電動車(che)充電器的(de)有(you)關(guan)知(zhi)識

 

 

充電器的分類：用有、無工頻(pin)（

50

赫茲）變壓器區分，可分為兩大類。貨(huo)運三輪充電器一(yi)

般使(shi)用(yong)帶工頻變(bian)壓器(qi)的充電(dian)機，體積大、重量大，費電(dian)，但是可靠，便宜；電(dian)動自行車和電(dian)

摩則使用所謂開關電(dian)源式充(chong)電(dian)器，省電(dian)，效率高，但(dan)是易壞。

 

 

 

 

 

開關電(dian)源式充(chong)電(dian)器的正確操作是(shi)：

充電時，

先插電池，

后加市電；

充足后，

先切斷市電，

后拔(ba)電池插(cha)頭(tou)。如(ru)果(guo)在充電時先拔(ba)電池插(cha)頭(tou)，特別是充電電流大（紅燈）時，非常容易損壞

充電器。

 

 

 

 

 

 

 

常(chang)用的開關電源式充電器又分(fen)半橋式和單激式兩大(da)類，

單(dan)激類又分為正激式和反激式

兩類。半橋(qiao)式(shi)成(cheng)本高(gao)，性能好，常用于帶負脈沖的(de)充電器；單激式(shi)成(cheng)本低，市(shi)場占(zhan)有率高(gao)。

 

 

 

 

 

 

 

關于負脈沖充電器

 

 

 

 

 

 

 

鉛酸電池已經有

100

多年的歷史了，

開始(shi)全球普(pu)遍沿引老的(de)觀點和操作規程：

充、

放

電率為

0.1C(C

是電池容量

)

壽命較長。

美國(guo)人(ren)麥斯先生為解決快速充電問題，

1967

年向全世

界公(gong)布了他(ta)的研究成果，用大于

1C

率脈沖電(dian)流充(chong)電(dian)，充(chong)電(dian)間歇時對(dui)電(dian)池(chi)放(fang)電(dian)。放(fang)電(dian)有利于

消除(chu)極化、降低電解(jie)液溫度、提(ti)高極板(ban)接受電荷的能力。

 

 

 

 

 

 

 

我國(guo)一些科(ke)技(ji)工作(zuo)者在(zai)

1969

年前(qian)后(hou)，根據麥斯先(xian)生的三定律制(zhi)作(zuo)成功了多種品牌的

快速充電機。

充電循環過程是：

大(da)電(dian)流脈沖充電(dian)→切斷充電(dian)通路(lu)→對電(dian)池(chi)短暫放電(dian)→停(ting)止(zhi)放

電(dian)→接通充電(dian)通路→大電(dian)流脈沖充電(dian)??

 

 

 

 

 

 

 

 

2000

年前后，有人(ren)將這一原理用到了(le)電動車充電器(qi)中，充電過(guo)程中，不切斷充電通

路，用(yong)小電阻將電池(chi)短路瞬(shun)間，

進行放電(dian)(dian)。短(duan)路時由(you)于不切斷充(chong)電(dian)(dian)通(tong)路，在充(chong)電(dian)(dian)通(tong)路中串連

了電感。一般在

1

秒內短路

3

－

5

毫秒（

1

秒＝

1000

毫秒）

，由于(yu)電感里的電流不能跳變，

短

路時間短促，

可(ke)以保護充(chong)電器的(de)電源轉換部(bu)分。

如果把充電(dian)電(dian)流方向叫(jiao)正(zheng)，

放電自然為負了，

電(dian)動(dong)車業(ye)就出現了名詞“負脈沖充(chong)電(dian)器”

，而且稱可以延長(chang)電池壽命等(deng)等(deng)。

 

 

 

 

 

 

 

關于三段式充電器

 

 

 

 

 

 

 

近幾年，

電動車普遍使用(yong)了所謂三段式充電器，

第一(yi)個階(jie)段叫恒流階(jie)段，

第二個階段

叫恒壓階段，

第三(san)個階段叫涓流(liu)階段。

從電子技術角度針(zhen)對電池而(er)言：

第一個階段叫充電限

流階段，

第二個(ge)階(jie)段叫高恒壓階(jie)段，

第三(san)個階(jie)段叫低恒(heng)壓階(jie)段比較貼(tie)切(qie)。

第二階段和第三階

段(duan)(duan)轉換(huan)時，面板(ban)指示燈(deng)相(xiang)應變換(huan)，大多數充電器第一、二階段(duan)(duan)是紅燈(deng)，第三階段(duan)(duan)變綠(lv)燈(deng)。第

二(er)階段和第(di)三階段的(de)相互(hu)轉換是由充電電流決定的(de)，

大于(yu)某電流進入第一(yi)第二階段，

小于某

電(dian)流進(jin)入(ru)第三階段。這個電(dian)流叫轉換電(dian)流，也叫轉折電(dian)流。

 

 

 

 

 

 

 

早期充電器，

包(bao)括(kuo)名牌車(che)配(pei)套(tao)的充電(dian)器，雖然(ran)也變燈，

但(dan)實際(ji)是恒壓限(xian)流(liu)充電(dian)器，并(bing)

不是三階(jie)段充電(dian)器(qi)。一般這類就一個穩定電(dian)壓值，

44.2V

左右，對當時的高比重硫酸(suan)的電池(chi)

還湊合。

 

 

 

 

 

 

 

關于三段式(shi)充電器的(de)三個關鍵(jian)參(can)數

 

 

 

 

 

 

 

第一個重要參數(shu)是(shi)涓流階段的低(di)恒壓值，

第二個重(zhong)要參數(shu)是第二階段的高恒(heng)壓值，

第

三個(ge)重(zhong)(zhong)要參(can)數是轉換電(dian)流。這(zhe)三個(ge)重(zhong)(zhong)要參(can)數與(yu)電(dian)池數目有關，與(yu)電(dian)池的容量

Ah

有關，與溫

度有(you)關，與電(dian)池(chi)種類有(you)關。為了方便大家記憶，下面以最常見的電(dian)動自行車（三(san)塊

12V

串

聯的

10Ah

電(dian)池）所用(yong)的三段式充電(dian)器為(wei)例簡單介紹一下：

 

 

 

 

 

 

 

 

首先討論涓流階(jie)段的低恒壓值，

參考電壓為

42.5V

左右。

此值(zhi)高將(jiang)使(shi)電池(chi)失水，

容易

使電(dian)池發(fa)熱變形；此值(zhi)(zhi)低不利于電(dian)池充足電(dian)。此值(zhi)(zhi)在南方(fang)要低于

41.5V

；膠體電池要低于

41.5V

，如在南方(fang)還要低一點(dian)兒。這(zhe)個參數是相對嚴格的，不可以大于參考值。

 

 

 

 

 

 

 

其次討論第二階(jie)段的高恒壓(ya)值，參考電(dian)壓(ya)為(wei)

44.5V

左右。此值高有利于快(kuai)速充足(zu)電，

但是容易(yi)使電池失水(shui)，

充(chong)電后(hou)期電流下(xia)不(bu)來，

結果使電池(chi)發熱變形(xing)；

此值低不利(li)于電池快(kuai)速

充足電，有(you)利于向涓流階段(duan)轉換。這個值雖(sui)然沒有(you)第一個值那樣嚴格，但是也不要(yao)過高。

 

 

 

 

 

 

 

最后討論轉換電流，

參考電流為

300

毫安左右。

此值高有利于電池壽命(ming)，

不容易發熱

本文介紹(shao)的(de)是有關鋰(li)電(dian)(dian)池組保(bao)護(hu)(hu)板均衡充電(dian)(dian)基(ji)本工作原理，在采用單(dan)節(jie)鋰(li)電(dian)(dian)池保(bao)護(hu)(hu)芯(xin)片設計的(de)且具(ju)備均衡充電(dian)(dian)能力(li)的(de)鋰(li)電(dian)(dian)池組保(bao)護(hu)(hu)板，示意圖(tu)如圖(tu)1所示。

其中：1為單節鋰離子電池；2為充電過電壓分流放電支路電阻；3 為分流放電支路控制用開關器件；4為過流檢測保護電阻；5為省略的鋰電池保護芯片及電路連接部分；6為單節鋰電池保護芯片(一般包括充電控制引腳CO,放電控制引腳DO，放電過電流及短路檢測引腳VM，電池正端VDD，電池負端VSS等)；7為充電過電壓保護信號經光耦隔離后形成并聯關系驅動主電路中充電控制用MOS管柵極；8為放電欠電壓、過流、短路保護信號經光耦隔離后形成串聯關系驅動主電路中放電控制用MOS管柵極；9為充電控制開關器件；10為放電控制開關器件；11為控制電路；12為主電路；13為分流放電支路。單節鋰電池保護芯片數目依據鋰電池組電(dian)(dian)池(chi)(chi)數目確定，串聯使用，分別對(dui)所對(dui)應(ying)單節鋰(li)電(dian)(dian)池(chi)(chi)的充(chong)放(fang)電(dian)(dian)、過流(liu)、短路(lu)狀態進行保(bao)(bao)護。該(gai)系統在(zai)(zai)充(chong)電(dian)(dian)保(bao)(bao)護的同(tong)時，通過保(bao)(bao)護芯片控制(zhi)分流(liu)放(fang)電(dian)(dian)支(zhi)路(lu)開關器件的通斷實現均(jun)衡充(chong)電(dian)(dian)，該(gai)方案有別于(yu)傳統的在(zai)(zai)充(chong)電(dian)(dian)器端(duan)實現均(jun)衡充(chong)電(dian)(dian)的做法，降低了鋰(li)電(dian)(dian)池(chi)(chi)組充(chong)電(dian)(dian)器設計應(ying)用的成本。

圖(tu)1 具備均衡充電(dian)能力的鋰電(dian)池組保護板示意(yi)圖(tu)

當鋰電池組充電時，外接電源正負極分別接電池組正負極BAT+和BAT-兩端，充電電流流經電池組正極BAT+、電池組中單節鋰電池1～N、放電控制開關器件、充電控制開關器件、電池組負極BAT-,電流流向如圖2所示。
圖2 充電過程
系統中控制電路部分單節鋰電池保護芯片的充電過電壓保護控制信號經光耦隔離后并聯輸出，為主電路中充電開關器件的導通提供柵極電壓；如某一節或幾節鋰電池在充電過程中先進入過電壓保護狀態，則由過電壓保護信號控制并聯在單節鋰電池正負極(ji)兩端的(de)分流放(fang)電支路放(fang)電，同時將串接在充電回(hui)路中(zhong)的(de)對應單體鋰(li)電池斷(duan)離出充電回(hui)路。

鋰電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)組串聯充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)時(shi)，忽略單節(jie)(jie)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)容量(liang)差(cha)別的(de)(de)影響，一般(ban)內(nei)阻較小(xiao)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)先(xian)充(chong)滿(man)(man)。此(ci)時(shi)，相應的(de)(de)過(guo)(guo)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)保(bao)(bao)護信號控制分(fen)(fen)(fen)流放電(dian)(dian)(dian)(dian)(dian)(dian)支(zhi)路(lu)(lu)的(de)(de)開(kai)關(guan)器件(jian)閉合，在原電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)兩端并(bing)聯上一個分(fen)(fen)(fen)流電(dian)(dian)(dian)(dian)(dian)(dian)阻。根據(ju)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)(de)PNGV等效電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)模(mo)型，此(ci)時(shi)分(fen)(fen)(fen)流支(zhi)路(lu)(lu)電(dian)(dian)(dian)(dian)(dian)(dian)阻相當于先(xian)充(chong)滿(man)(man)的(de)(de)單節(jie)(jie)鋰電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)(de)負載(zai)，該電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)通過(guo)(guo)其(qi)放電(dian)(dian)(dian)(dian)(dian)(dian)，使(shi)(shi)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)端電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)維持(chi)在充(chong)滿(man)(man)狀態附(fu)近一個極(ji)小(xiao)的(de)(de)范圍內(nei)。假設第1節(jie)(jie)鋰電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)先(xian)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)完成，進入(ru)過(guo)(guo)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)保(bao)(bao)護狀態，則主(zhu)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)及分(fen)(fen)(fen)流放電(dian)(dian)(dian)(dian)(dian)(dian)支(zhi)路(lu)(lu)中電(dian)(dian)(dian)(dian)(dian)(dian)流流向如(ru)圖3所示(shi)。當所有單節(jie)(jie)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)均(jun)(jun)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)進入(ru)過(guo)(guo)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)保(bao)(bao)護狀態時(shi)，全部(bu)單節(jie)(jie)鋰電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)大小(xiao)在誤差(cha)范圍內(nei)完全相等，各節(jie)(jie)保(bao)(bao)護芯片充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)保(bao)(bao)護控制信號均(jun)(jun)變低，無法為(wei)主(zhu)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)(lu)中的(de)(de)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)控制開(kai)關(guan)器件(jian)提供(gong)柵極(ji)偏(pian)壓(ya)，使(shi)(shi)其(qi)關(guan)斷，主(zhu)回(hui)路(lu)(lu)斷開(kai)，即實現均(jun)(jun)衡充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)，充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)過(guo)(guo)程(cheng)完成。

圖3 分流均衡過程

當電(dian)(dian)(dian)池(chi)組(zu)放電(dian)(dian)(dian)時，外(wai)接負(fu)載分(fen)別(bie)接電(dian)(dian)(dian)池(chi)組(zu)正負(fu)極(ji)BAT+和BAT-兩(liang)端，放電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)流(liu)(liu)經電(dian)(dian)(dian)池(chi)組(zu)負(fu)極(ji)BAT-、充電(dian)(dian)(dian)控(kong)制(zhi)開(kai)(kai)(kai)關器(qi)件(jian)、放電(dian)(dian)(dian)控(kong)制(zhi)開(kai)(kai)(kai)關器(qi)件(jian)、電(dian)(dian)(dian)池(chi)組(zu)中單節(jie)鋰電(dian)(dian)(dian)池(chi)N～1和電(dian)(dian)(dian)池(chi)組(zu)正極(ji)BAT+,電(dian)(dian)(dian)流(liu)(liu)流(liu)(liu)向如圖4所示。系統中控(kong)制(zhi)電(dian)(dian)(dian)路(lu)(lu)部分(fen)單節(jie)鋰電(dian)(dian)(dian)池(chi)保護芯片的放電(dian)(dian)(dian)欠電(dian)(dian)(dian)壓(ya)保護、過流(liu)(liu)和短(duan)路(lu)(lu)保護控(kong)制(zhi)信(xin)號經光耦(ou)隔(ge)離后(hou)串聯輸(shu)出，為主電(dian)(dian)(dian)路(lu)(lu)中放電(dian)(dian)(dian)開(kai)(kai)(kai)關器(qi)件(jian)的導(dao)通(tong)提供柵(zha)(zha)極(ji)電(dian)(dian)(dian)壓(ya);一旦電(dian)(dian)(dian)池(chi)組(zu)在放電(dian)(dian)(dian)過程中遇到單節(jie)鋰電(dian)(dian)(dian)池(chi)欠電(dian)(dian)(dian)壓(ya)或者過流(liu)(liu)和短(duan)路(lu)(lu)等特殊情(qing)況(kuang)，對應的單節(jie)鋰電(dian)(dian)(dian)池(chi)放電(dian)(dian)(dian)保護控(kong)制(zhi)信(xin)號變(bian)低，無法為主電(dian)(dian)(dian)路(lu)(lu)中的放電(dian)(dian)(dian)控(kong)制(zhi)開(kai)(kai)(kai)關器(qi)件(jian)提供柵(zha)(zha)極(ji)偏壓(ya)，使(shi)其關斷，主回路(lu)(lu)斷開(kai)(kai)(kai)，即結束放電(dian)(dian)(dian)使(shi)用過程。

圖4 放電過程

一般鋰電(dian)(dian)池采用(yong)恒流-恒壓(ya)(TAPER)型充電(dian)(dian)控制(zhi)，恒壓(ya)充電(dian)(dian)時，充電(dian)(dian)電(dian)(dian)流近(jin)似指(zhi)數規律減小。系統中(zhong)充放電(dian)(dian)主(zhu)回路(lu)的開關器件可根(gen)據外部(bu)電(dian)(dian)路(lu)要(yao)求(qiu)滿足的最大(da)工作電(dian)(dian)流和工作電(dian)(dian)壓(ya)選型。

控制電路的單節(jie)鋰(li)電池(chi)保護芯片可根據待保護的單節(jie)鋰(li)電池(chi)的電壓(ya)等級、保護延遲時間(jian)等選型(xing)。

單節電池兩端并接的放電支路電阻可根據鋰電池充電器的(de)充電(dian)電(dian)壓大(da)小(xiao)以及(ji)鋰(li)電(dian)池的(de)參數和放電(dian)電(dian)流的(de)大(da)小(xiao)計(ji)算得出。均(jun)衡(heng)電(dian)流應合理選擇(ze)，如果(guo)太小(xiao)，均(jun)衡(heng)效(xiao)果(guo)不明顯；如果(guo)太大(da)，系統的(de)能量(liang)損耗大(da)，均(jun)衡(heng)效(xiao)率低，對鋰(li)電(dian)池組熱(re)管(guan)理要求高，一般電(dian)流大(da)小(xiao)可(ke)設計(ji)在50～100mA之間。

分(fen)流(liu)放電(dian)(dian)(dian)(dian)支路(lu)電(dian)(dian)(dian)(dian)阻(zu)可(ke)采(cai)用功(gong)率電(dian)(dian)(dian)(dian)阻(zu)或(huo)電(dian)(dian)(dian)(dian)阻(zu)網絡實現。這里(li)采(cai)用電(dian)(dian)(dian)(dian)阻(zu)網絡實現分(fen)流(liu)放電(dian)(dian)(dian)(dian)支路(lu)電(dian)(dian)(dian)(dian)阻(zu)較為合理，可(ke)以有效消除電(dian)(dian)(dian)(dian)阻(zu)偏差的影(ying)響，此外，還能起到降低熱功(gong)耗(hao)的作用。