電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)(de)質量(liang)問題固然對(dui)UPS至關(guan)重(zhong)要(yao)，但(dan)(dan)充(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)的(de)(de)(de)(de)(de)充(chong)電(dian)(dian)(dian)(dian)(dian)質量(liang)在(zai)(zai)很大(da)程(cheng)度上影響(xiang)著電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)(de)質量(liang)，其(qi)原因(yin)在(zai)(zai)前(qian)面已(yi)經提及。尤其(qi)是(shi)(shi)電(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)的(de)(de)(de)(de)(de)精度一定(ding)要(yao)保(bao)證，因(yin)為(wei)(wei)浮充(chong)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)的(de)(de)(de)(de)(de)過(guo)高或過(guo)低都會(hui)影響(xiang)電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)(de)壽(shou)(shou)命(ming)(ming)，圖(tu)1表示的(de)(de)(de)(de)(de)是(shi)(shi)MSE電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)(de)充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)與壽(shou)(shou)命(ming)(ming)的(de)(de)(de)(de)(de)關(guan)系(xi)，該實驗(yan)是(shi)(shi)在(zai)(zai)40oC的(de)(de)(de)(de)(de)條件下(xia)加速進行的(de)(de)(de)(de)(de)。由此曲線(xian)可(ke)以(yi)看出，在(zai)(zai)這(zhe)里的(de)(de)(de)(de)(de)浮充(chong)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)推薦(jian)值是(shi)(shi)2.25V/cell，高于(yu)這(zhe)個值或低于(yu)這(zhe)個值都會(hui)縮短(duan)(duan)電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)(de)壽(shou)(shou)命(ming)(ming)。比如(ru)浮充(chong)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)是(shi)(shi)2.225V/cell時(shi)，壽(shou)(shou)命(ming)(ming)將縮短(duan)(duan)5%，而(er)浮充(chong)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)上升到(dao)2.4V/cell時(shi)，壽(shou)(shou)命(ming)(ming)就(jiu)(jiu)縮短(duan)(duan)了40%。由此可(ke)見，維持精確的(de)(de)(de)(de)(de)浮充(chong)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)值是(shi)(shi)如(ru)何重(zhong)要(yao)。但(dan)(dan)為(wei)(wei)了使電(dian)(dian)(dian)(dian)(dian)池(chi)長期使用后還能(neng)保(bao)證各電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)的(de)(de)(de)(de)(de)平衡，采用的(de)(de)(de)(de)(de)措施是(shi)(shi)均衡充(chong)電(dian)(dian)(dian)(dian)(dian)，而(er)均衡充(chong)電(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)也大(da)都是(shi)(shi)2.4V/cell，這(zhe)就(jiu)(jiu)和上面的(de)(de)(de)(de)(de)曲線(xian)發生了矛盾，實際(ji)上事情就(jiu)(jiu)是(shi)(shi)這(zhe)樣，有得(de)就(jiu)(jiu)有失，所以(yi)電(dian)(dian)(dian)(dian)(dian)池(chi)在(zai)(zai)均衡充(chong)電(dian)(dian)(dian)(dian)(dian)時(shi)一定(ding)要(yao)控制好時(shi)間，以(yi)盡量(liang)延長電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)(de)服務壽(shou)(shou)命(ming)(ming)。

　　圖1 MSE電池的充電電壓與壽命的關系（40oC加速實驗(yan)）

1.恒壓充電

　　所謂恒壓充(chong)(chong)電(dian)(dian)(dian)就是(shi)用一穩壓源給(gei)電(dian)(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)(dian)，這種方法簡(jian)單易行，也(ye)能夠(gou)保(bao)證電(dian)(dian)(dian)池(chi)的精確浮充(chong)(chong)電(dian)(dian)(dian)壓。但(dan)若(ruo)在電(dian)(dian)(dian)池(chi)深度放電(dian)(dian)(dian)后充(chong)(chong)電(dian)(dian)(dian)時，由(you)于電(dian)(dian)(dian)池(chi)的內(nei)阻(zu)相(xiang)對而言仍然(ran)很低，就會有很大的充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流使(shi)(shi)(shi)化學反(fan)應(ying)劇烈(lie)地進行，從而產(chan)生大量的氣(qi)體，由(you)于還(huan)原反(fan)應(ying)來不及進行，使(shi)(shi)(shi)殼(ke)內(nei)氣(qi)壓迅(xun)速增加(jia)，沖開排氣(qi)閥(fa)將氣(qi)體逸出，加(jia)速了(le)電(dian)(dian)(dian)解液的干涸，縮短(duan)了(le)電(dian)(dian)(dian)池(chi)的壽命；若(ruo)排氣(qi)閥(fa)因故障而無法打開，就會使(shi)(shi)(shi)電(dian)(dian)(dian)池(chi)的外殼(ke)鼓脹或破裂(lie)。隨著電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓的升高，充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流逐漸減小，其減小的規(gui)律是(shi)：

 　　                                             （1）

式中   ICH――電(dian)(dian)池(chi)的充電(dian)(dian)電(dian)(dian)流，A；

       E――充(chong)電(dian)器(qi)的輸出電(dian)壓(ya)，V；

       UGB――電池電壓(ya)，V；

       RGB――電池的內阻，Ω。

　　上(shang)式中(zhong)有三個變量ICH、UGB、RGB，充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流ICH隨(sui)著(zhu)充(chong)(chong)電(dian)(dian)(dian)(dian)過(guo)(guo)(guo)程的(de)進行(xing)(xing)而(er)(er)減小，電(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)壓(ya)UGB隨(sui)著(zhu)充(chong)(chong)電(dian)(dian)(dian)(dian)過(guo)(guo)(guo)程的(de)進行(xing)(xing)而(er)(er)升高，而(er)(er)電(dian)(dian)(dian)(dian)池內阻RGB隨(sui)著(zhu)充(chong)(chong)電(dian)(dian)(dian)(dian)過(guo)(guo)(guo)程的(de)進行(xing)(xing)而(er)(er)減小。這就決定(ding)了充(chong)(chong)電(dian)(dian)(dian)(dian)過(guo)(guo)(guo)程的(de)非線性。尤(you)其是(shi)在接近(jin)浮充(chong)(chong)電(dian)(dian)(dian)(dian)壓(ya)值(zhi)(zhi)時(shi)，使充(chong)(chong)電(dian)(dian)(dian)(dian)變的(de)非常緩慢，從理論上(shang)講，充(chong)(chong)電(dian)(dian)(dian)(dian)到額定(ding)浮充(chong)(chong)值(zhi)(zhi)的(de)時(shi)間是(shi)無窮大。

　　這(zhe)種充電方(fang)式在早期的小容(rong)量UPS中(zhong)曾一度使用過，因(yin)出(chu)現了好多(duo)故障(zhang)，目(mu)前一般不用了。{{分頁}}

2.恒流充電

　　恒流充(chong)(chong)(chong)(chong)電(dian)(dian)的(de)(de)好處在(zai)于(yu)(yu)：一(yi)方(fang)(fang)面(mian)可(ke)以限(xian)制充(chong)(chong)(chong)(chong)電(dian)(dian)電(dian)(dian)流，避免了(le)由于(yu)(yu)上述的(de)(de)劇烈反應而導致的(de)(de)副作(zuo)用；另(ling)一(yi)方(fang)(fang)面(mian)，可(ke)使充(chong)(chong)(chong)(chong)電(dian)(dian)直線進行(xing)，加快了(le)充(chong)(chong)(chong)(chong)電(dian)(dian)的(de)(de)速度(du)，也(ye)(ye)可(ke)避免接(jie)近(jin)浮(fu)充(chong)(chong)(chong)(chong)值(zhi)時(shi)(shi)的(de)(de)過(guo)于(yu)(yu)緩慢的(de)(de)過(guo)程(cheng)。這種方(fang)(fang)法也(ye)(ye)有(you)(you)不(bu)足之處，因(yin)為隨著充(chong)(chong)(chong)(chong)電(dian)(dian)過(guo)程(cheng)的(de)(de)進行(xing)，未經反應的(de)(de)物(wu)質會(hui)越(yue)來越(yue)少，如果(guo)仍用充(chong)(chong)(chong)(chong)電(dian)(dian)初期的(de)(de)電(dian)(dian)流注入，由于(yu)(yu)反應物(wu)質的(de)(de)缺乏(fa)就會(hui)用水(shui)(shui)的(de)(de)電(dian)(dian)解來填補(bu)，這又(you)會(hui)導致水(shui)(shui)的(de)(de)電(dian)(dian)離物(wu)氫和氧的(de)(de)快速蒸(zheng)發，從而也(ye)(ye)縮短了(le)電(dian)(dian)池(chi)的(de)(de)服務壽命。因(yin)此(ci)也(ye)(ye)有(you)(you)的(de)(de)提出在(zai)電(dian)(dian)池(chi)浮(fu)充(chong)(chong)(chong)(chong)電(dian)(dian)到“一(yi)定(ding)值(zhi)”時(shi)(shi)將充(chong)(chong)(chong)(chong)電(dian)(dian)電(dian)(dian)流減(jian)半(ban)。就是這個“一(yi)定(ding)值(zhi)”也(ye)(ye)很(hen)難掌(zhang)握(wo)，尤(you)其是接(jie)近(jin)額定(ding)浮(fu)充(chong)(chong)(chong)(chong)電(dian)(dian)壓值(zhi)時(shi)(shi)，如果(guo)仍用這個即使是減(jian)了(le)半(ban)的(de)(de)電(dian)(dian)流強行(xing)灌入，也(ye)(ye)會(hui)加快電(dian)(dian)解水(shui)(shui)的(de)(de)進程(cheng)，縮短電(dian)(dian)池(chi)的(de)(de)壽命。因(yin)此(ci)這個界限(xian)也(ye)(ye)難于(yu)(yu)劃分(fen)和掌(zhang)握(wo)。此(ci)種方(fang)(fang)法有(you)(you)的(de)(de)在(zai)均衡充(chong)(chong)(chong)(chong)電(dian)(dian)中使用。

3.恒流恒壓充電

　　鑒于(yu)(yu)上述兩(liang)種充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)方(fang)(fang)式(shi)的優(you)點和不足，于(yu)(yu)是(shi)(shi)就推(tui)出(chu)了(le)將二者優(you)點集合與一體的所(suo)謂(wei)恒流(liu)恒壓(ya)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)方(fang)(fang)式(shi)，實際(ji)上是(shi)(shi)限(xian)(xian)流(liu)恒壓(ya)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)方(fang)(fang)式(shi)。在(zai)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)初期由于(yu)(yu)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)有可能非常(chang)大(da)，所(suo)以這時的充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)路將該電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)限(xian)(xian)制在(zai)一個(ge)規定(ding)值(zhi)(zhi)，使之能最大(da)限(xian)(xian)度地(di)保證既能快速充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)，又能保證充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)過程的安全(quan)。這一段的充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)幾乎是(shi)(shi)線性的，隨著充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)過程的進行，大(da)約(yue)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)至80%～90%電(dian)(dian)(dian)(dian)(dian)(dian)池容量時，充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)開(kai)始小于(yu)(yu)限(xian)(xian)流(liu)值(zhi)(zhi)，其電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)的變化開(kai)始遵從式(shi)(1)。目前UPS中的充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)大(da)都采用這種方(fang)(fang)式(shi)。

4.充電電路

　　(1)概述  UPS中(zhong)(zhong)電(dian)(dian)池(chi)的(de)充(chong)電(dian)(dian)電(dian)(dian)路(lu)不外乎兩種：降壓(ya)(ya)(ya)充(chong)電(dian)(dian)電(dian)(dian)路(lu)和(he)升壓(ya)(ya)(ya)充(chong)電(dian)(dian)電(dian)(dian)路(lu)。在(zai)一(yi)些小容(rong)量(liang)UPS中(zhong)(zhong)，由于電(dian)(dian)池(chi)組(zu)(zu)電(dian)(dian)壓(ya)(ya)(ya)比較低，故多用降壓(ya)(ya)(ya)電(dian)(dian)路(lu)，比如Smart、Matrix和(he)Symmetra等系(xi)列(lie)UPS中(zhong)(zhong)，電(dian)(dian)池(chi)組(zu)(zu)額定電(dian)(dian)壓(ya)(ya)(ya)最高也就是(shi)(shi)120V，浮(fu)充(chong)電(dian)(dian)壓(ya)(ya)(ya)也小于140V，由單相220V交流(liu)電(dian)(dian)壓(ya)(ya)(ya)足可(ke)以(yi)得到此(ci)值；為(wei)了提高充(chong)電(dian)(dian)器的(de)效率和(he)降低功耗，充(chong)電(dian)(dian)器多采用稱為(wei)Buck電(dian)(dian)路(lu)的(de)高頻PWM方案(an)，這在(zai)前(qian)面已有介紹。在(zai)中(zhong)(zhong)大容(rong)量(liang)的(de)UPS系(xi)統中(zhong)(zhong)，輸入多是(shi)(shi)三相電(dian)(dian)壓(ya)(ya)(ya)，又由于輸入整流(liu)器采用了相控(kong)的(de)晶(jing)閘(zha)管方案(an)，本身的(de)輸出電(dian)(dian)壓(ya)(ya)(ya)穩(wen)定度已達到了蓄電(dian)(dian)池(chi)的(de)要求(qiu)，故電(dian)(dian)池(chi)的(de)充(chong)電(dian)(dian)功能(neng)統一(yi)由整流(liu)器負(fu)擔，這也是(shi)(shi)一(yi)個降壓(ya)(ya)(ya)充(chong)電(dian)(dian)電(dian)(dian)路(lu)。

　　只有(you)一部分小容量UPS采用(yong)了高壓(ya)(ya)(ya)電(dian)(dian)(dian)池(chi)組，比如單相220V輸入(ru)的Imel 7.5kVA UPS就采用(yong)了384V的電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓(ya)(ya)(ya)，遠遠超(chao)過了220V交流電(dian)(dian)(dian)壓(ya)(ya)(ya)幅值310V，因此不提高電(dian)(dian)(dian)壓(ya)(ya)(ya)就無(wu)法滿足電(dian)(dian)(dian)池(chi)組的充電(dian)(dian)(dian)要求。所以機器中就采用(yong)了稱為Boost的升壓(ya)(ya)(ya)PWM電(dian)(dian)(dian)路。

　　一(yi)般UPS電(dian)(dian)(dian)(dian)(dian)(dian)源的(de)(de)后(hou)備時(shi)(shi)間(jian)大都在(zai)10min左右，充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器的(de)(de)設計也與此(ci)對應(ying)。如(ru)遇(yu)有長(chang)延時(shi)(shi)的(de)(de)要(yao)(yao)求，雖(sui)然(ran)(ran)增(zeng)(zeng)加了(le)(le)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)可以滿(man)足其放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)能(neng)力，但充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)速度就(jiu)遠達不到目的(de)(de)了(le)(le)。比(bi)如(ru)一(yi)般UPS內含10min電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)時(shi)(shi)，放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)后(hou)重(zhong)新充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)時(shi)(shi)間(jian)為10～12h。當有的(de)(de)用(yong)戶提(ti)出了(le)(le)8h要(yao)(yao)求時(shi)(shi)，電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)容量(liang)增(zeng)(zeng)加到原來的(de)(de)48倍！若(ruo)充(chong)足如(ru)此(ci)大的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)顯然(ran)(ran)不能(neng)靠UPS的(de)(de)內部充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器了(le)(le)。于是就(jiu)提(ti)出了(le)(le)外加充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器的(de)(de)要(yao)(yao)求。

　　(2)UPS外加(jia)(jia)充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)(qi)的(de)(de)(de)(de)(de)配置原則  UPS外加(jia)(jia)充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)(qi)的(de)(de)(de)(de)(de)配置原則首先是(shi)(shi)(shi)要(yao)和UPS隔離，其次(ci)才是(shi)(shi)(shi)電(dian)(dian)(dian)(dian)磁兼(jian)容指(zhi)標要(yao)和UPS相適應。以往市(shi)場(chang)上的(de)(de)(de)(de)(de)商(shang)品充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)(qi)雖然也(ye)考慮(lv)了(le)隔離問題，并且(qie)也(ye)采取了(le)措施，但由于措施不(bu)(bu)利，也(ye)不(bu)(bu)乏導(dao)致(zhi)UPS故(gu)(gu)障(zhang)的(de)(de)(de)(de)(de)例子(zi)。圖(tu)2就(jiu)是(shi)(shi)(shi)一(yi)(yi)般外加(jia)(jia)充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)(qi)隔離措施圖(tu)，實(shi)際上所謂的(de)(de)(de)(de)(de)隔離措施就(jiu)是(shi)(shi)(shi)一(yi)(yi)只二極管(guan)。GB1是(shi)(shi)(shi)UPS內部電(dian)(dian)(dian)(dian)池組，GB2是(shi)(shi)(shi)外加(jia)(jia)長延(yan)時(shi)電(dian)(dian)(dian)(dian)池組，而往往由于外加(jia)(jia)電(dian)(dian)(dian)(dian)池組的(de)(de)(de)(de)(de)容量遠大于內部電(dian)(dian)(dian)(dian)池組，一(yi)(yi)般將GB1省(sheng)掉(diao)了(le)，無論是(shi)(shi)(shi)省(sheng)掉(diao)還(huan)是(shi)(shi)(shi)不(bu)(bu)省(sheng)掉(diao)，都(dou)有(you)一(yi)(yi)個(ge)不(bu)(bu)變的(de)(de)(de)(de)(de)事實(shi)，即UPS內部充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)(qi)和外加(jia)(jia)充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)(qi)的(de)(de)(de)(de)(de)直接(jie)并聯(lian)。為了(le)隔離相互(hu)間的(de)(de)(de)(de)(de)影響，多數外加(jia)(jia)充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)(qi)多在其輸出正(zheng)端串聯(lian)了(le)一(yi)(yi)只正(zheng)向二極管(guan)D。這樣(yang)做的(de)(de)(de)(de)(de)結果(guo)是(shi)(shi)(shi)隔離了(le)UPS對(dui)充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)(qi)的(de)(de)(de)(de)(de)影響，保證(zheng)了(le)它不(bu)(bu)受(shou)其干(gan)擾，但沒(mei)有(you)消除充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)(qi)對(dui)UPS的(de)(de)(de)(de)(de)干(gan)擾。而且(qie)最關鍵的(de)(de)(de)(de)(de)就(jiu)是(shi)(shi)(shi)怕外加(jia)(jia)充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)(qi)對(dui)UPS的(de)(de)(de)(de)(de)干(gan)擾。當外加(jia)(jia)充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)(qi)充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓因失控而突然增高時(shi)，它就(jiu)會通過二極管(guan)去干(gan)擾UPS，如(ru)果(guo)該外加(jia)(jia)充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)(qi)的(de)(de)(de)(de)(de)輸出電(dian)(dian)(dian)(dian)壓是(shi)(shi)(shi)由市(shi)電(dian)(dian)(dian)(dian)直接(jie)整流(liu)后通過開關管(guan)斬波(PWM)而來，這就(jiu)將市(shi)電(dian)(dian)(dian)(dian)直接(jie)接(jie)入UPS直流(liu)電(dian)(dian)(dian)(dian)路，就(jiu)會導(dao)致(zhi)故(gu)(gu)障(zhang)。當然，此(ci)類故(gu)(gu)障(zhang)不(bu)(bu)會多見，但導(dao)致(zhi)UPS冒煙的(de)(de)(de)(de)(de)例子(zi)已經有(you)過。這種明顯存在隱患的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)路一(yi)(yi)定要(yao)謹用。

　　圖2 一般外加(jia)充(chong)電(dian)器隔離措施圖

　　為了完全(quan)隔離相互間的干擾，圖3的外加充電(dian)器完全(quan)隔離方案是可取的，并在長期的實踐運行中得到了證明，既安全(quan)又可靠。{{分頁}}

　　圖3 外加充(chong)電(dian)器完全隔離方案原理圖

　　①外加充電(dian)器完全(quan)隔(ge)離方案設(she)計(ji)思(si)想(xiang)：

　　a.充分保證(zheng)UPS電路的(de)完(wan)整性，即該方案不動UPS的(de)一(yi)點一(yi)線，不從UPS機內(nei)引出任何附加的(de)信號線。按照UPS正(zheng)常的(de)要求(qiu)，只(zhi)從UPS的(de)輸出接線端子做正(zheng)常連接。

　　b.在(zai)外(wai)加(jia)(jia)充電器(qi)(qi)與UPS電池之間(jian)加(jia)(jia)接一個簡單的(de)三端雙向互投(tou)機(ji)(ji)構，如圖(tu)3所示，用一個中間(jian)繼電器(qi)(qi)J（或接觸器(qi)(qi)甚至雙投(tou)手(shou)動開關），將(jiang)該機(ji)(ji)構的(de)中間(jian)臂3接外(wai)加(jia)(jia)電池組(zu)GB2的(de)正極，繼電器(qi)(qi)線(xian)包J跨接在(zai)UPS市電輸入線(xian)上。

　　c.當市電(dian)正(zheng)常供電(dian)時(shi)(shi)(shi)，由于繼(ji)電(dian)器線包J被激勵(li)而(er)將觸點(dian)臂3由常閉(bi)觸點(dian)1打向2，此(ci)時(shi)(shi)(shi)正(zheng)好是外(wai)加充電(dian)器正(zheng)常輸出(chu)充電(dian)時(shi)(shi)(shi)期(qi)，GB2被正(zheng)常充電(dian)。可以看出(chu)，此(ci)時(shi)(shi)(shi)UPS和外(wai)加充電(dian)器是完全(quan)隔離(li)的，并且(qie)UPS的充電(dian)器僅(jin)僅(jin)給自己的電(dian)池GB1充電(dian)，保(bao)證(zheng)了其原有的一切充電(dian)功能(neng)。

　　d.當市(shi)電(dian)(dian)斷(duan)電(dian)(dian)時(shi)，繼電(dian)(dian)器線(xian)包(bao)J被釋放，中間(jian)臂3由(you)2回到1，將(jiang)外(wai)加(jia)電(dian)(dian)池組GB2并(bing)聯在GB1上，形成了(le)純(chun)電(dian)(dian)池組的(de)并(bing)聯，也就達到了(le)大容(rong)量電(dian)(dian)池長延時(shi)放電(dian)(dian)的(de)目的(de)。

　　e.市電(dian)恢(hui)復(fu)時，繼電(dian)器(qi)又回(hui)到“3-2”狀態。這里可(ke)能(neng)有這樣(yang)一個問題：市電(dian)恢(hui)復(fu)時，由于繼電(dian)器(qi)動作存在(zai)惰(duo)性，有可(ke)能(neng)外加電(dian)池組GB2不(bu)(bu)能(neng)及(ji)時斷開，將會(hui)(hui)造成UPS內部(bu)充電(dian)器(qi)同時為兩組電(dian)池充電(dian)的局(ju)面，會(hui)(hui)不(bu)(bu)會(hui)(hui)因(yin)充電(dian)電(dian)流太大而(er)導(dao)致(zhi)故障呢？回(hui)答是否定(ding)的。因(yin)為所有在(zai)線(xian)式(shi)UPS的充電(dian)器(qi)都是限流溫壓式(shi)的，所以不(bu)(bu)會(hui)(hui)過流。

　　上面只是給出了(le)一(yi)個原(yuan)理方(fang)案，實際結構還要復雜一(yi)些。不(bu)過，用這個原(yuan)理進行(xing)隔離(li)已經足夠了(le)。

　　關于(yu)外(wai)加(jia)充(chong)電(dian)(dian)器的(de)(de)(de)(de)(de)(de)電(dian)(dian)磁兼容問(wen)題也不可忽視，由于(yu)現代UPS的(de)(de)(de)(de)(de)(de)用(yong)(yong)戶大都集通(tong)信(xin)和大量的(de)(de)(de)(de)(de)(de)數據傳(chuan)輸為(wei)一(yi)(yi)體，尤其(qi)牽涉到無線(xian)通(tong)信(xin)，就更要求(qiu)供電(dian)(dian)系(xi)統不能(neng)對用(yong)(yong)電(dian)(dian)系(xi)統有任何干(gan)擾(rao)。因此，一(yi)(yi)般(ban)UPS系(xi)統都要通(tong)過一(yi)(yi)定的(de)(de)(de)(de)(de)(de)電(dian)(dian)磁兼容標準，如EN50091-2等(deng)。然而一(yi)(yi)般(ban)市面上(shang)的(de)(de)(de)(de)(de)(de)外(wai)加(jia)充(chong)電(dian)(dian)器很(hen)少(shao)注意到這些問(wen)題，恰(qia)恰(qia)PWM開關電(dian)(dian)源就是(shi)(shi)(shi)無線(xian)通(tong)信(xin)的(de)(de)(de)(de)(de)(de)敏感干(gan)擾(rao)源，因此不得不向其(qi)提出相(xiang)應的(de)(de)(de)(de)(de)(de)要求(qiu)。有時為(wei)了安(an)全(quan)起(qi)見，采(cai)用(yong)(yong)原(yuan)理上(shang)的(de)(de)(de)(de)(de)(de)無干(gan)擾(rao)電(dian)(dian)路是(shi)(shi)(shi)必要的(de)(de)(de)(de)(de)(de)。圖4表(biao)示(shi)的(de)(de)(de)(de)(de)(de)就是(shi)(shi)(shi)這樣一(yi)(yi)種無干(gan)擾(rao)充(chong)電(dian)(dian)器電(dian)(dian)路原(yuan)理圖，這是(shi)(shi)(shi)一(yi)(yi)個(ge)典型的(de)(de)(de)(de)(de)(de)具有限流穩壓功能(neng)的(de)(de)(de)(de)(de)(de)充(chong)電(dian)(dian)器。

　　圖4 無干擾充電器電路原理圖{{分頁}}

　　②無干(gan)擾(rao)充(chong)電器電路特點：

　　a.電(dian)(dian)(dian)(dian)路結構簡單、成熟、可(ke)(ke)靠。主回路只(zhi)有電(dian)(dian)(dian)(dian)容器(qi)(qi)和普通(tong)整流器(qi)(qi)，這種傳統(tong)器(qi)(qi)件的(de)(de)制造歷史(shi)很長(chang)，已達到很高的(de)(de)可(ke)(ke)靠性(xing)指標(biao)；輔助充電(dian)(dian)(dian)(dian)器(qi)(qi)也(ye)是歷史(shi)很長(chang)的(de)(de)、性(xing)能指標(biao)非常好的(de)(de)傳統(tong)電(dian)(dian)(dian)(dian)路，輸(shu)出電(dian)(dian)(dian)(dian)壓(ya)(ya)精度很容易做到1%，輸(shu)出電(dian)(dian)(dian)(dian)壓(ya)(ya)紋(wen)波做到<5mV則輕(qing)而易舉(ju)；測量與控制電(dian)(dian)(dian)(dian)路都(dou)(dou)是由傳統(tong)的(de)(de)比較器(qi)(qi)、運算(suan)放(fang)大器(qi)(qi)之類的(de)(de)組件構成，可(ke)(ke)靠性(xing)當然(ran)更無問(wen)題；執(zhi)行器(qi)(qi)件是一只(zhi)繼(ji)電(dian)(dian)(dian)(dian)器(qi)(qi)，一般觸點的(de)(de)動作次(ci)數(shu)都(dou)(dou)在106次(ci)以上。

　　b.電(dian)(dian)路(lu)(lu)(lu)工(gong)作原理簡單、實(shi)用。充(chong)電(dian)(dian)器(qi)的(de)(de)(de)兩個主要功能就(jiu)(jiu)是(shi)限(xian)流(liu)充(chong)電(dian)(dian)和穩壓浮(fu)充(chong)。該(gai)電(dian)(dian)路(lu)(lu)(lu)中的(de)(de)(de)限(xian)流(liu)是(shi)靠(kao)一只(zhi)電(dian)(dian)容(rong)(rong)器(qi)來完成的(de)(de)(de)，既(ji)無(wu)電(dian)(dian)流(liu)傳感器(qi)又無(wu)反饋控制機構(gou)(gou)，僅(jin)僅(jin)靠(kao)電(dian)(dian)容(rong)(rong)本(ben)身的(de)(de)(de)電(dian)(dian)壓自調整就(jiu)(jiu)實(shi)現了(le)(le)限(xian)流(liu)功能；大(da)電(dian)(dian)流(liu)充(chong)電(dian)(dian)和高精度浮(fu)充(chong)溫壓分別進(jin)行，就(jiu)(jiu)大(da)大(da)簡化了(le)(le)電(dian)(dian)路(lu)(lu)(lu)，指標(biao)也容(rong)(rong)易做(zuo)(zuo)得好(hao)；用繼電(dian)(dian)器(qi)做(zuo)(zuo)主充(chong)電(dian)(dian)電(dian)(dian)路(lu)(lu)(lu)和輔助充(chong)電(dian)(dian)器(qi)（線性穩壓器(qi)）的(de)(de)(de)切換機構(gou)(gou)而不考慮0切換，這正是(shi)利用了(le)(le)電(dian)(dian)路(lu)(lu)(lu)對該(gai)指標(biao)不加考慮的(de)(de)(de)特點。

　　c.整(zheng)個電路(lu)的(de)工作狀態(tai)都是線(xian)性的(de)，無產生高頻干擾的(de)機(ji)構和(he)過程(cheng)。主(zhu)回路(lu)的(de)電容器和(he)普通整(zheng)流(liu)器都自然地(di)工作于50Hz，線(xian)性穩壓器從小信號(hao)到大信號(hao)都是典型的(de)線(xian)性工作狀態(tai)，測量(liang)與控制電路(lu)也僅僅是對直流(liu)電平的(de)線(xian)性轉換。

　　因此，整個電(dian)路從(cong)原(yuan)理上就杜絕(jue)了高頻(pin)干(gan)擾(rao)的發生。不(bu)(bu)過這種(zhong)電(dian)路比同容量的PWM充(chong)電(dian)器體積要大(da)一些(xie)。因此，在那些(xie)對干(gan)擾(rao)指標要求不(bu)(bu)太嚴格的地方，PWM充(chong)電(dian)器還(huan)是得到了廣泛的應(ying)用。

　　(3)雙電池組充電器：

　　①升壓（Boost）充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)路。單(dan)電(dian)(dian)(dian)(dian)(dian)子器件的(de)發展(zhan)促(cu)進了(le)UPS技術的(de)發展(zhan)，近年來高(gao)頻機UPS的(de)出現(xian)(xian)，使該類產品的(de)逆(ni)變器輸出省去了(le)笨(ben)重的(de)隔離變壓器，同(tong)時將電(dian)(dian)(dian)(dian)(dian)池由一(yi)(yi)組(zu)增(zeng)加到兩組(zu)，但容量不(bu)變，比如(ru)原來用一(yi)(yi)組(zu)電(dian)(dian)(dian)(dian)(dian)池時是100Ah，而現(xian)(xian)在(zai)變成(cheng)了(le)兩組(zu)50Ah。如(ru)圖5所示的(de)GB1和GB2。兩組(zu)電(dian)(dian)(dian)(dian)(dian)池串聯連接，每組(zu)電(dian)(dian)(dian)(dian)(dian)池標稱電(dian)(dian)(dian)(dian)(dian)壓一(yi)(yi)般為384V，兩組(zu)串聯總電(dian)(dian)(dian)(dian)(dian)壓為768V，若(ruo)按(an)照(zhao)2.25V/單(dan)元的(de)標準充電(dian)(dian)(dian)(dian)(dian)，兩組(zu)電(dian)(dian)(dian)(dian)(dian)池的(de)浮充電(dian)(dian)(dian)(dian)(dian)壓就(jiu)需(xu)：