電動車充(chong)電器(qi)的有關知(zhi)識(shi)

 

 

充電器的分類：用有、無(wu)工頻（

50

赫(he)茲）變(bian)壓(ya)器(qi)區分(fen)，可分(fen)為兩大類。貨運(yun)三(san)輪充電器(qi)一(yi)

般使用帶(dai)工頻變壓(ya)器的充電機，體積大(da)、重(zhong)量(liang)大(da)，費電，但(dan)是可(ke)靠，便宜(yi)；電動自行車和電

摩則使(shi)用(yong)所謂(wei)開關電(dian)源式充(chong)電(dian)器，省電(dian)，效率高，但是易壞。

 

 

 

 

 

開關(guan)電源式充電器(qi)的正確操作是：

充電時，

先插電池，

后加市電；

充足后，

先切斷市電，

后(hou)拔電池插頭(tou)。如果在充電時(shi)先拔電池插頭(tou)，特別(bie)是充電電流大(da)（紅燈）時(shi)，非(fei)常(chang)容(rong)易(yi)損(sun)壞

充電器。

 

 

 

 

 

 

 

常用(yong)的開關電源式充電器(qi)又(you)分半橋(qiao)式和單(dan)激(ji)式兩(liang)大(da)類，

單(dan)激類又分為正激式(shi)和反激式(shi)

兩類。半橋式成本高(gao)，性能好，常用于帶負(fu)脈沖的充(chong)電器；單激式成本低(di)，市(shi)場(chang)占有率高(gao)。

 

 

 

 

 

 

 

關于負脈沖充電器

 

 

 

 

 

 

 

鉛酸電池已經有

100

多年的歷史了，

開始全球普遍沿引(yin)老的觀點和操(cao)作規程(cheng)：

充、

放

電率為

0.1C(C

是電池容量

)

壽命較長。

美(mei)國人麥斯先生(sheng)為解(jie)決快速(su)充電(dian)問(wen)題(ti)，

1967

年向全世

界公布了他的(de)研究成果，用(yong)大于

1C

率脈沖電(dian)(dian)(dian)流充(chong)電(dian)(dian)(dian)，充(chong)電(dian)(dian)(dian)間歇時對電(dian)(dian)(dian)池放(fang)電(dian)(dian)(dian)。放(fang)電(dian)(dian)(dian)有(you)利于

消除極(ji)化、降(jiang)低(di)電解液溫度(du)、提高極(ji)板接受電荷(he)的(de)能力。

 

 

 

 

 

 

 

我國一(yi)些科技工作者在

1969

年前后，根(gen)據麥(mai)斯先(xian)生的(de)三定(ding)律制作成功了多種品(pin)牌的(de)

快速充電機。

充電循環過程是：

大(da)電流脈沖(chong)充(chong)電→切斷充(chong)電通路(lu)→對電池短暫放(fang)電→停止放(fang)

電(dian)→接通(tong)充電(dian)通(tong)路→大電(dian)流脈沖充電(dian)??

 

 

 

 

 

 

 

 

2000

年前后，有人將這一(yi)原理用到了(le)電動車(che)充電器中，充電過(guo)程中，不切(qie)斷充電通

路，用小電(dian)阻將電(dian)池短路瞬(shun)間，

進行(xing)放電。短路時由于不切斷充電通路，在充電通路中串連

了電感。一般在

1

秒內短路

3

－

5

毫秒（

1

秒＝

1000

毫秒）

，由于電(dian)感里的電(dian)流不能跳變，

短

路時間短促，

可以(yi)保護充(chong)電(dian)器的(de)電(dian)源(yuan)轉換部分(fen)。

如果把充電(dian)電(dian)流方向(xiang)叫正(zheng)，

放電自然為負了，

電(dian)動車(che)業就出現(xian)了名詞“負脈沖充電(dian)器”

，而且稱可以延長電池壽命等(deng)等(deng)。

 

 

 

 

 

 

 

關于三段式充電器

 

 

 

 

 

 

 

近幾年，

電動車(che)普遍使用(yong)了所謂三段(duan)式(shi)充電器，

第一個階段叫恒流階段，

第二個階段

叫恒壓階段，

第三個階(jie)(jie)段叫涓流階(jie)(jie)段。

從電(dian)子(zi)技術(shu)角(jiao)度針對電(dian)池(chi)而言：

第一個階段叫充電限

流階段，

第二個(ge)階段(duan)叫高恒壓階段(duan)，

第三個(ge)階段叫(jiao)低恒壓(ya)階段比較貼切。

第二階段和第三階

段轉換時(shi)，面板指(zhi)示(shi)燈相(xiang)應變(bian)換，大多(duo)數(shu)充電器(qi)第(di)(di)一、二(er)階段是(shi)紅燈，第(di)(di)三階段變(bian)綠燈。第(di)(di)

二(er)階段(duan)和第三階段(duan)的相互(hu)轉換是由充電電流決定的，

大于某(mou)電流進入第(di)一(yi)第(di)二(er)階段(duan)，

小于某

電(dian)流(liu)進入第三(san)階段(duan)。這個電(dian)流(liu)叫轉(zhuan)換電(dian)流(liu)，也叫轉(zhuan)折電(dian)流(liu)。

 

 

 

 

 

 

 

早期充電器，

包括名牌車配套的(de)充電器，雖然也(ye)變燈，

但實際(ji)是恒(heng)壓(ya)限流充電器(qi)，并

不是三階(jie)段充(chong)電器。一(yi)般這類就一(yi)個穩定電壓值，

44.2V

左右，對當時的高比重硫酸的電池

還湊合。

 

 

 

 

 

 

 

關于三(san)段式充電器的三(san)個(ge)關鍵參(can)數

 

 

 

 

 

 

 

第一個重要參數是涓流階段的(de)低恒(heng)壓值，

第二(er)個重要參數是第二(er)階(jie)段的高(gao)恒壓值，

第

三個(ge)重要(yao)參(can)數(shu)(shu)(shu)是轉換電流。這三個(ge)重要(yao)參(can)數(shu)(shu)(shu)與電池數(shu)(shu)(shu)目有關(guan)，與電池的容量(liang)

Ah

有關，與溫

度(du)有關，與電池種類有關。為了方(fang)便大家記憶，下(xia)面以(yi)最常(chang)見的(de)電動(dong)自行車（三塊

12V

串

聯的

10Ah

電(dian)池）所用的(de)三段式充(chong)電(dian)器(qi)為例簡單介(jie)紹一下：

 

 

 

 

 

 

 

 

首先(xian)討論(lun)涓流階段的低(di)恒壓(ya)值，

參考電壓為

42.5V

左右。

此值高將使電(dian)池(chi)失(shi)水，

容易

使電池(chi)發熱變形；此值(zhi)低(di)不(bu)利(li)于電池(chi)充(chong)足電。此值(zhi)在(zai)南方要低(di)于

41.5V

；膠體電池要低于

41.5V

，如在(zai)南方(fang)還要低一點兒。這個參(can)數是相(xiang)對(dui)嚴格的，不(bu)可以大于參(can)考值。

 

 

 

 

 

 

 

其次討論(lun)第(di)二階段的高恒壓值，參(can)考電壓為

44.5V

左(zuo)右(you)。此值高有利于(yu)快速充足電，

但是容易使電(dian)池失水，

充電后期(qi)電流(liu)下不來，

結果使電(dian)池發熱變形；

此值低不利于電池快速

充足電，有利于(yu)向涓(juan)流階段轉換。這個值雖然(ran)沒有第(di)一個值那樣嚴格(ge)，但是也不要過高。

 

 

 

 

 

 

 

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，

不容易發熱

本文介紹的(de)是有關鋰電(dian)池(chi)組保(bao)(bao)護板均衡充(chong)電(dian)基本工(gong)作原理，在采用(yong)單節(jie)鋰電(dian)池(chi)保(bao)(bao)護芯片設計的(de)且具備均衡充(chong)電(dian)能力的(de)鋰電(dian)池(chi)組保(bao)(bao)護板，示意(yi)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池數目確定，串聯使用(yong)，分別(bie)對(dui)所對(dui)應單(dan)節(jie)鋰電池的(de)充(chong)放電、過流、短路狀態進行保(bao)護(hu)。該系統在充(chong)電保(bao)護(hu)的(de)同時(shi)，通(tong)過保(bao)護(hu)芯片控制分流放電支路開(kai)關器件的(de)通(tong)斷實現均(jun)衡(heng)(heng)充(chong)電，該方(fang)案有(you)別(bie)于傳統的(de)在充(chong)電器端實現均(jun)衡(heng)(heng)充(chong)電的(de)做(zuo)法，降低了(le)鋰電池組充(chong)電器設計(ji)應用(yong)的(de)成(cheng)本(ben)。

圖1 具(ju)備均(jun)衡充電(dian)能力的鋰電(dian)池組保護板示意圖

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(zheng)負(fu)極(ji)兩(liang)端(duan)的分(fen)流(liu)放(fang)電(dian)支路放(fang)電(dian)，同(tong)時將串接在充(chong)電(dian)回(hui)路中的對(dui)應單體鋰(li)電(dian)池斷離(li)出充(chong)電(dian)回(hui)路。

鋰電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)組串聯(lian)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時，忽略單(dan)(dan)節(jie)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)容(rong)量(liang)差別(bie)的(de)影響(xiang)，一(yi)般(ban)內(nei)阻(zu)(zu)(zu)較小的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)先(xian)充(chong)(chong)滿(man)。此時，相(xiang)應的(de)過(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)保護(hu)信號(hao)控制分(fen)(fen)流(liu)放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)支(zhi)路的(de)開(kai)關器件閉合，在(zai)原電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)兩端并聯(lian)上一(yi)個分(fen)(fen)流(liu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)。根據電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)的(de)PNGV等(deng)效電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路模型(xing)，此時分(fen)(fen)流(liu)支(zhi)路電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)相(xiang)當于先(xian)充(chong)(chong)滿(man)的(de)單(dan)(dan)節(jie)鋰電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)的(de)負載，該(gai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)通(tong)過(guo)其放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，使(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)端電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)維(wei)持在(zai)充(chong)(chong)滿(man)狀態附近一(yi)個極(ji)小的(de)范圍內(nei)。假設第1節(jie)鋰電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)先(xian)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)完成，進入過(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)保護(hu)狀態，則主電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路及分(fen)(fen)流(liu)放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)支(zhi)路中電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)流(liu)向如圖3所(suo)示(shi)。當所(suo)有(you)單(dan)(dan)節(jie)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)均(jun)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)進入過(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)保護(hu)狀態時，全部單(dan)(dan)節(jie)鋰電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)大小在(zai)誤差范圍內(nei)完全相(xiang)等(deng)，各節(jie)保護(hu)芯(xin)片(pian)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)保護(hu)控制信號(hao)均(jun)變低(di)，無(wu)法為主電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路中的(de)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)控制開(kai)關器件提供柵極(ji)偏壓(ya)，使(shi)其關斷(duan)，主回路斷(duan)開(kai)，即實現均(jun)衡充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)過(guo)程完成。

圖3 分流均衡過程

當電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)組(zu)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時，外(wai)接負載分別(bie)接電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)組(zu)正負極BAT+和(he)(he)BAT-兩端(duan)，放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)流(liu)(liu)經電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)組(zu)負極BAT-、充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)開(kai)關(guan)(guan)器件(jian)(jian)、放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)開(kai)關(guan)(guan)器件(jian)(jian)、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)組(zu)中(zhong)單節(jie)鋰電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)N～1和(he)(he)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)組(zu)正極BAT+,電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)流(liu)(liu)向如圖(tu)4所示。系統中(zhong)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)部分單節(jie)鋰電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)保(bao)(bao)護(hu)芯片的(de)(de)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)欠電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓保(bao)(bao)護(hu)、過(guo)流(liu)(liu)和(he)(he)短路(lu)保(bao)(bao)護(hu)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)信號經光耦隔離后串(chuan)聯輸出，為主(zhu)(zhu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)中(zhong)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)開(kai)關(guan)(guan)器件(jian)(jian)的(de)(de)導通提供柵(zha)極電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓;一旦(dan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)組(zu)在放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)過(guo)程中(zhong)遇到(dao)單節(jie)鋰電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)欠電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓或者過(guo)流(liu)(liu)和(he)(he)短路(lu)等(deng)特殊情況，對應的(de)(de)單節(jie)鋰電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)保(bao)(bao)護(hu)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)信號變低，無法為主(zhu)(zhu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)中(zhong)的(de)(de)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)開(kai)關(guan)(guan)器件(jian)(jian)提供柵(zha)極偏(pian)壓，使其(qi)關(guan)(guan)斷，主(zhu)(zhu)回路(lu)斷開(kai)，即結束(shu)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)使用(yong)過(guo)程。

圖4 放電過程

一般鋰電(dian)(dian)池采用恒(heng)流(liu)-恒(heng)壓(TAPER)型(xing)(xing)充(chong)(chong)(chong)電(dian)(dian)控制，恒(heng)壓充(chong)(chong)(chong)電(dian)(dian)時(shi)，充(chong)(chong)(chong)電(dian)(dian)電(dian)(dian)流(liu)近(jin)似指數規律減小。系統中充(chong)(chong)(chong)放(fang)電(dian)(dian)主回路(lu)的開關器(qi)件可根據外(wai)部電(dian)(dian)路(lu)要求滿足的最(zui)大工(gong)作電(dian)(dian)流(liu)和(he)工(gong)作電(dian)(dian)壓選型(xing)(xing)。

控(kong)制電(dian)路(lu)的單節(jie)鋰(li)電(dian)池保護芯片可根據待保護的單節(jie)鋰(li)電(dian)池的電(dian)壓等(deng)級、保護延(yan)遲時間等(deng)選(xuan)型。

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充電(dian)電(dian)壓大小以及鋰電(dian)池(chi)的參(can)數和放電(dian)電(dian)流的大小計(ji)算得出。均衡(heng)(heng)電(dian)流應合理(li)選擇，如果(guo)太小，均衡(heng)(heng)效果(guo)不(bu)明(ming)顯；如果(guo)太大，系統的能量損(sun)耗(hao)大，均衡(heng)(heng)效率低，對鋰電(dian)池(chi)組熱(re)管理(li)要求高，一(yi)般電(dian)流大小可(ke)設計(ji)在(zai)50～100mA之(zhi)間。

分流(liu)放電(dian)(dian)(dian)(dian)支路電(dian)(dian)(dian)(dian)阻可采(cai)用功率電(dian)(dian)(dian)(dian)阻或電(dian)(dian)(dian)(dian)阻網(wang)絡實現(xian)。這里(li)采(cai)用電(dian)(dian)(dian)(dian)阻網(wang)絡實現(xian)分流(liu)放電(dian)(dian)(dian)(dian)支路電(dian)(dian)(dian)(dian)阻較為(wei)合理(li)，可以(yi)有效消除電(dian)(dian)(dian)(dian)阻偏差的影響，此外，還能起到降低熱(re)功耗的作用。