配電變壓(ya)器保護措施研究

變(bian)壓(ya)器運(yun)行是否(fou)正常(chang)直接影響用(yong)戶生產(chan)和生活用(yong)電(dian)，并關(guan)系到(dao)用(yong)電(dian)設備(bei)的安全。為了保證用(yong)戶用(yong)上優(you)質、安全電(dian)，必須(xu)保證配電(dian)變(bian)壓(ya)器運(yun)行正常(chang)，本文詳細論(lun)述(shu)了在日常(chang)使用(yong)中配電(dian)變(bian)壓(ya)器的保護措施(shi)及其注意(yi)事項。

配(pei)(pei)電(dian)變壓器(qi)是(shi)配(pei)(pei)電(dian)系統中根據電(dian)磁感(gan)應定律(lv)變換交(jiao)流電(dian)壓和電(dian)流而傳輸(shu)交(jiao)流電(dian)能的一(yi)種靜止電(dian)器(qi)。通常安裝(zhuang)在電(dian)線桿、臺架或(huo)配(pei)(pei)電(dian)所(suo)中，一(yi)般將6-10千伏電(dian)壓降至400伏左(zuo)右(you)輸(shu)入用戶。所(suo)以我們有必要(yao)從保(bao)(bao)護配(pei)(pei)置技術角度(du)和日常運(yun)行(xing)管理兩大方面來談(tan)談(tan)配(pei)(pei)電(dian)變壓器(qi)的保(bao)(bao)護措施及其注意事項，以保(bao)(bao)證配(pei)(pei)電(dian)變壓器(qi)正常運(yun)行(xing)，保(bao)(bao)證用戶安全用電(dian)。

1保護配(pei)置技術方面(mian)

1.1裝設(she)避雷器保護，防止雷擊過電壓(ya)

配(pei)(pei)電(dian)變壓器(qi)(qi)是配(pei)(pei)電(dian)網中(zhong)十(shi)分重要的(de)設備，一(yi)(yi)旦發生(sheng)雷擊(ji)損壞事故，就(jiu)會(hui)造成停電(dian)，直接影(ying)響著工農(nong)業(ye)生(sheng)產和人(ren)民生(sheng)活(huo)。因此，在(zai)條件許可(ke)時，好采(cai)用(yong)避(bi)雷器(qi)(qi)來保護，在(zai)中(zhong)性(xing)點不接地的(de)系統中(zhong)，也可(ke)采(cai)用(yong)兩相閥型避(bi)雷器(qi)(qi)—相保護間(jian)隙(xi)的(de)保護方式。但同(tong)一(yi)(yi)配(pei)(pei)電(dian)網絡中(zhong)，所(suo)有(you)間(jian)隙(xi)必須裝在(zai)同(tong)一(yi)(yi)相導線上，這(zhe)樣既可(ke)以節省一(yi)(yi)只閥型避(bi)雷器(qi)(qi)，而同(tong)時又不至(zhi)于增加線路跳閘(zha)的(de)次數。

保(bao)護(hu)(hu)變(bian)(bian)壓(ya)器(qi)(qi)(qi)(qi)的(de)(de)(de)閥(fa)型避雷(lei)(lei)(lei)器(qi)(qi)(qi)(qi)、管型避雷(lei)(lei)(lei)器(qi)(qi)(qi)(qi)或保(bao)護(hu)(hu)間(jian)(jian)隙，要(yao)求(qiu)盡(jin)量(liang)靠近(jin)變(bian)(bian)壓(ya)器(qi)(qi)(qi)(qi)安(an)裝(zhuang)(zhuang)，距離越近(jin)保(bao)護(hu)(hu)效果越好，一般都(dou)要(yao)求(qiu)裝(zhuang)(zhuang)在(zai)(zai)變(bian)(bian)壓(ya)器(qi)(qi)(qi)(qi)高(gao)壓(ya)側熔斷(duan)器(qi)(qi)(qi)(qi)內側。其(qi)接(jie)(jie)(jie)地(di)(di)線，應和(he)配電變(bian)(bian)壓(ya)器(qi)(qi)(qi)(qi)的(de)(de)(de)金(jin)屬外殼和(he)低(di)壓(ya)側中性點連在(zai)(zai)一起共同接(jie)(jie)(jie)地(di)(di)。當變(bian)(bian)壓(ya)器(qi)(qi)(qi)(qi)容(rong)量(liang)為100kY˙A及以(yi)上時，接(jie)(jie)(jie)地(di)(di)電阻應盡(jin)可能降(jiang)低(di)到4Ω以(yi)下(xia)；當變(bian)(bian)壓(ya)器(qi)(qi)(qi)(qi)容(rong)量(liang)小于100kV˙A時，接(jie)(jie)(jie)地(di)(di)電阻10Ω及以(yi)下(xia)即(ji)可。當這—二點連在(zai)(zai)一起，高(gao)壓(ya)側落雷(lei)(lei)(lei)，避雷(lei)(lei)(lei)器(qi)(qi)(qi)(qi)或間(jian)(jian)隙放電時，變(bian)(bian)壓(ya)器(qi)(qi)(qi)(qi)絕(jue)緣所承受的(de)(de)(de)即(ji)是閥(fa)型避雷(lei)(lei)(lei)器(qi)(qi)(qi)(qi)的(de)(de)(de)殘壓(ya)，而接(jie)(jie)(jie)地(di)(di)裝(zhuang)(zhuang)置上的(de)(de)(de)電壓(ya)降(jiang)并沒有作用(yong)在(zai)(zai)變(bian)(bian)壓(ya)器(qi)(qi)(qi)(qi)的(de)(de)(de)絕(jue)緣上，這樣對變(bian)(bian)壓(ya)器(qi)(qi)(qi)(qi)保(bao)護(hu)(hu)是很(hen)有利的(de)(de)(de)，能降(jiang)低(di)高(gao)、低(di)壓(ya)繞組間(jian)(jian)和(he)高(gao)壓(ya)繞組對變(bian)(bian)壓(ya)器(qi)(qi)(qi)(qi)鐵心與外殼之(zhi)間(jian)(jian)發生絕(jue)緣擊穿的(de)(de)(de)危險。但是為了防止變(bian)(bian)壓(ya)器(qi)(qi)(qi)(qi)低(di)壓(ya)側中性點電位瞬時升高(gao)對用(yong)戶(hu)安(an)全(quan)的(de)(de)(de)影響，可以(yi)在(zai)(zai)靠近(jin)用(yong)戶(hu)的(de)(de)(de)地(di)(di)方加裝(zhuang)(zhuang)輔助接(jie)(jie)(jie)地(di)(di)線。

配電(dian)變(bian)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)(qi)可(ke)能(neng)出現的(de)(de)(de)過(guo)(guo)電(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)分(fen)兩種情況：（1）正(zheng)變(bian)換(huan)：當(dang)雷(lei)電(dian)波(bo)到達Y，y接(jie)線(xian)的(de)(de)(de)變(bian)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)(qi)的(de)(de)(de)低(di)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)繞(rao)組(zu)時，中性(xing)點所(suo)裝(zhuang)(zhuang)的(de)(de)(de)擊(ji)(ji)(ji)穿保(bao)(bao)險(xian)被(bei)擊(ji)(ji)(ji)穿，或當(dang)雷(lei)電(dian)波(bo)到達Y，Yn接(jie)線(xian)的(de)(de)(de)變(bian)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)(qi)低(di)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)繞(rao)組(zu)時，都(dou)會(hui)在外(wai)加(jia)電(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)作用下，通(tong)過(guo)(guo)變(bian)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)(qi)的(de)(de)(de)低(di)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)繞(rao)組(zu)的(de)(de)(de)沖擊(ji)(ji)(ji)電(dian)流按變(bian)比感(gan)應出電(dian)動勢，而使高壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)繞(rao)組(zu)的(de)(de)(de)中性(xing)點電(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)升高。（2）反變(bian)換(huan)：當(dang)10kY側(ce)(ce)遭(zao)受雷(lei)擊(ji)(ji)(ji)時，經過(guo)(guo)避雷(lei)器(qi)(qi)(qi)(qi)會(hui)有(you)較(jiao)大的(de)(de)(de)雷(lei)電(dian)流通(tong)過(guo)(guo)，在接(jie)地裝(zhuang)(zhuang)置上(shang)產生電(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)降(jiang)，這(zhe)個電(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)降(jiang)同時將作用在低(di)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)繞(rao)組(zu)的(de)(de)(de)中性(xing)點并加(jia)到低(di)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)繞(rao)組(zu)上(shang)，通(tong)過(guo)(guo)電(dian)磁感(gan)應也會(hui)在高壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)側(ce)(ce)出現高電(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)，對于星形(xing)接(jie)線(xian)的(de)(de)(de)變(bian)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)(qi)，高壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)側(ce)(ce)中性(xing)點上(shang)也會(hui)出現對絕緣(yuan)有(you)危(wei)險(xian)的(de)(de)(de)高電(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)。另外(wai)也可(ke)根(gen)據(ju)具體情況在變(bian)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)(qi)低(di)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)側(ce)(ce)加(jia)裝(zhuang)(zhuang)避雷(lei)器(qi)(qi)(qi)(qi)或擊(ji)(ji)(ji)穿保(bao)(bao)險(xian)器(qi)(qi)(qi)(qi)，能(neng)進一步提高變(bian)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)器(qi)(qi)(qi)(qi)安全可(ke)靠性(xing)。

運(yun)行(xing)經驗證明，處在多雷(lei)(lei)(lei)地(di)區(qu)的(de)(de)(de)(de)(de)配電(dian)變(bian)(bian)(bian)壓(ya)器(qi)(qi)，雖然裝了閥(fa)型避雷(lei)(lei)(lei)器(qi)(qi)保護(hu)，但(dan)因雷(lei)(lei)(lei)擊引(yin)起損(sun)壞(huai)者仍然不(bu)少，，根據事(shi)故教訓，為(wei)了減(jian)(jian)少配電(dian)變(bian)(bian)(bian)壓(ya)器(qi)(qi)事(shi)故，還(huan)應根據具體(ti)情(qing)況采取下(xia)列技(ji)術措施：（1）消除配電(dian)變(bian)(bian)(bian)壓(ya)器(qi)(qi)本身的(de)(de)(de)(de)(de)絕(jue)(jue)緣(yuan)(yuan)薄(bo)弱(ruo)點。在運(yun)行(xing)葉，還(huan)應加強對變(bian)(bian)(bian)壓(ya)器(qi)(qi)絕(jue)(jue)緣(yuan)(yuan)油的(de)(de)(de)(de)(de)試驗和(he)分析，因絕(jue)(jue)緣(yuan)(yuan)油劣化(hua)會直接(jie)導(dao)致繞(rao)組(zu)絕(jue)(jue)緣(yuan)(yuan)的(de)(de)(de)(de)(de)降(jiang)(jiang)低(di)(di)，所以(yi)(yi)發現問題后必須及時(shi)進(jin)(jin)行(xing)處理(li)或(huo)更換。對配電(dian)變(bian)(bian)(bian)壓(ya)器(qi)(qi)進(jin)(jin)行(xing)廣泛的(de)(de)(de)(de)(de)沖擊試驗和(he)匝間(jian)(jian)試驗，能(neng)有效(xiao)地(di)發現變(bian)(bian)(bian)壓(ya)器(qi)(qi)上(shang)存在的(de)(de)(de)(de)(de)絕(jue)(jue)緣(yuan)(yuan)弱(ruo)點，及時(shi)安排檢(jian)修，能(neng)減(jian)(jian)少雷(lei)(lei)(lei)擊損(sun)壞(huai)事(shi)故，（2）裝在木桿線路(lu)上(shang)的(de)(de)(de)(de)(de)配電(dian)變(bian)(bian)(bian)壓(ya)器(qi)(qi)，可在變(bian)(bian)(bian)壓(ya)器(qi)(qi)進(jin)(jin)線段內裝設(she)保護(hu)間(jian)(jian)隙，或(huo)將導(dao)線為(wei)三角(jiao)排列的(de)(de)(de)(de)(de)頂相絕(jue)(jue)緣(yuan)(yuan)子(zi)的(de)(de)(de)(de)(de)鐵腳接(jie)地(di)，以(yi)(yi)降(jiang)(jiang)低(di)(di)雷(lei)(lei)(lei)電(dian)侵(qin)入(ru)(ru)波(bo)的(de)(de)(de)(de)(de)陡(dou)度和(he)減(jian)(jian)少流過閥(fa)型避雷(lei)(lei)(lei)器(qi)(qi)的(de)(de)(de)(de)(de)電(dian)流。（3）也可考慮(lv)在配電(dian)變(bian)(bian)(bian)壓(ya)器(qi)(qi)與(yu)閥(fa)型避雷(lei)(lei)(lei)器(qi)(qi)之間(jian)(jian)，加裝一組(zu)電(dian)感線圈（30匝左右，長24cm，直徑20cm，電(dian)感值約為(wei)100μH），以(yi)(yi)限制雷(lei)(lei)(lei)電(dian)侵(qin)入(ru)(ru)波(bo)的(de)(de)(de)(de)(de)陡(dou)度，從(cong)而降(jiang)(jiang)低(di)(di)變(bian)(bian)(bian)壓(ya)器(qi)(qi)繞(rao)組(zu)層間(jian)(jian)絕(jue)(jue)緣(yuan)(yuan)上(shang)的(de)(de)(de)(de)(de)過電(dian)壓(ya)。