低壓電容柜在電(dian)氣供電(dian)系統中的(de)作用是不可或缺的(de)，能夠有效提高電(dian)網的(de)功率因數，改善電(dian)能質量。在工作中，大家(jia)會經(jing)常(chang)遇到低(di)壓電(dian)容柜相關(guan)問題(ti)不夠了解的(de)地方，今天就為(wei)大家(jia)整(zheng)理了相關(guan)常(chang)見的(de)問題(ti)及(ji)解決方案(an)。

一(yi)、為什么要在(zai)系統安裝電(dian)(dian)力電(dian)(dian)容補償裝置？工業生產廣泛使(shi)用的交(jiao)流異步電(dian)(dian)動(dong)機(ji)(ji)、電(dian)(dian)焊機(ji)(ji)、電(dian)(dian)磁(ci)爐等設備都(dou)是感(gan)性(xing)負載，這些感(gan)性(xing)的負載在(zai)進行能量轉(zhuan)換過程中，使(shi)加在(zai)其上的電(dian)(dian)壓(ya)超(chao)前(qian)電(dian)(dian)流一(yi)個角(jiao)度，這個角(jiao)度的余(yu)弦cosΦ叫(jiao)做功(gong)(gong)率(lv)因數。當功(gong)(gong)率(lv)因數即(ji)無功(gong)(gong)功(gong)(gong)率(lv)很大時(shi)，會有以(yi)下(xia)危(wei)害：

（1）增(zeng)大(da)線路(lu)電流，使線路(lu)損(sun)耗加(jia)大(da)，浪(lang)費電能；

（2）因線(xian)路電(dian)流增(zeng)大，一旦輸電(dian)線(xian)路較遠，線(xian)路上的電(dian)壓降就大，電(dian)壓過低(di)就可(ke)能影響設備正常使用(yong)；

（3）對變(bian)(bian)(bian)壓(ya)器(qi)(qi)或(huo)者(zhe)(zhe)(zhe)發(fa)(fa)電(dian)(dian)機(ji)而言(yan)，無功(gong)功(gong)率(lv)大(da)(da)，變(bian)(bian)(bian)壓(ya)器(qi)(qi)或(huo)者(zhe)(zhe)(zhe)發(fa)(fa)電(dian)(dian)機(ji)輸出的電(dian)(dian)流也大(da)(da)，往往是輸出電(dian)(dian)流已達額定值(zhi)，這時(shi)負荷(he)若再增(zeng)加就(jiu)需要(yao)加多(duo)一(yi)臺變(bian)(bian)(bian)壓(ya)器(qi)(qi)或(huo)者(zhe)(zhe)(zhe)發(fa)(fa)電(dian)(dian)機(ji)組(zu)，浪費資源(yuan)(yuan)；補償了(le)電(dian)(dian)容后，同樣負荷(he)下變(bian)(bian)(bian)壓(ya)器(qi)(qi)或(huo)者(zhe)(zhe)(zhe)發(fa)(fa)電(dian)(dian)機(ji)輸出電(dian)(dian)流大(da)(da)大(da)(da)降低，再增(zeng)加負荷(he)機(ji)組(zu)也能承受，無需再加一(yi)臺變(bian)(bian)(bian)壓(ya)器(qi)(qi)或(huo)者(zhe)(zhe)(zhe)發(fa)(fa)電(dian)(dian)機(ji)，可(ke)節省(sheng)資源(yuan)(yuan)。

（4）月平(ping)均(jun)功率因(yin)數工業用(yong)戶(hu)低(di)于0.92、普通(tong)用(yong)戶(hu)低(di)于0.9要被供電管理部門處于不同額度的(de)罰款。增加(jia)并聯(lian)電容補償(chang)柜是補償(chang)功率因(yin)數的(de)方法之一。

二、為什么電容器(qi)的保護控制電器(qi)和(he)導線要求按照(zhao)電容器(qi)額(e)定(ding)電流的1.5倍來(lai)選擇?

開關(guan)、保(bao)護(hu)(hu)裝置(zhi)及(ji)連接(jie)件開關(guan)、保(bao)護(hu)(hu)裝置(zhi)及(ji)連接(jie)件均應設(she)計成(cheng)能連續承(cheng)受在額(e)定(ding)頻率和方均根值等(deng)于額(e)定(ding)電(dian)(dian)(dian)壓的(de)(de)正(zheng)弦電(dian)(dian)(dian)壓下(xia)得到(dao)的(de)(de)電(dian)(dian)(dian)流(liu)的(de)(de)1.3倍的(de)(de)電(dian)(dian)(dian)流(liu)。因(yin)為(wei)(wei)電(dian)(dian)(dian)容器(qi)(qi)的(de)(de)電(dian)(dian)(dian)容可能為(wei)(wei)額(e)定(ding)值的(de)(de)1.10倍，故這一電(dian)(dian)(dian)流(liu)最大值為(wei)(wei)1.3*1.1倍額(e)定(ding)電(dian)(dian)(dian)流(liu)，即1.43In。不(bu)同的(de)(de)電(dian)(dian)(dian)容器(qi)(qi)保(bao)護(hu)(hu)電(dian)(dian)(dian)器(qi)(qi)，其選(xuan)擇不(bu)同，并非(fei)1.5倍這么簡單。比如熔斷器(qi)(qi)應選(xuan)1.7~1.9倍之間，主要為(wei)(wei)短路保(bao)護(hu)(hu)。過(guo)載保(bao)護(hu)(hu)用熱繼電(dian)(dian)(dian)器(qi)(qi)或電(dian)(dian)(dian)容器(qi)(qi)保(bao)護(hu)(hu)器(qi)(qi)，一般按電(dian)(dian)(dian)容器(qi)(qi)額(e)定(ding)電(dian)(dian)(dian)流(liu)的(de)(de)1.15倍整(zheng)定(ding)。因(yin)為(wei)(wei)熱繼電(dian)(dian)(dian)器(qi)(qi)在整(zheng)定(ding)值1.2倍2小時以內不(bu)會(hui)動作，如整(zheng)定(ding)1.5倍，那(nei)過(guo)載保(bao)護(hu)(hu)就成(cheng)了個(ge)擺設(she)。

三、補(bu)償柜中熔(rong)斷器(qi)為何(he)不能用微(wei)型斷路器(qi)來(lai)代替(ti)?

熔(rong)斷(duan)(duan)(duan)(duan)器(qi)主要為短路(lu)保護應(ying)選(xuan)用快(kuai)速熔(rong)斷(duan)(duan)(duan)(duan)器(qi)，微(wei)斷(duan)(duan)(duan)(duan)與熔(rong)斷(duan)(duan)(duan)(duan)器(qi)特性曲線不(bu)同，微(wei)斷(duan)(duan)(duan)(duan)的分(fen)斷(duan)(duan)(duan)(duan)能力(li)太低（<=6000A），遇到(dao)事故(gu)響應(ying)時間沒有熔(rong)斷(duan)(duan)(duan)(duan)器(qi)快(kuai)，當遇到(dao)高(gao)次諧波時，微(wei)斷(duan)(duan)(duan)(duan)分(fen)斷(duan)(duan)(duan)(duan)不(bu)了負荷電(dian)流會造成開關炸開損壞，因為故(gu)障電(dian)流過大，結果微(wei)斷(duan)(duan)(duan)(duan)觸點(dian)燒了，斷(duan)(duan)(duan)(duan)不(bu)了擴大故(gu)障范圍，嚴重時發生短路(lu)引起全廠停電(dian)事故(gu)。所以電(dian)容柜不(bu)能用微(wei)斷(duan)(duan)(duan)(duan)代替熔(rong)斷(duan)(duan)(duan)(duan)器(qi)。

四、補(bu)償柜(ju)中熱繼(ji)電(dian)器何種情況下(xia)可省略?

一般靜態補償(chang)(chang)方(fang)案：刀熔(rong)開(kai)關→熔(rong)斷(duan)器(qi)(qi)→接(jie)(jie)觸器(qi)(qi)→熱(re)(re)(re)(re)繼(ji)電(dian)(dian)(dian)(dian)器(qi)(qi)→（電(dian)(dian)(dian)(dian)抗器(qi)(qi)）→電(dian)(dian)(dian)(dian)容器(qi)(qi)。熱(re)(re)(re)(re)繼(ji)電(dian)(dian)(dian)(dian)器(qi)(qi)起(qi)到過載(zai)保(bao)(bao)護(hu)功能，現在的(de)電(dian)(dian)(dian)(dian)網中(zhong)諧波、過電(dian)(dian)(dian)(dian)壓隨時(shi)都(dou)可(ke)(ke)能造成電(dian)(dian)(dian)(dian)容器(qi)(qi)的(de)過載(zai)。熱(re)(re)(re)(re)繼(ji)電(dian)(dian)(dian)(dian)器(qi)(qi)過載(zai)動(dong)作從而起(qi)到保(bao)(bao)護(hu)電(dian)(dian)(dian)(dian)容器(qi)(qi)的(de)作用。如果選用的(de)熱(re)(re)(re)(re)繼(ji)電(dian)(dian)(dian)(dian)器(qi)(qi)帶斷(duan)相(xiang)保(bao)(bao)護(hu)功能，同樣在電(dian)(dian)(dian)(dian)容器(qi)(qi)缺相(xiang)時(shi)能通過斷(duan)開(kai)接(jie)(jie)觸器(qi)(qi)回路來切除電(dian)(dian)(dian)(dian)容，起(qi)到斷(duan)相(xiang)保(bao)(bao)護(hu)。熱(re)(re)(re)(re)繼(ji)電(dian)(dian)(dian)(dian)器(qi)(qi)的(de)過載(zai)保(bao)(bao)護(hu)范圍可(ke)(ke)調，而微(wei)斷(duan)的(de)過載(zai)保(bao)(bao)護(hu)為定值，所(suo)以(yi)只有當微(wei)斷(duan)的(de)熱(re)(re)(re)(re)脫(tuo)扣電(dian)(dian)(dian)(dian)流正好適用于(yu)被(bei)保(bao)(bao)護(hu)的(de)電(dian)(dian)(dian)(dian)容器(qi)(qi)，才可(ke)(ke)以(yi)用微(wei)斷(duan)來代替熱(re)(re)(re)(re)繼(ji)電(dian)(dian)(dian)(dian)器(qi)(qi)。一次方(fang)案也簡(jian)化(hua)為：刀熔(rong)開(kai)關→微(wei)型(xing)(xing)斷(duan)路器(qi)(qi)→接(jie)(jie)觸器(qi)(qi)→（電(dian)(dian)(dian)(dian)抗器(qi)(qi)）→電(dian)(dian)(dian)(dian)容器(qi)(qi)。此方(fang)案應(ying)該(gai)根據被(bei)保(bao)(bao)護(hu)器(qi)(qi)件（電(dian)(dian)(dian)(dian)容器(qi)(qi)）合(he)(he)理(li)(li)選擇保(bao)(bao)護(hu)器(qi)(qi)件（微(wei)型(xing)(xing)斷(duan)路器(qi)(qi)，接(jie)(jie)觸器(qi)(qi)）微(wei)斷(duan)應(ying)滿足分(fen)斷(duan)要求，采用D型(xing)(xing)或(huo)更高(gao)分(fen)斷(duan)能力(li)，熱(re)(re)(re)(re)脫(tuo)扣整定與被(bei)保(bao)(bao)護(hu)器(qi)(qi)件相(xiang)符。但應(ying)注意(yi)(yi)的(de)是，熱(re)(re)(re)(re)脫(tuo)扣動(dong)作后，需人工把開(kai)關合(he)(he)上，對(dui)于(yu)無人值守的(de)配電(dian)(dian)(dian)(dian)室，補償(chang)(chang)柜自動(dong)補償(chang)(chang)的(de)意(yi)(yi)義將大(da)打折(zhe)扣。所(suo)以(yi)微(wei)斷(duan)熱(re)(re)(re)(re)脫(tuo)扣代替熱(re)(re)(re)(re)繼(ji)電(dian)(dian)(dian)(dian)器(qi)(qi)不合(he)(he)理(li)(li)。

五、XD1電抗器與濾波(bo)電抗器一(yi)樣嗎?

XD1電(dian)抗(kang)器(qi)全(quan)稱(cheng)為XD1限流型電(dian)抗(kang)器(qi)，采用(yong)不飽和聚酯樹脂澆注成(cheng)型，用(yong)于無功功率補償裝(zhuang)置(zhi)中作為限制低壓電(dian)容器(qi)的(de)合閘涌流和增加合閘開關的(de)開斷能(neng)(neng)力(li)。濾波電(dian)抗(kang)器(qi)在低壓無功補償成(cheng)套(tao)裝(zhuang)置(zhi)中，與并聯電(dian)容器(qi)串聯使用(yong)，確(que)保裝(zhuang)置(zhi)在諧波嚴重的(de)場合能(neng)(neng)正(zheng)常安全(quan)地(di)運(yun)行。

電(dian)(dian)(dian)(dian)容柜補償時電(dian)(dian)(dian)(dian)容和(he)負載是(shi)并聯連接(jie)的(de)(de)，電(dian)(dian)(dian)(dian)容就(jiu)和(he)電(dian)(dian)(dian)(dian)庫一樣，當負載增大時，由于電(dian)(dian)(dian)(dian)源存在內(nei)阻，電(dian)(dian)(dian)(dian)源輸出(chu)電(dian)(dian)(dian)(dian)壓就(jiu)會下(xia)降(jiang)，由于電(dian)(dian)(dian)(dian)容的(de)(de)兩端要維持原來的(de)(de)電(dian)(dian)(dian)(dian)壓，也就(jiu)是(shi)電(dian)(dian)(dian)(dian)容內(nei)的(de)(de)電(dian)(dian)(dian)(dian)流要流出(chu)一部(bu)分(fen)，延緩了(le)電(dian)(dian)(dian)(dian)壓的(de)(de)下(xia)降(jiang)趨勢，就(jiu)是(shi)電(dian)(dian)(dian)(dian)容補償原理(li)。

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