隨著油價的(de)(de)不斷上(shang)漲(zhang)和人們(men)環(huan)保意(yi)識的(de)(de)增(zeng)強，電(dian)動(dong)自(zi)行車以其價格低、綠色環(huan)保，使用(yong)(yong)安全方便等優點越來越受到消(xiao)費者(zhe)的(de)(de)喜愛。評價電(dian)動(dong)自(zi)行車質量好壞(huai)的(de)(de)重要參數之一是其蓄電(dian)池(chi)的(de)(de)使用(yong)(yong)壽命(ming)。而蓄電(dian)池(chi)的(de)(de)充(chong)電(dian)過(guo)程對其壽命(ming)影(ying)響(xiang)最大。研究(jiu)表明：過(guo)充(chong)電(dian)，可(ke)使蓄電(dian)池(chi)發(fa)熱，電(dian)解液(ye)失(shi)水；而充(chong)電(dian)不足，則(ze)可(ke)使蓄電(dian)池(chi)內化(hua)學(xue)反應不充(chong)分，長期充(chong)電(dian)不足會導致蓄電(dian)池(chi)容(rong)量下(xia)降。由(you)此可(ke)見(jian)，充(chong)電(dian)器性能的(de)(de)好壞(huai)直接(jie)影(ying)響(xiang)著蓄電(dian)池(chi)的(de)(de)使用(yong)(yong)效果和使用(yong)(yong)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(de)設(she)計方案。該(gai)裝置能(neng)根據蓄電(dian)(dian)(dian)池的(de)充(chong)電(dian)(dian)(dian)特性或實時(shi)監測到(dao)的(de)充(chong)電(dian)(dian)(dian)狀態，來智(zhi)能(neng)化地(di)調(diao)(diao)節充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)壓和(he)充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)，而(er)且調(diao)(diao)節范圍寬，并具有過流(liu)、過壓、過溫等保護(hu)功能(neng)。 1、系(xi)統結(jie)構 該(gai)系(xi)統主(zhu)要由(you)電(dian)(dian)(dian)源變換電(dian)(dian)(dian)路、采樣電(dian)(dian)(dian)路、微處理器，脈寬調(diao)(diao)制器、鍵盤、顯示(shi)器和(he)溫度傳感器等部分組成，是(shi)一個閉(bi)環的(de)智(zhi)能(neng)充(chong)電(dian)(dian)(dian)系(xi)統。

   2、硬件電路 本智能充電器的硬件電路(lu)分為開關(guan)電源(yuan)(yuan)部分、以單(dan)片(pian)(pian)機為主的控(kong)(kong)制(zhi)電路(lu)和以UC3842為核心的脈寬(kuan)調(diao)制(zhi)電路(lu)三部分。 2．1開關(guan)電源(yuan)(yuan)設計(ji)(ji) 本設計(ji)(ji)采用電流(liu)(liu)(liu)(liu)控(kong)(kong)制(zhi)型脈寬(kuan)調(diao)制(zhi)方(fang)式。其(qi)整個工作(zuo)過(guo)(guo)程是將(jiang)交(jiao)流(liu)(liu)(liu)(liu)輸(shu)入經濾(lv)波、整流(liu)(liu)(liu)(liu)后變(bian)(bian)為直(zhi)流(liu)(liu)(liu)(liu)高(gao)壓(ya)(ya)，再由開關(guan)管斬波、高(gao)頻變(bian)(bian)壓(ya)(ya)器(qi)降壓(ya)(ya)后得到(dao)高(gao)頻矩形電壓(ya)(ya)，最(zui)后經過(guo)(guo)輸(shu)出(chu)整流(liu)(liu)(liu)(liu)濾(lv)波獲得所需(xu)要(yao)的直(zhi)流(liu)(liu)(liu)(liu)輸(shu)出(chu)電壓(ya)(ya)。系(xi)統對開關(guan)電源(yuan)(yuan)的要(yao)求是其(qi)交(jiao)流(liu)(liu)(liu)(liu)輸(shu)入電壓(ya)(ya)范圍為90～270 V，能同(tong)時輸(shu)出(chu)+5V作(zuo)為控(kong)(kong)制(zhi)部分電源(yuan)(yuan)及(ji)12～60 V主回路(lu)的電壓(ya)(ya)。輸(shu)出(chu)電流(liu)(liu)(liu)(liu)為1～3 A。 2．2單(dan)片(pian)(pian)機控(kong)(kong)制(zhi)電路(lu)設計(ji)(ji) 單(dan)片(pian)(pian)機控(kong)(kong)制(zhi)電路(lu)主要(yao)由單(dan)片(pian)(pian)機AT89S52、ADCTLC0832、多(duo)路(lu)選擇開關(guan)CD4051、數字電位器(qi)X9C102、數字溫(wen)度(du)傳感器(qi)DSl8820、取樣電阻Rs和Rw、2×4鍵盤(pan)、液晶(jing)顯示CONl6等(deng)組成。

    本部分設(she)(she)計時(shi)(shi)(shi)應(ying)先根(gen)據蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)(de)型號(hao)(hao)參(can)數，來(lai)通(tong)(tong)過(guo)鍵盤設(she)(she)計與之(zhi)對應(ying)的(de)(de)(de)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)、充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)以及(ji)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)(shi)(shi)間，當電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路接(jie)上(shang)蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)后，充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)過(guo)程(cheng)開始，此(ci)后由單片(pian)(pian)(pian)機通(tong)(tong)過(guo)取樣(yang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻RM檢測(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)，若檢測(ce)到(dao)(dao)(dao)蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)因過(guo)渡放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)而(er)使(shi)(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)低于正常范(fan)圍(wei)。那么，為(wei)了避免(mian)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)過(guo)大(da)而(er)造成蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)損壞(huai)，應(ying)先對蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)實行穩定(ding)(ding)的(de)(de)(de)小(xiao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)本設(she)(she)計程(cheng)序中設(she)(she)為(wei)l／5的(de)(de)(de)設(she)(she)定(ding)(ding)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)，同時(shi)(shi)(shi)，單片(pian)(pian)(pian)機開始計時(shi)(shi)(shi)，之(zhi)后單片(pian)(pian)(pian)機將不斷(duan)(duan)檢測(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)和充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)并(bing)(bing)顯示在(zai)液晶屏(ping)上(shang)，隨著(zhu)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)進行，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)不斷(duan)(duan)上(shang)升，當上(shang)升到(dao)(dao)(dao)正常范(fan)圍(wei)時(shi)(shi)(shi)，單片(pian)(pian)(pian)機可通(tong)(tong)過(guo)控制數字電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)位(wei)器來(lai)調(diao)節(jie)輸(shu)出(chu)(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)，從而(er)轉入大(da)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)恒流(liu)(liu)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)即(ji)(ji)設(she)(she)定(ding)(ding)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)方式，此(ci)后，單片(pian)(pian)(pian)機一直保持不停地檢測(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)，當電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)達到(dao)(dao)(dao)設(she)(she)定(ding)(ding)值(zhi)時(shi)(shi)(shi)，單片(pian)(pian)(pian)機發出(chu)(chu)指令，以增(zeng)大(da)數字電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)位(wei)器的(de)(de)(de)阻值(zhi)，并(bing)(bing)通(tong)(tong)過(guo)脈寬調(diao)制減(jian)小(xiao)輸(shu)出(chu)(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)。從而(er)使(shi)(shi)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)減(jian)小(xiao)，當充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)減(jian)小(xiao)到(dao)(dao)(dao)1／5的(de)(de)(de)設(she)(she)定(ding)(ding)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)時(shi)(shi)(shi)，再轉為(wei)涓(juan)流(liu)(liu)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，最后在(zai)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)(shi)(shi)間到(dao)(dao)(dao)時(shi)(shi)(shi)關閉(bi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源，這樣(yang)就避免(mian)了因電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)溫升過(guo)快或嚴重極化(hua)而(er)影響(xiang)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)質(zhi)量，提高(gao)蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)(de)使(shi)(shi)用壽命。當檢測(ce)到(dao)(dao)(dao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)、充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)和溫度超過(guo)設(she)(she)定(ding)(ding)值(zhi)的(de)(de)(de)1／10倍時(shi)(shi)(shi)由程(cheng)序設(she)(she)定(ding)(ding)，單片(pian)(pian)(pian)機立(li)即(ji)(ji)輸(shu)出(chu)(chu)報警(jing)信(xin)號(hao)(hao)報警(jing)。同時(shi)(shi)(shi)使(shi)(shi)繼(ji)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器動作并(bing)(bing)切斷(duan)(duan)總電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源，以提高(gao)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)安全性和可靠性。

   顯示器可(ke)用(yong)于顯示單(dan)片(pian)機(ji)實(shi)時(shi)采(cai)樣到的(de)(de)蓄(xu)電(dian)(dian)池電(dian)(dian)壓、充(chong)電(dian)(dian)電(dian)(dian)流、已(yi)充(chong)電(dian)(dian)時(shi)間和蓄(xu)電(dian)(dian)池的(de)(de)溫(wen)度，鍵(jian)盤則用(yong)于設定充(chong)電(dian)(dian)電(dian)(dian)壓充(chong)電(dian)(dian)極限電(dian)(dian)壓、恒(heng)流充(chong)電(dian)(dian)電(dian)(dian)流極限充(chong)電(dian)(dian)電(dian)(dian)流和充(chong)電(dian)(dian)時(shi)間。電(dian)(dian)路(lu)中的(de)(de)單(dan)片(pian)機(ji)可(ke)通過串口RS232和上位機(ji)相連，以用(yong)于存儲數據和虛(xu)擬(ni)顯示充(chong)電(dian)(dian)參數的(de)(de)設定。當檢(jian)測到充(chong)電(dian)(dian)電(dian)(dian)流為零(ling)時(shi)，單(dan)片(pian)機(ji)轉入(ru)休眠狀態。而(er)當檢(jian)測到充(chong)電(dian)(dian)電(dian)(dian)流不(bu)為零(ling)時(shi)，單(dan)片(pian)機(ji)被激活(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(de)輸(shu)出電(dian)壓(ya)(ya)和電(dian)流。由(you)于(yu)該驅(qu)動器同時(shi)具有過流、過壓(ya)(ya)保護，工(gong)作(zuo)電(dian)源電(dian)壓(ya)(ya)可以在8～40 V，而(er)啟(qi)動電(dian)流小于(yu)1 mA，工(gong)作(zuo)溫度為O～70℃，因而(er)是目前較(jiao)理想的(de)新型(xing)脈(mo)寬調制(zhi)器。 PWM控制(zhi)器在啟(qi)動時(shi)，是由(you)R1、Rw。

   為UC3842提供啟動電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，待其(qi)工作后，其(qi)輔助繞(rao)組(zu)3、4端的(de)(de)(de)(de)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)經D1整流(liu)、C4、C5濾波、DW1穩(wen)壓(ya)(ya)(ya)(ya)后得到(dao)(dao)的(de)(de)(de)(de)16 V直(zhi)流(liu)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，一路(lu)加(jia)(jia)到(dao)(dao)UC38427的(de)(de)(de)(de)7腳為其(qi)供電(dian)(dian)(dian)，另一路(lu)經R3和數(shu)字(zi)電(dian)(dian)(dian)位器(qi)X9C102分壓(ya)(ya)(ya)(ya)后加(jia)(jia)到(dao)(dao)UC3842的(de)(de)(de)(de)2腳。以(yi)作為脈寬調制的(de)(de)(de)(de)輸入(ru)信(xin)號(hao)。一般在這(zhe)類(lei)電(dian)(dian)(dian)源的(de)(de)(de)(de)設(she)計中(zhong)，輸出電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)取(qu)樣可與UC3842的(de)(de)(de)(de)供電(dian)(dian)(dian)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)相連(lian)。為了(le)反映輸出電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)變(bian)化，本(ben)設(she)計沒有加(jia)(jia)穩(wen)壓(ya)(ya)(ya)(ya)管，但這(zhe)會(hui)使UC3842的(de)(de)(de)(de)工作電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)不(bu)(bu)穩(wen)，輸出諧波成分增多，為了(le)克服此(ci)不(bu)(bu)足(zu)，本(ben)設(she)計中(zhong)UC3842的(de)(de)(de)(de)供電(dian)(dian)(dian)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)采用由3、4繞(rao)組(zu)端壓(ya)(ya)(ya)(ya)單獨整流(liu)、濾波、穩(wen)壓(ya)(ya)(ya)(ya)后，提供給UC3842芯片(pian)16 V的(de)(de)(de)(de)穩(wen)定電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)。充電(dian)(dian)(dian)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)的(de)(de)(de)(de)調節是(shi)將電(dian)(dian)(dian)池電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)經外環電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)取(qu)樣電(dian)(dian)(dian)路(lu)R12、RM取(qu)樣，再(zai)經多路(lu)電(dian)(dian)(dian)子(zi)開(kai)關選擇、MD變(bian)換，單片(pian)機處理后，送入(ru)數(shu)字(zi)電(dian)(dian)(dian)位器(qi)，以(yi)控(kong)制數(shu)字(zi)電(dian)(dian)(dian)位器(qi)的(de)(de)(de)(de)有效(xiao)電(dian)(dian)(dian)阻(zu)。

   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(chu)(chu)電(dian)(dian)(dian)(dian)壓(ya)偏高(gao)時，反(fan)饋回UC3842的(de)(de)(de)2腳電(dian)(dian)(dian)(dian)壓(ya)也升高(gao)超過(guo)參考電(dian)(dian)(dian)(dian)壓(ya)2.5 V之(zhi)后，驅(qu)動信(xin)號的(de)(de)(de)脈沖占空比減(jian)小，使輸出(chu)(chu)電(dian)(dian)(dian)(dian)壓(ya)下(xia)降，從而達(da)到(dao)穩壓(ya)的(de)(de)(de)目的(de)(de)(de)。充電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流的(de)(de)(de)調(diao)(diao)節(jie)(jie)主要(yao)是先將充電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流經外(wai)環電(dian)(dian)(dian)(dian)流取樣電(dian)(dian)(dian)(dian)阻Rs取樣和LM358放(fang)大可(ke)用R1調(diao)(diao)節(jie)(jie)放(fang)大倍數(shu)、多路電(dian)(dian)(dian)(dian)子(zi)開關選(xuan)擇、MD變換(huan)，再送單片機(ji)處理，然后調(diao)(diao)節(jie)(jie)數(shu)字電(dian)(dian)(dian)(dian)位(wei)器的(de)(de)(de)阻值。其調(diao)(diao)節(jie)(jie)過(guo)程(cheng)與(yu)電(dian)(dian)(dian)(dian)壓(ya)調(diao)(diao)節(jie)(jie)相(xiang)似，實際上，電(dian)(dian)(dian)(dian)流調(diao)(diao)節(jie)(jie)也是通過(guo)電(dian)(dian)(dian)(dian)壓(ya)調(diao)(diao)節(jie)(jie)實現的(de)(de)(de)。

    2．4．保(bao)(bao)護(hu)(hu)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)設計 當過流或短(duan)路(lu)(lu)時(shi)(shi)，內(nei)(nei)(nei)(nei)(nei)環(huan)取(qu)樣電(dian)(dian)(dian)(dian)(dian)阻R10兩端的(de)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)升高。當3腳電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)超過1伏時(shi)(shi)，通過UC3842的(de)內(nei)(nei)(nei)(nei)(nei)部調(diao)(diao)制(zhi)(zhi)可使其停止(zhi)脈寬輸出，開(kai)關(guan)(guan)管(guan)截止(zhi)，輸出電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)和(he)電(dian)(dian)(dian)(dian)(dian)流均為0，從(cong)而(er)(er)(er)保(bao)(bao)護(hu)(hu)電(dian)(dian)(dian)(dian)(dian)源。過壓(ya)(ya)時(shi)(shi)，DW1和(he)DW2會(hui)擊穿而(er)(er)(er)短(duan)路(lu)(lu)，也(ye)會(hui)造成過流保(bao)(bao)護(hu)(hu)，DW2可用(yong)(yong)以保(bao)(bao)護(hu)(hu)場(chang)效(xiao)應管(guan)和(he)UC3842。而(er)(er)(er)當發(fa)生(sheng)欠壓(ya)(ya)時(shi)(shi)，即當UC3842的(de)7腳電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)降至(zhi)10 V以下時(shi)(shi)，UC3842將啟動欠壓(ya)(ya)鎖定電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)而(er)(er)(er)關(guan)(guan)閉開(kai)關(guan)(guan)控(kong)制(zhi)(zhi)器。內(nei)(nei)(nei)(nei)(nei)環(huan)的(de)這種反饋(kui)調(diao)(diao)整是在(zai)輸出電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)尚未發(fa)生(sheng)變(bian)化(hua)時(shi)(shi)，通過檢測(ce)內(nei)(nei)(nei)(nei)(nei)環(huan)電(dian)(dian)(dian)(dian)(dian)流使脈寬提前得到調(diao)(diao)整，前饋(kui)控(kong)制(zhi)(zhi)，從(cong)而(er)(er)(er)加快了變(bian)換器對異(yi)常情(qing)況(kuang)的(de)動態響應速度(du)。以便更加快速有效(xiao)地起到保(bao)(bao)護(hu)(hu)作用(yong)(yong)。當然，外(wai)環(huan)電(dian)(dian)(dian)(dian)(dian)流、電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)的(de)取(qu)樣Rs、Rw亦可通過單片機的(de)調(diao)(diao)節作用(yong)(yong)來(lai)達到對異(yi)常情(qing)況(kuang)的(de)保(bao)(bao)護(hu)(hu)，但響應速度(du)比內(nei)(nei)(nei)(nei)(nei)環(huan)慢5～10個工頻周期，因此，外(wai)環(huan)取(qu)樣主(zhu)要(yao)是調(diao)(diao)節充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流和(he)充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，兼(jian)作二次保(bao)(bao)護(hu)(hu)，而(er)(er)(er)內(nei)(nei)(nei)(nei)(nei)環(huan)取(qu)樣則是主(zhu)要(yao)的(de)，它是一(yi)次的(de)保(bao)(bao)護(hu)(hu)，這種雙環(huan)保(bao)(bao)護(hu)(hu)方式會(hui)更加安全可靠。

    3、軟(ruan)件設(she)(she)(she)計 在(zai)程(cheng)(cheng)(cheng)序(xu)的初始(shi)階段，首先(xian)是(shi)對單片(pian)機進(jin)行初始(shi)化(hua)，即(ji)根據不(bu)同(tong)的電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)設(she)(she)(she)定(ding)不(bu)同(tong)的充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)參(can)數，選擇不(bu)同(tong)的充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)策略(lve)。其(qi)后是(shi)判斷電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)是(shi)否連接正確，根據電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)壓值(zhi)判斷應(ying)(ying)該進(jin)入(ru)哪一個(ge)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)階段即(ji)小電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)預充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)，大電(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)或恒(heng)壓涓(juan)流(liu)(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)方式(shi)。在(zai)預充(chong)(chong)階段，應(ying)(ying)降(jiang)低充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)壓，而(er)在(zai)恒(heng)流(liu)(liu)(liu)方式(shi)時，應(ying)(ying)不(bu)斷檢測充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)是(shi)否達到恒(heng)定(ding)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)如(ru)1.8 A，如(ru)果(guo)小于1.8 A，則(ze)抬高電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)兩端的電(dian)(dian)(dian)(dian)(dian)(dian)壓，使之(zhi)達到1.8 A，以上調節過程(cheng)(cheng)(cheng)均(jun)可(ke)采用比例控制。在(zai)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)兩端電(dian)(dian)(dian)(dian)(dian)(dian)壓達到設(she)(she)(she)定(ding)值(zhi)后，系統再進(jin)入(ru)涓(juan)流(liu)(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)模式(shi)。該充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)的程(cheng)(cheng)(cheng)序(xu)流(liu)(liu)(liu)程(cheng)(cheng)(cheng)如(ru)圖3所示。圖3中，Is為設(she)(she)(she)定(ding)的充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(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)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)，Umin為蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)極限電(dian)(dian)(dian)(dian)(dian)(dian)壓，Umax為蓄(xu)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)極限電(dian)(dian)(dian)(dian)(dian)(dian)壓。

   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，充電器自動停止(zhi)。從(cong)測試數據來看，該(gai)設計(ji)(ji)達到了恒(heng)(heng)流(liu)快充(chong)，恒(heng)(heng)壓涓充(chong)，充(chong)滿自行關斷的設計(ji)(ji)要求(qiu)。 5、結束語(yu) 本(ben)文設計(ji)(ji)的過(guo)度(du)(du)放(fang)電預充(chong)、恒(heng)(heng)流(liu)快充(chong)、恒(heng)(heng)壓涓充(chong)、智(zhi)能控制的充(chong)電方(fang)案，能很好地解(jie)決電動自行車用電池在充(chong)電過(guo)程中存在的過(guo)充(chong)電、充(chong)電不(bu)(bu)足(zu)和發熱(re)等(deng)問(wen)題，并(bing)(bing)能根據不(bu)(bu)同電池選擇不(bu)(bu)同的充(chong)電方(fang)案。而且(qie)具有通用性(xing)。能實時(shi)檢測并(bing)(bing)顯示(shi)充(chong)電電流(liu)、充(chong)電電壓、充(chong)電時(shi)間(jian)和蓄(xu)電池溫(wen)度(du)(du)等(deng)參(can)數。由(you)于電路具有內外環控制，符合最優控制規律。最具有過(guo)流(liu)、過(guo)壓和超(chao)溫(wen)保護(hu)功能，同時(shi)由(you)于

   UC3842采用穩壓(ya)供(gong)電(dian)，因(yin)此，不但諧波污染程度(du)低，原副邊電(dian)氣(qi)隔離安全可(ke)(ke)靠，同時還可(ke)(ke)根據負載情況通過單片機來進(jin)行控制(zhi)，并(bing)可(ke)(ke)實現跳周(zhou)期模式(shi)工作。故可(ke)(ke)提高(gao)電(dian)源的效率。