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的發明，為電動自行車最終取代燃油助(zhu)動車提供了樂觀的保證。

     電氣傳動(dong)系統

     1、電(dian)動(dong)自行車對電(dian)氣傳動(dong)系統的(de)要求

     電(dian)氣傳(chuan)動(dong)系統是電(dian)動(dong)自(zi)行(xing)車的驅動(dong)和控制中心(xin)，其(qi)系統結(jie)構如圖1所(suo)示。對其(qi)要求是：結(jie)構簡單(dan)，外形尺寸小(xiao)(xiao)，重量(liang)輕，效率(lv)高，免維護或少維護。電(dian)動(dong)自(zi)行(xing)車的電(dian)機應具(ju)有高功率(lv)密度和圖2所(suo)示的矩―轉(zhuan)(zhuan)速(su)特(te)性(xing)：基(ji)速(su)以(yi)下大轉(zhuan)(zhuan)矩，適應車輛負(fu)荷(he)爬(pa)坡(po)、頻繁起制動(dong)等要求；基(ji)速(su)以(yi)上小(xiao)(xiao)轉(zhuan)(zhuan)矩、恒功率(lv)，保證(zheng)車輛在(zai)平坦(tan)路面上快(kuai)速(su)騎行(xing)。同時，電(dian)機在(zai)整個轉(zhuan)(zhuan)矩―轉(zhuan)(zhuan)速(su)運行(xing)范圍內應保持高效率(lv)，以(yi)謀(mou)求電(dian)池一次充電(dian)后的續(xu)駛里程盡可能長。2、無刷直流電(dian)機的控制規律

     無刷直(zhi)(zhi)流(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)具有很高(gao)的(de)(de)(de)(de)能(neng)量密度，其(qi)體積僅為相同(tong)功率普通直(zhi)(zhi)流(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)的(de)(de)(de)(de)50％，且重量輕、效(xiao)率高(gao)。用(yong)(yong)于(yu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)自行(xing)車(che)的(de)(de)(de)(de)永磁(ci)無刷直(zhi)(zhi)流(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)有兩類：內轉子和(he)外(wai)轉子，其(qi)中外(wai)轉子電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)更適(shi)合構成(cheng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)輪(lun)毅，在電(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)自行(xing)車(che)中有較多應用(yong)(yong)。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)自行(xing)車(che)主要在市區騎行(xing)，車(che)速不高(gao)，并(bing)且起、停頻繁(fan)，因此電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)普遍采用(yong)(yong)多極三(san)相結(jie)構。控(kong)(kong)制(zhi)(zhi)器(qi)(qi)(qi)為雙向DC／AC變(bian)流(liu)(liu)(liu)器(qi)(qi)(qi)，車(che)輛前(qian)(qian)進(jin)時(shi)(shi)，變(bian)流(liu)(liu)(liu)器(qi)(qi)(qi)控(kong)(kong)制(zhi)(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)工(gong)(gong)(gong)作在電(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)工(gong)(gong)(gong)況；車(che)輛制(zhi)(zhi)動(dong)時(shi)(shi)，變(bian)流(liu)(liu)(liu)器(qi)(qi)(qi)控(kong)(kong)制(zhi)(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)工(gong)(gong)(gong)作在發電(dian)(dian)(dian)(dian)(dian)(dian)(dian)工(gong)(gong)(gong)況，實現(xian)再(zai)生(sheng)制(zhi)(zhi)動(dong)，將機(ji)(ji)械(xie)能(neng)轉換(huan)成(cheng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)能(neng)反饋(kui)回蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池。圖(tu)3是由(you)變(bian)流(liu)(liu)(liu)器(qi)(qi)(qi)、轉子位置檢測器(qi)(qi)(qi)和(he)永磁(ci)同(tong)步電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)構成(cheng)的(de)(de)(de)(de)永磁(ci)無刷直(zhi)(zhi)流(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)原理圖(tu)。其(qi)中變(bian)流(liu)(liu)(liu)器(qi)(qi)(qi)為電(dian)(dian)(dian)(dian)(dian)(dian)(dian)樞繞組提供(gong)雙向電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)通路，Ui的(de)(de)(de)(de)大小和(he)極性決定(ding)(ding)了(le)驅動(dong)轉矩的(de)(de)(de)(de)數值(zhi)和(he)方向，即車(che)輛是前(qian)(qian)進(jin)還是制(zhi)(zhi)動(dong)。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)負反饋(kui)保證(zheng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)磁(ci)轉矩跟隨(sui)給定(ding)(ding)指令Ui變(bian)化，可(ke)有效(xiao)地提高(gao)車(che)輛的(de)(de)(de)(de)運動(dong)可(ke)控(kong)(kong)性。限于(yu)目(mu)前(qian)(qian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池的(de)(de)(de)(de)儲能(neng)水平(ping)，在電(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)自行(xing)車(che)上采用(yong)(yong)再(zai)生(sheng)制(zhi)(zhi)動(dong)技術是增加(jia)一(yi)次充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)續駛里程的(de)(de)(de)(de)有效(xiao)方法(fa)。該技術目(mu)前(qian)(qian)還處于(yu)研究開發階段。

     3、減速系統的作用

     對于(yu)(yu)相同(tong)功率(lv)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)，額定轉速(su)越高，其額定轉矩(ju)和(he)對應的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)樞(shu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流就越小(xiao)，減小(xiao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)樞(shu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流可(ke)降低(di)(di)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)的(de)(de)(de)(de)銅耗(hao)和(he)渦流損(sun)耗(hao)，提高電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)效(xiao)率(lv)。采用配有減速(su)裝置(zhi)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)氣傳動(dong)(dong)(dong)系(xi)統(tong)，可(ke)改(gai)善電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)自行(xing)車(che)(che)(che)的(de)(de)(de)(de)低(di)(di)速(su)動(dong)(dong)(dong)力性能，保證電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)始終(zhong)工作在(zai)高速(su)、高效(xiao)狀態，蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池處于(yu)(yu)小(xiao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)(de)最佳工況，帶有減速(su)系(xi)統(tong)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)是將機(ji)械減速(su)裝置(zhi)和(he)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)合(he)成一(yi)體化的(de)(de)(de)(de)含(han)油(you)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)輪毅。直(zhi)(zhi)接(jie)車(che)(che)(che)輪驅動(dong)(dong)(dong)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)自行(xing)車(che)(che)(che)采用低(di)(di)速(su)大(da)轉矩(ju)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)，車(che)(che)(che)輛低(di)(di)速(su)前(qian)行(xing)時，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)樞(shu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流增(zeng)大(da)，效(xiao)率(lv)降低(di)(di)；蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流大(da)，直(zhi)(zhi)接(jie)影響(xiang)蓄電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池的(de)(de)(de)(de)使用壽命(ming)。但直(zhi)(zhi)接(jie)車(che)(che)(che)輪驅動(dong)(dong)(dong)方式(shi)結構簡(jian)單(dan)，價格便宜(yi)，在(zai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)自行(xing)車(che)(che)(che)上被廣泛(fan)采用。　

     蓄電池及其應用技術

     1、蓄電池

     蓄電池及其應(ying)用(yong)水平始終(zhong)是制約包括(kuo)電動自(zi)行車在內的(de)(de)(de)電動車輛進(jin)步的(de)(de)(de)瓶頸。世(shi)界(jie)各(ge)主要(yao)工業國(guo)家紛(fen)紛(fen)投入(ru)巨(ju)大(da)的(de)(de)(de)人力、物(wu)力、財(cai)力開發高能(neng)量、低價格的(de)(de)(de)蓄電池，日(ri)前已(yi)達到實用(yong)程度(du)的(de)(de)(de)新型蓄電池性(xing)能(neng)比較見表一。

     鉛酸蓄(xu)(xu)電(dian)池(chi)不適合大(da)(da)功(gong)率連續(xu)放電(dian)，成(cheng)組一致性差，深(shen)度循環會降低能量(liang)轉(zhuan)換率和縮短使用壽命，但(dan)它的(de)(de)價(jia)格優勢是無(wu)可辯駁的(de)(de)。并(bing)且改進后的(de)(de)免維護全密封閥控式(shi)鉛酸蓄(xu)(xu)電(dian)池(chi)，其比能量(liang)、比功(gong)率、快(kuai)速充電(dian)性能等指標均較傳統的(de)(de)鉛酸蓄(xu)(xu)電(dian)池(chi)有(you)大(da)(da)幅度提高，因此(ci)鉛酸蓄(xu)(xu)電(dian)池(chi)仍是我(wo)國電(dian)動自行車目前的(de)(de)首選動力源。

     電動(dong)車對蓄(xu)電池的主要要求(qiu)是；高(gao)能(neng)量密度(du)，使電動(dong)車有較長(chang)的一次充電續駛里程；高(gao)功率密度(du)，賦予電動(dong)車良(liang)好的起動(dong)、加速(su)、爬(pa)坡性能(neng)；長(chang)壽(shou)命，可有效(xiao)降(jiang)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(liang)/Wh.kg-1

35

55

60

120

能量密度/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(xing)成本(ben)。目前還沒有一種蓄(xu)電(dian)(dian)(dian)池(chi)(chi)(chi)能(neng)夠全面滿足上(shang)述要求，但(dan)近年來突飛猛進的(de)(de)蓄(xu)電(dian)(dian)(dian)池(chi)(chi)(chi)制造技術向人(ren)們推出了各具特(te)色的(de)(de)新(xin)型電(dian)(dian)(dian)池(chi)(chi)(chi)，如(ru)：比(bi)能(neng)量80Wh/kg、比(bi)功(gong)率100W／kg的(de)(de)鈉硫電(dian)(dian)(dian)池(chi)(chi)(chi)，重量輕(qing)、功(gong)率密(mi)度(du)大的(de)(de)鋰電(dian)(dian)(dian)池(chi)(chi)(chi)，可以“再(zai)生”方式(shi)置換陽極電(dian)(dian)(dian)極的(de)(de)鋅(xin)―空氣電(dian)(dian)(dian)池(chi)(chi)(chi)，以及能(neng)量轉換效率高(gao)達80％的(de)(de)燃料電(dian)(dian)(dian)池(chi)(chi)(chi)。這(zhe)些新(xin)型電(dian)(dian)(dian)池(chi)(chi)(chi)的(de)(de)出現打破(po)了鉛(qian)酸蓄(xu)電(dian)(dian)(dian)池(chi)(chi)(chi)一統天下的(de)(de)格局，正(zheng)如(ru)美國先進電(dian)(dian)(dian)池(chi)(chi)(chi)聯合(he)體(usABc)預言的(de)(de)那(nei)樣：鉛(qian)酸電(dian)(dian)(dian)池(chi)(chi)(chi)是(shi)成熟的(de)(de)，但(dan)其性能(neng)提高(gao)的(de)(de)潛力有限，氫鎳(nie)電(dian)(dian)(dian)池(chi)(chi)(chi)是(shi)一種較好的(de)(de)中(zhong)期解決方案，而鋰電(dian)(dian)(dian)池(chi)(chi)(chi)則是(shi)未來的(de)(de)希望。

     2、電(dian)池應用(yong)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)理論基礎(chu)。以此為基礎(chu)，人們建(jian)立了脈(mo)(mo)沖(chong)去(qu)極化(hua)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)方(fang)式(shi)，其核心思想是在(zai)電(dian)(dian)(dian)(dian)池充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)前和充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)過程中適時(shi)地加(jia)入放電(dian)(dian)(dian)(dian)脈(mo)(mo)沖(chong)，消除電(dian)(dian)(dian)(dian)池的(de)(de)極化(hua)電(dian)(dian)(dian)(dian)壓。實踐證明：與(yu)傳統充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)方(fang)式(shi)相比，采用脈(mo)(mo)沖(chong)去(qu)極化(hua)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)方(fang)式(shi)不但可以實現快充(chong)(chong)(chong)而(er)且電(dian)(dian)(dian)(dian)池循環壽(shou)命會(hui)延長(chang)。因(yin)此，脈(mo)(mo)沖(chong)去(qu)極化(hua)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)方(fang)式(shi)成為快速充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)技術的(de)(de)主流方(fang)式(shi)。美(mei)國(guo)(guo)、英國(guo)(guo)、加(jia)拿(na)大(da)等國(guo)(guo)家在(zai)20世紀(ji)80年(nian)代初就(jiu)研(yan)制(zhi)出了由(you)微機(ji)控制(zhi)的(de)(de)，可向電(dian)(dian)(dian)(dian)動自行車、電(dian)(dian)(dian)(dian)動汽(qi)車提供應急充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)服務(wu)的(de)(de)公用充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)站。雖然目前還(huan)沒有關(guan)于超快速充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)的(de)(de)行業標準(zhun)，但公認的(de)(de)準(zhun)則是在(zai)15min內向電(dian)(dian)(dian)(dian)他(ta)補(bu)充(chong)(chong)(chong)30％-50％的(de)(de)電(dian)(dian)(dian)(dian)量，30min內補(bu)充(chong)(chong)(chong)80％的(de)(de)電(dian)(dian)(dian)(dian)量760min內完(wan)全充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)。例如(ru)：加(jia)拿(na)大(da)Norvik。

     Traction的(de)快速充(chong)(chong)(chong)電(dian)(dian)機，最大輸出功率(lv)150kW，可以同時給6個電(dian)(dian)動(dong)(dong)汽(qi)車充(chong)(chong)(chong)電(dian)(dian)，15min內(nei)給電(dian)(dian)池補(bu)充(chong)(chong)(chong)50％的(de)電(dian)(dian)量，其價格約10萬美元。目前我(wo)國還沒有實(shi)用(yong)化的(de)公用(yong)充(chong)(chong)(chong)電(dian)(dian)站，與電(dian)(dian)動(dong)(dong)自行車電(dian)(dian)池配套使用(yong)的(de)電(dian)(dian)動(dong)(dong)車充(chong)(chong)(chong)電(dian)(dian)器以家用(yong)夜充(chong)(chong)(chong)型為主，充(chong)(chong)(chong)電(dian)(dian)時間8-10h，快速充(chong)(chong)(chong)電(dian)(dian)器充(chong)(chong)(chong)電(dian)(dian)時間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)(dian)(dian)技術之(zhi)后，電(dian)(dian)(dian)(dian)(dian)池(chi)應用(yong)中的(de)(de)(de)另兩個主要問題。車(che)(che)載(zai)電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)員檢測系(xi)統既有(you)(you)傳(chuan)統燃油汽車(che)(che)的(de)(de)(de)油量計作用(yong)，又有(you)(you)防止(zhi)電(dian)(dian)(dian)(dian)(dian)池(chi)過充、過放(fang)的(de)(de)(de)監測環(huan)節。用(yong)于電(dian)(dian)(dian)(dian)(dian)動車(che)(che)車(che)(che)輛的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)池(chi)能量管理系(xi)統的(de)(de)(de)作用(yong)有(you)(you)：(1)對車(che)(che)載(zai)用(yong)電(dian)(dian)(dian)(dian)(dian)系(xi)統進行管制，達(da)到電(dian)(dian)(dian)(dian)(dian)能合理分配使用(yong)，最終實現節能目的(de)(de)(de)；(2)監控電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)工作狀態，防止(zhi)電(dian)(dian)(dian)(dian)(dian)池(chi)過充、過放(fang)，及時發現嚴重損壞的(de)(de)(de)單元電(dian)(dian)(dian)(dian)(dian)池(chi)，并采(cai)取應急措施防止(zhi)故障擴大；(3)記錄無放(fang)電(dian)(dian)(dian)(dian)(dian)數據，實現優化充電(dian)(dian)(dian)(dian)(dian)。

     國(guo)內外電動自行車

     性(xing)能比較

     電(dian)動(dong)(dong)自(zi)行(xing)(xing)(xing)車(che)是(shi)(shi)全世界電(dian)動(dong)(dong)車(che)輛工(gong)業中發展最(zui)快的(de)(de)(de)。目前(qian)，日(ri)本(ben)的(de)(de)(de)松(song)下(xia)、三菱重工(gong)、雅(ya)馬哈、本(ben)田，德國的(de)(de)(de)奔馳(chi)、大眾，美(mei)國的(de)(de)(de)艾科卡等(deng)已致力于(yu)電(dian)動(dong)(dong)自(zi)行(xing)(xing)(xing)車(che)的(de)(de)(de)規(gui)模化生產(chan)(chan)。其產(chan)(chan)品以(yi)助(zhu)力型(power asistant system，簡稱(cheng)PAs)為主(zhu)，pas的(de)(de)(de)特(te)點是(shi)(shi)把人力與(yu)電(dian)能在(zai)不(bu)需要(yao)特(te)殊操作(zuo)的(de)(de)(de)情況下(xia)巧妙(miao)地結合(he)起來：當(dang)車(che)速(su)小(xiao)(xiao)于(yu)20km／h的(de)(de)(de)，助(zhu)力比為1：1；車(che)速(su)大于(yu)20km／h時(shi)電(dian)動(dong)(dong)車(che)自(zi)動(dong)(dong)切斷電(dian)源，車(che)輛依靠人力騎(qi)行(xing)(xing)(xing)。顯然助(zhu)力系統(tong)的(de)(de)(de)目的(de)(de)(de)不(bu)在(zai)于(yu)提(ti)高速(su)度，而(er)是(shi)(shi)在(zai)保證安(an)全的(de)(de)(de)前(qian)提(ti)下(xia)通(tong)過減小(xiao)(xiao)騎(qi)行(xing)(xing)(xing)負荷達(da)(da)到節約騎(qi)車(che)人體(ti)力的(de)(de)(de)目的(de)(de)(de)。我國電(dian)動(dong)(dong)自(zi)行(xing)(xing)(xing)車(che)以(yi)全電(dian)動(dong)(dong)型為主(zhu)，其主(zhu)要(yao)參數為最(zui)高時(shi)速(su)20km/h、工(gong)作(zuo)電(dian)壓24v/36v，一次(ci)無(wu)電(dian)續駛里程40-55km，整車(che)重量35-38kg，電(dian)機(ji)功率(lv)130-180W，電(dian)機(ji)普(pu)遍采(cai)用永磁無(wu)刷直流電(dian)機(ji)，其控制器選用功率(lv)MosFET為主(zhu)開關管，具有限流、欠壓、電(dian)機(ji)過熱(re)和剎車(che)斷電(dian)等(deng)保護功能。縱觀國內外電(dian)動(dong)(dong)自(zi)行(xing)(xing)(xing)車(che)的(de)(de)(de)發展情況，就(jiu)電(dian)動(dong)(dong)車(che)自(zi)身而(er)言，國產(chan)(chan)車(che)、進口(kou)車(che)并無(wu)明(ming)(ming)顯差(cha)距(ju)，但國產(chan)(chan)電(dian)動(dong)(dong)自(zi)行(xing)(xing)(xing)車(che)有明(ming)(ming)顯的(de)(de)(de)價格優勢，一般在(zai)人民幣3000-4000元/輛，而(er)美(mei)國達(da)(da)到1800美(mei)元/輛，歐洲達(da)(da)2000美(mei)元/輛，日(ri)本(ben)650-1500美(mei)元/輛。

     我國(guo)電動自行(xing)車(che)產(chan)業的(de)發(fa)展有(you)(you)別于其(qi)它(ta)家電行(xing)業，它(ta)一開始就(jiu)在走國(guo)產(chan)化的(de)道路。中國(guo)的(de)電動自行(xing)車(che)有(you)(you)著光明的(de)市場(chang)前(qian)景。相信隨(sui)著電池儲能技(ji)術的(de)改進和應用水(shui)平的(de)提(ti)高(gao)，電動自行(xing)車(che)一定能成(cheng)為城市綠色(se)代步工具。