防雷器的工作原理
1.管(guan)(guan)(guan)式避(bi)雷(lei)(lei)器，其基本工作原理是內(nei)(nei)間隙(又稱滅(mie)弧(hu)間隙)置于產(chan)氣(qi)(qi)材料制成的(de)(de)滅(mie)弧(hu)管(guan)(guan)(guan)內(nei)(nei)，外間隙將管(guan)(guan)(guan)子與電(dian)網(wang)隔開。雷(lei)(lei)電(dian)過(guo)電(dian)壓使內(nei)(nei)外間隙放電(dian)，內(nei)(nei)間隙電(dian)弧(hu)高(gao)(gao)溫使產(chan)氣(qi)(qi)材料產(chan)生氣(qi)(qi)體(ti)，管(guan)(guan)(guan)內(nei)(nei)氣(qi)(qi)壓迅速增加，高(gao)(gao)壓氣(qi)(qi)體(ti)從噴(pen)口噴(pen)出滅(mie)弧(hu)。管(guan)(guan)(guan)式避(bi)雷(lei)(lei)器具有(you)較(jiao)大的(de)(de)沖擊通流能力，可(ke)用在(zai)雷(lei)(lei)電(dian)流幅(fu)值很大的(de)(de)地方。但管(guan)(guan)(guan)式避(bi)雷(lei)(lei)器放電(dian)電(dian)壓較(jiao)高(gao)(gao)且分散(san)性大，動作時產(chan)生截波，保(bao)護(hu)性能較(jiao)差。主要用于變電(dian)所、發電(dian)廠的(de)(de)進線(xian)保(bao)護(hu)和線(xian)路絕緣弱點的(de)(de)保(bao)護(hu)。
2.碳(tan)(tan)化(hua)(hua)硅(gui)避雷器(qi)(qi)(qi)，其(qi)(qi)基本(ben)工作(zuo)(zuo)(zuo)原理是(shi)疊裝于密封瓷(ci)套(tao)(tao)內的火(huo)(huo)花間(jian)隙(xi)和碳(tan)(tan)化(hua)(hua)硅(gui)閥片(電(dian)(dian)壓(ya)(ya)等級高(gao)(gao)(gao)的避雷器(qi)(qi)(qi)產品具有(you)多節瓷(ci)套(tao)(tao))。火(huo)(huo)花間(jian)隙(xi)的主(zhu)要作(zuo)(zuo)(zuo)用(yong)(yong)(yong)是(shi)平時(shi)將閥片與(yu)帶電(dian)(dian)導體隔離(li)，在(zai)過(guo)電(dian)(dian)壓(ya)(ya)時(shi)放(fang)電(dian)(dian)和切斷(duan)電(dian)(dian)源供給的續流(liu)。碳(tan)(tan)化(hua)(hua)硅(gui)避雷器(qi)(qi)(qi)的火(huo)(huo)花間(jian)隙(xi)由許多間(jian)隙(xi)串聯組成，放(fang)電(dian)(dian)分散(san)性(xing)(xing)小，伏秒特性(xing)(xing)平坦，滅弧性(xing)(xing)能(neng)(neng)(neng)好。碳(tan)(tan)化(hua)(hua)硅(gui)閥片是(shi)以(yi)電(dian)(dian)工碳(tan)(tan)化(hua)(hua)硅(gui)為主(zhu)體，與(yu)結合劑混合后，經壓(ya)(ya)形、燒結而成的非線(xian)性(xing)(xing)電(dian)(dian)阻體，呈(cheng)圓餅狀(zhuang)。碳(tan)(tan)化(hua)(hua)硅(gui)閥片的主(zhu)要作(zuo)(zuo)(zuo)用(yong)(yong)(yong)是(shi)吸收過(guo)電(dian)(dian)壓(ya)(ya)能(neng)(neng)(neng)量，利(li)用(yong)(yong)(yong)其(qi)(qi)電(dian)(dian)阻的非線(xian)性(xing)(xing)(高(gao)(gao)(gao)電(dian)(dian)壓(ya)(ya)大電(dian)(dian)流(liu)下(xia)電(dian)(dian)阻值大幅度下(xia)降)限制(zhi)放(fang)電(dian)(dian)電(dian)(dian)流(liu)通過(guo)自身的壓(ya)(ya)降(稱殘(can)壓(ya)(ya))和限制(zhi)續流(liu)幅值，與(yu)火(huo)(huo)花間(jian)隙(xi)協(xie)同(tong)作(zuo)(zuo)(zuo)用(yong)(yong)(yong)熄滅續流(liu)電(dian)(dian)弧。碳(tan)(tan)化(hua)(hua)硅(gui)避雷器(qi)(qi)(qi)按結構(gou)不同(tong)，又分為普通閥式和磁(ci)吹閥式兩類。后者利(li)用(yong)(yong)(yong)磁(ci)場驅動電(dian)(dian)弧來提(ti)高(gao)(gao)(gao)滅弧性(xing)(xing)能(neng)(neng)(neng)，從而具有(you)更好的保(bao)護(hu)性(xing)(xing)能(neng)(neng)(neng)。碳(tan)(tan)化(hua)(hua)硅(gui)避雷器(qi)(qi)(qi)保(bao)護(hu)性(xing)(xing)能(neng)(neng)(neng)好，廣泛(fan)用(yong)(yong)(yong)于交、直(zhi)流(liu)系(xi)統，保(bao)護(hu)發電(dian)(dian)、變(bian)電(dian)(dian)設備的絕(jue)緣。
3.金(jin)屬(shu)氧(yang)化(hua)(hua)(hua)物避(bi)雷器(qi)，其基本工作(zuo)(zuo)原(yuan)理是密封在(zai)瓷套內的(de)(de)氧(yang)化(hua)(hua)(hua)鋅(xin)(xin)(xin)閥片。氧(yang)化(hua)(hua)(hua)鋅(xin)(xin)(xin)閥片是以ZnO為基體,添加少量(liang)的(de)(de) Bi2O3、MnO2、Sb2O3、Co3O3、Cr2O3等(deng)制成的(de)(de)非(fei)線性(xing)(xing)電(dian)阻體，具有比碳(tan)化(hua)(hua)(hua)硅(gui)好得多(duo)的(de)(de)非(fei)線性(xing)(xing)伏安特(te)性(xing)(xing)，在(zai)持續(xu)工作(zuo)(zuo)電(dian)壓(ya)下僅流(liu)過(guo)微安級(ji)的(de)(de)泄漏電(dian)流(liu)，動作(zuo)(zuo)后無續(xu)流(liu)。因(yin)此金(jin)屬(shu)氧(yang)化(hua)(hua)(hua)鋅(xin)(xin)(xin)避(bi)雷器(qi)不需要火花(hua)間隙，從而使結構簡化(hua)(hua)(hua)，并具有動作(zuo)(zuo)響應快、耐(nai)多(duo)重雷電(dian)過(guo)電(dian)壓(ya)或操作(zuo)(zuo)過(guo)電(dian)壓(ya)作(zuo)(zuo)用(yong)、能量(liang)吸收能力大、耐(nai)污穢性(xing)(xing)能好等(deng)優點(dian)。由于金(jin)屬(shu)氧(yang)化(hua)(hua)(hua)鋅(xin)(xin)(xin)避(bi)雷器(qi)保護性(xing)(xing)能優于碳(tan)化(hua)(hua)(hua)硅(gui)避(bi)雷器(qi)，已在(zai)逐步取(qu)代碳(tan)化(hua)(hua)(hua)硅(gui)避(bi)雷器(qi)，廣(guang)泛用(yong)于交、直流(liu)系(xi)統(tong)，保護發電(dian)、變電(dian)設備(bei)的(de)(de)絕(jue)緣，尤其適合于中(zhong)性(xing)(xing)點(dian)有效接(jie)(jie)地(見電(dian)力系(xi)統(tong)中(zhong)性(xing)(xing)點(dian)接(jie)(jie)地方式)的(de)(de)110千伏及以上電(dian)網。
