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基本方(fang)法,主(zhu)要是(shi)(shi)檢查電(dian)容器(qi)外部(bu)是(shi)(shi)否(fou)(fou)有明顯(xian)損壞,是(shi)(shi)否(fou)(fou)有裂縫、鼓(gu)包、滲漏(lou)油的情況。此(ci)外,也需要檢查鏈接部(bu)分是(shi)(shi)否(fou)(fou)有松(song)動(dong)或(huo)腐蝕(shi)現(xian)象,接觸是(shi)(shi)否(fou)(fou)良好。
2、進行電路檢查
通過使用數字萬用表(biao)、LCR表(biao)等(deng)測試儀器(qi),在(zai)斷開電(dian)容(rong)器(qi)電(dian)路的(de)(de)情況(kuang)下,分(fen)別測量(liang)電(dian)容(rong)器(qi)兩端的(de)(de)電(dian)壓、電(dian)阻、電(dian)容(rong)等(deng)參數,以判斷電(dian)容(rong)器(qi)是否(fou)正(zheng)常工(gong)作。
3、進行絕緣測試
絕(jue)緣(yuan)測試(shi)(shi)是判斷(duan)電力(li)電容器(qi)絕(jue)緣(yuan)性能好(hao)壞的重要(yao)手(shou)段。可以使用絕(jue)緣(yuan)電阻測試(shi)(shi)儀或萬用表的絕(jue)緣(yuan)測試(shi)(shi)功能,將電容器(qi)與地之間的絕(jue)緣(yuan)電阻進行測試(shi)(shi)。通常要(yao)求(qiu)電容器(qi)的絕(jue)緣(yuan)電阻應大于一定閾值,否則說明電容器(qi)絕(jue)緣(yuan)性能差,可能存在故障。
4、進行容量測試
需要使用專用的電(dian)容(rong)(rong)(rong)(rong)器(qi)(qi)(qi)(qi)容(rong)(rong)(rong)(rong)量測試(shi)(shi)設備或數字萬用表對電(dian)容(rong)(rong)(rong)(rong)器(qi)(qi)(qi)(qi)容(rong)(rong)(rong)(rong)量進行測試(shi)(shi),把測試(shi)(shi)結果與電(dian)容(rong)(rong)(rong)(rong)器(qi)(qi)(qi)(qi)標定值進行比較(jiao),如果差異(yi)較(jiao)大,則可(ke)能存在電(dian)容(rong)(rong)(rong)(rong)器(qi)(qi)(qi)(qi)容(rong)(rong)(rong)(rong)量下(xia)降的問題,如果電(dian)容(rong)(rong)(rong)(rong)容(rong)(rong)(rong)(rong)量下(xia)降到(dao)一定程度則代表電(dian)力電(dian)容(rong)(rong)(rong)(rong)器(qi)(qi)(qi)(qi)失效。
5、進行運行溫度測試
電力(li)電容(rong)器(qi)的(de)(de)(de)運行溫度(du)是否正(zheng)常(chang)是判(pan)斷電容(rong)運行狀(zhuang)態的(de)(de)(de)重要指標之一,工(gong)作人員可以使用紅(hong)外(wai)測溫儀或(huo)(huo)接觸式溫度(du)計進行測試,測量電容(rong)器(qi)外(wai)殼(ke)表面(mian)的(de)(de)(de)溫度(du)。如(ru)果電容(rong)器(qi)表面(mian)溫度(du)異常(chang)高或(huo)(huo)異常(chang)低,則(ze)可能存在內部故障或(huo)(huo)不正(zheng)常(chang)的(de)(de)(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
如果電(dian)力電(dian)容(rong)器廠家(jia)生產工(gong)藝(yi)不良、加工(gong)粗(cu)糙,電(dian)力電(dian)容(rong)器運行時會出現放電(dian)擊穿,從而引(yin)發一系列故障。
2、密封不良
由于廠家焊接原(yuan)因(yin)、運輸(shu)或安裝(zhuang)不當,可(ke)能(neng)會造成電(dian)(dian)力電(dian)(dian)容(rong)器密(mi)封不良,從而出現滲(shen)漏油故障,造成電(dian)(dian)力電(dian)(dian)容(rong)器損(sun)壞。
3、環境溫度太高
當運行環(huan)境溫度(du)太(tai)高(gao)時(shi),電力(li)電容器內部(bu)會(hui)溫升異常,導致電容器熱擊穿,從而加速(su)絕(jue)緣介(jie)質老化,造成(cheng)電力(li)電容器損壞。
4、過電壓、過電流運行
長期過電壓、過電流運行,會導(dao)致(zhi)電力電容器內部擊穿放電,從而出現鼓肚損壞(huai)等故障。
5、合閘涌流
當電(dian)(dian)(dian)(dian)力(li)電(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)合(he)閘瞬(shun)間(jian)(jian)電(dian)(dian)(dian)(dian)壓(ya)為零時(shi),涌(yong)流數值(zhi)一(yi)切正常;當電(dian)(dian)(dian)(dian)力(li)電(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)合(he)閘瞬(shun)間(jian)(jian)電(dian)(dian)(dian)(dian)壓(ya)為較(jiao)大時(shi),合(he)閘涌(yong)流的(de)大小是幾十倍額(e)定電(dian)(dian)(dian)(dian)壓(ya)。這會給電(dian)(dian)(dian)(dian)力(li)電(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)的(de)運行產(chan)生影(ying)響,甚至(zhi)會導致電(dian)(dian)(dian)(dian)力(li)電(dian)(dian)(dian)(dian)容(rong)(rong)器(qi)(qi)損壞。
6、帶電荷合閘
帶(dai)電荷合閘是明令禁止(zhi)的(de)(de),因為帶(dai)電荷合閘造成爆炸事故的(de)(de)發生,對企業(ye)的(de)(de)影響(xiang)十分嚴重。
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)電抗器調制到6%-9%范(fan)圍(wei),可限制合閘電流。
(2)分閘操作錢,可(ke)以將電(dian)抗(kang)器調制零,以降斷口恢復電(dian)壓,減少電(dian)弧(hu)重(zhong)。
(3)進入穩定(ding)運行(xing)后(hou),諧波(bo)很小時(shi)把電(dian)抗器的電(dian)感調制(zhi)0,以便電(dian)力(li)電(dian)容器組發揮比較高的補償效率,并式電(dian)力(li)電(dian)容器組極間電(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(de)電(dian)壓變化率dUc/dt=0時投入(ru),可使沖擊電(dian)流比較小。
(2)在晶閘管端(duan)電壓為0時投入(ru),也可以(yi)使沖擊電流比較小(xiao)。
兩(liang)種方法選擇一種就行,都可有效(xiao)解決電(dian)(dian)力(li)電(dian)(dian)容器投(tou)入時產生(sheng)的電(dian)(dian)流(liu)沖擊問題。
3、加裝避雷器抑制操作
加裝避(bi)雷器(qi)抑制操(cao)作(zuo)過電(dian)(dian)壓(ya)、過電(dian)(dian)流,建議采用(yong)限流電(dian)(dian)抗器(qi)串聯在電(dian)(dian)力電(dian)(dian)容器(qi)組(zu)之前的接線方式,利用(yong)MOA接在電(dian)(dian)力電(dian)(dian)容器(qi)進線端對電(dian)(dian)力電(dian)(dian)容器(qi)組(zu)進行保護。
根據(ju)以上(shang)三種方(fang)法,采取相(xiang)應的抑制措施,有(you)針對性(xing)的進行解(jie)決(jue)。