近年來(lai)隨著能(neng)(neng)源(yuan)短缺問題日(ri)益突(tu)出， 太(tai)陽(yang)能(neng)(neng)、風能(neng)(neng)等新型無污(wu)染的替代(dai)能(neng)(neng)源(yuan)應用日(ri)益受(shou)到(dao)重視。獨立(li)型太(tai)陽(yang)能(neng)(neng)照明系統因其結構簡單、無需(xu)鋪(pu)設電纜， 且搭建、攜帶(dai)較為方便等特點在照明領域有著廣(guang)泛應用前景(jing)。

　　但目前急需解決的(de)(de)(de)有鉛酸(suan)(suan)蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)使(shi)(shi)(shi)用壽(shou)命較短及系(xi)(xi)統(tong)在弱(ruo)(ruo)光(guang)(guang)(guang)條件下(xia)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)能(neng)(neng)力(li)不(bu)(bu)足這兩(liang)大(da)問題(ti)。系(xi)(xi)統(tong)儲能(neng)(neng)元件鉛酸(suan)(suan)蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)設計壽(shou)命約三(san)年(nian)， 但由于充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)方(fang)式、存儲方(fang)式以(yi)及人為等諸(zhu)多因素(su)的(de)(de)(de)影響導致(zhi)其使(shi)(shi)(shi)用壽(shou)命過短，需要(yao)經(jing)常更換， 不(bu)(bu)僅(jin)加大(da)了(le)使(shi)(shi)(shi)用成本(ben)(ben)也影響了(le)系(xi)(xi)統(tong)的(de)(de)(de)穩定性。另外大(da)部分已使(shi)(shi)(shi)用的(de)(de)(de)系(xi)(xi)統(tong)在弱(ruo)(ruo)光(guang)(guang)(guang)條件下(xia)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)能(neng)(neng)力(li)不(bu)(bu)足， 導致(zhi)系(xi)(xi)統(tong)太陽(yang)能(neng)(neng)板利用率不(bu)(bu)高(gao)； 傳統(tong)提(ti)高(gao)弱(ruo)(ruo)光(guang)(guang)(guang)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)能(neng)(neng)力(li)的(de)(de)(de)方(fang)法是采(cai)用組(zu)(zu)(zu)態(tai)優化控(kong)制(zhi)來實(shi)現， 即根據外界光(guang)(guang)(guang)照強(qiang)弱(ruo)(ruo)采(cai)用繼(ji)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)器控(kong)制(zhi)太陽(yang)能(neng)(neng)板組(zu)(zu)(zu)件按照串聯(lian)或并(bing)(bing)聯(lian)等不(bu)(bu)同的(de)(de)(de)組(zu)(zu)(zu)合方(fang)式給蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)， 確保太陽(yang)能(neng)(neng)板組(zu)(zu)(zu)件輸(shu)出電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)始(shi)終達(da)到設定充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)。這種(zhong)方(fang)法雖然可以(yi)實(shi)現弱(ruo)(ruo)光(guang)(guang)(guang)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)， 但在組(zu)(zu)(zu)態(tai)變(bian)化的(de)(de)(de)瞬間， 電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)輸(shu)出電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)波動較大(da)， 影響系(xi)(xi)統(tong)穩定性。此外， 由于采(cai)用繼(ji)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)器控(kong)制(zhi)， 繼(ji)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)器的(de)(de)(de)機械開關觸點在工作(zuo)較長(chang)時間后容易磨(mo)損失(shi)靈甚至引(yin)起誤操作(zuo)。為了(le)有效(xiao)提(ti)高(gao)系(xi)(xi)統(tong)弱(ruo)(ruo)光(guang)(guang)(guang)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)能(neng)(neng)力(li)， 本(ben)(ben)文采(cai)用超級電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容器組(zu)(zu)(zu)及升降(jiang)壓(ya)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)來實(shi)現弱(ruo)(ruo)光(guang)(guang)(guang)條件下(xia)有效(xiao)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)， 并(bing)(bing)采(cai)用UC3909 實(shi)現對膠體密封鉛酸(suan)(suan)蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)智能(neng)(neng)化充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)管(guan)理， 延長(chang)蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)使(shi)(shi)(shi)用壽(shou)命。

　　1  鉛酸蓄電池充電特性

　　鉛酸(suan)蓄電(dian)池的充電(dian)特(te)(te)性是由其最大接受充電(dian)能力來體現， 是在(zai)保證蓄電(dian)池析氣率較(jiao)低(di)、溫升(sheng)較(jiao)低(di)時所(suo)能承(cheng)受的最大充電(dian)電(dian)流。其充電(dian)特(te)(te)性曲線方程式為：

       式(shi)中， I 為充(chong)電(dian)(dian)電(dian)(dian)流(liu)； I 0為初(chu)始最(zui)大充(chong)電(dian)(dian)電(dian)(dian)流(liu)； a 為最(zui)大接受力比(bi)； t 為充(chong)電(dian)(dian)時間(jian)。

　　在實際的(de)電(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)電(dian)(dian)(dian)管(guan)理過程(cheng)中， 要使蓄電(dian)(dian)(dian)池(chi)的(de)充(chong)(chong)(chong)電(dian)(dian)(dian)過程(cheng)完(wan)全吻合(he)該(gai)充(chong)(chong)(chong)電(dian)(dian)(dian)特(te)性曲(qu)線(xian)存在較大困難(nan)。因此本著提高(gao)充(chong)(chong)(chong)電(dian)(dian)(dian)效(xiao)率、保(bao)障蓄電(dian)(dian)(dian)池(chi)使用(yong)壽命(ming)、實現(xian)合(he)理有(you)效(xiao)充(chong)(chong)(chong)電(dian)(dian)(dian)的(de)原(yuan)則，           參考充(chong)(chong)(chong)電(dian)(dian)(dian)特(te)性曲(qu)線(xian)， 采(cai)用(yong)智能控(kong)制芯片(pian)UC3909 實現(xian)對膠體密封鉛酸(suan)蓄電(dian)(dian)(dian)池(chi)分(fen)段充(chong)(chong)(chong)放電(dian)(dian)(dian)控(kong)制管(guan)理。

　　2  基于UC3909 控制器的四階段充電

　　目前(qian)獨立型太陽能(neng)照明系(xi)統中蓄(xu)電(dian)(dian)池(chi)(chi)充(chong)(chong)(chong)(chong)電(dian)(dian)控制器一般(ban)采用(yong)的(de)(de)(de)(de)是三階(jie)段(duan)充(chong)(chong)(chong)(chong)電(dian)(dian)方式，即先(xian)恒(heng)(heng)流(liu)充(chong)(chong)(chong)(chong)電(dian)(dian)、再恒(heng)(heng)壓充(chong)(chong)(chong)(chong)電(dian)(dian)、后浮充(chong)(chong)(chong)(chong)充(chong)(chong)(chong)(chong)電(dian)(dian)。但由于某些應用(yong)場合的(de)(de)(de)(de)蓄(xu)電(dian)(dian)池(chi)(chi)會經(jing)常(chang)出現過度放電(dian)(dian)的(de)(de)(de)(de)情況， 如(ru)果一開(kai)始(shi)就(jiu)直接(jie)進(jin)入較大電(dian)(dian)流(liu)充(chong)(chong)(chong)(chong)電(dian)(dian)的(de)(de)(de)(de)恒(heng)(heng)流(liu)充(chong)(chong)(chong)(chong)電(dian)(dian)階(jie)段(duan)， 容易(yi)(yi)造成(cheng)熱失控， 易(yi)(yi)損(sun)壞蓄(xu)電(dian)(dian)池(chi)(chi)。所以在(zai)最開(kai)始(shi)的(de)(de)(de)(de)時(shi)(shi)候應該(gai)采用(yong)小電(dian)(dian)流(liu)IT 充(chong)(chong)(chong)(chong)電(dian)(dian)的(de)(de)(de)(de)涓流(liu)充(chong)(chong)(chong)(chong)電(dian)(dian)模式， 等蓄(xu)電(dian)(dian)池(chi)(chi)的(de)(de)(de)(de)端電(dian)(dian)壓達到設定的(de)(de)(de)(de)充(chong)(chong)(chong)(chong)電(dian)(dian)使能(neng)電(dian)(dian)壓UT 時(shi)(shi)， 再進(jin)行恒(heng)(heng)流(liu)充(chong)(chong)(chong)(chong)電(dian)(dian)。UC3909 芯片(pian)可以根據蓄(xu)電(dian)(dian)池(chi)(chi)的(de)(de)(de)(de)狀(zhuang)態實(shi)現涓流(liu)充(chong)(chong)(chong)(chong)電(dian)(dian)、恒(heng)(heng)流(liu)充(chong)(chong)(chong)(chong)電(dian)(dian)、恒(heng)(heng)壓充(chong)(chong)(chong)(chong)電(dian)(dian)和浮充(chong)(chong)(chong)(chong)充(chong)(chong)(chong)(chong)電(dian)(dian)四個(ge)階(jie)段(duan)合理充(chong)(chong)(chong)(chong)電(dian)(dian)， 如(ru)圖1 所示(shi)。

                                                                 ;                        圖1  UC3909 的四階段充電曲線

　　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(gong)很小(xiao)的涓(juan)流(liu)IT 進(jin)行充電(dian)， IT 一般(ban)約為(wei)0. 01C（ C 為(wei)蓄電(dian)池容量）狀態2: 恒(heng)流(liu)充電(dian)。

　　當蓄電(dian)(dian)(dian)(dian)(dian)(dian)池的(de)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)達(da)到充電(dian)(dian)(dian)(dian)(dian)(dian)使能電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)UT 時， 充電(dian)(dian)(dian)(dian)(dian)(dian)器提供一個(ge)大電(dian)(dian)(dian)(dian)(dian)(dian)流I BULK 對蓄電(dian)(dian)(dian)(dian)(dian)(dian)池進行恒流充電(dian)(dian)(dian)(dian)(dian)(dian)， 這(zhe)一階(jie)段(duan)是充電(dian)(dian)(dian)(dian)(dian)(dian)的(de)主要階(jie)段(duan)， 蓄電(dian)(dian)(dian)(dian)(dian)(dian)池端電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)上升很快(kuai)， 直至電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)上升到過(guo)壓(ya)(ya)(ya)充電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)UOC 時進入恒壓(ya)(ya)(ya)充電(dian)(dian)(dian)(dian)(dian)(dian)階(jie)段(duan)。

　　狀態3: 恒壓充電。

　　在此(ci)階段， 充電(dian)器提供一個(ge)略高于(yu)蓄(xu)電(dian)池額(e)定值(zhi)的電(dian)壓UOC進行(xing)恒(heng)壓充電(dian)， 電(dian)路的充電(dian)電(dian)流(liu)將按指數規(gui)律逐(zhu)漸減小(xiao)， 直至(zhi)電(dian)流(liu)大小(xiao)等于(yu)充電(dian)終(zhong)止電(dian)流(liu)I OCT（約為10 % IBULK ） , 蓄(xu)電(dian)池已被充滿， 充電(dian)器進入浮充充電(dian)狀態(tai)。

　　狀態4: 浮充充電。

　　浮(fu)充(chong)(chong)(chong)(chong)充(chong)(chong)(chong)(chong)電階段， 充(chong)(chong)(chong)(chong)電器(qi)提供(gong)浮(fu)充(chong)(chong)(chong)(chong)電壓(ya)UF 對蓄電池(chi)以(yi)很(hen)小的(de)浮(fu)充(chong)(chong)(chong)(chong)電流進(jin)行充(chong)(chong)(chong)(chong)電， 以(yi)彌補(bu)蓄電池(chi)自放電造成的(de)容(rong)量損失。同時由于蓄電池(chi)的(de)浮(fu)充(chong)(chong)(chong)(chong)電壓(ya)隨溫(wen)度(du)(du)變化而變化， 因此(ci)需要選擇與蓄電池(chi)相同溫(wen)度(du)(du)系數的(de)熱敏電阻進(jin)行溫(wen)度(du)(du)補(bu)償， 確保在(zai)任何溫(wen)度(du)(du)下都能以(yi)精確的(de)浮(fu)充(chong)(chong)(chong)(chong)電壓(ya)進(jin)行浮(fu)充(chong)(chong)(chong)(chong)充(chong)(chong)(chong)(chong)電。溫(wen)度(du)(du)系數一般選擇- 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)(dian)路框圖， 光(guang)(guang)伏陣(zhen)列經(jing)過電(dian)(dian)壓(ya)電(dian)(dian)流采樣(yang)再經(jing)模(mo)數轉(zhuan)換將數字信號反饋至單(dan)片機(ji)， 單(dan)片機(ji)根(gen)據(ju)光(guang)(guang)伏陣(zhen)列的工作狀況輸出PWM 信號去驅動PMOS 管， 實(shi)(shi)現(xian)對光(guang)(guang)伏陣(zhen)列的最大功率跟蹤。超(chao)(chao)級(ji)(ji)電(dian)(dian)容器組、DC/ DC 變(bian)(bian)換器、UC3909 用來實(shi)(shi)現(xian)對閥(fa)控(kong)鉛酸(suan)蓄(xu)電(dian)(dian)池(chi)的四階段充(chong)電(dian)(dian)控(kong)制(zhi)， 并利用超(chao)(chao)級(ji)(ji)電(dian)(dian)容的特性優化(hua)充(chong)放(fang)電(dian)(dian)過程。本文側重對超(chao)(chao)級(ji)(ji)電(dian)(dian)容器組、U C3909 及DC/ DC 變(bian)(bian)換器等部分(fen)實(shi)(shi)現(xian)對閥(fa)控(kong)鉛酸(suan)蓄(xu)電(dian)(dian)池(chi)四階段的充(chong)電(dian)(dian)分(fen)析及設(she)計。

圖(tu)2  系統(tong)框(kuang)圖(tu)

　　3. 1  UC3909 充電器主要參數設(she)計(ji)

　　基于UC3909 的(de)充(chong)放電電路如圖(tu)3 所示。

      圖3  基于UC3909的(de)充(chong)放電電路

　　根(gen)(gen)據UC3909 內(nei)部集成(cheng)電(dian)(dian)(dian)(dian)(dian)路(lu)及光(guang)伏陣列、超級電(dian)(dian)(dian)(dian)(dian)容參數并結合(he)閥(fa)控鉛酸蓄電(dian)(dian)(dian)(dian)(dian)池的(de)(de)容量及額定電(dian)(dian)(dian)(dian)(dian)壓等參數對電(dian)(dian)(dian)(dian)(dian)路(lu)各個部分進行合(he)理計算設計。本設計使用賽特公司(si)生產(chan)的(de)(de)12 V, 65 Ah膠體(ti)密封鉛酸蓄電(dian)(dian)(dian)(dian)(dian)池， 根(gen)(gen)據廠家提供的(de)(de)蓄電(dian)(dian)(dian)(dian)(dian)池充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)參數， 浮充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)壓UF 取(qu)(qu)13. 8 V,充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)使能(neng)電(dian)(dian)(dian)(dian)(dian)壓UT 取(qu)(qu)10. 8 V; 過壓充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)壓UOC 14. 7V; 涓流(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)I TC 取(qu)(qu)0. 26 A; 恒流(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)I BU LK 取(qu)(qu)系統最大充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)6. 5 A; 過充(chong)(chong)終止電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)IOCT 取(qu)(qu)1 A.

　　根據以上廠(chang)家所提(ti)供的蓄(xu)電池參(can)數(shu)， 參(can)照UC3909 芯片資(zi)料及相關參(can)考文獻，計算(suan)U C3909 外圍(wei)元件(jian)參(can)數(shu)， R S1、RS2 、RS3、RS4計算(suan)公式(shi)如下：

　　式中， UREF 為(wei)UC3909 內部基準電(dian)壓2. 3 V.代入(ru)相關值計算得(de)（ R S1、RS2、RS3、RS4 分(fen)別為(wei)245 k Ω 、16 kΩ  、53kΩ 、975 kΩ 。

　　另(ling)外， 可以根據流(liu)(liu)入U C3909 內部電(dian)流(liu)(liu)誤差放(fang)大器反(fan)向輸出端CA 的固(gu)定控制電(dian)流(liu)(liu)ITRCK 、涓流(liu)(liu)充(chong)電(dian)電(dian)流(liu)(liu)I T 、恒(heng)流(liu)(liu)充(chong)電(dian)電(dian)流(liu)(liu)IBULK及過充(chong)終止電(dian)流(liu)(liu)IOCT 計(ji)算(suan)得出RG1、RG2 , R OVC1和ROVC2 , 其基本(ben)計(ji)算(suan)公式如下：

 　　RSET 取11. 5 k  , 電流采樣電阻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(he)ROVC2 分別選取為1 k Ω  , 10 kΩ