現代電動自行車是融合電力電子、機械、控制、材料以及化工等領域各種新技術的綜合產品。我國電動自行車發展的總體目標是生產出在性能和價格上都能媲美于燃油助動車的適合于城市交通的綠色輕便代步工具。實現這一目標的關鍵在于開發高性能、低成本、安全可靠的動力蓄電池。盡管目前電池儲能技術還沒有得到相應的發展。但新型蓄電池如氫鎳電池、鋰電池、鋅―空氣電池和燃料電池的問世和快速電池充電器技術(shu)的發明，為(wei)電動自行車(che)最終取代燃(ran)油助動車(che)提供了樂觀(guan)的保證(zheng)。

     電氣傳動系(xi)統

     1、電(dian)動自行車對(dui)電(dian)氣(qi)傳動系統(tong)的要求

     電(dian)(dian)(dian)(dian)氣(qi)傳動(dong)系(xi)統(tong)是電(dian)(dian)(dian)(dian)動(dong)自(zi)行車的(de)驅動(dong)和控(kong)制中心(xin)，其系(xi)統(tong)結(jie)構如圖1所示(shi)。對(dui)其要(yao)(yao)求(qiu)是：結(jie)構簡單，外(wai)形尺寸(cun)小，重(zhong)量(liang)輕，效率高(gao)，免維護(hu)或(huo)少維護(hu)。電(dian)(dian)(dian)(dian)動(dong)自(zi)行車的(de)電(dian)(dian)(dian)(dian)機(ji)應具有高(gao)功率密度(du)和圖2所示(shi)的(de)矩(ju)―轉速(su)特性：基速(su)以下大轉矩(ju)，適(shi)應車輛負荷爬坡、頻繁起制動(dong)等(deng)要(yao)(yao)求(qiu)；基速(su)以上小轉矩(ju)、恒(heng)功率，保證車輛在平坦路面上快速(su)騎行。同時，電(dian)(dian)(dian)(dian)機(ji)在整個轉矩(ju)―轉速(su)運行范圍內應保持高(gao)效率，以謀求(qiu)電(dian)(dian)(dian)(dian)池一次充電(dian)(dian)(dian)(dian)后的(de)續駛里程盡可能(neng)長。2、無刷(shua)直流電(dian)(dian)(dian)(dian)機(ji)的(de)控(kong)制規(gui)律

     無(wu)刷(shua)直流(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)具有(you)(you)很高的(de)(de)(de)能(neng)量密度，其(qi)體積(ji)僅(jin)為相(xiang)同(tong)功率普(pu)通直流(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)的(de)(de)(de)50％，且重量輕(qing)、效(xiao)率高。用于電(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)自(zi)行車的(de)(de)(de)永磁(ci)無(wu)刷(shua)直流(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)有(you)(you)兩類(lei)：內轉子和(he)(he)外轉子，其(qi)中外轉子電(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)更(geng)適合構(gou)成(cheng)電(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)輪(lun)毅(yi)，在(zai)(zai)電(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)自(zi)行車中有(you)(you)較多(duo)應用。電(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)自(zi)行車主要在(zai)(zai)市區騎行，車速(su)不高，并且起、停頻繁，因此(ci)電(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)普(pu)遍采用多(duo)極三相(xiang)結構(gou)。控(kong)制器(qi)(qi)為雙向(xiang)DC／AC變(bian)流(liu)(liu)(liu)器(qi)(qi)，車輛前(qian)進時，變(bian)流(liu)(liu)(liu)器(qi)(qi)控(kong)制電(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)工(gong)作(zuo)在(zai)(zai)電(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)工(gong)況；車輛制動(dong)(dong)時，變(bian)流(liu)(liu)(liu)器(qi)(qi)控(kong)制電(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)工(gong)作(zuo)在(zai)(zai)發電(dian)(dian)(dian)(dian)(dian)(dian)工(gong)況，實現再(zai)生制動(dong)(dong)，將機(ji)(ji)(ji)械能(neng)轉換(huan)成(cheng)電(dian)(dian)(dian)(dian)(dian)(dian)能(neng)反(fan)饋回蓄電(dian)(dian)(dian)(dian)(dian)(dian)池。圖3是(shi)由(you)變(bian)流(liu)(liu)(liu)器(qi)(qi)、轉子位置檢測器(qi)(qi)和(he)(he)永磁(ci)同(tong)步電(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)構(gou)成(cheng)的(de)(de)(de)永磁(ci)無(wu)刷(shua)直流(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)原(yuan)理圖。其(qi)中變(bian)流(liu)(liu)(liu)器(qi)(qi)為電(dian)(dian)(dian)(dian)(dian)(dian)樞繞組提供雙向(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)通路，Ui的(de)(de)(de)大小和(he)(he)極性決定了驅動(dong)(dong)轉矩(ju)的(de)(de)(de)數值和(he)(he)方向(xiang)，即車輛是(shi)前(qian)進還是(shi)制動(dong)(dong)。電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)負反(fan)饋保證(zheng)電(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)轉矩(ju)跟隨給定指令Ui變(bian)化，可(ke)有(you)(you)效(xiao)地提高車輛的(de)(de)(de)運動(dong)(dong)可(ke)控(kong)性。限(xian)于目前(qian)電(dian)(dian)(dian)(dian)(dian)(dian)池的(de)(de)(de)儲能(neng)水平，在(zai)(zai)電(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)自(zi)行車上采用再(zai)生制動(dong)(dong)技(ji)術(shu)是(shi)增加(jia)一次充電(dian)(dian)(dian)(dian)(dian)(dian)續(xu)駛里程的(de)(de)(de)有(you)(you)效(xiao)方法。該技(ji)術(shu)目前(qian)還處(chu)于研究開發階段(duan)。

     3、減速(su)系統(tong)的作用

     對(dui)于(yu)(yu)相同功率(lv)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)，額定(ding)轉速(su)(su)(su)越高(gao)，其額定(ding)轉矩和對(dui)應的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)樞(shu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流就越小(xiao)，減(jian)小(xiao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)樞(shu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流可(ke)降低(di)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)的(de)(de)(de)(de)銅耗和渦流損耗，提高(gao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)效率(lv)。采(cai)用配有減(jian)速(su)(su)(su)裝置的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)氣傳動(dong)(dong)系統(tong)，可(ke)改善電(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)自行(xing)(xing)車的(de)(de)(de)(de)低(di)速(su)(su)(su)動(dong)(dong)力性能，保證電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)始終工作在(zai)高(gao)速(su)(su)(su)、高(gao)效狀態，蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)處于(yu)(yu)小(xiao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)(de)最佳工況(kuang)，帶有減(jian)速(su)(su)(su)系統(tong)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)是將(jiang)機(ji)(ji)(ji)械減(jian)速(su)(su)(su)裝置和電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)合(he)成一(yi)體化的(de)(de)(de)(de)含油(you)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)輪毅。直(zhi)接(jie)車輪驅(qu)動(dong)(dong)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)自行(xing)(xing)車采(cai)用低(di)速(su)(su)(su)大(da)轉矩電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)，車輛低(di)速(su)(su)(su)前行(xing)(xing)時，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)樞(shu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流增大(da)，效率(lv)降低(di)；蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流大(da)，直(zhi)接(jie)影(ying)響蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)(de)(de)使用壽命(ming)。但直(zhi)接(jie)車輪驅(qu)動(dong)(dong)方式結(jie)構簡單(dan)，價格便宜，在(zai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)自行(xing)(xing)車上被(bei)廣泛采(cai)用。　

     蓄電池(chi)及其(qi)應用(yong)技術

     1、蓄電(dian)池

     蓄(xu)電(dian)(dian)池及其應用水平始終(zhong)是制約包(bao)括電(dian)(dian)動(dong)自行車在內的電(dian)(dian)動(dong)車輛進步的瓶頸。世界各(ge)主要工業(ye)國(guo)家(jia)紛紛投入巨大的人力、物力、財力開發高能(neng)量、低價格的蓄(xu)電(dian)(dian)池，日前已達到(dao)實用程度的新型蓄(xu)電(dian)(dian)池性能(neng)比(bi)較(jiao)見表一。

     鉛(qian)(qian)酸蓄(xu)電(dian)(dian)池(chi)不適(shi)合大功率(lv)連續放(fang)電(dian)(dian)，成組一(yi)致(zhi)性(xing)差(cha)，深(shen)度循環會降低能量轉換率(lv)和(he)縮短使用壽命(ming)，但它的(de)價(jia)格優勢是無可(ke)辯駁(bo)的(de)。并且改進后的(de)免(mian)維護(hu)全密封閥(fa)控式鉛(qian)(qian)酸蓄(xu)電(dian)(dian)池(chi)，其(qi)比能量、比功率(lv)、快速(su)充電(dian)(dian)性(xing)能等指(zhi)標均較傳統的(de)鉛(qian)(qian)酸蓄(xu)電(dian)(dian)池(chi)有大幅度提(ti)高，因此鉛(qian)(qian)酸蓄(xu)電(dian)(dian)池(chi)仍是我國電(dian)(dian)動自行車目前的(de)首選動力源。

     電(dian)(dian)動車對蓄電(dian)(dian)池的(de)主(zhu)要要求(qiu)是；高能量密度，使電(dian)(dian)動車有較長的(de)一次(ci)充電(dian)(dian)續(xu)駛里程；高功率密度，賦予電(dian)(dian)動車良好的(de)起動、加(jia)速、爬坡性能；長壽命，可有效降低

表一：

特? 性

鉛酸型電池

?鎘鎳電池

?氫鎳電池

鋰離子電池

比能量/Wh.kg-1

35

55

60

120

能量密度(du)/Wh.L-1

65

85

140

250

單元電壓/V?

2.0

1.2

1.2

3.7

放電曲線

平坦

平坦

平坦

平坦

循環壽命/次

150~140

500~1000

500~1000

?600~1000

月自放電率/%

6

15

25

5

制造(zao)成本(ben)/（美元/kWh）

75-150

100-200??

230-500

120-200

記憶效應??

?有

?有

無

無

環境保護

有污染

有污染

?無污染

?無污染

安全性

安全

安全

安全

潛在問題

研制生產情況

生產中

生產中

生產中

實驗中

     車輛的(de)(de)運行成(cheng)本。目前(qian)還沒有(you)一種蓄(xu)電(dian)(dian)(dian)池(chi)(chi)(chi)能夠全面滿足上(shang)述要求，但近年來突飛猛(meng)進的(de)(de)蓄(xu)電(dian)(dian)(dian)池(chi)(chi)(chi)制造技術向人們推出了各具特色(se)的(de)(de)新(xin)型電(dian)(dian)(dian)池(chi)(chi)(chi)，如：比能量80Wh/kg、比功率(lv)100W／kg的(de)(de)鈉硫電(dian)(dian)(dian)池(chi)(chi)(chi)，重(zhong)量輕、功率(lv)密度(du)大(da)的(de)(de)鋰(li)電(dian)(dian)(dian)池(chi)(chi)(chi)，可(ke)以“再(zai)生”方式置(zhi)換(huan)陽極(ji)電(dian)(dian)(dian)極(ji)的(de)(de)鋅(xin)―空氣(qi)電(dian)(dian)(dian)池(chi)(chi)(chi)，以及能量轉換(huan)效率(lv)高達80％的(de)(de)燃料電(dian)(dian)(dian)池(chi)(chi)(chi)。這些新(xin)型電(dian)(dian)(dian)池(chi)(chi)(chi)的(de)(de)出現打破了鉛(qian)酸(suan)蓄(xu)電(dian)(dian)(dian)池(chi)(chi)(chi)一統天下的(de)(de)格局，正(zheng)如美國(guo)先進電(dian)(dian)(dian)池(chi)(chi)(chi)聯合體(usABc)預言的(de)(de)那(nei)樣：鉛(qian)酸(suan)電(dian)(dian)(dian)池(chi)(chi)(chi)是(shi)成(cheng)熟的(de)(de)，但其(qi)性能提高的(de)(de)潛(qian)力有(you)限，氫(qing)鎳電(dian)(dian)(dian)池(chi)(chi)(chi)是(shi)一種較(jiao)好的(de)(de)中期解決方案，而鋰(li)電(dian)(dian)(dian)池(chi)(chi)(chi)則是(shi)未來的(de)(de)希望。

     2、電池應用技術

     1967年由美國科學家J．A．Mas提出了蓄電池充電器的麥氏三定律，從而奠定了電池充電器的(de)(de)理(li)論基(ji)礎(chu)。以此(ci)為基(ji)礎(chu)，人們建立了(le)脈(mo)沖(chong)去極(ji)化充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)方(fang)式(shi)，其核(he)心思想是(shi)在電(dian)(dian)(dian)(dian)(dian)池充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)前和充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)過程(cheng)中(zhong)適時地加入(ru)放電(dian)(dian)(dian)(dian)(dian)脈(mo)沖(chong)，消除電(dian)(dian)(dian)(dian)(dian)池的(de)(de)極(ji)化電(dian)(dian)(dian)(dian)(dian)壓。實踐證明(ming)：與傳統充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)方(fang)式(shi)相(xiang)比，采用脈(mo)沖(chong)去極(ji)化充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)方(fang)式(shi)不但(dan)可以實現快(kuai)充(chong)(chong)(chong)(chong)(chong)而且電(dian)(dian)(dian)(dian)(dian)池循環壽命會延長(chang)。因此(ci)，脈(mo)沖(chong)去極(ji)化充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)方(fang)式(shi)成(cheng)為快(kuai)速充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)技術的(de)(de)主流(liu)方(fang)式(shi)。美國、英國、加拿大等國家在20世紀(ji)80年代(dai)初(chu)就研制(zhi)出了(le)由微機控制(zhi)的(de)(de)，可向(xiang)電(dian)(dian)(dian)(dian)(dian)動(dong)(dong)自行車、電(dian)(dian)(dian)(dian)(dian)動(dong)(dong)汽車提供應急充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)服務(wu)的(de)(de)公用充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)站。雖然目前還沒有關(guan)于超快(kuai)速充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)的(de)(de)行業標(biao)準，但(dan)公認的(de)(de)準則是(shi)在15min內向(xiang)電(dian)(dian)(dian)(dian)(dian)他補充(chong)(chong)(chong)(chong)(chong)30％-50％的(de)(de)電(dian)(dian)(dian)(dian)(dian)量，30min內補充(chong)(chong)(chong)(chong)(chong)80％的(de)(de)電(dian)(dian)(dian)(dian)(dian)量760min內完全充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)。例如：加拿大Norvik。

     Traction的快速充(chong)電(dian)(dian)機，最大輸出功(gong)率150kW，可(ke)以(yi)(yi)同時(shi)給6個電(dian)(dian)動汽車(che)充(chong)電(dian)(dian)，15min內給電(dian)(dian)池補充(chong)50％的電(dian)(dian)量，其價格約10萬(wan)美元(yuan)。目前我(wo)國還沒有實用(yong)化的公用(yong)充(chong)電(dian)(dian)站，與電(dian)(dian)動自行車(che)電(dian)(dian)池配(pei)套使用(yong)的電(dian)(dian)動車(che)充(chong)電(dian)(dian)器以(yi)(yi)家用(yong)夜充(chong)型為主，充(chong)電(dian)(dian)時(shi)間8-10h，快速充(chong)電(dian)(dian)器充(chong)電(dian)(dian)時(shi)間2-4h。

     電池電量檢測和電池能量管理系統是繼電池充電器充電(dian)(dian)(dian)技術(shu)之后，電(dian)(dian)(dian)池應(ying)用(yong)中(zhong)的(de)(de)(de)另兩個主(zhu)要問題(ti)。車(che)(che)(che)載(zai)(zai)電(dian)(dian)(dian)池電(dian)(dian)(dian)員檢測系(xi)(xi)統(tong)(tong)既有傳統(tong)(tong)燃油汽車(che)(che)(che)的(de)(de)(de)油量計作(zuo)用(yong)，又有防止電(dian)(dian)(dian)池過充、過放的(de)(de)(de)監測環節。用(yong)于電(dian)(dian)(dian)動車(che)(che)(che)車(che)(che)(che)輛的(de)(de)(de)電(dian)(dian)(dian)池能(neng)量管(guan)理(li)(li)系(xi)(xi)統(tong)(tong)的(de)(de)(de)作(zuo)用(yong)有：(1)對車(che)(che)(che)載(zai)(zai)用(yong)電(dian)(dian)(dian)系(xi)(xi)統(tong)(tong)進(jin)行管(guan)制，達到電(dian)(dian)(dian)能(neng)合理(li)(li)分(fen)配使用(yong)，最終(zhong)實(shi)現(xian)節能(neng)目的(de)(de)(de)；(2)監控電(dian)(dian)(dian)池的(de)(de)(de)工(gong)作(zuo)狀態，防止電(dian)(dian)(dian)池過充、過放，及時(shi)發現(xian)嚴(yan)重(zhong)損壞的(de)(de)(de)單元(yuan)電(dian)(dian)(dian)池，并采取(qu)應(ying)急措施防止故障擴大；(3)記錄無放電(dian)(dian)(dian)數據，實(shi)現(xian)優化充電(dian)(dian)(dian)。

     國內外電動自(zi)行車

     性能(neng)比較

     電(dian)動(dong)(dong)自(zi)(zi)行(xing)車是(shi)全(quan)(quan)世界電(dian)動(dong)(dong)車輛(liang)工業中發展最快的(de)(de)(de)(de)。目(mu)前，日本(ben)的(de)(de)(de)(de)松下(xia)、三菱重工、雅(ya)馬哈(ha)、本(ben)田，德國(guo)的(de)(de)(de)(de)奔馳、大眾，美(mei)國(guo)的(de)(de)(de)(de)艾科卡等(deng)已致力(li)(li)(li)于電(dian)動(dong)(dong)自(zi)(zi)行(xing)車的(de)(de)(de)(de)規(gui)模(mo)化(hua)生產。其產品以助力(li)(li)(li)型(power asistant system，簡稱PAs)為(wei)主，pas的(de)(de)(de)(de)特點是(shi)把人(ren)力(li)(li)(li)與(yu)電(dian)能(neng)在(zai)(zai)不需(xu)要特殊操作的(de)(de)(de)(de)情況下(xia)巧妙(miao)地結合(he)起(qi)來：當車速小于20km／h的(de)(de)(de)(de)，助力(li)(li)(li)比為(wei)1：1；車速大于20km／h時電(dian)動(dong)(dong)車自(zi)(zi)動(dong)(dong)切斷電(dian)源，車輛(liang)依靠人(ren)力(li)(li)(li)騎(qi)行(xing)。顯(xian)然助力(li)(li)(li)系統的(de)(de)(de)(de)目(mu)的(de)(de)(de)(de)不在(zai)(zai)于提高(gao)速度，而(er)是(shi)在(zai)(zai)保(bao)(bao)證安(an)全(quan)(quan)的(de)(de)(de)(de)前提下(xia)通過減小騎(qi)行(xing)負荷達(da)到(dao)(dao)節(jie)約騎(qi)車人(ren)體力(li)(li)(li)的(de)(de)(de)(de)目(mu)的(de)(de)(de)(de)。我國(guo)電(dian)動(dong)(dong)自(zi)(zi)行(xing)車以全(quan)(quan)電(dian)動(dong)(dong)型為(wei)主，其主要參數為(wei)最高(gao)時速20km/h、工作電(dian)壓24v/36v，一(yi)次(ci)無(wu)電(dian)續駛(shi)里程40-55km，整(zheng)車重量35-38kg，電(dian)機(ji)(ji)功率130-180W，電(dian)機(ji)(ji)普遍采(cai)用永磁無(wu)刷直流(liu)(liu)電(dian)機(ji)(ji)，其控制器(qi)選用功率MosFET為(wei)主開關管，具(ju)有限(xian)流(liu)(liu)、欠(qian)壓、電(dian)機(ji)(ji)過熱和(he)剎車斷電(dian)等(deng)保(bao)(bao)護功能(neng)。縱觀(guan)國(guo)內外電(dian)動(dong)(dong)自(zi)(zi)行(xing)車的(de)(de)(de)(de)發展情況，就電(dian)動(dong)(dong)車自(zi)(zi)身而(er)言，國(guo)產車、進口(kou)車并無(wu)明(ming)顯(xian)差距，但國(guo)產電(dian)動(dong)(dong)自(zi)(zi)行(xing)車有明(ming)顯(xian)的(de)(de)(de)(de)價格優勢，一(yi)般在(zai)(zai)人(ren)民幣3000-4000元(yuan)/輛(liang)，而(er)美(mei)國(guo)達(da)到(dao)(dao)1800美(mei)元(yuan)/輛(liang)，歐(ou)洲達(da)2000美(mei)元(yuan)/輛(liang)，日本(ben)650-1500美(mei)元(yuan)/輛(liang)。

     我國(guo)電(dian)動(dong)自行(xing)車產業的(de)(de)發展有別于(yu)其它家電(dian)行(xing)業，它一開始就在(zai)走(zou)國(guo)產化的(de)(de)道路。中(zhong)國(guo)的(de)(de)電(dian)動(dong)自行(xing)車有著光明的(de)(de)市(shi)(shi)場前景。相信隨著電(dian)池(chi)儲能(neng)技(ji)術(shu)的(de)(de)改進和應用水(shui)平的(de)(de)提高，電(dian)動(dong)自行(xing)車一定能(neng)成為(wei)城市(shi)(shi)綠色代(dai)步(bu)工(gong)具(ju)。