電動車用48V （20A?h）蓄電池充電器
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。該充(chong)(chong)(chong)電(dian)(dian)器能夠對(dui)充(chong)(chong)(chong)電(dian)(dian)過(guo)程(cheng)進(jin)(jin)行(xing)(xing)實時監測與控制，使充(chong)(chong)(chong)電(dian)(dian)過(guo)程(cheng)按設定的理想充(chong)(chong)(chong)電(dian)(dian)曲線(xian)進(jin)(jin)行(xing)(xing)。測試表(biao)明，該充(chong)(chong)(chong)電(dian)(dian)器既能完(wan)成快(kuai)速(su)充(chong)(chong)(chong)電(dian)(dian)又(you)能對(dui)蓄電(dian)(dian)池進(jin)(jin)行(xing)(xing)有(you)效的保護。
近年來，電(dian)(dian)(dian)動(dong)車作為一種(zhong)新型的綠色(se)交(jiao)通工具得(de)到(dao)了迅(xun)猛(meng)的發展，并(bing)呈現出向大功(gong)率、高(gao)速化和功(gong)能多樣化的發展趨勢(shi)。因(yin)此，電(dian)(dian)(dian)動(dong)車對蓄電(dian)(dian)(dian)池的使(shi)用壽命、續行里(li)程等性能提出的要求(qiu)比以往更加苛刻。實驗研究(jiu)表明(ming)：影響(xiang)蓄電(dian)(dian)(dian)池性能的因(yin)素(su)多種(zhong)多樣，如電(dian)(dian)(dian)動(dong)車的裝配性能、行駛電(dian)(dian)(dian)流(liu)、充電(dian)(dian)(dian)策略等。
其中蓄電(dian)池(chi)的(de)(de)充(chong)(chong)電(dian)過程(cheng)對(dui)其壽命影響最(zui)大，過充(chong)(chong)電(dian)、充(chong)(chong)電(dian)不(bu)足(zu)是引起(qi)蓄電(dian)池(chi)故障的(de)(de)主要原(yuan)因。所以，必(bi)須通過設計(ji)合理的(de)(de)充(chong)(chong)電(dian)策略和充(chong)(chong)電(dian)算法以有效地(di)減少(shao)蓄電(dian)池(chi)的(de)(de)損傷、減少(shao)充(chong)(chong)電(dian)損耗、提高充(chong)(chong)電(dian)速(su)度。
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(de)運行狀態進行實時監測，若有異常(chang)，能及時地進行保護。此外，該充電器還具有體積小(xiao)、重量輕、精度(du)高、充電速度(du)快、性能穩定等顯著優點。
1 充電器原(yuan)理與硬件設(she)計
1. 1 總體(ti)設(she)計
目前，電(dian)動車電(dian)池作為一種儲能(neng)裝置，主(zhu)要(yao)以鉛(qian)酸蓄電(dian)池為主(zhu)，充(chong)電(dian)器是專門(men)針對鉛(qian)酸蓄電(dian)池所設計(ji)的(de)(de)。傳(chuan)統的(de)(de)蓄電(dian)池充(chong)電(dian)器采用電(dian)流/電(dian)壓負反(fan)饋的(de)(de)方(fang)法來(lai)達到恒(heng)流/恒(heng)壓充(chong)電(dian)的(de)(de)目的(de)(de)，為了實(shi)(shi)現充(chong)電(dian)過程各種工作參(can)量的(de)(de)實(shi)(shi)時監(jian)測及智能(neng)多段式充(chong)電(dian)策略的(de)(de)精確控制，引(yin)入電(dian)流/電(dian)壓反(fan)饋環，應(ying)用P IC16C712 單片機及相應(ying)的(de)(de)控制電(dian)路(lu)，其硬件結構(gou)框圖(tu)(tu)如圖(tu)(tu)1所示，電(dian)路(lu)圖(tu)(tu)如圖(tu)(tu)2所示。
圖1 硬件結構框圖
圖2 電路原理圖
由圖1和圖2可以(yi)看出(chu)，蓄電(dian)(dian)池(chi)充電(dian)(dian)器(qi)主要(yao)由開關電(dian)(dian)源(yuan)(yuan)單元（電(dian)(dian)源(yuan)(yuan)變壓(ya)器(qi)、整流電(dian)(dian)路(lu)及濾波電(dian)(dian)路(lu)）和監測(ce)與控(kong)制單元（傳感器(qi)、電(dian)(dian)源(yuan)(yuan)專用(yong)集(ji)成芯片UC3875及微控(kong)制器(qi)P IC16C712）兩部分組成。
在開關電(dian)源單(dan)元，單(dan)相220V /50Hz的(de)(de)交(jiao)流(liu)(liu)電(dian)需經(jing)過全橋整流(liu)(liu)及大電(dian)容低頻(pin)(pin)濾(lv)波穩(wen)壓，然后經(jing)過4只IGBT器(qi)件IGBTl ~ IGBT4 組成的(de)(de)全橋逆變器(qi)可(ke)得到脈寬可(ke)調的(de)(de)高(gao)頻(pin)(pin)交(jiao)流(liu)(liu)電(dian)。經(jing)高(gao)頻(pin)(pin)變壓器(qi)耦合到副(fu)邊，再經(jing)整流(liu)(liu)管D9 和D10整流(liu)(liu)和電(dian)感(gan)L2、電(dian)容C5 濾(lv)波，由此可(ke)以得到大小可(ke)變的(de)(de)低紋波直流(liu)(liu)電(dian)壓。
根(gen)據實(shi)際需要，監測與控制單元(yuan)選擇的(de)(de)單片機型號是(shi)(shi)由(you)M ICROCH IP公司推出的(de)(de)P IC16C712,其(qi)內(nei)部有容量為1KB ×14 的(de)(de)EPROM、128 ×8 的(de)(de)RAM,此外，還包括(kuo)4個(ge)8位A /D, 3個(ge)定時(shi)器(qi)和1個(ge)CCP模(mo)塊(kuai)。充電器(qi)的(de)(de)電壓(ya)和電流(liu)(liu)控制信號是(shi)(shi)由(you)P IC16C712的(de)(de)CCP模(mo)塊(kuai)輸(shu)出，經(jing)過F /V轉換之后輸(shu)入到由(you)美國Unitrode公司生產的(de)(de)移相(xiang)式開(kai)關電源專用集成芯片UC3875的(de)(de)誤差放大器(qi)輸(shu)入端(duan)E /A + ,反(fan)(fan)相(xiang)輸(shu)入端(duan)E /A - 接主電路輸(shu)出直流(liu)(liu)電流(liu)(liu)或直流(liu)(liu)電壓(ya)反(fan)(fan)饋信號，二者之間的(de)(de)切(qie)換由(you)P IC16C712單片機控制中間繼(ji)電器(qi)實(shi)現。
1. 2 溫(wen)度(du)信(xin)號采集電路
在充電(dian)(dian)過(guo)程中，蓄電(dian)(dian)池(chi)(chi)的(de)(de)溫度是一個非常重要的(de)(de)參數。因(yin)為(wei)鉛酸蓄電(dian)(dian)池(chi)(chi)的(de)(de)電(dian)(dian)壓(ya)具(ju)有負(fu)溫度系(xi)數，其值(zhi)為(wei)- 4mV /℃，對于一個在環(huan)(huan)境(jing)溫度為(wei)25℃時(shi)工作很理想的(de)(de)充電(dian)(dian)器在環(huan)(huan)境(jing)溫度降到0℃時(shi)，蓄電(dian)(dian)池(chi)(chi)將(jiang)出(chu)現充電(dian)(dian)不足的(de)(de)現象；而當(dang)環(huan)(huan)境(jing)溫度升高到50℃時(shi)，蓄電(dian)(dian)池(chi)(chi)將(jiang)出(chu)現過(guo)充電(dian)(dian)的(de)(de)現象，這將(jiang)導(dao)致蓄電(dian)(dian)池(chi)(chi)壽命縮短。
因此，設計(ji)良好的(de)(de)充(chong)電(dian)器(qi)應(ying)(ying)具有溫(wen)(wen)度(du)(du)檢測功(gong)能(neng)并能(neng)夠根(gen)據(ju)不同(tong)(tong)的(de)(de)環境溫(wen)(wen)度(du)(du)調整充(chong)電(dian)過(guo)程中(zhong)(zhong)的(de)(de)各轉換電(dian)壓值(zhi)；同(tong)(tong)時(shi)，充(chong)電(dian)器(qi)還應(ying)(ying)具備溫(wen)(wen)度(du)(du)保護功(gong)能(neng)，在充(chong)電(dian)過(guo)程中(zhong)(zhong)，當蓄電(dian)池溫(wen)(wen)度(du)(du)超出限定的(de)(de)溫(wen)(wen)度(du)(du)范圍時(shi)充(chong)電(dian)器(qi)應(ying)(ying)立(li)即(ji)停止充(chong)電(dian)或進入涓流充(chong)電(dian)，并且(qie)PIC16C712應(ying)(ying)點亮故障指示燈以提示用戶出現何種(zhong)異常(chang)。
由(you)上分析可知，溫(wen)(wen)度檢測的準確性(xing)將在很大(da)程度上影響(xiang)充電器(qi)的性(xing)能(neng)。為此，利用LM61B IM3溫(wen)(wen)度傳(chuan)感器(qi)設計了(le)溫(wen)(wen)度檢測電路(lu)，如(ru)圖3所示，該傳(chuan)感器(qi)可以測量的溫(wen)(wen)度范圍(wei)為- 25℃~ + 85℃，線性(xing)度為10mV /℃，即(ji)：
圖3 溫度采集電路圖
2 充電(dian)策(ce)略與算法設計
2. 1 充電(dian)流(liu)程
根據(ju)鉛酸蓄電(dian)(dian)池(chi)的特點，將其充(chong)(chong)電(dian)(dian)過(guo)程(cheng)分為(wei)(wei)4個階段(duan)：涓流(liu)短時充(chong)(chong)電(dian)(dian)、恒(heng)(heng)流(liu)快速充(chong)(chong)電(dian)(dian)、恒(heng)(heng)壓均(jun)衡(heng)充(chong)(chong)電(dian)(dian)、浮充(chong)(chong)電(dian)(dian)。其中(zhong)第一(yi)階段(duan)和(he)第二(er)階段(duan)均(jun)為(wei)(wei)恒(heng)(heng)流(liu)充(chong)(chong)電(dian)(dian)，采取這(zhe)種策略是因為(wei)(wei)實(shi)驗研究證明多(duo)段(duan)恒(heng)(heng)流(liu)充(chong)(chong)電(dian)(dian)有(you)利于充(chong)(chong)入更多(duo)的電(dian)(dian)量且可以減少對(dui)蓄電(dian)(dian)池(chi)的損(sun)傷(shang)、延長使用壽命。充(chong)(chong)電(dian)(dian)過(guo)程(cheng)中(zhong)各個階段(duan)充(chong)(chong)電(dian)(dian)電(dian)(dian)壓、充(chong)(chong)電(dian)(dian)電(dian)(dian)流(liu)隨時間變化的曲線如圖4所(suo)示。
圖4 充電流程曲線。
（1）涓流短時充電（ T0 - T1 ）
蓄電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)在充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)初期可能已處于深度放電(dian)(dian)(dian)(dian)(dian)(dian)狀(zhuang)態(tai)（或可能已經處于受(shou)損的(de)狀(zhuang)態(tai)） ,為(wei)避免對(dui)蓄電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流過大(da)造(zao)成(cheng)"熱(re)失控", P IC16C712單(dan)片機通過實時(shi)監測(ce)蓄電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)壓，對(dui)蓄電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)進行(xing)穩(wen)定(ding)的(de)小電(dian)(dian)(dian)(dian)(dian)(dian)流涓流充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)，這樣(yang)有利于激活蓄電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)內的(de)反(fan)應物質，部分(fen)恢復受(shou)損的(de)蓄電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)單(dan)元。在涓流充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)階段(duan)，蓄電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)壓開(kai)始(shi)緩慢上(shang)升，當(dang)蓄電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)壓上(shang)升到能接(jie)受(shou)大(da)電(dian)(dian)(dian)(dian)(dian)(dian)流充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)的(de)閾值時(shi)則轉入恒流快速充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)階段(duan)。
（2）恒流快速(su)充電（ T1 - T2 ）
該(gai)階段充(chong)電(dian)電(dian)流保持恒定(ding)，蓄電(dian)池電(dian)壓上升較快，當電(dian)壓上升至均衡充(chong)電(dian)壓閾(yu)值(zhi)時，則(ze)轉入(ru)恒壓均衡充(chong)電(dian)階段。
（3）恒壓均衡(heng)充電（ T2 - T3 ）
該階段(duan)充(chong)電(dian)電(dian)壓保持恒定(ding)，蓄電(dian)池容量(liang)快速恢復。充(chong)電(dian)電(dian)流逐(zhu)漸減(jian)小(xiao)，當電(dian)流下降至(zhi)某一閾值時，自動轉入浮充(chong)電(dian)階段(duan)。
（4）浮充電（ T3 - ）
該階(jie)段(duan)主(zhu)要(yao)用(yong)來補(bu)充(chong)蓄電池自(zi)放電所消耗的能量，此時(shi)標志著(zhu)充(chong)電過程(cheng)結(jie)束。
2. 2 關鍵技術(shu)
2. 2. 1 恒流(liu)充電(dian)電(dian)流(liu)的選(xuan)擇
充(chong)(chong)電過(guo)程中包含兩個恒流充(chong)(chong)電過(guo)程：涓流短(duan)時充(chong)(chong)電和恒流快速(su)充(chong)(chong)電。
涓流短時充電(dian)(dian)(dian)電(dian)(dian)(dian)流的(de)選擇應該根(gen)據蓄電(dian)(dian)(dian)池的(de)剩余電(dian)(dian)(dian)量進行選擇。經過大量的(de)實驗研究(jiu)表明，對(dui)于(yu)放電(dian)(dian)(dian)深度為80% ~100%的(de)蓄電(dian)(dian)(dian)池，充電(dian)(dian)(dian)電(dian)(dian)(dian)流定在0. 2~0. 4A比較合適。
恒流快速充(chong)電(dian)(dian)電(dian)(dian)流的(de)選擇要綜合考慮蓄(xu)電(dian)(dian)池(chi)容(rong)量(liang)、內阻(zu)、對(dui)充(chong)電(dian)(dian)時(shi)間的(de)要求(qiu)、制造成本等多方面因(yin)素。按照應(ying)用經(jing)驗，普(pu)遍認為，該(gai)充(chong)電(dian)(dian)電(dian)(dian)流設置為0. 15~0. 3 C對(dui)蓄(xu)電(dian)(dian)池(chi)比較合適(shi)。電(dian)(dian)動自行車用48V （20A?h）鉛酸蓄(xu)電(dian)(dian)池(chi)時(shi)采用的(de)是(shi)20℃標稱，但是(shi)實際容(rong)量(liang)往(wang)往(wang)只能達到15~17A?h.因(yin)此(ci)，依(yi)據該(gai)經(jing)驗看(kan)法，充(chong)電(dian)(dian)電(dian)(dian)流應(ying)大致定在2. 25~5. 1 A之(zhi)間，平均為3. 675A.
有(you)(you)(you)設計者認(ren)為(wei)減(jian)小充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流具有(you)(you)(you)3個(ge)方面的(de)優(you)點： （1）可以(yi)使單位(wei)時(shi)(shi)間內產生的(de)熱量降(jiang)低，有(you)(you)(you)利于在蓄電(dian)(dian)(dian)池的(de)使用壽命末期和夏季保證充(chong)(chong)電(dian)(dian)(dian)質量；（2）可以(yi)減(jian)少極(ji)(ji)化(hua)（歐姆極(ji)(ji)化(hua)、濃差(cha)極(ji)(ji)化(hua)、電(dian)(dian)(dian)化(hua)學極(ji)(ji)化(hua)）現象的(de)影響，有(you)(you)(you)利于冬季充(chong)(chong)電(dian)(dian)(dian)； （ 3）可以(yi)降(jiang)低充(chong)(chong)電(dian)(dian)(dian)器的(de)輸出功(gong)率，制造成本(ben)下降(jiang)。但是也有(you)(you)(you)設計者認(ren)為(wei)，電(dian)(dian)(dian)動(dong)車(che)用蓄電(dian)(dian)(dian)池以(yi)較大(da)電(dian)(dian)(dian)流短時(shi)(shi)間放電(dian)(dian)(dian)，充(chong)(chong)電(dian)(dian)(dian)接受(shou)率高， 所以(yi)可以(yi)增大(da)充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流（甚至推薦為(wei)5A）以(yi)提高充(chong)(chong)電(dian)(dian)(dian)速(su)度。
通過對浙(zhe)江(jiang)天能、浙(zhe)江(jiang)超威、英國(guo)IBT和日本松下等電動(dong)車(che)用(yong)48V （ 20A?h）蓄電池進(jin)行了長期的可靠性實驗。在充電時，采(cai)用(yong)平均值為3. 5A并(bing)根據環境(jing)溫度動(dong)態小幅度調整(zheng)的恒(heng)流(liu)(liu)快速充電電流(liu)(liu)，蓄電池沒有明(ming)顯(xian)發熱，充電過程穩定(ding)可靠。
2. 2. 2 恒壓充電電壓的選擇
恒(heng)壓充(chong)電電壓的選擇非常關鍵，因為它不能在很(hen)寬的范(fan)圍內調(diao)整。確定這個(ge)參數不但需(xu)要(yao)對蓄電池(chi)有較(jiao)為深人的了解(jie)，還需(xu)要(yao)對充(chong)電策略等因素進行(xing)考慮。
蓄電(dian)池在充(chong)電(dian)時(shi)，正(zheng)極(ji)上(shang)的(de)(de)析氧速(su)率與施加的(de)(de)充(chong)電(dian)電(dian)壓(ya)成正(zheng)比，而(er)氧傳輸到負極(ji)并(bing)溶解(jie)在負極(ji)表面液膜(mo)中進(jin)行還原的(de)(de)速(su)度受到限(xian)制，即氧的(de)(de)析出(chu)快于還原時(shi)，復(fu)合(he)效(xiao)率就下降，造成失(shi)水(shui)。通常(chang)情(qing)況下， 48V 閥控(kong)鉛酸蓄電(dian)池的(de)(de)浮(fu)充(chong)電(dian)壓(ya)設置在55 -55. 6 V,可(ke)以保證(zheng)蓄電(dian)池長期處于充(chong)電(dian)狀態且極(ji)少失(shi)水(shui)。循環使(shi)用(yong)蓄電(dian)池最高充(chong)電(dian)電(dian)壓(ya)為58. 8V,如果(guo)超過就會使(shi)復(fu)合(he)效(xiao)率急(ji)劇下降，從(cong)而(er)影(ying)響電(dian)池的(de)(de)使(shi)用(yong)壽命。
2. 2. 3 蓄(xu)電池(chi)是否充滿的判定
對(dui)蓄(xu)電(dian)(dian)(dian)(dian)(dian)池(chi)在充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)過程中是(shi)否(fou)已充(chong)(chong)(chong)滿(man)(man)的(de)判(pan)斷是(shi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器的(de)重要指(zhi)標。如(ru)果蓄(xu)電(dian)(dian)(dian)(dian)(dian)池(chi)未充(chong)(chong)(chong)滿(man)(man)而錯判(pan)為充(chong)(chong)(chong)滿(man)(man)將導(dao)致(zhi)蓄(xu)電(dian)(dian)(dian)(dian)(dian)池(chi)欠(qian)充(chong)(chong)(chong)；反之(zhi)，則將導(dao)致(zhi)蓄(xu)電(dian)(dian)(dian)(dian)(dian)池(chi)過充(chong)(chong)(chong)。這(zhe)兩種(zhong)情況都(dou)會嚴重影響蓄(xu)電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)壽命。目前(qian)判(pan)斷蓄(xu)電(dian)(dian)(dian)(dian)(dian)池(chi)是(shi)否(fou)充(chong)(chong)(chong)滿(man)(man)的(de)控(kong)制準則有：定時(shi)控(kong)制、電(dian)(dian)(dian)(dian)(dian)壓(ya)控(kong)制（包(bao)含最(zui)高電(dian)(dian)(dian)(dian)(dian)壓(ya)、電(dian)(dian)(dian)(dian)(dian)壓(ya)負增量、電(dian)(dian)(dian)(dian)(dian)壓(ya)零增量等）、溫(wen)度控(kong)制（包(bao)括最(zui)高溫(wen)度、最(zui)高溫(wen)升、溫(wen)度變化率等）、電(dian)(dian)(dian)(dian)(dian)流(liu)控(kong)制（包(bao)含最(zui)小電(dian)(dian)(dian)(dian)(dian)流(liu)、電(dian)(dian)(dian)(dian)(dian)流(liu)變化量等）、動態(tai)內(nei)阻控(kong)制等。
在(zai)實際應用中(zhong)，如(ru)果(guo)以單一的(de)(de)控制的(de)(de)方式都(dou)將不可(ke)避免地存(cun)在(zai)缺陷(xian)。比如(ru)，在(zai)恒(heng)壓(ya)(ya)均(jun)(jun)衡充電(dian)(dian)(dian)(dian)過程(cheng)中(zhong)，電(dian)(dian)(dian)(dian)壓(ya)(ya)保持恒(heng)定(ding)，電(dian)(dian)(dian)(dian)流(liu)(liu)會隨著充電(dian)(dian)(dian)(dian)的(de)(de)進(jin)程(cheng)逐漸減小(xiao)(xiao)，當小(xiao)(xiao)到一定(ding)程(cheng)度(du)電(dian)(dian)(dian)(dian)流(liu)(liu)將會恒(heng)定(ding)，不再下(xia)降，這時的(de)(de)電(dian)(dian)(dian)(dian)能(neng)(neng)向化(hua)學能(neng)(neng)的(de)(de)轉化(hua)效(xiao)率(lv)已(yi)經很低，電(dian)(dian)(dian)(dian)能(neng)(neng)主要用于電(dian)(dian)(dian)(dian)解水，一般認為(wei)(wei)這個(ge)電(dian)(dian)(dian)(dian)流(liu)(liu)為(wei)(wei)蓄(xu)電(dian)(dian)(dian)(dian)池恒(heng)壓(ya)(ya)均(jun)(jun)衡充電(dian)(dian)(dian)(dian)的(de)(de)殘(can)余(yu)電(dian)(dian)(dian)(dian)流(liu)(liu)。然(ran)而，殘(can)余(yu)電(dian)(dian)(dian)(dian)流(liu)(liu)的(de)(de)大小(xiao)(xiao)將隨著環境溫(wen)度(du)的(de)(de)變化(hua)而變化(hua)，也(ye)就是說殘(can)余(yu)電(dian)(dian)(dian)(dian)流(liu)(liu)是一個(ge)受內(nei)、外(wai)界多重因素(su)影響的(de)(de)動態值。若沒有溫(wen)度(du)控制，最高充電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓(ya)(ya)和切(qie)換電(dian)(dian)(dian)(dian)流(liu)(liu)都(dou)只能(neng)(neng)設置(zhi)成(cheng)定(ding)值，而這個(ge)定(ding)值無論如(ru)何設置(zhi)，都(dou)只能(neng)(neng)在(zai)一個(ge)相對(dui)較小(xiao)(xiao)的(de)(de)范圍(wei)內(nei)成(cheng)為(wei)(wei)最佳設置(zhi)。為(wei)(wei)此，設計的(de)(de)充電(dian)(dian)(dian)(dian)器通(tong)過對(dui)電(dian)(dian)(dian)(dian)壓(ya)(ya)、電(dian)(dian)(dian)(dian)流(liu)(liu)、溫(wen)度(du)等工作(zuo)參(can)(can)數進(jin)行實時檢測(ce)，并按模糊理論的(de)(de)評判規則對(dui)這些參(can)(can)數進(jin)行綜合分析，從而確定(ding)蓄(xu)電(dian)(dian)(dian)(dian)池是否(fou)充滿。
2. 3 軟件架構
P IC16C712單片(pian)(pian)機(ji)的軟件模塊(kuai)主要完成對傳感器的輸(shu)入(ru)信號(hao)進(jin)行采(cai)集、對電(dian)(dian)源專(zhuan)用芯片(pian)(pian)UC3875進(jin)行控制(zhi)、對異(yi)(yi)常(chang)進(jin)行處理等工作。在設計過程中，軟件系(xi)統每(mei)隔(ge)10 s檢測(ce)一次電(dian)(dian)壓和電(dian)(dian)流(liu)； 每(mei)隔(ge)20 s檢測(ce)一次溫(wen)度(du)。如(ru)有異(yi)(yi)常(chang)，系(xi)統將通過LED提示用戶(hu)出現何種(zhong)異(yi)(yi)常(chang)并采(cai)取相(xiang)應的保護措施。整個系(xi)統的軟件架構，如(ru)圖5所(suo)示。
圖5 軟件架構
對充(chong)(chong)電(dian)器樣(yang)機進行的測試表明(ming)蓄電(dian)池充(chong)(chong)電(dian)器具有如下(xia)特性：
（1）輸入電壓： 220 Vac;
（2）輸出(chu)電(dian)壓： 40~60V;
（3）輸出電流(liu)： < 10A;
（4）功(gong)率因數(shu)： > 0. 99;
（5）充(chong)電(dian)噪(zao)聲： < 20dB;
（6）充電(dian)時間(jian)： 6~8h;
（7）充電效(xiao)率(lv)： > 85%;
（8）充電溫升： < 15℃；
（9）質(zhi) 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，充電器自動(dong)切(qie)斷主電路，同時點亮相應的LED故障(zhang)指示燈(deng)指示故障(zhang)原因，具有(you)良(liang)好的保護(hu)特性。