近年來隨著(zhu)能(neng)源短缺問題日益突出， 太陽能(neng)、風能(neng)等新(xin)型無污染的替代能(neng)源應用日益受到重視。獨立型太陽能(neng)照明(ming)系統因其結(jie)構簡單、無需鋪設(she)電(dian)纜， 且搭建、攜(xie)帶(dai)較為方便(bian)等特(te)點在照明(ming)領域有著(zhu)廣泛應用前景。

　　但目前急(ji)需解決的有鉛(qian)酸蓄電(dian)(dian)池(chi)使(shi)用(yong)壽(shou)(shou)(shou)命(ming)較(jiao)(jiao)短及(ji)系(xi)(xi)統(tong)在(zai)(zai)(zai)弱(ruo)(ruo)光條(tiao)件(jian)下(xia)充(chong)(chong)電(dian)(dian)能(neng)(neng)力不足這兩大問題(ti)。系(xi)(xi)統(tong)儲(chu)能(neng)(neng)元(yuan)件(jian)鉛(qian)酸蓄電(dian)(dian)池(chi)設計壽(shou)(shou)(shou)命(ming)約三年， 但由(you)于充(chong)(chong)電(dian)(dian)方(fang)式、存儲(chu)方(fang)式以(yi)及(ji)人為(wei)等諸多(duo)因素(su)的影響導致其(qi)使(shi)用(yong)壽(shou)(shou)(shou)命(ming)過短，需要經(jing)常更換， 不僅(jin)加(jia)大了(le)使(shi)用(yong)成本也(ye)影響了(le)系(xi)(xi)統(tong)的穩定(ding)(ding)(ding)性。另外大部分已使(shi)用(yong)的系(xi)(xi)統(tong)在(zai)(zai)(zai)弱(ruo)(ruo)光條(tiao)件(jian)下(xia)充(chong)(chong)電(dian)(dian)能(neng)(neng)力不足， 導致系(xi)(xi)統(tong)太陽(yang)(yang)能(neng)(neng)板利用(yong)率不高(gao)； 傳統(tong)提高(gao)弱(ruo)(ruo)光充(chong)(chong)電(dian)(dian)能(neng)(neng)力的方(fang)法(fa)是采(cai)用(yong)組(zu)(zu)態優(you)化(hua)控(kong)制來實(shi)現(xian)， 即(ji)根(gen)據外界(jie)光照(zhao)強弱(ruo)(ruo)采(cai)用(yong)繼(ji)電(dian)(dian)器控(kong)制太陽(yang)(yang)能(neng)(neng)板組(zu)(zu)件(jian)按照(zhao)串(chuan)聯(lian)或(huo)并聯(lian)等不同的組(zu)(zu)合(he)方(fang)式給蓄電(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)， 確(que)保太陽(yang)(yang)能(neng)(neng)板組(zu)(zu)件(jian)輸出電(dian)(dian)壓(ya)始終達到設定(ding)(ding)(ding)充(chong)(chong)電(dian)(dian)電(dian)(dian)壓(ya)。這種方(fang)法(fa)雖然(ran)可以(yi)實(shi)現(xian)弱(ruo)(ruo)光充(chong)(chong)電(dian)(dian)， 但在(zai)(zai)(zai)組(zu)(zu)態變化(hua)的瞬間， 電(dian)(dian)路輸出電(dian)(dian)壓(ya)波動(dong)較(jiao)(jiao)大， 影響系(xi)(xi)統(tong)穩定(ding)(ding)(ding)性。此外， 由(you)于采(cai)用(yong)繼(ji)電(dian)(dian)器控(kong)制， 繼(ji)電(dian)(dian)器的機械開關觸點(dian)在(zai)(zai)(zai)工作(zuo)較(jiao)(jiao)長時間后容(rong)易磨(mo)損失靈(ling)甚至引起誤操作(zuo)。為(wei)了(le)有效(xiao)(xiao)提高(gao)系(xi)(xi)統(tong)弱(ruo)(ruo)光充(chong)(chong)電(dian)(dian)能(neng)(neng)力， 本文采(cai)用(yong)超級電(dian)(dian)容(rong)器組(zu)(zu)及(ji)升降壓(ya)電(dian)(dian)路來實(shi)現(xian)弱(ruo)(ruo)光條(tiao)件(jian)下(xia)有效(xiao)(xiao)充(chong)(chong)電(dian)(dian)， 并采(cai)用(yong)UC3909 實(shi)現(xian)對膠體密(mi)封鉛(qian)酸蓄電(dian)(dian)池(chi)智能(neng)(neng)化(hua)充(chong)(chong)電(dian)(dian)管理， 延長蓄電(dian)(dian)池(chi)使(shi)用(yong)壽(shou)(shou)(shou)命(ming)。

　　1  鉛酸蓄電池充電特性

　　鉛酸蓄(xu)電(dian)池的充電(dian)特性是由其最大(da)接受充電(dian)能力來體現， 是在保(bao)證蓄(xu)電(dian)池析氣率較低、溫升較低時所(suo)能承受的最大(da)充電(dian)電(dian)流。其充電(dian)特性曲線方程式為：

       式中， I 為(wei)(wei)(wei)充電(dian)電(dian)流； I 0為(wei)(wei)(wei)初始最大(da)充電(dian)電(dian)流； a 為(wei)(wei)(wei)最大(da)接(jie)受力比； t 為(wei)(wei)(wei)充電(dian)時間。

　　在實際的(de)(de)電(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)管理(li)過(guo)程中， 要使(shi)(shi)蓄電(dian)(dian)(dian)池(chi)的(de)(de)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)過(guo)程完(wan)全(quan)吻合該充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)特性曲(qu)線存在較大困難(nan)。因此(ci)本著提高充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)效(xiao)(xiao)率(lv)、保障蓄電(dian)(dian)(dian)池(chi)使(shi)(shi)用(yong)壽命、實現合理(li)有效(xiao)(xiao)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)的(de)(de)原則，           參考(kao)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)特性曲(qu)線， 采用(yong)智能控制芯片UC3909 實現對膠體密封鉛酸(suan)蓄電(dian)(dian)(dian)池(chi)分段充(chong)(chong)(chong)(chong)放(fang)電(dian)(dian)(dian)控制管理(li)。

　　2  基于UC3909 控制器的四階段充電

　　目前獨立(li)型太陽能照(zhao)明系統中蓄(xu)(xu)電(dian)(dian)(dian)(dian)池充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)控制器一(yi)般(ban)采用的(de)是三階(jie)段(duan)(duan)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)方式(shi)，即先恒(heng)流(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)、再恒(heng)壓(ya)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)、后浮(fu)充(chong)(chong)(chong)(chong)(chong)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)。但由于某些應用場合的(de)蓄(xu)(xu)電(dian)(dian)(dian)(dian)池會經常出現過度放電(dian)(dian)(dian)(dian)的(de)情況， 如果(guo)一(yi)開始(shi)就直接進(jin)入較(jiao)大電(dian)(dian)(dian)(dian)流(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)的(de)恒(heng)流(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)階(jie)段(duan)(duan)， 容易(yi)造成(cheng)熱失控， 易(yi)損壞(huai)蓄(xu)(xu)電(dian)(dian)(dian)(dian)池。所(suo)以在最開始(shi)的(de)時候(hou)應該采用小(xiao)電(dian)(dian)(dian)(dian)流(liu)(liu)IT 充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)的(de)涓(juan)流(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)模式(shi)， 等蓄(xu)(xu)電(dian)(dian)(dian)(dian)池的(de)端電(dian)(dian)(dian)(dian)壓(ya)達到設定的(de)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)使能電(dian)(dian)(dian)(dian)壓(ya)UT 時， 再進(jin)行恒(heng)流(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)。UC3909 芯(xin)片(pian)可以根(gen)據蓄(xu)(xu)電(dian)(dian)(dian)(dian)池的(de)狀態(tai)實現涓(juan)流(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)、恒(heng)流(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)、恒(heng)壓(ya)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)和浮(fu)充(chong)(chong)(chong)(chong)(chong)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)四個階(jie)段(duan)(duan)合理充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)， 如圖(tu)1 所(suo)示。

                                                                                         圖(tu)1  UC3909 的四階(jie)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(xing)充(chong)電(dian)， IT 一般約為0. 01C（ C 為蓄電(dian)池容量）狀態2: 恒流(liu)充(chong)電(dian)。

　　當蓄電(dian)(dian)(dian)(dian)池的(de)電(dian)(dian)(dian)(dian)壓(ya)(ya)達到充(chong)(chong)電(dian)(dian)(dian)(dian)使能(neng)電(dian)(dian)(dian)(dian)壓(ya)(ya)UT 時， 充(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)提供一(yi)個大電(dian)(dian)(dian)(dian)流(liu)I BULK 對蓄電(dian)(dian)(dian)(dian)池進(jin)行(xing)恒(heng)流(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)， 這一(yi)階(jie)段(duan)是充(chong)(chong)電(dian)(dian)(dian)(dian)的(de)主要階(jie)段(duan)， 蓄電(dian)(dian)(dian)(dian)池端(duan)電(dian)(dian)(dian)(dian)壓(ya)(ya)上(shang)升(sheng)(sheng)很快， 直至電(dian)(dian)(dian)(dian)壓(ya)(ya)上(shang)升(sheng)(sheng)到過壓(ya)(ya)充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓(ya)(ya)UOC 時進(jin)入恒(heng)壓(ya)(ya)充(chong)(chong)電(dian)(dian)(dian)(dian)階(jie)段(duan)。

　　狀態3: 恒壓充電。

　　在此(ci)階段， 充(chong)電(dian)(dian)器提供一個略高(gao)于蓄(xu)電(dian)(dian)池(chi)額定值(zhi)的(de)電(dian)(dian)壓(ya)UOC進(jin)行(xing)恒壓(ya)充(chong)電(dian)(dian)， 電(dian)(dian)路的(de)充(chong)電(dian)(dian)電(dian)(dian)流將按指(zhi)數規律逐漸(jian)減(jian)小(xiao)(xiao)， 直至電(dian)(dian)流大小(xiao)(xiao)等(deng)于充(chong)電(dian)(dian)終止電(dian)(dian)流I OCT（約為(wei)10 % IBULK ） , 蓄(xu)電(dian)(dian)池(chi)已被充(chong)滿(man)， 充(chong)電(dian)(dian)器進(jin)入浮充(chong)充(chong)電(dian)(dian)狀態。

　　狀態4: 浮充充電。

　　浮(fu)(fu)充(chong)(chong)充(chong)(chong)電(dian)(dian)階段， 充(chong)(chong)電(dian)(dian)器提(ti)供浮(fu)(fu)充(chong)(chong)電(dian)(dian)壓(ya)UF 對蓄(xu)電(dian)(dian)池(chi)(chi)以(yi)很小的(de)浮(fu)(fu)充(chong)(chong)電(dian)(dian)流進行(xing)(xing)充(chong)(chong)電(dian)(dian)， 以(yi)彌補蓄(xu)電(dian)(dian)池(chi)(chi)自放電(dian)(dian)造成(cheng)的(de)容(rong)量損失。同時由于蓄(xu)電(dian)(dian)池(chi)(chi)的(de)浮(fu)(fu)充(chong)(chong)電(dian)(dian)壓(ya)隨溫度(du)變化而變化， 因(yin)此需(xu)要選擇與蓄(xu)電(dian)(dian)池(chi)(chi)相(xiang)同溫度(du)系(xi)數的(de)熱敏(min)電(dian)(dian)阻進行(xing)(xing)溫度(du)補償， 確保在任(ren)何溫度(du)下都能以(yi)精確的(de)浮(fu)(fu)充(chong)(chong)電(dian)(dian)壓(ya)進行(xing)(xing)浮(fu)(fu)充(chong)(chong)充(chong)(chong)電(dian)(dian)。溫度(du)系(xi)數一(yi)般選擇- 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)路框圖， 光伏(fu)陣(zhen)列(lie)經過(guo)電(dian)(dian)壓電(dian)(dian)流采樣再經模數轉(zhuan)換(huan)將數字信號反饋(kui)至單片機(ji)， 單片機(ji)根據光伏(fu)陣(zhen)列(lie)的工作狀況輸出PWM 信號去驅動PMOS 管， 實(shi)現(xian)對(dui)光伏(fu)陣(zhen)列(lie)的最大功率跟蹤。超(chao)(chao)級(ji)電(dian)(dian)容器組、DC/ DC 變(bian)(bian)換(huan)器、UC3909 用來實(shi)現(xian)對(dui)閥(fa)控鉛酸(suan)蓄電(dian)(dian)池(chi)的四(si)階段充(chong)(chong)(chong)電(dian)(dian)控制， 并利用超(chao)(chao)級(ji)電(dian)(dian)容的特性優化充(chong)(chong)(chong)放(fang)電(dian)(dian)過(guo)程。本文側重(zhong)對(dui)超(chao)(chao)級(ji)電(dian)(dian)容器組、U C3909 及(ji)DC/ DC 變(bian)(bian)換(huan)器等部分實(shi)現(xian)對(dui)閥(fa)控鉛酸(suan)蓄電(dian)(dian)池(chi)四(si)階段的充(chong)(chong)(chong)電(dian)(dian)分析及(ji)設計。

圖2  系統框圖

　　3. 1  UC3909 充電(dian)器主(zhu)要參數設計(ji)

　　基于UC3909 的充放電(dian)電(dian)路(lu)如(ru)圖3 所示。

      圖3  基于(yu)UC3909的(de)充放電電路(lu)

　　根據UC3909 內(nei)部集成電(dian)(dian)(dian)路(lu)及光伏陣列、超(chao)級(ji)電(dian)(dian)(dian)容(rong)參數(shu)并(bing)結合閥控鉛酸蓄(xu)電(dian)(dian)(dian)池(chi)的(de)容(rong)量及額(e)定電(dian)(dian)(dian)壓等參數(shu)對電(dian)(dian)(dian)路(lu)各(ge)個部分進(jin)行合理計算(suan)設(she)計。本(ben)設(she)計使用賽特公(gong)司生產的(de)12 V, 65 Ah膠(jiao)體密(mi)封鉛酸蓄(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)電(dian)(dian)(dian)參數(shu)， 浮(fu)充(chong)電(dian)(dian)(dian)壓UF 取(qu)(qu)13. 8 V,充(chong)電(dian)(dian)(dian)使能電(dian)(dian)(dian)壓UT 取(qu)(qu)10. 8 V; 過壓充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)壓UOC 14. 7V; 涓流(liu)(liu)充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)I TC 取(qu)(qu)0. 26 A; 恒流(liu)(liu)充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)I BU LK 取(qu)(qu)系統最(zui)大充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)6. 5 A; 過充(chong)終(zhong)止電(dian)(dian)(dian)流(liu)(liu)IOCT 取(qu)(qu)1 A.

　　根據以上廠家所提供的(de)蓄電池參(can)數， 參(can)照UC3909 芯(xin)片資(zi)料及相關參(can)考文獻，計算U C3909 外圍元(yuan)件參(can)數， R S1、RS2 、RS3、RS4計算公式如下：

　　式中， UREF 為UC3909 內部基準(zhun)電壓2. 3 V.代入相關值計算得(de)（ R S1、RS2、RS3、RS4 分(fen)別(bie)為245 k Ω 、16 kΩ  、53kΩ 、975 kΩ 。

　　另外， 可以(yi)根據(ju)流(liu)(liu)入U C3909 內部電流(liu)(liu)誤差放大器反向輸出端CA 的固定控(kong)制電流(liu)(liu)ITRCK 、涓流(liu)(liu)充(chong)電電流(liu)(liu)I T 、恒流(liu)(liu)充(chong)電電流(liu)(liu)IBULK及過充(chong)終止電流(liu)(liu)IOCT 計算(suan)得出RG1、RG2 , R OVC1和ROVC2 , 其基(ji)本計算(suan)公式(shi)如下(xia)：

　　RSET 取11. 5 k  , 電(dian)流采樣電(dian)阻RS 取55 m  , 代入式（ 5）、（ 6） 得：

ROVC1和R OVC2滿足以下關系式:

　　最終ROVC1和ROVC2 分(fen)別選取為1 k Ω  , 10 kΩ