在研究電動車用蓄電池特性及其充電策略和充電算法的基礎上，研制了一款基于P IC16C712單片機的4段式（涓流短時充電、恒流快速充電、恒壓均衡充電、浮充電） 48V （20A?h）蓄電池充電器。該(gai)充(chong)(chong)(chong)電(dian)器能夠(gou)對充(chong)(chong)(chong)電(dian)過程進(jin)行(xing)實時監(jian)測與(yu)控制，使充(chong)(chong)(chong)電(dian)過程按設定的理想充(chong)(chong)(chong)電(dian)曲線進(jin)行(xing)。測試表明，該(gai)充(chong)(chong)(chong)電(dian)器既能完成(cheng)快(kuai)速(su)充(chong)(chong)(chong)電(dian)又能對蓄(xu)電(dian)池(chi)進(jin)行(xing)有(you)效的保(bao)護。

　　近年來，電(dian)動(dong)(dong)車(che)(che)作(zuo)為一種新型的綠色交通工具得到了迅(xun)猛的發展，并呈現出向大功率、高速化(hua)和功能多樣化(hua)的發展趨勢。因此，電(dian)動(dong)(dong)車(che)(che)對蓄電(dian)池(chi)的使用壽命、續(xu)行里(li)程等性能提出的要求比以往更加苛(ke)刻。實(shi)驗(yan)研究表明(ming)：影響蓄電(dian)池(chi)性能的因素多種多樣，如電(dian)動(dong)(dong)車(che)(che)的裝配性能、行駛(shi)電(dian)流、充電(dian)策略等。

　　其中蓄電(dian)(dian)池(chi)(chi)的充電(dian)(dian)過(guo)程(cheng)對其壽命(ming)影(ying)響最大，過(guo)充電(dian)(dian)、充電(dian)(dian)不足是引(yin)起蓄電(dian)(dian)池(chi)(chi)故障(zhang)的主要原因(yin)。所以，必須通過(guo)設計(ji)合(he)理(li)的充電(dian)(dian)策略和充電(dian)(dian)算法(fa)以有效(xiao)地減少(shao)蓄電(dian)(dian)池(chi)(chi)的損傷、減少(shao)充電(dian)(dian)損耗(hao)、提高充電(dian)(dian)速度(du)。

　　為此，開發一種具有自主知識產權，具備適用功率大（ 100 ~500W ） 、性能可靠等特點的電動車用48V （20A?h）蓄電池充電器以滿足電動摩托車、卡丁車、沙地車等電動車發展的迫切需要。該充電器以P IC16C712作為實時監控和中心控制單元，采用PWM DC-DC全橋變換器作為主電路，使得該充電器能夠根據蓄電池的充電特性自動調節輸出電壓、電流，進行智能充電，并且能夠對充電器的運行(xing)狀(zhuang)態進行(xing)實時監測，若有異常(chang)，能及時地進行(xing)保護。此外，該充(chong)電器還(huan)具(ju)有體積(ji)小(xiao)、重量輕、精度(du)高、充(chong)電速度(du)快、性能穩(wen)定(ding)等顯著優(you)點。

　　1 充電器原理與硬件設計

　　1. 1 總體設計

　　目前，電(dian)(dian)(dian)動車電(dian)(dian)(dian)池(chi)作為(wei)一種儲能(neng)裝置，主要以鉛(qian)酸蓄(xu)電(dian)(dian)(dian)池(chi)為(wei)主，充(chong)(chong)電(dian)(dian)(dian)器是(shi)專(zhuan)門(men)針(zhen)對(dui)鉛(qian)酸蓄(xu)電(dian)(dian)(dian)池(chi)所設計(ji)的(de)(de)(de)。傳(chuan)統的(de)(de)(de)蓄(xu)電(dian)(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)(dian)器采用電(dian)(dian)(dian)流/電(dian)(dian)(dian)壓負反饋(kui)的(de)(de)(de)方(fang)法來達到恒(heng)流/恒(heng)壓充(chong)(chong)電(dian)(dian)(dian)的(de)(de)(de)目的(de)(de)(de)，為(wei)了實現充(chong)(chong)電(dian)(dian)(dian)過程各種工作參量的(de)(de)(de)實時(shi)監測及智能(neng)多段式充(chong)(chong)電(dian)(dian)(dian)策略的(de)(de)(de)精確控制(zhi)(zhi)，引入電(dian)(dian)(dian)流/電(dian)(dian)(dian)壓反饋(kui)環，應(ying)用P IC16C712 單片機及相應(ying)的(de)(de)(de)控制(zhi)(zhi)電(dian)(dian)(dian)路，其(qi)硬件結構框圖如圖1所示(shi)，電(dian)(dian)(dian)路圖如圖2所示(shi)。

圖(tu)1 硬件(jian)結構(gou)框圖(tu)

圖(tu)2 電路原理圖(tu)

　

　由(you)圖(tu)1和圖(tu)2可以看出，蓄(xu)電池充電器(qi)主要由(you)開關電源單元(yuan)（電源變(bian)壓器(qi)、整流電路及(ji)濾波電路）和監測與(yu)控制(zhi)單元(yuan)（傳(chuan)感器(qi)、電源專(zhuan)用(yong)集(ji)成(cheng)芯片UC3875及(ji)微控制(zhi)器(qi)P IC16C712）兩部(bu)分組成(cheng)。

在開關電(dian)(dian)源單(dan)元，單(dan)相220V /50Hz的(de)交流(liu)電(dian)(dian)需經過(guo)全橋(qiao)整流(liu)及大電(dian)(dian)容(rong)低頻濾(lv)波穩(wen)壓，然后經過(guo)4只IGBT器件IGBTl ~ IGBT4 組(zu)成的(de)全橋(qiao)逆變器可(ke)(ke)得到(dao)脈寬可(ke)(ke)調的(de)高頻交流(liu)電(dian)(dian)。經高頻變壓器耦合到(dao)副(fu)邊，再經整流(liu)管D9 和D10整流(liu)和電(dian)(dian)感L2、電(dian)(dian)容(rong)C5 濾(lv)波，由(you)此可(ke)(ke)以得到(dao)大小可(ke)(ke)變的(de)低紋(wen)波直流(liu)電(dian)(dian)壓。

　　根據實際需要(yao)，監測與控制單元選擇的(de)單片機(ji)型號(hao)是(shi)由M ICROCH IP公(gong)司推(tui)出(chu)的(de)P IC16C712,其內部有容量為1KB ×14 的(de)EPROM、128 ×8 的(de)RAM,此(ci)外，還包括4個(ge)8位A /D, 3個(ge)定時器和1個(ge)CCP模塊。充電(dian)(dian)器的(de)電(dian)(dian)壓和電(dian)(dian)流(liu)(liu)控制信(xin)號(hao)是(shi)由P IC16C712的(de)CCP模塊輸(shu)出(chu)，經(jing)過F /V轉換(huan)之后輸(shu)入到由美國Unitrode公(gong)司生(sheng)產的(de)移(yi)相式開關(guan)電(dian)(dian)源專用集成芯片UC3875的(de)誤(wu)差放大器輸(shu)入端E /A + ,反相輸(shu)入端E /A - 接主電(dian)(dian)路(lu)輸(shu)出(chu)直(zhi)(zhi)流(liu)(liu)電(dian)(dian)流(liu)(liu)或直(zhi)(zhi)流(liu)(liu)電(dian)(dian)壓反饋信(xin)號(hao)，二(er)者之間(jian)的(de)切換(huan)由P IC16C712單片機(ji)控制中(zhong)間(jian)繼(ji)電(dian)(dian)器實現。

　　1. 2 溫度(du)信號采(cai)集電路(lu)

　　在充(chong)電(dian)(dian)過(guo)程中(zhong)，蓄(xu)(xu)電(dian)(dian)池的(de)(de)(de)溫(wen)(wen)度是一(yi)個非常(chang)重要的(de)(de)(de)參數(shu)。因為鉛酸蓄(xu)(xu)電(dian)(dian)池的(de)(de)(de)電(dian)(dian)壓具(ju)有(you)負溫(wen)(wen)度系數(shu)，其值為- 4mV /℃，對于(yu)一(yi)個在環境溫(wen)(wen)度為25℃時工作很理(li)想(xiang)的(de)(de)(de)充(chong)電(dian)(dian)器(qi)在環境溫(wen)(wen)度降到(dao)0℃時，蓄(xu)(xu)電(dian)(dian)池將(jiang)出現充(chong)電(dian)(dian)不足的(de)(de)(de)現象；而當(dang)環境溫(wen)(wen)度升高到(dao)50℃時，蓄(xu)(xu)電(dian)(dian)池將(jiang)出現過(guo)充(chong)電(dian)(dian)的(de)(de)(de)現象，這(zhe)將(jiang)導(dao)致蓄(xu)(xu)電(dian)(dian)池壽命縮短。

　　因此，設(she)計良好的(de)充(chong)電(dian)(dian)器(qi)應具有溫(wen)度(du)(du)(du)檢測功能(neng)并能(neng)夠根(gen)據(ju)不同的(de)環(huan)境溫(wen)度(du)(du)(du)調整充(chong)電(dian)(dian)過(guo)程(cheng)中的(de)各轉換電(dian)(dian)壓值；同時，充(chong)電(dian)(dian)器(qi)還應具備(bei)溫(wen)度(du)(du)(du)保護(hu)功能(neng)，在充(chong)電(dian)(dian)過(guo)程(cheng)中，當蓄電(dian)(dian)池(chi)溫(wen)度(du)(du)(du)超出限定的(de)溫(wen)度(du)(du)(du)范(fan)圍時充(chong)電(dian)(dian)器(qi)應立(li)即停(ting)止充(chong)電(dian)(dian)或進入涓流充(chong)電(dian)(dian)，并且PIC16C712應點亮故障指示(shi)燈以(yi)提示(shi)用戶出現何種(zhong)異常(chang)。

　　由上分析可(ke)知，溫(wen)(wen)度(du)檢測(ce)(ce)的(de)(de)準確性將(jiang)在很大程度(du)上影響充(chong)電(dian)器的(de)(de)性能。為(wei)此，利用LM61B IM3溫(wen)(wen)度(du)傳感器設計了溫(wen)(wen)度(du)檢測(ce)(ce)電(dian)路(lu)，如圖3所示，該傳感器可(ke)以測(ce)(ce)量的(de)(de)溫(wen)(wen)度(du)范圍(wei)為(wei)- 25℃~ + 85℃，線性度(du)為(wei)10mV /℃，即：

圖3 溫度(du)采集電路圖

　

　2 充電策略與算法設計

　　2. 1 充電(dian)流程

　　根據(ju)鉛酸蓄電(dian)(dian)池的特(te)點，將其充(chong)(chong)(chong)電(dian)(dian)過(guo)程(cheng)分為4個階(jie)段：涓流(liu)短時充(chong)(chong)(chong)電(dian)(dian)、恒(heng)流(liu)快速(su)充(chong)(chong)(chong)電(dian)(dian)、恒(heng)壓均衡充(chong)(chong)(chong)電(dian)(dian)、浮(fu)充(chong)(chong)(chong)電(dian)(dian)。其中(zhong)第一階(jie)段和第二階(jie)段均為恒(heng)流(liu)充(chong)(chong)(chong)電(dian)(dian)，采取這種策略是因為實(shi)驗研究證明多(duo)段恒(heng)流(liu)充(chong)(chong)(chong)電(dian)(dian)有利于(yu)充(chong)(chong)(chong)入更(geng)多(duo)的電(dian)(dian)量且可以減少對蓄電(dian)(dian)池的損(sun)傷、延長(chang)使(shi)用(yong)壽(shou)命。充(chong)(chong)(chong)電(dian)(dian)過(guo)程(cheng)中(zhong)各個階(jie)段充(chong)(chong)(chong)電(dian)(dian)電(dian)(dian)壓、充(chong)(chong)(chong)電(dian)(dian)電(dian)(dian)流(liu)隨時間變(bian)化(hua)的曲(qu)線如(ru)圖4所示。

圖4 充電流程曲(qu)線(xian)。

（1）涓流短時充電（ T0 - T1 ）
 

　　

       蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)在(zai)(zai)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)初期可(ke)能已(yi)處于(yu)深度(du)放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)狀態（或可(ke)能已(yi)經處于(yu)受(shou)損的(de)(de)(de)(de)(de)狀態） ,為避免對蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)過(guo)大造(zao)成"熱失控(kong)", P IC16C712單片機通過(guo)實(shi)時(shi)(shi)監測蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)，對蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)進行穩(wen)定的(de)(de)(de)(de)(de)小電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)涓流(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，這(zhe)樣有利于(yu)激活蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)內的(de)(de)(de)(de)(de)反(fan)應物質(zhi)，部分恢復受(shou)損的(de)(de)(de)(de)(de)蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)單元(yuan)。在(zai)(zai)涓流(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)階段(duan)，蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)開(kai)始緩慢上升，當蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)上升到能接受(shou)大電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)(de)(de)閾值時(shi)(shi)則轉入恒流(liu)快(kuai)速充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)階段(duan)。

　　（2）恒(heng)流快速充電（ T1 - T2 ）

　　該階段充電電流保持恒(heng)定(ding)，蓄電池電壓(ya)上(shang)升(sheng)較快，當電壓(ya)上(shang)升(sheng)至均(jun)衡(heng)(heng)充電壓(ya)閾值時(shi)，則轉入恒(heng)壓(ya)均(jun)衡(heng)(heng)充電階段。

　　（3）恒壓均(jun)衡充電（ T2 - T3 ）

　　該階(jie)段(duan)充(chong)電(dian)電(dian)壓保持恒(heng)定，蓄(xu)電(dian)池容量快速恢復。充(chong)電(dian)電(dian)流(liu)逐漸(jian)減小，當電(dian)流(liu)下降至某一(yi)閾值(zhi)時，自動轉入浮充(chong)電(dian)階(jie)段(duan)。

　　（4）浮充電（ T3 - ）

　　該階(jie)段主要用來補充(chong)蓄電池自放(fang)電所消耗的能(neng)量，此時標志(zhi)著充(chong)電過(guo)程結(jie)束。

　　2. 2 關鍵技術

　　2. 2. 1 恒(heng)流充(chong)電電流的選擇

　　充電(dian)過程(cheng)(cheng)中包含兩個恒流充電(dian)過程(cheng)(cheng)：涓(juan)流短(duan)時充電(dian)和(he)恒流快速(su)充電(dian)。

　　涓流短時充(chong)電(dian)電(dian)流的選擇應(ying)該根(gen)據蓄電(dian)池的剩余電(dian)量(liang)進行選擇。經過(guo)大量(liang)的實驗研(yan)究表明(ming)，對于放(fang)電(dian)深度(du)為80% ~100%的蓄電(dian)池，充(chong)電(dian)電(dian)流定在0. 2~0. 4A比較合(he)適(shi)。

　　恒流(liu)(liu)快(kuai)速充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)的選擇要(yao)綜合考慮蓄(xu)電(dian)(dian)(dian)(dian)(dian)池容量(liang)(liang)、內阻、對(dui)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)時間的要(yao)求、制造成本等多(duo)方面因素。按(an)照應用(yong)經(jing)驗，普遍(bian)認為，該(gai)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)設置為0. 15~0. 3 C對(dui)蓄(xu)電(dian)(dian)(dian)(dian)(dian)池比較(jiao)合適(shi)。電(dian)(dian)(dian)(dian)(dian)動自(zi)行車用(yong)48V （20A?h）鉛酸蓄(xu)電(dian)(dian)(dian)(dian)(dian)池時采用(yong)的是(shi)20℃標稱，但是(shi)實際容量(liang)(liang)往(wang)往(wang)只能達到15~17A?h.因此，依(yi)據該(gai)經(jing)驗看法，充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)應大致定在2. 25~5. 1 A之間，平均為3. 675A.

　　有設計者認(ren)為(wei)(wei)減小充(chong)(chong)(chong)電(dian)(dian)電(dian)(dian)流具(ju)有3個方面的(de)優點： （1）可以使(shi)單位時(shi)間內產生的(de)熱量降(jiang)低，有利(li)于在蓄電(dian)(dian)池的(de)使(shi)用(yong)(yong)壽命末期和夏季保證(zheng)充(chong)(chong)(chong)電(dian)(dian)質量；（2）可以減少極化(hua)（歐姆(mu)極化(hua)、濃差極化(hua)、電(dian)(dian)化(hua)學(xue)極化(hua)）現象的(de)影響，有利(li)于冬季充(chong)(chong)(chong)電(dian)(dian)； （ 3）可以降(jiang)低充(chong)(chong)(chong)電(dian)(dian)器的(de)輸(shu)出(chu)功(gong)率，制造成本下(xia)降(jiang)。但(dan)是(shi)也有設計者認(ren)為(wei)(wei)，電(dian)(dian)動(dong)車(che)用(yong)(yong)蓄電(dian)(dian)池以較大電(dian)(dian)流短時(shi)間放(fang)電(dian)(dian)，充(chong)(chong)(chong)電(dian)(dian)接(jie)受率高(gao)， 所以可以增大充(chong)(chong)(chong)電(dian)(dian)電(dian)(dian)流（甚至推薦為(wei)(wei)5A）以提高(gao)充(chong)(chong)(chong)電(dian)(dian)速度。

　　通過(guo)對浙(zhe)江天能、浙(zhe)江超威(wei)、英國IBT和日本松(song)下等(deng)電(dian)動車用48V （ 20A?h）蓄電(dian)池(chi)進行(xing)了長期的可靠(kao)性實(shi)驗。在充電(dian)時，采用平均(jun)值(zhi)為3. 5A并根(gen)據環境溫度(du)動態小幅(fu)度(du)調整的恒流快速充電(dian)電(dian)流，蓄電(dian)池(chi)沒有明顯發熱，充電(dian)過(guo)程(cheng)穩定可靠(kao)。

　　2. 2. 2 恒壓充電(dian)電(dian)壓的選擇

　　恒(heng)壓充電電壓的選擇非常關鍵，因為它不(bu)能在很寬的范圍內調整。確定這個參數不(bu)但需要對蓄電池有較為深(shen)人的了解，還需要對充電策略(lve)等因素進(jin)行考慮(lv)。

　　蓄(xu)電(dian)(dian)池(chi)在充(chong)電(dian)(dian)時(shi)，正極(ji)上的(de)(de)析(xi)氧速率(lv)與施(shi)加的(de)(de)充(chong)電(dian)(dian)電(dian)(dian)壓成(cheng)(cheng)正比，而氧傳輸到負極(ji)并溶解在負極(ji)表面液膜中(zhong)進行還原的(de)(de)速度受到限(xian)制，即氧的(de)(de)析(xi)出(chu)快于還原時(shi)，復(fu)合(he)效率(lv)就下降，造成(cheng)(cheng)失水(shui)(shui)。通常情況(kuang)下， 48V 閥(fa)控(kong)鉛酸蓄(xu)電(dian)(dian)池(chi)的(de)(de)浮充(chong)電(dian)(dian)壓設置在55 -55. 6 V,可(ke)以(yi)保(bao)證(zheng)蓄(xu)電(dian)(dian)池(chi)長期(qi)處于充(chong)電(dian)(dian)狀態且極(ji)少失水(shui)(shui)。循(xun)環使(shi)用蓄(xu)電(dian)(dian)池(chi)最高充(chong)電(dian)(dian)電(dian)(dian)壓為(wei)58. 8V,如果超過(guo)就會(hui)使(shi)復(fu)合(he)效率(lv)急劇下降，從而影響電(dian)(dian)池(chi)的(de)(de)使(shi)用壽(shou)命。

　　2. 2. 3 蓄(xu)電池是(shi)否充滿的判定

　　對(dui)蓄(xu)電(dian)(dian)(dian)(dian)池在(zai)充(chong)電(dian)(dian)(dian)(dian)過程中是(shi)否(fou)已充(chong)滿的(de)判(pan)斷是(shi)充(chong)電(dian)(dian)(dian)(dian)器的(de)重要(yao)指標。如果(guo)蓄(xu)電(dian)(dian)(dian)(dian)池未充(chong)滿而錯判(pan)為充(chong)滿將導(dao)致蓄(xu)電(dian)(dian)(dian)(dian)池欠充(chong)；反之，則將導(dao)致蓄(xu)電(dian)(dian)(dian)(dian)池過充(chong)。這兩種情況(kuang)都會(hui)嚴重影響(xiang)蓄(xu)電(dian)(dian)(dian)(dian)池的(de)壽命。目前判(pan)斷蓄(xu)電(dian)(dian)(dian)(dian)池是(shi)否(fou)充(chong)滿的(de)控(kong)(kong)制準(zhun)則有：定(ding)時控(kong)(kong)制、電(dian)(dian)(dian)(dian)壓(ya)控(kong)(kong)制（包(bao)含最(zui)高電(dian)(dian)(dian)(dian)壓(ya)、電(dian)(dian)(dian)(dian)壓(ya)負增(zeng)量(liang)(liang)、電(dian)(dian)(dian)(dian)壓(ya)零增(zeng)量(liang)(liang)等(deng)）、溫(wen)(wen)度(du)控(kong)(kong)制（包(bao)括最(zui)高溫(wen)(wen)度(du)、最(zui)高溫(wen)(wen)升、溫(wen)(wen)度(du)變(bian)化(hua)率等(deng)）、電(dian)(dian)(dian)(dian)流控(kong)(kong)制（包(bao)含最(zui)小(xiao)電(dian)(dian)(dian)(dian)流、電(dian)(dian)(dian)(dian)流變(bian)化(hua)量(liang)(liang)等(deng)）、動態內阻控(kong)(kong)制等(deng)。

　　在(zai)(zai)實際應用中，如果以單一的(de)(de)(de)(de)控制(zhi)的(de)(de)(de)(de)方式都將不可避免地存在(zai)(zai)缺陷。比(bi)如，在(zai)(zai)恒(heng)壓(ya)(ya)均衡充電(dian)(dian)(dian)(dian)過(guo)程中，電(dian)(dian)(dian)(dian)壓(ya)(ya)保持(chi)恒(heng)定(ding)(ding)，電(dian)(dian)(dian)(dian)流(liu)會(hui)隨(sui)(sui)著充電(dian)(dian)(dian)(dian)的(de)(de)(de)(de)進(jin)程逐(zhu)漸減小，當小到一定(ding)(ding)程度(du)(du)(du)電(dian)(dian)(dian)(dian)流(liu)將會(hui)恒(heng)定(ding)(ding)，不再下降，這(zhe)時的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)能(neng)向化(hua)(hua)學能(neng)的(de)(de)(de)(de)轉化(hua)(hua)效率已經很低，電(dian)(dian)(dian)(dian)能(neng)主要用于電(dian)(dian)(dian)(dian)解水，一般認為這(zhe)個(ge)電(dian)(dian)(dian)(dian)流(liu)為蓄(xu)電(dian)(dian)(dian)(dian)池(chi)恒(heng)壓(ya)(ya)均衡充電(dian)(dian)(dian)(dian)的(de)(de)(de)(de)殘(can)余(yu)(yu)電(dian)(dian)(dian)(dian)流(liu)。然而，殘(can)余(yu)(yu)電(dian)(dian)(dian)(dian)流(liu)的(de)(de)(de)(de)大小將隨(sui)(sui)著環(huan)境溫(wen)度(du)(du)(du)的(de)(de)(de)(de)變化(hua)(hua)而變化(hua)(hua)，也就是說殘(can)余(yu)(yu)電(dian)(dian)(dian)(dian)流(liu)是一個(ge)受內、外界多重因素影響的(de)(de)(de)(de)動(dong)態(tai)值。若沒有溫(wen)度(du)(du)(du)控制(zhi)，最高(gao)充電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓(ya)(ya)和切換電(dian)(dian)(dian)(dian)流(liu)都只(zhi)(zhi)能(neng)設置成定(ding)(ding)值，而這(zhe)個(ge)定(ding)(ding)值無論(lun)如何設置，都只(zhi)(zhi)能(neng)在(zai)(zai)一個(ge)相(xiang)對較(jiao)小的(de)(de)(de)(de)范(fan)圍內成為最佳(jia)設置。為此，設計的(de)(de)(de)(de)充電(dian)(dian)(dian)(dian)器通過(guo)對電(dian)(dian)(dian)(dian)壓(ya)(ya)、電(dian)(dian)(dian)(dian)流(liu)、溫(wen)度(du)(du)(du)等(deng)工作參數進(jin)行(xing)實時檢測，并按模糊(hu)理(li)論(lun)的(de)(de)(de)(de)評判規則對這(zhe)些參數進(jin)行(xing)綜合分析，從而確定(ding)(ding)蓄(xu)電(dian)(dian)(dian)(dian)池(chi)是否充滿。

2. 3 軟件架構 
 

　　P IC16C712單片機(ji)的(de)(de)軟(ruan)件模塊(kuai)主要完成(cheng)對傳(chuan)感器的(de)(de)輸(shu)入信(xin)號(hao)進行(xing)采(cai)集、對電(dian)源專(zhuan)用芯片UC3875進行(xing)控制、對異(yi)常進行(xing)處理(li)等工(gong)作。在設計過程中，軟(ruan)件系統(tong)每隔10 s檢(jian)測(ce)(ce)一次(ci)電(dian)壓和電(dian)流； 每隔20 s檢(jian)測(ce)(ce)一次(ci)溫度(du)。如有異(yi)常，系統(tong)將通過LED提示(shi)用戶出(chu)現何種異(yi)常并采(cai)取相應的(de)(de)保(bao)護措施。整個系統(tong)的(de)(de)軟(ruan)件架構(gou)，如圖5所示(shi)。

圖5 軟件架構

　　　對充(chong)電(dian)器樣機進行的測試表明(ming)蓄(xu)電(dian)池充(chong)電(dian)器具有如下特性：

　　（1）輸入電壓： 220 Vac;

　　（2）輸出電壓： 40~60V;

　　（3）輸出電流： < 10A;

　　（4）功率因(yin)數： > 0. 99;

　　（5）充電噪聲： < 20dB;

　　（6）充(chong)電時(shi)間： 6~8h;

　　（7）充電效率： > 85%;

　　（8）充電溫升： < 15℃；

　　（9）質  量： < 0. 6kg.

　　此外，充電器還具有故障診斷功能。當充電回路電流或電壓過大、開路、短路時，充電器自(zi)動切斷主電路，同時(shi)點亮相應的LED故(gu)障指(zhi)示(shi)(shi)燈指(zhi)示(shi)(shi)故(gu)障原因，具有良好的保(bao)護(hu)特性(xing)。