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        高壓真空斷路器特點(diǎn)

        2014/1/3 8:17:43      點(diǎn)擊:
        高壓真空斷路器 的特點(diǎn)①觸頭開(kāi)距小,10KV真空斷路器的觸頭開(kāi)距只有10mm左右,操作機(jī)構(gòu)的操作功就小,機(jī)械部分行程小,其機(jī)械壽命就長(zhǎng)。
        ②燃弧時(shí)間短,且與開(kāi)關(guān)電流大小無(wú)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(duì)開(kāi)斷近區(qū)故障性能較好。
        ④由于疏通在開(kāi)斷電流時(shí)磨損量較小,所以觸頭的電氣壽命長(zhǎng),滿容量開(kāi)斷達(dá)30-50次,額定電流開(kāi)斷達(dá)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(kāi)斷容性負(fù)荷電流。
        由于其優(yōu)點(diǎn)很多,所以廣泛應(yīng)用于變電站中,目前型號(hào)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(biāo)準(zhǔn)真空斷路器在我國(guó)近十年來(lái)得到了蓬勃的發(fā)展。產(chǎn)品從過(guò)去的ZN1~ZN5幾個(gè)品種發(fā)展到數(shù)十多個(gè)型號(hào)、品種,額定電流達(dá)到5000A,開(kāi)斷電流達(dá)到50kA的較好水平,并已發(fā)展到電壓達(dá)35kV等級(jí)。
        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(biāo)準(zhǔn),直到1985年后才制定相關(guān)的產(chǎn)品標(biāo)準(zhǔn)。
        國(guó)內(nèi)主要依據(jù)標(biāo)準(zhǔn):
        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(shuō)明:IEC標(biāo)準(zhǔn)中并無(wú)與我國(guó)JB3855相對(duì)應(yīng)的專用標(biāo)準(zhǔn),只是套用《IEC56交流高壓斷路器》。因此,我國(guó)真空斷路器的標(biāo)準(zhǔn)至少在下列幾個(gè)方面高于或嚴(yán)于IEC標(biāo)準(zhǔn):
        (1) 絕緣水平: 試驗(yàn)電壓 IEC 中國(guó)
        1min工頻耐壓(kV) 28 42(極間、極對(duì)地)48(斷口間)
        1.2/50沖擊耐壓(kV) 75 75(極間、極對(duì)地)84(斷口間)
        (2)電壽命試驗(yàn)結(jié)束后真空滅弧室斷口的耐壓水平:IEC56中無(wú)規(guī)定。我國(guó)JB3855一96規(guī)定為:完成電壽命次數(shù)試驗(yàn)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(shí)間:IEC無(wú)規(guī)定,而我國(guó)規(guī)定要求不大于2ms。
        (4)溫升試驗(yàn)的試驗(yàn)電流:IEC標(biāo)準(zhǔn)中,試驗(yàn)電流就等于產(chǎn)品的額定電流。我國(guó)DL403-91中規(guī)定試驗(yàn)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(yùn)行參數(shù)兩個(gè)方面。前者供用戶設(shè)計(jì)選型時(shí)使用;后者則是斷路器本身的機(jī)械特性或運(yùn)動(dòng)特性,為運(yùn)行、調(diào)整的技術(shù)指標(biāo)。
        下表是選用參數(shù)的列項(xiàng)說(shuō)明,并以三種真空斷路器數(shù)據(jù)為例。
        表中所列各項(xiàng)參數(shù),均須按JB3855和DL403標(biāo)準(zhǔn)的要求,在產(chǎn)品的型式試驗(yàn)中逐項(xiàng)加以驗(yàn)證,最終數(shù)據(jù)以型式試驗(yàn)報(bào)告為準(zhǔn)。
        工作原理

        真空斷路器的工作原理是:當(dāng)動(dòng)、靜觸頭在操作機(jī)構(gòu)的作用下分閘時(shí),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(jì)為特殊形狀,在電流通過(guò)時(shí)產(chǎn)生一磁場(chǎng),電弧在此磁場(chǎng)作用下沿觸頭表面切線方向快速運(yùn)動(dòng),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(guò)零時(shí)就熄滅了,觸頭間的介質(zhì)強(qiáng)度又迅速恢復(fù)起來(lái)。
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