鉛酸蓄電(dian)池(chi)由于其成(cheng)本低、容量大、安(an)全可靠等特點，在通信、電(dian)動汽車、軍(jun)事、航(hang)空航(hang)天等各個領(ling)域都有廣(guang)泛的應(ying)用。電(dian)池(chi)的性能(neng)好(hao)壞(huai)、使用壽(shou)命(ming)的長(chang)短直(zhi)接影(ying)響到電(dian)子產(chan)品(pin)的使用壽(shou)命(ming)和使用安(an)全；而充電(dian)器的好(hao)壞(huai)又直(zhi)接影(ying)響到電(dian)池(chi)的使用壽(shou)命(ming)。因此研究(jiu)低成(cheng)本又有智(zhi)能(neng)管理功能(neng)的充電(dian)器是有實際(ji)應(ying)用價值的課題。

　　1 目前智能(neng)充電器的幾種結構［1］

　　1.1 基于(yu)專用芯(xin)片的管理(li)系(xi)統

　　現(xian)(xian)在，UNITRODE 公(gong)司已開發出系列電(dian)(dian)(dian)池管(guan)理(li)專用芯片(pian)。因為電(dian)(dian)(dian)池管(guan)理(li)中采用最多(duo)的(de)就是(shi)控(kong)制(zhi)充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)壓及充(chong)放電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)，電(dian)(dian)(dian)池管(guan)理(li)芯片(pian)正是(shi)抓住(zhu)了(le)這一點，為VRLA 電(dian)(dian)(dian)池研(yan)制(zhi)了(le)具有四(si)狀態管(guan)理(li)的(de)專用控(kong)制(zhi)芯片(pian)，可(ke)以(yi)智能地實現(xian)(xian)帶溫(wen)度補償(chang)的(de)四(si)狀態管(guan)理(li)方案：涓流(liu)充(chong)電(dian)(dian)(dian)模(mo)式(shi)(shi)(shi)、大功率充(chong)電(dian)(dian)(dian)模(mo)式(shi)(shi)(shi)、過充(chong)電(dian)(dian)(dian)模(mo)式(shi)(shi)(shi)和浮充(chong)電(dian)(dian)(dian)模(mo)式(shi)(shi)(shi)。不(bu)同的(de)電(dian)(dian)(dian)池要有不(bu)同的(de)芯片(pian)控(kong)制(zhi)，因此，用專用芯片(pian)做管(guan)理(li)系統其靈活性較差，

　　1.2 基(ji)于監控測量(liang)的(de)蓄電(dian)池管理系統

　　在給電(dian)池(chi)(chi)充電(dian)的(de)過程中(zhong)，涉及到電(dian)池(chi)(chi)工作(zuo)電(dian)壓、工作(zuo)電(dian)流、溫度等參數，這些(xie)都是表征電(dian)池(chi)(chi)狀態的(de)重要參數。采用(yong)傳感器提(ti)取這些(xie)參數，然(ran)后再(zai)配合故障診斷(duan)、遙(yao)控遙(yao)測、自動報警和事故現(xian)場處理(li)(li)等功能(neng)，就可以組成一個電(dian)池(chi)(chi)管(guan)理(li)(li)系統。如圖1所示。

　　1.3 與電(dian)源(yuan)設備一起構(gou)成的(de)蓄電(dian)池充放(fang)電(dian)管理系(xi)統(tong)

　　在通訊、供電系統中，為了保證電網掉電時蓄電池組能及時補充電能，在規定時間內向負載供電，保證通信或電力合閘系統的正常運轉，通常是將電池組直接掛接在電源模塊輸出端。當電網正常工作時，電池組工作在浮充狀態，起到平滑濾波和保持容量（補充自放電的容量損失）的作用。一旦電網掉電，蓄電池組立即投入工作，當電網恢復，電源模塊立即對電池進行充電。如圖2 所示。

　　這(zhe)樣(yang)的一(yi)(yi)個(ge)系(xi)統(tong)由于(yu)和(he)(he)電(dian)(dian)源模(mo)(mo)塊(kuai)聯系(xi)起來，所(suo)以，可(ke)以從充放(fang)電(dian)(dian)過程上(shang)(shang)來優化(hua)電(dian)(dian)池(chi)(chi)工(gong)(gong)作狀態(tai)，電(dian)(dian)池(chi)(chi)充電(dian)(dian)成(cheng)為可(ke)控(kong)的過程，建立在這(zhe)樣(yang)一(yi)(yi)個(ge)系(xi)統(tong)上(shang)(shang)的監(jian)(jian)控(kong)單元應該具有第一(yi)(yi)種監(jian)(jian)控(kong)系(xi)統(tong)中所(suo)有功能(neng)，并且可(ke)以和(he)(he)電(dian)(dian)源模(mo)(mo)塊(kuai)直接“對話”，根據要(yao)求對電(dian)(dian)池(chi)(chi)進行管(guan)理，并且可(ke)以實時監(jian)(jian)控(kong)電(dian)(dian)池(chi)(chi)的放(fang)電(dian)(dian)狀態(tai)，對電(dian)(dian)池(chi)(chi)的工(gong)(gong)作進行優化(hua)［2］。因此(ci)，電(dian)(dian)池(chi)(chi)組的工(gong)(gong)作會更(geng)加可(ke)靠，可(ke)控(kong)性和(he)(he)智能(neng)化(hua)程度也會更(geng)高。但(dan)是這(zhe)樣(yang)一(yi)(yi)個(ge)系(xi)統(tong)存在的主要(yao)問題是：

　　（1）沒有解決電(dian)池(chi)組串聯運行過程中不均衡 現象的問題，這也(ye)是電(dian)池(chi)失效的重要(yao)原因之(zhi)一；

　　（2）一般只(zhi)完(wan)成了電(dian)池生(sheng)產廠家提(ti)供的充電(dian)曲線(xian)，對于電(dian)池在使用(yong)過程中(zhong)發生(sheng)的其它(ta)問題控制不夠全面，例如深(shen)度放電(dian)后(hou)的涓充問題等。

　　在(zai)將來，充電器的(de)發展方向是智(zhi)能(neng)化、數(shu)字化、集成(cheng)化。智(zhi)能(neng)化可以使電池的(de)管(guan)理做到全自(zi)動，無需人員監管(guan)，真正做到免維護。數(shu)字化和(he)集成(cheng)化可以減(jian)少(shao)管(guan)理系統(tong)的(de)體積和(he)重(zhong)量，減(jian)少(shao)系統(tong)的(de)復雜度。

　　2 目前幾種充電方式［3］

　　鉛酸蓄電(dian)池的充(chong)電(dian)方法目前(qian)主要有恒(heng)流、恒(heng)壓、恒(heng)壓限流、脈沖充(chong)電(dian)、Reflex充(chong)電(dian)法。

　　2.1 恒流充(chong)電

　　恒流(liu)(liu)充電(dian)方(fang)式是(shi)一種簡單(dan)的充電(dian)方(fang)法。但是(shi)，恒流(liu)(liu)充電(dian)有其局限性：對電(dian)池(chi)過(guo)充電(dian)就(jiu)會造成(cheng)電(dian)池(chi)壽命的縮短，而過(guo)小電(dian)流(liu)(liu)又會延長(chang)充電(dian)時間。

　　2.2 恒壓充電

　　恒壓(ya)充(chong)(chong)電(dian)(dian)(dian)用簡單的(de)控制方法很(hen)容易就(jiu)能(neng)實(shi)現。在充(chong)(chong)電(dian)(dian)(dian)的(de)初始階段(duan)，由于(yu)電(dian)(dian)(dian)池(chi)的(de)電(dian)(dian)(dian)壓(ya)很(hen)低而造成(cheng)充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流很(hen)大，這(zhe)對電(dian)(dian)(dian)池(chi)會(hui)造成(cheng)損害(hai)。當電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓(ya)達到一(yi)定值之后，電(dian)(dian)(dian)流就(jiu)會(hui)隨之減(jian)小(xiao)。這(zhe)種充(chong)(chong)電(dian)(dian)(dian)方法的(de)缺點就(jiu)是會(hui)造成(cheng)溫度上(shang)升和電(dian)(dian)(dian)池(chi)的(de)壽命(ming)減(jian)少(shao)，并且在開(kai)始時電(dian)(dian)(dian)流很(hen)大，而后來快充(chong)(chong)滿時電(dian)(dian)(dian)流又很(hen)小(xiao)，就(jiu)無法充(chong)(chong)分利用充(chong)(chong)電(dian)(dian)(dian)器的(de)容量。

　　2.3 恒壓限流法

　　恒(heng)壓(ya)限(xian)流(liu)法(fa)實際(ji)上是(shi)將恒(heng)壓(ya)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)和恒(heng)流(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)相結合，又(you)可稱為混(hun)合充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)法(fa)。在(zai)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)開始(shi)階段，由于(yu)電(dian)(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)過(guo)低(di)，為避免電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)過(guo)大(da)(da)而(er)損壞電(dian)(dian)(dian)(dian)(dian)(dian)池，就(jiu)采用恒(heng)流(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)法(fa)來限(xian)制(zhi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)。但電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)達到預定(ding)值時(shi)，進入恒(heng)壓(ya)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)方(fang)式(shi)(shi)。恒(heng)壓(ya)限(xian)流(liu)方(fang)式(shi)(shi)是(shi)大(da)(da)多數(shu)電(dian)(dian)(dian)(dian)(dian)(dian)池廠商推(tui)薦(jian)的(de)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)方(fang)式(shi)(shi)。由于(yu)蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)池充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)較低(di)，充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)后期電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)很(hen)小，因此(ci)電(dian)(dian)(dian)(dian)(dian)(dian)解液中產生的(de)氣泡很(hen)少，可以節省(sheng)電(dian)(dian)(dian)(dian)(dian)(dian)能、降(jiang)低(di)蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)池的(de)溫升，避免損壞電(dian)(dian)(dian)(dian)(dian)(dian)池的(de)極板。恒(heng)壓(ya)限(xian)流(liu)方(fang)式(shi)(shi)是(shi)一(yi)種很(hen)有效的(de)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)方(fang)式(shi)(shi)，加(jia)上過(guo)充(chong)(chong)判斷、浮充(chong)(chong)控制(zhi)、溫度補償等就(jiu)可以形成(cheng)一(yi)個簡(jian)單的(de)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)管理系(xi)統，蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)池可以在(zai)這個系(xi)統下(xia)更(geng)好地工作。

　　2.4 脈沖充電［4］

　　在(zai)充(chong)(chong)(chong)(chong)(chong)電(dian)過(guo)程中，只要(yao)(yao)充(chong)(chong)(chong)(chong)(chong)電(dian)電(dian)流(liu)不超過(guo)蓄(xu)電(dian)池(chi)可接(jie)受(shou)的電(dian)流(liu)，蓄(xu)電(dian)池(chi)內部就(jiu)不會(hui)產(chan)生大量(liang)的氣泡。蓄(xu)電(dian)池(chi)中產(chan)生的極化現象會(hui)阻礙(ai)充(chong)(chong)(chong)(chong)(chong)電(dian)，并且使出(chu)氣率和溫升顯著升高(gao)。因此，極化電(dian)壓是(shi)影響充(chong)(chong)(chong)(chong)(chong)電(dian)速(su)度的重要(yao)(yao)因素。用(yong)周期性(xing)的脈(mo)動電(dian)流(liu)給電(dian)池(chi)充(chong)(chong)(chong)(chong)(chong)電(dian)可以使電(dian)池(chi)有(you)時間恢復(fu)其原(yuan)來狀態，減小極化現象的影響，解決快速(su)充(chong)(chong)(chong)(chong)(chong)電(dian)面臨(lin)的難(nan)題。但是(shi)目(mu)前這種充(chong)(chong)(chong)(chong)(chong)電(dian)方式還在(zai)研究階段，對于采用(yong)多(duo)大的脈(mo)沖周期，占空比又是(shi)多(duo)少之(zhi)類的具(ju)體問題還沒有(you)一個(ge)定論(lun)。

　　2.5 ReflexTM充電(dian)方式

　　Reflex 充電方法是脈沖電流法的改進：一個周期是由一個正脈沖后加一個負脈沖，然后才是空閑時段。這樣就強制消除電池的極化現象，使得電池充電時可以更快而又不損害電池的使用壽命。這種充電方式與脈沖充電方式一樣，仍然處于研究階段。
.　3 數(shu)字(zi)式智能充電(dian)器的設計

　　3.1 系(xi)統結構和(he)充電方案的設(she)計

　　本文中設計(ji)的(de)系統是一個(ge)針(zhen)對12 V/（200～500Ah）的(de)鉛酸蓄電池智(zhi)能充電系統。采用半橋作為(wei)主(zhu)功率拓(tuo)撲，開關頻率取80kHz左右。

　　對于(yu)一個(ge)智(zhi)能管理系統(tong)，控(kong)制(zhi)模(mo)塊(kuai)無異于(yu)它(ta)的(de)(de)(de)大腦。充電器的(de)(de)(de)所有(you)動作(zuo)都(dou)是由它(ta)來決(jue)定和控(kong)制(zhi)的(de)(de)(de)，所以控(kong)制(zhi)模(mo)塊(kuai)的(de)(de)(de)選(xuan)(xuan)擇關系到整(zheng)個(ge)系統(tong)的(de)(de)(de)優(you)劣。由于(yu)系統(tong)需要多個(ge)A/D 轉換(huan)器，但不需要擴展存儲(chu)器也不需要通訊，根據以上(shang)特點(dian)我們(men)選(xuan)(xuan)擇了(le)MICROCHIP 公司的(de)(de)(de)PIC 系列PIC16C73 單片(pian)機。

　　圖3 所示為智能充電器的(de)系統框(kuang)圖。單片(pian)機是智能充(chong)電(dian)器的(de)核心部(bu)件(jian)，它根據電(dian)流、電(dian)壓采(cai)樣(yang)以(yi)及溫(wen)度(du)采(cai)樣(yang)做出溫(wen)度(du)補償后的(de)PWM波形輸出，經過(guo)驅動(dong)電(dian)路(lu)(lu)提供給(gei)功(gong)率電(dian)路(lu)(lu)，并且決(jue)定(ding)了(le)智能充(chong)電(dian)器的(de)工作(zuo)狀態，可以(yi)在必要的(de)情(qing)況下做出保(bao)護動(dong)作(zuo)。意外故障保(bao)護電(dian)路(lu)(lu)可以(yi)在單片(pian)機失效(xiao)的(de)情(qing)況下對電(dian)路(lu)(lu)進行強制保(bao)護，起(qi)到雙重(zhong)保(bao)險的(de)作(zuo)用(yong)。報警顯示部(bu)分用(yong)若干個LED表示系統的(de)運行狀態，簡單有效(xiao)。

　　充(chong)電(dian)(dian)(dian)方式采用恒壓(ya)限流(liu)(liu)法。恒壓(ya)限流(liu)(liu)充(chong)電(dian)(dian)(dian)模(mo)式分(fen)兩個(ge)階段(duan)(duan)，第一階段(duan)(duan)是恒流(liu)(liu)階段(duan)(duan)，即系(xi)統給(gei)定電(dian)(dian)(dian)流(liu)(liu)值(zhi)(zhi)，給(gei)電(dian)(dian)(dian)池(chi)以(yi)恒定電(dian)(dian)(dian)流(liu)(liu)充(chong)電(dian)(dian)(dian)，當電(dian)(dian)(dian)池(chi)的電(dian)(dian)(dian)壓(ya)達(da)到系(xi)統給(gei)定的轉化(hua)值(zhi)(zhi)，就(jiu)轉為第二階段(duan)(duan)―――恒壓(ya)階段(duan)(duan)。恒壓(ya)轉化(hua)值(zhi)(zhi)會(hui)影響充(chong)入電(dian)(dian)(dian)量的多少。

　　由圖4 可(ke)知，當恒壓轉化值（Vref）設置的(de)(de)較低時，充入的(de)(de)電(dian)量(liang)不足（圖中陰(yin)影部分就是少充入的(de)(de)容(rong)(rong)(rong)量(liang)），沒(mei)有充分利用電(dian)池(chi)的(de)(de)容(rong)(rong)(rong)量(liang)，長期工作，會引起電(dian)池(chi)容(rong)(rong)(rong)量(liang)丟失(shi)，這就要求把恒壓轉化值設高。但是恒壓值較高，容(rong)(rong)(rong)易在充電(dian)末期引起過充電(dian)，這同樣會導致電(dian)池(chi)容(rong)(rong)(rong)量(liang)丟失(shi)。

　　為了(le)解決這(zhe)個矛盾，系(xi)統引進(jin)了(le)第三個階(jie)段―――浮充(chong)階(jie)段，這(zhe)樣就可(ke)以把(ba)恒壓轉化值設置的比(bi)普通(tong)恒壓限流模(mo)式高，這(zhe)樣可(ke)以保證(zheng)充(chong)入(ru)(ru)足夠的電(dian)量，在充(chong)電(dian)末期轉入(ru)(ru)浮充(chong)階(jie)段，用稍低的電(dian)壓浮充(chong)充(chong)電(dian)，從而保證(zheng)不會過充(chong)電(dian)。

　　三階(jie)段充(chong)電(dian)(dian)方法保證了充(chong)電(dian)(dian)末期不過充(chong)，同時又能達到滿充(chong)的(de)目的(de)，是一種成本(ben)較低(di)的(de)通用蓄(xu)電(dian)(dian)池充(chong)電(dian)(dian)解決(jue)方案。

　　3.2 軟件系統的設(she)計

　　圖5 為系統軟件的程序流程圖。根(gen)據電池的端電壓決(jue)定充電器工作在(zai)何種充電狀(zhuang)態。

　　我們做(zuo)的是全數(shu)字化的改良型PI 調節(jie)環(huan)，由于(yu)PI 調節(jie)的積(ji)分(fen)環(huan)在前(qian)期對誤差進行積(ji)累(lei)，為了(le)不讓(rang)積(ji)累(lei)的誤差影響系統的穩定(ding)性(xing)，所以我們在誤差等(deng)于(yu)0 時(shi)，對原有積(ji)累(lei)的誤差清(qing)零。當(dang)誤差等(deng)于(yu)±1 時(shi)，只進行積(ji)分(fen)運算(suan)，減慢調整(zheng)速度，避免產(chan)生振蕩。

　　鉛酸(suan)蓄電池(chi)的(de)充電電壓需要(yao)根據(ju)環境溫度進行調整(zheng)，以(yi)－4 mV/℃的(de)補償系數來調整(zheng)。因(yin)此我(wo)們加入了(le)溫度補償的(de)功能。

　　4 實驗結果

　　圖6 為用電(dian)(dian)(dian)子(zi)負載模擬電(dian)(dian)(dian)池三(san)階段充(chong)電(dian)(dian)(dian)過程的波形圖。從圖6 中(zhong)我們可以看出智能充(chong)電(dian)(dian)(dian)系(xi)統能夠(gou)方便地實現各(ge)個充(chong)電(dian)(dian)(dian)狀態的轉換(huan)。

　　5 結語

　　用PIC 單片機可以實(shi)現全數字化(hua)的(de)(de)電(dian)(dian)池充(chong)電(dian)(dian)管理(li)，結構簡單，成本較低，并且具(ju)有很高的(de)(de)靈活(huo)性，通過改變軟件內設(she)置的(de)(de)恒(heng)流參(can)考(kao)值和恒(heng)壓(ya)參(can)考(kao)值就(jiu)可以改變系統的(de)(de)恒(heng)流電(dian)(dian)流和恒(heng)壓(ya)電(dian)(dian)壓(ya)值，使得系統在不改變系統硬(ying)件設(she)計的(de)(de)情況(kuang)下實(shi)現給多(duo)種不同容量的(de)(de)鉛酸蓄電(dian)(dian)池充(chong)電(dian)(dian)。另外可以實(shi)現有效的(de)(de)電(dian)(dian)池充(chong)電(dian)(dian)管理(li)和保(bao)護(hu)功能，達到智能化(hua)控制。