電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)(de)質(zhi)量(liang)(liang)問題固然對UPS至關(guan)重要，但充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器的(de)(de)(de)(de)(de)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)質(zhi)量(liang)(liang)在(zai)很大程度上(shang)影響(xiang)著(zhu)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)(de)質(zhi)量(liang)(liang)，其(qi)原因(yin)在(zai)前面已經提及。尤其(qi)是(shi)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)的(de)(de)(de)(de)(de)精度一(yi)定(ding)要保證，因(yin)為浮充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)的(de)(de)(de)(de)(de)過(guo)(guo)高或過(guo)(guo)低都(dou)會(hui)影響(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)(de)壽(shou)命(ming)，圖1表示的(de)(de)(de)(de)(de)是(shi)MSE電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)(de)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)與(yu)壽(shou)命(ming)的(de)(de)(de)(de)(de)關(guan)系，該實(shi)(shi)驗是(shi)在(zai)40oC的(de)(de)(de)(de)(de)條件下加速(su)進(jin)行的(de)(de)(de)(de)(de)。由此(ci)曲線可以看(kan)出(chu)，在(zai)這里(li)的(de)(de)(de)(de)(de)浮充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)推薦值(zhi)是(shi)2.25V/cell，高于這個(ge)值(zhi)或低于這個(ge)值(zhi)都(dou)會(hui)縮短(duan)(duan)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)(de)壽(shou)命(ming)。比如浮充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)是(shi)2.225V/cell時，壽(shou)命(ming)將縮短(duan)(duan)5%，而浮充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)上(shang)升到2.4V/cell時，壽(shou)命(ming)就(jiu)縮短(duan)(duan)了40%。由此(ci)可見，維持精確的(de)(de)(de)(de)(de)浮充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)值(zhi)是(shi)如何重要。但為了使(shi)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)長期(qi)使(shi)用(yong)后還能(neng)保證各電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)的(de)(de)(de)(de)(de)平衡(heng)，采用(yong)的(de)(de)(de)(de)(de)措施(shi)是(shi)均(jun)衡(heng)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)，而均(jun)衡(heng)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)也大都(dou)是(shi)2.4V/cell，這就(jiu)和(he)上(shang)面的(de)(de)(de)(de)(de)曲線發(fa)生了矛盾，實(shi)(shi)際(ji)上(shang)事情就(jiu)是(shi)這樣，有(you)得就(jiu)有(you)失，所以電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)在(zai)均(jun)衡(heng)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)時一(yi)定(ding)要控制好時間，以盡量(liang)(liang)延(yan)長電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)(de)服(fu)務壽(shou)命(ming)。

　　圖1 MSE電池的充電電壓(ya)與(yu)壽命的關系（40oC加速實驗）

1.恒壓充電

　　所謂恒壓充(chong)(chong)電(dian)(dian)就(jiu)是(shi)用(yong)一(yi)穩壓源給電(dian)(dian)池(chi)(chi)充(chong)(chong)電(dian)(dian)，這種方法(fa)簡單易行(xing)，也能夠保證(zheng)電(dian)(dian)池(chi)(chi)的(de)(de)精確浮充(chong)(chong)電(dian)(dian)壓。但(dan)若在電(dian)(dian)池(chi)(chi)深度(du)放電(dian)(dian)后充(chong)(chong)電(dian)(dian)時，由(you)于電(dian)(dian)池(chi)(chi)的(de)(de)內(nei)阻相對而(er)言仍(reng)然很(hen)低，就(jiu)會(hui)有很(hen)大的(de)(de)充(chong)(chong)電(dian)(dian)電(dian)(dian)流使化學反(fan)應劇烈地進(jin)行(xing)，從而(er)產生大量的(de)(de)氣體，由(you)于還原反(fan)應來(lai)不及進(jin)行(xing)，使殼內(nei)氣壓迅速增加，沖(chong)開排(pai)氣閥將氣體逸(yi)出，加速了電(dian)(dian)解液(ye)的(de)(de)干涸，縮短了電(dian)(dian)池(chi)(chi)的(de)(de)壽命；若排(pai)氣閥因故障(zhang)而(er)無(wu)法(fa)打開，就(jiu)會(hui)使電(dian)(dian)池(chi)(chi)的(de)(de)外殼鼓脹或破裂。隨(sui)著電(dian)(dian)池(chi)(chi)電(dian)(dian)壓的(de)(de)升高(gao)，充(chong)(chong)電(dian)(dian)電(dian)(dian)流逐漸減(jian)小(xiao)，其(qi)減(jian)小(xiao)的(de)(de)規律是(shi)：

 　　                                             （1）

式中   ICH――電池的充電電流，A；

       E――充(chong)電器的(de)輸出電壓(ya)，V；

       UGB――電(dian)池電(dian)壓，V；

       RGB――電池的內阻，Ω。

　　上式中有三(san)個變量ICH、UGB、RGB，充電(dian)(dian)電(dian)(dian)流ICH隨著充電(dian)(dian)過程(cheng)的(de)(de)進行(xing)而(er)減小(xiao)，電(dian)(dian)池(chi)電(dian)(dian)壓UGB隨著充電(dian)(dian)過程(cheng)的(de)(de)進行(xing)而(er)升(sheng)高，而(er)電(dian)(dian)池(chi)內阻RGB隨著充電(dian)(dian)過程(cheng)的(de)(de)進行(xing)而(er)減小(xiao)。這(zhe)就決(jue)定了(le)充電(dian)(dian)過程(cheng)的(de)(de)非線性。尤其是在(zai)接近浮(fu)充電(dian)(dian)壓值時(shi)，使充電(dian)(dian)變的(de)(de)非常緩(huan)慢，從理論上講，充電(dian)(dian)到額定浮(fu)充值的(de)(de)時(shi)間是無(wu)窮(qiong)大。

　　這種(zhong)充(chong)電方(fang)式在早(zao)期的小容量(liang)UPS中曾(ceng)一度使用過，因出現了好(hao)多故障，目前一般不用了。{{分頁}}

2.恒流充電

　　恒(heng)流(liu)充(chong)電(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)好處在(zai)(zai)于：一(yi)(yi)方面可(ke)以限(xian)制充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)，避(bi)免了由(you)于上述的(de)(de)(de)劇烈反(fan)應而導致的(de)(de)(de)副(fu)作用(yong)；另一(yi)(yi)方面，可(ke)使充(chong)電(dian)(dian)(dian)(dian)(dian)直線進(jin)(jin)行(xing)，加快了充(chong)電(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)速度(du)，也(ye)(ye)可(ke)避(bi)免接近浮(fu)充(chong)值(zhi)時的(de)(de)(de)過(guo)于緩(huan)慢的(de)(de)(de)過(guo)程。這種方法(fa)也(ye)(ye)有不足(zu)之處，因為隨(sui)著充(chong)電(dian)(dian)(dian)(dian)(dian)過(guo)程的(de)(de)(de)進(jin)(jin)行(xing)，未經反(fan)應的(de)(de)(de)物質會越來(lai)越少，如果仍用(yong)充(chong)電(dian)(dian)(dian)(dian)(dian)初期的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)流(liu)注(zhu)入，由(you)于反(fan)應物質的(de)(de)(de)缺乏就會用(yong)水的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)解來(lai)填(tian)補，這又(you)會導致水的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)離物氫和氧的(de)(de)(de)快速蒸(zheng)發，從而也(ye)(ye)縮短(duan)了電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)(de)服務壽命(ming)。因此(ci)也(ye)(ye)有的(de)(de)(de)提出(chu)在(zai)(zai)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)浮(fu)充(chong)電(dian)(dian)(dian)(dian)(dian)到“一(yi)(yi)定值(zhi)”時將充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)減(jian)半。就是(shi)這個“一(yi)(yi)定值(zhi)”也(ye)(ye)很難掌(zhang)握(wo)(wo)，尤其(qi)是(shi)接近額定浮(fu)充(chong)電(dian)(dian)(dian)(dian)(dian)壓(ya)值(zhi)時，如果仍用(yong)這個即使是(shi)減(jian)了半的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)流(liu)強行(xing)灌入，也(ye)(ye)會加快電(dian)(dian)(dian)(dian)(dian)解水的(de)(de)(de)進(jin)(jin)程，縮短(duan)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)(de)壽命(ming)。因此(ci)這個界限(xian)也(ye)(ye)難于劃(hua)分(fen)和掌(zhang)握(wo)(wo)。此(ci)種方法(fa)有的(de)(de)(de)在(zai)(zai)均(jun)衡(heng)充(chong)電(dian)(dian)(dian)(dian)(dian)中使用(yong)。

3.恒流恒壓充電

　　鑒(jian)于(yu)上(shang)述兩種(zhong)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)方式的(de)(de)優(you)點(dian)和不足，于(yu)是就推出了將二(er)者優(you)點(dian)集合(he)與一(yi)體的(de)(de)所(suo)謂恒流(liu)恒壓(ya)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)方式，實際(ji)上(shang)是限(xian)流(liu)恒壓(ya)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)方式。在(zai)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)初(chu)期由(you)于(yu)電(dian)(dian)(dian)(dian)流(liu)有(you)可能(neng)(neng)非常大(da)(da)，所(suo)以這時的(de)(de)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)路將該電(dian)(dian)(dian)(dian)流(liu)限(xian)制在(zai)一(yi)個規定值(zhi)，使之能(neng)(neng)最大(da)(da)限(xian)度地保證(zheng)既能(neng)(neng)快速(su)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)，又能(neng)(neng)保證(zheng)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)過(guo)程的(de)(de)安全。這一(yi)段的(de)(de)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)幾乎(hu)是線性的(de)(de)，隨著(zhu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)過(guo)程的(de)(de)進行(xing)，大(da)(da)約充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)至(zhi)80%～90%電(dian)(dian)(dian)(dian)池(chi)容量時，充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)開始小(xiao)于(yu)限(xian)流(liu)值(zhi)，其電(dian)(dian)(dian)(dian)流(liu)的(de)(de)變化開始遵從式(1)。目前UPS中(zhong)的(de)(de)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)大(da)(da)都采用這種(zhong)方式。

4.充電電路

　　(1)概述  UPS中(zhong)(zhong)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)路(lu)不(bu)外乎兩種：降壓(ya)(ya)(ya)充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)路(lu)和升壓(ya)(ya)(ya)充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)路(lu)。在一(yi)些小(xiao)(xiao)容量(liang)UPS中(zhong)(zhong)，由于(yu)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)組(zu)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)比(bi)較低(di)，故多用降壓(ya)(ya)(ya)電(dian)(dian)(dian)(dian)(dian)路(lu)，比(bi)如Smart、Matrix和Symmetra等(deng)系(xi)列UPS中(zhong)(zhong)，電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)組(zu)額定(ding)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)最高也就(jiu)是120V，浮(fu)充電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)也小(xiao)(xiao)于(yu)140V，由單相220V交流電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)足可(ke)以(yi)得(de)到此值；為了(le)提高充電(dian)(dian)(dian)(dian)(dian)器(qi)的(de)效率和降低(di)功(gong)(gong)耗，充電(dian)(dian)(dian)(dian)(dian)器(qi)多采(cai)用稱為Buck電(dian)(dian)(dian)(dian)(dian)路(lu)的(de)高頻PWM方(fang)案，這(zhe)(zhe)在前面已有介紹。在中(zhong)(zhong)大容量(liang)的(de)UPS系(xi)統中(zhong)(zhong)，輸入(ru)多是三相電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)，又由于(yu)輸入(ru)整(zheng)流器(qi)采(cai)用了(le)相控的(de)晶(jing)閘管方(fang)案，本(ben)身的(de)輸出(chu)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)穩定(ding)度已達到了(le)蓄電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)要求，故電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)充電(dian)(dian)(dian)(dian)(dian)功(gong)(gong)能統一(yi)由整(zheng)流器(qi)負擔，這(zhe)(zhe)也是一(yi)個(ge)降壓(ya)(ya)(ya)充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)路(lu)。

　　只有一部(bu)分小容(rong)量UPS采用了高(gao)壓(ya)(ya)(ya)(ya)電(dian)(dian)池(chi)(chi)組，比(bi)如單相220V輸入(ru)的Imel 7.5kVA UPS就(jiu)采用了384V的電(dian)(dian)池(chi)(chi)電(dian)(dian)壓(ya)(ya)(ya)(ya)，遠(yuan)遠(yuan)超過了220V交流電(dian)(dian)壓(ya)(ya)(ya)(ya)幅值310V，因此不提高(gao)電(dian)(dian)壓(ya)(ya)(ya)(ya)就(jiu)無法(fa)滿(man)足(zu)電(dian)(dian)池(chi)(chi)組的充電(dian)(dian)要求。所以機器中(zhong)就(jiu)采用了稱為Boost的升壓(ya)(ya)(ya)(ya)PWM電(dian)(dian)路。

　　一般(ban)UPS電(dian)源的(de)(de)(de)(de)后備(bei)時(shi)間(jian)大都在10min左右，充(chong)電(dian)器的(de)(de)(de)(de)設計也與(yu)此(ci)對應。如(ru)遇有長(chang)延時(shi)的(de)(de)(de)(de)要求(qiu)，雖然增加(jia)了電(dian)池可以滿足(zu)其放(fang)電(dian)的(de)(de)(de)(de)能(neng)力，但充(chong)電(dian)的(de)(de)(de)(de)速度就遠達不到目(mu)的(de)(de)(de)(de)了。比(bi)如(ru)一般(ban)UPS內含10min電(dian)池時(shi)，放(fang)電(dian)后重新充(chong)電(dian)的(de)(de)(de)(de)時(shi)間(jian)為(wei)10～12h。當有的(de)(de)(de)(de)用戶提出了8h要求(qiu)時(shi)，電(dian)池容量增加(jia)到原(yuan)來的(de)(de)(de)(de)48倍(bei)！若充(chong)足(zu)如(ru)此(ci)大的(de)(de)(de)(de)電(dian)池顯然不能(neng)靠UPS的(de)(de)(de)(de)內部(bu)充(chong)電(dian)器了。于是就提出了外加(jia)充(chong)電(dian)器的(de)(de)(de)(de)要求(qiu)。

　　(2)UPS外(wai)加(jia)(jia)(jia)(jia)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)的(de)(de)(de)(de)(de)配(pei)置原則  UPS外(wai)加(jia)(jia)(jia)(jia)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)的(de)(de)(de)(de)(de)配(pei)置原則首先是(shi)(shi)(shi)(shi)(shi)(shi)要和UPS隔(ge)離，其次才是(shi)(shi)(shi)(shi)(shi)(shi)電(dian)(dian)(dian)(dian)(dian)磁(ci)兼容指標要和UPS相適應(ying)。以往市場上的(de)(de)(de)(de)(de)商品充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)雖然也考慮了(le)隔(ge)離問題，并(bing)且也采(cai)取了(le)措(cuo)施(shi)，但(dan)由于措(cuo)施(shi)不(bu)利，也不(bu)乏導致(zhi)UPS故(gu)障的(de)(de)(de)(de)(de)例子。圖2就(jiu)(jiu)是(shi)(shi)(shi)(shi)(shi)(shi)一般(ban)外(wai)加(jia)(jia)(jia)(jia)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)隔(ge)離措(cuo)施(shi)圖，實際上所(suo)謂(wei)的(de)(de)(de)(de)(de)隔(ge)離措(cuo)施(shi)就(jiu)(jiu)是(shi)(shi)(shi)(shi)(shi)(shi)一只(zhi)二極管(guan)(guan)。GB1是(shi)(shi)(shi)(shi)(shi)(shi)UPS內(nei)部電(dian)(dian)(dian)(dian)(dian)池組(zu)，GB2是(shi)(shi)(shi)(shi)(shi)(shi)外(wai)加(jia)(jia)(jia)(jia)長延時電(dian)(dian)(dian)(dian)(dian)池組(zu)，而(er)往往由于外(wai)加(jia)(jia)(jia)(jia)電(dian)(dian)(dian)(dian)(dian)池組(zu)的(de)(de)(de)(de)(de)容量遠大于內(nei)部電(dian)(dian)(dian)(dian)(dian)池組(zu)，一般(ban)將(jiang)GB1省掉了(le)，無論是(shi)(shi)(shi)(shi)(shi)(shi)省掉還(huan)是(shi)(shi)(shi)(shi)(shi)(shi)不(bu)省掉，都有一個不(bu)變的(de)(de)(de)(de)(de)事實，即UPS內(nei)部充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)和外(wai)加(jia)(jia)(jia)(jia)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)的(de)(de)(de)(de)(de)直(zhi)接并(bing)聯。為了(le)隔(ge)離相互間的(de)(de)(de)(de)(de)影(ying)響，多數外(wai)加(jia)(jia)(jia)(jia)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)多在(zai)(zai)其輸出(chu)正(zheng)端串聯了(le)一只(zhi)正(zheng)向二極管(guan)(guan)D。這(zhe)(zhe)樣做的(de)(de)(de)(de)(de)結果是(shi)(shi)(shi)(shi)(shi)(shi)隔(ge)離了(le)UPS對(dui)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)的(de)(de)(de)(de)(de)影(ying)響，保證了(le)它不(bu)受(shou)其干(gan)(gan)擾(rao)，但(dan)沒有消(xiao)除充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)對(dui)UPS的(de)(de)(de)(de)(de)干(gan)(gan)擾(rao)。而(er)且最關(guan)鍵的(de)(de)(de)(de)(de)就(jiu)(jiu)是(shi)(shi)(shi)(shi)(shi)(shi)怕(pa)外(wai)加(jia)(jia)(jia)(jia)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)對(dui)UPS的(de)(de)(de)(de)(de)干(gan)(gan)擾(rao)。當外(wai)加(jia)(jia)(jia)(jia)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)壓(ya)因失(shi)控而(er)突然增高時，它就(jiu)(jiu)會通過二極管(guan)(guan)去干(gan)(gan)擾(rao)UPS，如(ru)果該(gai)外(wai)加(jia)(jia)(jia)(jia)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)的(de)(de)(de)(de)(de)輸出(chu)電(dian)(dian)(dian)(dian)(dian)壓(ya)是(shi)(shi)(shi)(shi)(shi)(shi)由市電(dian)(dian)(dian)(dian)(dian)直(zhi)接整流(liu)后通過開關(guan)管(guan)(guan)斬(zhan)波(PWM)而(er)來，這(zhe)(zhe)就(jiu)(jiu)將(jiang)市電(dian)(dian)(dian)(dian)(dian)直(zhi)接接入(ru)UPS直(zhi)流(liu)電(dian)(dian)(dian)(dian)(dian)路，就(jiu)(jiu)會導致(zhi)故(gu)障。當然，此類故(gu)障不(bu)會多見(jian)，但(dan)導致(zhi)UPS冒(mao)煙的(de)(de)(de)(de)(de)例子已經有過。這(zhe)(zhe)種明顯存在(zai)(zai)隱患的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)路一定要謹用。

　　圖(tu)2 一般外加(jia)充電(dian)器隔離(li)措(cuo)施圖(tu)

　　為了完全隔(ge)離(li)相互(hu)間(jian)的(de)干擾，圖3的(de)外加充(chong)電器完全隔(ge)離(li)方案是可(ke)取的(de)，并在長期的(de)實踐(jian)運行中(zhong)得到了證明，既安全又可(ke)靠(kao)。{{分頁}}

　　圖3 外加充(chong)電器完(wan)全隔(ge)離方案(an)原理圖

　　①外加充(chong)電(dian)器完全隔(ge)離方案設計思想：

　　a.充分保證UPS電路的(de)完整性，即該方案不動UPS的(de)一點一線，不從UPS機內(nei)引出任何附加(jia)的(de)信號線。按照UPS正(zheng)常的(de)要求(qiu)，只從UPS的(de)輸出接(jie)線端子做正(zheng)常連接(jie)。

　　b.在(zai)外(wai)加充(chong)電(dian)器(qi)與UPS電(dian)池之間(jian)加接一(yi)(yi)個簡(jian)單的(de)(de)三端雙向互(hu)投機構，如(ru)圖3所示，用一(yi)(yi)個中間(jian)繼電(dian)器(qi)J（或接觸器(qi)甚至(zhi)雙投手(shou)動開關），將(jiang)該(gai)機構的(de)(de)中間(jian)臂(bei)3接外(wai)加電(dian)池組GB2的(de)(de)正極(ji)，繼電(dian)器(qi)線包J跨接在(zai)UPS市電(dian)輸入(ru)線上。

　　c.當市(shi)電正常(chang)(chang)供(gong)電時(shi)，由(you)于(yu)繼電器(qi)(qi)線包(bao)J被激勵(li)而將觸點臂3由(you)常(chang)(chang)閉(bi)觸點1打向2，此(ci)時(shi)正好是(shi)外加充(chong)(chong)電器(qi)(qi)正常(chang)(chang)輸出充(chong)(chong)電時(shi)期，GB2被正常(chang)(chang)充(chong)(chong)電。可(ke)以(yi)看出，此(ci)時(shi)UPS和外加充(chong)(chong)電器(qi)(qi)是(shi)完全隔離的，并且UPS的充(chong)(chong)電器(qi)(qi)僅(jin)僅(jin)給自己的電池(chi)GB1充(chong)(chong)電，保證了其原有的一切(qie)充(chong)(chong)電功能。

　　d.當(dang)市電斷(duan)電時(shi)，繼電器線包J被釋放(fang)，中(zhong)間臂3由(you)2回到1，將外加電池(chi)(chi)組GB2并聯(lian)在GB1上，形成了(le)純電池(chi)(chi)組的(de)并聯(lian)，也就達(da)到了(le)大容量電池(chi)(chi)長延時(shi)放(fang)電的(de)目的(de)。

　　e.市(shi)電(dian)(dian)(dian)(dian)恢(hui)(hui)復時(shi)，繼電(dian)(dian)(dian)(dian)器又回(hui)到(dao)“3-2”狀態。這里可(ke)能(neng)有(you)這樣一個問(wen)題：市(shi)電(dian)(dian)(dian)(dian)恢(hui)(hui)復時(shi)，由于繼電(dian)(dian)(dian)(dian)器動(dong)作存在(zai)惰性，有(you)可(ke)能(neng)外加電(dian)(dian)(dian)(dian)池(chi)組GB2不能(neng)及(ji)時(shi)斷開，將會造成UPS內部充電(dian)(dian)(dian)(dian)器同(tong)時(shi)為兩組電(dian)(dian)(dian)(dian)池(chi)充電(dian)(dian)(dian)(dian)的(de)(de)局面，會不會因(yin)充電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流太大而導致故障呢？回(hui)答是否定的(de)(de)。因(yin)為所有(you)在(zai)線式(shi)UPS的(de)(de)充電(dian)(dian)(dian)(dian)器都是限流溫壓式(shi)的(de)(de)，所以不會過流。

　　上(shang)面只(zhi)是給出了一個(ge)原(yuan)理方(fang)案，實(shi)際結構還(huan)要復雜一些。不過，用(yong)這(zhe)個(ge)原(yuan)理進行隔離(li)已(yi)經足(zu)夠了。

　　關(guan)于外加充電(dian)(dian)器(qi)的(de)(de)電(dian)(dian)磁(ci)兼(jian)容問題(ti)也不(bu)可忽視，由(you)于現代UPS的(de)(de)用(yong)戶大(da)都集通(tong)(tong)信(xin)和大(da)量(liang)的(de)(de)數據傳輸為一(yi)(yi)體，尤其牽涉到無(wu)線通(tong)(tong)信(xin)，就(jiu)更要(yao)求供電(dian)(dian)系(xi)(xi)統(tong)(tong)不(bu)能對用(yong)電(dian)(dian)系(xi)(xi)統(tong)(tong)有任(ren)何干擾。因(yin)此，一(yi)(yi)般UPS系(xi)(xi)統(tong)(tong)都要(yao)通(tong)(tong)過一(yi)(yi)定的(de)(de)電(dian)(dian)磁(ci)兼(jian)容標準，如EN50091-2等。然而一(yi)(yi)般市面上(shang)的(de)(de)外加充電(dian)(dian)器(qi)很少(shao)注意到這(zhe)些(xie)問題(ti)，恰恰PWM開關(guan)電(dian)(dian)源(yuan)(yuan)就(jiu)是(shi)無(wu)線通(tong)(tong)信(xin)的(de)(de)敏感干擾源(yuan)(yuan)，因(yin)此不(bu)得(de)不(bu)向(xiang)其提出相應的(de)(de)要(yao)求。有時為了(le)安全起(qi)見，采用(yong)原(yuan)(yuan)理(li)上(shang)的(de)(de)無(wu)干擾電(dian)(dian)路(lu)是(shi)必(bi)要(yao)的(de)(de)。圖(tu)4表(biao)示的(de)(de)就(jiu)是(shi)這(zhe)樣一(yi)(yi)種無(wu)干擾充電(dian)(dian)器(qi)電(dian)(dian)路(lu)原(yuan)(yuan)理(li)圖(tu)，這(zhe)是(shi)一(yi)(yi)個典型的(de)(de)具有限流(liu)穩壓功能的(de)(de)充電(dian)(dian)器(qi)。

　　圖(tu)4 無干擾充(chong)電器電路原理圖(tu){{分頁}}

　　②無(wu)干擾充(chong)電器(qi)電路特點：

　　a.電(dian)(dian)(dian)路(lu)結構(gou)簡單、成熟、可靠。主回路(lu)只有電(dian)(dian)(dian)容器(qi)(qi)(qi)(qi)和(he)普通整流器(qi)(qi)(qi)(qi)，這種傳(chuan)統器(qi)(qi)(qi)(qi)件的(de)制(zhi)造歷史(shi)很長，已達到(dao)(dao)很高的(de)可靠性指標；輔助充電(dian)(dian)(dian)器(qi)(qi)(qi)(qi)也是(shi)(shi)(shi)歷史(shi)很長的(de)、性能指標非常(chang)好(hao)的(de)傳(chuan)統電(dian)(dian)(dian)路(lu)，輸(shu)(shu)出(chu)電(dian)(dian)(dian)壓精度很容易做(zuo)到(dao)(dao)1%，輸(shu)(shu)出(chu)電(dian)(dian)(dian)壓紋波做(zuo)到(dao)(dao)<5mV則輕而易舉；測量與(yu)控制(zhi)電(dian)(dian)(dian)路(lu)都是(shi)(shi)(shi)由傳(chuan)統的(de)比較(jiao)器(qi)(qi)(qi)(qi)、運算(suan)放大器(qi)(qi)(qi)(qi)之類的(de)組件構(gou)成，可靠性當然更(geng)無問題；執行器(qi)(qi)(qi)(qi)件是(shi)(shi)(shi)一只繼(ji)電(dian)(dian)(dian)器(qi)(qi)(qi)(qi)，一般觸點的(de)動作次(ci)數都在106次(ci)以上。

　　b.電(dian)(dian)(dian)(dian)路(lu)工作原理簡單、實用(yong)。充(chong)(chong)電(dian)(dian)(dian)(dian)器的(de)兩(liang)個主要功能就是(shi)限流(liu)(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)和穩壓(ya)浮充(chong)(chong)。該電(dian)(dian)(dian)(dian)路(lu)中(zhong)的(de)限流(liu)(liu)(liu)是(shi)靠一只(zhi)電(dian)(dian)(dian)(dian)容器來(lai)完成的(de)，既(ji)無(wu)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)傳感器又無(wu)反饋控(kong)制機構(gou)，僅(jin)僅(jin)靠電(dian)(dian)(dian)(dian)容本身的(de)電(dian)(dian)(dian)(dian)壓(ya)自調(diao)整(zheng)就實現了(le)限流(liu)(liu)(liu)功能；大電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)和高精度浮充(chong)(chong)溫壓(ya)分別(bie)進行(xing)，就大大簡化了(le)電(dian)(dian)(dian)(dian)路(lu)，指標也(ye)容易做得(de)好；用(yong)繼電(dian)(dian)(dian)(dian)器做主充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)路(lu)和輔(fu)助充(chong)(chong)電(dian)(dian)(dian)(dian)器（線性穩壓(ya)器）的(de)切(qie)換(huan)(huan)機構(gou)而不考慮(lv)0切(qie)換(huan)(huan)，這正是(shi)利用(yong)了(le)電(dian)(dian)(dian)(dian)路(lu)對該指標不加考慮(lv)的(de)特點。

　　c.整個電(dian)(dian)路的(de)(de)工(gong)作(zuo)狀態(tai)都是(shi)線(xian)(xian)性的(de)(de)，無產生高頻干擾的(de)(de)機構和(he)(he)過程。主回路的(de)(de)電(dian)(dian)容器和(he)(he)普通整流器都自然地工(gong)作(zuo)于50Hz，線(xian)(xian)性穩(wen)壓器從(cong)小信(xin)號到大信(xin)號都是(shi)典型的(de)(de)線(xian)(xian)性工(gong)作(zuo)狀態(tai)，測量(liang)與控制電(dian)(dian)路也僅(jin)僅(jin)是(shi)對直流電(dian)(dian)平的(de)(de)線(xian)(xian)性轉(zhuan)換。

　　因此(ci)，整個電(dian)路從原理(li)上(shang)就杜絕了高頻(pin)干(gan)擾的(de)(de)(de)發生。不過這種(zhong)電(dian)路比(bi)同容量的(de)(de)(de)PWM充(chong)電(dian)器體積(ji)要大一(yi)些。因此(ci)，在那些對干(gan)擾指標(biao)要求不太嚴格的(de)(de)(de)地方，PWM充(chong)電(dian)器還是得到了廣泛的(de)(de)(de)應用。

　　(3)雙電池組充電器：

　　①升壓（Boost）充電(dian)(dian)(dian)電(dian)(dian)(dian)路。單(dan)電(dian)(dian)(dian)子器件的(de)(de)發(fa)展促(cu)進了UPS技術(shu)的(de)(de)發(fa)展，近年來(lai)高頻機UPS的(de)(de)出現，使該類產(chan)品的(de)(de)逆變(bian)器輸出省去了笨(ben)重的(de)(de)隔離變(bian)壓器，同時將電(dian)(dian)(dian)池由(you)一(yi)組(zu)(zu)(zu)增(zeng)加(jia)到(dao)兩(liang)(liang)組(zu)(zu)(zu)，但容量不變(bian)，比如(ru)原來(lai)用一(yi)組(zu)(zu)(zu)電(dian)(dian)(dian)池時是100Ah，而現在變(bian)成了兩(liang)(liang)組(zu)(zu)(zu)50Ah。如(ru)圖5所(suo)示的(de)(de)GB1和GB2。兩(liang)(liang)組(zu)(zu)(zu)電(dian)(dian)(dian)池串聯連接，每組(zu)(zu)(zu)電(dian)(dian)(dian)池標稱(cheng)電(dian)(dian)(dian)壓一(yi)般為384V，兩(liang)(liang)組(zu)(zu)(zu)串聯總電(dian)(dian)(dian)壓為768V，若(ruo)按照2.25V/單(dan)元的(de)(de)標準充電(dian)(dian)(dian)，兩(liang)(liang)組(zu)(zu)(zu)電(dian)(dian)(dian)池的(de)(de)浮充電(dian)(dian)(dian)壓就需(xu)：