近年(nian)來隨著能(neng)源短缺問題日(ri)益(yi)突(tu)出， 太陽(yang)能(neng)、風(feng)能(neng)等(deng)新型(xing)無污(wu)染(ran)的替(ti)代能(neng)源應用日(ri)益(yi)受到(dao)重視(shi)。獨立型(xing)太陽(yang)能(neng)照明系統因其結構簡單、無需鋪設(she)電纜， 且搭(da)建(jian)、攜帶(dai)較為(wei)方(fang)便等(deng)特點在照明領域有著廣(guang)泛應用前(qian)景。

　　但目前急需(xu)解決(jue)的(de)有鉛酸蓄(xu)電(dian)(dian)(dian)(dian)(dian)池使(shi)用(yong)(yong)(yong)壽命較短及系統(tong)在(zai)弱(ruo)(ruo)(ruo)光(guang)(guang)條(tiao)件下充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)能(neng)(neng)力(li)不(bu)(bu)足這(zhe)兩(liang)大(da)(da)(da)問題。系統(tong)儲(chu)能(neng)(neng)元件鉛酸蓄(xu)電(dian)(dian)(dian)(dian)(dian)池設計壽命約三年， 但由于(yu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)方式(shi)、存儲(chu)方式(shi)以及人(ren)為等諸多因素的(de)影(ying)響導致(zhi)其(qi)使(shi)用(yong)(yong)(yong)壽命過短，需(xu)要經常(chang)更換， 不(bu)(bu)僅加大(da)(da)(da)了使(shi)用(yong)(yong)(yong)成本也影(ying)響了系統(tong)的(de)穩定性(xing)。另外(wai)大(da)(da)(da)部分已使(shi)用(yong)(yong)(yong)的(de)系統(tong)在(zai)弱(ruo)(ruo)(ruo)光(guang)(guang)條(tiao)件下充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)能(neng)(neng)力(li)不(bu)(bu)足， 導致(zhi)系統(tong)太陽(yang)(yang)能(neng)(neng)板(ban)利(li)用(yong)(yong)(yong)率(lv)不(bu)(bu)高； 傳(chuan)統(tong)提高弱(ruo)(ruo)(ruo)光(guang)(guang)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)能(neng)(neng)力(li)的(de)方法是采用(yong)(yong)(yong)組(zu)態優化控制來實(shi)現， 即(ji)根據外(wai)界光(guang)(guang)照(zhao)(zhao)強(qiang)弱(ruo)(ruo)(ruo)采用(yong)(yong)(yong)繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)(qi)控制太陽(yang)(yang)能(neng)(neng)板(ban)組(zu)件按(an)照(zhao)(zhao)串聯(lian)或并聯(lian)等不(bu)(bu)同的(de)組(zu)合方式(shi)給蓄(xu)電(dian)(dian)(dian)(dian)(dian)池充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)， 確保太陽(yang)(yang)能(neng)(neng)板(ban)組(zu)件輸出電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)始(shi)終(zhong)達到設定充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)。這(zhe)種方法雖然可以實(shi)現弱(ruo)(ruo)(ruo)光(guang)(guang)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)， 但在(zai)組(zu)態變(bian)化的(de)瞬間(jian)， 電(dian)(dian)(dian)(dian)(dian)路輸出電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)波動較大(da)(da)(da)， 影(ying)響系統(tong)穩定性(xing)。此(ci)外(wai)， 由于(yu)采用(yong)(yong)(yong)繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)(qi)控制， 繼(ji)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)(qi)的(de)機(ji)械開關觸點在(zai)工作較長時間(jian)后容易磨損失(shi)靈甚至引起誤操作。為了有效提高系統(tong)弱(ruo)(ruo)(ruo)光(guang)(guang)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)能(neng)(neng)力(li)， 本文采用(yong)(yong)(yong)超級電(dian)(dian)(dian)(dian)(dian)容器(qi)(qi)(qi)組(zu)及升降壓(ya)(ya)電(dian)(dian)(dian)(dian)(dian)路來實(shi)現弱(ruo)(ruo)(ruo)光(guang)(guang)條(tiao)件下有效充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)， 并采用(yong)(yong)(yong)UC3909 實(shi)現對膠體密封鉛酸蓄(xu)電(dian)(dian)(dian)(dian)(dian)池智能(neng)(neng)化充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)管理， 延長蓄(xu)電(dian)(dian)(dian)(dian)(dian)池使(shi)用(yong)(yong)(yong)壽命。

　　1  鉛酸蓄電池充電特性

　　鉛酸(suan)蓄(xu)電(dian)池(chi)的(de)(de)充(chong)電(dian)特(te)性是(shi)由其最大接受充(chong)電(dian)能力來體現， 是(shi)在保證蓄(xu)電(dian)池(chi)析氣率較低(di)、溫升較低(di)時所能承受的(de)(de)最大充(chong)電(dian)電(dian)流(liu)。其充(chong)電(dian)特(te)性曲線方程式為：

       式中， I 為充(chong)電(dian)(dian)電(dian)(dian)流； I 0為初始最(zui)大充(chong)電(dian)(dian)電(dian)(dian)流； a 為最(zui)大接受力比； t 為充(chong)電(dian)(dian)時間。

　　在實(shi)際的電(dian)(dian)池(chi)充(chong)電(dian)(dian)管(guan)理(li)過程中， 要(yao)使蓄(xu)電(dian)(dian)池(chi)的充(chong)電(dian)(dian)過程完全吻(wen)合該充(chong)電(dian)(dian)特性曲線存在較大困難。因此本著(zhu)提(ti)高充(chong)電(dian)(dian)效率、保障蓄(xu)電(dian)(dian)池(chi)使用壽命、實(shi)現合理(li)有(you)效充(chong)電(dian)(dian)的原則，           參考充(chong)電(dian)(dian)特性曲線， 采用智能控制芯(xin)片UC3909 實(shi)現對膠體密封鉛酸蓄(xu)電(dian)(dian)池(chi)分段充(chong)放電(dian)(dian)控制管(guan)理(li)。

　　2  基于UC3909 控制器的四階段充電

　　目前獨立(li)型(xing)太陽能(neng)(neng)照明系統(tong)中蓄(xu)(xu)電(dian)(dian)(dian)(dian)池充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)控(kong)制器一般采(cai)用(yong)的是三階(jie)段(duan)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)方(fang)式，即先恒(heng)流充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)、再(zai)恒(heng)壓(ya)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)、后浮(fu)充(chong)(chong)(chong)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)。但(dan)由于某些應用(yong)場合的蓄(xu)(xu)電(dian)(dian)(dian)(dian)池會經(jing)常(chang)出(chu)現過度放(fang)電(dian)(dian)(dian)(dian)的情(qing)況， 如果一開始(shi)就直(zhi)接進(jin)入較大電(dian)(dian)(dian)(dian)流充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)的恒(heng)流充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)階(jie)段(duan)， 容易(yi)造(zao)成(cheng)熱失控(kong)， 易(yi)損壞蓄(xu)(xu)電(dian)(dian)(dian)(dian)池。所(suo)以(yi)在最開始(shi)的時候應該采(cai)用(yong)小電(dian)(dian)(dian)(dian)流IT 充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)的涓流充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)模式， 等蓄(xu)(xu)電(dian)(dian)(dian)(dian)池的端電(dian)(dian)(dian)(dian)壓(ya)達到(dao)設定的充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)使能(neng)(neng)電(dian)(dian)(dian)(dian)壓(ya)UT 時， 再(zai)進(jin)行恒(heng)流充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)。UC3909 芯片可以(yi)根據蓄(xu)(xu)電(dian)(dian)(dian)(dian)池的狀態實現涓流充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)、恒(heng)流充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)、恒(heng)壓(ya)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)和浮(fu)充(chong)(chong)(chong)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)四個階(jie)段(duan)合理充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)， 如圖1 所(suo)示(shi)。

                                                                                         圖(tu)1  UC3909 的四階段充電曲(qu)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 進行充電， IT 一般(ban)約(yue)為0. 01C（ C 為蓄(xu)電池容量）狀態2: 恒流(liu)充電。

　　當蓄(xu)電(dian)(dian)(dian)池的電(dian)(dian)(dian)壓(ya)(ya)(ya)達到充(chong)(chong)(chong)電(dian)(dian)(dian)使能電(dian)(dian)(dian)壓(ya)(ya)(ya)UT 時(shi)， 充(chong)(chong)(chong)電(dian)(dian)(dian)器提供(gong)一(yi)個大電(dian)(dian)(dian)流(liu)I BULK 對蓄(xu)電(dian)(dian)(dian)池進行恒流(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)， 這一(yi)階段(duan)是(shi)充(chong)(chong)(chong)電(dian)(dian)(dian)的主要階段(duan)， 蓄(xu)電(dian)(dian)(dian)池端電(dian)(dian)(dian)壓(ya)(ya)(ya)上(shang)升很快， 直至電(dian)(dian)(dian)壓(ya)(ya)(ya)上(shang)升到過壓(ya)(ya)(ya)充(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)壓(ya)(ya)(ya)UOC 時(shi)進入恒壓(ya)(ya)(ya)充(chong)(chong)(chong)電(dian)(dian)(dian)階段(duan)。

　　狀態3: 恒壓充電。

　　在此階段(duan)， 充(chong)(chong)電(dian)(dian)(dian)(dian)器提供(gong)一(yi)個略高(gao)于蓄電(dian)(dian)(dian)(dian)池額定值的電(dian)(dian)(dian)(dian)壓UOC進(jin)行(xing)恒壓充(chong)(chong)電(dian)(dian)(dian)(dian)， 電(dian)(dian)(dian)(dian)路的充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流將按指數規律逐(zhu)漸減(jian)小， 直(zhi)至電(dian)(dian)(dian)(dian)流大小等(deng)于充(chong)(chong)電(dian)(dian)(dian)(dian)終止電(dian)(dian)(dian)(dian)流I OCT（約為10 % IBULK ） , 蓄電(dian)(dian)(dian)(dian)池已被充(chong)(chong)滿， 充(chong)(chong)電(dian)(dian)(dian)(dian)器進(jin)入浮充(chong)(chong)充(chong)(chong)電(dian)(dian)(dian)(dian)狀態。

　　狀態4: 浮充充電。

　　浮充充電(dian)(dian)(dian)(dian)階段， 充電(dian)(dian)(dian)(dian)器提供(gong)浮充電(dian)(dian)(dian)(dian)壓UF 對蓄(xu)(xu)電(dian)(dian)(dian)(dian)池(chi)以很小的浮充電(dian)(dian)(dian)(dian)流進行充電(dian)(dian)(dian)(dian)， 以彌(mi)補蓄(xu)(xu)電(dian)(dian)(dian)(dian)池(chi)自放電(dian)(dian)(dian)(dian)造成的容(rong)量損失(shi)。同(tong)時由于蓄(xu)(xu)電(dian)(dian)(dian)(dian)池(chi)的浮充電(dian)(dian)(dian)(dian)壓隨溫(wen)度變化(hua)而變化(hua)， 因此需要選擇與蓄(xu)(xu)電(dian)(dian)(dian)(dian)池(chi)相同(tong)溫(wen)度系(xi)(xi)數的熱敏電(dian)(dian)(dian)(dian)阻進行溫(wen)度補償， 確(que)保在任何溫(wen)度下(xia)都能以精確(que)的浮充電(dian)(dian)(dian)(dian)壓進行浮充充電(dian)(dian)(dian)(dian)。溫(wen)度系(xi)(xi)數一般選擇- 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)路框圖， 光(guang)(guang)(guang)伏(fu)(fu)陣列經(jing)過電(dian)壓(ya)電(dian)流采樣再經(jing)模數(shu)轉換(huan)(huan)將數(shu)字信號反(fan)饋(kui)至單片機(ji)(ji)， 單片機(ji)(ji)根據光(guang)(guang)(guang)伏(fu)(fu)陣列的工作狀況輸出(chu)PWM 信號去驅動PMOS 管， 實現(xian)對(dui)光(guang)(guang)(guang)伏(fu)(fu)陣列的最(zui)大(da)功率跟蹤。超級電(dian)容(rong)(rong)器(qi)(qi)組(zu)、DC/ DC 變換(huan)(huan)器(qi)(qi)、UC3909 用來實現(xian)對(dui)閥(fa)控(kong)(kong)鉛酸蓄(xu)電(dian)池的四階(jie)段充(chong)電(dian)控(kong)(kong)制， 并利用超級電(dian)容(rong)(rong)的特性優化充(chong)放電(dian)過程。本文(wen)側重(zhong)對(dui)超級電(dian)容(rong)(rong)器(qi)(qi)組(zu)、U C3909 及(ji)DC/ DC 變換(huan)(huan)器(qi)(qi)等部分實現(xian)對(dui)閥(fa)控(kong)(kong)鉛酸蓄(xu)電(dian)池四階(jie)段的充(chong)電(dian)分析及(ji)設計。

圖2  系(xi)統框圖

　　3. 1  UC3909 充電器主要參數設計

　　基于(yu)UC3909 的充放電電路如圖3 所(suo)示。

      圖(tu)3  基于UC3909的充放電電路

　　根據(ju)(ju)UC3909 內部(bu)集(ji)成電(dian)(dian)(dian)路及光伏陣(zhen)列、超級電(dian)(dian)(dian)容(rong)參數(shu)(shu)并結合閥(fa)控鉛酸蓄(xu)(xu)電(dian)(dian)(dian)池(chi)的(de)容(rong)量及額定電(dian)(dian)(dian)壓等參數(shu)(shu)對電(dian)(dian)(dian)路各(ge)個部(bu)分進行合理計(ji)算設(she)計(ji)。本設(she)計(ji)使用賽特公司生產的(de)12 V, 65 Ah膠體密封鉛酸蓄(xu)(xu)電(dian)(dian)(dian)池(chi)， 根據(ju)(ju)廠家提供的(de)蓄(xu)(xu)電(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)參數(shu)(shu)， 浮充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)壓UF 取(qu)13. 8 V,充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)使能電(dian)(dian)(dian)壓UT 取(qu)10. 8 V; 過壓充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)壓UOC 14. 7V; 涓(juan)流(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)I TC 取(qu)0. 26 A; 恒流(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)I BU LK 取(qu)系(xi)統最大充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)6. 5 A; 過充(chong)(chong)(chong)(chong)(chong)終止(zhi)電(dian)(dian)(dian)流(liu)(liu)IOCT 取(qu)1 A.

　　根據以上廠家(jia)所(suo)提供的蓄電池參(can)數， 參(can)照(zhao)UC3909 芯(xin)片資(zi)料(liao)及(ji)相關參(can)考(kao)文獻(xian)，計(ji)算(suan)U C3909 外圍元件參(can)數， R S1、RS2 、RS3、RS4計(ji)算(suan)公(gong)式如下(xia)：

　　式中(zhong)， UREF 為UC3909 內部基(ji)準電(dian)壓2. 3 V.代(dai)入相(xiang)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(liu)(liu)(liu)(liu)入(ru)U C3909 內部(bu)電(dian)(dian)流(liu)(liu)(liu)(liu)誤(wu)差放大器反向輸(shu)出端CA 的固定控制電(dian)(dian)流(liu)(liu)(liu)(liu)ITRCK 、涓流(liu)(liu)(liu)(liu)充電(dian)(dian)電(dian)(dian)流(liu)(liu)(liu)(liu)I T 、恒流(liu)(liu)(liu)(liu)充電(dian)(dian)電(dian)(dian)流(liu)(liu)(liu)(liu)IBULK及過充終止電(dian)(dian)流(liu)(liu)(liu)(liu)IOCT 計(ji)算(suan)得出RG1、RG2 , R OVC1和ROVC2 , 其基本計(ji)算(suan)公式如(ru)下(xia)：

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

ROVC1和(he)R OVC2滿足(zu)以下關系式:

　　最終ROVC1和ROVC2 分別選(xuan)取為1 k Ω  , 10 kΩ