配電變(bian)壓(ya)器保護措施(shi)研(yan)究

變壓(ya)(ya)器運行(xing)是(shi)否正常(chang)(chang)直(zhi)接(jie)影響用戶生(sheng)產和生(sheng)活用電(dian)(dian)，并關系(xi)到用電(dian)(dian)設備的(de)(de)安(an)全。為(wei)了(le)保(bao)(bao)證(zheng)用戶用上優質、安(an)全電(dian)(dian)，必須保(bao)(bao)證(zheng)配電(dian)(dian)變壓(ya)(ya)器運行(xing)正常(chang)(chang)，本文詳細論(lun)述了(le)在日常(chang)(chang)使用中配電(dian)(dian)變壓(ya)(ya)器的(de)(de)保(bao)(bao)護措施(shi)及其注(zhu)意(yi)事項。

配(pei)電(dian)(dian)(dian)(dian)(dian)變(bian)壓器是(shi)配(pei)電(dian)(dian)(dian)(dian)(dian)系統(tong)中根據電(dian)(dian)(dian)(dian)(dian)磁(ci)感應(ying)定律變(bian)換交流(liu)電(dian)(dian)(dian)(dian)(dian)壓和電(dian)(dian)(dian)(dian)(dian)流(liu)而傳輸交流(liu)電(dian)(dian)(dian)(dian)(dian)能的(de)一種靜(jing)止電(dian)(dian)(dian)(dian)(dian)器。通常(chang)(chang)(chang)安裝在電(dian)(dian)(dian)(dian)(dian)線桿、臺架或配(pei)電(dian)(dian)(dian)(dian)(dian)所(suo)中，一般將6-10千伏電(dian)(dian)(dian)(dian)(dian)壓降至400伏左右輸入用(yong)戶(hu)。所(suo)以(yi)我們有必要(yao)從(cong)保(bao)護配(pei)置技術角度和日常(chang)(chang)(chang)運(yun)行管理兩大方面(mian)來談談配(pei)電(dian)(dian)(dian)(dian)(dian)變(bian)壓器的(de)保(bao)護措施及其(qi)注意事項，以(yi)保(bao)證配(pei)電(dian)(dian)(dian)(dian)(dian)變(bian)壓器正常(chang)(chang)(chang)運(yun)行，保(bao)證用(yong)戶(hu)安全(quan)用(yong)電(dian)(dian)(dian)(dian)(dian)。

1保護(hu)配置技術方(fang)面

1.1裝(zhuang)設(she)避雷器保(bao)護(hu)，防止雷擊過電壓

配電變壓(ya)器(qi)是配電網中十分(fen)重要的(de)設(she)備，一旦(dan)發生雷(lei)擊損壞(huai)事(shi)故，就(jiu)會造成停電，直(zhi)接(jie)影響著工農(nong)業生產和人民生活(huo)。因此，在(zai)條件許可(ke)時，好(hao)采用避雷(lei)器(qi)來(lai)保護(hu)，在(zai)中性點不(bu)接(jie)地的(de)系(xi)統中，也可(ke)采用兩相(xiang)閥型避雷(lei)器(qi)—相(xiang)保護(hu)間(jian)隙的(de)保護(hu)方式。但同一配電網絡中，所有間(jian)隙必須(xu)裝在(zai)同一相(xiang)導線上，這(zhe)樣既(ji)可(ke)以節省一只閥型避雷(lei)器(qi)，而同時又不(bu)至于(yu)增(zeng)加線路跳閘的(de)次(ci)數。

保(bao)護(hu)變(bian)(bian)壓(ya)器(qi)(qi)(qi)的(de)閥型(xing)避(bi)(bi)雷器(qi)(qi)(qi)、管型(xing)避(bi)(bi)雷器(qi)(qi)(qi)或(huo)保(bao)護(hu)間(jian)隙，要求盡量靠近(jin)(jin)(jin)變(bian)(bian)壓(ya)器(qi)(qi)(qi)安裝(zhuang)，距離越近(jin)(jin)(jin)保(bao)護(hu)效(xiao)果越好，一般都要求裝(zhuang)在(zai)(zai)(zai)變(bian)(bian)壓(ya)器(qi)(qi)(qi)高(gao)(gao)壓(ya)側熔斷(duan)器(qi)(qi)(qi)內(nei)側。其接(jie)(jie)地(di)線(xian)，應(ying)(ying)和配電(dian)變(bian)(bian)壓(ya)器(qi)(qi)(qi)的(de)金(jin)屬外殼和低壓(ya)側中性點連在(zai)(zai)(zai)一起共同接(jie)(jie)地(di)。當(dang)(dang)(dang)變(bian)(bian)壓(ya)器(qi)(qi)(qi)容量為(wei)100kY˙A及以(yi)上(shang)時，接(jie)(jie)地(di)電(dian)阻應(ying)(ying)盡可(ke)(ke)能(neng)降(jiang)(jiang)低到(dao)4Ω以(yi)下(xia)；當(dang)(dang)(dang)變(bian)(bian)壓(ya)器(qi)(qi)(qi)容量小于(yu)100kV˙A時，接(jie)(jie)地(di)電(dian)阻10Ω及以(yi)下(xia)即(ji)可(ke)(ke)。當(dang)(dang)(dang)這—二點連在(zai)(zai)(zai)一起，高(gao)(gao)壓(ya)側落(luo)雷，避(bi)(bi)雷器(qi)(qi)(qi)或(huo)間(jian)隙放電(dian)時，變(bian)(bian)壓(ya)器(qi)(qi)(qi)絕緣所(suo)承(cheng)受的(de)即(ji)是(shi)閥型(xing)避(bi)(bi)雷器(qi)(qi)(qi)的(de)殘壓(ya)，而接(jie)(jie)地(di)裝(zhuang)置(zhi)上(shang)的(de)電(dian)壓(ya)降(jiang)(jiang)并沒(mei)有作用在(zai)(zai)(zai)變(bian)(bian)壓(ya)器(qi)(qi)(qi)的(de)絕緣上(shang)，這樣對變(bian)(bian)壓(ya)器(qi)(qi)(qi)保(bao)護(hu)是(shi)很有利的(de)，能(neng)降(jiang)(jiang)低高(gao)(gao)、低壓(ya)繞(rao)組(zu)(zu)間(jian)和高(gao)(gao)壓(ya)繞(rao)組(zu)(zu)對變(bian)(bian)壓(ya)器(qi)(qi)(qi)鐵心與外殼之間(jian)發生絕緣擊(ji)穿(chuan)的(de)危險(xian)。但是(shi)為(wei)了(le)防止變(bian)(bian)壓(ya)器(qi)(qi)(qi)低壓(ya)側中性點電(dian)位瞬(shun)時升高(gao)(gao)對用戶安全的(de)影響(xiang)，可(ke)(ke)以(yi)在(zai)(zai)(zai)靠近(jin)(jin)(jin)用戶的(de)地(di)方加裝(zhuang)輔助接(jie)(jie)地(di)線(xian)。

配電(dian)變(bian)壓(ya)(ya)(ya)器(qi)(qi)(qi)可能出(chu)(chu)現(xian)(xian)的(de)過(guo)電(dian)壓(ya)(ya)(ya)分兩種情況(kuang)：（1）正變(bian)換：當(dang)雷(lei)電(dian)波到達Y，y接(jie)線的(de)變(bian)壓(ya)(ya)(ya)器(qi)(qi)(qi)的(de)低壓(ya)(ya)(ya)繞(rao)組(zu)(zu)時(shi)，中性(xing)點(dian)(dian)所裝的(de)擊(ji)(ji)穿保險被(bei)擊(ji)(ji)穿，或(huo)當(dang)雷(lei)電(dian)波到達Y，Yn接(jie)線的(de)變(bian)壓(ya)(ya)(ya)器(qi)(qi)(qi)低壓(ya)(ya)(ya)繞(rao)組(zu)(zu)時(shi)，都會(hui)在(zai)(zai)外加電(dian)壓(ya)(ya)(ya)作用下，通(tong)過(guo)變(bian)壓(ya)(ya)(ya)器(qi)(qi)(qi)的(de)低壓(ya)(ya)(ya)繞(rao)組(zu)(zu)的(de)沖擊(ji)(ji)電(dian)流(liu)按(an)變(bian)比感應(ying)出(chu)(chu)電(dian)動勢(shi)，而使高(gao)壓(ya)(ya)(ya)繞(rao)組(zu)(zu)的(de)中性(xing)點(dian)(dian)電(dian)壓(ya)(ya)(ya)升(sheng)高(gao)。（2）反變(bian)換：當(dang)10kY側(ce)(ce)遭受雷(lei)擊(ji)(ji)時(shi)，經過(guo)避(bi)雷(lei)器(qi)(qi)(qi)會(hui)有較大的(de)雷(lei)電(dian)流(liu)通(tong)過(guo)，在(zai)(zai)接(jie)地裝置(zhi)上產生(sheng)電(dian)壓(ya)(ya)(ya)降，這個電(dian)壓(ya)(ya)(ya)降同(tong)時(shi)將作用在(zai)(zai)低壓(ya)(ya)(ya)繞(rao)組(zu)(zu)的(de)中性(xing)點(dian)(dian)并加到低壓(ya)(ya)(ya)繞(rao)組(zu)(zu)上，通(tong)過(guo)電(dian)磁感應(ying)也(ye)(ye)會(hui)在(zai)(zai)高(gao)壓(ya)(ya)(ya)側(ce)(ce)出(chu)(chu)現(xian)(xian)高(gao)電(dian)壓(ya)(ya)(ya)，對(dui)于星形接(jie)線的(de)變(bian)壓(ya)(ya)(ya)器(qi)(qi)(qi)，高(gao)壓(ya)(ya)(ya)側(ce)(ce)中性(xing)點(dian)(dian)上也(ye)(ye)會(hui)出(chu)(chu)現(xian)(xian)對(dui)絕緣有危險的(de)高(gao)電(dian)壓(ya)(ya)(ya)。另外也(ye)(ye)可根據(ju)具體情況(kuang)在(zai)(zai)變(bian)壓(ya)(ya)(ya)器(qi)(qi)(qi)低壓(ya)(ya)(ya)側(ce)(ce)加裝避(bi)雷(lei)器(qi)(qi)(qi)或(huo)擊(ji)(ji)穿保險器(qi)(qi)(qi)，能進一步提高(gao)變(bian)壓(ya)(ya)(ya)器(qi)(qi)(qi)安全(quan)可靠(kao)性(xing)。

運行經驗證明，處在(zai)多雷(lei)(lei)地區的(de)(de)(de)(de)配電(dian)(dian)變(bian)(bian)壓(ya)器(qi)(qi)(qi)(qi)，雖然(ran)裝(zhuang)了閥型避雷(lei)(lei)器(qi)(qi)(qi)(qi)保(bao)護(hu)，但因雷(lei)(lei)擊(ji)引起損壞者仍然(ran)不少(shao)(shao)，，根(gen)(gen)據(ju)事故(gu)教(jiao)訓，為(wei)了減少(shao)(shao)配電(dian)(dian)變(bian)(bian)壓(ya)器(qi)(qi)(qi)(qi)事故(gu)，還(huan)應(ying)根(gen)(gen)據(ju)具(ju)體情況采取下列(lie)技術措施：（1）消除配電(dian)(dian)變(bian)(bian)壓(ya)器(qi)(qi)(qi)(qi)本(ben)身(shen)的(de)(de)(de)(de)絕(jue)緣(yuan)薄(bo)弱(ruo)點(dian)。在(zai)運行葉，還(huan)應(ying)加強對變(bian)(bian)壓(ya)器(qi)(qi)(qi)(qi)絕(jue)緣(yuan)油的(de)(de)(de)(de)試驗和(he)分析(xi)，因絕(jue)緣(yuan)油劣化會(hui)直(zhi)(zhi)接導致繞組(zu)絕(jue)緣(yuan)的(de)(de)(de)(de)降低(di)，所以(yi)(yi)發(fa)現問(wen)題后必須及時(shi)進(jin)行處理或更換。對配電(dian)(dian)變(bian)(bian)壓(ya)器(qi)(qi)(qi)(qi)進(jin)行廣泛(fan)的(de)(de)(de)(de)沖擊(ji)試驗和(he)匝(za)間(jian)試驗，能有效地發(fa)現變(bian)(bian)壓(ya)器(qi)(qi)(qi)(qi)上存在(zai)的(de)(de)(de)(de)絕(jue)緣(yuan)弱(ruo)點(dian)，及時(shi)安排檢修，能減少(shao)(shao)雷(lei)(lei)擊(ji)損壞事故(gu)，（2）裝(zhuang)在(zai)木(mu)桿線路上的(de)(de)(de)(de)配電(dian)(dian)變(bian)(bian)壓(ya)器(qi)(qi)(qi)(qi)，可(ke)在(zai)變(bian)(bian)壓(ya)器(qi)(qi)(qi)(qi)進(jin)線段內(nei)裝(zhuang)設保(bao)護(hu)間(jian)隙(xi)，或將導線為(wei)三角排列(lie)的(de)(de)(de)(de)頂相絕(jue)緣(yuan)子的(de)(de)(de)(de)鐵腳(jiao)接地，以(yi)(yi)降低(di)雷(lei)(lei)電(dian)(dian)侵入(ru)波的(de)(de)(de)(de)陡(dou)度和(he)減少(shao)(shao)流(liu)(liu)過閥型避雷(lei)(lei)器(qi)(qi)(qi)(qi)的(de)(de)(de)(de)電(dian)(dian)流(liu)(liu)。（3）也可(ke)考慮在(zai)配電(dian)(dian)變(bian)(bian)壓(ya)器(qi)(qi)(qi)(qi)與閥型避雷(lei)(lei)器(qi)(qi)(qi)(qi)之(zhi)間(jian)，加裝(zhuang)一(yi)組(zu)電(dian)(dian)感線圈（30匝(za)左(zuo)右，長(chang)24cm，直(zhi)(zhi)徑20cm，電(dian)(dian)感值約為(wei)100μH），以(yi)(yi)限制雷(lei)(lei)電(dian)(dian)侵入(ru)波的(de)(de)(de)(de)陡(dou)度，從而降低(di)變(bian)(bian)壓(ya)器(qi)(qi)(qi)(qi)繞組(zu)層間(jian)絕(jue)緣(yuan)上的(de)(de)(de)(de)過電(dian)(dian)壓(ya)。