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(wei)電(dian)動自行(xing)車最終取代燃油(you)助動車提供(gong)了樂觀的保證。

     電氣傳動(dong)系統

     1、電動(dong)自行車(che)對(dui)電氣傳動(dong)系統的(de)要求

     電氣傳動系統(tong)是電動自行車(che)的(de)(de)(de)驅動和控制(zhi)(zhi)(zhi)中心，其系統(tong)結構(gou)如圖1所示。對其要求是：結構(gou)簡(jian)單，外形尺寸(cun)小，重量輕，效(xiao)率(lv)(lv)高，免維(wei)(wei)護或少維(wei)(wei)護。電動自行車(che)的(de)(de)(de)電機(ji)應(ying)具(ju)有高功率(lv)(lv)密度和圖2所示的(de)(de)(de)矩―轉(zhuan)速(su)特性(xing)：基速(su)以(yi)下大轉(zhuan)矩，適應(ying)車(che)輛負荷爬坡、頻繁起制(zhi)(zhi)(zhi)動等要求；基速(su)以(yi)上小轉(zhuan)矩、恒(heng)功率(lv)(lv)，保證(zheng)車(che)輛在(zai)平(ping)坦路面上快速(su)騎行。同(tong)時，電機(ji)在(zai)整(zheng)個轉(zhuan)矩―轉(zhuan)速(su)運行范(fan)圍內應(ying)保持高效(xiao)率(lv)(lv)，以(yi)謀求電池一(yi)次充電后(hou)的(de)(de)(de)續駛里程盡可(ke)能長。2、無(wu)刷直(zhi)流電機(ji)的(de)(de)(de)控制(zhi)(zhi)(zhi)規律(lv)

     無刷直(zhi)(zhi)(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)機(ji)具有(you)很(hen)高(gao)的(de)能量密(mi)度(du)，其(qi)體積僅為相(xiang)同功(gong)率普通直(zhi)(zhi)(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)機(ji)的(de)50％，且重量輕、效(xiao)率高(gao)。用(yong)于(yu)電(dian)(dian)(dian)(dian)動(dong)(dong)自行(xing)車(che)(che)(che)(che)(che)的(de)永(yong)磁無刷直(zhi)(zhi)(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)機(ji)有(you)兩類：內轉(zhuan)(zhuan)子(zi)(zi)和外轉(zhuan)(zhuan)子(zi)(zi)，其(qi)中外轉(zhuan)(zhuan)子(zi)(zi)電(dian)(dian)(dian)(dian)機(ji)更適(shi)合構成電(dian)(dian)(dian)(dian)動(dong)(dong)輪(lun)毅，在電(dian)(dian)(dian)(dian)動(dong)(dong)自行(xing)車(che)(che)(che)(che)(che)中有(you)較多(duo)應用(yong)。電(dian)(dian)(dian)(dian)動(dong)(dong)自行(xing)車(che)(che)(che)(che)(che)主(zhu)要在市區騎行(xing)，車(che)(che)(che)(che)(che)速不高(gao)，并且起、停頻繁，因此(ci)電(dian)(dian)(dian)(dian)機(ji)普遍采用(yong)多(duo)極三相(xiang)結構。控(kong)制(zhi)器(qi)(qi)為雙向(xiang)DC／AC變(bian)流(liu)(liu)(liu)(liu)(liu)(liu)器(qi)(qi)，車(che)(che)(che)(che)(che)輛前(qian)進時，變(bian)流(liu)(liu)(liu)(liu)(liu)(liu)器(qi)(qi)控(kong)制(zhi)電(dian)(dian)(dian)(dian)機(ji)工作(zuo)在電(dian)(dian)(dian)(dian)動(dong)(dong)工況(kuang)；車(che)(che)(che)(che)(che)輛制(zhi)動(dong)(dong)時，變(bian)流(liu)(liu)(liu)(liu)(liu)(liu)器(qi)(qi)控(kong)制(zhi)電(dian)(dian)(dian)(dian)機(ji)工作(zuo)在發電(dian)(dian)(dian)(dian)工況(kuang)，實現再生制(zhi)動(dong)(dong)，將機(ji)械能轉(zhuan)(zhuan)換成電(dian)(dian)(dian)(dian)能反(fan)饋(kui)回蓄電(dian)(dian)(dian)(dian)池(chi)。圖3是由(you)變(bian)流(liu)(liu)(liu)(liu)(liu)(liu)器(qi)(qi)、轉(zhuan)(zhuan)子(zi)(zi)位置檢測(ce)器(qi)(qi)和永(yong)磁同步電(dian)(dian)(dian)(dian)機(ji)構成的(de)永(yong)磁無刷直(zhi)(zhi)(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)機(ji)原(yuan)理(li)圖。其(qi)中變(bian)流(liu)(liu)(liu)(liu)(liu)(liu)器(qi)(qi)為電(dian)(dian)(dian)(dian)樞繞組提供雙向(xiang)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)(liu)通路，Ui的(de)大小(xiao)和極性決定了驅動(dong)(dong)轉(zhuan)(zhuan)矩的(de)數(shu)值和方(fang)向(xiang)，即車(che)(che)(che)(che)(che)輛是前(qian)進還(huan)是制(zhi)動(dong)(dong)。電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)(liu)負(fu)反(fan)饋(kui)保證電(dian)(dian)(dian)(dian)磁轉(zhuan)(zhuan)矩跟隨給定指令Ui變(bian)化，可有(you)效(xiao)地提高(gao)車(che)(che)(che)(che)(che)輛的(de)運動(dong)(dong)可控(kong)性。限于(yu)目(mu)前(qian)電(dian)(dian)(dian)(dian)池(chi)的(de)儲能水平，在電(dian)(dian)(dian)(dian)動(dong)(dong)自行(xing)車(che)(che)(che)(che)(che)上采用(yong)再生制(zhi)動(dong)(dong)技術是增(zeng)加一(yi)次充電(dian)(dian)(dian)(dian)續(xu)駛里程的(de)有(you)效(xiao)方(fang)法。該技術目(mu)前(qian)還(huan)處于(yu)研究開發階段。

     3、減速系統的作用

     對于相同功率(lv)(lv)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)，額定轉(zhuan)速越(yue)高(gao)，其額定轉(zhuan)矩(ju)和對應的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)樞電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)就越(yue)小，減(jian)(jian)(jian)小電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)樞電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)可(ke)降(jiang)低(di)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)的(de)(de)銅耗和渦流(liu)損耗，提高(gao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)效(xiao)率(lv)(lv)。采用配有減(jian)(jian)(jian)速裝(zhuang)置的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)氣傳動(dong)系統，可(ke)改善(shan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)自(zi)(zi)行車(che)(che)的(de)(de)低(di)速動(dong)力性能，保證電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)始終工(gong)作(zuo)在(zai)高(gao)速、高(gao)效(xiao)狀態，蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)處于小電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)最佳工(gong)況，帶有減(jian)(jian)(jian)速系統的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)是將機(ji)(ji)(ji)械減(jian)(jian)(jian)速裝(zhuang)置和電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)合成一(yi)體化的(de)(de)含油電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)輪毅。直接(jie)車(che)(che)輪驅動(dong)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)自(zi)(zi)行車(che)(che)采用低(di)速大轉(zhuan)矩(ju)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)，車(che)(che)輛低(di)速前行時，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)樞電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)增(zeng)大，效(xiao)率(lv)(lv)降(jiang)低(di)；蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)大，直接(jie)影響(xiang)蓄(xu)(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)使用壽命。但直接(jie)車(che)(che)輪驅動(dong)方式結構簡單，價格便宜，在(zai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)自(zi)(zi)行車(che)(che)上被廣泛采用。　

     蓄電池(chi)及其應用技(ji)術(shu)

     1、蓄電池(chi)

     蓄(xu)電(dian)池及(ji)其(qi)應(ying)用水平始終是制(zhi)約包括電(dian)動(dong)(dong)自行(xing)車在內的電(dian)動(dong)(dong)車輛進步的瓶(ping)頸。世界各主要工業(ye)國家紛(fen)紛(fen)投入巨大(da)的人(ren)力、物力、財力開發高能量(liang)、低價(jia)格的蓄(xu)電(dian)池，日前(qian)已達到實用程度的新型(xing)蓄(xu)電(dian)池性能比較見表一。

     鉛酸(suan)(suan)(suan)蓄(xu)電(dian)(dian)(dian)池(chi)不適合大功率(lv)連(lian)續放電(dian)(dian)(dian)，成組(zu)一致性(xing)差，深度循環會降(jiang)低能(neng)量(liang)轉換率(lv)和縮(suo)短使(shi)用(yong)壽命，但它(ta)的(de)(de)價格優(you)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(fa)控式鉛酸(suan)(suan)(suan)蓄(xu)電(dian)(dian)(dian)池(chi)，其(qi)比(bi)能(neng)量(liang)、比(bi)功率(lv)、快速充(chong)電(dian)(dian)(dian)性(xing)能(neng)等指標均較傳統的(de)(de)鉛酸(suan)(suan)(suan)蓄(xu)電(dian)(dian)(dian)池(chi)有大幅度提高，因此鉛酸(suan)(suan)(suan)蓄(xu)電(dian)(dian)(dian)池(chi)仍是我國(guo)電(dian)(dian)(dian)動自行(xing)車目前的(de)(de)首選(xuan)動力源。

     電(dian)(dian)動(dong)(dong)車(che)對蓄(xu)電(dian)(dian)池(chi)的主要要求是；高(gao)能量密度，使電(dian)(dian)動(dong)(dong)車(che)有較(jiao)長的一次充電(dian)(dian)續駛(shi)里程(cheng)；高(gao)功(gong)率密度，賦予電(dian)(dian)動(dong)(dong)車(che)良好的起動(dong)(dong)、加速、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/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(zhi)造成本/（美(mei)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)(de)(de)運行成本。目前還沒(mei)有一種(zhong)(zhong)蓄電(dian)池(chi)(chi)(chi)(chi)(chi)能夠(gou)全面滿(man)足上述要求，但近年(nian)來(lai)突(tu)飛猛進(jin)的(de)(de)(de)(de)蓄電(dian)池(chi)(chi)(chi)(chi)(chi)制造技術向人們推出了各(ge)具特色的(de)(de)(de)(de)新(xin)型電(dian)池(chi)(chi)(chi)(chi)(chi)，如：比能量(liang)80Wh/kg、比功(gong)率(lv)100W／kg的(de)(de)(de)(de)鈉(na)硫電(dian)池(chi)(chi)(chi)(chi)(chi)，重量(liang)輕、功(gong)率(lv)密度大的(de)(de)(de)(de)鋰(li)電(dian)池(chi)(chi)(chi)(chi)(chi)，可(ke)以(yi)“再生”方式(shi)置換陽極電(dian)極的(de)(de)(de)(de)鋅(xin)―空(kong)氣電(dian)池(chi)(chi)(chi)(chi)(chi)，以(yi)及(ji)能量(liang)轉換效率(lv)高(gao)達80％的(de)(de)(de)(de)燃料(liao)電(dian)池(chi)(chi)(chi)(chi)(chi)。這些新(xin)型電(dian)池(chi)(chi)(chi)(chi)(chi)的(de)(de)(de)(de)出現打破了鉛(qian)(qian)酸(suan)(suan)蓄電(dian)池(chi)(chi)(chi)(chi)(chi)一統天下的(de)(de)(de)(de)格局，正如美國先進(jin)電(dian)池(chi)(chi)(chi)(chi)(chi)聯合體(usABc)預言(yan)的(de)(de)(de)(de)那(nei)樣：鉛(qian)(qian)酸(suan)(suan)電(dian)池(chi)(chi)(chi)(chi)(chi)是成熟的(de)(de)(de)(de)，但其性能提高(gao)的(de)(de)(de)(de)潛力有限，氫鎳電(dian)池(chi)(chi)(chi)(chi)(chi)是一種(zhong)(zhong)較好的(de)(de)(de)(de)中期解決方案，而鋰(li)電(dian)池(chi)(chi)(chi)(chi)(chi)則是未來(lai)的(de)(de)(de)(de)希望。

     2、電(dian)池應用技(ji)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(wei)基礎(chu)，人們建(jian)立了(le)脈(mo)沖去極化充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)方(fang)式(shi)，其核心思(si)想(xiang)是(shi)在電(dian)(dian)(dian)(dian)(dian)池充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)前和充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)過程中適時地(di)加(jia)入放電(dian)(dian)(dian)(dian)(dian)脈(mo)沖，消除電(dian)(dian)(dian)(dian)(dian)池的(de)(de)極化電(dian)(dian)(dian)(dian)(dian)壓(ya)。實(shi)踐(jian)證明(ming)：與傳統充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)方(fang)式(shi)相比，采用脈(mo)沖去極化充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)方(fang)式(shi)不但可以實(shi)現快充(chong)(chong)(chong)而且電(dian)(dian)(dian)(dian)(dian)池循(xun)環壽命會延長。因(yin)此，脈(mo)沖去極化充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)方(fang)式(shi)成為(wei)快速(su)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)技術的(de)(de)主流方(fang)式(shi)。美國、英國、加(jia)拿大(da)等國家在20世紀(ji)80年代(dai)初就研制出了(le)由微機控(kong)制的(de)(de)，可向電(dian)(dian)(dian)(dian)(dian)動自行車、電(dian)(dian)(dian)(dian)(dian)動汽車提(ti)供(gong)應急充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)服務的(de)(de)公用充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)站。雖(sui)然目(mu)前還沒有關于超快速(su)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)的(de)(de)行業標準，但公認的(de)(de)準則是(shi)在15min內(nei)向電(dian)(dian)(dian)(dian)(dian)他補(bu)充(chong)(chong)(chong)30％-50％的(de)(de)電(dian)(dian)(dian)(dian)(dian)量，30min內(nei)補(bu)充(chong)(chong)(chong)80％的(de)(de)電(dian)(dian)(dian)(dian)(dian)量760min內(nei)完(wan)全充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)。例(li)如：加(jia)拿大(da)Norvik。

     Traction的(de)快速充電(dian)(dian)(dian)機，最(zui)大輸出功率150kW，可以同時給(gei)6個(ge)電(dian)(dian)(dian)動(dong)汽車(che)充電(dian)(dian)(dian)，15min內(nei)給(gei)電(dian)(dian)(dian)池(chi)補充50％的(de)電(dian)(dian)(dian)量，其價格約10萬美元。目前(qian)我國還(huan)沒有實用(yong)化的(de)公用(yong)充電(dian)(dian)(dian)站，與(yu)電(dian)(dian)(dian)動(dong)自行車(che)電(dian)(dian)(dian)池(chi)配套使用(yong)的(de)電(dian)(dian)(dian)動(dong)車(che)充電(dian)(dian)(dian)器(qi)以家用(yong)夜充型為(wei)主，充電(dian)(dian)(dian)時間(jian)8-10h，快速充電(dian)(dian)(dian)器(qi)充電(dian)(dian)(dian)時間(jian)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(chong)電(dian)(dian)(dian)(dian)技術之后，電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)應(ying)用(yong)中(zhong)的(de)另兩個主要問題。車載電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)電(dian)(dian)(dian)(dian)員檢(jian)測(ce)系統既(ji)有傳統燃油(you)(you)汽車的(de)油(you)(you)量計(ji)作用(yong)，又(you)有防(fang)止(zhi)電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)過(guo)充(chong)、過(guo)放(fang)的(de)監(jian)測(ce)環節(jie)。用(yong)于電(dian)(dian)(dian)(dian)動車車輛的(de)電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)能量管理(li)系統的(de)作用(yong)有：(1)對車載用(yong)電(dian)(dian)(dian)(dian)系統進行管制，達到電(dian)(dian)(dian)(dian)能合理(li)分配使用(yong)，最終實(shi)現(xian)節(jie)能目的(de)；(2)監(jian)控電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)工作狀態，防(fang)止(zhi)電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)過(guo)充(chong)、過(guo)放(fang)，及(ji)時發現(xian)嚴重損壞(huai)的(de)單元(yuan)電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)，并(bing)采取(qu)應(ying)急措施防(fang)止(zhi)故障擴大(da)；(3)記錄無放(fang)電(dian)(dian)(dian)(dian)數據(ju)，實(shi)現(xian)優化充(chong)電(dian)(dian)(dian)(dian)。

     國(guo)內外電(dian)動自行車(che)

     性(xing)能(neng)比較

     電(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)自(zi)行(xing)(xing)車(che)(che)是(shi)全世界電(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)車(che)(che)輛(liang)工(gong)業中發展(zhan)最(zui)(zui)快的(de)(de)。目前，日本的(de)(de)松下、三菱(ling)重工(gong)、雅馬哈、本田，德國的(de)(de)奔(ben)馳、大眾(zhong)，美(mei)國的(de)(de)艾(ai)科卡(ka)等(deng)已(yi)致力(li)于(yu)電(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)自(zi)行(xing)(xing)車(che)(che)的(de)(de)規模化生產(chan)。其產(chan)品以助力(li)型(power asistant system，簡稱(cheng)PAs)為(wei)(wei)主(zhu)，pas的(de)(de)特點是(shi)把人力(li)與電(dian)(dian)(dian)(dian)(dian)能(neng)在(zai)不需要(yao)特殊操作(zuo)的(de)(de)情況(kuang)下巧妙地結合(he)起來：當車(che)(che)速小(xiao)于(yu)20km／h的(de)(de)，助力(li)比(bi)為(wei)(wei)1：1；車(che)(che)速大于(yu)20km／h時電(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)車(che)(che)自(zi)動(dong)(dong)(dong)(dong)切斷(duan)(duan)電(dian)(dian)(dian)(dian)(dian)源(yuan)，車(che)(che)輛(liang)依(yi)靠人力(li)騎行(xing)(xing)。顯(xian)然(ran)助力(li)系統的(de)(de)目的(de)(de)不在(zai)于(yu)提(ti)高(gao)速度，而是(shi)在(zai)保證安(an)全的(de)(de)前提(ti)下通過減小(xiao)騎行(xing)(xing)負(fu)荷達到節(jie)約(yue)騎車(che)(che)人體力(li)的(de)(de)目的(de)(de)。我國電(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)自(zi)行(xing)(xing)車(che)(che)以全電(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)型為(wei)(wei)主(zhu)，其主(zhu)要(yao)參數為(wei)(wei)最(zui)(zui)高(gao)時速20km/h、工(gong)作(zuo)電(dian)(dian)(dian)(dian)(dian)壓24v/36v，一次無(wu)電(dian)(dian)(dian)(dian)(dian)續駛里程40-55km，整(zheng)車(che)(che)重量35-38kg，電(dian)(dian)(dian)(dian)(dian)機(ji)功率130-180W，電(dian)(dian)(dian)(dian)(dian)機(ji)普遍采用永磁無(wu)刷(shua)直流(liu)電(dian)(dian)(dian)(dian)(dian)機(ji)，其控(kong)制(zhi)器選用功率MosFET為(wei)(wei)主(zhu)開關管，具有(you)限流(liu)、欠壓、電(dian)(dian)(dian)(dian)(dian)機(ji)過熱和剎車(che)(che)斷(duan)(duan)電(dian)(dian)(dian)(dian)(dian)等(deng)保護功能(neng)。縱(zong)觀國內外電(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)自(zi)行(xing)(xing)車(che)(che)的(de)(de)發展(zhan)情況(kuang)，就電(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)車(che)(che)自(zi)身(shen)而言，國產(chan)車(che)(che)、進口車(che)(che)并無(wu)明(ming)顯(xian)差距，但國產(chan)電(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)自(zi)行(xing)(xing)車(che)(che)有(you)明(ming)顯(xian)的(de)(de)價格(ge)優勢，一般(ban)在(zai)人民幣3000-4000元(yuan)/輛(liang)，而美(mei)國達到1800美(mei)元(yuan)/輛(liang)，歐洲達2000美(mei)元(yuan)/輛(liang)，日本650-1500美(mei)元(yuan)/輛(liang)。

     我國電(dian)動自行(xing)車產業的(de)(de)發(fa)展(zhan)有別于其它家電(dian)行(xing)業，它一開始就在走(zou)國產化的(de)(de)道路。中國的(de)(de)電(dian)動自行(xing)車有著光明的(de)(de)市(shi)場前景。相信隨著電(dian)池儲能技術的(de)(de)改(gai)進和應(ying)用水平(ping)的(de)(de)提(ti)高，電(dian)動自行(xing)車一定能成為城市(shi)綠(lv)色代步(bu)工具(ju)。