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)基本(ben)方法,主(zhu)要(yao)是檢查(cha)電(dian)容器(qi)外部是否(fou)有明顯損(sun)壞,是否(fou)有裂(lie)縫、鼓(gu)包、滲漏油的(de)情(qing)況。此外,也需(xu)要(yao)檢查(cha)鏈接(jie)部分是否(fou)有松動或腐蝕(shi)現象,接(jie)觸是否(fou)良好。
2、進行電路檢查
通過(guo)使用數字萬(wan)用表、LCR表等測(ce)試儀器,在斷開電(dian)容(rong)器電(dian)路(lu)的情況下,分(fen)別測(ce)量電(dian)容(rong)器兩端的電(dian)壓(ya)、電(dian)阻、電(dian)容(rong)等參數,以(yi)判斷電(dian)容(rong)器是否正常工作。
3、進行絕緣測試
絕緣(yuan)(yuan)測(ce)試(shi)是(shi)判(pan)斷電(dian)(dian)(dian)力電(dian)(dian)(dian)容器絕緣(yuan)(yuan)性(xing)能(neng)好壞的(de)(de)重要(yao)手段。可(ke)(ke)以使用絕緣(yuan)(yuan)電(dian)(dian)(dian)阻(zu)(zu)測(ce)試(shi)儀(yi)或(huo)萬(wan)用表的(de)(de)絕緣(yuan)(yuan)測(ce)試(shi)功能(neng),將電(dian)(dian)(dian)容器與(yu)地之間的(de)(de)絕緣(yuan)(yuan)電(dian)(dian)(dian)阻(zu)(zu)進行測(ce)試(shi)。通常要(yao)求(qiu)電(dian)(dian)(dian)容器的(de)(de)絕緣(yuan)(yuan)電(dian)(dian)(dian)阻(zu)(zu)應大于(yu)一定閾值,否則(ze)說明電(dian)(dian)(dian)容器絕緣(yuan)(yuan)性(xing)能(neng)差,可(ke)(ke)能(neng)存在(zai)故障。
4、進行容量測試
需要(yao)使用(yong)專(zhuan)用(yong)的(de)電(dian)容(rong)(rong)器(qi)容(rong)(rong)量(liang)(liang)測試設備或數字萬(wan)用(yong)表對(dui)電(dian)容(rong)(rong)器(qi)容(rong)(rong)量(liang)(liang)進(jin)行測試,把測試結果(guo)(guo)與電(dian)容(rong)(rong)器(qi)標定(ding)(ding)值進(jin)行比較(jiao),如果(guo)(guo)差(cha)異較(jiao)大,則(ze)可能(neng)存在電(dian)容(rong)(rong)器(qi)容(rong)(rong)量(liang)(liang)下降的(de)問(wen)題,如果(guo)(guo)電(dian)容(rong)(rong)容(rong)(rong)量(liang)(liang)下降到一定(ding)(ding)程度則(ze)代(dai)表電(dian)力(li)電(dian)容(rong)(rong)器(qi)失效。
5、進行運行溫度測試
電力電容器(qi)的(de)運行溫(wen)度(du)是否正常(chang)是判斷電容運行狀(zhuang)(zhuang)態的(de)重要指標之一,工(gong)作人員可(ke)(ke)以使用紅外測(ce)溫(wen)儀(yi)或(huo)接觸式溫(wen)度(du)計進行測(ce)試,測(ce)量(liang)電容器(qi)外殼表(biao)面的(de)溫(wen)度(du)。如果(guo)電容器(qi)表(biao)面溫(wen)度(du)異常(chang)高或(huo)異常(chang)低,則可(ke)(ke)能存在(zai)內部故障或(huo)不正常(chang)的(de)工(gong)作狀(zhuang)(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(li)電(dian)容器廠(chang)家生產(chan)工(gong)藝不良、加工(gong)粗(cu)糙,電(dian)力(li)電(dian)容器運(yun)行時會出現放電(dian)擊穿,從而引發一系列故障。
2、密封不良
由于廠家(jia)焊接(jie)原因(yin)、運輸或安裝不當,可能(neng)會造(zao)成電力電容器密封不良,從(cong)而(er)出現(xian)滲漏油故障,造(zao)成電力電容器損壞。
3、環境溫度太高
當運行環境溫度太高時(shi),電(dian)力電(dian)容器內部會溫升異常,導致電(dian)容器熱(re)擊(ji)穿,從(cong)而加速(su)絕緣介質老化,造成電(dian)力電(dian)容器損壞。
4、過電壓、過電流運行
長期(qi)過(guo)電壓、過(guo)電流運行,會(hui)導致(zhi)電力電容(rong)器內部(bu)擊穿放(fang)電,從(cong)而出現鼓肚損壞等故障(zhang)。
5、合閘涌流
當電(dian)(dian)(dian)(dian)(dian)(dian)力電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)器合(he)閘(zha)瞬間電(dian)(dian)(dian)(dian)(dian)(dian)壓為零時,涌(yong)(yong)流數值一(yi)切正常(chang);當電(dian)(dian)(dian)(dian)(dian)(dian)力電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)器合(he)閘(zha)瞬間電(dian)(dian)(dian)(dian)(dian)(dian)壓為較大時,合(he)閘(zha)涌(yong)(yong)流的(de)大小是(shi)幾十倍額(e)定(ding)電(dian)(dian)(dian)(dian)(dian)(dian)壓。這會給(gei)電(dian)(dian)(dian)(dian)(dian)(dian)力電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)器的(de)運行產生影響,甚至會導致電(dian)(dian)(dian)(dian)(dian)(dian)力電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)器損(sun)壞。
6、帶電荷合閘
帶電荷(he)合閘(zha)是明令禁(jin)止的(de)(de),因為帶電荷(he)合閘(zha)造(zao)成爆炸(zha)事故(gu)的(de)(de)發生,對企業的(de)(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(zhi)(zhi)到6%-9%范圍(wei),可限制(zhi)(zhi)合閘電流。
(2)分閘操作錢,可以(yi)將電抗器調制零,以(yi)降斷口恢復電壓,減少電弧重。
(3)進入(ru)穩定運(yun)行后,諧波(bo)很小時把電(dian)抗器(qi)的電(dian)感調制0,以便(bian)電(dian)力電(dian)容(rong)器(qi)組(zu)發揮比較高(gao)的補償效率,并式電(dian)力電(dian)容(rong)器(qi)組(zu)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)電壓變化率dUc/dt=0時投入,可使沖擊電流比較小。
(2)在晶閘(zha)管端電(dian)壓為0時投入,也可(ke)以使沖(chong)擊(ji)電(dian)流比較小(xiao)。
兩種方法選(xuan)擇一種就行,都(dou)可有效解決電力(li)電容(rong)器投入時產(chan)生的電流沖擊問題。
3、加裝避雷器抑制操作
加裝避雷器(qi)(qi)抑制(zhi)操作過電(dian)(dian)壓、過電(dian)(dian)流,建議采用限流電(dian)(dian)抗器(qi)(qi)串聯在電(dian)(dian)力(li)電(dian)(dian)容(rong)器(qi)(qi)組之前的接(jie)線方式,利用MOA接(jie)在電(dian)(dian)力(li)電(dian)(dian)容(rong)器(qi)(qi)進線端對電(dian)(dian)力(li)電(dian)(dian)容(rong)器(qi)(qi)組進行(xing)保(bao)護。
根據(ju)以(yi)上三種方(fang)法(fa),采取(qu)相應的(de)抑(yi)制(zhi)措施,有針對性的(de)進行解決。