隨著(zhu)油價的(de)(de)(de)不斷上漲和(he)人們環保意識的(de)(de)(de)增強，電(dian)(dian)(dian)(dian)動自行(xing)車(che)以其價格(ge)低、綠色環保，使(shi)(shi)(shi)(shi)用安全方(fang)便等優點越(yue)來越(yue)受到消費者的(de)(de)(de)喜愛。評(ping)價電(dian)(dian)(dian)(dian)動自行(xing)車(che)質(zhi)量(liang)好壞(huai)的(de)(de)(de)重要參數之一是(shi)其蓄(xu)(xu)電(dian)(dian)(dian)(dian)池的(de)(de)(de)使(shi)(shi)(shi)(shi)用壽命(ming)。而蓄(xu)(xu)電(dian)(dian)(dian)(dian)池的(de)(de)(de)充電(dian)(dian)(dian)(dian)過程對其壽命(ming)影響(xiang)最大(da)。研(yan)究表明：過充電(dian)(dian)(dian)(dian)，可(ke)使(shi)(shi)(shi)(shi)蓄(xu)(xu)電(dian)(dian)(dian)(dian)池發熱(re)，電(dian)(dian)(dian)(dian)解液失水；而充電(dian)(dian)(dian)(dian)不足(zu)，則(ze)可(ke)使(shi)(shi)(shi)(shi)蓄(xu)(xu)電(dian)(dian)(dian)(dian)池內(nei)化學反應不充分(fen)，長期充電(dian)(dian)(dian)(dian)不足(zu)會導(dao)致蓄(xu)(xu)電(dian)(dian)(dian)(dian)池容量(liang)下降(jiang)。由此(ci)可(ke)見，充電(dian)(dian)(dian)(dian)器性能(neng)的(de)(de)(de)好壞(huai)直接影響(xiang)著(zhu)蓄(xu)(xu)電(dian)(dian)(dian)(dian)池的(de)(de)(de)使(shi)(shi)(shi)(shi)用效(xiao)果和(he)使(shi)(shi)(shi)(shi)用壽命(ming)。

  目前市場上的充電器存在的主要不足，第一不是從副邊繞組直接獲得取樣信號，因而穩壓效果不理想；第二是輸出電流和電壓調節范圍窄，因而只適用于固定負載。為此，本文介紹了一種以單片機為控制器的通用智能充電器的設(she)計方案(an)。該裝置能根據蓄電(dian)池的充(chong)(chong)電(dian)特性或實時監測到的充(chong)(chong)電(dian)狀態，來智能化地調(diao)節(jie)充(chong)(chong)電(dian)電(dian)壓和(he)(he)充(chong)(chong)電(dian)電(dian)流(liu)，而且(qie)調(diao)節(jie)范圍(wei)寬(kuan)(kuan)，并具有過(guo)流(liu)、過(guo)壓、過(guo)溫等(deng)保護功(gong)能。 1、系(xi)統結構 該系(xi)統主(zhu)要由電(dian)源變換電(dian)路、采樣電(dian)路、微處(chu)理(li)器，脈寬(kuan)(kuan)調(diao)制器、鍵(jian)盤(pan)、顯示器和(he)(he)溫度傳感器等(deng)部分組成，是一個閉環的智能充(chong)(chong)電(dian)系(xi)統。

   2、硬件電路 本智能充電器的硬(ying)件(jian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)分為(wei)(wei)(wei)(wei)開(kai)關(guan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)部分、以單(dan)(dan)片(pian)機(ji)為(wei)(wei)(wei)(wei)主(zhu)(zhu)的控(kong)制(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)和(he)以UC3842為(wei)(wei)(wei)(wei)核心的脈寬調制(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)三部分。 2．1開(kai)關(guan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)設(she)計(ji) 本設(she)計(ji)采用電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)控(kong)制(zhi)型脈寬調制(zhi)方式。其整(zheng)個(ge)工作過(guo)程(cheng)是將交流(liu)(liu)輸入經(jing)濾(lv)波、整(zheng)流(liu)(liu)后變為(wei)(wei)(wei)(wei)直(zhi)流(liu)(liu)高(gao)(gao)壓(ya)，再由開(kai)關(guan)管斬(zhan)波、高(gao)(gao)頻變壓(ya)器(qi)(qi)(qi)降(jiang)壓(ya)后得到高(gao)(gao)頻矩形電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)，最(zui)后經(jing)過(guo)輸出(chu)整(zheng)流(liu)(liu)濾(lv)波獲得所(suo)需要的直(zhi)流(liu)(liu)輸出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)。系統(tong)對(dui)開(kai)關(guan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)的要求是其交流(liu)(liu)輸入電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)范圍為(wei)(wei)(wei)(wei)90～270 V，能同時(shi)輸出(chu)+5V作為(wei)(wei)(wei)(wei)控(kong)制(zhi)部分電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)及(ji)12～60 V主(zhu)(zhu)回路(lu)(lu)的電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)。輸出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)為(wei)(wei)(wei)(wei)1～3 A。 2．2單(dan)(dan)片(pian)機(ji)控(kong)制(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)設(she)計(ji) 單(dan)(dan)片(pian)機(ji)控(kong)制(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)主(zhu)(zhu)要由單(dan)(dan)片(pian)機(ji)AT89S52、ADCTLC0832、多路(lu)(lu)選擇(ze)開(kai)關(guan)CD4051、數(shu)字電(dian)(dian)(dian)(dian)(dian)(dian)(dian)位器(qi)(qi)(qi)X9C102、數(shu)字溫度傳感器(qi)(qi)(qi)DSl8820、取(qu)樣(yang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻Rs和(he)Rw、2×4鍵盤、液晶顯示CONl6等(deng)組成(cheng)。

    本部分設(she)(she)計時(shi)(shi)(shi)應先(xian)根據蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)(de)型號參數，來通(tong)(tong)過(guo)鍵(jian)盤設(she)(she)計與(yu)之對(dui)(dui)應的(de)(de)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)、充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)以(yi)及(ji)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)(shi)(shi)間，當電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路接(jie)上蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)后(hou)(hou)，充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)過(guo)程開始(shi)，此后(hou)(hou)由(you)單(dan)片機(ji)(ji)通(tong)(tong)過(guo)取(qu)樣(yang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)RM檢(jian)測(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，若(ruo)檢(jian)測(ce)(ce)到(dao)蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)因(yin)(yin)過(guo)渡放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)而(er)使(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)低于正常范圍(wei)。那(nei)么，為(wei)了避免充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)過(guo)大(da)而(er)造成蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)損(sun)壞，應先(xian)對(dui)(dui)蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)實(shi)行穩定(ding)(ding)的(de)(de)小(xiao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)本設(she)(she)計程序中設(she)(she)為(wei)l／5的(de)(de)設(she)(she)定(ding)(ding)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)，同(tong)時(shi)(shi)(shi)，單(dan)片機(ji)(ji)開始(shi)計時(shi)(shi)(shi)，之后(hou)(hou)單(dan)片機(ji)(ji)將不(bu)斷檢(jian)測(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)和充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)并顯示在(zai)液晶屏(ping)上，隨著充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)進行，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)不(bu)斷上升(sheng)，當上升(sheng)到(dao)正常范圍(wei)時(shi)(shi)(shi)，單(dan)片機(ji)(ji)可(ke)通(tong)(tong)過(guo)控制數字電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)位器來調節輸出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，從(cong)而(er)轉入大(da)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)恒流(liu)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)即(ji)設(she)(she)定(ding)(ding)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)方式，此后(hou)(hou)，單(dan)片機(ji)(ji)一(yi)直保(bao)持不(bu)停地檢(jian)測(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，當電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)達到(dao)設(she)(she)定(ding)(ding)值時(shi)(shi)(shi)，單(dan)片機(ji)(ji)發出(chu)指令，以(yi)增(zeng)大(da)數字電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)位器的(de)(de)阻(zu)值，并通(tong)(tong)過(guo)脈寬調制減(jian)小(xiao)輸出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)。從(cong)而(er)使(shi)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)減(jian)小(xiao)，當充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)減(jian)小(xiao)到(dao)1／5的(de)(de)設(she)(she)定(ding)(ding)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)時(shi)(shi)(shi)，再轉為(wei)涓流(liu)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，最后(hou)(hou)在(zai)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)(shi)(shi)間到(dao)時(shi)(shi)(shi)關閉電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)，這樣(yang)就避免了因(yin)(yin)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)溫升(sheng)過(guo)快或嚴重極化而(er)影(ying)響(xiang)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)質量，提高(gao)(gao)蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)(de)使(shi)用(yong)壽命。當檢(jian)測(ce)(ce)到(dao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)、充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)和溫度(du)超過(guo)設(she)(she)定(ding)(ding)值的(de)(de)1／10倍時(shi)(shi)(shi)由(you)程序設(she)(she)定(ding)(ding)，單(dan)片機(ji)(ji)立即(ji)輸出(chu)報警(jing)信(xin)號報警(jing)。同(tong)時(shi)(shi)(shi)使(shi)繼電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器動(dong)作并切(qie)斷總電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)，以(yi)提高(gao)(gao)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)安全性和可(ke)靠性。

   顯示(shi)器可用于顯示(shi)單(dan)片機(ji)實時(shi)采樣(yang)到的(de)(de)蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)、充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)、已充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)間和蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池的(de)(de)溫度，鍵(jian)盤則用于設定充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極限(xian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)、恒流(liu)(liu)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)極限(xian)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)和充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)間。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路中的(de)(de)單(dan)片機(ji)可通(tong)過串(chuan)口(kou)RS232和上位(wei)機(ji)相連(lian)，以用于存(cun)儲數(shu)(shu)據和虛擬顯示(shi)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)參數(shu)(shu)的(de)(de)設定。當檢測到充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)為(wei)零時(shi)，單(dan)片機(ji)轉入(ru)休眠(mian)狀態(tai)。而當檢測到充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)不為(wei)零時(shi)，單(dan)片機(ji)被激(ji)活(huo)。

   2．3 PWM控制器設計 PW M控制器部分是以UC3842為核心。UC3842芯片內含有5.0 V基準電壓穩壓器、高增益誤差放大器和脈沖寬度比較器，它可以控制芯片內的驅動器。而驅動器則可提供25 mA的輸出電流．可直接驅動NOSFET調整管，從而調整充電器的輸出電(dian)壓(ya)和電(dian)流。由于該驅動(dong)器同時具有過流、過壓(ya)保(bao)護，工作電(dian)源電(dian)壓(ya)可以在8～40 V，而啟(qi)動(dong)電(dian)流小于1 mA，工作溫(wen)度為O～70℃，因而是(shi)目(mu)前較理想的新型脈寬(kuan)調制(zhi)器。 PWM控(kong)制(zhi)器在啟(qi)動(dong)時，是(shi)由R1、Rw。

   為(wei)UC3842提供(gong)啟動電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，待其工(gong)作后(hou)(hou)，其輔助繞(rao)組3、4端的(de)(de)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)經(jing)(jing)D1整流、C4、C5濾波(bo)、DW1穩壓(ya)(ya)(ya)(ya)后(hou)(hou)得到的(de)(de)16 V直流電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，一(yi)路(lu)加(jia)到UC38427的(de)(de)7腳為(wei)其供(gong)電(dian)(dian)(dian)，另一(yi)路(lu)經(jing)(jing)R3和(he)數字電(dian)(dian)(dian)位(wei)(wei)器(qi)X9C102分壓(ya)(ya)(ya)(ya)后(hou)(hou)加(jia)到UC3842的(de)(de)2腳。以(yi)作為(wei)脈(mo)寬調制的(de)(de)輸入(ru)信號。一(yi)般在這(zhe)類電(dian)(dian)(dian)源的(de)(de)設計(ji)中，輸出(chu)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)取(qu)樣可與(yu)UC3842的(de)(de)供(gong)電(dian)(dian)(dian)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)相連。為(wei)了(le)反映(ying)輸出(chu)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)變化，本設計(ji)沒有加(jia)穩壓(ya)(ya)(ya)(ya)管，但(dan)這(zhe)會使UC3842的(de)(de)工(gong)作電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)不穩，輸出(chu)諧(xie)波(bo)成分增(zeng)多，為(wei)了(le)克服此不足(zu)，本設計(ji)中UC3842的(de)(de)供(gong)電(dian)(dian)(dian)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)采用(yong)由3、4繞(rao)組端壓(ya)(ya)(ya)(ya)單獨整流、濾波(bo)、穩壓(ya)(ya)(ya)(ya)后(hou)(hou)，提供(gong)給UC3842芯片(pian)16 V的(de)(de)穩定電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)。充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)的(de)(de)調節是將電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)經(jing)(jing)外(wai)環電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)取(qu)樣電(dian)(dian)(dian)路(lu)R12、RM取(qu)樣，再經(jing)(jing)多路(lu)電(dian)(dian)(dian)子開關選擇、MD變換(huan)，單片(pian)機處理后(hou)(hou)，送入(ru)數字電(dian)(dian)(dian)位(wei)(wei)器(qi)，以(yi)控制數字電(dian)(dian)(dian)位(wei)(wei)器(qi)的(de)(de)有效電(dian)(dian)(dian)阻。

   從而間接控制UC3842的2腳電壓，進而控制脈沖占空比，以改變充電電壓。 充電器輸出電(dian)(dian)壓(ya)偏(pian)高時，反(fan)饋回UC3842的(de)(de)2腳電(dian)(dian)壓(ya)也升高超過(guo)參考電(dian)(dian)壓(ya)2.5 V之后(hou)，驅動信號的(de)(de)脈沖占(zhan)空比(bi)減小，使輸出電(dian)(dian)壓(ya)下降，從而達到穩壓(ya)的(de)(de)目的(de)(de)。充電(dian)(dian)電(dian)(dian)流的(de)(de)調(diao)(diao)節(jie)主要(yao)是(shi)先將充電(dian)(dian)電(dian)(dian)流經外環電(dian)(dian)流取樣(yang)電(dian)(dian)阻Rs取樣(yang)和(he)LM358放大(da)可用R1調(diao)(diao)節(jie)放大(da)倍數(shu)、多路電(dian)(dian)子開(kai)關選擇、MD變換，再送單片機處(chu)理(li)，然后(hou)調(diao)(diao)節(jie)數(shu)字電(dian)(dian)位器的(de)(de)阻值。其調(diao)(diao)節(jie)過(guo)程與電(dian)(dian)壓(ya)調(diao)(diao)節(jie)相似，實際上，電(dian)(dian)流調(diao)(diao)節(jie)也是(shi)通過(guo)電(dian)(dian)壓(ya)調(diao)(diao)節(jie)實現的(de)(de)。

    2．4．保(bao)(bao)(bao)(bao)護(hu)(hu)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)設計 當(dang)(dang)過(guo)流(liu)或短路(lu)(lu)時(shi)，內(nei)環取(qu)(qu)樣(yang)(yang)電(dian)(dian)(dian)(dian)(dian)阻(zu)R10兩端的電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)升高。當(dang)(dang)3腳(jiao)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)超(chao)過(guo)1伏時(shi)，通(tong)過(guo)UC3842的內(nei)部調(diao)(diao)(diao)(diao)制(zhi)可使其停(ting)止(zhi)脈寬輸出，開關管截止(zhi)，輸出電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)和(he)電(dian)(dian)(dian)(dian)(dian)流(liu)均為(wei)0，從而保(bao)(bao)(bao)(bao)護(hu)(hu)電(dian)(dian)(dian)(dian)(dian)源。過(guo)壓(ya)(ya)(ya)(ya)(ya)時(shi)，DW1和(he)DW2會擊穿而短路(lu)(lu)，也會造成過(guo)流(liu)保(bao)(bao)(bao)(bao)護(hu)(hu)，DW2可用以(yi)保(bao)(bao)(bao)(bao)護(hu)(hu)場效應管和(he)UC3842。而當(dang)(dang)發(fa)生欠壓(ya)(ya)(ya)(ya)(ya)時(shi)，即當(dang)(dang)UC3842的7腳(jiao)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)降至10 V以(yi)下時(shi)，UC3842將啟動欠壓(ya)(ya)(ya)(ya)(ya)鎖(suo)定電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)而關閉開關控制(zhi)器。內(nei)環的這(zhe)種(zhong)反饋調(diao)(diao)(diao)(diao)整(zheng)是(shi)在輸出電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)尚未發(fa)生變(bian)化時(shi)，通(tong)過(guo)檢(jian)測內(nei)環電(dian)(dian)(dian)(dian)(dian)流(liu)使脈寬提前得到(dao)調(diao)(diao)(diao)(diao)整(zheng)，前饋控制(zhi)，從而加快了變(bian)換器對(dui)異(yi)常(chang)情況的動態響應速度。以(yi)便更(geng)加快速有效地起到(dao)保(bao)(bao)(bao)(bao)護(hu)(hu)作用。當(dang)(dang)然(ran)，外(wai)環電(dian)(dian)(dian)(dian)(dian)流(liu)、電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)的取(qu)(qu)樣(yang)(yang)Rs、Rw亦可通(tong)過(guo)單片機的調(diao)(diao)(diao)(diao)節作用來達到(dao)對(dui)異(yi)常(chang)情況的保(bao)(bao)(bao)(bao)護(hu)(hu)，但響應速度比內(nei)環慢5～10個(ge)工頻周期，因(yin)此，外(wai)環取(qu)(qu)樣(yang)(yang)主(zhu)要是(shi)調(diao)(diao)(diao)(diao)節充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)和(he)充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)，兼作二次保(bao)(bao)(bao)(bao)護(hu)(hu)，而內(nei)環取(qu)(qu)樣(yang)(yang)則是(shi)主(zhu)要的，它是(shi)一次的保(bao)(bao)(bao)(bao)護(hu)(hu)，這(zhe)種(zhong)雙環保(bao)(bao)(bao)(bao)護(hu)(hu)方式會更(geng)加安(an)全可靠。

    3、軟件設(she)計 在(zai)程(cheng)序(xu)的(de)(de)初始階段，首先是對單片機進行初始化，即(ji)根據不同(tong)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)設(she)定不同(tong)的(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)參數(shu)，選擇(ze)不同(tong)的(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)策略(lve)。其(qi)后是判(pan)斷(duan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)是否連(lian)接正確，根據電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)值判(pan)斷(duan)應(ying)該進入(ru)哪一(yi)個充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)階段即(ji)小(xiao)(xiao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)預充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，大(da)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)恒(heng)流(liu)(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)或恒(heng)壓(ya)涓流(liu)(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)方式。在(zai)預充(chong)(chong)階段，應(ying)降低充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)，而在(zai)恒(heng)流(liu)(liu)(liu)方式時，應(ying)不斷(duan)檢測充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)是否達到恒(heng)定電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)如1.8 A，如果小(xiao)(xiao)于1.8 A，則抬高電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)兩端(duan)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)，使之達到1.8 A，以上調節過(guo)程(cheng)均可采用比例控制。在(zai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)兩端(duan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)達到設(she)定值后，系統再進入(ru)涓流(liu)(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)模式。該充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器(qi)的(de)(de)程(cheng)序(xu)流(liu)(liu)(liu)程(cheng)如圖(tu)3所示。圖(tu)3中(zhong)，Is為(wei)設(she)定的(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)即(ji)恒(heng)流(liu)(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)，Umin為(wei)蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)限電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)，Umax為(wei)蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)限電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)。

   應用試驗 本設計選用了電動自行車常用的36 V／12 Ah鉛酸蓄電池作為測試對象，其恒壓充電電壓設定為43 V，恒流充電電流Is為1.8 A，起始時，隨著充電的進行，充電電流幾乎維持1.8 A不變，但電池電壓不斷升高，當充電3小時后。電壓上升減慢；當充電到4小時后，充電電壓接近43 V；之后電壓上升更加緩慢。而且充電下降較快。當充到43 V時，充電器自(zi)動停止。從測(ce)試(shi)數(shu)據來看，該設(she)(she)計(ji)達(da)到了恒流快(kuai)充(chong)(chong)(chong)(chong)(chong)，恒壓(ya)涓(juan)充(chong)(chong)(chong)(chong)(chong)，充(chong)(chong)(chong)(chong)(chong)滿自(zi)行(xing)關斷的(de)(de)(de)設(she)(she)計(ji)要求。 5、結束語(yu) 本文設(she)(she)計(ji)的(de)(de)(de)過(guo)(guo)(guo)度(du)放(fang)電(dian)(dian)(dian)(dian)(dian)預(yu)充(chong)(chong)(chong)(chong)(chong)、恒流快(kuai)充(chong)(chong)(chong)(chong)(chong)、恒壓(ya)涓(juan)充(chong)(chong)(chong)(chong)(chong)、智能控制(zhi)的(de)(de)(de)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)方案(an)，能很好地(di)解決電(dian)(dian)(dian)(dian)(dian)動自(zi)行(xing)車用(yong)電(dian)(dian)(dian)(dian)(dian)池(chi)在充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)過(guo)(guo)(guo)程中存在的(de)(de)(de)過(guo)(guo)(guo)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)、充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)不足和(he)發熱(re)等(deng)問題，并能根(gen)據不同(tong)電(dian)(dian)(dian)(dian)(dian)池(chi)選擇不同(tong)的(de)(de)(de)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)方案(an)。而且具有(you)通用(yong)性。能實時檢(jian)測(ce)并顯示(shi)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流、充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)壓(ya)、充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)時間和(he)蓄電(dian)(dian)(dian)(dian)(dian)池(chi)溫度(du)等(deng)參數(shu)。由于電(dian)(dian)(dian)(dian)(dian)路具有(you)內外環控制(zhi)，符(fu)合最(zui)(zui)優控制(zhi)規律。最(zui)(zui)具有(you)過(guo)(guo)(guo)流、過(guo)(guo)(guo)壓(ya)和(he)超溫保護功能，同(tong)時由于

   UC3842采用(yong)穩壓供電，因此，不(bu)但諧波污染(ran)程度(du)低，原副邊電氣(qi)隔離安全(quan)可(ke)靠(kao)，同時還可(ke)根據(ju)負載情況通(tong)過單片機來進行控(kong)制(zhi)，并可(ke)實現跳周期模式工作(zuo)。故可(ke)提高電源的效率(lv)。