電動自行車專用控制器原理及其保護功能
電動自(zi)行車(che)專用控(kong)制器(qi)原理及(ji)其(qi)保護功(gong)能
一、控制器原理
簡略(lve)地講(jiang)控(kong)制(zhi)(zhi)器(qi)是(shi)由周邊(bian)器(qi)件(jian)和主芯片(pian)(或單片(pian)機)組成(cheng)。周邊(bian)器(qi)件(jian)是(shi)一(yi)(yi)些(xie)功(gong)(gong)能(neng)器(qi)件(jian),如執行、采(cai)樣等,它(ta)們是(shi)電(dian)阻、傳感器(qi)、橋式(shi)開(kai)關電(dian)路,以及(ji)輔助單片(pian)機或專用集成(cheng)電(dian)路完成(cheng)控(kong)制(zhi)(zhi)過程的(de)器(qi)件(jian); 單片(pian)機也稱微(wei)控(kong)制(zhi)(zhi)器(qi),是(shi)在一(yi)(yi)塊集成(cheng)片(pian)上(shang)把存貯器(qi)、有變換信(xin)號語(yu)言的(de)譯碼(ma)器(qi)、鋸齒(chi)波發生器(qi)和脈(mo)寬調制(zhi)(zhi)功(gong)(gong)能(neng)電(dian)路以及(ji)能(neng)使(shi)開(kai)關電(dian)路功(gong)(gong)率管(guan)導通(tong)或截止、通(tong)過方(fang)波控(kong)制(zhi)(zhi)功(gong)(gong)率管(guan)的(de)導通(tong)時間(jian)以控(kong)制(zhi)(zhi)電(dian)機轉速的(de)驅動電(dian)路、輸入輸出端口等集成(cheng)在一(yi)(yi)起,而構成(cheng)的(de)計算機片(pian)。這就是(shi)電(dian)動自行車的(de)智能(neng)控(kong)制(zhi)(zhi)器(qi),它(ta)是(shi)以“傻瓜”面目出現的(de)高技術產品。
控制(zhi)器(qi)的設計品(pin)質(zhi)、特性、所采用(yong)的微處理器(qi)的功(gong)能、功(gong)率開關器(qi)件(jian)電路及周邊器(qi)件(jian)布局等,直(zhi)接(jie)關系到(dao)整車的性能和運(yun)行狀(zhuang)態,也(ye)影響控制(zhi)器(qi)本身性能和效率。不同(tong)(tong)品(pin)質(zhi)的控制(zhi)器(qi),用(yong)在同(tong)(tong)一輛車上(shang),配(pei)用(yong)同(tong)(tong)一組相同(tong)(tong)充(chong)放(fang)電狀(zhuang)態的電池,有時(shi)也(ye)會在續駛能力上(shang)顯(xian)示出較大差別(bie)。
二、控(kong)制器的型式
目前,電(dian)動自行車所采用(yong)的控(kong)制器電(dian)路原理基本相同或接近。
有(you)刷(shua)和(he)無刷(shua)直流(liu)電(dian)(dian)機大都采用脈寬調制(zhi)的(de)(de)PWM控(kong)(kong)制(zhi)方法調速,只是選(xuan)用驅動電(dian)(dian)路(lu)、集成電(dian)(dian)路(lu)、開關電(dian)(dian)路(lu)功(gong)率晶體管和(he)某些相關功(gong)能上(shang)的(de)(de)差(cha)別。元器件和(he)電(dian)(dian)路(lu)上(shang)的(de)(de)差(cha)異,構成了控(kong)(kong)制(zhi)器性(xing)能上(shang)的(de)(de)不大相同。控(kong)(kong)制(zhi)器從結構上(shang)分(fen)兩(liang)種,分(fen)別為分(fen)離式(shi)和(he)整體式(shi)。
1、分離式
所謂分(fen)離,是指控(kong)制器主(zhu)體和顯示部分(fen)分(fen)離。后者安裝在車(che)把上,控(kong)制器主(zhu)體則隱(yin)藏在車(che)體包廂或電動箱內,不露在外面。這種(zhong)方式(shi)使控(kong)制器與電源、電機間連線距離縮短,車(che)體外觀顯得簡潔。
2、一體式
控制部分與顯示部分合為一體,裝在一個精致的專用塑料盒子里。盒子安裝在車把的正中,盒子的面板上開有數量不等的小孔,孔徑4-5mm,外敷透明防水膜。孔內相應位置設有發光二極管以指示車速、電源和電池剩余電量。
三、控制器的(de)保護功能
保護(hu)(hu)功能(neng)(neng)是對控制器中換相功率管(guan)、電源(yuan)免過放電,以及電動機在運(yun)行中因某種故障或誤(wu)操作而導致的可能(neng)(neng)引起的損傷(shang)等故障出現時,電路根據反饋信號采(cai)取的保護(hu)(hu)措施。電動自(zi)行車控制器基本的保護(hu)(hu)功能(neng)(neng)和擴展功能(neng)(neng)如(ru)下(xia):
1、制動斷電
電(dian)動(dong)自行車車把(ba)上兩(liang)個鉗形制動(dong)手(shou)把(ba)均安裝有接點開關(guan)。當制動(dong)時(shi),開關(guan)被推押閉合或被斷(duan)開,而改變了(le)(le)原來(lai)的(de)開關(guan)狀態。這個變化(hua)形成(cheng)信號傳送到控制電(dian)路中,電(dian)路根(gen)據(ju)預(yu)設程(cheng)序發出指(zhi)令,立即切斷(duan)基極驅動(dong)電(dian)流,使功率截止(zhi),停止(zhi)供(gong)電(dian)。因(yin)而,既保(bao)護了(le)(le)功率管本身,又(you)保(bao)護了(le)(le)電(dian)動(dong)機,也防止(zhi)了(le)(le)電(dian)源的(de)浪費。
2、欠壓保護
這(zhe)里指的是電(dian)(dian)(dian)(dian)(dian)源的電(dian)(dian)(dian)(dian)(dian)壓(ya)。當放電(dian)(dian)(dian)(dian)(dian)最后階段,在負載狀態(tai)下,電(dian)(dian)(dian)(dian)(dian)源電(dian)(dian)(dian)(dian)(dian)壓(ya)已經接近(jin)“放電(dian)(dian)(dian)(dian)(dian)終止電(dian)(dian)(dian)(dian)(dian)壓(ya)”,控制器(qi)面(mian)板(或儀(yi)表顯示盤)即顯示電(dian)(dian)(dian)(dian)(dian)量不(bu)足,引起(qi)騎行者的注意,計劃自己(ji)的行程(cheng)。當電(dian)(dian)(dian)(dian)(dian)源電(dian)(dian)(dian)(dian)(dian)壓(ya)已經達到放終時,電(dian)(dian)(dian)(dian)(dian)壓(ya)取樣電(dian)(dian)(dian)(dian)(dian)阻(zu)將分流信息(xi)饋入(ru)比較器(qi),保護(hu)電(dian)(dian)(dian)(dian)(dian)路即按預先(xian)設定(ding)的程(cheng)序發出指令,切斷電(dian)(dian)(dian)(dian)(dian)流以保護(hu)電(dian)(dian)(dian)(dian)(dian)子器(qi)件和電(dian)(dian)(dian)(dian)(dian)源。
3、過流保護
電(dian)流(liu)超(chao)限對電(dian)機(ji)和電(dian)路(lu)一(yi)系列元器(qi)件都可能(neng)(neng)造成損傷(shang),甚至燒毀,這是絕(jue)對應當避(bi)免的(de)。控制電(dian)路(lu)中,必須具備這種過電(dian)流(liu)的(de)保護功能(neng)(neng),在過流(liu)時經過一(yi)定的(de)延時即切斷(duan)電(dian)流(liu)。
4、過載保護
過(guo)(guo)(guo)載(zai)(zai)保(bao)護(hu)和過(guo)(guo)(guo)電(dian)(dian)流保(bao)護(hu)是(shi)相同的(de)(de)(de),載(zai)(zai)重超(chao)(chao)限(xian)必然引(yin)起(qi)電(dian)(dian)流超(chao)(chao)限(xian)。電(dian)(dian)動自(zi)行車說(shuo)明(ming)書上都特別注明(ming)載(zai)(zai)重能(neng)力,但(dan)(dan)有(you)的(de)(de)(de)騎(qi)行者或(huo)未(wei)注意這一(yi)點,或(huo)抱(bao)著試一(yi)下的(de)(de)(de)心理故意超(chao)(chao)載(zai)(zai)。如果沒(mei)有(you)這種(zhong)保(bao)護(hu)功(gong)能(neng),不一(yi)定(ding)在哪個(ge)(ge)環節上引(yin)起(qi)損傷,但(dan)(dan)首(shou)當(dang)其沖的(de)(de)(de)就是(shi)開關功(gong)率(lv)管,只要無刷(shua)控制器功(gong)率(lv)管燒毀1只,變(bian)成兩(liang)相供電(dian)(dian)后(hou)(hou)電(dian)(dian)動機運(yun)轉即變(bian)得(de)無力,騎(qi)行者立即可以感覺到脈動異常(chang);若繼續騎(qi)行,接(jie)著就燒毀第2個(ge)(ge)、第3個(ge)(ge)功(gong)率(lv)管。有(you)兩(liang)相功(gong)率(lv)管不工作,電(dian)(dian)動機即停止運(yun)行,有(you)刷(shua)電(dian)(dian)機則(ze)失去控制功(gong)能(neng)。因(yin)此,由過(guo)(guo)(guo)載(zai)(zai)引(yin)起(qi)的(de)(de)(de)過(guo)(guo)(guo)電(dian)(dian)流是(shi)很(hen)危險的(de)(de)(de)。但(dan)(dan)只要有(you)過(guo)(guo)(guo)電(dian)(dian)流保(bao)護(hu),載(zai)(zai)重超(chao)(chao)限(xian)后(hou)(hou)電(dian)(dian)路自(zi)動切(qie)斷(duan)電(dian)(dian)源(yuan),因(yin)超(chao)(chao)載(zai)(zai)而(er)引(yin)起(qi)的(de)(de)(de)一(yi)系列后(hou)(hou)果都可以避免。
5、欠速保護
仍(reng)然屬(shu)于過流保護范疇,是為(wei)不具備零速起步功能的無刷控制系(xi)統(tong)而設置。
6、限速保護
是(shi)助(zhu)(zhu)力型電(dian)(dian)動自行(xing)車(che)(che)(che)獨有的(de)設計控制(zhi)(zhi)程序(xu)。車(che)(che)(che)速(su)(su)超過(guo)某一預(yu)定(ding)值時(shi),電(dian)(dian)路停止供電(dian)(dian)不予(yu)助(zhu)(zhu)力。對電(dian)(dian)動型電(dian)(dian)動自行(xing)車(che)(che)(che)而言,統一規(gui)定(ding)車(che)(che)(che)速(su)(su)為(wei)20km/h,車(che)(che)(che)用電(dian)(dian)動機(ji)在設計時(shi),額定(ding)轉速(su)(su)就(jiu)已經(jing)設定(ding)好了,控制(zhi)(zhi)電(dian)(dian)路也已經(jing)設好,動自行(xing)車(che)(che)(che)只能在不超過(guo)這個速(su)(su)度狀(zhuang)態下運行(xing)。
控制(zhi)器的位置不會影(ying)響到性能,主要視(shi)設(she)(she)計者的意(yi)圖,但有幾項原(yuan)則:①、在(zai)運行操作允許時(shi);②、在(zai)整體布(bu)置允許時(shi);③、在(zai)線路布(bu)設(she)(she)要求時(shi);④、在(zai)配套設(she)(she)施要求時(shi)。