鉛酸蓄電池充電機充電原理示意圖
鉛酸蓄(xu)電(dian)池(chi)由于其制造成本低，容量大(da)(da)，價格(ge)低廉(lian)而得(de)到了廣泛的使用。但是，若(ruo)使用不當(dang)，其壽(shou)命(ming)將大(da)(da)大(da)(da)縮短。影響(xiang)鉛酸蓄(xu)電(dian)池(chi)壽(shou)命(ming)的因素很多(duo)，而采用正確的充電(dian)方式，能(neng)有效延長(chang)蓄(xu)電(dian)池(chi)的使用壽(shou)命(ming)。
研究發現：電池充電過程對電池壽命影響最大，放電過程的影響較少。也就是說，絕大多數的蓄電池不是用壞的，而是“充壞”的。由此可見，一個好的充電器對蓄電池的使用(yong)壽命具(ju)有舉足(zu)輕重的作(zuo)用(yong)。
1 蓄電池充(chong)電理論(lun)基礎
上(shang)世紀60年代中(zhong)期，美國科學家馬斯對開口蓄電(dian)池的充(chong)電(dian)過程作了(le)大量(liang)的試驗研究，并(bing)提(ti)出(chu)了(le)以最低出(chu)氣(qi)率為前提(ti)的，蓄電(dian)池可接(jie)受的充(chong)電(dian)曲(qu)(qu)線，如圖1所(suo)示。實(shi)驗表明，如果充(chong)電(dian)電(dian)流按(an)這條曲(qu)(qu)線變化，就可以大大縮短充(chong)電(dian)時(shi)間，并(bing)且(qie)對電(dian)池的容量(liang)和壽命也沒有影響。原則上(shang)把(ba)這條曲(qu)(qu)線稱為最佳充(chong)電(dian)曲(qu)(qu)線，從而(er)奠定了(le)快速充(chong)電(dian)方(fang)法(fa)的研究方(fang)向[1，2]。
圖(tu)1最佳充(chong)電曲線(xian)
由圖(tu)1可以看(kan)出(chu)：初始充(chong)電(dian)電(dian)流很大，但是(shi)衰減很快。主要原因(yin)是(shi)充(chong)電(dian)過程中產(chan)(chan)生了(le)極(ji)化現(xian)象。在(zai)密封式(shi)蓄(xu)電(dian)池(chi)充(chong)電(dian)過程中，內(nei)部產(chan)(chan)生氧氣(qi)(qi)和(he)氫氣(qi)(qi)，當氧氣(qi)(qi)不能(neng)被及時(shi)吸收時(shi)，便(bian)堆積(ji)在(zai)正極(ji)板（正極(ji)板產(chan)(chan)生氧氣(qi)(qi)），使電(dian)池(chi)內(nei)部壓力加大，電(dian)池(chi)溫度上升，同時(shi)縮小了(le)正極(ji)板的(de)面積(ji)，表現(xian)為內(nei)阻上升，出(chu)現(xian)所謂的(de)極(ji)化現(xian)象。
蓄電池(chi)是可逆的(de)。其(qi)放電及充電的(de)化學反應式(shi)如下：
PbO2＋Pb＋2H2SO42PbSO4＋2H2O （1）
很顯然，充(chong)電(dian)(dian)(dian)過(guo)(guo)程和放電(dian)(dian)(dian)過(guo)(guo)程互(hu)為逆反(fan)應。可(ke)逆過(guo)(guo)程就是熱(re)力學(xue)(xue)的(de)(de)平衡過(guo)(guo)程，為保障(zhang)電(dian)(dian)(dian)池能(neng)夠始終維(wei)持在平衡狀態之下充(chong)電(dian)(dian)(dian)，必須盡量使通過(guo)(guo)電(dian)(dian)(dian)池的(de)(de)電(dian)(dian)(dian)流小一些。理想條(tiao)件是外加電(dian)(dian)(dian)壓等于電(dian)(dian)(dian)池本身的(de)(de)電(dian)(dian)(dian)動勢。但是，實(shi)踐表明，蓄電(dian)(dian)(dian)池充(chong)電(dian)(dian)(dian)時，外加電(dian)(dian)(dian)壓必須增大到一定數值(zhi)(zhi)才(cai)行(xing),而(er)這(zhe)(zhe)個(ge)數值(zhi)(zhi)又因為電(dian)(dian)(dian)極材(cai)料(liao)，溶液(ye)濃度等各(ge)種(zhong)(zhong)因素的(de)(de)差別而(er)在不同(tong)程度上超(chao)過(guo)(guo)了蓄電(dian)(dian)(dian)池的(de)(de)平衡電(dian)(dian)(dian)動勢值(zhi)(zhi)。在化(hua)學(xue)(xue)反(fan)應中，這(zhe)(zhe)種(zhong)(zhong)電(dian)(dian)(dian)動勢超(chao)過(guo)(guo)熱(re)力學(xue)(xue)平衡值(zhi)(zhi)的(de)(de)現(xian)象，就是極化(hua)現(xian)象。
一般來說，產生(sheng)極化現象有3個方(fang)面的(de)原因。
1）歐姆(mu)極(ji)(ji)(ji)化 充電(dian)過程中，正(zheng)負離子向兩極(ji)(ji)(ji)遷移。在(zai)離子遷移過程中不可避(bi)免(mian)地受到一定(ding)的(de)(de)阻(zu)力，稱為(wei)歐姆(mu)內阻(zu)。為(wei)了克(ke)服(fu)這個(ge)內阻(zu)，外加電(dian)壓(ya)就必須額外施加一定(ding)的(de)(de)電(dian)壓(ya)，以克(ke)服(fu)阻(zu)力推動離子遷移。該電(dian)壓(ya)以熱的(de)(de)方(fang)式(shi)轉化給(gei)環境，出現所謂的(de)(de)歐姆(mu)極(ji)(ji)(ji)化。隨(sui)著充電(dian)電(dian)流(liu)急劇(ju)加大(da)，歐姆(mu)極(ji)(ji)(ji)化將造(zao)成(cheng)蓄電(dian)池在(zai)充電(dian)過程中的(de)(de)高溫。
2）濃(nong)度(du)(du)極(ji)化(hua)(hua) 電流流過蓄電池時，為維持正(zheng)常的(de)反應(ying)(ying)，最理想的(de)情況是電極(ji)表(biao)面(mian)的(de)反應(ying)(ying)物(wu)能及時得到補(bu)充，生(sheng)成物(wu)能及時離去(qu)。實際(ji)上，生(sheng)成物(wu)和反應(ying)(ying)物(wu)的(de)擴散速度(du)(du)遠(yuan)遠(yuan)比不上化(hua)(hua)學(xue)反應(ying)(ying)速度(du)(du)，從而造成極(ji)板(ban)附近(jin)電解質(zhi)溶液(ye)濃(nong)度(du)(du)發生(sheng)變化(hua)(hua)。也就是說，從電極(ji)表(biao)面(mian)到中部溶液(ye)，電解液(ye)濃(nong)度(du)(du)分布不均勻。這種現象稱(cheng)為濃(nong)度(du)(du)極(ji)化(hua)(hua)。
3）電(dian)(dian)(dian)(dian)(dian)(dian)(dian)化(hua)(hua)學(xue)極(ji)(ji)(ji)(ji)(ji)(ji)化(hua)(hua) 這種極(ji)(ji)(ji)(ji)(ji)(ji)化(hua)(hua)是由(you)于電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)上進(jin)行(xing)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)化(hua)(hua)學(xue)反應的(de)(de)(de)速度，落后于電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)上電(dian)(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)運動的(de)(de)(de)速度造成的(de)(de)(de)。例(li)如：電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)負(fu)極(ji)(ji)(ji)(ji)(ji)(ji)放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)前，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)表(biao)面(mian)(mian)帶(dai)(dai)有(you)負(fu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)荷(he)，其附近溶(rong)液帶(dai)(dai)有(you)正電(dian)(dian)(dian)(dian)(dian)(dian)(dian)荷(he)，兩者處于平衡(heng)狀態(tai)。放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)時，立即有(you)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)釋放(fang)給(gei)外(wai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)表(biao)面(mian)(mian)負(fu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)荷(he)減少(shao)(shao)(shao)，而(er)金(jin)(jin)屬溶(rong)解的(de)(de)(de)氧(yang)化(hua)(hua)反應進(jin)行(xing)緩慢Me－e→Me＋，不能及時補充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)表(biao)面(mian)(mian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)的(de)(de)(de)減少(shao)(shao)(shao)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)表(biao)面(mian)(mian)帶(dai)(dai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)狀態(tai)發(fa)生變化(hua)(hua)。這種表(biao)面(mian)(mian)負(fu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)荷(he)減少(shao)(shao)(shao)的(de)(de)(de)狀態(tai)促(cu)進(jin)金(jin)(jin)屬中電(dian)(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)離開(kai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)，金(jin)(jin)屬離子(zi)(zi)Me＋轉入溶(rong)液，加速Me－e→Me＋反應進(jin)行(xing)。總(zong)有(you)一個時刻，達到新的(de)(de)(de)動態(tai)平衡(heng)。但與放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)前相比(bi)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)表(biao)面(mian)(mian)所(suo)(suo)帶(dai)(dai)負(fu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)荷(he)數目減少(shao)(shao)(shao)了，與此對應的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)勢(shi)(shi)變正。也(ye)就是電(dian)(dian)(dian)(dian)(dian)(dian)(dian)化(hua)(hua)學(xue)極(ji)(ji)(ji)(ji)(ji)(ji)化(hua)(hua)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)變高，從而(er)嚴重阻礙了正常的(de)(de)(de)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流。同理，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)正極(ji)(ji)(ji)(ji)(ji)(ji)放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)時，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)表(biao)面(mian)(mian)所(suo)(suo)帶(dai)(dai)正電(dian)(dian)(dian)(dian)(dian)(dian)(dian)荷(he)數目減少(shao)(shao)(shao)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)勢(shi)(shi)變負(fu)。
這3種極化現象都是(shi)隨著充電電流的增大而(er)嚴重。
2 充電方法(fa)的研(yan)究
2.1 常規充電法
常規(gui)(gui)充(chong)電(dian)(dian)(dian)制度是(shi)依據(ju)1940年前國際公(gong)認的(de)(de)(de)經驗法則設(she)計的(de)(de)(de)。其中(zhong)最著名的(de)(de)(de)就是(shi)“安培小時規(gui)(gui)則”：充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流安培數(shu)，不應超過蓄電(dian)(dian)(dian)池(chi)待(dai)充(chong)電(dian)(dian)(dian)的(de)(de)(de)安時數(shu)。實際上，常規(gui)(gui)充(chong)電(dian)(dian)(dian)的(de)(de)(de)速度被(bei)蓄電(dian)(dian)(dian)池(chi)在充(chong)電(dian)(dian)(dian)過程中(zhong)的(de)(de)(de)溫升(sheng)和氣體的(de)(de)(de)產生所限制。這(zhe)個現象對蓄電(dian)(dian)(dian)池(chi)充(chong)電(dian)(dian)(dian)所必須的(de)(de)(de)最短時間具有重要意(yi)義。
一(yi)般來(lai)說，常(chang)規充電有以下3種。
2.1.1 恒流(liu)充電法
恒流充(chong)(chong)電(dian)(dian)法是(shi)用(yong)調整充(chong)(chong)電(dian)(dian)裝置輸出電(dian)(dian)壓或(huo)改變與蓄電(dian)(dian)池串聯電(dian)(dian)阻(zu)的方法，保持充(chong)(chong)電(dian)(dian)電(dian)(dian)流強度(du)不變的充(chong)(chong)電(dian)(dian)方法，如圖2所示。控制方法簡單，但由于(yu)(yu)電(dian)(dian)池的可接受電(dian)(dian)流能(neng)力是(shi)隨(sui)著(zhu)充(chong)(chong)電(dian)(dian)過(guo)程的進行而逐漸下降的，到充(chong)(chong)電(dian)(dian)后期，充(chong)(chong)電(dian)(dian)電(dian)(dian)流多用(yong)于(yu)(yu)電(dian)(dian)解水，產生氣體，使出氣過(guo)甚，因此，常選用(yong)階段充(chong)(chong)電(dian)(dian)法。
圖(tu)2 恒(heng)流充電曲線
2.1.2 階段(duan)充(chong)電法
此(ci)方(fang)法包括二階段(duan)充(chong)(chong)電法和三階段(duan)充(chong)(chong)電法。
1）二階(jie)(jie)段(duan)(duan)法 采用恒電(dian)流和(he)恒電(dian)壓相(xiang)結合的(de)快速充電(dian)方法，如圖(tu)3所示。首先，以恒電(dian)流充電(dian)至預(yu)定(ding)的(de)電(dian)壓值(zhi)，然后，改(gai)為恒電(dian)壓完(wan)成剩余的(de)充電(dian)。一般兩階(jie)(jie)段(duan)(duan)之間的(de)轉換電(dian)壓就是第(di)二階(jie)(jie)段(duan)(duan)的(de)恒電(dian)壓。
圖3 二階段法(fa)曲線
2）三階(jie)(jie)段(duan)充(chong)(chong)電(dian)法(fa) 在充(chong)(chong)電(dian)開始和結束(shu)時(shi)采用(yong)(yong)恒(heng)電(dian)流充(chong)(chong)電(dian)，中間用(yong)(yong)恒(heng)電(dian)壓(ya)充(chong)(chong)電(dian)。當(dang)電(dian)流衰減到預(yu)定值時(shi)，由第二(er)階(jie)(jie)段(duan)轉換到第三階(jie)(jie)段(duan)。這種(zhong)方法(fa)可以將(jiang)出氣(qi)量減到最少，但作為一種(zhong)快速充(chong)(chong)電(dian)方法(fa)使用(yong)(yong)，受到一定的限制。
2.1.3 恒壓充電法(fa)
充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)源的(de)電(dian)(dian)(dian)壓在全部充(chong)(chong)電(dian)(dian)(dian)時(shi)間里保(bao)持恒定的(de)數(shu)值，隨(sui)著蓄電(dian)(dian)(dian)池端電(dian)(dian)(dian)壓的(de)逐漸(jian)升高，電(dian)(dian)(dian)流(liu)(liu)逐漸(jian)減少。與(yu)恒流(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)法相比，其(qi)充(chong)(chong)電(dian)(dian)(dian)過程更接近(jin)于最(zui)佳充(chong)(chong)電(dian)(dian)(dian)曲線(xian)。用恒定電(dian)(dian)(dian)壓快速(su)充(chong)(chong)電(dian)(dian)(dian)，如圖4所示。由(you)于充(chong)(chong)電(dian)(dian)(dian)初期蓄電(dian)(dian)(dian)池電(dian)(dian)(dian)動勢較低，充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)很大，隨(sui)著充(chong)(chong)電(dian)(dian)(dian)的(de)進行，電(dian)(dian)(dian)流(liu)(liu)將逐漸(jian)減少，因此，只需簡易控制系統(tong)。
圖(tu)4 ; 恒(heng)壓(ya)充電法曲線(xian)
這種充電(dian)(dian)(dian)方法電(dian)(dian)(dian)解(jie)水很少，避免了蓄(xu)電(dian)(dian)(dian)池過充。但在充電(dian)(dian)(dian)初期電(dian)(dian)(dian)流過大(da)，對蓄(xu)電(dian)(dian)(dian)池壽命造(zao)成很大(da)影響(xiang)，且(qie)容易使蓄(xu)電(dian)(dian)(dian)池極板彎(wan)曲，造(zao)成電(dian)(dian)(dian)池報廢。
鑒于這種缺點(dian)，恒壓充(chong)電(dian)(dian)很少使用，只有在充(chong)電(dian)(dian)電(dian)(dian)源電(dian)(dian)壓低而電(dian)(dian)流大時采(cai)用。例(li)如，汽車(che)運(yun)行過程(cheng)中，蓄電(dian)(dian)池就是以恒壓充(chong)電(dian)(dian)法充(chong)電(dian)(dian)的。
2.2 快(kuai)速充電技術
為了(le)(le)能夠最大限度地加快蓄電(dian)池(chi)的(de)(de)化(hua)學反(fan)應速(su)度，縮短蓄電(dian)池(chi)達到(dao)滿(man)充(chong)狀(zhuang)態的(de)(de)時間，同(tong)時，保證蓄電(dian)池(chi)正負極(ji)板的(de)(de)極(ji)化(hua)現(xian)象盡量地少(shao)或輕(qing)，提高蓄電(dian)池(chi)使用效率。快速(su)充(chong)電(dian)技術近年來(lai)得到(dao)了(le)(le)迅速(su)發展。
下面介紹目前比較流行的(de)(de)幾種快速充(chong)電方法。這些方法都(dou)是圍(wei)繞著最(zui)佳充(chong)電曲(qu)線進(jin)行設(she)計的(de)(de)，目的(de)(de)就是使其充(chong)電曲(qu)線盡(jin)可能地逼進(jin)最(zui)佳充(chong)電曲(qu)線。
2.2.1 脈(mo)沖式(shi)充電(dian)法
這種(zhong)充(chong)電法不僅遵循蓄(xu)電池(chi)固(gu)有的(de)充(chong)電接受率，而(er)且能夠提高蓄(xu)電池(chi)充(chong)電接受率，從而(er)打破了蓄(xu)電池(chi)指數(shu)充(chong)電接受曲(qu)線的(de)限制，這也是蓄(xu)電池(chi)充(chong)電理論的(de)新發展。
脈沖(chong)充(chong)(chong)電(dian)(dian)(dian)(dian)方式(shi)首先是用脈沖(chong)電(dian)(dian)(dian)(dian)流(liu)對電(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)，然后讓(rang)電(dian)(dian)(dian)(dian)池(chi)停(ting)充(chong)(chong)一(yi)段時間(jian)，如此(ci)循環，如圖5所示。充(chong)(chong)電(dian)(dian)(dian)(dian)脈沖(chong)使(shi)蓄電(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)滿(man)電(dian)(dian)(dian)(dian)量(liang)，而(er)(er)間(jian)歇期使(shi)蓄電(dian)(dian)(dian)(dian)池(chi)經化(hua)學反應產生(sheng)的(de)氧氣和(he)氫氣有時間(jian)重新化(hua)合而(er)(er)被吸收(shou)掉，使(shi)濃(nong)差(cha)極化(hua)和(he)歐姆極化(hua)自然而(er)(er)然地(di)得到消除(chu)，從而(er)(er)減(jian)輕了(le)(le)蓄電(dian)(dian)(dian)(dian)池(chi)的(de)內壓，使(shi)下一(yi)輪的(de)恒流(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)能夠(gou)更加順利(li)地(di)進行，使(shi)蓄電(dian)(dian)(dian)(dian)池(chi)可以吸收(shou)更多(duo)的(de)電(dian)(dian)(dian)(dian)量(liang)。間(jian)歇脈沖(chong)使(shi)蓄電(dian)(dian)(dian)(dian)池(chi)有較充(chong)(chong)分的(de)反應時間(jian)，減(jian)少了(le)(le)析氣量(liang)，提高了(le)(le)蓄電(dian)(dian)(dian)(dian)池(chi)的(de)充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)接受率[5]。
圖5 脈沖式充電(dian)曲線
2.2.2 ReflexTM快速充電(dian)法
這(zhe)種技術(shu)(shu)是(shi)美(mei)國的(de)(de)(de)一項專利(li)技術(shu)(shu)，它(ta)主要(yao)面對(dui)的(de)(de)(de)充電(dian)(dian)(dian)(dian)對(dui)象是(shi)鎳(nie)鎘電(dian)(dian)(dian)(dian)池(chi)(chi)。由于它(ta)采用了新型的(de)(de)(de)充電(dian)(dian)(dian)(dian)方(fang)法(fa)，解決了鎳(nie)鎘電(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)(de)記憶效應，因此，大大降(jiang)低(di)了蓄電(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)(de)快速(su)充電(dian)(dian)(dian)(dian)的(de)(de)(de)時間。鉛酸蓄電(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)(de)充電(dian)(dian)(dian)(dian)方(fang)法(fa)和對(dui)充電(dian)(dian)(dian)(dian)狀態(tai)的(de)(de)(de)檢測方(fang)法(fa)與鎳(nie)鎘電(dian)(dian)(dian)(dian)池(chi)(chi)有很大的(de)(de)(de)不同，但(dan)它(ta)們之間可以(yi)相互借(jie)鑒(jian)[3]。
如圖6所(suo)示，ReflexTM充(chong)(chong)電法(fa)的一個工作周期(qi)包(bao)括(kuo)正向充(chong)(chong)電脈(mo)沖(chong)，反向瞬(shun)間(jian)放電脈(mo)沖(chong)，停充(chong)(chong)維持3個階段(duan)[3]。
圖6 ReflexTM快速充電法
2.2.3 變電流間歇充電法
這種充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)方法建立在(zai)恒(heng)(heng)流(liu)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)和(he)脈沖充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)的(de)基礎上，如圖7所示。其特(te)點是(shi)將(jiang)(jiang)恒(heng)(heng)流(liu)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)段(duan)改為限壓變(bian)電(dian)流(liu)間歇充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)段(duan)。充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)前(qian)期的(de)各段(duan)采用(yong)變(bian)電(dian)流(liu)間歇充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)的(de)方法，保證加(jia)大(da)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)電(dian)流(liu)，獲得(de)絕(jue)大(da)部(bu)分充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)量。充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)后期采用(yong)定電(dian)壓充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)段(duan)，獲得(de)過充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)量，將(jiang)(jiang)電(dian)池(chi)恢復至完(wan)全(quan)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)態。通過間歇停充(chong)(chong)(chong)(chong)(chong)(chong)，使(shi)(shi)蓄(xu)電(dian)池(chi)經化學反(fan)應產生(sheng)的(de)氧(yang)氣和(he)氫氣有(you)時間重新化合而(er)被吸(xi)收掉，使(shi)(shi)濃差極(ji)化和(he)歐(ou)姆極(ji)化自然而(er)然地得(de)到消除，從而(er)減輕了蓄(xu)電(dian)池(chi)的(de)內壓，使(shi)(shi)下一(yi)輪的(de)恒(heng)(heng)流(liu)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)能(neng)夠更(geng)加(jia)順利(li)地進行，使(shi)(shi)蓄(xu)電(dian)池(chi)可(ke)以吸(xi)收更(geng)多的(de)電(dian)量[4]。
圖(tu)7 變電流(liu)間歇(xie)充電曲(qu)線
2.2.4 變電壓間(jian)歇(xie)充電法(fa)
在變電(dian)流間歇(xie)(xie)充電(dian)法的基礎上(shang)又有人提出(chu)了變電(dian)壓間歇(xie)(xie)充電(dian)法，如圖8所示。與(yu)變電(dian)流間歇(xie)(xie)充電(dian)方(fang)法不(bu)(bu)同之處(chu)在于第(di)一(yi)階段的不(bu)(bu)是間歇(xie)(xie)恒流，而是間歇(xie)(xie)恒壓。
圖8 變(bian)電壓間歇充電曲線(xian)
比(bi)較圖(tu)7和圖(tu)8，可(ke)以看(kan)出：圖(tu)8更加符(fu)合最佳(jia)充(chong)電(dian)(dian)的充(chong)電(dian)(dian)曲線(xian)。在每個恒(heng)電(dian)(dian)壓(ya)充(chong)電(dian)(dian)階段，由于是恒(heng)壓(ya)充(chong)電(dian)(dian)，充(chong)電(dian)(dian)電(dian)(dian)流(liu)自然按照指數規律下降，符(fu)合電(dian)(dian)池電(dian)(dian)流(liu)可(ke)接(jie)受率隨著充(chong)電(dian)(dian)的進行逐(zhu)漸下降的特點[4]。
2.2.5 ; 變電壓變電流波浪式間歇正負(fu)零脈(mo)沖快(kuai)速充電法
綜(zong)合脈沖(chong)(chong)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)法(fa)、ReflexTM快速充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)法(fa)、變電(dian)(dian)(dian)(dian)流間歇充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)法(fa)及變電(dian)(dian)(dian)(dian)壓間歇充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)法(fa)的優(you)點，變電(dian)(dian)(dian)(dian)壓變電(dian)(dian)(dian)(dian)流波(bo)浪式正負零脈沖(chong)(chong)間歇快速充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)法(fa)得到發展(zhan)應用。脈沖(chong)(chong)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)法(fa)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)路的控制一般有兩種：
1）脈沖電流的幅值可變，而PWM（驅動充放電開關管）信號(hao)的頻率是固定的；
2）脈沖電流幅值固定不變，PWM信號(hao)的頻率可調。
圖9采用(yong)了一種不同于(yu)這兩者的(de)控制模(mo)式(shi)，脈沖電(dian)流(liu)幅值和PWM信號的(de)頻率均(jun)固定(ding)，PWM占空比可調，在此基(ji)礎(chu)上(shang)加入間(jian)歇(xie)停(ting)充階(jie)段，能夠在較(jiao)短的(de)時間(jian)內充進更多的(de)電(dian)量，提高蓄電(dian)池的(de)充電(dian)接受能力。
圖(tu)9 波(bo)浪(lang)式間歇正負零脈沖快(kuai)速充(chong)電(dian)
3 結語
鉛(qian)酸蓄電池是(shi)(shi)目前(qian)世界上(shang)廣泛(fan)使用(yong)(yong)的一(yi)種(zhong)化學電源，該產品(pin)具有(you)良好的可逆(ni)性(xing)，電壓特性(xing)平穩，使用(yong)(yong)壽命(ming)長(chang)，適用(yong)(yong)范圍廣，原材料豐富（且(qie)可再(zai)生使用(yong)(yong)）及(ji)造價低(di)廉等優(you)點。主(zhu)要應用(yong)(yong)在交通運(yun)輸(shu)，通信，電力，鐵路(lu)，礦山(shan)，港口等國民經濟各個(ge)部門，是(shi)(shi)社會(hui)生產經營活動中不可缺(que)少的產品(pin)，具有(you)廣闊的發展(zhan)前(qian)景。