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(shu)于傳統(tong)的(de)(de)三段(duan)(duan)(duan)式(shi)充(chong)電(dian)(dian)器，三段(duan)(duan)(duan)式(shi)充(chong)電(dian)(dian)器的(de)(de)充(chong)電(dian)(dian)模式(shi)是將(jiang)(jiang)(jiang)充(chong)電(dian)(dian)過程分(fen)為恒(heng)(heng)流(liu)、恒(heng)(heng)壓、浮充(chong)三個(ge)充(chong)電(dian)(dian)階段(duan)(duan)(duan)，以(yi)我(wo)國EB采用較多的(de)(de)36V12Ah鉛酸(suan)蓄電(dian)(dian)池組為例，第一階段(duan)(duan)(duan)以(yi)1.8A的(de)(de)恒(heng)(heng)定電(dian)(dian)流(liu)將(jiang)(jiang)(jiang)電(dian)(dian)池充(chong)到約44.4V；第二階段(duan)(duan)(duan)將(jiang)(jiang)(jiang)充(chong)電(dian)(dian)電(dian)(dian)流(liu)減(jian)小至約0.3A，再次將(jiang)(jiang)(jiang)電(dian)(dian)池電(dian)(dian)壓充(chong)到44.4V；第三階段(duan)(duan)(duan)將(jiang)(jiang)(jiang)電(dian)(dian)壓降(jiang)至約41.4V，電(dian)(dian)流(liu)減(jian)至約50MA對(dui)電(dian)(dian)池進行浮充(chong)。

　　從幾年來的使用情況看，三段式充電器暴露了(le)一些(xie)問(wen)題。以(yi)下仍以(yi)36V12Ah鉛酸蓄電(dian)池組為例(li)，談談三(san)段(duan)式充電(dian)器的缺陷和解(jie)決方案。

　　三段式充電(dian)(dian)器忽略了電(dian)(dian)池(chi)的負溫(wen)度特性(xing)

　　三(san)段式充(chong)電器(qi)充(chong)電參數的(de)(de)設定除(chu)受所配(pei)電池單(dan)體極(ji)板面(mian)積大小、電極(ji)特性、電解液密(mi)度(du)等因素影(ying)響外，還受蓄電池的(de)(de)環(huan)境溫度(du)的(de)(de)影(ying)響。

　　雖(sui)然一直(zhi)以(yi)來(lai)，人(ren)們都明白電(dian)化學的(de)溫度(du)效應(ying)(ying)是(shi)不能(neng)回避的(de)，但卻在(zai)充電(dian)器問(wen)題(ti)上忽(hu)略(lve)了(le)。原(yuan)因可(ke)以(yi)有很多，但特別應(ying)(ying)在(zai)此(ci)指出的(de)是(shi)：過去人(ren)們對蓄電(dian)池容量(liang)、壽(shou)命與溫度(du)之間(jian)關系的(de)感觸和認識從來(lai)沒有象今天這樣直(zhi)接(jie)和具體，須知，這是(shi)千萬個EB用(yong)戶參與了(le)“實驗”的(de)結果。

　　在我國(guo)幾乎所有的地區，使用無(wu)溫度(du)(du)補(bu)償的充(chong)電(dian)器，都會(hui)對(dui)電(dian)池(chi)造成(cheng)損害。夏季(ji)過(guo)充(chong)，冬季(ji)欠充(chong)，過(guo)充(chong)和欠充(chong)容易造成(cheng)電(dian)池(chi)失(shi)水(shui)和硫(liu)酸(suan)(suan)鹽(yan)化(hua)，電(dian)池(chi)失(shi)水(shui)后，硫(liu)酸(suan)(suan)濃度(du)(du)提(ti)高，加劇了板極腐蝕，就更容易產生硫(liu)酸(suan)(suan)鹽(yan)化(hua)，硫(liu)酸(suan)(suan)鹽(yan)化(hua)的電(dian)池(chi)表現為更容易失(shi)水(shui)。這是一種(zhong)連鎖反應(ying)。鉛酸(suan)(suan)電(dian)池(chi)硫(liu)酸(suan)(suan)鹽(yan)化(hua)是影響EB續(xu)駛里程和電(dian)池(chi)壽命的重要因素(su)。

　　無溫度補嘗的充電(dian)器究竟對電(dian)池(chi)(chi)的損害(hai)有多大(da)，目前(qian)還(huan)缺少(shao)實驗(yan)數據，對蓄電(dian)池(chi)(chi)進行(xing)定量分(fen)析要比定性分(fen)析復雜困難得多，但(dan)以下的數據可以參考：EB標準規(gui)定，鉛(qian)酸蓄電(dian)池(chi)(chi)的循環(huan)次(ci)數不(bu)得不(bu)少(shao)于350次(ci)，但(dan)實際上(shang)有相當多的電(dian)池(chi)(chi)使(shi)用時間不(bu)到8個月，即循還(huan)次(ci)數不(bu)足(zu)240次(ci)。

　　充(chong)電(dian)器增加溫(wen)(wen)度(du)補償功能并不(bu)困難，如只要將原基準(zhun)電(dian)壓(ya)改為具有(you)負溫(wen)(wen)度(du)系數特(te)性的基準(zhun)電(dian)壓(ya)，一般就可以了。

　　三段式充(chong)電模(mo)式缺少修(xiu)補性充(chong)電環節

　　三(san)(san)段式(shi)充(chong)(chong)電(dian)(dian)模式(shi)的(de)(de)恒流(liu)――恒壓――浮充(chong)(chong)三(san)(san)個(ge)充(chong)(chong)電(dian)(dian)階段，都是圍繞怎樣(yang)充(chong)(chong)滿電(dian)(dian)池(chi)來(lai)設計的(de)(de)，因(yin)此，這三(san)(san)個(ge)充(chong)(chong)電(dian)(dian)階段占用了全部(bu)充(chong)(chong)電(dian)(dian)時(shi)間，如36V12Ah電(dian)(dian)池(chi)組(zu)的(de)(de)充(chong)(chong)電(dian)(dian)電(dian)(dian)流(liu)通常(chang)被設定為18A，有公(gong)式(shi)：12(安時(shi)）×1.2（效率(lv)）÷8（小時(shi)）=1.8A。恰好能在標準規定的(de)(de)8h內將電(dian)(dian)池(chi)充(chong)(chong)滿，設計時(shi)就沒打算(suan)留(liu)出修補(bu)電(dian)(dian)池(chi)的(de)(de)時(shi)間，更何況三(san)(san)段式(shi)充(chong)(chong)電(dian)(dian)器一般也不具備修補(bu)電(dian)(dian)池(chi)的(de)(de)功能。

　　產業界向來有(you)(you)人(ren)認為(wei)：我(wo)國的EB以(yi)采用鉛酸蓄(xu)電(dian)(dian)(dian)池(chi)(chi)為(wei)主，并且采取(qu)的是(shi)(shi)全(quan)動力模式，如電(dian)(dian)(dian)池(chi)(chi)長期不能(neng)(neng)(neng)達標，我(wo)國的EB產業將可能(neng)(neng)(neng)有(you)(you)再次夭折的危險。但(dan)技術(shu)界對此(ci)問題的認識是(shi)(shi)：要想鉛酸蓄(xu)電(dian)(dian)(dian)池(chi)(chi)達標，除有(you)(you)待于電(dian)(dian)(dian)池(chi)(chi)本(ben)身的技術(shu)進步外，采用充電(dian)(dian)(dian)與修(xiu)補功(gong)能(neng)(neng)(neng)兼備的多功(gong)能(neng)(neng)(neng)充電(dian)(dian)(dian)器是(shi)(shi)解(jie)決問題的有(you)(you)效途徑(jing)。因此(ci)，我(wo)們建議立即從(cong)(cong)以(yi)下兩方面(mian)入手對EB充電(dian)(dian)(dian)器進行技術(shu)改造。一是(shi)(shi)將36V12Ah電(dian)(dian)(dian)池(chi)(chi)組(zu)的充電(dian)(dian)(dian)電(dian)(dian)(dian)流從(cong)(cong)1.8A提高(gao)到3A以(yi)上，用約4h的時間對電(dian)(dian)(dian)池(chi)(chi)進行常規性充電(dian)(dian)(dian)，留出4h以(yi)上時間對電(dian)(dian)(dian)池(chi)(chi)進行修(xiu)補性充電(dian)(dian)(dian)；二是(shi)(shi)給(gei)充電(dian)(dian)(dian)器增加對電(dian)(dian)(dian)池(chi)(chi)進行修(xiu)補性充電(dian)(dian)(dian)的功(gong)能(neng)(neng)(neng)。

　　關于充(chong)電的(de)波形和頻率(lv)

　　充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)賴以(yi)對電(dian)(dian)(dian)(dian)池(chi)產生影響的是充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓(ya)、電(dian)(dian)(dian)(dian)流(liu)及其(qi)波(bo)形和(he)頻率，其(qi)中，充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓(ya)主要(yao)(yao)與(yu)(yu)電(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)得滿不(bu)滿有(you)(you)關，充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)主要(yao)(yao)與(yu)(yu)充(chong)(chong)電(dian)(dian)(dian)(dian)充(chong)(chong)得快不(bu)快有(you)(you)關，而充(chong)(chong)電(dian)(dian)(dian)(dian)的波(bo)形和(he)頻率則主要(yao)(yao)與(yu)(yu)充(chong)(chong)電(dian)(dian)(dian)(dian)充(chong)(chong)得好好不(bu)好有(you)(you)關，這(zhe)里的“好不(bu)好”指得是電(dian)(dian)(dian)(dian)池(chi)的容量和(he)壽命。實踐(jian)證明，以(yi)上三(san)者雖(sui)各有(you)(you)側重，但其(qi)關系是相輔相成(cheng)、不(bu)可忽略的。

　　充(chong)電器屬于(yu)電源(yuan)技術(shu)領域，在(zai)充(chong)電過程中強(qiang)調波形(xing)(xing)和(he)頻率的(de)(de)作用(yong)是開關電源(yuan)出現(xian)以后的(de)(de)事，而三段(duan)(duan)式充(chong)電模式出現(xian)在(zai)線性電源(yuan)時期，因(yin)此，三段(duan)(duan)式充(chong)電模式偏重于(yu)充(chong)電電壓和(he)電流，缺少充(chong)電波形(xing)(xing)和(he)頻率方面的(de)(de)內容(rong)是情(qing)有可原的(de)(de)。現(xian)在(zai)，EB配(pei)置的(de)(de)充(chong)電器全都是用(yong)開關電源(yuan)技術(shu)設計的(de)(de)，但(dan)卻仍采(cai)用(yong)三段(duan)(duan)式充(chong)電模式，這顯然是不(bu)相宜的(de)(de)，據我們(men)調查和(he)檢測，目前的(de)(de)EB充(chong)電器還不(bu)同程度地存在(zai)以下問(wen)題：

　　（1）輸出紋波太小。有的竟只有50mV，顯然這是將充(chong)(chong)電(dian)(dian)(dian)器當成穩壓電(dian)(dian)(dian)源來做了(le)，也許這種(zhong)紋波可以(yi)用來給鋰離子電(dian)(dian)(dian)池充(chong)(chong)電(dian)(dian)(dian)，但對于36V鉛酸蓄電(dian)(dian)(dian)池來說，充(chong)(chong)電(dian)(dian)(dian)脈(mo)沖的幅值應以(yi)1-2V為好。

　　（2）輸(shu)(shu)出(chu)連(lian)續三角(jiao)波(bo)(bo)(bo)。這通(tong)(tong)常(chang)是正(zheng)激(ji)式(shi)開(kai)關(guan)電(dian)源充(chong)電(dian)器(qi)才有(you)的(de)(de)波(bo)(bo)(bo)形，由于極(ji)化現象的(de)(de)存在，蓄(xu)電(dian)池(chi)忌諱用直流充(chong)電(dian)，包括連(lian)續三角(jiao)波(bo)(bo)(bo)。常(chang)規(gui)性充(chong)電(dian)的(de)(de)最好波(bo)(bo)(bo)形是單端反(fan)激(ji)式(shi)開(kai)關(guan)電(dian)源通(tong)(tong)常(chang)所輸(shu)(shu)出(chu)的(de)(de)下降型(xing)脈沖，尤其(qi)是緊接脈沖之后存在的(de)(de)一段休止(zhi)時(shi)間，還(huan)可(ke)(ke)以消除鉛(qian)酸蓄(xu)電(dian)池(chi)因充(chong)電(dian)而(er)產生的(de)(de)電(dian)化學極(ji)化；比較而(er)言，正(zheng)激(ji)式(shi)開(kai)關(guan)電(dian)源充(chong)電(dian)器(qi)的(de)(de)溫升雖然可(ke)(ke)以做(zuo)得低(di)一些，但其(qi)輸(shu)(shu)出(chu)波(bo)(bo)(bo)形不(bu)如反(fan)激(ji)式(shi)電(dian)源，不(bu)過這可(ke)(ke)以通(tong)(tong)過調整其(qi)輸(shu)(shu)出(chu)三角(jiao)波(bo)(bo)(bo)的(de)(de)占空比來加以彌補(bu)。

　　（3）在(zai)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)與電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)之間串聯有一二(er)極(ji)管(guan)。其目的(de)(de)(de)(de)可能(neng)是為(wei)了(le)防止電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)通(tong)過充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)放電(dian)(dian)(dian)(dian)(dian)，但(dan)這(zhe)樣做是錯誤(wu)的(de)(de)(de)(de)。充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)就是需要又(you)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)又(you)放，邊(bian)充(chong)(chong)(chong)(chong)邊(bian)放，充(chong)(chong)(chong)(chong)多(duo)放少，哪怕放電(dian)(dian)(dian)(dian)(dian)只有充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)(de)百分(fen)之一，也將(jiang)會(hui)對抑制(zhi)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)氣化(hua)和抬(tai)高氣化(hua)電(dian)(dian)(dian)(dian)(dian)壓等產生不可替代的(de)(de)(de)(de)作(zuo)用。應該認識(shi)到，如能(neng)在(zai)每一常規(gui)性(xing)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)周期(qi)留出幾(ji)微秒和在(zai)修(xiu)補性(xing)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)周期(qi)留出幾(ji)秒鐘用來放電(dian)(dian)(dian)(dian)(dian)，對消除鉛酸蓄電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)在(zai)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)時產生的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)化(hua)學極(ji)化(hua)和濃(nong)差極(ji)化(hua)，從而增加(jia)和延長電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)(de)(de)容量和壽命將(jiang)會(hui)有決定性(xing)意義。

（4）充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)頻(pin)率單調。一個優秀的充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器必(bi)須具有多(duo)種(zhong)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)模(mo)式：脈(mo)(mo)沖(chong)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)、負脈(mo)(mo)沖(chong)激活(huo)、變頻(pin)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)等模(mo)式，只有具備這些技術(shu)的充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器才能(neng)有效地去除電(dian)(dian)(dian)(dian)解(jie)液濃(nong)度極差、板柵硫(liu)酸鹽化和極化現象。脈(mo)(mo)沖(chong)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)、高頻(pin)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)以及(ji)變頻(pin)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)等充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)技術(shu)，正在(zai)被(bei)越來越多(duo)地應用在(zai)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器上，可(ke)以預期，一種(zhong)兼有常規性充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)功(gong)能(neng)和修補性充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)功(gong)能(neng)的多(duo)功(gong)能(neng)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器必(bi)將替代功(gong)能(neng)單一的三段式充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器而(er)成為EB的主(zhu)流。

　　一(yi)種實用的(de)EB多功能充電器的(de)充電模(mo)式和參數

　　如將(jiang)凡包含常(chang)規(gui)性(xing)(xing)充(chong)(chong)電功能(neng)和修(xiu)補性(xing)(xing)充(chong)(chong)電功能(neng)的充(chong)(chong)電器(qi)(qi)統稱(cheng)為(wei)多(duo)功能(neng)充(chong)(chong)電器(qi)(qi)，那么根據以(yi)(yi)兩種(zhong)(zhong)充(chong)(chong)電功能(neng)結合方式的不同，可以(yi)(yi)設計出(chu)多(duo)種(zhong)(zhong)模式的多(duo)功能(neng)充(chong)(chong)電器(qi)(qi)，但從EB的適用角度考慮，還(huan)是將(jiang)以(yi)(yi)上兩種(zhong)(zhong)充(chong)(chong)電功能(neng)分開來(lai)設計好，即將(jiang)有限的充(chong)(chong)電時間(jian)(jian)劃(hua)分為(wei)兩個充(chong)(chong)電時間(jian)(jian)段，前段時間(jian)(jian)用來(lai)完成常(chang)規(gui)性(xing)(xing)充(chong)(chong)電，后段時間(jian)(jian)用來(lai)進行修(xiu)補性(xing)(xing)充(chong)(chong)電。以(yi)(yi)下仍(reng)以(yi)(yi)36V 12Ah鉛(qian)酸蓄(xu)電池組為(wei)例，介(jie)紹(shao)一種(zhong)(zhong)實用的多(duo)功能(neng)充(chong)(chong)電器(qi)(qi)的充(chong)(chong)電模式和參數(shu)。

　　4.1常規性充電階段

　　（1）電源類型(xing)：單(dan)端反(fan)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(zuo)頻率；

　　（3）充電(dian)波(bo)形：下降型三(san)角脈沖；

　　（4）脈沖幅度：約1.6V；

　　（5）脈(mo)沖最大寬度：約25μs；

　　（6）充電休止時間：約15μs；

　　（7）放電電流(liu)：約(yue)50mA；

　　（8）充電平均電流：3A；

　　（9）充電峰值電流：約(yue)10A；

　　（10）充(chong)電時間：約4h，即充(chong)電4h后，電池電壓應上升到(dao)43.2V（常溫），容量已(yi)達75%以(yi)上；

　　（11）減(jian)流轉(zhuan)折(zhe)電(dian)壓：常溫下43.2V，該電(dian)壓為(wei)“氣化點電(dian)壓”，即在(zai)用直流充(chong)電(dian)的情(qing)況下，此時(shi)鉛酸電(dian)池的電(dian)解液已(yi)開始大量氣化。以(yi)下轉(zhuan)入修(xiu)補性充(chong)電(dian)階段(duan)。

　　4.2修(xiu)補性(xing)充電階段

　　（1）線性減(jian)(jian)流及范圍(wei)：電(dian)(dian)池電(dian)(dian)壓上升到43.2V（常溫）時，充電(dian)(dian)電(dian)(dian)流開(kai)始減(jian)(jian)小(xiao)，減(jian)(jian)小(xiao)的速率呈線性，平均充電(dian)(dian)電(dian)(dian)流從3A最終減(jian)(jian)為(wei)不小(xiao)于(yu)0.3A，或峰值充電(dian)(dian)電(dian)(dian)流從約10A減(jian)(jian)為(wei)1A；

　　（2）充(chong)電(dian)頻率(lv)變化范(fan)圍(wei)：線性減(jian)流(liu)(liu)時，隨著充(chong)電(dian)電(dian)流(liu)(liu)的(de)減(jian)小，充(chong)電(dian)頻率(lv)開始上(shang)升，其變化范(fan)圍(wei)為25-100kHz；

　　（3）充(chong)電(dian)(dian)(dian)終(zhong)止電(dian)(dian)(dian)壓：該電(dian)(dian)(dian)壓相當于(yu)“氣(qi)化點電(dian)(dian)(dian)壓”加約1.2V，當電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓上升至(zhi)該電(dian)(dian)(dian)壓時，充(chong)電(dian)(dian)(dian)器(qi)終(zhong)止充(chong)電(dian)(dian)(dian)；

　　（4）重(zhong)起動(dong)電(dian)壓(ya)：終止(zhi)充電(dian)后，電(dian)池電(dian)壓(ya)下(xia)降，當降至(zhi)重(zhong)起動(dong)電(dian)壓(ya)時，充電(dian)器將再次起動(dong)將電(dian)池充到充電(dian)終止(zhi)電(dian)壓(ya)，而后充電(dian)終止(zhi)，電(dian)池電(dian)壓(ya)再次下(xia)降，充電(dian)將循(xun)環反重(zhong)地進行下(xia)去(qu)；

　　（5）充(chong)電終(zhong)止時(shi)間：終(zhong)止充(chong)電后，電池(chi)電壓(ya)下降(jiang)的(de)時(shi)間起先較快(kuai)，約幾秒鐘(zhong)，隨(sui)著時(shi)間推移(yi)，終(zhong)止充(chong)電的(de)時(shi)間會越(yue)來(lai)越(yue)長，可(ke)達幾分(fen)鐘(zhong)以上；

　　（6）修補性充電的延續時(shi)間(jian)：4h以上不限

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