近年(nian)來隨著(zhu)能(neng)源短缺問題日(ri)益突出， 太陽能(neng)、風能(neng)等新型無(wu)污(wu)染的替代能(neng)源應用日(ri)益受到(dao)重視。獨立型太陽能(neng)照(zhao)明(ming)系統(tong)因其結構(gou)簡單、無(wu)需鋪設電(dian)纜， 且搭建、攜帶較為(wei)方便(bian)等特點(dian)在照(zhao)明(ming)領域有(you)著(zhu)廣泛(fan)應用前景。

　　但目前(qian)急需(xu)(xu)解決的(de)有(you)鉛酸(suan)蓄電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)使(shi)用(yong)壽(shou)(shou)(shou)命(ming)較短(duan)及系(xi)統(tong)在(zai)(zai)弱(ruo)光(guang)(guang)(guang)條件(jian)(jian)下充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)能(neng)(neng)力不(bu)足這兩(liang)大(da)問題。系(xi)統(tong)儲(chu)(chu)能(neng)(neng)元件(jian)(jian)鉛酸(suan)蓄電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)設(she)計壽(shou)(shou)(shou)命(ming)約(yue)三年， 但由于充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)方(fang)(fang)式、存儲(chu)(chu)方(fang)(fang)式以及人為(wei)等諸多因素的(de)影(ying)響導(dao)致其使(shi)用(yong)壽(shou)(shou)(shou)命(ming)過短(duan)，需(xu)(xu)要經(jing)常更(geng)換， 不(bu)僅(jin)加大(da)了(le)使(shi)用(yong)成本也影(ying)響了(le)系(xi)統(tong)的(de)穩(wen)(wen)定性。另外(wai)大(da)部分已使(shi)用(yong)的(de)系(xi)統(tong)在(zai)(zai)弱(ruo)光(guang)(guang)(guang)條件(jian)(jian)下充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)能(neng)(neng)力不(bu)足， 導(dao)致系(xi)統(tong)太(tai)陽(yang)能(neng)(neng)板利用(yong)率不(bu)高； 傳(chuan)統(tong)提高弱(ruo)光(guang)(guang)(guang)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)能(neng)(neng)力的(de)方(fang)(fang)法是采(cai)用(yong)組態優化(hua)控(kong)制(zhi)來實(shi)現(xian)， 即(ji)根據外(wai)界光(guang)(guang)(guang)照(zhao)強弱(ruo)采(cai)用(yong)繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)控(kong)制(zhi)太(tai)陽(yang)能(neng)(neng)板組件(jian)(jian)按照(zhao)串聯或并(bing)聯等不(bu)同的(de)組合(he)方(fang)(fang)式給蓄電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)， 確(que)保太(tai)陽(yang)能(neng)(neng)板組件(jian)(jian)輸出電(dian)(dian)(dian)(dian)(dian)壓始(shi)終達到設(she)定充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)壓。這種方(fang)(fang)法雖然可以實(shi)現(xian)弱(ruo)光(guang)(guang)(guang)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)， 但在(zai)(zai)組態變(bian)化(hua)的(de)瞬間， 電(dian)(dian)(dian)(dian)(dian)路(lu)輸出電(dian)(dian)(dian)(dian)(dian)壓波動較大(da)， 影(ying)響系(xi)統(tong)穩(wen)(wen)定性。此(ci)外(wai)， 由于采(cai)用(yong)繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)控(kong)制(zhi)， 繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)的(de)機械開關(guan)觸點在(zai)(zai)工作較長(chang)時間后容易磨(mo)損失靈甚至引起(qi)誤(wu)操作。為(wei)了(le)有(you)效提高系(xi)統(tong)弱(ruo)光(guang)(guang)(guang)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)能(neng)(neng)力， 本文采(cai)用(yong)超級電(dian)(dian)(dian)(dian)(dian)容器(qi)組及升(sheng)降壓電(dian)(dian)(dian)(dian)(dian)路(lu)來實(shi)現(xian)弱(ruo)光(guang)(guang)(guang)條件(jian)(jian)下有(you)效充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)， 并(bing)采(cai)用(yong)UC3909 實(shi)現(xian)對膠體密封鉛酸(suan)蓄電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)智能(neng)(neng)化(hua)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)管(guan)理(li)， 延長(chang)蓄電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)使(shi)用(yong)壽(shou)(shou)(shou)命(ming)。

　　1  鉛酸蓄電池充電特性

　　鉛酸蓄電(dian)池的充(chong)電(dian)特性是(shi)由其(qi)最大接受充(chong)電(dian)能力來體現， 是(shi)在保(bao)證蓄電(dian)池析氣率(lv)較低、溫升較低時所能承受的最大充(chong)電(dian)電(dian)流(liu)。其(qi)充(chong)電(dian)特性曲線方程式為：

       式中， I 為充電電流(liu)(liu)； I 0為初(chu)始最(zui)大(da)充電電流(liu)(liu)； a 為最(zui)大(da)接受(shou)力比； t 為充電時(shi)間(jian)。

　　在實際的電(dian)(dian)(dian)池(chi)充(chong)電(dian)(dian)(dian)管理(li)過程中， 要使(shi)(shi)蓄電(dian)(dian)(dian)池(chi)的充(chong)電(dian)(dian)(dian)過程完全吻合該(gai)充(chong)電(dian)(dian)(dian)特性曲線(xian)存在較大困難。因(yin)此本著提(ti)高充(chong)電(dian)(dian)(dian)效率、保障蓄電(dian)(dian)(dian)池(chi)使(shi)(shi)用(yong)壽命、實現合理(li)有效充(chong)電(dian)(dian)(dian)的原則，           參考充(chong)電(dian)(dian)(dian)特性曲線(xian)， 采用(yong)智能控制芯(xin)片UC3909 實現對膠體(ti)密封鉛酸(suan)蓄電(dian)(dian)(dian)池(chi)分段(duan)充(chong)放電(dian)(dian)(dian)控制管理(li)。

　　2  基于UC3909 控制器的四階段充電

　　目(mu)前獨立型太陽能(neng)照明系統中蓄(xu)電(dian)(dian)(dian)池充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)控制(zhi)器一般采用(yong)的(de)是三階段充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)方式，即(ji)先(xian)恒(heng)流(liu)(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)、再恒(heng)壓充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)、后浮(fu)充(chong)(chong)(chong)(chong)(chong)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)。但(dan)由于某些應(ying)用(yong)場合(he)的(de)蓄(xu)電(dian)(dian)(dian)池會(hui)經常出(chu)現過度放電(dian)(dian)(dian)的(de)情況， 如果一開始就直接進(jin)入較大(da)電(dian)(dian)(dian)流(liu)(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)的(de)恒(heng)流(liu)(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)階段， 容易造(zao)成熱失控， 易損(sun)壞蓄(xu)電(dian)(dian)(dian)池。所以(yi)在最開始的(de)時候應(ying)該采用(yong)小(xiao)電(dian)(dian)(dian)流(liu)(liu)(liu)IT 充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)的(de)涓流(liu)(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)模(mo)式， 等蓄(xu)電(dian)(dian)(dian)池的(de)端電(dian)(dian)(dian)壓達到設定的(de)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)使能(neng)電(dian)(dian)(dian)壓UT 時， 再進(jin)行恒(heng)流(liu)(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)。UC3909 芯片(pian)可以(yi)根(gen)據蓄(xu)電(dian)(dian)(dian)池的(de)狀態(tai)實現涓流(liu)(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)、恒(heng)流(liu)(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)、恒(heng)壓充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)和浮(fu)充(chong)(chong)(chong)(chong)(chong)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)四個階段合(he)理充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)， 如圖1 所示。

                                                                                         圖1  UC3909 的四階段充(chong)電曲線

　　狀態1: 涓流充電。

　　當蓄電池電壓低于充電使能電壓UT , 充電器提供很小的涓流(liu)IT 進行充(chong)電(dian)(dian)， IT 一(yi)般約為0. 01C（ C 為蓄電(dian)(dian)池容量）狀態(tai)2: 恒(heng)流(liu)充(chong)電(dian)(dian)。

　　當蓄(xu)電(dian)(dian)(dian)(dian)池的(de)電(dian)(dian)(dian)(dian)壓(ya)達到(dao)充電(dian)(dian)(dian)(dian)使能電(dian)(dian)(dian)(dian)壓(ya)UT 時， 充電(dian)(dian)(dian)(dian)器提(ti)供(gong)一(yi)個(ge)大電(dian)(dian)(dian)(dian)流I BULK 對蓄(xu)電(dian)(dian)(dian)(dian)池進行(xing)恒流充電(dian)(dian)(dian)(dian)， 這一(yi)階段是(shi)充電(dian)(dian)(dian)(dian)的(de)主要階段， 蓄(xu)電(dian)(dian)(dian)(dian)池端電(dian)(dian)(dian)(dian)壓(ya)上(shang)升很快(kuai)， 直至電(dian)(dian)(dian)(dian)壓(ya)上(shang)升到(dao)過壓(ya)充電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓(ya)UOC 時進入恒壓(ya)充電(dian)(dian)(dian)(dian)階段。

　　狀態3: 恒壓充電。

　　在此階段， 充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器提(ti)供一個略(lve)高于蓄電(dian)(dian)(dian)池額定值的電(dian)(dian)(dian)壓UOC進行恒壓充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)， 電(dian)(dian)(dian)路的充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流將(jiang)按(an)指(zhi)數規律逐漸減小， 直至電(dian)(dian)(dian)流大小等于充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)終(zhong)止(zhi)電(dian)(dian)(dian)流I OCT（約(yue)為10 % IBULK ） , 蓄電(dian)(dian)(dian)池已被充(chong)(chong)(chong)(chong)滿， 充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)器進入浮充(chong)(chong)(chong)(chong)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)狀態。

　　狀態4: 浮充充電。

　　浮充(chong)(chong)充(chong)(chong)電(dian)(dian)階段， 充(chong)(chong)電(dian)(dian)器(qi)提供浮充(chong)(chong)電(dian)(dian)壓(ya)UF 對蓄電(dian)(dian)池(chi)以很小(xiao)的(de)浮充(chong)(chong)電(dian)(dian)流(liu)進(jin)(jin)行(xing)充(chong)(chong)電(dian)(dian)， 以彌(mi)補蓄電(dian)(dian)池(chi)自(zi)放電(dian)(dian)造成(cheng)的(de)容量損失。同時由于(yu)蓄電(dian)(dian)池(chi)的(de)浮充(chong)(chong)電(dian)(dian)壓(ya)隨(sui)溫(wen)度(du)(du)變(bian)化而變(bian)化， 因此需要(yao)選擇(ze)(ze)與蓄電(dian)(dian)池(chi)相同溫(wen)度(du)(du)系數的(de)熱敏電(dian)(dian)阻進(jin)(jin)行(xing)溫(wen)度(du)(du)補償， 確(que)保在任何溫(wen)度(du)(du)下都能以精確(que)的(de)浮充(chong)(chong)電(dian)(dian)壓(ya)進(jin)(jin)行(xing)浮充(chong)(chong)充(chong)(chong)電(dian)(dian)。溫(wen)度(du)(du)系數一般選擇(ze)(ze)- 3. 5~ - 5 mV/ .

　　3  充電電路設計

　　圖2 所示為基于U C3909 太陽能蓄電池充電器電(dian)(dian)(dian)路框圖， 光(guang)伏(fu)(fu)陣(zhen)(zhen)列經(jing)過電(dian)(dian)(dian)壓電(dian)(dian)(dian)流采(cai)樣再經(jing)模數轉(zhuan)換(huan)將數字信號(hao)(hao)反饋至單片機， 單片機根據光(guang)伏(fu)(fu)陣(zhen)(zhen)列的(de)工作狀況輸(shu)出PWM 信號(hao)(hao)去驅(qu)動PMOS 管(guan)， 實(shi)現(xian)對(dui)(dui)光(guang)伏(fu)(fu)陣(zhen)(zhen)列的(de)最(zui)大功率跟蹤。超(chao)(chao)級(ji)(ji)(ji)電(dian)(dian)(dian)容(rong)器(qi)組、DC/ DC 變(bian)換(huan)器(qi)、UC3909 用來(lai)實(shi)現(xian)對(dui)(dui)閥控鉛酸(suan)蓄電(dian)(dian)(dian)池的(de)四階段充電(dian)(dian)(dian)控制(zhi)， 并利用超(chao)(chao)級(ji)(ji)(ji)電(dian)(dian)(dian)容(rong)的(de)特(te)性優化充放電(dian)(dian)(dian)過程。本文(wen)側重(zhong)對(dui)(dui)超(chao)(chao)級(ji)(ji)(ji)電(dian)(dian)(dian)容(rong)器(qi)組、U C3909 及DC/ DC 變(bian)換(huan)器(qi)等(deng)部(bu)分(fen)實(shi)現(xian)對(dui)(dui)閥控鉛酸(suan)蓄電(dian)(dian)(dian)池四階段的(de)充電(dian)(dian)(dian)分(fen)析(xi)及設計。

圖(tu)2  系統框圖(tu)

　　3. 1  UC3909 充電器(qi)主要參數設(she)計

　　基于UC3909 的充放電(dian)電(dian)路如圖(tu)3 所(suo)示。

      圖3  基于UC3909的充放電(dian)電(dian)路

　　根據UC3909 內部集成(cheng)電(dian)(dian)(dian)路及光伏陣列(lie)、超級電(dian)(dian)(dian)容參數(shu)并結合閥(fa)控鉛(qian)酸蓄(xu)電(dian)(dian)(dian)池(chi)的(de)容量及額定(ding)電(dian)(dian)(dian)壓等(deng)參數(shu)對電(dian)(dian)(dian)路各個部分進行(xing)合理計算設計。本設計使用賽(sai)特公(gong)司生產的(de)12 V, 65 Ah膠體密(mi)封鉛(qian)酸蓄(xu)電(dian)(dian)(dian)池(chi)， 根據廠家提供的(de)蓄(xu)電(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)電(dian)(dian)(dian)參數(shu)， 浮(fu)充(chong)(chong)(chong)電(dian)(dian)(dian)壓UF 取13. 8 V,充(chong)(chong)(chong)電(dian)(dian)(dian)使能電(dian)(dian)(dian)壓UT 取10. 8 V; 過(guo)壓充(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)壓UOC 14. 7V; 涓流充(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流I TC 取0. 26 A; 恒流充(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流I BU LK 取系統最(zui)大充(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流6. 5 A; 過(guo)充(chong)(chong)(chong)終止電(dian)(dian)(dian)流IOCT 取1 A.

　　根據以上(shang)廠家(jia)所提供的蓄電池參數(shu)， 參照UC3909 芯(xin)片資料及相關參考文獻，計(ji)算U C3909 外圍(wei)元件(jian)參數(shu)， R S1、RS2 、RS3、RS4計(ji)算公式如下(xia)：

　　式(shi)中， UREF 為UC3909 內部基準(zhun)電壓2. 3 V.代入(ru)相關(guan)值計算得（ R S1、RS2、RS3、RS4 分(fen)別為245 k Ω 、16 kΩ  、53kΩ 、975 kΩ 。

　　另外， 可以根據流入(ru)U C3909 內部電(dian)(dian)(dian)流誤差放大器反向(xiang)輸出端CA 的固定(ding)控制(zhi)電(dian)(dian)(dian)流ITRCK 、涓流充電(dian)(dian)(dian)電(dian)(dian)(dian)流I T 、恒流充電(dian)(dian)(dian)電(dian)(dian)(dian)流IBULK及(ji)過充終止電(dian)(dian)(dian)流IOCT 計(ji)算(suan)得出RG1、RG2 , R OVC1和(he)ROVC2 , 其基本計(ji)算(suan)公式如(ru)下：

　　RSET 取11. 5 k  , 電(dian)流(liu)采樣電(dian)阻(zu)RS 取55 m  , 代(dai)入式（ 5）、（ 6） 得：

ROVC1和R OVC2滿足以下(xia)關系式:

　　最(zui)終(zhong)ROVC1和ROVC2 分(fen)別選取(qu)為1 k Ω  , 10 kΩ