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法,主要(yao)是(shi)檢(jian)查電容(rong)器外(wai)部是(shi)否(fou)(fou)(fou)有(you)明顯損壞,是(shi)否(fou)(fou)(fou)有(you)裂(lie)縫、鼓包、滲漏油的情況。此外(wai),也需要(yao)檢(jian)查鏈接(jie)部分是(shi)否(fou)(fou)(fou)有(you)松(song)動或腐(fu)蝕現(xian)象,接(jie)觸是(shi)否(fou)(fou)(fou)良(liang)好。
2、進行電路檢查
通過(guo)使用(yong)(yong)數字(zi)萬用(yong)(yong)表、LCR表等測試儀(yi)器(qi),在斷開(kai)電(dian)容器(qi)電(dian)路的情況(kuang)下(xia),分別測量電(dian)容器(qi)兩端(duan)的電(dian)壓(ya)、電(dian)阻、電(dian)容等參數,以判(pan)斷電(dian)容器(qi)是否正常工作。
3、進行絕緣測試
絕(jue)緣(yuan)測試(shi)是判斷電(dian)(dian)(dian)力(li)電(dian)(dian)(dian)容器(qi)(qi)絕(jue)緣(yuan)性能(neng)(neng)(neng)好壞的(de)重要(yao)手段。可(ke)以使(shi)用絕(jue)緣(yuan)電(dian)(dian)(dian)阻(zu)測試(shi)儀或萬用表的(de)絕(jue)緣(yuan)測試(shi)功能(neng)(neng)(neng),將電(dian)(dian)(dian)容器(qi)(qi)與地(di)之(zhi)間(jian)的(de)絕(jue)緣(yuan)電(dian)(dian)(dian)阻(zu)進行測試(shi)。通常要(yao)求電(dian)(dian)(dian)容器(qi)(qi)的(de)絕(jue)緣(yuan)電(dian)(dian)(dian)阻(zu)應大于(yu)一(yi)定閾值,否(fou)則(ze)說明電(dian)(dian)(dian)容器(qi)(qi)絕(jue)緣(yuan)性能(neng)(neng)(neng)差(cha),可(ke)能(neng)(neng)(neng)存在(zai)故障。
4、進行容量測試
需要使用(yong)(yong)專用(yong)(yong)的電(dian)容(rong)(rong)(rong)(rong)器容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)測(ce)試(shi)設備或數字(zi)萬用(yong)(yong)表(biao)對電(dian)容(rong)(rong)(rong)(rong)器容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)進行測(ce)試(shi),把測(ce)試(shi)結果與電(dian)容(rong)(rong)(rong)(rong)器標(biao)定值(zhi)進行比較(jiao),如果差(cha)異較(jiao)大(da),則(ze)可能存在(zai)電(dian)容(rong)(rong)(rong)(rong)器容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)下(xia)降的問題,如果電(dian)容(rong)(rong)(rong)(rong)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)下(xia)降到一定程度(du)則(ze)代表(biao)電(dian)力電(dian)容(rong)(rong)(rong)(rong)器失效。
5、進行運行溫度測試
電(dian)力電(dian)容(rong)器的(de)(de)(de)運行溫(wen)度(du)是否正常是判斷(duan)電(dian)容(rong)運行狀態的(de)(de)(de)重要(yao)指標之一,工(gong)作人員可以使用紅(hong)外測溫(wen)儀或接觸式溫(wen)度(du)計進行測試(shi),測量電(dian)容(rong)器外殼(ke)表面(mian)的(de)(de)(de)溫(wen)度(du)。如果電(dian)容(rong)器表面(mian)溫(wen)度(du)異(yi)常高(gao)或異(yi)常低,則可能存在內部故障或不正常的(de)(de)(de)工(gong)作狀態。
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(chang)家(jia)生產工藝不良、加工粗糙,電(dian)力電(dian)容(rong)器運行時會出現放(fang)電(dian)擊(ji)穿,從(cong)而引發一系列故障。
2、密封不良
由于廠(chang)家焊接原(yuan)因、運(yun)輸或安(an)裝不(bu)當(dang),可能會造(zao)成(cheng)電(dian)力電(dian)容(rong)器(qi)密(mi)封不(bu)良(liang),從(cong)而出現滲漏油故障,造(zao)成(cheng)電(dian)力電(dian)容(rong)器(qi)損壞。
3、環境溫度太高
當運行環境溫度太高(gao)時,電(dian)力(li)電(dian)容(rong)器(qi)內(nei)部(bu)會溫升異常,導(dao)致電(dian)容(rong)器(qi)熱擊穿,從而加速絕緣介質老化,造成電(dian)力(li)電(dian)容(rong)器(qi)損壞。
4、過電壓、過電流運行
長期過電(dian)壓、過電(dian)流運行,會導致電(dian)力電(dian)容(rong)器(qi)內部擊(ji)穿放電(dian),從(cong)而(er)出現鼓(gu)肚(du)損壞等故障。
5、合閘涌流
當電力(li)(li)(li)電容(rong)器合閘瞬間電壓(ya)(ya)為零(ling)時,涌流(liu)數值一切正(zheng)常;當電力(li)(li)(li)電容(rong)器合閘瞬間電壓(ya)(ya)為較大(da)時,合閘涌流(liu)的(de)(de)大(da)小是幾十倍額定(ding)電壓(ya)(ya)。這會給電力(li)(li)(li)電容(rong)器的(de)(de)運行產(chan)生影響,甚(shen)至會導致電力(li)(li)(li)電容(rong)器損壞。
6、帶電荷合閘
帶(dai)電(dian)荷(he)合閘是明令禁止的(de),因為(wei)帶(dai)電(dian)荷(he)合閘造成爆(bao)炸(zha)事(shi)故的(de)發生,對企業的(de)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)將電抗器調制到6%-9%范圍,可限制合閘電流。
(2)分閘操(cao)作錢,可以將電抗器(qi)調制零,以降斷(duan)口恢復電壓,減少電弧重(zhong)。
(3)進入(ru)穩定運行后,諧(xie)波很小時把(ba)電(dian)抗(kang)器(qi)(qi)的電(dian)感調(diao)制0,以便(bian)電(dian)力電(dian)容器(qi)(qi)組發揮比較高(gao)的補償效率,并(bing)式電(dian)力電(dian)容器(qi)(qi)組極間電(dian)壓比較低。
2、利用晶閘管投切電力電容器組
(1)在電力電容器的電(dian)壓變化(hua)率(lv)dUc/dt=0時(shi)投(tou)入,可(ke)使沖擊電(dian)流(liu)比較(jiao)小(xiao)。
(2)在晶閘管端電(dian)壓為0時投入,也可以使沖擊電(dian)流比較小(xiao)。
兩種方法選擇(ze)一種就行,都可有效解決電(dian)(dian)(dian)力電(dian)(dian)(dian)容(rong)器(qi)投入時產生的(de)電(dian)(dian)(dian)流沖擊問題。
3、加裝避雷器抑制操作
加裝避雷器抑制操作過(guo)電(dian)(dian)(dian)壓、過(guo)電(dian)(dian)(dian)流(liu),建議采用(yong)限流(liu)電(dian)(dian)(dian)抗器串聯在電(dian)(dian)(dian)力電(dian)(dian)(dian)容器組之前的接線方式,利用(yong)MOA接在電(dian)(dian)(dian)力電(dian)(dian)(dian)容器進線端(duan)對電(dian)(dian)(dian)力電(dian)(dian)(dian)容器組進行保護(hu)。
根(gen)據以上三種方(fang)法,采(cai)取相應的抑(yi)制措施,有(you)針對性(xing)的進行(xing)解(jie)決(jue)。