電動自行車（以下簡稱“EB”）產業的興起，對充電器提出了高要求。目前EB所配置的充電器，多屬于傳統的(de)三段(duan)式充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器，三段(duan)式充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器的(de)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)模式是將充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)過程分為恒流、恒壓(ya)、浮充(chong)(chong)(chong)(chong)三個(ge)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)階(jie)段(duan)，以我國(guo)EB采用(yong)較多的(de)36V12Ah鉛酸蓄(xu)電(dian)(dian)(dian)(dian)池組為例(li)，第一階(jie)段(duan)以1.8A的(de)恒定電(dian)(dian)(dian)(dian)流將電(dian)(dian)(dian)(dian)池充(chong)(chong)(chong)(chong)到約44.4V；第二階(jie)段(duan)將充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流減小至(zhi)(zhi)約0.3A，再次(ci)將電(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)壓(ya)充(chong)(chong)(chong)(chong)到44.4V；第三階(jie)段(duan)將電(dian)(dian)(dian)(dian)壓(ya)降至(zhi)(zhi)約41.4V，電(dian)(dian)(dian)(dian)流減至(zhi)(zhi)約50MA對電(dian)(dian)(dian)(dian)池進行浮充(chong)(chong)(chong)(chong)。

　　從幾年來的使用情況看，三段式充電器暴露了(le)一些問題。以(yi)下仍(reng)以(yi)36V12Ah鉛(qian)酸蓄電池(chi)組(zu)為例，談談三段(duan)式充(chong)電器的缺陷和(he)解決方案。

　　三段(duan)式充電(dian)器忽略了電(dian)池的(de)負(fu)溫度特性

　　三段式充電(dian)器充電(dian)參數的設定除受(shou)所配電(dian)池(chi)單體(ti)極板面積(ji)大(da)小、電(dian)極特性、電(dian)解液密度(du)等因素影(ying)響外(wai)，還受(shou)蓄電(dian)池(chi)的環境溫度(du)的影(ying)響。

　　雖然一(yi)直以來，人們都明白電化學(xue)的(de)溫度(du)效應(ying)是(shi)不(bu)能回避的(de)，但(dan)卻(que)在(zai)充電器問題上忽略了。原因可(ke)以有(you)很多，但(dan)特別應(ying)在(zai)此指(zhi)出的(de)是(shi)：過去人們對蓄電池容量(liang)、壽命與(yu)溫度(du)之(zhi)間關系的(de)感觸和認識從來沒有(you)象今(jin)天這樣直接和具體，須知，這是(shi)千萬個(ge)EB用戶參與(yu)了“實驗”的(de)結果。

　　在(zai)我國幾乎所有的(de)(de)地(di)區，使(shi)用無溫(wen)度補償的(de)(de)充電器，都會對電池(chi)造成損害(hai)。夏季過(guo)充，冬季欠(qian)充，過(guo)充和(he)(he)欠(qian)充容(rong)易(yi)(yi)造成電池(chi)失水和(he)(he)硫(liu)(liu)(liu)酸(suan)鹽(yan)(yan)(yan)化，電池(chi)失水后(hou)，硫(liu)(liu)(liu)酸(suan)濃度提高，加劇了板極(ji)腐(fu)蝕，就更(geng)容(rong)易(yi)(yi)產生硫(liu)(liu)(liu)酸(suan)鹽(yan)(yan)(yan)化，硫(liu)(liu)(liu)酸(suan)鹽(yan)(yan)(yan)化的(de)(de)電池(chi)表現為更(geng)容(rong)易(yi)(yi)失水。這(zhe)是一(yi)種(zhong)連鎖反應。鉛酸(suan)電池(chi)硫(liu)(liu)(liu)酸(suan)鹽(yan)(yan)(yan)化是影響EB續(xu)駛里程(cheng)和(he)(he)電池(chi)壽(shou)命的(de)(de)重要因素。

　　無溫度補嘗的(de)(de)(de)充電(dian)器(qi)究竟對(dui)電(dian)池(chi)(chi)的(de)(de)(de)損害有(you)多(duo)大，目前還(huan)缺(que)少實驗數(shu)據(ju)，對(dui)蓄電(dian)池(chi)(chi)進行定(ding)量分析要比定(ding)性分析復雜困難(nan)得(de)多(duo)，但(dan)以下的(de)(de)(de)數(shu)據(ju)可以參考(kao)：EB標準規(gui)定(ding)，鉛(qian)酸(suan)蓄電(dian)池(chi)(chi)的(de)(de)(de)循環次(ci)數(shu)不(bu)(bu)得(de)不(bu)(bu)少于350次(ci)，但(dan)實際上有(you)相當多(duo)的(de)(de)(de)電(dian)池(chi)(chi)使用(yong)時(shi)間不(bu)(bu)到8個(ge)月(yue)，即(ji)循還(huan)次(ci)數(shu)不(bu)(bu)足240次(ci)。

　　充電器增加溫度補償功(gong)能并不困難，如只要將原基準(zhun)電壓改(gai)為具有(you)負溫度系數特性的基準(zhun)電壓，一般就可(ke)以了。

　　三段式(shi)充電(dian)模式(shi)缺少修補(bu)性充電(dian)環節

　　三(san)段式(shi)充(chong)(chong)電(dian)(dian)模式(shi)的(de)恒流――恒壓――浮充(chong)(chong)三(san)個充(chong)(chong)電(dian)(dian)階(jie)段，都是圍繞怎(zen)樣(yang)充(chong)(chong)滿(man)電(dian)(dian)池(chi)(chi)(chi)來設(she)計的(de)，因此，這三(san)個充(chong)(chong)電(dian)(dian)階(jie)段占用了全部(bu)充(chong)(chong)電(dian)(dian)時間，如36V12Ah電(dian)(dian)池(chi)(chi)(chi)組的(de)充(chong)(chong)電(dian)(dian)電(dian)(dian)流通常被設(she)定(ding)為18A，有公式(shi)：12(安時）×1.2（效(xiao)率）÷8（小時）=1.8A。恰好能在標(biao)準規定(ding)的(de)8h內將電(dian)(dian)池(chi)(chi)(chi)充(chong)(chong)滿(man)，設(she)計時就沒打算(suan)留出修補(bu)電(dian)(dian)池(chi)(chi)(chi)的(de)時間，更(geng)何況(kuang)三(san)段式(shi)充(chong)(chong)電(dian)(dian)器(qi)一般也不具備修補(bu)電(dian)(dian)池(chi)(chi)(chi)的(de)功能。

　　產業界向來有(you)人認為：我國的(de)(de)(de)EB以(yi)采(cai)(cai)用(yong)鉛(qian)酸蓄(xu)電(dian)(dian)(dian)池(chi)為主(zhu)，并且采(cai)(cai)取的(de)(de)(de)是(shi)全動(dong)力模式，如電(dian)(dian)(dian)池(chi)長(chang)期不能(neng)達標(biao)，我國的(de)(de)(de)EB產業將可能(neng)有(you)再次夭折的(de)(de)(de)危險(xian)。但技(ji)術界對(dui)此(ci)問(wen)題的(de)(de)(de)認識是(shi)：要想鉛(qian)酸蓄(xu)電(dian)(dian)(dian)池(chi)達標(biao)，除有(you)待于電(dian)(dian)(dian)池(chi)本身的(de)(de)(de)技(ji)術進(jin)(jin)步外，采(cai)(cai)用(yong)充(chong)電(dian)(dian)(dian)與修補(bu)功能(neng)兼備的(de)(de)(de)多功能(neng)充(chong)電(dian)(dian)(dian)器(qi)是(shi)解決問(wen)題的(de)(de)(de)有(you)效途徑。因此(ci)，我們建議立(li)即從以(yi)下兩方(fang)面(mian)入手對(dui)EB充(chong)電(dian)(dian)(dian)器(qi)進(jin)(jin)行技(ji)術改造(zao)。一(yi)是(shi)將36V12Ah電(dian)(dian)(dian)池(chi)組的(de)(de)(de)充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流從1.8A提高到3A以(yi)上(shang)，用(yong)約4h的(de)(de)(de)時間對(dui)電(dian)(dian)(dian)池(chi)進(jin)(jin)行常規性(xing)充(chong)電(dian)(dian)(dian)，留出4h以(yi)上(shang)時間對(dui)電(dian)(dian)(dian)池(chi)進(jin)(jin)行修補(bu)性(xing)充(chong)電(dian)(dian)(dian)；二是(shi)給充(chong)電(dian)(dian)(dian)器(qi)增(zeng)加對(dui)電(dian)(dian)(dian)池(chi)進(jin)(jin)行修補(bu)性(xing)充(chong)電(dian)(dian)(dian)的(de)(de)(de)功能(neng)。

　　關于充電(dian)的波形和頻率

　　充(chong)電器賴以對電池(chi)產生影(ying)響的是(shi)充(chong)電電壓、電流(liu)及其波形和(he)頻(pin)率(lv)，其中，充(chong)電電壓主(zhu)要與電池(chi)充(chong)得滿不滿有(you)關，充(chong)電電流(liu)主(zhu)要與充(chong)電充(chong)得快不快有(you)關，而充(chong)電的波形和(he)頻(pin)率(lv)則主(zhu)要與充(chong)電充(chong)得好好不好有(you)關，這里(li)的“好不好”指得是(shi)電池(chi)的容量和(he)壽(shou)命。實(shi)踐證明，以上三者雖(sui)各(ge)有(you)側(ce)重，但其關系是(shi)相輔相成(cheng)、不可忽略的。

　　充(chong)(chong)電(dian)器(qi)屬(shu)于(yu)電(dian)源(yuan)技術領域，在充(chong)(chong)電(dian)過程中強(qiang)調波形和(he)頻(pin)率(lv)的作(zuo)用(yong)(yong)是開(kai)(kai)關電(dian)源(yuan)出現以后的事(shi)，而三段式(shi)(shi)充(chong)(chong)電(dian)模(mo)(mo)式(shi)(shi)出現在線性電(dian)源(yuan)時期，因此，三段式(shi)(shi)充(chong)(chong)電(dian)模(mo)(mo)式(shi)(shi)偏重于(yu)充(chong)(chong)電(dian)電(dian)壓和(he)電(dian)流(liu)，缺(que)少(shao)充(chong)(chong)電(dian)波形和(he)頻(pin)率(lv)方面的內容是情有可原的。現在，EB配置(zhi)的充(chong)(chong)電(dian)器(qi)全都是用(yong)(yong)開(kai)(kai)關電(dian)源(yuan)技術設計的，但卻仍采用(yong)(yong)三段式(shi)(shi)充(chong)(chong)電(dian)模(mo)(mo)式(shi)(shi)，這(zhe)顯(xian)然是不相宜的，據我們調查和(he)檢測(ce)，目前(qian)的EB充(chong)(chong)電(dian)器(qi)還不同程度地存在以下問題：

　　（1）輸出紋波太小。有(you)的(de)竟只有(you)50mV，顯(xian)然這(zhe)是(shi)將充電器當成穩(wen)壓(ya)電源來做了，也許這(zhe)種紋波可(ke)以用來給鋰離子電池充電，但對于36V鉛酸蓄電池來說，充電脈沖的(de)幅值應以1-2V為(wei)好。

　　（2）輸(shu)出(chu)連(lian)續三(san)角波(bo)(bo)。這通(tong)(tong)常(chang)是(shi)正(zheng)激(ji)式(shi)(shi)開(kai)關電(dian)(dian)源(yuan)充(chong)電(dian)(dian)器(qi)才有的(de)(de)波(bo)(bo)形，由于極(ji)化(hua)現象的(de)(de)存(cun)在，蓄電(dian)(dian)池忌諱用直流充(chong)電(dian)(dian)，包括連(lian)續三(san)角波(bo)(bo)。常(chang)規性充(chong)電(dian)(dian)的(de)(de)最好波(bo)(bo)形是(shi)單端反激(ji)式(shi)(shi)開(kai)關電(dian)(dian)源(yuan)通(tong)(tong)常(chang)所輸(shu)出(chu)的(de)(de)下降型脈沖(chong)，尤(you)其(qi)是(shi)緊接脈沖(chong)之后存(cun)在的(de)(de)一段休止時(shi)間，還可以消除鉛酸蓄電(dian)(dian)池因(yin)充(chong)電(dian)(dian)而產(chan)生(sheng)的(de)(de)電(dian)(dian)化(hua)學極(ji)化(hua)；比較而言，正(zheng)激(ji)式(shi)(shi)開(kai)關電(dian)(dian)源(yuan)充(chong)電(dian)(dian)器(qi)的(de)(de)溫升雖然(ran)可以做得低一些，但其(qi)輸(shu)出(chu)波(bo)(bo)形不如(ru)反激(ji)式(shi)(shi)電(dian)(dian)源(yuan)，不過(guo)這可以通(tong)(tong)過(guo)調(diao)整其(qi)輸(shu)出(chu)三(san)角波(bo)(bo)的(de)(de)占空比來加(jia)以彌補(bu)。

　　（3）在充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器與(yu)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)之(zhi)間串聯有一二極管。其目(mu)的(de)可(ke)能是(shi)(shi)為了防止電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)通過(guo)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器放(fang)電(dian)(dian)(dian)(dian)(dian)，但這樣做是(shi)(shi)錯誤的(de)。充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)就是(shi)(shi)需要又充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)又放(fang)，邊充(chong)(chong)邊放(fang)，充(chong)(chong)多放(fang)少，哪怕放(fang)電(dian)(dian)(dian)(dian)(dian)只有充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)的(de)百(bai)分(fen)之(zhi)一，也(ye)將會(hui)對(dui)抑制電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)氣(qi)化(hua)和(he)抬高氣(qi)化(hua)電(dian)(dian)(dian)(dian)(dian)壓等產生(sheng)不可(ke)替(ti)代的(de)作用。應該認(ren)識到，如(ru)能在每(mei)一常規性充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)周期留(liu)出(chu)幾微(wei)秒和(he)在修補性充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)周期留(liu)出(chu)幾秒鐘(zhong)用來放(fang)電(dian)(dian)(dian)(dian)(dian)，對(dui)消除(chu)鉛酸蓄電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)在充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)時產生(sheng)的(de)電(dian)(dian)(dian)(dian)(dian)化(hua)學極化(hua)和(he)濃差極化(hua)，從而(er)增加和(he)延(yan)長(chang)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)容量和(he)壽命(ming)將會(hui)有決定性意義(yi)。

（4）充(chong)(chong)(chong)電頻率單調。一(yi)個優秀的(de)充(chong)(chong)(chong)電器(qi)必須具(ju)有(you)多(duo)(duo)種充(chong)(chong)(chong)電模式(shi)：脈沖充(chong)(chong)(chong)電、負脈沖激活、變頻充(chong)(chong)(chong)電等模式(shi)，只(zhi)有(you)具(ju)備這(zhe)些技(ji)術的(de)充(chong)(chong)(chong)電器(qi)才能有(you)效地(di)(di)去(qu)除電解液濃度極(ji)(ji)差、板柵硫酸(suan)鹽化和(he)極(ji)(ji)化現象。脈沖充(chong)(chong)(chong)電、高頻充(chong)(chong)(chong)電以及變頻充(chong)(chong)(chong)電等充(chong)(chong)(chong)電技(ji)術，正在被越來越多(duo)(duo)地(di)(di)應用在充(chong)(chong)(chong)電器(qi)上(shang)，可(ke)以預期(qi)，一(yi)種兼有(you)常規性充(chong)(chong)(chong)電功能和(he)修補性充(chong)(chong)(chong)電功能的(de)多(duo)(duo)功能充(chong)(chong)(chong)電器(qi)必將(jiang)替(ti)代功能單一(yi)的(de)三段式(shi)充(chong)(chong)(chong)電器(qi)而成為EB的(de)主流。

　　一種實用(yong)的(de)EB多功能(neng)充電(dian)器的(de)充電(dian)模式和(he)參(can)數

　　如(ru)將(jiang)凡包含常規(gui)性(xing)充電(dian)(dian)(dian)(dian)(dian)功(gong)(gong)能(neng)和修補性(xing)充電(dian)(dian)(dian)(dian)(dian)功(gong)(gong)能(neng)的(de)(de)充電(dian)(dian)(dian)(dian)(dian)器統稱為多(duo)功(gong)(gong)能(neng)充電(dian)(dian)(dian)(dian)(dian)器，那么(me)根據以(yi)(yi)兩種充電(dian)(dian)(dian)(dian)(dian)功(gong)(gong)能(neng)結合(he)方式(shi)(shi)的(de)(de)不(bu)同，可以(yi)(yi)設計出多(duo)種模式(shi)(shi)的(de)(de)多(duo)功(gong)(gong)能(neng)充電(dian)(dian)(dian)(dian)(dian)器，但從EB的(de)(de)適用(yong)(yong)角度考慮，還是將(jiang)以(yi)(yi)上(shang)兩種充電(dian)(dian)(dian)(dian)(dian)功(gong)(gong)能(neng)分(fen)開來設計好，即(ji)將(jiang)有限(xian)的(de)(de)充電(dian)(dian)(dian)(dian)(dian)時(shi)間(jian)劃分(fen)為兩個充電(dian)(dian)(dian)(dian)(dian)時(shi)間(jian)段(duan)，前段(duan)時(shi)間(jian)用(yong)(yong)來完成常規(gui)性(xing)充電(dian)(dian)(dian)(dian)(dian)，后段(duan)時(shi)間(jian)用(yong)(yong)來進行修補性(xing)充電(dian)(dian)(dian)(dian)(dian)。以(yi)(yi)下仍以(yi)(yi)36V 12Ah鉛酸蓄(xu)電(dian)(dian)(dian)(dian)(dian)池組為例(li)，介(jie)紹一種實(shi)用(yong)(yong)的(de)(de)多(duo)功(gong)(gong)能(neng)充電(dian)(dian)(dian)(dian)(dian)器的(de)(de)充電(dian)(dian)(dian)(dian)(dian)模式(shi)(shi)和參數。

　　4.1常規(gui)性充(chong)電階(jie)段(duan)

　　（1）電源類型：單端反激式開關電源；

　　（2）滿輸出充電頻率：25kHz，即充電電源3A時的電源工作頻率；

　　（3）充電波形：下降型三角脈沖；

　　（4）脈沖(chong)幅度：約(yue)1.6V；

　　（5）脈沖最大寬度：約25μs；

　　（6）充(chong)電休止(zhi)時(shi)間(jian)：約15μs；

　　（7）放(fang)電電流：約50mA；

　　（8）充電平均電流：3A；

　　（9）充電(dian)峰值電(dian)流：約10A；

　　（10）充電(dian)時間：約4h，即充電(dian)4h后，電(dian)池(chi)電(dian)壓(ya)應上(shang)升到(dao)43.2V（常溫），容量已達75%以上(shang)；

　　（11）減流(liu)轉(zhuan)折(zhe)電(dian)壓：常溫下43.2V，該電(dian)壓為“氣化點電(dian)壓”，即(ji)在用(yong)直流(liu)充電(dian)的情況(kuang)下，此時(shi)鉛(qian)酸(suan)電(dian)池的電(dian)解(jie)液已(yi)開始大量氣化。以下轉(zhuan)入修補(bu)性充電(dian)階段。

　　4.2修補性充電階段

　　（1）線(xian)性減流(liu)(liu)及范圍：電(dian)(dian)(dian)池電(dian)(dian)(dian)壓上升到43.2V（常溫）時，充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)開始減小，減小的速率呈線(xian)性，平(ping)均(jun)充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)從3A最終減為不小于0.3A，或峰值充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)從約(yue)10A減為1A；

　　（2）充(chong)(chong)電(dian)(dian)頻(pin)率(lv)變(bian)(bian)化范圍：線(xian)性減(jian)流(liu)時，隨著(zhu)充(chong)(chong)電(dian)(dian)電(dian)(dian)流(liu)的(de)減(jian)小(xiao)，充(chong)(chong)電(dian)(dian)頻(pin)率(lv)開始上升，其變(bian)(bian)化范圍為25-100kHz；

　　（3）充(chong)(chong)(chong)電(dian)終止電(dian)壓(ya)：該電(dian)壓(ya)相(xiang)當(dang)于“氣化點電(dian)壓(ya)”加約1.2V，當(dang)電(dian)池電(dian)壓(ya)上升至(zhi)該電(dian)壓(ya)時(shi)，充(chong)(chong)(chong)電(dian)器終止充(chong)(chong)(chong)電(dian)；

　　（4）重起(qi)動電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)：終(zhong)止(zhi)充(chong)電(dian)(dian)(dian)(dian)后，電(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)下降(jiang)，當降(jiang)至重起(qi)動電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)時，充(chong)電(dian)(dian)(dian)(dian)器將再(zai)次(ci)起(qi)動將電(dian)(dian)(dian)(dian)池充(chong)到充(chong)電(dian)(dian)(dian)(dian)終(zhong)止(zhi)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)，而后充(chong)電(dian)(dian)(dian)(dian)終(zhong)止(zhi)，電(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)再(zai)次(ci)下降(jiang)，充(chong)電(dian)(dian)(dian)(dian)將循環(huan)反重地進行下去(qu)；

　　（5）充電(dian)終(zhong)止時(shi)(shi)間(jian)：終(zhong)止充電(dian)后，電(dian)池電(dian)壓下降的時(shi)(shi)間(jian)起先較快，約幾秒鐘，隨著時(shi)(shi)間(jian)推移(yi)，終(zhong)止充電(dian)的時(shi)(shi)間(jian)會越來越長(chang)，可達幾分鐘以上；

　　（6）修補性(xing)充電的延(yan)續時間(jian)：4h以上不限

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