近(jin)年(nian)來(lai)隨著能(neng)(neng)源(yuan)短缺(que)問題日(ri)益(yi)突出， 太陽能(neng)(neng)、風能(neng)(neng)等新型無污染的替代能(neng)(neng)源(yuan)應用(yong)日(ri)益(yi)受到(dao)重視。獨立型太陽能(neng)(neng)照(zhao)明(ming)系統因其結構簡單、無需鋪設電纜， 且搭建、攜帶較為(wei)方便等特點(dian)在(zai)照(zhao)明(ming)領域(yu)有(you)著廣泛應用(yong)前(qian)景(jing)。

　　但目前急需解決的(de)(de)(de)有(you)(you)鉛(qian)(qian)酸蓄(xu)電(dian)池使(shi)用(yong)壽(shou)命(ming)較(jiao)短及(ji)系(xi)(xi)統(tong)在弱光條件(jian)(jian)下(xia)(xia)充電(dian)能(neng)力(li)不足這(zhe)兩大問題。系(xi)(xi)統(tong)儲能(neng)元件(jian)(jian)鉛(qian)(qian)酸蓄(xu)電(dian)池設計壽(shou)命(ming)約三年， 但由(you)于(yu)充電(dian)方式、存儲方式以及(ji)人為等諸多因素的(de)(de)(de)影(ying)(ying)響導致(zhi)其使(shi)用(yong)壽(shou)命(ming)過短，需要經常更換， 不僅加大了(le)使(shi)用(yong)成(cheng)本也(ye)影(ying)(ying)響了(le)系(xi)(xi)統(tong)的(de)(de)(de)穩(wen)(wen)定(ding)性。另外大部分已(yi)使(shi)用(yong)的(de)(de)(de)系(xi)(xi)統(tong)在弱光條件(jian)(jian)下(xia)(xia)充電(dian)能(neng)力(li)不足， 導致(zhi)系(xi)(xi)統(tong)太陽(yang)能(neng)板(ban)利用(yong)率不高(gao)； 傳(chuan)統(tong)提高(gao)弱光充電(dian)能(neng)力(li)的(de)(de)(de)方法是(shi)采用(yong)組態(tai)優(you)化控(kong)制(zhi)來(lai)實(shi)現， 即根據外界光照(zhao)強弱采用(yong)繼電(dian)器控(kong)制(zhi)太陽(yang)能(neng)板(ban)組件(jian)(jian)按照(zhao)串聯或并聯等不同(tong)的(de)(de)(de)組合方式給(gei)蓄(xu)電(dian)池充電(dian)， 確保太陽(yang)能(neng)板(ban)組件(jian)(jian)輸(shu)出電(dian)壓始終達到設定(ding)充電(dian)電(dian)壓。這(zhe)種方法雖然可以實(shi)現弱光充電(dian)， 但在組態(tai)變(bian)化的(de)(de)(de)瞬間， 電(dian)路輸(shu)出電(dian)壓波動較(jiao)大， 影(ying)(ying)響系(xi)(xi)統(tong)穩(wen)(wen)定(ding)性。此(ci)外， 由(you)于(yu)采用(yong)繼電(dian)器控(kong)制(zhi)， 繼電(dian)器的(de)(de)(de)機(ji)械(xie)開關觸點在工作較(jiao)長時間后(hou)容易(yi)磨損失靈甚(shen)至引起誤操作。為了(le)有(you)(you)效提高(gao)系(xi)(xi)統(tong)弱光充電(dian)能(neng)力(li)， 本文采用(yong)超級電(dian)容器組及(ji)升降(jiang)壓電(dian)路來(lai)實(shi)現弱光條件(jian)(jian)下(xia)(xia)有(you)(you)效充電(dian)， 并采用(yong)UC3909 實(shi)現對膠體密(mi)封鉛(qian)(qian)酸蓄(xu)電(dian)池智能(neng)化充電(dian)管(guan)理， 延(yan)長蓄(xu)電(dian)池使(shi)用(yong)壽(shou)命(ming)。

　　1  鉛酸蓄電池充電特性

　　鉛酸蓄(xu)(xu)電(dian)(dian)池的充電(dian)(dian)特性是由其最大(da)接受(shou)充電(dian)(dian)能力(li)來體現(xian)， 是在保(bao)證蓄(xu)(xu)電(dian)(dian)池析(xi)氣率較低、溫(wen)升較低時(shi)所(suo)能承受(shou)的最大(da)充電(dian)(dian)電(dian)(dian)流。其充電(dian)(dian)特性曲線(xian)方程式(shi)為：

       式中， I 為(wei)充(chong)(chong)電(dian)電(dian)流； I 0為(wei)初始最(zui)大充(chong)(chong)電(dian)電(dian)流； a 為(wei)最(zui)大接受力比； t 為(wei)充(chong)(chong)電(dian)時間(jian)。

　　在(zai)(zai)實際的(de)電池(chi)充(chong)(chong)電管(guan)理過程中， 要使(shi)(shi)蓄電池(chi)的(de)充(chong)(chong)電過程完全吻(wen)合該充(chong)(chong)電特(te)(te)性曲線存(cun)在(zai)(zai)較大困難。因此本著(zhu)提高充(chong)(chong)電效率、保障蓄電池(chi)使(shi)(shi)用壽命、實現(xian)合理有效充(chong)(chong)電的(de)原則(ze)，           參考充(chong)(chong)電特(te)(te)性曲線， 采用智能控制芯片UC3909 實現(xian)對膠(jiao)體密封(feng)鉛(qian)酸蓄電池(chi)分段充(chong)(chong)放電控制管(guan)理。

　　2  基于UC3909 控制器的四階段充電

　　目前獨(du)立型(xing)太(tai)陽(yang)能(neng)照明系(xi)統中蓄電(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)控制器一般采(cai)用的(de)(de)是三階段充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)方式(shi)，即(ji)先恒流(liu)(liu)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)、再恒壓(ya)(ya)(ya)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)、后浮充(chong)(chong)(chong)(chong)(chong)(chong)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)。但由于某些應用場(chang)合的(de)(de)蓄電(dian)(dian)(dian)(dian)(dian)池(chi)會經常出現(xian)過度放電(dian)(dian)(dian)(dian)(dian)的(de)(de)情況， 如果一開始就(jiu)直接進入較大電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)的(de)(de)恒流(liu)(liu)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)階段， 容易造成(cheng)熱(re)失控， 易損壞蓄電(dian)(dian)(dian)(dian)(dian)池(chi)。所以(yi)在最開始的(de)(de)時候應該(gai)采(cai)用小電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)IT 充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)的(de)(de)涓流(liu)(liu)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)模式(shi)， 等蓄電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)端(duan)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)達到(dao)設(she)定的(de)(de)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)使能(neng)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)UT 時， 再進行(xing)恒流(liu)(liu)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)。UC3909 芯片可以(yi)根據蓄電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)狀態實現(xian)涓流(liu)(liu)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)、恒流(liu)(liu)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)、恒壓(ya)(ya)(ya)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)和(he)浮充(chong)(chong)(chong)(chong)(chong)(chong)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)四個階段合理充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)， 如圖1 所示。

                                                                                         圖1  UC3909 的四(si)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IT 進行充(chong)電， IT 一般(ban)約為0. 01C（ C 為蓄(xu)電池(chi)容(rong)量）狀態2: 恒流充(chong)電。

　　當蓄(xu)電(dian)(dian)(dian)池的電(dian)(dian)(dian)壓(ya)(ya)達到充(chong)(chong)電(dian)(dian)(dian)使(shi)能電(dian)(dian)(dian)壓(ya)(ya)UT 時(shi)， 充(chong)(chong)電(dian)(dian)(dian)器提供(gong)一個大電(dian)(dian)(dian)流(liu)I BULK 對蓄(xu)電(dian)(dian)(dian)池進行恒流(liu)充(chong)(chong)電(dian)(dian)(dian)， 這(zhe)一階(jie)段是(shi)充(chong)(chong)電(dian)(dian)(dian)的主要階(jie)段， 蓄(xu)電(dian)(dian)(dian)池端電(dian)(dian)(dian)壓(ya)(ya)上升(sheng)很(hen)快(kuai)， 直至電(dian)(dian)(dian)壓(ya)(ya)上升(sheng)到過壓(ya)(ya)充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)壓(ya)(ya)UOC 時(shi)進入(ru)恒壓(ya)(ya)充(chong)(chong)電(dian)(dian)(dian)階(jie)段。

　　狀態3: 恒壓充電。

　　在此階段， 充(chong)(chong)電(dian)(dian)器(qi)提(ti)供(gong)一個略(lve)高于(yu)蓄電(dian)(dian)池額定值(zhi)的電(dian)(dian)壓(ya)UOC進行恒(heng)壓(ya)充(chong)(chong)電(dian)(dian)， 電(dian)(dian)路的充(chong)(chong)電(dian)(dian)電(dian)(dian)流(liu)將按指數規(gui)律(lv)逐漸減小， 直至電(dian)(dian)流(liu)大小等于(yu)充(chong)(chong)電(dian)(dian)終止電(dian)(dian)流(liu)I OCT（約為10 % IBULK ） , 蓄電(dian)(dian)池已被充(chong)(chong)滿， 充(chong)(chong)電(dian)(dian)器(qi)進入浮(fu)充(chong)(chong)充(chong)(chong)電(dian)(dian)狀(zhuang)態。

　　狀態4: 浮充充電。

　　浮(fu)(fu)充(chong)(chong)(chong)充(chong)(chong)(chong)電(dian)(dian)(dian)階段， 充(chong)(chong)(chong)電(dian)(dian)(dian)器提供浮(fu)(fu)充(chong)(chong)(chong)電(dian)(dian)(dian)壓(ya)(ya)UF 對蓄電(dian)(dian)(dian)池(chi)以很(hen)小的(de)浮(fu)(fu)充(chong)(chong)(chong)電(dian)(dian)(dian)流(liu)進(jin)行充(chong)(chong)(chong)電(dian)(dian)(dian)， 以彌補(bu)蓄電(dian)(dian)(dian)池(chi)自放電(dian)(dian)(dian)造成的(de)容量損失(shi)。同(tong)時由于蓄電(dian)(dian)(dian)池(chi)的(de)浮(fu)(fu)充(chong)(chong)(chong)電(dian)(dian)(dian)壓(ya)(ya)隨溫度(du)(du)(du)變(bian)化(hua)而變(bian)化(hua)， 因此需要選擇(ze)與蓄電(dian)(dian)(dian)池(chi)相同(tong)溫度(du)(du)(du)系(xi)數的(de)熱敏電(dian)(dian)(dian)阻進(jin)行溫度(du)(du)(du)補(bu)償， 確保在任(ren)何溫度(du)(du)(du)下都能以精確的(de)浮(fu)(fu)充(chong)(chong)(chong)電(dian)(dian)(dian)壓(ya)(ya)進(jin)行浮(fu)(fu)充(chong)(chong)(chong)充(chong)(chong)(chong)電(dian)(dian)(dian)。溫度(du)(du)(du)系(xi)數一般選擇(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路框圖， 光伏陣列(lie)經(jing)過電壓電流(liu)采(cai)樣(yang)再經(jing)模數(shu)轉(zhuan)換將(jiang)數(shu)字信(xin)號反饋至單(dan)片(pian)機， 單(dan)片(pian)機根據光伏陣列(lie)的(de)工作狀況輸出PWM 信(xin)號去驅動PMOS 管， 實現(xian)(xian)對(dui)(dui)光伏陣列(lie)的(de)最大功(gong)率跟蹤(zong)。超(chao)級電容器組(zu)、DC/ DC 變(bian)換器、UC3909 用來實現(xian)(xian)對(dui)(dui)閥控(kong)鉛(qian)酸蓄電池的(de)四階段充電控(kong)制， 并利用超(chao)級電容的(de)特性優化充放電過程。本(ben)文側重對(dui)(dui)超(chao)級電容器組(zu)、U C3909 及(ji)(ji)DC/ DC 變(bian)換器等部分實現(xian)(xian)對(dui)(dui)閥控(kong)鉛(qian)酸蓄電池四階段的(de)充電分析及(ji)(ji)設計。

圖2  系統框圖

　　3. 1  UC3909 充電器主要參(can)數設計

　　基于UC3909 的充放電電路(lu)如圖3 所示。

      圖3  基于UC3909的充放電(dian)電(dian)路

　　根據UC3909 內部集(ji)成電(dian)(dian)(dian)(dian)(dian)(dian)路及光伏陣(zhen)列(lie)、超(chao)級(ji)電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)參數(shu)(shu)并結合(he)閥控鉛(qian)酸(suan)蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)容(rong)量及額定電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)等參數(shu)(shu)對電(dian)(dian)(dian)(dian)(dian)(dian)路各(ge)個部分進行合(he)理計(ji)(ji)算(suan)設計(ji)(ji)。本設計(ji)(ji)使用(yong)賽特公司生產的(de)12 V, 65 Ah膠體密(mi)封鉛(qian)酸(suan)蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)， 根據廠(chang)家提供的(de)蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)參數(shu)(shu)， 浮充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)UF 取(qu)13. 8 V,充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)使能電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)UT 取(qu)10. 8 V; 過壓(ya)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)UOC 14. 7V; 涓(juan)流(liu)(liu)(liu)(liu)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)I TC 取(qu)0. 26 A; 恒(heng)流(liu)(liu)(liu)(liu)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)I BU LK 取(qu)系(xi)統最大充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)6. 5 A; 過充(chong)終止(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)IOCT 取(qu)1 A.

　　根據以上廠家所提(ti)供的蓄電(dian)池參數(shu)， 參照UC3909 芯(xin)片資(zi)料及相(xiang)關參考文(wen)獻，計算(suan)(suan)U C3909 外(wai)圍(wei)元件參數(shu)， R S1、RS2 、RS3、RS4計算(suan)(suan)公式如下(xia)：

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

　　另外， 可以(yi)根據流(liu)入U C3909 內部電(dian)(dian)(dian)流(liu)誤(wu)差放大器反向輸出端(duan)CA 的固(gu)定控制電(dian)(dian)(dian)流(liu)ITRCK 、涓流(liu)充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)I T 、恒流(liu)充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)IBULK及(ji)過充(chong)終止電(dian)(dian)(dian)流(liu)IOCT 計算得(de)出RG1、RG2 , R OVC1和ROVC2 , 其基本(ben)計算公(gong)式如下：

　　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(yi)下關系式(shi):

　　最終ROVC1和ROVC2 分別(bie)選取為1 k Ω  , 10 kΩ