
變壓器在運行中,鐵芯及固定鐵芯、繞組的金屬結構、零件、部(bu)件(jian)等(deng)均(jun)處(chu)在(zai)強(qiang)電(dian)場(chang)中(zhong),在(zai)電(dian)場(chang)的(de)作(zuo)用(yong)下(xia),它(ta)們(men)具(ju)有(you)較(jiao)高(gao)的(de)對(dui)地(di)電(dian)位(wei)。如(ru)果(guo)鐵(tie)芯(xin)不(bu)接(jie)地(di),它(ta)與(yu)接(jie)地(di)的(de)夾(jia)件(jian)及(ji)油(you)箱(xiang)等(deng)之(zhi)間(jian)就(jiu)會(hui)產(chan)生(sheng)電(dian)位(wei)差(cha),在(zai)電(dian)位(wei)差(cha)的(de)作(zuo)用(yong)下(xia),可(ke)能(neng)會(hui)產(chan)生(sheng)斷(duan)續(xu)的(de)放(fang)電(dian)現(xian)象(xiang)。
除此之外,變壓器在運行中,繞組的周圍具有較強的磁場,鐵芯、金屬結構、零件、部件等都處在非均勻的磁場中,它們與繞組的距離各不相等,所以,各金屬結構、零件、bujiandengshoucichangganyingchanshengdediandongshidaxiaoyegebuxiangdeng,bicizhijianyecunzaizhedianweicha。dianweichasuiranbuda,danyenengjichuanhenxiaodejueyuanjianxi,yineryekenenghuiyinqichixuxingdeweiliangfangdianxianxiang。
wulunshiyouyudianweichadezuoyongkenengchanshengdeduanxufangdianxianxiang,haishikenengjichuanhenxiaodejueyuanjianxiyinqidechixuxingweiliangfangdianxianxiang,doushibunengyunxude,erqieyaojianzhazhexieduanxufangdiandebuweishifeichangkunnande。
解決的有效辦法是,將鐵芯及固定鐵芯、繞組的金屬結構、零件、bujiandengkekaojiedi,shitamenyuyouxiangdengtongchuyudadidianwei。bianyaqidetiexinjiedishiyidianjiedi,erqiezhinengshiyidianjiedi。yinweitiexindeguigangpianxianghuzhijianshijueyuande,zheshiweilefangzhichanshengjiaodadewoliu,yinci,qiebukejiangsuoyoudeguigangpiandoujiedihuoduodianjiedi,fouze,jiangzaochengjiaodadewoliuershitiexinyanzhongfare。
變bian壓ya器qi的de鐵tie芯xin接jie地di,通tong常chang是shi將jiang鐵tie芯xin的de任ren意yi一yi片pian矽gui鋼gang片pian接jie地di。因yin為wei矽gui鋼gang片pian之zhi間jian雖sui然ran絕jue緣yuan,但dan其qi絕jue緣yuan電dian阻zu數shu值zhi是shi很hen小xiao的de,不bu均jun勻yun的de強qiang電dian場chang和he強qiang磁ci場chang,可ke以yi使shi矽gui鋼gang片pian中zhong感gan應ying的de高gao壓ya電dian荷he通tong過guo矽gui鋼gang片pian從cong接jie地di處chu流liu向xiang大da地di,但dan卻que能neng阻zu止zhi渦wo流liu從cong一yi片pian流liu向xiang另ling一yi片pian。所suo以yi,隻zhi要yao將jiang鐵tie芯xin的de任ren意yi一yi片pian矽gui鋼gang片pian接jie地di,那na麼me,就jiu等deng於yu將jiang整zheng個ge鐵tie芯xin都dou接jie地di了le。
需要注意的是:變壓器的鐵芯必須是一點接地,不能是兩點接地,更不能多點接地,因為多點接地是變壓器的常見故障之一。■ 變壓器鐵芯為什麼不能多點接地。
yinweibianyaqitiexindiepianzhisuoyizhinengyidianjiedi,shiyinweijiaruyouliangdianyishangjiedi,zheyangjiedidianzhijianjiukenengxingchenghuilu。dangzhucidaochuanguocibihehuiludeshihou,jiuhuizaiqizhongchanshenglexunhuandianliu,zaochengneibuguoreyinfashigu。shaorongdejubutiexinhuixingchengtiexinpianjiandeduanluguzhang,shidetiesunbianda,yanzhonghuiyingxiangbianyaqidexingnenghezhengchanggongzuo,zhinenggenghuantiexinguigangpianjiayixiufu,yincibianyaqibuyunxuduodianjiedizhinengyouqiezhiyouyidianjiedi。
變(bian)壓(ya)器(qi)在(zai)運(yun)行(xing)過(guo)程(cheng)中(zhong),其(qi)鐵(tie)芯(xin)以(yi)及(ji)夾(jia)件(jian)等(deng)金(jin)屬(shu)部(bu)件(jian)均(jun)處(chu)在(zai)強(qiang)電(dian)場(chang)之(zhi)中(zhong),因(yin)為(wei)靜(jing)電(dian)感(gan)應(ying)會(hui)在(zai)鐵(tie)芯(xin)及(ji)金(jin)屬(shu)部(bu)件(jian)上(shang)產(chan)生(sheng)懸(xuan)浮(fu)電(dian)位(wei),而(er)這(zhe)一(yi)電(dian)位(wei)會(hui)對(dui)地(di)放(fang)電(dian),這(zhe)當(dang)然(ran)是(shi)不(bu)行(xing)的(de),所(suo)以(yi),鐵(tie)芯(xin)以(yi)及(ji)其(qi)夾(jia)件(jian)等(deng)都(dou)必(bi)須(xu)正(zheng)確(que)和(he)可(ke)靠(kao)地(di)接(jie)地(di)(隻有穿心螺栓的除外)。而(er)鐵(tie)芯(xin)隻(zhi)允(yun)許(xu)一(yi)點(dian)接(jie)地(di),如(ru)果(guo)有(you)兩(liang)點(dian)或(huo)者(zhe)多(duo)點(dian)接(jie)地(di),鐵(tie)芯(xin)就(jiu)會(hui)與(yu)接(jie)地(di)點(dian)和(he)大(da)地(di)構(gou)成(cheng)了(le)閉(bi)合(he)的(de)回(hui)路(lu)。變(bian)壓(ya)器(qi)運(yun)行(xing)的(de)時(shi)候(hou),有(you)磁(ci)通(tong)就(jiu)會(hui)穿(chuan)過(guo)此(ci)閉(bi)合(he)回(hui)路(lu),就(jiu)會(hui)產(chan)生(sheng)所(suo)謂(wei)的(de)環(huan)流(liu),引(yin)起(qi)鐵(tie)芯(xin)的(de)局(ju)部(bu)過(guo)熱(re),甚(shen)至(zhi)燒(shao)毀(hui)金(jin)屬(shu)部(bu)件(jian)以(yi)及(ji)絕(jue)緣(yuan)層(ceng)。
綜上所述:變壓器的鐵芯隻能一點接地,不能兩點或者多點接地。
(來源:網絡,版權歸原作者)