鉛酸蓄電池充電機充電原理示意圖
鉛酸蓄(xu)電池(chi)由于(yu)其制造成本低，容量大，價格低廉(lian)而得到了廣(guang)泛的(de)(de)(de)使用。但是，若使用不(bu)當，其壽命(ming)將大大縮短(duan)。影響鉛酸蓄(xu)電池(chi)壽命(ming)的(de)(de)(de)因(yin)素很(hen)多，而采(cai)用正確的(de)(de)(de)充電方式，能有(you)效延長蓄(xu)電池(chi)的(de)(de)(de)使用壽命(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(dui)蓄電(dian)池的(de)使用(yong)壽命(ming)具(ju)有舉足(zu)輕重的(de)作用(yong)。
1 蓄(xu)電池充電理論(lun)基礎(chu)
上世(shi)紀60年代中期，美(mei)國(guo)科學(xue)家馬斯(si)對開口(kou)蓄(xu)電池的(de)(de)充(chong)(chong)電過程作了大(da)量的(de)(de)試驗研究，并(bing)提出了以(yi)最(zui)(zui)低出氣率(lv)為(wei)前提的(de)(de)，蓄(xu)電池可接受的(de)(de)充(chong)(chong)電曲(qu)線，如(ru)圖1所示。實驗表明，如(ru)果充(chong)(chong)電電流(liu)按這條曲(qu)線變化，就可以(yi)大(da)大(da)縮短充(chong)(chong)電時間，并(bing)且對電池的(de)(de)容量和壽(shou)命也(ye)沒有影(ying)響。原則(ze)上把這條曲(qu)線稱為(wei)最(zui)(zui)佳充(chong)(chong)電曲(qu)線，從(cong)而奠定了快速(su)充(chong)(chong)電方法的(de)(de)研究方向(xiang)[1，2]。
圖1最佳充電曲線
由圖1可以(yi)看出(chu)：初始充(chong)電(dian)(dian)電(dian)(dian)流很大(da)(da)，但是衰減很快。主要原因是充(chong)電(dian)(dian)過程(cheng)中(zhong)產生(sheng)了極化現象(xiang)。在(zai)密封(feng)式蓄電(dian)(dian)池(chi)充(chong)電(dian)(dian)過程(cheng)中(zhong)，內(nei)部(bu)產生(sheng)氧(yang)(yang)氣(qi)(qi)和氫氣(qi)(qi)，當氧(yang)(yang)氣(qi)(qi)不能被及時(shi)吸收時(shi)，便堆積在(zai)正極板(ban)（正極板(ban)產生(sheng)氧(yang)(yang)氣(qi)(qi)），使(shi)電(dian)(dian)池(chi)內(nei)部(bu)壓力加大(da)(da)，電(dian)(dian)池(chi)溫度上升，同時(shi)縮(suo)小了正極板(ban)的面積，表現為內(nei)阻上升，出(chu)現所謂的極化現象(xiang)。
蓄電池是可逆的(de)。其放電及充(chong)電的(de)化學(xue)反應(ying)式如下：
PbO2＋Pb＋2H2SO42PbSO4＋2H2O （1）
很顯(xian)然(ran)，充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)過(guo)程和放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)過(guo)程互為(wei)逆反(fan)應(ying)。可逆過(guo)程就是(shi)熱力學(xue)的平(ping)衡(heng)過(guo)程，為(wei)保障電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)能夠(gou)始終(zhong)維持在(zai)平(ping)衡(heng)狀態之下充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，必(bi)須盡量使通過(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流小一些。理(li)想(xiang)條件是(shi)外加電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓等于電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)本身的電(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)勢(shi)(shi)。但(dan)是(shi)，實踐(jian)表明，蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)時，外加電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓必(bi)須增大到一定數值(zhi)才行,而這(zhe)個數值(zhi)又因為(wei)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極材(cai)料(liao)，溶液濃(nong)度(du)等各種因素的差別而在(zai)不同程度(du)上超(chao)過(guo)了蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的平(ping)衡(heng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)勢(shi)(shi)值(zhi)。在(zai)化(hua)學(xue)反(fan)應(ying)中，這(zhe)種電(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)勢(shi)(shi)超(chao)過(guo)熱力學(xue)平(ping)衡(heng)值(zhi)的現(xian)象，就是(shi)極化(hua)現(xian)象。
一般來說(shuo)，產(chan)生極化現象有3個方(fang)面(mian)的原因。
1）歐姆極化(hua)(hua) 充(chong)(chong)電(dian)(dian)過(guo)程(cheng)中，正負離子(zi)向兩極遷移(yi)。在(zai)離子(zi)遷移(yi)過(guo)程(cheng)中不可避免地(di)受到一定(ding)的(de)阻(zu)(zu)力(li)，稱為歐姆內阻(zu)(zu)。為了克服這(zhe)個內阻(zu)(zu)，外加(jia)電(dian)(dian)壓就(jiu)必須(xu)額(e)外施(shi)加(jia)一定(ding)的(de)電(dian)(dian)壓，以克服阻(zu)(zu)力(li)推動離子(zi)遷移(yi)。該電(dian)(dian)壓以熱(re)的(de)方式轉化(hua)(hua)給(gei)環境，出(chu)現所謂(wei)的(de)歐姆極化(hua)(hua)。隨著充(chong)(chong)電(dian)(dian)電(dian)(dian)流急(ji)劇加(jia)大，歐姆極化(hua)(hua)將造成蓄電(dian)(dian)池(chi)在(zai)充(chong)(chong)電(dian)(dian)過(guo)程(cheng)中的(de)高(gao)溫。
2）濃度(du)(du)(du)(du)極(ji)(ji)化 電(dian)流(liu)流(liu)過蓄電(dian)池時，為(wei)維持(chi)正(zheng)常(chang)的反應(ying)，最理想(xiang)的情況(kuang)是電(dian)極(ji)(ji)表面的反應(ying)物能及時得到補充(chong)，生(sheng)成(cheng)(cheng)(cheng)物能及時離去。實際(ji)上，生(sheng)成(cheng)(cheng)(cheng)物和反應(ying)物的擴散速(su)度(du)(du)(du)(du)遠遠比不(bu)(bu)上化學反應(ying)速(su)度(du)(du)(du)(du)，從(cong)而(er)造成(cheng)(cheng)(cheng)極(ji)(ji)板附近電(dian)解(jie)質溶液濃度(du)(du)(du)(du)發生(sheng)變化。也就是說(shuo)，從(cong)電(dian)極(ji)(ji)表面到中部溶液，電(dian)解(jie)液濃度(du)(du)(du)(du)分布不(bu)(bu)均勻。這種現象稱為(wei)濃度(du)(du)(du)(du)極(ji)(ji)化。
3）電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)化(hua)(hua)學(xue)(xue)極(ji)(ji)(ji)(ji)(ji)(ji)化(hua)(hua) 這種極(ji)(ji)(ji)(ji)(ji)(ji)化(hua)(hua)是(shi)(shi)由于電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)上(shang)進(jin)行(xing)(xing)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)化(hua)(hua)學(xue)(xue)反應的(de)(de)(de)速(su)度，落后于電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)上(shang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)運動的(de)(de)(de)速(su)度造成(cheng)的(de)(de)(de)。例如：電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池的(de)(de)(de)負(fu)極(ji)(ji)(ji)(ji)(ji)(ji)放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)前，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)表(biao)面帶有(you)(you)負(fu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)荷，其附近溶(rong)(rong)液帶有(you)(you)正電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)荷，兩者處(chu)于平(ping)衡(heng)狀(zhuang)態。放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)，立即有(you)(you)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)釋放給外電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)表(biao)面負(fu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)荷減少(shao)(shao)，而(er)金屬(shu)(shu)溶(rong)(rong)解(jie)的(de)(de)(de)氧化(hua)(hua)反應進(jin)行(xing)(xing)緩(huan)慢Me－e→Me＋，不能及時(shi)補(bu)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)表(biao)面電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)的(de)(de)(de)減少(shao)(shao)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)表(biao)面帶電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)狀(zhuang)態發生變化(hua)(hua)。這種表(biao)面負(fu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)荷減少(shao)(shao)的(de)(de)(de)狀(zhuang)態促(cu)進(jin)金屬(shu)(shu)中電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)離開(kai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)，金屬(shu)(shu)離子(zi)(zi)Me＋轉入(ru)溶(rong)(rong)液，加速(su)Me－e→Me＋反應進(jin)行(xing)(xing)。總有(you)(you)一個(ge)時(shi)刻，達到新的(de)(de)(de)動態平(ping)衡(heng)。但與放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)前相比，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)表(biao)面所(suo)帶負(fu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)荷數目減少(shao)(shao)了，與此對應的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)勢變正。也就(jiu)是(shi)(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)化(hua)(hua)學(xue)(xue)極(ji)(ji)(ji)(ji)(ji)(ji)化(hua)(hua)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓變高，從而(er)嚴重阻礙了正常的(de)(de)(de)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流。同理，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池正極(ji)(ji)(ji)(ji)(ji)(ji)放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)表(biao)面所(suo)帶正電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)荷數目減少(shao)(shao)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)(ji)(ji)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)勢變負(fu)。
這3種極化(hua)現象都是隨著充(chong)電(dian)電(dian)流的增大而(er)嚴(yan)重。
2 充電方法的(de)研究
2.1 常規(gui)充(chong)電法
常(chang)(chang)規充(chong)(chong)電(dian)制度(du)是依據1940年前國際公認的(de)(de)經驗法則設計(ji)的(de)(de)。其(qi)中(zhong)最著名的(de)(de)就是“安(an)培小(xiao)時(shi)(shi)(shi)規則”：充(chong)(chong)電(dian)電(dian)流安(an)培數(shu)，不應超過蓄電(dian)池待充(chong)(chong)電(dian)的(de)(de)安(an)時(shi)(shi)(shi)數(shu)。實際上，常(chang)(chang)規充(chong)(chong)電(dian)的(de)(de)速度(du)被蓄電(dian)池在充(chong)(chong)電(dian)過程中(zhong)的(de)(de)溫升(sheng)和氣體的(de)(de)產(chan)生所限制。這(zhe)個現象對蓄電(dian)池充(chong)(chong)電(dian)所必須的(de)(de)最短時(shi)(shi)(shi)間具有重要意義。
一般來說(shuo)，常規充電有以下3種。
2.1.1 恒流充電法(fa)
恒流(liu)充(chong)電(dian)(dian)(dian)(dian)法(fa)是用調(diao)整充(chong)電(dian)(dian)(dian)(dian)裝置輸出電(dian)(dian)(dian)(dian)壓或(huo)改(gai)變(bian)與蓄電(dian)(dian)(dian)(dian)池(chi)串聯(lian)電(dian)(dian)(dian)(dian)阻的(de)(de)方法(fa)，保持充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)強度不(bu)變(bian)的(de)(de)充(chong)電(dian)(dian)(dian)(dian)方法(fa)，如圖2所(suo)示(shi)。控制方法(fa)簡單，但(dan)由于(yu)電(dian)(dian)(dian)(dian)池(chi)的(de)(de)可接受電(dian)(dian)(dian)(dian)流(liu)能(neng)力(li)是隨著充(chong)電(dian)(dian)(dian)(dian)過程的(de)(de)進行而逐漸下降的(de)(de)，到充(chong)電(dian)(dian)(dian)(dian)后期，充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)多用于(yu)電(dian)(dian)(dian)(dian)解水(shui)，產生氣體，使出氣過甚(shen)，因此(ci)，常(chang)選用階(jie)段充(chong)電(dian)(dian)(dian)(dian)法(fa)。
圖2 恒流充電曲(qu)線
2.1.2 階段充(chong)電(dian)法
此方(fang)法(fa)包括二階段充(chong)(chong)電法(fa)和三階段充(chong)(chong)電法(fa)。
1）二階段(duan)法 采用恒(heng)電(dian)(dian)流(liu)和恒(heng)電(dian)(dian)壓相結合的(de)(de)快速充電(dian)(dian)方法，如(ru)圖(tu)3所示。首先(xian)，以恒(heng)電(dian)(dian)流(liu)充電(dian)(dian)至預(yu)定的(de)(de)電(dian)(dian)壓值，然后(hou)，改為恒(heng)電(dian)(dian)壓完成剩余的(de)(de)充電(dian)(dian)。一般(ban)兩階段(duan)之間的(de)(de)轉換電(dian)(dian)壓就(jiu)是第(di)二階段(duan)的(de)(de)恒(heng)電(dian)(dian)壓。
圖3 二階(jie)段法曲線(xian)
2）三(san)階(jie)段充(chong)電法 在(zai)充(chong)電開始和結束時采用(yong)恒電流(liu)充(chong)電，中間用(yong)恒電壓充(chong)電。當電流(liu)衰(shuai)減(jian)到(dao)預(yu)定值時，由第二階(jie)段轉(zhuan)換(huan)到(dao)第三(san)階(jie)段。這(zhe)種(zhong)(zhong)方法可(ke)以將出氣(qi)量減(jian)到(dao)最少(shao)，但(dan)作(zuo)為一種(zhong)(zhong)快(kuai)速(su)充(chong)電方法使用(yong)，受到(dao)一定的限(xian)制。
2.1.3 恒壓(ya)充電法
充電(dian)(dian)(dian)電(dian)(dian)(dian)源的(de)電(dian)(dian)(dian)壓在全(quan)部(bu)充電(dian)(dian)(dian)時(shi)間里保持(chi)恒定的(de)數值，隨著蓄(xu)電(dian)(dian)(dian)池端電(dian)(dian)(dian)壓的(de)逐(zhu)漸(jian)(jian)升高，電(dian)(dian)(dian)流(liu)逐(zhu)漸(jian)(jian)減(jian)(jian)少(shao)。與(yu)恒流(liu)充電(dian)(dian)(dian)法相比，其充電(dian)(dian)(dian)過程更接近于(yu)(yu)最(zui)佳充電(dian)(dian)(dian)曲(qu)線。用恒定電(dian)(dian)(dian)壓快速充電(dian)(dian)(dian)，如圖4所示。由于(yu)(yu)充電(dian)(dian)(dian)初期(qi)蓄(xu)電(dian)(dian)(dian)池電(dian)(dian)(dian)動勢較低，充電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)很大，隨著充電(dian)(dian)(dian)的(de)進行，電(dian)(dian)(dian)流(liu)將逐(zhu)漸(jian)(jian)減(jian)(jian)少(shao)，因(yin)此，只(zhi)需簡易控制系統。
圖4 恒(heng)壓充電法曲(qu)線
這種充電(dian)(dian)方法(fa)電(dian)(dian)解水很少，避免(mian)了蓄電(dian)(dian)池過(guo)充。但在充電(dian)(dian)初期電(dian)(dian)流(liu)過(guo)大(da)，對蓄電(dian)(dian)池壽命造成很大(da)影(ying)響(xiang)，且容易(yi)使(shi)蓄電(dian)(dian)池極板彎(wan)曲，造成電(dian)(dian)池報(bao)廢。
鑒(jian)于這種缺點，恒(heng)壓(ya)(ya)充電(dian)(dian)(dian)很少使用，只有在充電(dian)(dian)(dian)電(dian)(dian)(dian)源電(dian)(dian)(dian)壓(ya)(ya)低而電(dian)(dian)(dian)流大時采用。例如，汽(qi)車運行過程中，蓄(xu)電(dian)(dian)(dian)池就是以(yi)恒(heng)壓(ya)(ya)充電(dian)(dian)(dian)法充電(dian)(dian)(dian)的。
2.2 快速充電(dian)技(ji)術
為(wei)了能夠最(zui)大限(xian)度地加快(kuai)蓄(xu)電(dian)池的(de)化學反應速(su)度，縮短蓄(xu)電(dian)池達到滿充(chong)狀態(tai)的(de)時(shi)間，同時(shi)，保證(zheng)蓄(xu)電(dian)池正負極板的(de)極化現象(xiang)盡量地少或輕(qing)，提高蓄(xu)電(dian)池使用效率。快(kuai)速(su)充(chong)電(dian)技術近年來(lai)得到了迅速(su)發展。
下面(mian)介(jie)紹目前比較流行的幾種快速充電方法。這(zhe)些方法都是(shi)圍繞著最佳充電曲(qu)線進行設計的，目的就是(shi)使其充電曲(qu)線盡可(ke)能地逼進最佳充電曲(qu)線。
2.2.1 脈沖(chong)式(shi)充電(dian)法
這(zhe)種充(chong)(chong)(chong)電法不僅遵循蓄電池(chi)(chi)固有的(de)(de)充(chong)(chong)(chong)電接(jie)(jie)受(shou)率，而(er)且能夠提高(gao)蓄電池(chi)(chi)充(chong)(chong)(chong)電接(jie)(jie)受(shou)率，從而(er)打破了蓄電池(chi)(chi)指數(shu)充(chong)(chong)(chong)電接(jie)(jie)受(shou)曲線的(de)(de)限制，這(zhe)也是(shi)蓄電池(chi)(chi)充(chong)(chong)(chong)電理論的(de)(de)新發展。
脈沖充(chong)(chong)電(dian)(dian)(dian)方式首先是用(yong)脈沖電(dian)(dian)(dian)流(liu)對電(dian)(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)(dian)，然(ran)(ran)后讓電(dian)(dian)(dian)池(chi)停(ting)充(chong)(chong)一段時(shi)間，如(ru)此循(xun)環(huan)，如(ru)圖5所示。充(chong)(chong)電(dian)(dian)(dian)脈沖使蓄(xu)電(dian)(dian)(dian)池(chi)充(chong)(chong)滿電(dian)(dian)(dian)量(liang)，而間歇(xie)期使蓄(xu)電(dian)(dian)(dian)池(chi)經化(hua)學反應產生的(de)氧氣和氫氣有(you)時(shi)間重新化(hua)合(he)而被(bei)吸收掉，使濃差極(ji)化(hua)和歐姆極(ji)化(hua)自然(ran)(ran)而然(ran)(ran)地得到消除，從而減輕了蓄(xu)電(dian)(dian)(dian)池(chi)的(de)內壓，使下一輪的(de)恒流(liu)充(chong)(chong)電(dian)(dian)(dian)能夠(gou)更加順(shun)利地進行，使蓄(xu)電(dian)(dian)(dian)池(chi)可以(yi)吸收更多的(de)電(dian)(dian)(dian)量(liang)。間歇(xie)脈沖使蓄(xu)電(dian)(dian)(dian)池(chi)有(you)較(jiao)充(chong)(chong)分的(de)反應時(shi)間，減少了析氣量(liang)，提高了蓄(xu)電(dian)(dian)(dian)池(chi)的(de)充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)接(jie)受(shou)率(lv)[5]。
圖5 脈沖式充電曲線(xian)
2.2.2 ReflexTM快速充電法
這(zhe)種技(ji)術(shu)是美(mei)國(guo)的一項專利技(ji)術(shu)，它主要面(mian)對的充電(dian)(dian)對象是鎳鎘電(dian)(dian)池(chi)。由(you)于它采用(yong)了新型(xing)的充電(dian)(dian)方(fang)法(fa)，解決了鎳鎘電(dian)(dian)池(chi)的記憶效應，因此，大大降低了蓄電(dian)(dian)池(chi)的快速充電(dian)(dian)的時間(jian)。鉛(qian)酸蓄電(dian)(dian)池(chi)的充電(dian)(dian)方(fang)法(fa)和(he)對充電(dian)(dian)狀(zhuang)態的檢測方(fang)法(fa)與(yu)鎳鎘電(dian)(dian)池(chi)有很大的不同，但它們之間(jian)可以相互借鑒[3]。
如圖6所示，ReflexTM充(chong)電(dian)法的一個(ge)工作周期(qi)包括正向(xiang)充(chong)電(dian)脈沖，反(fan)向(xiang)瞬間放電(dian)脈沖，停充(chong)維持3個(ge)階段[3]。
圖6 ReflexTM快速充電法
2.2.3 變電流間歇(xie)充電法
這種充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)方法建立(li)在(zai)恒流(liu)(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)和脈沖(chong)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)的(de)基礎上，如圖7所(suo)示。其特點是將恒流(liu)(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)段(duan)改為(wei)限(xian)壓(ya)變電(dian)(dian)(dian)(dian)流(liu)(liu)間(jian)(jian)歇(xie)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)段(duan)。充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)前(qian)期(qi)的(de)各段(duan)采用(yong)(yong)變電(dian)(dian)(dian)(dian)流(liu)(liu)間(jian)(jian)歇(xie)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)的(de)方法，保證加大(da)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)(liu)，獲得(de)絕大(da)部分充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)量。充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)后(hou)期(qi)采用(yong)(yong)定電(dian)(dian)(dian)(dian)壓(ya)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)段(duan)，獲得(de)過充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)量，將電(dian)(dian)(dian)(dian)池(chi)恢復至完全充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)態。通過間(jian)(jian)歇(xie)停充(chong)(chong)(chong)，使蓄(xu)電(dian)(dian)(dian)(dian)池(chi)經化學反(fan)應產生的(de)氧氣和氫(qing)氣有時間(jian)(jian)重(zhong)新(xin)化合而(er)被吸收(shou)掉(diao)，使濃差極化和歐姆(mu)極化自然而(er)然地(di)(di)得(de)到消除(chu)，從而(er)減輕(qing)了蓄(xu)電(dian)(dian)(dian)(dian)池(chi)的(de)內壓(ya)，使下一輪的(de)恒流(liu)(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)能夠(gou)更加順利地(di)(di)進(jin)行，使蓄(xu)電(dian)(dian)(dian)(dian)池(chi)可以吸收(shou)更多的(de)電(dian)(dian)(dian)(dian)量[4]。
圖(tu)7 變電(dian)流間歇充電(dian)曲(qu)線
2.2.4 變電(dian)壓間歇(xie)充電(dian)法
在變電(dian)(dian)流間歇(xie)(xie)充電(dian)(dian)法(fa)的(de)基礎上又有人(ren)提(ti)出了變電(dian)(dian)壓間歇(xie)(xie)充電(dian)(dian)法(fa)，如圖(tu)8所示。與變電(dian)(dian)流間歇(xie)(xie)充電(dian)(dian)方(fang)法(fa)不(bu)同之處在于第一(yi)階段的(de)不(bu)是間歇(xie)(xie)恒(heng)流，而(er)是間歇(xie)(xie)恒(heng)壓。
圖8 變電壓間歇充電曲線(xian)
比較圖7和圖8，可以(yi)看出：圖8更加(jia)符合(he)最佳充電的(de)(de)充電曲(qu)線。在每個恒電壓(ya)充電階段(duan)，由(you)于是恒壓(ya)充電，充電電流(liu)自然按照指數(shu)規律(lv)下降，符合(he)電池(chi)電流(liu)可接受率隨著充電的(de)(de)進行逐漸下降的(de)(de)特點(dian)[4]。
2.2.5 變電(dian)壓變電(dian)流波浪式間歇正負零(ling)脈沖快速(su)充(chong)電(dian)法
綜合脈沖(chong)充(chong)(chong)電(dian)(dian)法、ReflexTM快(kuai)(kuai)速充(chong)(chong)電(dian)(dian)法、變電(dian)(dian)流間歇(xie)充(chong)(chong)電(dian)(dian)法及變電(dian)(dian)壓間歇(xie)充(chong)(chong)電(dian)(dian)法的(de)優點(dian)，變電(dian)(dian)壓變電(dian)(dian)流波(bo)浪式正負零脈沖(chong)間歇(xie)快(kuai)(kuai)速充(chong)(chong)電(dian)(dian)法得到發展應用。脈沖(chong)充(chong)(chong)電(dian)(dian)法充(chong)(chong)電(dian)(dian)電(dian)(dian)路的(de)控制(zhi)一般有兩種：
1）脈沖電流的幅值可(ke)變，而PWM（驅動充放電開關管）信號的頻率是(shi)固定的；
2）脈沖電(dian)流(liu)幅(fu)值固定不變，PWM信(xin)號的頻率可(ke)調。
圖(tu)9采(cai)用(yong)了一種不同于這兩者的(de)控制(zhi)模式，脈沖電(dian)流幅值和PWM信號(hao)的(de)頻率均固定，PWM占空比(bi)可調(diao)，在此基礎上加入間(jian)歇停(ting)充(chong)階段(duan)，能夠在較短(duan)的(de)時間(jian)內(nei)充(chong)進更(geng)多的(de)電(dian)量，提高蓄(xu)電(dian)池(chi)的(de)充(chong)電(dian)接受能力。
圖(tu)9 波(bo)浪(lang)式(shi)間歇正負零(ling)脈沖快速充(chong)電
3 結(jie)語
鉛酸蓄電池(chi)是目前(qian)世界上廣(guang)泛使(shi)(shi)用(yong)的(de)(de)一種(zhong)化學電源，該產(chan)品具有(you)良好的(de)(de)可(ke)(ke)逆性，電壓特性平穩，使(shi)(shi)用(yong)壽(shou)命長，適(shi)用(yong)范圍(wei)廣(guang)，原材料(liao)豐富（且(qie)可(ke)(ke)再(zai)生使(shi)(shi)用(yong)）及(ji)造價低廉等優點(dian)。主要應用(yong)在(zai)交通(tong)運輸，通(tong)信，電力，鐵路，礦山，港(gang)口(kou)等國民經(jing)濟(ji)各個部(bu)門，是社會(hui)生產(chan)經(jing)營活動中不可(ke)(ke)缺(que)少的(de)(de)產(chan)品，具有(you)廣(guang)闊的(de)(de)發展前(qian)景。