鑒于市場上鎳鎘電池和鋰電池共存的局面，本文設計的充電器可以對(dui)這兩種電(dian)(dian)(dian)池(chi)(chi)進行充(chong)電(dian)(dian)(dian)，對(dui)鎳鎘電(dian)(dian)(dian)池(chi)(chi)組(zu)(zu)采用脈沖充(chong)電(dian)(dian)(dian)方式，對(dui)鋰電(dian)(dian)(dian)池(chi)(chi)組(zu)(zu)采用恒流充(chong)電(dian)(dian)(dian)方式，這是依據電(dian)(dian)(dian)池(chi)(chi)的(de)(de)不同機(ji)理(li)而設計的(de)(de)，真正做(zuo)到(dao)了(le)一機(ji)兩用，此為該充(chong)電(dian)(dian)(dian)器(qi)的(de)(de)創新點，也是設計的(de)(de)難點。充(chong)電(dian)(dian)(dian)器(qi)的(de)(de)寬(kuan)屏LCD可以同時顯示4組(zu)(zu)充(chong)電(dian)(dian)(dian)器(qi)的(de)(de)充(chong)電(dian)(dian)(dian)狀態(tai)，也可單獨顯示一組(zu)(zu)充(chong)電(dian)(dian)(dian)器(qi)上電(dian)(dian)(dian)池(chi)(chi)的(de)(de)各項參(can)數，做(zuo)到(dao)了(le)對(dui)電(dian)(dian)(dian)池(chi)(chi)充(chong)電(dian)(dian)(dian)過(guo)程的(de)(de)實時監測。

　　系統整體設計

　　系統設計目標(biao)是：

　　1．可(ke)同(tong)時對4組8.4V的(de)鋰離(li)子電池(chi)或9.2V的(de)鎳鎘電池(chi)進行(xing)充放電。

　　2．可(ke)與電(dian)(dian)池(chi)組中的芯片(pian)通信，判斷(duan)電(dian)(dian)池(chi)的化(hua)學(xue)性質(zhi)。

　　3．對(dui)于不同化學性質的電池，將采用相(xiang)應(ying)的充電方(fang)式。

　　4．可(ke)與電池(chi)組中的芯(xin)片(pian)通信(xin)，得(de)到該電池(chi)組的電壓、充(chong)電電流、容量等參(can)數。

　　5．充電器帶有LCD，可顯(xian)示電池的各項數據。

　　該充電器的功(gong)能框圖如(ru)圖1所示。

　　
       系統硬件設計

　　總控(kong)單元的(de)設計(ji)與實現

　　總控單元是(shi)由微(wei)控制(zhi)器PIC16F873和鍵(jian)盤控制(zhi)芯片(pian)ZLG7289A構成的。主要(yao)任務(wu)是(shi)負責與各

個(ge)充電單元通(tong)(tong)信，并(bing)處理用戶輸入與LCD顯(xian)示信息(xi)。鍵(jian)盤(pan)控(kong)制芯片在這里負責6個(ge)按鍵(jian)和12個(ge)LED的(de)控(kong)制。ZLG7289A與微控(kong)制器之(zhi)間通(tong)(tong)過SPI總線(xian)進(jin)行雙向(xiang)通(tong)(tong)信。主控(kong)單元每(mei)秒查詢一次各(ge)個(ge)充電單元，獲取(qu)當前(qian)充電單元的(de)信息(xi)，如有(you)無電池、電池性質、電池電壓等(deng)。之(zhi)后由LCD模塊向(xiang)用戶顯(xian)示。

　　充電單(dan)元的設計(ji)與實現

　　LTC4002鋰(li)離子電(dian)池充電(dian)控制芯片

　　LTC4002是一款高效獨(du)立(li)開關(guan)模(mo)式(shi)鋰離子電(dian)(dian)池充(chong)電(dian)(dian)控(kong)制(zhi)(zhi)器(qi)(qi)。該(gai)控(kong)制(zhi)(zhi)器(qi)(qi)有(you)4.2V和8.4V兩個版本。LTC4002-8.4具有(you)500kHz開關(guan)頻率(lv)，是高效電(dian)(dian)流模(mo)式(shi)的PWM控(kong)制(zhi)(zhi)器(qi)(qi)。通(tong)過驅動一個外(wai)(wai)部(bu)P溝道MOSFET，它可以提供(gong)4A的充(chong)電(dian)(dian)電(dian)(dian)流，而(er)效率(lv)可高達90％。輸出電(dian)(dian)壓(ya)設置(zhi)為8.4V，最終浮動電(dian)(dian)壓(ya)并具1％的精度，而(er)充(chong)電(dian)(dian)準(zhun)確(que)度為5％。此外(wai)(wai)，該(gai)器(qi)(qi)件可在(zai)9V～22V范圍內的多種墻(qiang)上適配器(qi)(qi)上運行(xing)。與(yu)(yu)遲滯(zhi)拓撲結構充(chong)電(dian)(dian)器(qi)(qi)相比，LTC4002-8.4的快速運行(xing)頻率(lv)與(yu)(yu)電(dian)(dian)流模(mo)式(shi)架構使之能夠使用小型(xing)電(dian)(dian)感器(qi)(qi)和電(dian)(dian)容(rong)器(qi)(qi)。

　　鋰(li)離子(zi)／鎳鎘(ge)電(dian)(dian)池兩用充電(dian)(dian)單元的總體設(she)計

　　從前面對(dui)(dui)LTC4002的(de)分析可(ke)知(zhi)，該芯片是(shi)(shi)針(zhen)對(dui)(dui)鋰(li)(li)離(li)(li)子電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)的(de)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)控(kong)制器(qi)，要實現對(dui)(dui)鎳(nie)鎘(ge)(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)需(xu)要解決以(yi)(yi)下問題(ti)：首先(xian)，LTC4002對(dui)(dui)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)進行(xing)監測，保證電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)不超過8.4V。但對(dui)(dui)于鎳(nie)鎘(ge)(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)組，充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)截(jie)止電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)可(ke)以(yi)(yi)達到9.2V。其(qi)次(ci)，鎳(nie)鎘(ge)(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)即將結束(shu)時(shi)，需(xu)要對(dui)(dui)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)進行(xing)以(yi)(yi)正常電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)30％和(he)10％的(de)涓流(liu)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。所以(yi)(yi)，第二個需(xu)要解決的(de)問題(ti)是(shi)(shi)如(ru)何控(kong)制恒流(liu)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)大(da)小。此外(wai)，對(dui)(dui)鎳(nie)鎘(ge)(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)應(ying)使用(yong)脈沖充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)方式。即以(yi)(yi)1s為周期(qi)，95％的(de)時(shi)間用(yong)來充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，1％的(de)時(shi)間用(yong)來放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，其(qi)余時(shi)間不充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)也不放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。最(zui)后，如(ru)何判(pan)斷某一個電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)是(shi)(shi)鋰(li)(li)離(li)(li)子電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)還是(shi)(shi)鎳(nie)鎘(ge)(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)，因為若把鋰(li)(li)離(li)(li)子電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)誤(wu)判(pan)為鎳(nie)鎘(ge)(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)，會(hui)使充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)高于8.4V，這對(dui)(dui)鋰(li)(li)離(li)(li)子電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)是(shi)(shi)十分危險(xian)的(de)，而(er)將鎳(nie)鎘(ge)(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)誤(wu)判(pan)為鋰(li)(li)離(li)(li)子電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)，則可(ke)能造(zao)成電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)(chi)充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)不足。因此，必須保證極低的(de)誤(wu)判(pan)率。

　　本部分根據LTC4002的(de)工(gong)作原(yuan)理(li)，設計了(le)既可(ke)(ke)以對(dui)鋰離子(zi)電(dian)(dian)(dian)(dian)池(chi)進行(xing)恒流-恒壓充(chong)電(dian)(dian)(dian)(dian)，又可(ke)(ke)以對(dui)鎳鎘電(dian)(dian)(dian)(dian)池(chi)進行(xing)脈(mo)沖式充(chong)電(dian)(dian)(dian)(dian)的(de)電(dian)(dian)(dian)(dian)路(lu)。充(chong)電(dian)(dian)(dian)(dian)單元(yuan)的(de)總體功能框圖如(ru)圖2所示。其中，信號調理(li)電(dian)(dian)(dian)(dian)路(lu)使充(chong)電(dian)(dian)(dian)(dian)器(qi)既可(ke)(ke)以對(dui)8.4V的(de)鋰電(dian)(dian)(dian)(dian)池(chi)充(chong)電(dian)(dian)(dian)(dian)，又可(ke)(ke)以對(dui)9.2V的(de)鎳鎘電(dian)(dian)(dian)(dian)池(chi)充(chong)電(dian)(dian)(dian)(dian)，同時也起到控制充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流大小的(de)作用。

　　利(li)用(yong)微控制(zhi)器控制(zhi)LTC4002的(de)工(gong)作(zuo)狀態(tai)，配合放電電路(lu)使充電器可以(yi)對鎳鎘電池進(jin)行脈(mo)沖方式充電。

　　微(wei)控制(zhi)器(qi)通過一定(ding)的通信協議(HDQ16)與智能電(dian)池通信，確定(ding)其容量(liang)、化學性質等(deng)關鍵參(can)數。

　　信號調理電路(lu)的設計

　　為了使LTC4002可對高于8.4V的(de)(de)(de)電(dian)(dian)(dian)池(chi)進(jin)行(xing)恒流充電(dian)(dian)(dian)，并(bing)可調(diao)節充電(dian)(dian)(dian)電(dian)(dian)(dian)流，在LTC4002的(de)(de)(de)BAT和SENSE端(duan)與采樣電(dian)(dian)(dian)阻(zu)之(zhi)間加(jia)入一(yi)級信(xin)號(hao)(hao)(hao)調(diao)理(li)電(dian)(dian)(dian)路。該電(dian)(dian)(dian)路的(de)(de)(de)主要功能(neng)是對采樣電(dian)(dian)(dian)阻(zu)兩(liang)端(duan)的(de)(de)(de)信(xin)號(hao)(hao)(hao)進(jin)行(xing)運算，針(zhen)對不同(tong)化學(xue)性質的(de)(de)(de)電(dian)(dian)(dian)池(chi)，將相應的(de)(de)(de)信(xin)號(hao)(hao)(hao)送給LTC4002。該信(xin)號(hao)(hao)(hao)調(diao)理(li)電(dian)(dian)(dian)路如圖(tu)3所示。

這里定(ding)義采(cai)(cai)樣(yang)電(dian)(dian)(dian)(dian)(dian)(dian)阻兩(liang)(liang)端(duan)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)值(zhi)是VBAT和(he)Vsense，那(nei)(nei)么(me)充電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)在采(cai)(cai)樣(yang)電(dian)(dian)(dian)(dian)(dian)(dian)阻上的(de)(de)(de)壓(ya)降VRS為(wei)：VRS=Vsense-VBAT，該信(xin)號為(wei)減(jian)法器的(de)(de)(de)輸(shu)出。設乘法器的(de)(de)(de)乘系數為(wei)K，那(nei)(nei)么(me)乘法器的(de)(de)(de)輸(shu)出為(wei)KVRS。對于鋰子電(dian)(dian)(dian)(dian)(dian)(dian)池，二(er)選(xuan)(xuan)(xuan)一(yi)開關(guan)將(jiang)選(xuan)(xuan)(xuan)通(tong)電(dian)(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)VBAT；對于鎳鎘(ge)電(dian)(dian)(dian)(dian)(dian)(dian)池，二(er)選(xuan)(xuan)(xuan)一(yi)開關(guan)將(jiang)選(xuan)(xuan)(xuan)通(tong)7V恒(heng)定(ding)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)。這里設二(er)選(xuan)(xuan)(xuan)一(yi)模擬開關(guan)的(de)(de)(de)輸(shu)出為(wei)V1，那(nei)(nei)么(me)加法器的(de)(de)(de)輸(shu)出Vs應(ying)為(wei)：Vs=KVRS+V1，這樣(yang)一(yi)來，送到LTC4002的(de)(de)(de)BAT和(he)SENSE兩(liang)(liang)端(duan)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)之(zhi)差應(ying)為(wei)KVRS。只(zhi)要(yao)正確控制K值(zhi)，就可(ke)(ke)以(yi)使(shi)充電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)為(wei)正常充電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)的(de)(de)(de)1／K。因此，可(ke)(ke)以(yi)通(tong)過二(er)選(xuan)(xuan)(xuan)一(yi)開關(guan)控制電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)為(wei)恒(heng)流(liu)(liu)充電(dian)(dian)(dian)(dian)(dian)(dian)時的(de)(de)(de)10％或30％。

　　對于LTC4002的(de)BAT端(duan)輸(shu)入(ru)值，當開關選(xuan)通(tong)鋰離子電(dian)池時，BAT的(de)輸(shu)入(ru)即是電(dian)池電(dian)壓。此時，LTC4002可(ke)以控制整(zheng)個(ge)鋰離子的(de)充電(dian)過程。不需任何外界的(de)干(gan)預。

　　當(dang)開關(guan)選通(tong)了7V恒(heng)定(ding)電(dian)(dian)(dian)(dian)(dian)壓后，BAT端的(de)(de)輸入恒(heng)定(ding)為(wei)(wei)(wei)7V，此時，LTC4002無法知道電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)真實(shi)電(dian)(dian)(dian)(dian)(dian)壓，只(zhi)認為(wei)(wei)(wei)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)壓為(wei)(wei)(wei)7V。所以(yi)，盡管電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)壓高于(yu)8.4V，仍會(hui)以(yi)恒(heng)定(ding)電(dian)(dian)(dian)(dian)(dian)流對電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)進(jin)行(xing)充(chong)電(dian)(dian)(dian)(dian)(dian)。在這(zhe)種情況下，需要微控制器的(de)(de)干預，否則，會(hui)造(zao)成(cheng)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)過(guo)充(chong)。由于(yu)微控制器內(nei)部帶有ADC，可以(yi)監測電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)壓的(de)(de)變化。當(dang)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)壓達(da)到指(zhi)定(ding)值(zhi)時，減小充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流，直至(zhi)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)滿。這(zhe)樣就可以(yi)對9.2V的(de)(de)鎳鎘電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)進(jin)行(xing)充(chong)電(dian)(dian)(dian)(dian)(dian)了。

　　脈沖充放電(dian)電(dian)路的設(she)計

　　由于(yu)LTC4002是恒(heng)流(liu)充(chong)電(dian)(dian)(dian)控(kong)制芯片，因此，必須(xu)使用微控(kong)制器控(kong)制其充(chong)電(dian)(dian)(dian)使能引(yin)腳(jiao)COMP。當需要LTC4002輸出(chu)充(chong)電(dian)(dian)(dian)脈沖時(shi)，使控(kong)制COMP引(yin)腳(jiao)的(de)端口(kou)變為高阻(zu)態(tai)，使COMP引(yin)腳(jiao)自行升至(zhi)360mV以(yi)上時(shi)，便(bian)有充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)輸出(chu)。放電(dian)(dian)(dian)時(shi)，必須(xu)將COMP引(yin)腳(jiao)拉(la)低，使LTC4002關斷充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)。之后(hou)，再(zai)打(da)開(kai)放電(dian)(dian)(dian)電(dian)(dian)(dian)路。微控(kong)制器選用PIC16F873，它是一款基(ji)于(yu)Fla

sh的8位微控制器。內部有定時器、看門(men)狗電路、10位ADC等模塊。

　　微控(kong)制器以1s為(wei)周期(qi)對鎳鎘電池進行脈沖充放電。

　　系統軟件設計

　　系統軟件總(zong)體設計

　　充(chong)電(dian)(dian)(dian)(dian)(dian)單(dan)元中的(de)微控制器主(zhu)要負責充(chong)電(dian)(dian)(dian)(dian)(dian)過程的(de)控制和與(yu)總控板的(de)通信，程序流程如(ru)圖(tu)4所示。充(chong)電(dian)(dian)(dian)(dian)(dian)單(dan)元首先判斷是否有(you)(you)電(dian)(dian)(dian)(dian)(dian)池，如(ru)果有(you)(you)電(dian)(dian)(dian)(dian)(dian)池放(fang)入，則判斷充(chong)放(fang)電(dian)(dian)(dian)(dian)(dian)狀(zhuang)態(tai)(tai)(tai)，默認是充(chong)電(dian)(dian)(dian)(dian)(dian)狀(zhuang)態(tai)(tai)(tai)，該狀(zhuang)態(tai)(tai)(tai)可(ke)由總控單(dan)元改變。若(ruo)充(chong)電(dian)(dian)(dian)(dian)(dian)單(dan)元處(chu)于充(chong)電(dian)(dian)(dian)(dian)(dian)狀(zhuang)態(tai)(tai)(tai)，則繼續(xu)判斷電(dian)(dian)(dian)(dian)(dian)池的(de)化學性質，針對不同的(de)電(dian)(dian)(dian)(dian)(dian)池采用不同的(de)充(chong)電(dian)(dian)(dian)(dian)(dian)方式(shi)。若(ruo)處(chu)于放(fang)電(dian)(dian)(dian)(dian)(dian)狀(zhuang)態(tai)(tai)(tai)，則對電(dian)(dian)(dian)(dian)(dian)池組進行(xing)放(fang)電(dian)(dian)(dian)(dian)(dian)，直到電(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)壓(ya)低(di)于閾值電(dian)(dian)(dian)(dian)(dian)壓(ya)后(hou)，轉為充(chong)電(dian)(dian)(dian)(dian)(dian)狀(zhuang)態(tai)(tai)(tai)。

　　除主(zhu)程(cheng)序外，總(zong)控單(dan)(dan)元(yuan)與充(chong)(chong)電(dian)單(dan)(dan)元(yuan)的(de)(de)(de)通信(xin)是在中(zhong)斷(duan)服務程(cheng)序中(zhong)實現的(de)(de)(de)。當充(chong)(chong)電(dian)單(dan)(dan)元(yuan)收到總(zong)控單(dan)(dan)元(yuan)的(de)(de)(de)指令(ling)(ling)后(hou)，進入中(zhong)斷(duan)。若(ruo)指令(ling)(ling)是查詢數據指令(ling)(ling)，則(ze)向總(zong)控單(dan)(dan)元(yuan)發送需要的(de)(de)(de)數據。若(ruo)是充(chong)(chong)電(dian)狀態設置指令(ling)(ling)，則(ze)依據指令(ling)(ling)設置充(chong)(chong)電(dian)單(dan)(dan)元(yuan)的(de)(de)(de)充(chong)(chong)電(dian)狀態。

　　通信協議的實現

　　通過與電池組中電能計量芯片通信的方法來判斷電池的性質。本系統可以與遵循HDQ16接口協議的智能電池組進行通信，除了電池組的化學性質外，還可以將電池組的容量、電壓、充電電流、編號等數據一并讀取，供充電器顯示之用。

　　充電單元可以通過HDQ總線對(dui)智(zhi)能電池進(jin)行讀操(cao)作(zuo)。HDQ16接口協議(yi)是(shi)基于指(zhi)(zhi)(zhi)(zhi)令的(de)(de)協議(yi)。一個處理(li)器(qi)(qi)發(fa)送8位(wei)(wei)指(zhi)(zhi)(zhi)(zhi)令碼(ma)給智(zhi)能電池，這個8位(wei)(wei)的(de)(de)指(zhi)(zhi)(zhi)(zhi)令碼(ma)由(you)兩部分組成，7位(wei)(wei)HDQ16指(zhi)(zhi)(zhi)(zhi)令碼(ma)(位(wei)(wei)0～6)和1位(wei)(wei)讀／寫指(zhi)(zhi)(zhi)(zhi)令。讀／寫指(zhi)(zhi)(zhi)(zhi)令指(zhi)(zhi)(zhi)(zhi)示(shi)智(zhi)能 電池存(cun)儲接下來的(de)(de)16位(wei)(wei)數(shu)據到一個指(zhi)(zhi)(zhi)(zhi)定的(de)(de)寄存(cun)器(qi)(qi)，或者從指(zhi)(zhi)(zhi)(zhi)定的(de)(de)寄存(cun)器(qi)(qi)輸出16位(wei)(wei)數(shu)據。在HDQ16里(li)，數(shu)據字節(指(zhi)(zhi)(zhi)(zhi)令)或者字(數(shu)據)的(de)(de)最不重要的(de)(de)位(wei)(wei)會優先(xian)傳(chuan)輸。

　　一個塊的傳輸包括三個不同的部(bu)分。第(di)一部(bu)分經由(you)主(zhu)機(ji)或(huo)者智(zhi)能電池把(ba)HDQ16引腳置(zhi)邏(luo)輯低(di)狀態一個tSTRH：B時間后開始發(fa)送。接下來的部(bu)分是真正的數(shu)(shu)據(ju)傳輸，數(shu)(shu)據(ju)位(wei)在tDSU:B時間間隔里是有(you)效的，負邊界用來開始通(tong)信。數(shu)(shu)據(ju)位(wei)被(bei)保持一個tDH:DV時間間隔，以(yi)便(bian)允許主(zhu)機(ji)或(huo)智(zhi)能電池采樣數(shu)(shu)據(ju)位(wei)。

　　在負邊界(jie)開始通信后，最(zui)后一部分(fen)通過返回給HDQ16引腳一個邏(luo)輯高狀態，至(zhi)少保持tSSU:B時(shi)間(jian)間(jian)隔來停止(zhi)傳輸。最(zui)后一個邏(luo)輯高狀態必須(xu)保持一個tCYCH:B時(shi)間(jian)間(jian)隔，以便有時(shi)間(jian)讓塊傳輸完全停止(zhi)。

　　如果發(fa)生通信錯誤(e.g.，tCYCB>250μs)，主(zhu)機就(jiu)發(fa)送給智能電(dian)(dian)池一(yi)個(ge)BREAK信號，讓其(qi)控制串行接口。當HDQ16引腳在一(yi)個(ge)時(shi)間間隔，或者更長時(shi)間里為邏(luo)輯低狀態時(shi)，智能電(dian)(dian)池就(jiu)會(hui)偵測BREAK。然后，HDQ16引腳回到其(qi)正常(chang)預(yu)設高(gao)邏(luo)輯狀態一(yi)個(ge)tBR時(shi)間間隔。然后，智能電(dian)(dian)池就(jiu)準備從主(zhu)機那(nei)里接收(shou)指(zhi)令。

　　HDQ16引(yin)腳是開(kai)漏的，需要一個(ge)外部的上拉電(dian)阻。

　　圖5是用邏輯分析儀顯示(shi)的一(yi)次HDQ總線(xian)上的通信波形。

　　本文提(ti)出(chu)的(de)(de)(de)充(chong)電(dian)(dian)系統(tong)從技(ji)術(shu)上(shang)很好地解決了上(shang)述問題，通(tong)(tong)過LCD顯示屏可(ke)以(yi)清(qing)晰便捷(jie)地讀出(chu)電(dian)(dian)源(yuan)的(de)(de)(de)剩余容(rong)量、已有(you)充(chong)放電(dian)(dian)次數、充(chong)電(dian)(dian)及放電(dian)(dian)電(dian)(dian)流(liu)、電(dian)(dian)池(chi)電(dian)(dian)壓、容(rong)量統(tong)計和(he)電(dian)(dian)池(chi)特性等(deng)重要(yao)內容(rong)，并且通(tong)(tong)過設定，可(ke)以(yi)判斷(duan)電(dian)(dian)源(yuan)是否達到(dao)報(bao)廢標準，及時提(ti)醒(xing)操作(zuo)者(zhe)更(geng)新電(dian)(dian)源(yuan)。為電(dian)(dian)源(yuan)維護保(bao)養(yang)工作(zuo)提(ti)供明確(que)的(de)(de)(de)參考數據(ju)，降低了對操作(zuo)人員(yuan)專業技(ji)術(shu)水平的(de)(de)(de)要(yao)求，保(bao)證(zheng)了列車(che)尾部電(dian)(dian)源(yuan)的(de)(de)(de)安全使用(yong)。