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      1. 高壓真空斷路器特點

        2014/1/3 8:17:43      點擊:
        高壓真空斷路器 的特點①觸頭開距小,10KV真空斷路器的觸頭開距只有10mm左右,操作機構(gòu)的操作功就小,機械部分行程小,其機械壽命就長。
        ②燃弧時間短,且與開關(guān)電流大小無關(guān),一般只有半周波。
        ③熄弧后觸頭間隙介質(zhì)恢復(fù)速度快,對開斷近區(qū)故障性能較好。
        ④由于疏通在開斷電流時磨損量較小,所以觸頭的電氣壽命長,滿容量開斷達30-50次,額定電流開斷達5000次以上,噪音小適于頻繁操作。
        ⑤體積小、重量輕。
        ⑥適用于開斷容性負荷電流。
        由于其優(yōu)點很多,所以廣泛應(yīng)用于變電站中,目前型號主要有:ZN12-10型、ZN28A-10型、ZN65A-12型、ZN12A-12型、VS1型、ZN30型等。
        具體介紹

        真空斷路器技術(shù)標準真空斷路器在我國近十年來得到了蓬勃的發(fā)展。產(chǎn)品從過去的ZN1~ZN5幾個品種發(fā)展到數(shù)十多個型號、品種,額定電流達到5000A,開斷電流達到50kA的較好水平,并已發(fā)展到電壓達35kV等級。
        80年代以前,真空斷路器處于發(fā)展的起步階段,技術(shù)上在不斷摸索,還不能制定技術(shù)標準,直到1985年后才制定相關(guān)的產(chǎn)品標準。
        國內(nèi)主要依據(jù)標準:
        JP3855-96《3.6~40.5kV交流高壓真空斷路器通用技術(shù)條件》
        DL403-91《10~35kV戶內(nèi)高壓斷路器訂貨技術(shù)條件》
        這里需要說明:IEC標準中并無與我國JB3855相對應(yīng)的專用標準,只是套用《IEC56交流高壓斷路器》。因此,我國真空斷路器的標準至少在下列幾個方面高于或嚴于IEC標準:
        (1) 絕緣水平: 試驗電壓 IEC 中國
        1min工頻耐壓(kV) 28 42(極間、極對地)48(斷口間)
        1.2/50沖擊耐壓(kV) 75 75(極間、極對地)84(斷口間)
        (2)電壽命試驗結(jié)束后真空滅弧室斷口的耐壓水平:IEC56中無規(guī)定。我國JB3855一96規(guī)定為:完成電壽命次數(shù)試驗后的真空斷路器,其斷口間絕緣能力應(yīng)不低于初始絕緣水平的80%,即工頻1min33.6kV和沖擊60kV。
        (3)觸頭合閘彈跳時間:IEC無規(guī)定,而我國規(guī)定要求不大于2ms。
        (4)溫升試驗的試驗電流:IEC標準中,試驗電流就等于產(chǎn)品的額定電流。我國DL403-91中規(guī)定試驗電流為產(chǎn)品額定電流的110%。
        2.真空斷路器的主要技術(shù)參數(shù) 真空斷路器的參數(shù),大致可劃分為選用參數(shù)和運行參數(shù)兩個方面。前者供用戶設(shè)計選型時使用;后者則是斷路器本身的機械特性或運動特性,為運行、調(diào)整的技術(shù)指標。
        下表是選用參數(shù)的列項說明,并以三種真空斷路器數(shù)據(jù)為例。
        表中所列各項參數(shù),均須按JB3855和DL403標準的要求,在產(chǎn)品的型式試驗中逐項加以驗證,最終數(shù)據(jù)以型式試驗報告為準。
        工作原理

        真空斷路器的工作原理是:當動、靜觸頭在操作機構(gòu)的作用下分閘時,觸頭間產(chǎn)生電弧,觸頭表面在高溫下?lián)]發(fā)出蒸汽,由于觸頭設(shè)計為特殊形狀,在電流通過時產(chǎn)生一磁場,電弧在此磁場作用下沿觸頭表面切線方向快速運動,在金屬圓筒(屏蔽罩)上凝結(jié)了部分金屬蒸汽,電弧在自然過零時就熄滅了,觸頭間的介質(zhì)強度又迅速恢復(fù)起來。
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