果電(dian)力電(dian)容(rong)器廠家(jia)生產工藝不良、加(jia)工粗糙,電(dian)力電(dian)容(rong)器運(yun)行時會出現放電(dian)擊穿,從而引發(fa)一系列(lie)故(gu)障。
2、密封不良
由于廠家焊接原因、運輸(shu)或安裝不當,可能會造(zao)成電(dian)力電(dian)容器(qi)密封不良,從而出現滲(shen)漏(lou)油故障,造(zao)成電(dian)力電(dian)容器(qi)損壞。
3、環境溫度太高
當運(yun)行環境(jing)溫度太高時(shi),電(dian)(dian)力(li)電(dian)(dian)容器內部會(hui)溫升(sheng)異常,導致電(dian)(dian)容器熱擊穿,從而加速絕(jue)緣介(jie)質老化,造(zao)成電(dian)(dian)力(li)電(dian)(dian)容器損壞。
4、過電壓、過電流運行
長期過(guo)電(dian)壓、過(guo)電(dian)流運行,會(hui)導致電(dian)力電(dian)容器內部擊穿放電(dian),從而(er)出現鼓肚損壞等故障。
5、合閘涌流
當(dang)電(dian)(dian)(dian)力(li)(li)電(dian)(dian)(dian)容(rong)器(qi)合閘瞬間(jian)電(dian)(dian)(dian)壓(ya)為(wei)零時,涌流數值一切正(zheng)常;當(dang)電(dian)(dian)(dian)力(li)(li)電(dian)(dian)(dian)容(rong)器(qi)合閘瞬間(jian)電(dian)(dian)(dian)壓(ya)為(wei)較大(da)時,合閘涌流的大(da)小是幾十倍(bei)額定電(dian)(dian)(dian)壓(ya)。這會給電(dian)(dian)(dian)力(li)(li)電(dian)(dian)(dian)容(rong)器(qi)的運行產生(sheng)影(ying)響(xiang),甚至會導致電(dian)(dian)(dian)力(li)(li)電(dian)(dian)(dian)容(rong)器(qi)損壞。
6、帶電荷合閘
帶電荷合閘是明(ming)令禁止的,因為(wei)帶電荷合閘造(zao)成爆炸事(shi)故的發(fa)生,對(dui)企業的影響十分(fen)嚴重。
三、電力電容器損壞抑制措施
1、配置可調電抗器,操作過電壓過電流以及諧波放大有很好的抑制作用
(1)將(jiang)電抗器(qi)調制(zhi)到6%-9%范圍,可限制(zhi)合閘(zha)電流。
(2)分(fen)閘操作錢,可(ke)以將電(dian)抗器調(diao)制零,以降斷口(kou)恢(hui)復電(dian)壓,減(jian)少電(dian)弧重。
(3)進入(ru)穩定(ding)運行后,諧波很小(xiao)時把(ba)電(dian)抗(kang)器的電(dian)感調制0,以便(bian)電(dian)力電(dian)容器組(zu)發揮比較高的補(bu)償效率,并(bing)式電(dian)力電(dian)容器組(zu)極(ji)間電(dian)壓比較低。
2、利用晶閘管投切電力電容器組
(1)在電力電容器的電壓變化率dUc/dt=0時(shi)投(tou)入,可使沖擊電流比(bi)較小。
(2)在晶閘管端(duan)電壓為0時投入,也可(ke)以使沖擊電流(liu)比(bi)較(jiao)小。
兩(liang)種方(fang)法(fa)選擇一種就行,都可有效解決電(dian)力電(dian)容器投入時產生的電(dian)流沖擊問題。
3、加裝避雷器抑制操作
加裝避雷器(qi)抑制操作過(guo)電(dian)壓、過(guo)電(dian)流,建(jian)議(yi)采用(yong)限流電(dian)抗器(qi)串聯在電(dian)力(li)電(dian)容(rong)(rong)器(qi)組之前的(de)接(jie)線(xian)方式(shi),利用(yong)MOA接(jie)在電(dian)力(li)電(dian)容(rong)(rong)器(qi)進線(xian)端對電(dian)力(li)電(dian)容(rong)(rong)器(qi)組進行保護。
根(gen)據以上三種(zhong)方法,采取相應的(de)抑制(zhi)措施,有針對(dui)性的(de)進行(xing)解決。