電(dian)(dian)(dian)(dian)池的(de)(de)(de)(de)(de)質量(liang)問題固然對UPS至關重(zhong)要，但充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器的(de)(de)(de)(de)(de)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)質量(liang)在(zai)(zai)很大程度(du)上影響著電(dian)(dian)(dian)(dian)池的(de)(de)(de)(de)(de)質量(liang)，其原因(yin)在(zai)(zai)前面已經(jing)提及。尤(you)其是(shi)(shi)電(dian)(dian)(dian)(dian)池充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓(ya)(ya)的(de)(de)(de)(de)(de)精(jing)度(du)一定(ding)要保證(zheng)，因(yin)為浮(fu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)壓(ya)(ya)的(de)(de)(de)(de)(de)過(guo)高或過(guo)低都(dou)會影響電(dian)(dian)(dian)(dian)池的(de)(de)(de)(de)(de)壽命(ming)，圖(tu)1表示的(de)(de)(de)(de)(de)是(shi)(shi)MSE電(dian)(dian)(dian)(dian)池的(de)(de)(de)(de)(de)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓(ya)(ya)與(yu)壽命(ming)的(de)(de)(de)(de)(de)關系，該實驗是(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(ci)曲(qu)線可(ke)以(yi)看出，在(zai)(zai)這(zhe)里的(de)(de)(de)(de)(de)浮(fu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)壓(ya)(ya)推薦值(zhi)是(shi)(shi)2.25V/cell，高于這(zhe)個(ge)值(zhi)或低于這(zhe)個(ge)值(zhi)都(dou)會縮(suo)短(duan)電(dian)(dian)(dian)(dian)池的(de)(de)(de)(de)(de)壽命(ming)。比如浮(fu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)壓(ya)(ya)是(shi)(shi)2.225V/cell時(shi)(shi)，壽命(ming)將縮(suo)短(duan)5%，而(er)浮(fu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)壓(ya)(ya)上升到2.4V/cell時(shi)(shi)，壽命(ming)就(jiu)縮(suo)短(duan)了(le)40%。由此(ci)可(ke)見，維持(chi)精(jing)確的(de)(de)(de)(de)(de)浮(fu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)壓(ya)(ya)值(zhi)是(shi)(shi)如何(he)重(zhong)要。但為了(le)使(shi)電(dian)(dian)(dian)(dian)池長期使(shi)用(yong)后還(huan)能保證(zheng)各電(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)壓(ya)(ya)的(de)(de)(de)(de)(de)平(ping)衡，采用(yong)的(de)(de)(de)(de)(de)措施是(shi)(shi)均(jun)衡充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)，而(er)均(jun)衡充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)壓(ya)(ya)也大都(dou)是(shi)(shi)2.4V/cell，這(zhe)就(jiu)和上面的(de)(de)(de)(de)(de)曲(qu)線發(fa)生了(le)矛盾，實際上事(shi)情就(jiu)是(shi)(shi)這(zhe)樣，有(you)得就(jiu)有(you)失，所以(yi)電(dian)(dian)(dian)(dian)池在(zai)(zai)均(jun)衡充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)時(shi)(shi)一定(ding)要控制好時(shi)(shi)間(jian)，以(yi)盡(jin)量(liang)延長電(dian)(dian)(dian)(dian)池的(de)(de)(de)(de)(de)服務壽命(ming)。

　　圖1 MSE電(dian)池的充電(dian)電(dian)壓(ya)與壽命的關系（40oC加速實驗）

1.恒壓充電

　　所謂恒(heng)壓充(chong)電就是用一穩壓源給電池充(chong)電，這(zhe)種方法(fa)簡單易行(xing)(xing)，也能夠保證電池的(de)(de)(de)精確浮充(chong)電壓。但若在電池深度放電后(hou)充(chong)電時(shi)，由于電池的(de)(de)(de)內阻(zu)相(xiang)對而言仍然很低(di)，就會有很大(da)的(de)(de)(de)充(chong)電電流使(shi)(shi)化學(xue)反應(ying)劇烈地進行(xing)(xing)，從(cong)而產(chan)生大(da)量的(de)(de)(de)氣體，由于還(huan)原(yuan)反應(ying)來不及(ji)進行(xing)(xing)，使(shi)(shi)殼(ke)(ke)內氣壓迅速增(zeng)加，沖開排氣閥(fa)將(jiang)氣體逸(yi)出，加速了(le)電解液的(de)(de)(de)干涸，縮短了(le)電池的(de)(de)(de)壽命(ming)；若排氣閥(fa)因故(gu)障而無法(fa)打(da)開，就會使(shi)(shi)電池的(de)(de)(de)外殼(ke)(ke)鼓脹或破裂。隨著電池電壓的(de)(de)(de)升高，充(chong)電電流逐漸減小(xiao)(xiao)，其減小(xiao)(xiao)的(de)(de)(de)規律(lv)是：

 　　                                             （1）

式中   ICH――電池的充電電流，A；

       E――充電器的(de)輸(shu)出電壓(ya)，V；

       UGB――電池電壓，V；

       RGB――電(dian)池的內(nei)阻，Ω。

　　上(shang)式中有(you)三個(ge)變(bian)量ICH、UGB、RGB，充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流ICH隨著充(chong)電(dian)(dian)(dian)(dian)過(guo)程(cheng)的(de)進行(xing)而(er)減小(xiao)，電(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)壓UGB隨著充(chong)電(dian)(dian)(dian)(dian)過(guo)程(cheng)的(de)進行(xing)而(er)升高，而(er)電(dian)(dian)(dian)(dian)池內阻RGB隨著充(chong)電(dian)(dian)(dian)(dian)過(guo)程(cheng)的(de)進行(xing)而(er)減小(xiao)。這就(jiu)決定(ding)了充(chong)電(dian)(dian)(dian)(dian)過(guo)程(cheng)的(de)非線性(xing)。尤(you)其是在(zai)接近浮充(chong)電(dian)(dian)(dian)(dian)壓值時，使充(chong)電(dian)(dian)(dian)(dian)變(bian)的(de)非常緩慢，從理(li)論上(shang)講，充(chong)電(dian)(dian)(dian)(dian)到(dao)額定(ding)浮充(chong)值的(de)時間是無(wu)窮大。

　　這(zhe)種充電方(fang)式(shi)在(zai)早期的小容量UPS中曾一度使用過(guo)，因出現(xian)了好多故障(zhang)，目前一般不(bu)用了。{{分(fen)頁}}

2.恒流充電

　　恒流充(chong)(chong)電(dian)(dian)(dian)(dian)的(de)(de)好處(chu)在于(yu)：一(yi)方面可以限制充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流，避免(mian)了(le)(le)由于(yu)上(shang)述的(de)(de)劇烈反應而導(dao)致(zhi)(zhi)的(de)(de)副作用(yong)(yong)；另一(yi)方面，可使充(chong)(chong)電(dian)(dian)(dian)(dian)直線進(jin)行(xing)，加快(kuai)(kuai)了(le)(le)充(chong)(chong)電(dian)(dian)(dian)(dian)的(de)(de)速度，也可避免(mian)接近浮(fu)充(chong)(chong)值(zhi)(zhi)時的(de)(de)過于(yu)緩慢的(de)(de)過程。這種方法也有(you)不足之處(chu)，因為隨著充(chong)(chong)電(dian)(dian)(dian)(dian)過程的(de)(de)進(jin)行(xing)，未經反應的(de)(de)物(wu)質(zhi)會越來越少，如(ru)果(guo)仍用(yong)(yong)充(chong)(chong)電(dian)(dian)(dian)(dian)初期的(de)(de)電(dian)(dian)(dian)(dian)流注入，由于(yu)反應物(wu)質(zhi)的(de)(de)缺乏就(jiu)會用(yong)(yong)水的(de)(de)電(dian)(dian)(dian)(dian)解來填(tian)補，這又(you)會導(dao)致(zhi)(zhi)水的(de)(de)電(dian)(dian)(dian)(dian)離物(wu)氫和氧的(de)(de)快(kuai)(kuai)速蒸發，從而也縮短(duan)了(le)(le)電(dian)(dian)(dian)(dian)池的(de)(de)服務壽命(ming)(ming)。因此(ci)也有(you)的(de)(de)提出在電(dian)(dian)(dian)(dian)池浮(fu)充(chong)(chong)電(dian)(dian)(dian)(dian)到“一(yi)定(ding)值(zhi)(zhi)”時將充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流減半。就(jiu)是(shi)這個“一(yi)定(ding)值(zhi)(zhi)”也很難掌(zhang)握(wo)，尤(you)其是(shi)接近額(e)定(ding)浮(fu)充(chong)(chong)電(dian)(dian)(dian)(dian)壓值(zhi)(zhi)時，如(ru)果(guo)仍用(yong)(yong)這個即使是(shi)減了(le)(le)半的(de)(de)電(dian)(dian)(dian)(dian)流強行(xing)灌入，也會加快(kuai)(kuai)電(dian)(dian)(dian)(dian)解水的(de)(de)進(jin)程，縮短(duan)電(dian)(dian)(dian)(dian)池的(de)(de)壽命(ming)(ming)。因此(ci)這個界限也難于(yu)劃分(fen)和掌(zhang)握(wo)。此(ci)種方法有(you)的(de)(de)在均衡(heng)充(chong)(chong)電(dian)(dian)(dian)(dian)中使用(yong)(yong)。

3.恒流恒壓充電

　　鑒于(yu)(yu)(yu)上述兩種充(chong)電(dian)(dian)方(fang)式(shi)的(de)(de)優(you)點和不(bu)足，于(yu)(yu)(yu)是就(jiu)推(tui)出了將(jiang)二(er)者優(you)點集合與(yu)一(yi)體的(de)(de)所(suo)謂(wei)恒(heng)流(liu)(liu)(liu)恒(heng)壓充(chong)電(dian)(dian)方(fang)式(shi)，實際(ji)上是限(xian)流(liu)(liu)(liu)恒(heng)壓充(chong)電(dian)(dian)方(fang)式(shi)。在充(chong)電(dian)(dian)初(chu)期由于(yu)(yu)(yu)電(dian)(dian)流(liu)(liu)(liu)有(you)可能(neng)非常大，所(suo)以這(zhe)時的(de)(de)充(chong)電(dian)(dian)電(dian)(dian)路(lu)將(jiang)該電(dian)(dian)流(liu)(liu)(liu)限(xian)制在一(yi)個規定(ding)值，使之(zhi)能(neng)最大限(xian)度地保(bao)證(zheng)既(ji)能(neng)快(kuai)速充(chong)電(dian)(dian)，又(you)能(neng)保(bao)證(zheng)充(chong)電(dian)(dian)過(guo)程的(de)(de)安全。這(zhe)一(yi)段的(de)(de)充(chong)電(dian)(dian)幾乎是線性的(de)(de)，隨著充(chong)電(dian)(dian)過(guo)程的(de)(de)進行，大約充(chong)電(dian)(dian)至80%～90%電(dian)(dian)池容量(liang)時，充(chong)電(dian)(dian)電(dian)(dian)流(liu)(liu)(liu)開始(shi)小于(yu)(yu)(yu)限(xian)流(liu)(liu)(liu)值，其電(dian)(dian)流(liu)(liu)(liu)的(de)(de)變(bian)化(hua)開始(shi)遵從式(shi)(1)。目前(qian)UPS中的(de)(de)充(chong)電(dian)(dian)大都采(cai)用這(zhe)種方(fang)式(shi)。

4.充電電路

　　(1)概(gai)述  UPS中(zhong)(zhong)(zhong)電(dian)池的(de)充(chong)(chong)(chong)(chong)電(dian)電(dian)路不外乎(hu)兩種：降(jiang)壓(ya)(ya)(ya)(ya)(ya)(ya)充(chong)(chong)(chong)(chong)電(dian)電(dian)路和升壓(ya)(ya)(ya)(ya)(ya)(ya)充(chong)(chong)(chong)(chong)電(dian)電(dian)路。在(zai)一(yi)些小(xiao)容量(liang)UPS中(zhong)(zhong)(zhong)，由(you)于電(dian)池組電(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)比較低，故(gu)多(duo)用降(jiang)壓(ya)(ya)(ya)(ya)(ya)(ya)電(dian)路，比如Smart、Matrix和Symmetra等系列(lie)UPS中(zhong)(zhong)(zhong)，電(dian)池組額定電(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)最(zui)高也就是(shi)(shi)120V，浮充(chong)(chong)(chong)(chong)電(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)也小(xiao)于140V，由(you)單相220V交流電(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)足(zu)可以得到此值；為了(le)提高充(chong)(chong)(chong)(chong)電(dian)器的(de)效率(lv)和降(jiang)低功(gong)耗，充(chong)(chong)(chong)(chong)電(dian)器多(duo)采用稱為Buck電(dian)路的(de)高頻PWM方案，這在(zai)前面已有介紹(shao)。在(zai)中(zhong)(zhong)(zhong)大容量(liang)的(de)UPS系統中(zhong)(zhong)(zhong)，輸(shu)入多(duo)是(shi)(shi)三(san)相電(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)，又由(you)于輸(shu)入整(zheng)流器采用了(le)相控的(de)晶閘(zha)管方案，本(ben)身(shen)的(de)輸(shu)出電(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)穩定度已達到了(le)蓄(xu)電(dian)池的(de)要(yao)求，故(gu)電(dian)池的(de)充(chong)(chong)(chong)(chong)電(dian)功(gong)能統一(yi)由(you)整(zheng)流器負(fu)擔(dan)，這也是(shi)(shi)一(yi)個降(jiang)壓(ya)(ya)(ya)(ya)(ya)(ya)充(chong)(chong)(chong)(chong)電(dian)電(dian)路。

　　只(zhi)有一部分小容量UPS采用了(le)高壓電(dian)(dian)池組(zu)，比如單相(xiang)220V輸入(ru)的(de)(de)(de)(de)Imel 7.5kVA UPS就(jiu)(jiu)(jiu)采用了(le)384V的(de)(de)(de)(de)電(dian)(dian)池電(dian)(dian)壓，遠(yuan)遠(yuan)超(chao)過(guo)了(le)220V交流電(dian)(dian)壓幅值310V，因此(ci)不提高電(dian)(dian)壓就(jiu)(jiu)(jiu)無法(fa)滿足電(dian)(dian)池組(zu)的(de)(de)(de)(de)充電(dian)(dian)要(yao)求。所以(yi)機器中就(jiu)(jiu)(jiu)采用了(le)稱為(wei)Boost的(de)(de)(de)(de)升壓PWM電(dian)(dian)路。

　　一般UPS電(dian)(dian)源(yuan)的(de)(de)(de)(de)后(hou)備(bei)時間大都在10min左右(you)，充(chong)(chong)電(dian)(dian)器的(de)(de)(de)(de)設計也與此(ci)對應。如遇有長(chang)延時的(de)(de)(de)(de)要求，雖然(ran)(ran)增加(jia)了電(dian)(dian)池(chi)可以滿足(zu)其放電(dian)(dian)的(de)(de)(de)(de)能(neng)力，但充(chong)(chong)電(dian)(dian)的(de)(de)(de)(de)速度就(jiu)遠達(da)不到目的(de)(de)(de)(de)了。比如一般UPS內含10min電(dian)(dian)池(chi)時，放電(dian)(dian)后(hou)重新充(chong)(chong)電(dian)(dian)的(de)(de)(de)(de)時間為(wei)10～12h。當有的(de)(de)(de)(de)用(yong)戶提出(chu)了8h要求時，電(dian)(dian)池(chi)容量增加(jia)到原來(lai)的(de)(de)(de)(de)48倍！若充(chong)(chong)足(zu)如此(ci)大的(de)(de)(de)(de)電(dian)(dian)池(chi)顯然(ran)(ran)不能(neng)靠UPS的(de)(de)(de)(de)內部(bu)充(chong)(chong)電(dian)(dian)器了。于是就(jiu)提出(chu)了外加(jia)充(chong)(chong)電(dian)(dian)器的(de)(de)(de)(de)要求。

　　(2)UPS外(wai)(wai)(wai)(wai)加(jia)(jia)(jia)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)的(de)(de)(de)(de)(de)配(pei)置原(yuan)則  UPS外(wai)(wai)(wai)(wai)加(jia)(jia)(jia)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)的(de)(de)(de)(de)(de)配(pei)置原(yuan)則首先是(shi)要(yao)和UPS隔(ge)(ge)(ge)離(li)，其(qi)次才(cai)是(shi)電(dian)(dian)(dian)(dian)(dian)磁兼容指標要(yao)和UPS相(xiang)適應。以(yi)往市場上的(de)(de)(de)(de)(de)商品充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)雖然(ran)也(ye)(ye)考(kao)慮了(le)(le)(le)隔(ge)(ge)(ge)離(li)問題(ti)，并且(qie)也(ye)(ye)采取了(le)(le)(le)措(cuo)施，但由(you)(you)于措(cuo)施不利，也(ye)(ye)不乏導(dao)致UPS故(gu)障的(de)(de)(de)(de)(de)例子(zi)(zi)。圖2就是(shi)一(yi)般外(wai)(wai)(wai)(wai)加(jia)(jia)(jia)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)隔(ge)(ge)(ge)離(li)措(cuo)施圖，實(shi)際上所謂(wei)的(de)(de)(de)(de)(de)隔(ge)(ge)(ge)離(li)措(cuo)施就是(shi)一(yi)只(zhi)二極管。GB1是(shi)UPS內部(bu)電(dian)(dian)(dian)(dian)(dian)池組(zu)(zu)，GB2是(shi)外(wai)(wai)(wai)(wai)加(jia)(jia)(jia)長延(yan)時(shi)電(dian)(dian)(dian)(dian)(dian)池組(zu)(zu)，而往往由(you)(you)于外(wai)(wai)(wai)(wai)加(jia)(jia)(jia)電(dian)(dian)(dian)(dian)(dian)池組(zu)(zu)的(de)(de)(de)(de)(de)容量遠大于內部(bu)電(dian)(dian)(dian)(dian)(dian)池組(zu)(zu)，一(yi)般將GB1省(sheng)掉了(le)(le)(le)，無論是(shi)省(sheng)掉還(huan)是(shi)不省(sheng)掉，都有(you)一(yi)個(ge)不變的(de)(de)(de)(de)(de)事(shi)實(shi)，即UPS內部(bu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)和外(wai)(wai)(wai)(wai)加(jia)(jia)(jia)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)的(de)(de)(de)(de)(de)直接并聯。為(wei)了(le)(le)(le)隔(ge)(ge)(ge)離(li)相(xiang)互間(jian)的(de)(de)(de)(de)(de)影響，多(duo)數外(wai)(wai)(wai)(wai)加(jia)(jia)(jia)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)多(duo)在(zai)其(qi)輸(shu)出(chu)正端串聯了(le)(le)(le)一(yi)只(zhi)正向二極管D。這樣做(zuo)的(de)(de)(de)(de)(de)結果是(shi)隔(ge)(ge)(ge)離(li)了(le)(le)(le)UPS對充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)的(de)(de)(de)(de)(de)影響，保證了(le)(le)(le)它(ta)不受其(qi)干擾(rao)，但沒有(you)消除充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)對UPS的(de)(de)(de)(de)(de)干擾(rao)。而且(qie)最(zui)關鍵(jian)的(de)(de)(de)(de)(de)就是(shi)怕外(wai)(wai)(wai)(wai)加(jia)(jia)(jia)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)對UPS的(de)(de)(de)(de)(de)干擾(rao)。當(dang)外(wai)(wai)(wai)(wai)加(jia)(jia)(jia)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)壓因失控而突然(ran)增高時(shi)，它(ta)就會(hui)通過二極管去干擾(rao)UPS，如果該外(wai)(wai)(wai)(wai)加(jia)(jia)(jia)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)的(de)(de)(de)(de)(de)輸(shu)出(chu)電(dian)(dian)(dian)(dian)(dian)壓是(shi)由(you)(you)市電(dian)(dian)(dian)(dian)(dian)直接整流后通過開關管斬波(PWM)而來，這就將市電(dian)(dian)(dian)(dian)(dian)直接接入UPS直流電(dian)(dian)(dian)(dian)(dian)路，就會(hui)導(dao)致故(gu)障。當(dang)然(ran)，此類故(gu)障不會(hui)多(duo)見，但導(dao)致UPS冒(mao)煙的(de)(de)(de)(de)(de)例子(zi)(zi)已經有(you)過。這種明顯存(cun)在(zai)隱患的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)路一(yi)定要(yao)謹用。

　　圖2 一(yi)般外加充(chong)電器(qi)隔離措(cuo)施圖

　　為了(le)完(wan)(wan)全(quan)隔離相互間的(de)干擾，圖3的(de)外(wai)加充電器完(wan)(wan)全(quan)隔離方案是可取的(de)，并在長期(qi)的(de)實(shi)踐運行中得到(dao)了(le)證明，既安全(quan)又可靠。{{分(fen)頁}}

　　圖(tu)3 外(wai)加充(chong)電(dian)器完全隔離方案原理圖(tu)

　　①外加充電器完全隔(ge)離(li)方案設計思想：

　　a.充分保證UPS電路的(de)(de)(de)完整性，即該方案不動UPS的(de)(de)(de)一(yi)點一(yi)線(xian)，不從UPS機(ji)內引出(chu)(chu)任何附加的(de)(de)(de)信號線(xian)。按(an)照UPS正常的(de)(de)(de)要求，只(zhi)從UPS的(de)(de)(de)輸出(chu)(chu)接(jie)線(xian)端子做正常連接(jie)。

　　b.在外加(jia)充電(dian)(dian)器(qi)與UPS電(dian)(dian)池之間加(jia)接(jie)(jie)一個(ge)簡單的(de)三端雙向互投機構，如圖(tu)3所示，用一個(ge)中間繼(ji)電(dian)(dian)器(qi)J（或(huo)接(jie)(jie)觸器(qi)甚至(zhi)雙投手(shou)動開關），將該機構的(de)中間臂(bei)3接(jie)(jie)外加(jia)電(dian)(dian)池組(zu)GB2的(de)正極，繼(ji)電(dian)(dian)器(qi)線包J跨接(jie)(jie)在UPS市電(dian)(dian)輸入線上。

　　c.當市電(dian)(dian)正常(chang)供電(dian)(dian)時(shi)，由(you)于繼電(dian)(dian)器(qi)(qi)線(xian)包J被激勵(li)而(er)將觸(chu)點臂(bei)3由(you)常(chang)閉觸(chu)點1打向2，此時(shi)正好是(shi)外(wai)加(jia)充電(dian)(dian)器(qi)(qi)正常(chang)輸出充電(dian)(dian)時(shi)期，GB2被正常(chang)充電(dian)(dian)。可(ke)以看出，此時(shi)UPS和外(wai)加(jia)充電(dian)(dian)器(qi)(qi)是(shi)完全隔離(li)的，并且UPS的充電(dian)(dian)器(qi)(qi)僅僅給(gei)自己的電(dian)(dian)池GB1充電(dian)(dian)，保證了(le)其原有的一(yi)切(qie)充電(dian)(dian)功能。

　　d.當市電(dian)斷電(dian)時(shi)，繼電(dian)器線(xian)包(bao)J被釋放(fang)，中間臂3由2回(hui)到1，將外加電(dian)池組(zu)GB2并聯(lian)在GB1上，形(xing)成了純電(dian)池組(zu)的(de)并聯(lian)，也(ye)就達到了大(da)容量電(dian)池長延時(shi)放(fang)電(dian)的(de)目的(de)。

　　e.市電(dian)(dian)(dian)(dian)恢復時，繼電(dian)(dian)(dian)(dian)器(qi)(qi)又回到“3-2”狀(zhuang)態。這(zhe)里可能(neng)有(you)這(zhe)樣一個問題：市電(dian)(dian)(dian)(dian)恢復時，由于(yu)繼電(dian)(dian)(dian)(dian)器(qi)(qi)動作存(cun)在惰性，有(you)可能(neng)外加電(dian)(dian)(dian)(dian)池組GB2不能(neng)及時斷(duan)開，將會造成UPS內(nei)部充電(dian)(dian)(dian)(dian)器(qi)(qi)同時為(wei)兩組電(dian)(dian)(dian)(dian)池充電(dian)(dian)(dian)(dian)的局(ju)面，會不會因充電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流太大而(er)導致(zhi)故障呢？回答是(shi)否定的。因為(wei)所有(you)在線式(shi)UPS的充電(dian)(dian)(dian)(dian)器(qi)(qi)都是(shi)限流溫(wen)壓式(shi)的，所以不會過流。

　　上面(mian)只是給出了一(yi)個原(yuan)理方案，實際結構還要復雜一(yi)些。不過，用這(zhe)個原(yuan)理進行隔離已經足夠了。

　　關(guan)于外加充(chong)(chong)電(dian)器的(de)(de)電(dian)磁(ci)兼容問題(ti)也不(bu)可忽視，由(you)于現代UPS的(de)(de)用戶大(da)都(dou)集(ji)通信和大(da)量(liang)的(de)(de)數據傳輸為一(yi)(yi)體，尤其牽涉到無線通信，就更要求供電(dian)系統(tong)不(bu)能對用電(dian)系統(tong)有(you)(you)任何干擾(rao)。因此，一(yi)(yi)般UPS系統(tong)都(dou)要通過一(yi)(yi)定的(de)(de)電(dian)磁(ci)兼容標準，如(ru)EN50091-2等。然而一(yi)(yi)般市(shi)面上的(de)(de)外加充(chong)(chong)電(dian)器很少注意到這些問題(ti)，恰(qia)恰(qia)PWM開(kai)關(guan)電(dian)源就是無線通信的(de)(de)敏感干擾(rao)源，因此不(bu)得(de)不(bu)向其提出相(xiang)應的(de)(de)要求。有(you)(you)時為了安全起見(jian)，采(cai)用原(yuan)理(li)上的(de)(de)無干擾(rao)電(dian)路是必(bi)要的(de)(de)。圖(tu)4表示的(de)(de)就是這樣一(yi)(yi)種(zhong)無干擾(rao)充(chong)(chong)電(dian)器電(dian)路原(yuan)理(li)圖(tu)，這是一(yi)(yi)個典型的(de)(de)具有(you)(you)限流穩壓功能的(de)(de)充(chong)(chong)電(dian)器。

　　圖4 無干擾(rao)充電器電路原理圖{{分頁(ye)}}

　　②無干(gan)擾充電(dian)器(qi)電(dian)路特點：

　　a.電(dian)(dian)(dian)路(lu)結構簡單(dan)、成(cheng)熟、可(ke)靠。主回路(lu)只有電(dian)(dian)(dian)容(rong)器(qi)(qi)(qi)和普(pu)通(tong)整(zheng)流器(qi)(qi)(qi)，這種傳(chuan)統(tong)器(qi)(qi)(qi)件(jian)的(de)(de)制(zhi)造歷史很(hen)長，已(yi)達(da)到很(hen)高的(de)(de)可(ke)靠性(xing)指標；輔助充(chong)電(dian)(dian)(dian)器(qi)(qi)(qi)也是(shi)歷史很(hen)長的(de)(de)、性(xing)能指標非常好(hao)的(de)(de)傳(chuan)統(tong)電(dian)(dian)(dian)路(lu)，輸出(chu)電(dian)(dian)(dian)壓(ya)精度很(hen)容(rong)易(yi)做到1%，輸出(chu)電(dian)(dian)(dian)壓(ya)紋波做到<5mV則輕而易(yi)舉(ju)；測(ce)量與控制(zhi)電(dian)(dian)(dian)路(lu)都是(shi)由(you)傳(chuan)統(tong)的(de)(de)比較(jiao)器(qi)(qi)(qi)、運算放(fang)大(da)器(qi)(qi)(qi)之類的(de)(de)組件(jian)構成(cheng)，可(ke)靠性(xing)當然更無問題；執行器(qi)(qi)(qi)件(jian)是(shi)一只繼電(dian)(dian)(dian)器(qi)(qi)(qi)，一般觸點(dian)的(de)(de)動作次數都在106次以上。

　　b.電(dian)(dian)(dian)路(lu)(lu)工(gong)作原理簡單、實用(yong)。充(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)的(de)(de)兩個主(zhu)要功能(neng)就(jiu)是(shi)限流(liu)(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)和穩(wen)壓浮充(chong)(chong)(chong)。該(gai)電(dian)(dian)(dian)路(lu)(lu)中的(de)(de)限流(liu)(liu)是(shi)靠(kao)一只電(dian)(dian)(dian)容(rong)器(qi)來完成的(de)(de)，既無電(dian)(dian)(dian)流(liu)(liu)傳感器(qi)又無反饋控制機構(gou)，僅僅靠(kao)電(dian)(dian)(dian)容(rong)本身的(de)(de)電(dian)(dian)(dian)壓自調整(zheng)就(jiu)實現了(le)限流(liu)(liu)功能(neng)；大(da)電(dian)(dian)(dian)流(liu)(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)和高(gao)精度浮充(chong)(chong)(chong)溫壓分別進行，就(jiu)大(da)大(da)簡化了(le)電(dian)(dian)(dian)路(lu)(lu)，指標也容(rong)易做得好；用(yong)繼電(dian)(dian)(dian)器(qi)做主(zhu)充(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)路(lu)(lu)和輔助(zhu)充(chong)(chong)(chong)電(dian)(dian)(dian)器(qi)（線性穩(wen)壓器(qi)）的(de)(de)切換機構(gou)而不(bu)考慮0切換，這正是(shi)利用(yong)了(le)電(dian)(dian)(dian)路(lu)(lu)對該(gai)指標不(bu)加考慮的(de)(de)特(te)點。

　　c.整(zheng)個電路(lu)的(de)工(gong)作狀(zhuang)態(tai)都(dou)是線性(xing)(xing)的(de)，無產生(sheng)高頻干擾的(de)機構和過程(cheng)。主回路(lu)的(de)電容器和普(pu)通整(zheng)流(liu)器都(dou)自然(ran)地(di)工(gong)作于50Hz，線性(xing)(xing)穩壓器從小信號到大信號都(dou)是典型(xing)的(de)線性(xing)(xing)工(gong)作狀(zhuang)態(tai)，測(ce)量(liang)與控制電路(lu)也僅(jin)僅(jin)是對直流(liu)電平的(de)線性(xing)(xing)轉換。

　　因此，整(zheng)個電(dian)(dian)(dian)路(lu)從原理上就杜絕了高頻(pin)干(gan)擾的發(fa)生。不過這(zhe)種電(dian)(dian)(dian)路(lu)比同容(rong)量的PWM充(chong)電(dian)(dian)(dian)器體積要(yao)大一些(xie)。因此，在(zai)那些(xie)對干(gan)擾指標要(yao)求不太嚴格的地方，PWM充(chong)電(dian)(dian)(dian)器還是(shi)得到了廣(guang)泛的應用。

　　(3)雙(shuang)電池組充電器(qi)：

　　①升壓（Boost）充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)路。單電(dian)(dian)(dian)(dian)(dian)子器件的(de)發展促(cu)進了(le)UPS技術(shu)的(de)發展，近(jin)年來高頻(pin)機UPS的(de)出現，使(shi)該類產品的(de)逆變(bian)(bian)器輸(shu)出省去了(le)笨重的(de)隔離變(bian)(bian)壓器，同時將(jiang)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)由一組(zu)增加(jia)到兩(liang)組(zu)，但容量(liang)不變(bian)(bian)，比如原來用一組(zu)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)時是100Ah，而現在變(bian)(bian)成了(le)兩(liang)組(zu)50Ah。如圖5所示(shi)的(de)GB1和GB2。兩(liang)組(zu)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)串聯連(lian)接(jie)，每(mei)組(zu)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)標稱(cheng)電(dian)(dian)(dian)(dian)(dian)壓一般為384V，兩(liang)組(zu)串聯總電(dian)(dian)(dian)(dian)(dian)壓為768V，若按照(zhao)2.25V/單元(yuan)的(de)標準(zhun)充電(dian)(dian)(dian)(dian)(dian)，兩(liang)組(zu)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)浮充電(dian)(dian)(dian)(dian)(dian)壓就需：