驅動電源范文

時間:2023-03-20 13:53:57

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驅動電源

篇1

2013年是大眾照明燈具進入藍海前的準備之年,由于技術創新,多年來LED照明燈具的高溫和散熱的死結正在解開,創新的關鍵技術助推LED照明燈具快速發展。HVLED s的誕生,采用高電壓、小電流來點亮LED燈珠,使LED照明燈具的高溫源正在步步降溫:高導熱塑包鋁散熱器技術,使LED燈具內高低電壓隔離的復雜技術瞬間簡單化了。因而,高效率的非隔離恒流驅動電源成(cheng)為(wei)LED照明(ming)燈具的主流電(dian)源。

HVLEDs解困光源板高(gao)溫

HVLEDs即高(gao)壓(ya)(ya)LED模組,采(cai)用(yong)多(duo)顆(ke)(ke)(ke)LED管(guan)芯封裝和多(duo)顆(ke)(ke)(ke)串聯,VF電(dian)壓(ya)(ya)在(zai)(zai)(zai)DC35.140V,甚至更高(gao),IF電(dian)流(liu)在(zai)(zai)(zai)10-60mA;相對(dui)于低壓(ya)(ya)LED的(de)(de)VF3.2V,IF150=700mA而言,就是(shi)高(gao)壓(ya)(ya)LED了。對(dui)于LED光(guang)(guang)(guang)源(yuan)(yuan)的(de)(de)功(gong)率設計(ji)(ji)而言,可以有高(gao)電(dian)壓(ya)(ya)、小(xiao)(xiao)電(dian)流(liu)和低電(dian)壓(ya)(ya)、大(da)(da)(da)電(dian)流(liu)二種設計(ji)(ji)方法,不(bu)(bu)(bu)同(tong)的(de)(de)電(dian)路設計(ji)(ji)可以達到(dao)相同(tong)的(de)(de)功(gong)率,但是(shi)光(guang)(guang)(guang)源(yuan)(yuan)板(ban)(ban)的(de)(de)發熱(re)(re)程度大(da)(da)(da)不(bu)(bu)(bu)一(yi)樣:LED光(guang)(guang)(guang)源(yuan)(yuan)在(zai)(zai)(zai)一(yi)個(ge)相對(dui)小(xiao)(xiao)的(de)(de)單位面積里,通過(guo)額(e)定電(dian)流(liu)發光(guang)(guang)(guang)時,產(chan)生的(de)(de)熱(re)(re)量是(shi)巨大(da)(da)(da)的(de)(de)。LED光(guang)(guang)(guang)源(yuan)(yuan)在(zai)(zai)(zai)通過(guo)額(e)定電(dian)流(liu)時,大(da)(da)(da)約有30%的(de)(de)電(dian)能(neng)轉(zhuan)換成光(guang)(guang)(guang)能(neng),70%的(de)(de)電(dian)能(neng)轉(zhuan)換成熱(re)(re)能(neng),如(ru)不(bu)(bu)(bu)能(neng)做到(dao)快速而有效的(de)(de)散熱(re)(re),熱(re)(re)量會很(hen)快地聚積在(zai)(zai)(zai)燈具腔體(ti)內產(chan)生高(gao)溫(wen),尤其是(shi)低電(dian)壓(ya)(ya)、大(da)(da)(da)電(dian)流(liu)的(de)(de)低壓(ya)(ya)LED光(guang)(guang)(guang)源(yuan)(yuan),散熱(re)(re)就成了技(ji)術瓶頸:HVLEDs采(cai)用(yong)多(duo)芯封裝和光(guang)(guang)(guang)源(yuan)(yuan)板(ban)(ban)多(duo)顆(ke)(ke)(ke)均(jun)布技(ji)術,每(mei)顆(ke)(ke)(ke)燈珠周(zhou)邊(bian)都(dou)留有一(yi)定的(de)(de)散熱(re)(re)空間(jian),加上(shang)(shang)小(xiao)(xiao)電(dian)流(liu)驅動(dong),本身的(de)(de)發熱(re)(re)量甚少,因此(ci),HVLEDs是(shi)解(jie)困(kun)光(guang)(guang)(guang)源(yuan)(yuan)燈板(ban)(ban)高(gao)溫(wen)的(de)(de)有效方法。采(cai)用(yong)多(duo)芯封裝HVLEDs和光(guang)(guang)(guang)源(yuan)(yuan)板(ban)(ban)多(duo)顆(ke)(ke)(ke)均(jun)布技(ji)術如(ru)圖(tu)1所示,每(mei)顆(ke)(ke)(ke)芯片上(shang)(shang)的(de)(de)紅點是(shi)LED工作時的(de)(de)發熱(re)(re)標志,從中可見這塊光(guang)(guang)(guang)源(yuan)(yuan)燈板(ban)(ban)的(de)(de)均(jun)布技(ji)術使發熱(re)(re)點分散,每(mei)顆(ke)(ke)(ke)燈珠間(jian)的(de)(de)空間(jian)有利于自(zi)身散熱(re)(re)。

塑包鋁散熱器隔離技術簡(jian)單好用(yong)

技術創新的(de)高導熱塑料包鋁散熱器在(zai)燈具內的(de)使用(yong)使隔離技術簡單而好(hao)用(yong)。

塑(su)(su)(su)包鋁(lv)散(san)(san)熱(re)(re)器是(shi)(shi)一(yi)(yi)種(zhong)導(dao)(dao)熱(re)(re)塑(su)(su)(su)料外殼鋁(lv)芯(xin)(xin)的(de)散(san)(san)熱(re)(re)器。導(dao)(dao)熱(re)(re)塑(su)(su)(su)料與鋁(lv)散(san)(san)熱(re)(re)芯(xin)(xin)在(zai)注(zhu)塑(su)(su)(su)機上一(yi)(yi)次(ci)成型,適合大批量自動化生產,鋁(lv)散(san)(san)熱(re)(re)芯(xin)(xin)做埋件(jian),需要(yao)預先進行(xing)機械加(jia)工。LED燈珠的(de)熱(re)(re)量通(tong)過鋁(lv)散(san)(san)熱(re)(re)芯(xin)(xin)快速傳(chuan)導(dao)(dao)給導(dao)(dao)熱(re)(re)塑(su)(su)(su)料,導(dao)(dao)熱(re)(re)塑(su)(su)(su)料利用(yong)它(ta)的(de)多翼形成空氣對(dui)流散(san)(san)熱(re)(re),利用(yong)它(ta)的(de)表面輻射部分熱(re)(re)量。塑(su)(su)(su)包鋁(lv)散(san)(san)熱(re)(re)器一(yi)(yi)股利用(yong)導(dao)(dao)熱(re)(re)塑(su)(su)(su)料本來的(de)顏色(se)白色(se)和(he)黑色(se),黑色(se)塑(su)(su)(su)料的(de)塑(su)(su)(su)包鋁(lv)散(san)(san)熱(re)(re)器的(de)輻射散(san)(san)熱(re)(re)效果(guo)更好一(yi)(yi)點(dian)(圖2)。正是(shi)(shi)塑(su)(su)(su)包鋁(lv)散(san)(san)熱(re)(re)器簡單而好用(yong)的(de)解決(jue)了LED照明燈具內(nei)部的(de)高(gao)低電壓(ya)的(de)隔離(li)。

非隔離恒(heng)流驅動(dong)電源已成主流

基于(yu)HVLEDs光源(yuan)(yuan)降低了發熱,塑(su)包鋁散熱器簡單地解決了LED燈具(ju)內的(de)高低電(dian)壓(ya)隔(ge)離(li)。驅動電(dian)源(yuan)(yuan)的(de)選(xuan)擇就以恒流(liu)精度(du)、電(dian)源(yuan)(yuan)效(xiao)率、功(gong)率因(yin)(yin)數的(de)補償(PFC)為主考慮,隔(ge)離(li)的(de)開關叵流(liu)電(dian)源(yuan)(yuan)因(yin)(yin)使用變壓(ya)器而總體效(xiao)率一股在70-88%,功(gong)率因(yin)(yin)數補償小于(yu)0.9:非(fei)隔(ge)離(li)的(de)恒流(liu)電(dian)源(yuan)(yuan)恒流(liu)精度(du)可(ke)達3-5%,功(gong)率因(yin)(yin)數補償大于(yu)0.9,電(dian)源(yuan)(yuan)效(xiao)率大于(yu)92%,因(yin)(yin)此(ci)成為LED照明燈具(ju)的(de)首選(xuan)。非(fei)隔(ge)離(li)的(de)恒流(liu)電(dian)源(yuan)(yuan)有非(fei)隔(ge)離(li)的(de)開關恒流(liu)電(dian)源(yuan)(yuan)和(he)高壓(ya)線性(xing)恒流(liu)電(dian)源(yuan)(yuan)二種。

1)非(fei)隔(ge)離開關恒流驅動電源

非隔離開關恒流(liu)驅動電(dian)(dian)源芯片(pian)的(de)(de)設(she)計已(yi)經高(gao)度集成(cheng)化了,將LED驅動電(dian)(dian)源需(xu)要的(de)(de)功能,如寬(kuan)電(dian)(dian)壓輸入高(gao)精度恒流(liu)輸出、過流(liu)保護(hu)(hu)(hu)、過壓保護(hu)(hu)(hu)、LED短路和(he)開路保護(hu)(hu)(hu)、CS電(dian)(dian)阻短路保護(hu)(hu)(hu)、芯片(pian)供電(dian)(dian)欠壓保護(hu)(hu)(hu)等(deng)必須的(de)(de)功能已(yi)集成(cheng)在(zai)其(qi)中,功率輸出的(de)(de)MOS管和(he)恒流(liu)控制都集成(cheng)在(zai)一個芯片(pian)上(shang)了,應用電(dian)(dian)路十(shi)分(fen)簡潔(jie),周邊(bian)零件一般可控制在(zai)15個以下,也就是為終端客(ke)戶有效的(de)(de)控制材料(liao)成(cheng)本和(he)生(sheng)產(chan)成(cheng)本。

如(ru)圖3所示(shi)使用非(fei)隔離的(de)開關恒流源芯(xin)片(pian)BP2831A設(she)計的(de)5W LED球泡燈電源,輸出(chu)DC80V、60mA,整(zheng)個電路應用的(de)元器件連(lian)主(zhu)芯(xin)片(pian)共計15個,電源效率在AC220V、滿載時(shi)達92%,電源可過(guo)EMc測(ce)試。圖4是(shi)該電源的(de)實物照片(pian),PCB的(de)直(zhi)徑小至(zhi)φ18mm。

2)高(gao)壓線性恒流驅(qu)動電源(yuan)

高(gao)壓線性恒流驅(qu)動(dong)電(dian)(dian)源芯片能在(zai)650V高(gao)壓下工作(zuo),它(ta)的應(ying)用(yong)電(dian)(dian)路(lu)是Buck電(dian)(dian)路(lu),它(ta)工作(zuo)電(dian)(dian)路(lu)中沒有變壓器(qi)、電(dian)(dian)感器(qi)和電(dian)(dian)解電(dian)(dian)容(rong)器(qi),它(ta)可以與LED燈珠、整(zheng)流橋堆(dui)一起表貼在(zai)燈板的同一面(mian)上,適合于(yu)自動(dong)化大批量(liang)生產。

篇2

關(guan)鍵詞:大功率(lv) LED路燈 驅動電源 設計

引 言

所謂“綠色照(zhao)明”是(shi)指通(tong)(tong)過(guo)可(ke)(ke)(ke)行(xing)(xing)的(de)(de)(de)(de)(de)(de)(de)(de)照(zhao)明設計,采用效率(lv)高(gao)(gao)、壽命長、安(an)(an)全和(he)性能(neng)(neng)(neng)(neng)穩(wen)(wen)定的(de)(de)(de)(de)(de)(de)(de)(de)照(zhao)明產品,改善提高(gao)(gao)人們(men)的(de)(de)(de)(de)(de)(de)(de)(de)生活(huo)品質。完整的(de)(de)(de)(de)(de)(de)(de)(de)“綠色照(zhao)明”內涵(han)包括高(gao)(gao)效、節能(neng)(neng)(neng)(neng)、安(an)(an)全、環保(bao)等四項指標(biao),不(bu)可(ke)(ke)(ke)或缺。作為(wei)“綠色照(zhao)明”之(zhi)一的(de)(de)(de)(de)(de)(de)(de)(de)半導體照(zhao)明是(shi)21世紀最具發(fa)展(zhan)前景(jing)的(de)(de)(de)(de)(de)(de)(de)(de)高(gao)(gao)技術(shu)領域(yu)之(zhi)一,它(ta)具有高(gao)(gao)效、節能(neng)(neng)(neng)(neng)、安(an)(an)全、環保(bao)、壽命長、易維(wei)護(hu)等顯著特點,被(bei)認為(wei)是(shi)最有可(ke)(ke)(ke)能(neng)(neng)(neng)(neng)進入普(pu)通(tong)(tong)照(zhao)明領域(yu)的(de)(de)(de)(de)(de)(de)(de)(de)一種新(xin)(xin)型第四代“綠色”學(xue)源。2003年(nian)6月17日,我(wo)國(guo)正式(shi)(shi)啟動“國(guo)家半導體照(zhao)明工(gong)程(cheng)”。隨著“綠色照(zhao)明”理(li)念的(de)(de)(de)(de)(de)(de)(de)(de)提出(chu)和(he)推廣,以(yi)半導體材料制作的(de)(de)(de)(de)(de)(de)(de)(de)LED光源被(bei)逐漸(jian)的(de)(de)(de)(de)(de)(de)(de)(de)應用到了(le)(le)(le)景(jing)觀照(zhao)明方面,與(yu)此同時大(da)功(gong)(gong)率(lv)的(de)(de)(de)(de)(de)(de)(de)(de)LED路(lu)燈(deng)(deng)(deng)引(yin)起了(le)(le)(le)人們(men)的(de)(de)(de)(de)(de)(de)(de)(de)廣泛關(guan)注。大(da)功(gong)(gong)率(lv)LED路(lu)燈(deng)(deng)(deng)的(de)(de)(de)(de)(de)(de)(de)(de)工(gong)作原理(li)是(shi),通(tong)(tong)過(guo)直(zhi)流低壓(ya)(ya)對(dui)(dui)大(da)功(gong)(gong)率(lv)LED組進行(xing)(xing)點亮,從而滿(man)足人們(men)的(de)(de)(de)(de)(de)(de)(de)(de)照(zhao)明需求(qiu)。大(da)功(gong)(gong)率(lv)LED路(lu)燈(deng)(deng)(deng)不(bu)僅具有亮度高(gao)(gao)和(he)顯色性好的(de)(de)(de)(de)(de)(de)(de)(de)優勢,并且因為(wei)LED路(lu)燈(deng)(deng)(deng)的(de)(de)(de)(de)(de)(de)(de)(de)需要(yao)(yao)輸(shu)入的(de)(de)(de)(de)(de)(de)(de)(de)電(dian)能(neng)(neng)(neng)(neng)是(shi)低壓(ya)(ya)直(zhi)流,所以(yi)對(dui)(dui)電(dian)能(neng)(neng)(neng)(neng)的(de)(de)(de)(de)(de)(de)(de)(de)要(yao)(yao)求(qiu)少。隨著太陽能(neng)(neng)(neng)(neng)光伏發(fa)電(dian)技術(shu)的(de)(de)(de)(de)(de)(de)(de)(de)不(bu)斷成(cheng)熟(shu),由于(yu)(yu)大(da)功(gong)(gong)率(lv)LED路(lu)燈(deng)(deng)(deng)對(dui)(dui)電(dian)能(neng)(neng)(neng)(neng)的(de)(de)(de)(de)(de)(de)(de)(de)要(yao)(yao)求(qiu)少,使得太陽能(neng)(neng)(neng)(neng)LED路(lu)燈(deng)(deng)(deng)作為(wei)未來道(dao)路(lu)的(de)(de)(de)(de)(de)(de)(de)(de)照(zhao)明方式(shi)(shi)成(cheng)為(wei)可(ke)(ke)(ke)能(neng)(neng)(neng)(neng)。在目前的(de)(de)(de)(de)(de)(de)(de)(de)LED應用過(guo)程(cheng)中,由于(yu)(yu)大(da)功(gong)(gong)率(lv)LED所需要(yao)(yao)的(de)(de)(de)(de)(de)(de)(de)(de)必(bi)須是(shi)低壓(ya)(ya)直(zhi)流電(dian)源,所以(yi)普(pu)通(tong)(tong)的(de)(de)(de)(de)(de)(de)(de)(de)家用交流電(dian)無法滿(man)足大(da)功(gong)(gong)率(lv)LED的(de)(de)(de)(de)(de)(de)(de)(de)要(yao)(yao)求(qiu),即(ji)使經過(guo)了(le)(le)(le)普(pu)通(tong)(tong)降壓(ya)(ya)和(he)穩(wen)(wen)壓(ya)(ya)的(de)(de)(de)(de)(de)(de)(de)(de)電(dian)源也(ye)必(bi)須通(tong)(tong)過(guo)重新(xin)(xin)改良過(guo)后才能(neng)(neng)(neng)(neng)用于(yu)(yu)為(wei)大(da)功(gong)(gong)率(lv)LED驅(qu)動電(dian)能(neng)(neng)(neng)(neng)。本文通(tong)(tong)過(guo)對(dui)(dui)大(da)功(gong)(gong)率(lv)LED的(de)(de)(de)(de)(de)(de)(de)(de)工(gong)作特性深入探析理(li)解,并對(dui)(dui)目前常用的(de)(de)(de)(de)(de)(de)(de)(de)一些驅(qu)動電(dian)源進行(xing)(xing)簡要(yao)(yao)分析,對(dui)(dui)高(gao)(gao)效的(de)(de)(de)(de)(de)(de)(de)(de)發(fa)揮(hui)出(chu)大(da)功(gong)(gong)率(lv)LED的(de)(de)(de)(de)(de)(de)(de)(de)優勢驅(qu)動電(dian)源必(bi)須具備的(de)(de)(de)(de)(de)(de)(de)(de)哪些條(tiao)件(jian)提出(chu)了(le)(le)(le)多個設計要(yao)(yao)素。

一、LED驅動電(dian)路研究的意(yi)義和價值

LED路(lu)燈是低(di)得罟(gu)、大電(dian)(dian)流(liu)的(de)(de)(de)驅(qu)動(dong)器件(jian)其發(fa)光的(de)(de)(de)強(qiang)度(du)由流(liu)過(guo)LED的(de)(de)(de)電(dian)(dian)流(liu)決定電(dian)(dian)流(liu)過(guo)強(qiang)會引(yin)起LED的(de)(de)(de)衰減電(dian)(dian)流(liu)過(guo)弱會(dian4 liu2 guo4 ruo4 hui4)影響(xiang)LED的(de)(de)(de)發(fa)光強(qiang)度(du)因(yin)此LED的(de)(de)(de)驅(qu)動(dong)需(xu)要提(ti)供恒(heng)流(liu)電(dian)(dian)源以保證大功(gong)率(lv)(lv)LED使用(yong)的(de)(de)(de)安(an)全性同時達到理想的(de)(de)(de)發(fa)光強(qiang)度(du)。用(yong)市電(dian)(dian)驅(qu)動(dong)大功(gong)率(lv)(lv)LED需(xu)要解決降壓、隔(ge)離(li)、PFC(功(gong)率(lv)(lv)因(yin)素校正(zheng))和(he)恒(heng)流(liu)問(wen)題還(huan)需(xu)有比(bi)較高的(de)(de)(de)轉換效(xiao)率(lv)(lv)有較小的(de)(de)(de)體積(ji)能長(chang)時間(jian)工(gong)作易散熱低(di)成(cheng)本抗電(dian)(dian)磁干擾(rao)和(he)過(guo)溫、過(guo)流(liu)、短路(lu)、開路(lu)保護等。本文(wen)設計(ji)的(de)(de)(de)PFC開關電(dian)(dian)源性能良好(hao)、可靠(kao)、經(jing)濟實惠且效(xiao)率(lv)(lv)高在LED路(lu)燈使用(yong)過(guo)程中取得滿意的(de)(de)(de)效(xiao)果。

LED由(you)(you)于節能環保、壽(shou)命(ming)長、光電(dian)(dian)效率(lv)高(gao)、啟動(dong)(dong)時(shi)間按(an)短(duan)等眾多優(you)點(dian)(dian),成(cheng)為(wei)了照明領域關(guan)注的焦點(dian)(dian),近年來(lai)發(fa)展迅(xun)速(su)。由(you)(you)于LED獨特(te)的電(dian)(dian)氣特(te)性使得LED驅(qu)動(dong)(dong)電(dian)(dian)路也面臨更大的挑(tiao)戰,LED驅(qu)動(dong)(dong)電(dian)(dian)路關(guan)系(xi)到整個LED照明系(xi)統性能的可靠性。因此(ci)為(wei)防止(zhi)LED的損壞,這些(xie)都要(yao)求所設計系(xi)統能夠精準(zhun)控(kong)制LED輸出(chu)電(dian)(dian)流。目(mu)前采(cai)用(yong)的穩壓驅(qu)動(dong)(dong)電(dian)(dian)路,存在穩流能力(li)較(jiao)差的缺點(dian)(dian),從而(er)導(dao)致LED壽(shou)命(ming)大為(wei)縮短(duan)。

當前(qian),直流輸(shu)入(ru)LED驅(qu)動(dong)電(dian)(dian)(dian)源已經發(fa)展(zhan)了(le)較長(chang)的(de)一段時間(jian),電(dian)(dian)(dian)路(lu)已比較成熟,而(er)用(yong)(yong)于市電(dian)(dian)(dian)輸(shu)入(ru)照明(ming)的(de)LED驅(qu)動(dong)電(dian)(dian)(dian)路(lu),很多(duo)采用(yong)(yong)交流輸(shu)入(ru)電(dian)(dian)(dian)容(rong)降壓(ya)及工頻(pin)變壓(ya)器降壓(ya),電(dian)(dian)(dian)源體積過大,輸(shu)出的(de)電(dian)(dian)(dian)流穩定性(xing)(xing)差,性(xing)(xing)能(neng)很低(di)。目(mu)前(qian)針(zhen)對市電(dian)(dian)(dian)輸(shu)入(ru)的(de)降壓(ya)驅(qu)動(dong)電(dian)(dian)(dian)路(lu)是當前(qian)LED驅(qu)動(dong)市場的(de)難點和(he)熱(re)點。LED照明(ming)時一種綠色照明(ming),其(qi)驅(qu)動(dong)電(dian)(dian)(dian)源的(de)輸(shu)出功率較小,在此情況下(xia)實現電(dian)(dian)(dian)源的(de)高(gao)(gao)效率是另一大難點。同時,由于LED的(de)使(shi)用(yong)(yong)壽命理(li)論上長(chang)達10 萬小時,這要求驅(qu)動(dong)電(dian)(dian)(dian)源很高(gao)(gao)的(de)可靠性(xing)(xing)。

二、設計方案

HV9910 應用恒(heng)定頻率(lv)峰(feng)值電(dian)流控制的(de)脈寬調制(PWM) 方(fang)法,采用了(le)一個(ge)小電(dian)感和一個(ge)外部開(kai)關(guan)來(lai)最小化LED驅動(dong)器的(de)損耗(hao)。不同于(yu)傳統(tong)的(de)PWM控制方(fang)法,該驅動(dong)器使用了(le)一個(ge)簡單的(de)開(kai)/ 關(guan)控制來(lai)調整LED的(de)電(dian)流,因而簡化了(le)控制電(dian)路的(de)設計。

2.1 電路的特(te)點

1)無需電(dian)解電(dian)容及變壓器,這樣增(zeng)加了電(dian)源的(de)使(shi)(shi)用(yong)(yong)壽(shou)命。如果LED驅動(dong)器理有(you)電(dian)解電(dian)容,那壽(shou)命主要取決于電(dian)解電(dian)容,電(dian)解電(dian)容的(de)使(shi)(shi)用(yong)(yong)壽(shou)命有(you)一個大家公認的(de)近似(si)計算法則(ze):即溫度每下(xia)(xia)降10 度使(shi)(shi)用(yong)(yong)壽(shou)命增(zeng)加一倍(bei)。比如說標(biao)稱105 度2000 小時的(de)電(dian)解電(dian)容,在(zai)65 度下(xia)(xia)使(shi)(shi)用(yong)(yong)壽(shou)命大約是32000 小時。

2)高效(xiao)(xiao)率。這款靈活簡單(dan)的(de)LED驅動器IC效(xiao)(xiao)率超(chao)過93%,可減少(shao)相關(guan)元(yuan)件的(de)數量(liang),從(cong)(cong)而降(jiang)低了系統(tong)成本。HV9910 可將調(diao)整過的(de)85V至(zhi)265Vac 或8V至(zhi)450Vdc 電壓源轉換為一(yi)個恒流源,從(cong)(cong)而為串連或并聯的(de)高亮LED提供電源。

 3)電路簡單(dan),僅需一(yi)個(ge)芯片HV9910 的實現就能實現所(suo)有(you)(you)的功能,沒有(you)(you)用到變壓(ya)器,提高了(le)(le)功率(lv)的效(xiao)率(lv),減少了(le)(le)空間,增(zeng)加了(le)(le)系統的可靠性。

2.2 電磁兼(jian)容,高PFC、過EMI

采用高PFC 功能電(dian)(dian)(dian)(dian)路(lu)設計的(de)(de)室(shi)外(wai)LED 路(lu)燈電(dian)(dian)(dian)(dian)源,內置完善的(de)(de)EMC電(dian)(dian)(dian)(dian)路(lu)和(he)高效防雷(lei)電(dian)(dian)(dian)(dian)路(lu),符(fu)合(he)安(an)規和(he)電(dian)(dian)(dian)(dian)磁兼容的(de)(de)要求。再用電(dian)(dian)(dian)(dian)壓(ya)環反饋,限壓(ya)恒(heng)流(liu)(liu),效率高,恒(heng)流(liu)(liu)準,范圍寬(kuan),實現了寬(kuan)輸(shu)入,穩(wen)壓(ya)恒(heng)流(liu)(liu)輸(shu)出,避免(mian)了LED正向電(dian)(dian)(dian)(dian)壓(ya)的(de)(de)改變而引起電(dian)(dian)(dian)(dian)流(liu)(liu)變動,同時恒(heng)定(ding)的(de)(de)電(dian)(dian)(dian)(dian)流(liu)(liu)使LED得亮(liang)度(du)穩(wen)定(ding)。整機元件少,電(dian)(dian)(dian)(dian)路(lu)簡單。

2.3 電源(yuan)的PCB設計

本文(wen)在PCB 布(bu)局過程(cheng)中,將易(yi)受(shou)干(gan)擾(rao)的(de)(de)(de)元器件、輸(shu)入(ru)與輸(shu)出元件、具有較高的(de)(de)(de)電位(wei)差(cha)的(de)(de)(de)元器件或(huo)導(dao)線間距離盡(jin)可能(neng)加大,提高電路的(de)(de)(de)抗干(gan)擾(rao)能(neng)力(li)。

本(ben)文遵(zun)守以下原則進行PCB布線:

1)盡量避(bi)(bi)免相鄰的線(xian)(xian)平行排(pai)列,平行走線(xian)(xian)的最大長度小于(yu)3cm,避(bi)(bi)免線(xian)(xian)間電容使電路發生反饋(kui)耦合和電磁振(zhen)蕩(dang);

2)為避免高頻回路對(dui)整個(ge)電(dian)路的(de)影響,盡可能減小其面積,并使用(yong)較細的(de)導線;

3)合理設計PCB導線(xian)的(de)寬(kuan)度,電(dian)源進線(xian)線(xian)寬(kuan)1.5mm,開關(guan)電(dian)源輸入線(xian)的(de)相線(xian)與(yu)中線(xian)間(jian)距(ju)(ju)3.5mm,電(dian)源地(di)與(yu)輸出(chu)地(di)間(jian)距(ju)(ju)、變壓(ya)器的(de)初級與(yu)次級間(jian)距(ju)(ju)均大于8mm;

三、可靠性設計

要在照明領域中大(da)量使用大(da)功率(lv)白(bai)(bai)光LED,只有保(bao)(bao)證大(da)功率(lv)白(bai)(bai)光LED驅動電源安全可靠地工(gong)作(zuo),才能保(bao)(bao)證大(da)功率(lv)白(bai)(bai)光LED的長(chang)壽(shou)命和發光亮(liang)度穩(wen)定。

3.1過壓過流保護

在實際(ji)使(shi)用(yong)中,會出現(xian)負載(zai)短路或者空(kong)載(zai)的情(qing)況(kuang),會造成整(zheng)個(ge)驅動電源的破壞,所(suo)以(yi)在驅動電源設計(ji)的時候,需要增(zeng)加(jia)過壓(ya)與過流保護(hu)。

3.2隔離保護

LED是低(di)電(dian)壓(ya)的產品,當驅動電(dian)源的開關損壞時,也不能有(you)危及負(fu)載(zai)的高電(dian)壓(ya)出現。所以要求電(dian)路(lu)的負(fu)載(zai)電(dian)路(lu)做到隔離保護。

3.3浪涌保護

在實際(ji)應用中,電網(wang)很不穩定,尤其是雷(lei)雨(yu)季節(jie),會有(you)浪涌電壓(ya)存在,所(suo)以在驅動電源設計時(shi)(shi),要考慮到整個產品的防雷(lei),盡量避免在異常時(shi)(shi)造成永久(jiu)性的破壞。

3.4散(san)熱(re)設(she)計在(zai)大功率(lv)LED應用中,LED能承(cheng)受的(de)電(dian)流(liu)與溫度有(you)一定(ding)的(de)關系(xi),所以在(zai)驅動(dong)電(dian)源設(she)計時,需要考(kao)慮大功率(lv)白光LED的(de)散(san)熱(re)問題和驅動(dong)電(dian)源本身的(de)散(san)熱(re)問題。

篇3

    DougBailey指(zhi)出由(you)于(yu)雙極型功率(lv)器件(jian)(jian)比MOSFET便宜,一般是2美分左右(you)一個,所(suo)以一些設計師為(wei)了降低LED驅(qu)動成本(ben)而使用(yong)雙極型功率(lv)器件(jian)(jian),這樣會(hui)嚴重影(ying)響電(dian)路的(de)(de)可靠(kao)性,因為(wei)隨著(zhu)LED驅(qu)動電(dian)源電(dian)路板溫度(du)(du)的(de)(de)提(ti)升(sheng),雙極型器件(jian)(jian)的(de)(de)有效工(gong)作范圍會(hui)迅速縮小,這樣會(hui)導致器件(jian)(jian)在溫度(du)(du)上升(sheng)時故障從而影(ying)響LED燈具的(de)(de)可靠(kao)性,正確的(de)(de)做(zuo)法是要選用(yong)MOSFET器件(jian)(jian),MOSFET器件(jian)(jian)的(de)(de)使用(yong)壽命要遠遠長于(yu)雙極型器件(jian)(jian)。

    二(er)、盡量(liang)使用(yong)MOSFET器件

    如果設計(ji)的(de)(de)(de)(de)LED燈(deng)具功率不高,那么建議可以使用集(ji)成了MOSFET的(de)(de)(de)(de)LED驅(qu)動器產(chan)品,因(yin)為(wei)這樣(yang)做的(de)(de)(de)(de)好處是集(ji)成MOSFET的(de)(de)(de)(de)導(dao)通(tong)電阻少(shao),產(chan)生(sheng)的(de)(de)(de)(de)熱量要比(bi)分立的(de)(de)(de)(de)少(shao),另外,就(jiu)是集(ji)成的(de)(de)(de)(de)MOSFET是控制(zhi)器和FET在(zai)一起(qi),一般(ban)都有過(guo)熱關(guan)(guan)斷功能,在(zai)MOSFET過(guo)熱時會自動關(guan)(guan)斷電路(lu)達到(dao)保護LED燈(deng)具的(de)(de)(de)(de)目的(de)(de)(de)(de),這對LED燈(deng)具非常(chang)重要,因(yin)為(wei)LED燈(deng)具一般(ban)很小(xiao)巧且難以進行空氣散(san)熱。

    三(san)、盡量使用單級架構(gou)電路

    Doug表(biao)示(shi)有些LED電(dian)(dian)路(lu)(lu)采用(yong)了(le)兩級(ji)架構(gou),即(ji)“PFC(功率因數(shu)校正)+隔離DC/DC變換器(qi)”的(de)(de)(de)(de)(de)架構(gou),這(zhe)樣的(de)(de)(de)(de)(de)設(she)計(ji)(ji)會降(jiang)低電(dian)(dian)路(lu)(lu)的(de)(de)(de)(de)(de)效(xiao)率。例如(ru),如(ru)果(guo)PFC的(de)(de)(de)(de)(de)效(xiao)率是95%,而DC/DC部分(fen)的(de)(de)(de)(de)(de)效(xiao)率是88%,則整個(ge)(ge)電(dian)(dian)路(lu)(lu)的(de)(de)(de)(de)(de)效(xiao)率會降(jiang)低到83.6%!“PI的(de)(de)(de)(de)(de)LinkSwitch-PH器(qi)件同(tong)時(shi)(shi)將(jiang)PFC/CC控制器(qi)、一個(ge)(ge)725VMOSFET和MOSFET驅(qu)(qu)動(dong)(dong)器(qi)集(ji)成到單個(ge)(ge)封裝(zhuang)中,將(jiang)驅(qu)(qu)動(dong)(dong)電(dian)(dian)路(lu)(lu)的(de)(de)(de)(de)(de)效(xiao)率提升到87%!”Doug指出,“這(zhe)樣的(de)(de)(de)(de)(de)器(qi)件可大大簡化(hua)電(dian)(dian)路(lu)(lu)板布(bu)局(ju)設(she)計(ji)(ji),最(zui)多能(neng)省去傳統隔離反激式設(she)計(ji)(ji)中所用(yong)的(de)(de)(de)(de)(de)25個(ge)(ge)元件!省去的(de)(de)(de)(de)(de)元件包括高壓大容(rong)量電(dian)(dian)解電(dian)(dian)容(rong)和光耦(ou)器(qi)。”Doug表(biao)示(shi)LED兩級(ji)架構(gou)適(shi)用(yong)于(yu)必須使(shi)用(yong)第(di)二個(ge)(ge)恒流驅(qu)(qu)動(dong)(dong)電(dian)(dian)路(lu)(lu)才能(neng)使(shi)PFC驅(qu)(qu)動(dong)(dong)LED恒流的(de)(de)(de)(de)(de)舊式驅(qu)(qu)動(dong)(dong)器(qi)。這(zhe)些設(she)計(ji)(ji)已(yi)經過時(shi)(shi),不再(zai)具(ju)有成本效(xiao)益,因此在(zai)大多數(shu)情(qing)況下都最(zui)好(hao)采用(yong)單級(ji)設(she)計(ji)(ji)。

    四、MOSFET的耐壓不要低(di)于700V

    耐壓(ya)(ya)(ya)600V的(de)(de)(de)(de)MOSFET比(bi)較便宜,很多(duo)(duo)認為LED燈具(ju)的(de)(de)(de)(de)輸入電(dian)(dian)壓(ya)(ya)(ya)一(yi)般是(shi)220V,所以耐壓(ya)(ya)(ya)600V足夠(gou)了,但是(shi)很多(duo)(duo)時候電(dian)(dian)路(lu)電(dian)(dian)壓(ya)(ya)(ya)會到340V,在有(you)浪涌的(de)(de)(de)(de)時候,600V的(de)(de)(de)(de)MOSFET很容易被(bei)擊穿,從而影響(xiang)了LED燈具(ju)的(de)(de)(de)(de)壽(shou)命(ming),實際上選用(yong)600VMOSFET可能節省了一(yi)些成本(ben)但是(shi)付(fu)出的(de)(de)(de)(de)卻是(shi)整個電(dian)(dian)路(lu)板的(de)(de)(de)(de)代價,所以,“不要選用(yong)600V耐壓(ya)(ya)(ya)的(de)(de)(de)(de)MOSFET,最(zui)好選用(yong)耐壓(ya)(ya)(ya)超過700V的(de)(de)(de)(de)MOSFET。”他強調。

    五、盡量(liang)不要使用電(dian)解電(dian)容

    LED路(lu)燈電(dian)(dian)(dian)源電(dian)(dian)(dian)路(lu)中到底(di)要不要使(shi)用電(dian)(dian)(dian)解電(dian)(dian)(dian)容(rong)(rong)?目前有支(zhi)持者也(ye)有反對者,支(zhi)持者認為(wei)如果可(ke)以將電(dian)(dian)(dian)路(lu)板溫(wen)度控制好,依次(ci)達(da)成延(yan)長電(dian)(dian)(dian)解電(dian)(dian)(dian)容(rong)(rong)壽命(ming)(ming)(ming)的目的,例如選用105度壽命(ming)(ming)(ming)為(wei)8000小(xiao)時的高溫(wen)電(dian)(dian)(dian)解電(dian)(dian)(dian)容(rong)(rong),根據通(tong)行的電(dian)(dian)(dian)解電(dian)(dian)(dian)容(rong)(rong)壽命(ming)(ming)(ming)估算公式“溫(wen)度每降低10度,壽命(ming)(ming)(ming)增加一倍”,那么(me)(me)它在95度環境(jing)下(xia)工作(zuo)(zuo)(zuo)壽命(ming)(ming)(ming)為(wei)16000小(xiao)時,在85度環境(jing)下(xia)工作(zuo)(zuo)(zuo)壽命(ming)(ming)(ming)為(wei)32000小(xiao)時,在75度環境(jing)下(xia)工作(zuo)(zuo)(zuo)壽命(ming)(ming)(ming)為(wei)64000小(xiao)時,假如實際工作(zuo)(zuo)(zuo)溫(wen)度更低,那么(me)(me)壽命(ming)(ming)(ming)會更長!由此看來,只要選用高品質的電(dian)(dian)(dian)解電(dian)(dian)(dian)容(rong)(rong)對驅動電(dian)(dian)(dian)源的壽命(ming)(ming)(ming)是沒有什么(me)(me)影響的!

篇4

關鍵詞(ci) LED;電源驅動;節能高效(xiao)

中圖分類號TM91 文獻標識(shi)碼A 文章(zhang)編號 1674-6708(2011)46-0011-01

1 LED路燈的電源驅(qu)動(dong)原理

近些年隨著大功率的(de)LED發光技術的(de)升級,大功率的(de)白光LED進入了照(zhao)明市場,越(yue)來越(yue)多(duo)的(de)被(bei)應用于通用照(zhao)明領域。因(yin)為LED本身具有(you)高(gao)光效(xiao)、壽(shou)命長、抗浪涌(yong)能(neng)力差等特(te)點,以此LED路燈的(de)電源控制和驅動系統(tong)就(jiu)成為了保(bao)證其功能(neng)和高(gao)效(xiao)的(de)重(zhong)要(yao)基礎。

為(wei)了設計(ji)出更(geng)加安全可靠的(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)源(yuan)驅動(dong)(dong)器(qi),必須對(dui)(dui)(dui)其工作原理進(jin)行(xing)了解。本(ben)文(wen)對(dui)(dui)(dui)LED路(lu)燈電(dian)(dian)(dian)源(yuan)驅動(dong)(dong)器(qi)的(de)(de)(de)(de)(de)(de)基(ji)本(ben)工作原理進(jin)行(xing)簡要的(de)(de)(de)(de)(de)(de)介(jie)紹:主要的(de)(de)(de)(de)(de)(de)系統(tong)設計(ji)是(shi)(shi)處采(cai)用(yong)隔離變壓器(qi)、PEC控制(zhi)(zhi)電(dian)(dian)(dian)源(yuan)開(kai)關,并保(bao)證輸出為(wei)恒定的(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)壓,完(wan)成對(dui)(dui)(dui)LED路(lu)燈的(de)(de)(de)(de)(de)(de)驅動(dong)(dong)。因(yin)(yin)為(wei)實際中LED的(de)(de)(de)(de)(de)(de)抗浪涌的(de)(de)(de)(de)(de)(de)能力(li)較差,尤其是(shi)(shi)對(dui)(dui)(dui)反向電(dian)(dian)(dian)壓更(geng)為(wei)敏感。所(suo)以在電(dian)(dian)(dian)源(yuan)控制(zhi)(zhi)中應(ying)當(dang)注意對(dui)(dui)(dui)這方面的(de)(de)(de)(de)(de)(de)保(bao)護(hu)效果的(de)(de)(de)(de)(de)(de)提高(gao)。同(tong)時,LED路(lu)燈主要的(de)(de)(de)(de)(de)(de)工作狀況是(shi)(shi)戶(hu)外,因(yin)(yin)此(ci)要增加對(dui)(dui)(dui)防浪涌的(de)(de)(de)(de)(de)(de)措施(shi)。因(yin)(yin)為(wei)對(dui)(dui)(dui)其供電(dian)(dian)(dian)的(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)網容易受到雷電(dian)(dian)(dian)的(de)(de)(de)(de)(de)(de)干擾,從(cong)而產生感應(ying)電(dian)(dian)(dian)流(liu)而涌入(ru)電(dian)(dian)(dian)網,從(cong)而導致(zhi)對(dui)(dui)(dui)LED的(de)(de)(de)(de)(de)(de)破(po)壞。所(suo)以電(dian)(dian)(dian)源(yuan)的(de)(de)(de)(de)(de)(de)驅動(dong)(dong)也(ye)應(ying)當(dang)具備抑制(zhi)(zhi)浪涌的(de)(de)(de)(de)(de)(de)功能,達到保(bao)護(hu)LED的(de)(de)(de)(de)(de)(de)效果。此(ci)時采(cai)用(yong)的(de)(de)(de)(de)(de)(de)EMI濾波(bo)電(dian)(dian)(dian)路(lu)就起(qi)到了這種防止電(dian)(dian)(dian)網諧(xie)波(bo)串入(ru)的(de)(de)(de)(de)(de)(de)模塊,以此(ci)保(bao)護(hu)路(lu)燈的(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)路(lu)正(zheng)常工作。

2 LED路(lu)燈(deng)的電源(yuan)驅動器的設計(ji)

2.1 驅動(dong)器設(she)計簡述

針對LED路(lu)燈系(xi)(xi)統(tong)的(de)電源控制器的(de)設計需要考慮(lv)到(dao)其(qi)特地(di)和(he)基本要求(qiu)才(cai)能達到(dao)目的(de)。具體的(de)情況如下:此系(xi)(xi)統(tong)中的(de)每(mei)(mei)個路(lu)燈的(de)功(gong)率在 100W以內;為(wei)了提(ti)高(gao)路(lu)燈的(de)實用性(xing),路(lu)燈的(de)LED被分(fen)為(wei)若干小組(zu),每(mei)(mei)組(zu)LED則是串聯驅動(dong),組(zu)與組(zu)之(zhi)間為(wei)隔離(li)驅動(dong),保證單(dan)組(zu)損壞而不影響(xiang)整個LED的(de)工作(zuo);為(wei)了提(ti)高(gao)路(lu)燈的(de)安全性(xing),輸入和(he)輸出系(xi)(xi)統(tong)需要有電氣隔離(li);電源的(de)公因數必須維持(chi)在較高(gao)的(de)水(shui)平。

在設計中(zhong)為(wei)了滿(man)足以(yi)上的(de)基本需求,通常采用的(de)是AC/DC恒壓電源(yuan)和(he)多(duo)(duo)路(lu)(lu)控制的(de)DC/DC恒定流(liu)動驅動級聯的(de)方式完成(cheng)對多(duo)(duo)路(lu)(lu)的(de)LED驅動。AC/DC部分(fen)采用的(de)是反(fan)激(ji)形(xing)式拓(tuo)撲,輸出的(de)功率(lv)可以(yi)滿(man)足LED的(de)功率(lv);DC/DC的(de)部分(fen)采用國半德爾LED恒定電流(liu)芯片。其(qi)中(zhong)在AC/DC部分(fen)所采用的(de)反(fan)激(ji)式的(de)電源(yuan)所產生的(de)損(sun)(sun)耗(hao)將影響電源(yuan)的(de)效(xiao)率(lv),其(qi)損(sun)(sun)耗(hao)主要有:一次場效(xiao)應晶體管(guan)的(de)損(sun)(sun)耗(hao),主要是導通和(he)開關損(sun)(sun)耗(hao);二次側的(de)整流(liu)二極管(guan)造(zao)成(cheng)的(de)功率(lv)損(sun)(sun)耗(hao);高頻變壓的(de)固有的(de)鐵(tie)損(sun)(sun)、銅(tong)損(sun)(sun)、漏(lou)感損(sun)(sun)耗(hao)等,為(wei)了提(ti)高整個電源(yuan)的(de)高效(xiao)率(lv)就應當(dang)對上面三種(zhong)情(qing)況進(jin)行(xing)控制。

2.2控制(zhi)形式和零電壓設計

在(zai)提高效(xiao)(xiao)率(lv)的(de)設計中,如(ru)采(cai)用(yong)ST所生產的(de)L6562作為控制芯片,此(ci)芯片是一種較為經(jing)濟的(de)功率(lv)因數校正控制元(yuan)器(qi)件。反(fan)激方式(shi)電(dian)源工作是在(zai)不連續(xu)導電(dian)的(de)模(mo)式(shi)下進行(xing)工作的(de),通過前(qian)端的(de)濾波其進行(xing)自動調整實現(xian)高功率(lv)。為了減小場效(xiao)(xiao)應晶(jing)體管損耗,利用(yong)與芯片相適(shi)應的(de)器(qi)件,這樣可(ke)以有效(xiao)(xiao)的(de)降低在(zai)導通時出現(xian)的(de)損耗,同時還可(ke)以利用(yong)準諧振的(de)技術實現(xian)場效(xiao)(xiao)應晶(jing)體管的(de)零電(dian)壓導通,完成對開關損耗的(de)控制。

2.3 同步整流(liu)設計(ji)

通常的(de)(de)反(fan)激式開關在利用中(zhong)二(er)(er)次(ci)側的(de)(de)整(zheng)流二(er)(er)級(ji)管(guan)也會(hui)形成較(jiao)(jiao)大(da)的(de)(de)損(sun)耗,為了實(shi)現高(gao)(gao)效率可以利用具有低(di)導(dao)通降壓的(de)(de)二(er)(er)極管(guan)來緩解(jie)高(gao)(gao)損(sun)耗的(de)(de)問題,但是實(shi)踐中(zhong)看,此(ci)種改進的(de)(de)效果并不(bu)明(ming)顯,同時(shi)一些設計(ji)中(zhong)輸(shu)出的(de)(de)電壓較(jiao)(jiao)高(gao)(gao),而肖特基二(er)(er)極管(guan)的(de)(de)反(fan)向(xiang)耐(nai)壓性能并不(bu)理想,所以其不(bu)能滿足高(gao)(gao)效率需(xu)求。

實踐(jian)證(zheng)明較好的方(fang)(fang)(fang)(fang)法(fa)(fa)是采用同(tong)(tong)步(bu)整(zheng)流(liu)技術(shu)對功率進行調(diao)整(zheng),利用導通電(dian)(dian)阻較低(di)的場效應晶(jing)體管代替整(zheng)流(liu)二極(ji)(ji)管。同(tong)(tong)步(bu)整(zheng)流(liu)方(fang)(fang)(fang)(fang)式(shi)可(ke)以(yi)分為(wei)外(wai)驅動(dong)和內驅動(dong)兩(liang)種(zhong),工作原理也可(ke)分為(wei)電(dian)(dian)壓型和電(dian)(dian)流(liu)型、諧振型驅動(dong)等。這(zhe)些同(tong)(tong)步(bu)驅動(dong)的方(fang)(fang)(fang)(fang)式(shi)各自有其(qi)優勢和不(bu)足。其(qi)中(zhong)一(yi)種(zhong)較為(wei)實用的是電(dian)(dian)流(liu)同(tong)(tong)步(bu)的控制驅動(dong)方(fang)(fang)(fang)(fang)案,但是因為(wei)驅動(dong)中(zhong)選擇了場效應晶(jing)體管門極(ji)(ji)驅動(dong)電(dian)(dian)壓鉗位在輸出(chu)電(dian)(dian)壓上,而門極(ji)(ji)穿電(dian)(dian)壓通常(chang)較低(di),因此(ci)要采用此(ci)種(zhong)方(fang)(fang)(fang)(fang)法(fa)(fa)就要降低(di)輸出(chu)電(dian)(dian)壓。

所(suo)以(yi)可以(yi)采用(yong)(yong)混合型(xing)的(de)(de)(de)同步整流(liu)(liu)方(fang)法,其工作的(de)(de)(de)原理(li)為在(zai)(zai)兩(liang)個變(bian)壓(ya)器(qi)上(shang)的(de)(de)(de)兩(liang)個繞(rao)(rao)(rao)組(zu)為T3、T4,其中(zhong)T3設(she)計(ji)為二次繞(rao)(rao)(rao)組(zu)主(zhu)要負(fu)責能量的(de)(de)(de)傳遞(di),T4則為輔助(zhu)繞(rao)(rao)(rao)組(zu)。在(zai)(zai)T4上(shang)的(de)(de)(de)電(dian)壓(ya)隨著T3電(dian)壓(ya)的(de)(de)(de)升高而升高,用(yong)(yong)于開(kai)啟同步整流(liu)(liu)用(yong)(yong)場(chang)效應(ying)管(guan)(guan)。此時的(de)(de)(de)電(dian)流(liu)(liu)互感器(qi)中(zhong)的(de)(de)(de)兩(liang)個繞(rao)(rao)(rao)組(zu)也起(qi)到不(bu)同的(de)(de)(de)作用(yong)(yong),初級(ji)繞(rao)(rao)(rao)組(zu)是(shi)串聯在(zai)(zai)主(zhu)電(dian)路中(zhong),是(shi)檢驗流(liu)(liu)經的(de)(de)(de)場(chang)效應(ying)管(guan)(guan)的(de)(de)(de)電(dian)流(liu)(liu) ,當(dang)該繞(rao)(rao)(rao)組(zu)中(zhong)的(de)(de)(de)電(dian)流(liu)(liu)下降到0的(de)(de)(de)時候(hou),另一個繞(rao)(rao)(rao)組(zu)則將場(chang)效應(ying)管(guan)(guan)斷開(kai)。所(suo)以(yi)此種方(fang)案可以(yi)利用(yong)(yong)電(dian)壓(ya)信號(hao)來(lai)控(kong)制場(chang)效應(ying)晶體管(guan)(guan)的(de)(de)(de)導(dao)通,電(dian)流(liu)(liu)信號(hao)澤爾負(fu)責其關(guan)閉,不(bu)僅僅提高了效率(lv)還可以(yi)穩定的(de)(de)(de)工作,控(kong)制了無開(kai)通的(de)(de)(de)情況。

2.4 變壓器(qi)的高效率設計

高(gao)頻(pin)率(lv)變(bian)(bian)(bian)壓(ya)器(qi)是隔(ge)離(li)形(xing)式的(de)電源中(zhong)不可或缺的(de)器(qi)件,在(zai)提(ti)升效(xiao)(xiao)率(lv)的(de)方面(mian)也(ye)有(you)著重要(yao)的(de)作(zuo)用(yong)。變(bian)(bian)(bian)壓(ya)的(de)損(sun)耗主(zhu)要(yao)來自銅損(sun)、鐵(tie)損(sun)、漏感損(sun)耗,此三(san)者的(de)損(sun)耗可以(yi)(yi)(yi)通過必要(yao)的(de)手段(duan)進性(xing)損(sun)耗的(de)控制,但(dan)是控制的(de)措施不能完全達(da)到(dao)綜合(he)高(gao)效(xiao)(xiao)的(de)目標效(xiao)(xiao)果。因此,新型的(de)變(bian)(bian)(bian)壓(ya)器(qi)技(ji)術(shu)(shu)將(jiang)高(gao)頻(pin)率(lv)供電系統進行了(le)升級(ji)。此種變(bian)(bian)(bian)壓(ya)器(qi)的(de)技(ji)術(shu)(shu)日趨成熟,主(zhu)要(yao)特點(dian)是高(gao)度低,利用(yong)底部(bu)面(mian)積大的(de)平面(mian)磁芯(xin)。此種變(bian)(bian)(bian)壓(ya)器(qi)采用(yong)的(de)繞著是螺旋(xuan)印制線構成。和(he)以(yi)(yi)(yi)往(wang)的(de)變(bian)(bian)(bian)壓(ya)器(qi)相(xiang)比此種平面(mian)型的(de)變(bian)(bian)(bian)壓(ya)效(xiao)(xiao)果更高(gao),工(gong)作(zuo)效(xiao)(xiao)率(lv)也(ye)得(de)到(dao)了(le)提(ti)升,且體積小(xiao)、漏感小(xiao)、導熱(re)性(xing)好、一致性(xing)強等。雖(sui)然(ran)其距離(li)應用(yong)還有(you)一段(duan)時(shi)間,但(dan)是可以(yi)(yi)(yi)成為高(gao)端應用(yong)領(ling)域的(de)替代(dai)產品。

3結論

LED路燈(deng)(deng)系統的高效(xiao)率(lv)電(dian)源驅動器(qi)的設計(ji),其(qi)首要的目的就是保證(zheng)路燈(deng)(deng)的高頻率(lv)工況(kuang),同時防止供電(dian)系統中的干擾(rao)侵入到路燈(deng)(deng)系統中而(er)造成損(sun)壞。其(qi)次,利(li)用多種復合電(dian)路和(he)晶(jing)體管來提高供電(dian)過(guo)程(cheng)中的各種線路損(sun)耗,提高供電(dian)的效(xiao)率(lv),以此(ci)達到安全、高效(xiao)的目的。

參考文獻

[1]魏(wei)大(da)為.大(da)功率LED路燈驅動(dong)電源的設計[J].電工技術,2009(5).

[2]張國雋.城市路燈照明節能(neng)方(fang)案的設計[J].廣(guang)東科技,2007(S2).

篇5

關鍵(jian)詞:半導體激光器;驅動電路(lu);慢啟動

中圖分類號(hao):TM1 文獻標識碼:A文章編(bian)號(hao):1006-4311(2012)04-0045-010引言

隨著半導(dao)體(ti)在通信、測控、醫療、集成(cheng)光學等技術領域(yu)的(de)(de)廣泛應用(yong)(yong),它越(yue)來越(yue)受(shou)到人們的(de)(de)關注,為其設(she)計一款(kuan)精度較高、性(xing)能(neng)可靠、經濟(ji)、耐用(yong)(yong)的(de)(de)驅動電源(yuan)成(cheng)了我們當前(qian)最(zui)為緊要的(de)(de)問題,由于半導(dao)體(ti)激光器“嬌貴”的(de)(de)特點,所使用(yong)(yong)的(de)(de)電源(yuan)必須要在性(xing)能(neng)與質(zhi)量(liang)上嚴格把關。

1半導體激光器(qi)轉移特性

在一定(ding)溫度(du)(du)(du)下,當(dang)驅(qu)動電(dian)(dian)流低于閾值電(dian)(dian)流時(shi),激(ji)(ji)(ji)光器(qi)輸(shu)(shu)出光功(gong)率(lv)P近似為零,半(ban)導(dao)體(ti)激(ji)(ji)(ji)光器(qi)只(zhi)能發(fa)熒光。驅(qu)動電(dian)(dian)流高于閾值時(shi)輸(shu)(shu)出激(ji)(ji)(ji)光,并且光輸(shu)(shu)出功(gong)率(lv)隨著(zhu)驅(qu)動電(dian)(dian)流的(de)增(zeng)大(da)而(er)迅(xun)速(su)增(zeng)加并呈線性(xing)關(guan)系。在實(shi)際(ji)應用中必須(xu)對激(ji)(ji)(ji)光二極管提出兩(liang)個要(yao)求,一是較低的(de)門(men)限電(dian)(dian)流,二是穩定(ding)的(de)P-I曲線。從原理上來講,在工作物質一定(ding)的(de)情況下,半(ban)導(dao)體(ti)激(ji)(ji)(ji)光器(qi)輸(shu)(shu)出的(de)激(ji)(ji)(ji)光頻率(lv)應當(dang)由(you)諧(xie)振腔長度(du)(du)(du)和激(ji)(ji)(ji)勵源的(de)強度(du)(du)(du)有關(guan),換句話說,半(ban)導(dao)體(ti)激(ji)(ji)(ji)光器(qi)的(de)輸(shu)(shu)出頻率(lv)取決于:PN結的(de)溫度(du)(du)(du)和注入電(dian)(dian)流的(de)大(da)小。另外,由(you)于半(ban)導(dao)體(ti)PN結相當(dang)脆(cui)弱,稍有電(dian)(dian)流沖擊就(jiu)會造成損害。所(suo)以在具體(ti)使用半(ban)導(dao)體(ti)激(ji)(ji)(ji)光器(qi)時(shi),我們對其供電(dian)(dian)電(dian)(dian)路(lu)和調(diao)制電(dian)(dian)路(lu)的(de)要(yao)求相當(dang)嚴格(ge)。

我們用異(yi)質結來(lai)代替同質結就可以將(jiang)門限電流降低(di)兩個數量級(ji),而對于穩定性問題目(mu)前只有(you)通(tong)過外加恒溫(wen)和(he)光(guang)(guang)(guang)(guang)(guang)(guang)反饋等來(lai)加以改善。對一般(ban)的(de)(de)半導體(ti)激光(guang)(guang)(guang)(guang)(guang)(guang)器來(lai)說,激光(guang)(guang)(guang)(guang)(guang)(guang)二極(ji)管是正向結法(fa),光(guang)(guang)(guang)(guang)(guang)(guang)電二極(ji)管是反向結法(fa)。受光(guang)(guang)(guang)(guang)(guang)(guang)后轉(zhuan)換的(de)(de)光(guang)(guang)(guang)(guang)(guang)(guang)電流在電阻上以電壓形式(shi)反映出射光(guang)(guang)(guang)(guang)(guang)(guang)功率的(de)(de)大小,添(tian)加控制(zhi)電路(lu)就可以達到控制(zhi)發光(guang)(guang)(guang)(guang)(guang)(guang)功率的(de)(de)目(mu)的(de)(de)。

2電路設計

試驗(yan)中所用(yong)激光二極管(guan)型號為HT670T5,該管(guan)波長為650nm,額定功率為30mW。

2.1 電(dian)(dian)(dian)流源(yuan)(yuan)電(dian)(dian)(dian)路(lu)線(xian)(xian)性(xing)電(dian)(dian)(dian)源(yuan)(yuan)具(ju)有精度高、穩(wen)定度高但是效率(lv)較低的(de)(de)(de)特點,但考慮到半導體激光器(qi)對電(dian)(dian)(dian)源(yuan)(yuan)精度的(de)(de)(de)苛刻要(yao)(yao)求(qiu),而(er)且我們(men)設計(ji)的(de)(de)(de)電(dian)(dian)(dian)源(yuan)(yuan)是一種小功率(lv)電(dian)(dian)(dian)源(yuan)(yuan),效率(lv)低的(de)(de)(de)缺點就(jiu)顯(xian)得(de)不是特別重要(yao)(yao),所(suo)以我們(men)設計(ji)方案(an)選擇(ze)線(xian)(xian)性(xing)電(dian)(dian)(dian)源(yuan)(yuan)。

為了實(shi)現(xian)精度和穩(wen)定度的要求(qiu),實(shi)現(xian)抑制紋波和降低噪聲的要求(qiu)。設計了兩級調整模塊,前一(yi)(yi)級使用穩(wen)壓(ya)芯(xin)片,通過擴(kuo)流,輸送到后一(yi)(yi)級調整模塊。

市電通過電網(wang)濾波(bo)器進入(ru)變壓器,降(jiang)至21V(峰值),經過整流(liu)濾波(bo)(具(ju)體電路省略)后(hou)通過由穩壓集(ji)成(cheng)塊與擴流(liu)電路組成(cheng)的一級調整電路;之后(hou),通過后(hou)級的串聯—取樣—反饋—調整,最后(hou)輸出。

在(zai)具體恒流源電(dian)(dian)路設計中,負(fu)載(zai)(zai)不是加在(zai)它的(de)輸(shu)出端(duan)(duan),而(er)是加在(zai)調壓器LM317T的(de)輸(shu)入端(duan)(duan)。對于(yu)實(shi)際負(fu)載(zai)(zai)來說,調壓器LM317T的(de)輸(shu)入起恒流源作用。因為(wei)調壓器輸(shu)出端(duan)(duan)接的(de)是虛假負(fu)載(zai)(zai)R1,所以不論實(shi)際負(fu)載(zai)(zai)兩(liang)端(duan)(duan)電(dian)(dian)壓的(de)真(zhen)實(shi)值是多少,它都消(xiao)耗一個(ge)恒定(ding)不變的(de)電(dian)(dian)流。調壓器和(he)虛假負(fu)載(zai)(zai)R1上的(de)電(dian)(dian)壓使電(dian)(dian)路總允許(xu)電(dian)(dian)壓下降。負(fu)載(zai)(zai)電(dian)(dian)流由R1設定(ding),其值等于(yu)1.25A/Ω×R1。

2.2 紋(wen)波(bo)調(diao)零(ling)電(dian)路為了減(jian)小(xiao)穩(wen)流電(dian)源的(de)紋(wen)波(bo)電(dian)壓,需要為電(dian)路增(zeng)設紋(wen)波(bo)調(diao)零(ling)電(dian)路,在正常工作中,調(diao)節(jie)紋(wen)波(bo)調(diao)零(ling)電(dian)位器可使輸出(chu)紋(wen)波(bo)電(dian)壓非常小(xiao)。紋(wen)波(bo)成(cheng)分通過電(dian)容耦合至運放(fang)的(de)反(fan)相輸入(ru)端,在具體的(de)紋(wen)波(bo)調(diao)零(ling)電(dian)路中,它經(jing)放(fang)大后加至調(diao)整管的(de)基極。因(yin)此,可達到(dao)上述的(de)效(xiao)果。

2.3 保(bao)護(hu)電(dian)(dian)(dian)路(lu)實(shi)際應用(yong)(yong)中,激光(guang)器很容易受到同電(dian)(dian)(dian)路(lu)其它電(dian)(dian)(dian)器干(gan)擾產生的(de)(de)浪涌電(dian)(dian)(dian)流的(de)(de)傷害,為(wei)保(bao)護(hu)激光(guang)器不受到浪涌電(dian)(dian)(dian)流的(de)(de)沖擊(ji),我們可以在(zai)電(dian)(dian)(dian)路(lu)中加入慢啟動電(dian)(dian)(dian)路(lu)。此外,為(wei)更好(hao)的(de)(de)保(bao)護(hu)激光(guang)器,我們可選用(yong)(yong)2SA1015和2SC1815等類(lei)型(xing)(xing)的(de)(de)吸流管,在(zai)電(dian)(dian)(dian)壓源(yuan)的(de)(de)制(zhi)作過程(cheng)中基(ji)本可保(bao)護(hu)激光(guang)器的(de)(de)安全運(yun)行。加上電(dian)(dian)(dian)壓源(yuan)中電(dian)(dian)(dian)網(wang)濾波(bo)器的(de)(de)作用(yong)(yong),將(jiang)電(dian)(dian)(dian)路(lu)制(zhi)作成簡單的(de)(de)限流型(xing)(xing)保(bao)護(hu)電(dian)(dian)(dian)路(lu)。

3實驗結果

本文所設計的(de)驅動電(dian)源,通(tong)過(guo)慢(man)啟動、紋波調零等電(dian)路,在(zai)實驗室中(zhong)的(de)應用(yong)效果(guo)良好,較好的(de)解決了半導體(ti)二極管(guan)在(zai)使用(yong)中(zhong)輸出功(gong)率不穩(wen)定的(de)問題(ti),測量結(jie)果(guo)如下:

考慮示波器的帶寬限制,修(xiu)正為:

電流源:

電流紋波及噪聲:?燮(xie)0.1uA

電壓源:

紋波:?燮(xie)0.01mV

電流紋波及噪聲:?燮0.5uA

調整范圍:0-500mA

參考文獻:

篇6

關鍵詞: 動態光調節; 數字式LED驅動電源; 嵌入式設計; C8051F021

中(zhong)圖分(fen)類號(hao): TN86?34; TP303.3 文(wen)獻標識碼: A 文(wen)章(zhang)編號(hao): 1004?373X(2017)10?0103?04

Abstract: The adjustment of LED controlled by dynamic light can′t achieve the expected effect due to the imperfect design of digital LED driving power supply adjusted by dynamic light, but the embedded system can improve the performances of LED driving power supply effectively. An embedded system based digital LED driving power supply controlled by dynamic light was designed. The A/D acquisition module performs the acquisition, rectification, filtering and A/D conversion of data of digital LED adjusted by dynamic light to get the A/D sampling data, and transfer it to the driving circuit. The embedded design is adopted in the driving circuit to optimize the A/D sampling data, so as to control the LED lighting reasonably and regulate the digital LED with dynamic light effectively. The C8051F021 chip is the "manager" of the embedded system based digital LED driving power supply under dynamic light control. Its management flow chart is given in the third part of this paper. The data acquisition language of A/D acquisition module was design also in the third part. The experimental results show that the designed digital LED driving power supply has strong driving performance and high power conversion efficiency.

Keywords: dynamic light control; digital LED driving power supply; embedded design; C8051F021

0 引 言

現如(ru)今,數(shu)字(zi)式(shi)(shi)LED以其(qi)低耗、顯(xian)示清晰(xi)、壽命(ming)長等優點,在家用電(dian)(dian)器的(de)(de)(de)顯(xian)示配件(jian)方面占據了主(zhu)導(dao)地位。動(dong)(dong)(dong)態(tai)光(guang)調(diao)節(jie)是一種能(neng)夠有(you)效縮減數(shu)字(zi)式(shi)(shi)LED顯(xian)示屏漏(lou)光(guang)現象、增強顯(xian)示效果(guo)的(de)(de)(de)方法,但由(you)于(yu)動(dong)(dong)(dong)態(tai)光(guang)調(diao)節(jie)下(xia)的(de)(de)(de)數(shu)字(zi)式(shi)(shi)LED驅(qu)動(dong)(dong)(dong)電(dian)(dian)源(yuan)(yuan)的(de)(de)(de)設計(ji)不完善,使動(dong)(dong)(dong)態(tai)光(guang)對LED的(de)(de)(de)調(diao)節(jie)無法達到預期效果(guo),這(zhe)已成為(wei)(wei)科研組織的(de)(de)(de)研究(jiu)難題(ti)[1?4]。嵌(qian)入式(shi)(shi)是一種以應用為(wei)(wei)核心、以電(dian)(dian)子信(xin)息技術為(wei)(wei)根基的(de)(de)(de)計(ji)算(suan)機系(xi)統,其(qi)能(neng)夠調(diao)控軟硬(ying)件(jian)的(de)(de)(de)靈活(huo)性(xing),進而(er)提升LED驅(qu)動(dong)(dong)(dong)電(dian)(dian)源(yuan)(yuan)的(de)(de)(de)各(ge)項性(xing)能(neng)[5?6]。為(wei)(wei)此,利用嵌(qian)入式(shi)(shi)系(xi)統,設計(ji)動(dong)(dong)(dong)態(tai)光(guang)調(diao)節(jie)下(xia)的(de)(de)(de)數(shu)字(zi)式(shi)(shi)LED驅(qu)動(dong)(dong)(dong)電(dian)(dian)源(yuan)(yuan),增強數(shu)字(zi)式(shi)(shi)LED驅(qu)動(dong)(dong)(dong)電(dian)(dian)源(yuan)(yuan)的(de)(de)(de)驅(qu)動(dong)(dong)(dong)性(xing)能(neng)和(he)轉換效率,實現動(dong)(dong)(dong)態(tai)光(guang)對數(shu)字(zi)式(shi)(shi)LED的(de)(de)(de)調(diao)節(jie)效果(guo)。

科(ke)研組(zu)織對動(dong)(dong)(dong)(dong)(dong)態(tai)光(guang)調節(jie)下數字式LED驅(qu)動(dong)(dong)(dong)(dong)(dong)電(dian)(dian)源的設計成果均存在一些不足之處。如文獻[7]提出(chu)(chu)的能(neng)耗密(mi)度分配(pei)模型方法(fa)。這種(zhong)方法(fa)能(neng)夠(gou)將動(dong)(dong)(dong)(dong)(dong)態(tai)光(guang)調節(jie)下數字式LED驅(qu)動(dong)(dong)(dong)(dong)(dong)電(dian)(dian)源的多余(yu)能(neng)耗合(he)理分配(pei)出(chu)(chu)去,達(da)到增強電(dian)(dian)源轉換效(xiao)率的目的;但這種(zhong)方法(fa)過于受(shou)限于電(dian)(dian)源傳(chuan)送功率配(pei)對,故其驅(qu)動(dong)(dong)(dong)(dong)(dong)性能(neng)較低。文獻[8]提出(chu)(chu)基(ji)于阻(zu)(zu)抗模型構建動(dong)(dong)(dong)(dong)(dong)態(tai)光(guang)調節(jie)下數字式LED驅(qu)動(dong)(dong)(dong)(dong)(dong)電(dian)(dian)源的方法(fa),阻(zu)(zu)抗模型能(neng)夠(gou)較為合(he)理實現電(dian)(dian)源驅(qu)動(dong)(dong)(dong)(dong)(dong)的高性能(neng);但這種(zhong)方法(fa)的耗能(neng)較大(da),電(dian)(dian)源轉換效(xiao)率不高。

從以上動態光調(diao)(diao)節(jie)下數字式(shi)LED驅(qu)動電源(yuan)的設計(ji)成果中可看出,我國科研(yan)組織(zhi)對基(ji)于(yu)嵌入式(shi)系統的動態光調(diao)(diao)節(jie)下數字式(shi)LED驅(qu)動電源(yuan)的設計(ji)迫(po)在眉睫。

1 數字式(shi)LED驅動電源嵌入式(shi)設計

1.1 LED驅(qu)動電源整體(ti)設(she)計

基于嵌入式(shi)系統的猶光調(diao)節下數字式(shi)LED驅動電源的工(gong)作原理如(ru)圖1所示。

由圖1可(ke)知,在基于嵌入式(shi)(shi)系(xi)統的(de)動(dong)(dong)(dong)態光調(diao)節下數(shu)(shu)(shu)字式(shi)(shi)LED驅(qu)動(dong)(dong)(dong)電(dian)源(yuan)的(de)設計(ji)中,A/D采集模(mo)塊(kuai)對數(shu)(shu)(shu)字式(shi)(shi)LED數(shu)(shu)(shu)據進行整流(liu)、濾(lv)波、A/D采樣,其(qi)對數(shu)(shu)(shu)字式(shi)(shi)LED驅(qu)動(dong)(dong)(dong)電(dian)源(yuan)有著過渡作用,是(shi)數(shu)(shu)(shu)字式(shi)(shi)LED驅(qu)動(dong)(dong)(dong)電(dian)源(yuan)的(de)基礎(chu)組成部分(fen)。驅(qu)動(dong)(dong)(dong)電(dian)路是(shi)實現數(shu)(shu)(shu)字式(shi)(shi)LED驅(qu)動(dong)(dong)(dong)電(dian)源(yuan)對動(dong)(dong)(dong)態光調(diao)節控制(zhi)的(de)基礎(chu),高(gao)性能(neng)(neng)的(de)驅(qu)動(dong)(dong)(dong)電(dian)路能(neng)(neng)夠給予數(shu)(shu)(shu)字式(shi)(shi)LED驅(qu)動(dong)(dong)(dong)電(dian)源(yuan)較(jiao)高(gao)的(de)驅(qu)動(dong)(dong)(dong)性能(neng)(neng)。控制(zhi)芯(xin)片是(shi)數(shu)(shu)(shu)字式(shi)(shi)LED驅(qu)動(dong)(dong)(dong)電(dian)源(yuan)的(de)控制(zhi)核心,其(qi)管(guan)理著整個數(shu)(shu)(shu)字式(shi)(shi)LED驅(qu)動(dong)(dong)(dong)電(dian)源(yuan)的(de)工(gong)作流(liu)程(cheng)。

1.2 A/D采集(ji)模塊設計(ji)

在A/D采集模(mo)塊中,整流(liu)(liu)是(shi)將采集到的(de)動(dong)態光調節下的(de)數(shu)字式(shi)LED的(de)交(jiao)流(liu)(liu)電(dian)近(jin)似(si)(si)轉化為直(zhi)流(liu)(liu)電(dian)的(de)過程;濾波是(shi)將近(jin)似(si)(si)直(zhi)流(liu)(liu)電(dian)中的(de)交(jiao)流(liu)(liu)波形去除(chu),最終(zhong)輸出標準(zhun)直(zhi)流(liu)(liu)電(dian)的(de)過程。圖2是(shi)濾波器電(dian)路圖。

濾(lv)(lv)波是排(pai)除電(dian)(dian)力干(gan)擾的一項重要(yao)手段,其能夠避(bi)免電(dian)(dian)源(yuan)損傷、使電(dian)(dian)路元件維持在正常狀態下(xia)(xia)工作。由圖2可知,A/D采(cai)集模塊選用(yong)低(di)通濾(lv)(lv)波器(qi)(qi)為(wei)動態光調(diao)節下(xia)(xia)的數字(zi)式(shi)LED進(jin)行(xing)濾(lv)(lv)波,其能夠進(jin)行(xing)50 Hz電(dian)(dian)力信號的濾(lv)(lv)波,對高頻干(gan)擾的衰(shuai)減效果較強(qiang)。所設計的低(di)通濾(lv)(lv)波器(qi)(qi)擁有2個輸(shu)入、輸(shu)出端口,并(bing)配備(bei)1個電(dian)(dian)源(yuan)接地端。C,C1代(dai)表(biao)差模濾(lv)(lv)波電(dian)(dian)容,C2,C3代(dai)表(biao)共(gong)模濾(lv)(lv)波電(dian)(dian)容,L1,L2代(dai)表(biao)電(dian)(dian)感,T代(dai)表(biao)共(gong)模電(dian)(dian)感。如果出現(xian)干(gan)擾信號,電(dian)(dian)感則(ze)會(hui)高速增長,阻止干(gan)擾信號通過,進(jin)而實現(xian)對動態光調(diao)節下(xia)(xia)數字(zi)式(shi)LED的濾(lv)(lv)波。整流濾(lv)(lv)波之后,A/D采(cai)集模塊將對其獲取到的數據進(jin)行(xing)A/D采(cai)樣,圖3是A/D采(cai)樣電(dian)(dian)路圖。

由(you)圖3可知,A/D采集(ji)(ji)模(mo)(mo)塊(kuai)主要由(you)對(dui)(dui)比器(qi)(qi)、寄(ji)(ji)(ji)存器(qi)(qi)和A/D轉(zhuan)換器(qi)(qi)組(zu)成(cheng)(cheng),其最(zui)重(zhong)要的組(zu)成(cheng)(cheng)元(yuan)件是A/D轉(zhuan)換器(qi)(qi)。A/D采集(ji)(ji)模(mo)(mo)塊(kuai)將其最(zui)初采集(ji)(ji)到的動(dong)態光調(diao)(diao)節(jie)下的數字(zi)式LED數據,利用對(dui)(dui)比器(qi)(qi)提高數據分(fen)辨率,并暫存在(zai)寄(ji)(ji)(ji)存器(qi)(qi)中(zhong)。用戶(hu)可對(dui)(dui)寄(ji)(ji)(ji)存器(qi)(qi)處理流程進(jin)行編程,A/D轉(zhuan)換器(qi)(qi)會對(dui)(dui)寄(ji)(ji)(ji)存器(qi)(qi)中(zhong)的數據進(jin)行依次調(diao)(diao)用,進(jin)行模(mo)(mo)/數轉(zhuan)換。

模(mo)/數(shu)(shu)轉換(huan)的方式采(cai)用高(gao)速形式,以(yi)增強基(ji)于(yu)嵌入式系統的動(dong)態光調節下(xia)數(shu)(shu)字(zi)式LED驅(qu)動(dong)電源的驅(qu)動(dong)性能(neng)和(he)電源轉換(huan)效(xiao)(xiao)率。A/D轉換(huan)器(qi)的輸出(chu)結果會經由對比器(qi)與(yu)最初采(cai)集數(shu)(shu)據進行比較,如果對比器(qi)的對比結果是負數(shu)(shu),A/D采(cai)集模(mo)塊(kuai)將把寄(ji)存器(qi)狀態調至高(gao)效(xiao)(xiao)位;反之,則調至低效(xiao)(xiao)位。

寄(ji)(ji)存器(qi)(qi)的效位狀態(tai)(tai)會對A/D采集模塊(kuai)的效率產(chan)生影響,通過(guo)不(bu)斷調整寄(ji)(ji)存器(qi)(qi)效位狀態(tai)(tai),能(neng)夠(gou)提高數(shu)字式LED驅(qu)動(dong)電(dian)(dian)源(yuan)的工作(zuo)效率。最后,A/D采集模塊(kuai)利用控制與定(ding)時(shi)邏(luo)輯(ji)原理,將其獲取到的A/D采樣數(shu)據輸出到驅(qu)動(dong)電(dian)(dian)路。

1.3 驅(qu)動電路嵌入式(shi)設計

受限于我(wo)國的(de)(de)科技能(neng)力,數字式(shi)LED的(de)(de)單顆發光(guang)物質(zhi)功率過低,在實際應用(yong)中,只有將多(duo)顆發光(guang)物質(zhi)連接(jie)起來(lai)使用(yong)才(cai)能(neng)夠實現LED的(de)(de)肉眼可視發光(guang),連接(jie)方式(shi)主要采用(yong)串聯和并(bing)聯的(de)(de)混(hun)合連接(jie)。為此,必(bi)須通過特定的(de)(de)驅動(dong)電路才(cai)能(neng)夠令動(dong)態光(guang)調節下的(de)(de)數字式(shi)LED完成正常(chang)顯示功能(neng),所設計驅動(dong)電路采用(yong)嵌入式(shi)。

反(fan)激(ji)式轉換器是一(yi)種擁有簡單拓撲(pu)結構的(de)電(dian)(dian)源開關,其(qi)能(neng)夠為(wei)(wei)驅動電(dian)(dian)路提供較(jiao)高水平(ping)的(de)電(dian)(dian)壓升降和(he)多路輸出。為(wei)(wei)此,基于嵌入(ru)式系統(tong)的(de)動態光調節(jie)下(xia)數(shu)字(zi)式LED驅動電(dian)(dian)源的(de)設計(ji)中,將(jiang)反(fan)激(ji)式轉換器納入(ru)到驅動電(dian)(dian)路,并利用隔離式轉換器維持(chi)數(shu)字(zi)式LED的(de)正常發(fa)光。圖4為(wei)(wei)驅動電(dian)(dian)路電(dian)(dian)路圖。

由圖4可(ke)知,所設(she)計的(de)(de)(de)驅(qu)動電(dian)(dian)(dian)(dian)路(lu)(lu)有著成本低、效(xiao)率(lv)高的(de)(de)(de)特點(dian),能夠實現對LED發(fa)光(guang)的(de)(de)(de)合(he)理控(kong)(kong)制。驅(qu)動電(dian)(dian)(dian)(dian)路(lu)(lu)能夠容納的(de)(de)(de)輸(shu)入(ru)電(dian)(dian)(dian)(dian)壓范圍是(shi)[170 V,280 V],LED發(fa)光(guang)物質的(de)(de)(de)連(lian)接方式是(shi)15顆(ke)串聯、5顆(ke)并聯,電(dian)(dian)(dian)(dian)流(liu)、電(dian)(dian)(dian)(dian)壓和功率(lv)的(de)(de)(de)極大(da)輸(shu)出值分別為350 mA,DC 60 V和20 W。A/D采集模塊會(hui)將其獲取到A/D采樣數(shu)據輸(shu)入(ru)到驅(qu)動電(dian)(dian)(dian)(dian)路(lu)(lu),驅(qu)動電(dian)(dian)(dian)(dian)路(lu)(lu)的(de)(de)(de)輸(shu)出接收元件是(shi)單(dan)片機。基于嵌入(ru)式系統的(de)(de)(de)動態(tai)(tai)光(guang)調(diao)節(jie)下數(shu)字式LED驅(qu)動電(dian)(dian)(dian)(dian)源為驅(qu)動電(dian)(dian)(dian)(dian)路(lu)(lu)的(de)(de)(de)連(lian)接設(she)計成嵌入(ru)式連(lian)接,驅(qu)動電(dian)(dian)(dian)(dian)路(lu)(lu)對數(shu)字式LED發(fa)光(guang)的(de)(de)(de)控(kong)(kong)制并非只有簡單(dan)的(de)(de)(de)開啟和關閉(bi),而是(shi)能夠合(he)理調(diao)節(jie)數(shu)字式LED的(de)(de)(de)發(fa)光(guang)亮度,以提高其使用(yong)壽命、增強(qiang)動態(tai)(tai)光(guang)對數(shu)字化LED的(de)(de)(de)調(diao)節(jie)效(xiao)果。

1.4 控制芯片O計

控制芯(xin)片(pian)是基于(yu)嵌入(ru)式系統的(de)動(dong)態光(guang)調節下數(shu)(shu)字式LED驅動(dong)電源的(de)“管理者”,故(gu)在控制芯(xin)片(pian)的(de)選擇上應絕對符(fu)合數(shu)(shu)字式LED驅動(dong)電源的(de)設計初衷,這(zhe)就要求所選擇的(de)控制芯(xin)片(pian)應具有高(gao)集成度和處理效率。因此,選擇某公司出產(chan)的(de)C8051F021芯(xin)片(pian)作為數(shu)(shu)字式LED驅動(dong)電源的(de)控制芯(xin)片(pian),此芯(xin)片(pian)的(de)性(xing)能較高(gao)且(qie)能夠獨立進行高(gao)效的(de)控制工作。

C8051F021芯(xin)(xin)片是一種擁有CIP?51 內(nei)(nei)核的(de)芯(xin)(xin)片,是對8051系列芯(xin)(xin)片的(de)優化(hua)成果。CIP?51 內(nei)(nei)核擁有高兼容性和流(liu)水線結構,能夠通過(guo)803x/805x編碼(ma)器(qi)對其進行(xing)開發(fa)。CIP?51 內(nei)(nei)核配備了5個(ge)16位定時器(qi)、2個(ge)通用異步(bu)收發(fa)傳(chuan)輸(shu)器(qi)、1個(ge)256 B隨機存取存儲(chu)器(qi)以(yi)及1個(ge)特殊(shu)功能的(de)寄存器(qi),可實現對控制(zhi)指令的(de)完美(mei)操作。

C8051F021芯片(pian)的(de)內部組成并不簡單,這(zhe)為其自身功能的(de)完善提供了較為有利的(de)元件(jian)支持。C8051F021芯片(pian)內置看門狗計(ji)時(shi)器、電(dian)(dian)源(yuan)監(jian)聽監(jian)控設(she)備、視(shi)頻存儲(chu)設(she)備以(yi)及時(shi)鐘振蕩器,其中(zhong)的(de)視(shi)頻存儲(chu)設(she)備可(ke)對基于嵌入式(shi)系統的(de)動態(tai)光調節下數(shu)(shu)字(zi)式(shi)LED驅動電(dian)(dian)源(yuan)進(jin)行再編(bian)碼和更新。但由于經(jing)再編(bian)碼后的(de)數(shu)(shu)據容易丟失(shi),故在使用(yong)此功能前必(bi)須對數(shu)(shu)字(zi)式(shi)LED驅動電(dian)(dian)源(yuan)的(de)數(shu)(shu)據類型(xing)進(jin)行檢測。

2 數字式LED驅動(dong)電源嵌入(ru)式軟件設(she)計

2.1 C8051F021芯片(pian)管理流(liu)程(cheng)設計(ji)

基于嵌(qian)入式系統的動態光調(diao)節(jie)下數(shu)字式LED驅動電源的軟(ruan)件部(bu)分(fen)為C8051F021芯片(pian)的管(guan)理流程(cheng)進行了設(she)計,如(ru)圖5所示。

圖5中,C8051F021芯(xin)片(pian)所需進(jin)(jin)(jin)行(xing)(xing)的(de)(de)(de)(de)初(chu)始化(hua)包括看(kan)門(men)狗(gou)計時器參數重(zhong)置(zhi)、接口輸出配置(zhi)以(yi)及編程單元參數設(she)定,軟件(jian)也會(hui)同(tong)時對A/D轉換(huan)器進(jin)(jin)(jin)行(xing)(xing)初(chu)始化(hua)。如果控(kong)(kong)制(zhi)(zhi)信號不存(cun)在(zai),用(yong)戶(hu)則可(ke)手動(dong)切換(huan)控(kong)(kong)制(zhi)(zhi)模(mo)(mo)(mo)式(shi),否(fou)則將默認(ren)為自動(dong)調光(guang)模(mo)(mo)(mo)式(shi);如果控(kong)(kong)制(zhi)(zhi)信號存(cun)在(zai),初(chu)始化(hua)后(hou)的(de)(de)(de)(de)C8051F021芯(xin)片(pian)將會(hui)自動(dong)接收控(kong)(kong)制(zhi)(zhi)信號,并(bing)進(jin)(jin)(jin)行(xing)(xing)LED發光(guang)控(kong)(kong)制(zhi)(zhi)模(mo)(mo)(mo)式(shi)的(de)(de)(de)(de)設(she)定。在(zai)C8051F021芯(xin)片(pian)進(jin)(jin)(jin)行(xing)(xing)管理(li)工作(zuo)的(de)(de)(de)(de)過程中,用(yong)戶(hu)如果需要切換(huan)控(kong)(kong)制(zhi)(zhi)模(mo)(mo)(mo)式(shi),應在(zai)設(she)定控(kong)(kong)制(zhi)(zhi)模(mo)(mo)(mo)式(shi)后(hou)選擇切換(huan)模(mo)(mo)(mo)式(shi),否(fou)則只(zhi)能選擇在(zai)基(ji)于(yu)嵌入式(shi)系統的(de)(de)(de)(de)動(dong)態光(guang)調節下和數字(zi)式(shi)LED驅動(dong)電源(yuan)未工作(zuo)的(de)(de)(de)(de)情況下進(jin)(jin)(jin)行(xing)(xing)切換(huan)。這樣設(she)計有(you)助于(yu)維持數字(zi)式(shi)LED驅動(dong)電源(yuan)的(de)(de)(de)(de)工作(zuo)連貫性(xing),提高驅動(dong)性(xing)能。

2.2 數據采集語言設(she)計

3 實驗驗證

3.1 驅動(dong)性能驗證

對本文(wen)設(she)計(ji)的基于嵌入式(shi)(shi)(shi)系統的動(dong)(dong)態(tai)光(guang)調節(jie)下(xia)數(shu)字(zi)式(shi)(shi)(shi)LED驅(qu)動(dong)(dong)電(dian)(dian)源(yuan)的驅(qu)動(dong)(dong)性(xing)能(neng)的驗證(zheng)(zheng),可(ke)通過驗證(zheng)(zheng)其驅(qu)動(dong)(dong)效(xiao)(xiao)率(lv)和數(shu)字(zi)式(shi)(shi)(shi)LED輸(shu)出(chu)(chu)特性(xing)實現(xian)。驅(qu)動(dong)(dong)效(xiao)(xiao)率(lv)是影響(xiang)數(shu)字(zi)式(shi)(shi)(shi)LED光(guang)效(xiao)(xiao)的最主要原(yuan)因,通過數(shu)字(zi)式(shi)(shi)(shi)LED輸(shu)出(chu)(chu)特性(xing)數(shu)據則能(neng)夠(gou)看出(chu)(chu)數(shu)字(zi)式(shi)(shi)(shi)LED電(dian)(dian)源(yuan)驅(qu)動(dong)(dong)設(she)計(ji)的成功(gong)與否。

實(shi)驗對(dui)6種不同規格(ge)的數字(zi)式(shi)LED進(jin)行(xing)驅(qu)(qu)動(dong),先(xian)利(li)用萬用表對(dui)本文(wen)數字(zi)式(shi)LED驅(qu)(qu)動(dong)電源(yuan)驅(qu)(qu)動(dong)中整流濾波后(hou)的電壓進(jin)行(xing)了測量,隨(sui)后(hou)將C8051F021芯(xin)片的輸出信號頻(pin)率調至30 kHz,并利(li)用特定電源(yuan)為C8051F021芯(xin)片供電。實(shi)驗室的溫(wen)度恒定在20 ℃,濕(shi)度控制較為嚴格(ge),此時(shi)的驅(qu)(qu)動(dong)效率曲線如圖6所示(shi),數字(zi)式(shi)LED輸出特性如表1所示(shi)。

由圖(tu)6、表1可知,本文(wen)所設計的(de)數(shu)字(zi)式(shi)(shi)LED驅(qu)(qu)(qu)動(dong)(dong)電(dian)源(yuan)的(de)驅(qu)(qu)(qu)動(dong)(dong)效(xiao)率維持在89%左右,而市面上的(de)數(shu)字(zi)式(shi)(shi)LED驅(qu)(qu)(qu)動(dong)(dong)電(dian)源(yuan)的(de)驅(qu)(qu)(qu)動(dong)(dong)效(xiao)率一(yi)般為(wei)80%;在數(shu)字(zi)式(shi)(shi)LED輸出特性統計表中,實際輸出的(de)電(dian)流和電(dian)壕在正常范圍內波動(dong)(dong),且電(dian)流變化對(dui)電(dian)壓(ya)輸出的(de)影響不大。當電(dian)流小于300 mA時,數(shu)字(zi)式(shi)(shi)LED驅(qu)(qu)(qu)動(dong)(dong)電(dian)源(yuan)會停止對(dui)數(shu)字(zi)式(shi)(shi)LED進(jin)行驅(qu)(qu)(qu)動(dong)(dong)。以上結果能夠證明,基于嵌(qian)入式(shi)(shi)系統的(de)動(dong)(dong)態光調節(jie)下數(shu)字(zi)式(shi)(shi)LED驅(qu)(qu)(qu)動(dong)(dong)電(dian)源(yuan)的(de)驅(qu)(qu)(qu)動(dong)(dong)性能較強。

3.2 電源轉換效(xiao)率驗證

對本(ben)文設計(ji)的(de)基于(yu)嵌入(ru)式(shi)系統的(de)動(dong)態光調節下數(shu)字式(shi)LED驅動(dong)電源的(de)電源轉(zhuan)換效率(lv)進行驗證,其結果(guo)如(ru)圖7所(suo)示。

由圖7可知(zhi),本(ben)文所設計(ji)的(de)(de)數(shu)字(zi)式(shi)LED驅(qu)(qu)動(dong)電源的(de)(de)電源轉(zhuan)換效(xiao)率(lv)范圍在[80%,88%]之間,且波(bo)動(dong)較為穩定,未產生(sheng)尖(jian)峰脈沖(chong)現(xian)象,可見(jian)其對數(shu)字(zi)式(shi)LED功率(lv)的(de)(de)矯正水(shui)平較高,能夠實(shi)現(xian)動(dong)態光對數(shu)字(zi)式(shi)LED的(de)(de)有(you)效(xiao)調節,驗證了基于嵌入式(shi)系統的(de)(de)動(dong)態光調節下(xia)數(shu)字(zi)式(shi)LED驅(qu)(qu)動(dong)電源的(de)(de)電源轉(zhuan)換效(xiao)率(lv)較高。

4 結 論

本文設計(ji)基(ji)于(yu)(yu)嵌(qian)(qian)入(ru)式系(xi)統的(de)動(dong)態(tai)光調節(jie)下(xia)數(shu)(shu)字式LED驅(qu)(qu)動(dong)電(dian)(dian)(dian)源。其(qi)中(zhong)的(de)A/D采(cai)(cai)集模塊對(dui)動(dong)態(tai)光調節(jie)下(xia)的(de)數(shu)(shu)字式LED數(shu)(shu)據(ju)進(jin)行(xing)采(cai)(cai)集、整流(liu)、濾波和A/D轉換,得到A/D采(cai)(cai)樣數(shu)(shu)據(ju)并傳輸到驅(qu)(qu)動(dong)電(dian)(dian)(dian)路。驅(qu)(qu)動(dong)電(dian)(dian)(dian)路采(cai)(cai)用(yong)嵌(qian)(qian)入(ru)式設計(ji)對(dui)A/D采(cai)(cai)樣數(shu)(shu)據(ju)進(jin)行(xing)優化(hua),進(jin)而實現對(dui)LED發(fa)光的(de)合理(li)控制和動(dong)態(tai)光對(dui)數(shu)(shu)字式LED的(de)有(you)效(xiao)調節(jie)。C8051F021芯片是基(ji)于(yu)(yu)嵌(qian)(qian)入(ru)式系(xi)統的(de)動(dong)態(tai)光調節(jie)下(xia)數(shu)(shu)字式LED驅(qu)(qu)動(dong)電(dian)(dian)(dian)源的(de)“管理(li)者”,其(qi)管理(li)流(liu)程圖于(yu)(yu)軟(ruan)件中(zhong)給出。軟(ruan)件還(huan)對(dui)A/D采(cai)(cai)集模塊的(de)數(shu)(shu)據(ju)采(cai)(cai)集語言(yan)進(jin)行(xing)了設計(ji)。實驗結果表明,所設計(ji)的(de)數(shu)(shu)字式LED驅(qu)(qu)動(dong)電(dian)(dian)(dian)源驅(qu)(qu)動(dong)性能強、電(dian)(dian)(dian)源轉換效(xiao)率高。

參考文獻

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[4] 汪(wang)飛,鐘(zhong)元旭,阮(ruan)毅.AC?DC LED驅動電源消(xiao)除電解電容技術(shu)綜述[J].電工技術(shu)學報,2015,30(8):176?185.

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[6] 徐超,張淼.基于LLC諧振的大功率LED驅動電源的研究[J].電力電子(zi)技術(shu),2014,48(5):42?44.

篇7

關鍵詞:電梯;振動;噪音;解決對策

中圖(tu)分類號:TU857 文獻標識碼:A

隨著電(dian)(dian)(dian)梯技術(shu)的革新和(he)城市規(gui)模集中化,現(xian)代電(dian)(dian)(dian)梯的運(yun)行(xing)速度及提升(sheng)高(gao)度都(dou)在快速提升(sheng)。上海某高(gao)層建筑(zhu)的電(dian)(dian)(dian)梯速度達到18m/s,總高(gao)度超過(guo)500m。高(gao)層高(gao)速的電(dian)(dian)(dian)梯隱藏著安全(quan)風險隱患(huan)和(he)振動(dong)(dong)、噪音等負(fu)面(mian)問題,振動(dong)(dong)和(he)噪音恰是被(bei)人體直接感受到的運(yun)行(xing)舒適(shi)性指標。曳引(yin)驅動(dong)(dong)電(dian)(dian)(dian)梯由(you)于(yu)提升(sheng)高(gao)度大、速度高(gao)和(he)簡(jian)單、可靠(kao)等優(you)點而(er)被(bei)廣泛應(ying)用于(yu)各種建筑(zhu),目(mu)前(qian)我國大部分(fen)電(dian)(dian)(dian)梯為曳引(yin)式驅動(dong)(dong)方式,本文(wen)僅討(tao)論此類電(dian)(dian)(dian)梯。

國家標準GB/T10058-2009《電梯技術條件》中第3.3.5 項要求(qiu):“乘客(ke)電梯轎廂運(yun)行在恒(heng)加速度區域內的垂(chui)直(zhi)(Z軸(zhou))振動的最大峰(feng)峰(feng)值不應(ying)大于(yu)(yu)(yu)0.30m/s2,A95峰(feng)峰(feng)值不應(ying)大于(yu)(yu)(yu)0.20m/s2。乘客(ke)電梯轎廂運(yun)行期間水平(X軸(zhou)和Y軸(zhou))振動的最大峰(feng)峰(feng)值不應(ying)大于(yu)(yu)(yu)0.20 m/s2,A95峰(feng)峰(feng)值不應(ying)大于(yu)(yu)(yu)0.15m/s2”。

《電梯技術條件》中(zhong)第3.3.6項要(yao)求見表1。

研(yan)究表明(ming),人(ren)體垂(chui)直方向上(shang)在4Hz-8Hz存在一個可引(yin)起胸腔(qiang)共(gong)(gong)振(zhen)(zhen)的最大(da)共(gong)(gong)振(zhen)(zhen)區(qu)(qu),對胸腔(qiang)內(nei)器官(guan)(guan)危(wei)害最大(da);在10Hz 附近(jin)另有一個可引(yin)起腹(fu)腔(qiang)共(gong)(gong)振(zhen)(zhen)的小共(gong)(gong)振(zhen)(zhen)峰區(qu)(qu),對腹(fu)部內(nei)器官(guan)(guan)危(wei)害大(da)。而(er)人(ren)體對水(shui)平振(zhen)(zhen)動(dong)的敏感(gan)(gan)度(du)(du)(du)比垂(chui)直振(zhen)(zhen)動(dong)高,1Hz-2Hz的水(shui)平振(zhen)(zhen)動(dong)影響尤為明(ming)顯(xian)。電(dian)梯(ti)(ti)由于機(ji)械聯接、電(dian)氣控制、乘客重心分(fen)布等因(yin)素相互作用(yong),產生振(zhen)(zhen)動(dong)、加(jia)(jia)(jia)速(su)(su)度(du)(du)(du)、噪(zao)音(yin)(yin)問題。人(ren)體對于加(jia)(jia)(jia)速(su)(su)度(du)(du)(du)、振(zhen)(zhen)動(dong)和噪(zao)音(yin)(yin)的感(gan)(gan)受極其敏感(gan)(gan),電(dian)梯(ti)(ti)的舒(shu)適(shi)性主要以(yi)加(jia)(jia)(jia)減(jian)速(su)(su)度(du)(du)(du)、加(jia)(jia)(jia)速(su)(su)度(du)(du)(du)變化率、振(zhen)(zhen)動(dong)頻(pin)率及噪(zao)音(yin)(yin)等為參(can)考指標。電(dian)梯(ti)(ti)起動(dong)/制停過(guo)程加(jia)(jia)(jia)速(su)(su)度(du)(du)(du)(或變化率)大(da)或振(zhen)(zhen)動(dong)加(jia)(jia)(jia)速(su)(su)度(du)(du)(du)大(da)、振(zhen)(zhen)動(dong)頻(pin)率在人(ren)體的共(gong)(gong)振(zhen)(zhen)區(qu)(qu)內(nei),人(ren)體會有頭暈、惡心、心慌(huang)甚至休克(ke)。因(yin)此,有必要通過(guo)分(fen)析(xi)電(dian)梯(ti)(ti)振(zhen)(zhen)動(dong)和噪(zao)音(yin)(yin)產生原因(yin),采用(yong)科學(xue)手段,抑制電(dian)梯(ti)(ti)運(yun)(yun)行振(zhen)(zhen)動(dong)和降低運(yun)(yun)行噪(zao)音(yin)(yin),提(ti)高電(dian)梯(ti)(ti)乘坐舒(shu)適(shi)感(gan)(gan),也為安裝、維保、檢驗工作提(ti)供(gong)參(can)考。

1 振動和噪音的(de)來源分析及(ji)相應解決對(dui)策

電梯是(shi)機械和(he)電氣組合的機電產品(pin)。從(cong)設(she)計(ji)、安裝(zhuang)到調試(shi)、日常保養過程入手,電梯的振動和(he)噪音(yin)是(shi)可采取措施給予(yu)消除或降低的。

1.1 導(dao)軌的安裝(zhuang)質量

導(dao)(dao)軌(gui)(gui)(gui)的(de)安(an)裝(zhuang)質量包(bao)括強度(du)(du)(du)(du)與(yu)剛度(du)(du)(du)(du),工作表面粗糙(cao)度(du)(du)(du)(du)和垂直度(du)(du)(du)(du)、平(ping)行(xing)度(du)(du)(du)(du)以及軌(gui)(gui)(gui)距偏(pian)差(cha)(cha)(cha)、接頭臺階高(gao)度(du)(du)(du)(du)差(cha)(cha)(cha)等(deng),其中導(dao)(dao)軌(gui)(gui)(gui)的(de)強度(du)(du)(du)(du)、剛度(du)(du)(du)(du)、垂直度(du)(du)(du)(du)、平(ping)行(xing)度(du)(du)(du)(du)等(deng)與(yu)安(an)裝(zhuang)狀況(kuang)關系尤為密(mi)切。井道土建(jian)圈梁的(de)質量、垂直偏(pian)差(cha)(cha)(cha)、設(she)置(zhi)間距,或鋼構井道的(de)聯接固定質量、精度(du)(du)(du)(du)都(dou)直接影(ying)響(xiang)導(dao)(dao)軌(gui)(gui)(gui)的(de)剛度(du)(du)(du)(du)(尤其高(gao)速重載、偏(pian)載等(deng)不利情形)。安(an)裝(zhuang)過程的(de)缺陷,如導(dao)(dao)軌(gui)(gui)(gui)對(dui)中誤(wu)差(cha)(cha)(cha)、垂直度(du)(du)(du)(du)誤(wu)差(cha)(cha)(cha)、導(dao)(dao)軌(gui)(gui)(gui)接頭臺階高(gao)度(du)(du)(du)(du)差(cha)(cha)(cha)、軌(gui)(gui)(gui)距偏(pian)差(cha)(cha)(cha)過大、導(dao)(dao)軌(gui)(gui)(gui)支架松(song)動等(deng),均會引起電梯轎廂垂直、水(shui)平(ping)振動,且運行(xing)速度(du)(du)(du)(du)越快,影(ying)響(xiang)越明顯。

嚴(yan)格施(shi)工,定(ding)好(hao)基準樣線,避免(mian)導(dao)軌軌距(ju)(ju)、垂(chui)直度與平(ping)行度等背離設計要求值,安(an)裝后,驗證(zheng)確認,如用(yong)校軌尺校正軌距(ju)(ju)、用(yong)激光校準儀(yi)器校正導(dao)軌垂(chui)直度和平(ping)行度等。對土(tu)建(jian)(jian)部分,重點做(zuo)好(hao)土(tu)建(jian)(jian)驗收確認(支撐間距(ju)(ju)和施(shi)工質量(liang)等),高(gao)強度螺栓要用(yong)扭矩扳手預緊和其他螺栓要有防松措施(shi)。

1.2 曳引機的安裝質量(liang)

曳(ye)(ye)引(yin)機自(zi)身的(de)缺(que)陷或者(zhe)安(an)裝質量等(deng)產生的(de)振(zhen)動(dong)(dong)和(he)噪音,會通(tong)過曳(ye)(ye)引(yin)鋼(gang)絲繩或者(zhe)扁平鋼(gang)帶傳遞給轎廂(xiang)。電動(dong)(dong)機-減速箱-曳(ye)(ye)引(yin)機的(de)機座(zuo)或者(zhe)永磁同(tong)步曳(ye)(ye)引(yin)機的(de)機座(zuo)安(an)裝了性能優良的(de)減振(zhen)墊/緩沖(chong)墊等(deng)從設(she)計(ji)上降低(di)了運轉振(zhen)動(dong)(dong)與噪音。

驅動主機機座與(yu)承重(zhong)工(gong)字(zi)(zi)鋼(gang)的(de)固(gu)定以及該(gai)工(gong)字(zi)(zi)鋼(gang)與(yu)土建承重(zhong)墩的(de)固(gu)定是否(fou)牢靠(kao),工(gong)字(zi)(zi)鋼(gang)承重(zhong)梁的(de)水(shui)平度與(yu)剛度等(deng)等(deng)因素都有可(ke)能增(zeng)加或(huo)者(zhe)放大(da)曳(ye)引(yin)機運轉(zhuan)時(shi)的(de)振(zhen)動與(yu)噪音。當(dang)機座與(yu)承重(zhong)工(gong)字(zi)(zi)鋼(gang)組(zu)合體或(huo)者(zhe)轎(jiao)廂的(de)某幾階(jie)固(gu)有頻率與(yu)驅動主機的(de)轉(zhuan)動頻率接近時(shi),會產(chan)生共振(zhen)。安裝后(hou)的(de)檢測評(ping)估,通(tong)過載(zai)荷試驗檢驗曳(ye)引(yin)性(xing)能和(he)測量振(zhen)動、加減(jian)速(su)、噪音等(deng)數據,根據檢測結(jie)果調整參(can)數,避開共振(zhen)區(qu)。

1.3 曳引鋼絲繩或者扁平鋼帶組合(he)的(de)安裝質量

曳引鋼絲繩組(zu)合(he)或(huo)者(zhe)(zhe)曳引扁(bian)平鋼帶組(zu)合(he)等(deng)稱(cheng)為柔性懸掛連接裝(zhuang)置(zhi),在理想(xiang)狀態下,每(mei)根鋼絲繩或(huo)者(zhe)(zhe)扁(bian)平鋼帶應均(jun)勻受(shou)力,張(zhang)緊力一致(zhi)或(huo)者(zhe)(zhe)相(xiang)差很小,繩頭組(zu)合(he)的(de)減振彈簧剛度一致(zhi),否(fou)則,由于懸掛裝(zhuang)置(zhi)的(de)受(shou)力不均(jun),將會(hui)產生劇烈的(de)晃(huang)振現(xian)象,導致(zhi)轎廂振動和(he)噪音加劇。

安裝調試時,調整(zheng)懸(xuan)掛繩(sheng)(sheng)張緊度一致;例(li)行保養應注意(yi)檢(jian)查調整(zheng)懸(xuan)掛繩(sheng)(sheng)的張緊度。

1.4 電(dian)梯起動(dong)/制(zhi)停運行(xing)過程的加減(jian)速沖擊(ji)負荷(he)

電梯(ti)的工作(zuo)(zuo)特點是頻(pin)繁的起動(dong)(dong)和制停,在這些過程中,柔性(xing)懸掛(gua)裝(zhuang)置(zhi)除了承受轎廂、對重、轎廂內載(zai)(zai)(zai)荷等靜載(zai)(zai)(zai)荷外,還承受加減速(su)產生的慣(guan)性(xing)載(zai)(zai)(zai)荷。由于柔性(xing)懸掛(gua)裝(zhuang)置(zhi)的自身彈性(xing)作(zuo)(zuo)用,電梯(ti)系統中會出現按一定頻(pin)率變化的振動(dong)(dong)載(zai)(zai)(zai)荷,慣(guan)性(xing)載(zai)(zai)(zai)荷與振動(dong)(dong)載(zai)(zai)(zai)荷組合而(er)成(cheng)的動(dong)(dong)載(zai)(zai)(zai)荷,會使柔性(xing)懸掛(gua)裝(zhuang)置(zhi)出現抖(dou)動(dong)(dong)現象,進而(er)導致轎廂出現抖(dou)動(dong)(dong)現象。

電梯安(an)裝后自動按程序選(xuan)擇最佳運行(xing)(xing)曲線運行(xing)(xing),由于安(an)裝現場情況不同,電梯公司應選(xuan)派(pai)調試(shi)員到場根據實際(ji)的運行(xing)(xing)狀(zhuang)況進行(xing)(xing)細調,避免運行(xing)(xing)過(guo)程的加減速(su)沖擊負荷超過(guo)設計要(yao)求(qiu)。

1.5 井道內的(de)氣流和建筑物自振對電梯系統的(de)激勵作(zuo)用

運行(xing)速(su)(su)度越高(gao)(gao)的電梯井(jing)道(dao)(dao)中會產生(sheng)不(bu)可忽視的“活(huo)塞效(xiao)應”,產生(sheng)的振動噪(zao)音隨著運行(xing)速(su)(su)度的提高(gao)(gao)而成正(zheng)比增加。高(gao)(gao)層高(gao)(gao)速(su)(su)電梯一(yi)(yi)般采用(yong)(yong)共(gong)用(yong)(yong)井(jing)道(dao)(dao),借助于共(gong)通(tong)井(jing)道(dao)(dao),增大井(jing)道(dao)(dao)內空(kong)(kong)(kong)氣(qi)的快(kuai)速(su)(su)疏散通(tong)道(dao)(dao),減輕轎廂高(gao)(gao)速(su)(su)運行(xing)時井(jing)道(dao)(dao)內空(kong)(kong)(kong)氣(qi)一(yi)(yi)端被急劇壓縮,另一(yi)(yi)端被迅(xun)速(su)(su)抽空(kong)(kong)(kong)而出現轎廂運行(xing)受阻和瑞流激(ji)振,導致轎廂和柔性懸掛裝置(zhi)劇烈振動。有的還在機房地(di)面(mian)和底坑(keng)側面(mian)設置(zhi)減壓孔(kong),以利于進一(yi)(yi)步(bu)消除井(jing)道(dao)(dao)高(gao)(gao)速(su)(su)氣(qi)流對電梯的激(ji)振激(ji)勵。

1.6 轎(jiao)廂壁板(ban)(ban)、護腳板(ban)(ban)、防護板(ban)(ban)等薄板(ban)(ban)固定質量

轎廂與(yu)層門以及(ji)護腳板和井道內表面(mian)防護板的薄板結構是振動與(yu)噪音產(chan)(chan)生(sheng)的激(ji)發源。如果薄板固定不(bu)牢靠導致剛度不(bu)足,轎廂高(gao)速運(yun)行時(shi)產(chan)(chan)生(sheng)的高(gao)速氣流激(ji)振薄板會(hui)產(chan)(chan)生(sheng)很大(da)的運(yun)行振動與(yu)噪音,進而來(lai)回(hui)反(fan)射傳遞(di)到(dao)轎廂內。

1.7 補(bu)償繩/補(bu)償鏈的(de)安(an)裝(zhuang)質(zhi)量

大提升(sheng)高度的電梯,當(dang)轎廂(xiang)處(chu)于(yu)(yu)最(zui)低(di)和(he)最(zui)高層站時,由于(yu)(yu)轎廂(xiang)與對重(zhong)側(ce)曳引繩(sheng)的重(zhong)量(liang)差大導(dao)致兩側(ce)重(zhong)量(liang)不平衡,破壞曳引性能,增加(jia)運行(xing)不平穩(wen),加(jia)劇(ju)振(zhen)動和(he)噪音。注(zhu)意補償繩(sheng)/鏈的安裝(zhuang)位置,確保(bao)與轎底(di)隨行(xing)電纜及配(pei)重(zhong)塊在安裝(zhuang)后(hou)保(bao)持(chi)平衡,做好防松防扭,避免(mian)運行(xing)扭振(zhen)。

1.8 測速回饋(kui)信號的因素

在電梯測速閉環回路中,測速信號不正確或者(zhe)不穩定(ding),會造成(cheng)控制輸(shu)出(chu)信號的不正常甚至是紊(wen)亂,系統振蕩,乃至于出(chu)現機械系統的共振。

避免(mian)以下這些情(qing)形:旋轉(zhuan)編碼器不(bu)可靠、偏移、不(bu)對(dui)中等(deng);旋轉(zhuan)編碼器變形、卡阻(zu)等(deng);旋轉(zhuan)編碼器輸(shu)出信號(hao)的屏(ping)蔽線未接而遭受干擾等(deng),引起饋送信號(hao)失常。

1.9 供電(dian)系統的電(dian)壓問題

電(dian)壓過(guo)高或者(zhe)過(guo)低(波動應在±7%額定值內)、三(san)相電(dian)壓不平衡等會(hui)造成電(dian)動機產生(sheng)諧波力矩產生(sheng)脈動振(zhen)動并(bing)通過(guo)柔性懸(xuan)掛裝置(zhi)傳遞(di)給(gei)轎(jiao)廂(xiang),加(jia)劇振(zhen)動與噪音。

使用(yong)符(fu)合相(xiang)應電流額(e)定值的電纜供電,電源從(cong)供電箱直(zhi)接引接,主電源開關后不接其(qi)他(ta)用(yong)電設備。

2 工程實例應用

某(mou)住宅電梯:額(e)定載荷(he)1000kg,額(e)定速度1.75m/s,18層18站18門,為蝸輪蝸桿減速箱的曳引式客梯。

問題描述:電(dian)梯(ti)(ti)在上(shang)下運行(xing)時(shi),1-14層之間的(de)(de)(de)電(dian)梯(ti)(ti)井(jing)道周圍的(de)(de)(de)套房各房間沒有明顯可(ke)辨的(de)(de)(de)主機運行(xing)噪音(yin)(yin),但到了15層往上(shang)的(de)(de)(de)各個樓層,電(dian)梯(ti)(ti)運行(xing)時(shi),與(yu)電(dian)梯(ti)(ti)井(jing)道壁相(xiang)鄰的(de)(de)(de)房間里有明顯的(de)(de)(de)“嗡嗡嗡”噪音(yin)(yin),越(yue)往高的(de)(de)(de)樓層,與(yu)井(jing)道壁相(xiang)鄰的(de)(de)(de)套房房間墻壁周圍的(de)(de)(de)噪音(yin)(yin)測(ce)量(liang)值(zhi)(zhi)越(yue)大(da)(da)。經現場測(ce)量(liang),電(dian)梯(ti)(ti)運行(xing)時(shi)機房內(nei)和(he)轎廂(xiang)內(nei)的(de)(de)(de)噪音(yin)(yin)值(zhi)(zhi)分(fen)(fen)(fen)別為(wei)74dB(A)和(he)52 dB(A)。測(ce)量(liang)轎廂(xiang)內(nei)X軸和(he)Y軸振動的(de)(de)(de)最(zui)大(da)(da)峰(feng)值(zhi)(zhi)和(he)A95峰(feng)值(zhi)(zhi)分(fen)(fen)(fen)別為(wei)0.18m/s2和(he)0.13 m/s2,而Z軸振動的(de)(de)(de)最(zui)大(da)(da)峰(feng)值(zhi)(zhi)和(he)A95峰(feng)值(zhi)(zhi)分(fen)(fen)(fen)別為(wei)0.25m/s2和(he)0.16m/s2。

經檢查,發現驅動(dong)主機機座下的(de)兩根(gen)承重梁(工(gong)字鋼(gang))橫(heng)向水(shui)平(ping)度誤差約2.5mm,縱向水(shui)平(ping)度誤差小(xiao)于0.5/1000。曳(ye)(ye)引(yin)輪的(de)垂直度誤差,空(kong)載時(shi),曳(ye)(ye)引(yin)輪向外側偏斜0.5mm,滿載時(shi),該偏斜量達3mm。主機機座的(de)減(jian)振橡膠(jiao)墊(dian)存(cun)在(zai)老化龜裂現象。

檢查發現(xian),工字(zi)鋼(gang)(gang)承重(zhong)梁(liang)下方(fang)的(de)槽(cao)鋼(gang)(gang)在二次回填混(hun)凝土(tu)時并未完全填實,致(zhi)使(shi)工字(zi)鋼(gang)(gang)下方(fang)的(de)槽(cao)鋼(gang)(gang)內(nei)存(cun)在一個空腔,當驅動(dong)主(zhu)(zhu)機(ji)及其(qi)機(ji)座和承重(zhong)工字(zi)鋼(gang)(gang)的(de)振(zhen)(zhen)動(dong)頻率與土(tu)建(jian)承重(zhong)墩(dun)的(de)固有頻率接近時,由于槽(cao)鋼(gang)(gang)內(nei)空腔具有類似共鳴箱作用,驅動(dong)主(zhu)(zhu)機(ji)的(de)振(zhen)(zhen)動(dong)及噪音就得到加強(qiang),并通過井道的(de)土(tu)建(jian)梁(liang)傳遞(di)給(gei)靠近電梯機(ji)房的(de)各個樓層的(de)房間,所以電梯運(yun)行時最上幾個樓層與井道相鄰(lin)的(de)房間振(zhen)(zhen)動(dong)和噪音表現(xian)明顯。

處理措施:更換老化的(de)(de)(de)減振(zhen)橡(xiang)膠(jiao)墊(dian),并(bing)再加(jia)裝一組高性(xing)能減振(zhen)復(fu)合材料,通過加(jia)裝墊(dian)片降(jiang)低(di)主機(ji)(ji)機(ji)(ji)座的(de)(de)(de)橫向水平誤(wu)差,將該誤(wu)差減至0.5mm以(yi)內(nei),消(xiao)除(chu)鋼絲繩在曳引輪(lun)槽(cao)(cao)壁上(shang)周(zhou)期(qi)性(xing)斜(xie)滑入輪(lun)槽(cao)(cao)產生的(de)(de)(de)沖(chong)擊。重(zhong)新(xin)填充主機(ji)(ji)工(gong)字鋼承重(zhong)梁與(yu)混凝土承重(zhong)墩上(shang)槽(cao)(cao)鋼內(nei)的(de)(de)(de)空(kong)腔(qiang),消(xiao)除(chu)空(kong)腔(qiang)產生類似(si)共(gong)鳴箱作用而增強運行噪(zao)音。改進后(hou)檢測,電梯運行時機(ji)(ji)房內(nei)和(he)(he)轎廂(xiang)內(nei)的(de)(de)(de)噪(zao)音值(zhi)(zhi)分別(bie)為70dB(A)和(he)(he)50dB(A)。測量轎廂(xiang)內(nei)X軸和(he)(he)Y軸振(zhen)動的(de)(de)(de)最大峰值(zhi)(zhi)和(he)(he)A95峰值(zhi)(zhi)分別(bie)為0.15m/s2和(he)(he)0.11 m/s2,而Z軸振(zhen)動的(de)(de)(de)最大峰值(zhi)(zhi)和(he)(he)A95峰值(zhi)(zhi)分別(bie)為0.18m/s2和(he)(he)0.12m/s2。運行時,最高幾個(ge)(ge)樓(lou)層(ceng)與(yu)井道相鄰的(de)(de)(de)各個(ge)(ge)房間內(nei)“嗡(weng)嗡(weng)嗡(weng)”聲明(ming)顯降(jiang)低(di),人(ren)體不舒適感(gan)明(ming)顯減輕。由此(ci)可判定(ding)這些措施的(de)(de)(de)減振(zhen)降(jiang)噪(zao)效果明(ming)顯(圖1)。

結語

本文(wen)通過對電梯(ti)振(zhen)動(dong)和噪(zao)(zao)音(yin)產生的(de)(de)(de)(de)潛在源(yuan)進行(xing)分析討論,并提出相(xiang)應的(de)(de)(de)(de)部分可(ke)(ke)行(xing)處(chu)理意見,為電梯(ti)的(de)(de)(de)(de)安裝、維保(bao)、檢(jian)驗等過程中可(ke)(ke)能遇(yu)到(dao)的(de)(de)(de)(de)問(wen)題提供參考借鑒。安裝調(diao)試的(de)(de)(de)(de)整體質(zhi)量對電梯(ti)整個壽命(ming)周期的(de)(de)(de)(de)舒適感有(you)著直(zhi)接和持續的(de)(de)(de)(de)影響,更(geng)應加以(yi)重(zhong)視。對于電梯(ti)的(de)(de)(de)(de)振(zhen)動(dong)源(yuan)和噪(zao)(zao)音(yin)源(yuan)進行(xing)討論分析,采取(qu)合理措施加以(yi)控制,是可(ke)(ke)以(yi)有(you)效(xiao)改善乘坐舒適感的(de)(de)(de)(de)。

參考文獻

[1]劉希花.曳(ye)引電梯機械振動系統的固有特性與動力學響(xiang)應[D].山(shan)東:山(shan)東大(da)學,2010.

篇8

[關(guan)鍵詞(ci)]車窗電(dian)機(ji)結(jie)構及原理設計(ji) 定子 轉子 電(dian)刷板 齒輪(lun)箱等4部分結(jie)構 設計(ji)及生產 及未來車窗電(dian)機(ji)發展方向

中(zhong)圖分類號(hao):TP302 文獻標識碼:A 文章編(bian)號(hao):1009-914X(2015)34-0043-02

1 汽車(che)天(tian)窗驅動(dong)電機結構及原理(li)設計

一般(ban)汽(qi)車(che)(che)在行駛(shi)時(shi)若車(che)(che)內(nei)(nei)(nei)無新(xin)鮮空(kong)氣補充,就會使空(kong)氣中二氧(yang)化碳(tan)量增加(jia)、氧(yang)氣量降(jiang)低引(yin)起(qi)其(qi)(qi)(qi)大腦缺氧(yang),產生疲勞(lao)困倦的(de)(de)(de)感(gan)覺(jue)。雖然有時(shi)候駕乘者會通(tong)過(guo)側(ce)窗(chuang)進行換氣,但(dan)是側(ce)窗(chuang)打(da)開(kai)后,吹到(dao)人們身上的(de)(de)(de)漩渦氣流會讓架乘著感(gan)覺(jue)風很大,又(you)由(you)于其(qi)(qi)(qi)上部(bu)的(de)(de)(de)不通(tong)風,車(che)(che)內(nei)(nei)(nei)也會產生巨大的(de)(de)(de)噪音,引(yin)起(qi)其(qi)(qi)(qi)耳鳴分(fen)散其(qi)(qi)(qi)注意(yi)力,最終導致(zhi)無法安全(quan)行車(che)(che)的(de)(de)(de)后果。特別是駕乘者在高速行駛(shi)時(shi)風帶(dai)著灰塵(chen)等雜質直接沖撞(zhuang)到(dao)司(si)(si)機身上,更容易降(jiang)低駕駛(shi)者的(de)(de)(de)舒適感(gan)和注意(yi)力,引(yin)起(qi)事故。因此現在汽(qi)車(che)(che)多采(cai)取車(che)(che)內(nei)(nei)(nei)加(jia)裝天窗(chuang)的(de)(de)(de)設計(ji),既改善司(si)(si)機駕駛(shi)的(de)(de)(de)安全(quan)性,又(you)能通(tong)過(guo)天窗(chuang)玻(bo)璃的(de)(de)(de)自然采(cai)光(guang)給車(che)(che)室內(nei)(nei)(nei)營造(zao)出光(guang)明(ming)浪漫的(de)(de)(de)氣氛。

驅動(dong)車(che)窗(chuang)(chuang)(chuang)的工作(zuo)(zuo)是一項間斷性工作(zuo)(zuo),作(zuo)(zuo)為核心部件的驅動(dong)電(dian)機(ji)(ji)在其(qi)傳(chuan)動(dong)機(ji)(ji)構運行過程中起(qi)著(zhu)非常重要的作(zuo)(zuo)用。其(qi)通(tong)過電(dian)機(ji)(ji)的轉速(su)及電(dian)流變化自由的驅動(dong)車(che)窗(chuang)(chuang)(chuang)玻璃沿滑槽前后(hou)移動(dong)、傾斜啟閉。伴隨著(zhu)ECU科技的迅速(su)發展,實現車(che)窗(chuang)(chuang)(chuang)遠程精準停留功能也(ye)成為易事。本設計的驅動(dong)電(dian)機(ji)(ji)就是配合天窗(chuang)(chuang)(chuang)ECU設計的一款直流永磁(ci)帶傳(chuan)感的有刷電(dian)機(ji)(ji)。

它是(shi)一(yi)種機械(xie)能(neng)與電(dian)能(neng)相互(hu)轉(zhuan)(zhuan)換的強(qiang)驅(qu)動(dong)裝置,其在整(zheng)個運(yun)行(xing)過程(cheng)中實現了電(dian)能(neng)產(chan)生(sheng)、變換、傳輸、分配、使用、控制等循環作(zuo)用。根(gen)據載(zai)流轉(zhuan)(zhuan)子(zi)(zi)與主(zhu)磁(ci)場定子(zi)(zi)互(hu)相作(zuo)用產(chan)生(sheng)電(dian)磁(ci)扭矩帶動(dong)轉(zhuan)(zhuan)子(zi)(zi)不停旋轉(zhuan)(zhuan)最終產(chan)生(sheng)機械(xie)運(yun)動(dong)的工作(zuo)原理。將本設計電(dian)機分為定子(zi)(zi)、轉(zhuan)(zhuan)子(zi)(zi)、電(dian)刷(shua)板、齒輪驅(qu)動(dong)等四大組立部分。

整個電(dian)(dian)機像人體一樣各(ge)盡其(qi)責互(hu)相(xiang)配合,精準(zhun)完成(cheng)天(tian)窗各(ge)部分(fen)驅(qu)動要(yao)求(qiu)。首(shou)先定子(zi)作(zuo)(zuo)為(wei)“身軀(qu)”起(qi)著(zhu)主磁場和支撐轉(zhuan)子(zi)的作(zuo)(zuo)用(yong)。其(qi)次轉(zhuan)子(zi)作(zuo)(zuo)為(wei)“心(xin)臟”起(qi)著(zhu)切割(ge)磁力線(xian)產生感(gan)應(ying)電(dian)(dian)動勢實現電(dian)(dian)能與(yu)機械能之間轉(zhuan)換的作(zuo)(zuo)用(yong),而帶有ECU的電(dian)(dian)刷板作(zuo)(zuo)為(wei)“大腦”起(qi)著(zhu)連接轉(zhuan)子(zi)與(yu)外(wai)部電(dian)(dian)路的作(zuo)(zuo)用(yong),最后齒輪箱作(zuo)(zuo)為(wei)“大手”起(qi)著(zhu)調試控制天(tian)窗的運行及定位的作(zuo)(zuo)用(yong)。由于本設計為(wei)直流永磁帶傳(chuan)感(gan)的有刷電(dian)(dian)機,其(qi)工作(zuo)(zuo)原(yuan)理(li)便是所謂(wei)的弗萊明(ming)左手定則(ze)原(yuan)理(li)。

 即在磁(ci)場(chang)B[T]中,向垂直于磁(ci)場(chang)的(de)導(dao)(dao)體L[m]中通上電(dian)流為I[A]的(de)電(dian)時, 則通電(dian)導(dao)(dao)線在磁(ci)場(chang)中產生(sheng)力F[N]的(de)公式為:

F= B*L*I

 若磁場(chang)中鐵芯(xin)半徑為R[M],則在(zai)磁場(chang)中扭矩T[Nm]公式為:

T=2 *R*F=2 *R*B*L* I

若卷線匝數為(wei)Z[n],則在磁場中(zhong)整體產生扭矩T[Nm]的公式(shi)為(wei):

T=2* Z*R*B*L* I

通(tong)過力(li)與扭(niu)矩公式換算后,最終結(jie)論得出(chu)設(she)計的卷圈匝數Z、磁場(chang)B、導體長度(du)L。

電(dian)(dian)(dian)(dian)(dian)機旋(xuan)轉(zhuan)(zhuan)設計直(zhi)接影(ying)響天窗應(ying)用模(mo)式,因此第一階段先假設直(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)機的(de)(de)(de)(de)(de)(de)轉(zhuan)(zhuan)子(zi)不(bu)應(ying)用原動(dong)(dong)(dong)機拖動(dong)(dong)(dong),而是把電(dian)(dian)(dian)(dian)(dian)刷(shua)(shua)A、B接在(zai)(zai)電(dian)(dian)(dian)(dian)(dian)壓為(wei)U的(de)(de)(de)(de)(de)(de)直(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)源上(shang),讓電(dian)(dian)(dian)(dian)(dian)刷(shua)(shua)A為(wei)正電(dian)(dian)(dian)(dian)(dian)位(wei),B為(wei)負電(dian)(dian)(dian)(dian)(dian)位(wei),則在(zai)(zai)N極(ji)(ji)范(fan)圍(wei)內(nei)的(de)(de)(de)(de)(de)(de)導(dao)體ab中(zhong)的(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)(liu)是從(cong)a流(liu)(liu)(liu)(liu)(liu)(liu)向(xiang)(xiang)(xiang)(xiang)b,在(zai)(zai)S極(ji)(ji)范(fan)圍(wei)內(nei)的(de)(de)(de)(de)(de)(de)導(dao)體cd中(zhong)的(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)(liu)是從(cong)c流(liu)(liu)(liu)(liu)(liu)(liu)向(xiang)(xiang)(xiang)(xiang)d。那么根據弗萊明左手(shou)定則判斷出(chu)載流(liu)(liu)(liu)(liu)(liu)(liu)導(dao)體ab邊(bian)(bian)(bian)受(shou)(shou)(shou)的(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)磁(ci)力(li)(li)(li)的(de)(de)(de)(de)(de)(de)方(fang)(fang)向(xiang)(xiang)(xiang)(xiang)是向(xiang)(xiang)(xiang)(xiang)左,cd邊(bian)(bian)(bian)所受(shou)(shou)(shou)的(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)磁(ci)力(li)(li)(li)方(fang)(fang)向(xiang)(xiang)(xiang)(xiang)則是向(xiang)(xiang)(xiang)(xiang)右,又由于(yu)(yu)磁(ci)場是均勻(yun)的(de)(de)(de)(de)(de)(de),導(dao)體中(zhong)又流(liu)(liu)(liu)(liu)(liu)(liu)過相同的(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)(liu),所以ab邊(bian)(bian)(bian)和(he)cd邊(bian)(bian)(bian)所受(shou)(shou)(shou)電(dian)(dian)(dian)(dian)(dian)磁(ci)力(li)(li)(li)的(de)(de)(de)(de)(de)(de)大小也(ye)是相等(deng)的(de)(de)(de)(de)(de)(de),此時(shi)(shi)線(xian)圈在(zai)(zai)受(shou)(shou)(shou)到相同的(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)磁(ci)力(li)(li)(li)作(zuo)用時(shi)(shi)會按(an)逆時(shi)(shi)針方(fang)(fang)向(xiang)(xiang)(xiang)(xiang)進行轉(zhuan)(zhuan)動(dong)(dong)(dong)。第二(er)階段是當(dang)線(xian)圈轉(zhuan)(zhuan)到磁(ci)極(ji)(ji)的(de)(de)(de)(de)(de)(de)中(zhong)性面上(shang)時(shi)(shi),線(xian)圈中(zhong)的(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)(liu)和(he)電(dian)(dian)(dian)(dian)(dian)磁(ci)力(li)(li)(li)都等(deng)于(yu)(yu)零,但(dan)是由于(yu)(yu)慣性的(de)(de)(de)(de)(de)(de)作(zuo)用線(xian)圈會繼(ji)續轉(zhuan)(zhuan)動(dong)(dong)(dong)。第三階段是當(dang)線(xian)圈轉(zhuan)(zhuan)過半周(zhou)后,雖然ab與cd的(de)(de)(de)(de)(de)(de)位(wei)置調(diao)換了(le),但(dan)是由于(yu)(yu)換向(xiang)(xiang)(xiang)(xiang)片和(he)電(dian)(dian)(dian)(dian)(dian)刷(shua)(shua)的(de)(de)(de)(de)(de)(de)作(zuo)用,轉(zhuan)(zhuan)到N極(ji)(ji)下的(de)(de)(de)(de)(de)(de)cd邊(bian)(bian)(bian)中(zhong)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)(liu)方(fang)(fang)向(xiang)(xiang)(xiang)(xiang)也(ye)變(bian)了(le)(從(cong)d流(liu)(liu)(liu)(liu)(liu)(liu)向(xiang)(xiang)(xiang)(xiang)c),在(zai)(zai)S極(ji)(ji)下的(de)(de)(de)(de)(de)(de)ab邊(bian)(bian)(bian)中(zhong)的(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)(liu)方(fang)(fang)向(xiang)(xiang)(xiang)(xiang)也(ye)變(bian)了(le)(從(cong)b流(liu)(liu)(liu)(liu)(liu)(liu)向(xiang)(xiang)(xiang)(xiang)a),此時(shi)(shi)電(dian)(dian)(dian)(dian)(dian)磁(ci)力(li)(li)(li)F的(de)(de)(de)(de)(de)(de)方(fang)(fang)向(xiang)(xiang)(xiang)(xiang)仍然不(bu)會改變(bian),所以線(xian)圈仍然受(shou)(shou)(shou)力(li)(li)(li)按(an)逆時(shi)(shi)針方(fang)(fang)向(xiang)(xiang)(xiang)(xiang)轉(zhuan)(zhuan)動(dong)(dong)(dong)。可見(jian)若(ruo)N、S極(ji)(ji)范(fan)圍(wei)內(nei)的(de)(de)(de)(de)(de)(de)導(dao)體中(zhong)的(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)(liu)方(fang)(fang)向(xiang)(xiang)(xiang)(xiang)不(bu)變(bian),那么線(xian)圈兩(liang)個邊(bian)(bian)(bian)的(de)(de)(de)(de)(de)(de)受(shou)(shou)(shou)力(li)(li)(li)方(fang)(fang)向(xiang)(xiang)(xiang)(xiang)也(ye)不(bu)變(bian),這樣線(xian)圈就可以按(an)照受(shou)(shou)(shou)力(li)(li)(li)方(fang)(fang)向(xiang)(xiang)(xiang)(xiang)不(bu)停的(de)(de)(de)(de)(de)(de)旋(xuan)轉(zhuan)(zhuan)下去(qu)。

2 汽車天窗電動機定子結構及原理設計

正如(ru)上(shang)述功(gong)能(neng)描(miao)述一(yi)樣,定子作為電(dian)(dian)機(ji)(ji)的(de)“身(shen)軀”起(qi)著主磁(ci)(ci)(ci)(ci)場和(he)支撐轉子的(de)作用(yong)。一(yi)般(ban)定子結構分(fen)為永(yong)(yong)磁(ci)(ci)(ci)(ci)式(shi)(shi)和(he)勵磁(ci)(ci)(ci)(ci)式(shi)(shi)兩種,永(yong)(yong)磁(ci)(ci)(ci)(ci)式(shi)(shi)是永(yong)(yong)磁(ci)(ci)(ci)(ci)體與電(dian)(dian)樞導(dao)磁(ci)(ci)(ci)(ci)體形成(cheng)閉合(he)磁(ci)(ci)(ci)(ci)路(lu)的(de)形式(shi)(shi)。勵磁(ci)(ci)(ci)(ci)式(shi)(shi)則是在磁(ci)(ci)(ci)(ci)極上(shang)繞線圈后,在線圈通電(dian)(dian)形成(cheng)電(dian)(dian)磁(ci)(ci)(ci)(ci)鐵的(de)形式(shi)(shi)。雖(sui)然勵磁(ci)(ci)(ci)(ci)式(shi)(shi)的(de)定子有壽命(ming)長,在“空載(zai)”條(tiao)件下噪音(yin)小的(de)優(you)點,但是車(che)窗的(de)應用(yong)環(huan)境很(hen)難預測,在寒冷、大風(feng)等阻力環(huan)境中經常遇上(shang)持久負載(zai),易導(dao)致勵磁(ci)(ci)(ci)(ci)電(dian)(dian)機(ji)(ji)電(dian)(dian)氣(qi)原件燒毀引起(qi)“短路(lu)”等故障,因此天窗電(dian)(dian)機(ji)(ji)一(yi)般(ban)都選擇永(yong)(yong)磁(ci)(ci)(ci)(ci)式(shi)(shi)定子。

而永(yong)(yong)(yong)磁(ci)(ci)式(shi)(shi)定(ding)子若磁(ci)(ci)性弱或(huo)磁(ci)(ci)路未飽和時,經常(chang)會(hui)引起電(dian)(dian)流增(zeng)大(da)、溫度(du)(du)升高(gao)、噪(zao)音及振(zhen)動(dong)(dong)等不良現象。因(yin)此在成(cheng)本(ben)允許條件下,選擇鐵(tie)氧(yang)體永(yong)(yong)(yong)磁(ci)(ci)材(cai)(cai)料時,首先考(kao)慮(lv)高(gao)磁(ci)(ci)通密度(du)(du)(Br)和矯頑力(Hc)的磁(ci)(ci)性材(cai)(cai)料。其次由(you)于該(gai)電(dian)(dian)機額定(ding)轉速為(wei)40-50RPM,配(pei)合電(dian)(dian)樞鐵(tie)芯長(chang)度(du)(du)定(ding)子設計長(chang)48mmX寬(kuan)34.2mm且Br大(da)于420mT的對稱(cheng)磁(ci)(ci)瓦(wa)結(jie)(jie)構是非常(chang)合適(shi)的。定(ding)子一般(ban)由(you)機殼(ke)、永(yong)(yong)(yong)磁(ci)(ci)石、葉(xie)型(xing)彈簧等三部分組成(cheng),機殼(ke)根據客戶放(fang)置(zhi)電(dian)(dian)機的空間,應用直(zhi)徑為(wei)38mm扁圓筒(tong)結(jie)(jie)構。為(wei)了保(bao)證主(zhu)磁(ci)(ci)體磁(ci)(ci)場(chang)穩(wen)(wen)定(ding)、裝配(pei)位置(zhi)誤差小的功能(neng),設計選擇了比膠(jiao)粘式(shi)(shi)更(geng)穩(wen)(wen)定(ding)的葉(xie)型(xing)彈簧支撐式(shi)(shi)結(jie)(jie)構。以上永(yong)(yong)(yong)磁(ci)(ci)設計大(da)大(da)改善(shan)電(dian)(dian)機噪(zao)音及振(zhen)動(dong)(dong)的風險。永(yong)(yong)(yong)磁(ci)(ci)材(cai)(cai)料由(you)于材(cai)(cai)質堅硬很難進行機械加(jia)工,因(yin)而一般(ban)來說永(yong)(yong)(yong)磁(ci)(ci)式(shi)(shi)電(dian)(dian)動(dong)(dong)機的制造(zao)成(cheng)本(ben)比電(dian)(dian)磁(ci)(ci)式(shi)(shi)高(gao)。而電(dian)(dian)磁(ci)(ci)式(shi)(shi)比永(yong)(yong)(yong)磁(ci)(ci)式(shi)(shi)多了一項(xiang)激磁(ci)(ci)損耗。因(yin)此許多工業(ye)在生產(chan)線(xian)性高(gao)精度(du)(du)產(chan)品時都多應用永(yong)(yong)(yong)磁(ci)(ci)式(shi)(shi)電(dian)(dian)機。

3 汽車天窗電動機轉子結構及原(yuan)理(li)設(she)計

轉(zhuan)(zhuan)(zhuan)(zhuan)子作(zuo)(zuo)(zuo)為(wei)電(dian)(dian)機(ji)的“心(xin)臟”起著切割(ge)磁力(li)線(xian)產(chan)生感應(ying)電(dian)(dian)動(dong)勢實現電(dian)(dian)能與機(ji)械能之(zhi)間轉(zhuan)(zhuan)(zhuan)(zhuan)換的作(zuo)(zuo)(zuo)用(yong)(yong)(yong)。其主(zhu)要(yao)結構由(you)軸、鐵(tie)芯(xin)、卷線(xian)、換向(xiang)器(qi)、絕緣套筒(tong)、軸承及錐墊等七大部分組成。軸作(zuo)(zuo)(zuo)為(wei)驅動(dong)轉(zhuan)(zhuan)(zhuan)(zhuan)子旋轉(zhuan)(zhuan)(zhuan)(zhuan)核心(xin)部件,其材(cai)質應(ying)用(yong)(yong)(yong)了(le)(le)(le) SAE/AISI 1144鋼(gang)。鐵(tie)芯(xin)應(ying)用(yong)(yong)(yong)了(le)(le)(le)斜槽設計,即由(you)厚度(du)為(wei)1.0mm SPCC-SD硅鋼(gang)片上(shang)下(xia)16片依次錯開疊加槽位而(er)成的,該設計即保證了(le)(le)(le)電(dian)(dian)動(dong)機(ji)轉(zhuan)(zhuan)(zhuan)(zhuan)動(dong)均勻平穩(wen),又提高(gao)了(le)(le)(le)電(dian)(dian)機(ji)輸出功率,是現在(zai)高(gao)端(duan)電(dian)(dian)機(ji)常用(yong)(yong)(yong)的設計。換向(xiang)器(qi)通過焊接(jie)方式(shi)連接(jie)轉(zhuan)(zhuan)(zhuan)(zhuan)子鐵(tie)芯(xin)銅線(xian)與換向(xiang)器(qi)及碳刷(shua)電(dian)(dian)源(yuan)正負極導通達(da)到電(dian)(dian)機(ji)換向(xiang)的作(zuo)(zuo)(zuo)用(yong)(yong)(yong)。軸承作(zuo)(zuo)(zuo)為(wei)連接(jie)齒輪箱和(he)機(ji)殼橋梁,起著支撐和(he)運動(dong)協調作(zuo)(zuo)(zuo)用(yong)(yong)(yong)。由(you)于本設計電(dian)(dian)機(ji)要(yao)配合天窗中的ECU按指令停留在(zai)任意位置處(chu),因此在(zai)電(dian)(dian)樞轉(zhuan)(zhuan)(zhuan)(zhuan)子處(chu)特(te)別增加了(le)(le)(le)4瓣感應(ying)磁環(huan)的設計。

轉子設(she)計重點在于鐵(tie)芯的卷線(xian)(xian),它決定(ding)了電機電流方向(xiang)(xiang)及轉速、扭(niu)矩等功能參數(shu),不同(tong)的卷線(xian)(xian)會影響到客戶(hu)不同(tong)的應(ying)用效果(guo)。因此(ci)為了避(bi)免卷線(xian)(xian)時換向(xiang)(xiang)器與鐵(tie)芯之(zhi)間的誤(wu)差(cha),在設(she)計及卷線(xian)(xian)時必須首先確(que)認換向(xiang)(xiang)器與鐵(tie)芯的角度問題,只有明(ming)確(que)角度基準電機特(te)性(xing)才可以穩定(ding)。本設(she)計換向(xiang)(xiang)器角度為0°+/-1.5°,因此(ci)根據客戶(hu)的應(ying)用條件考慮(lv)后,將鐵(tie)芯槽(cao)(cao)數(shu)及換向(xiang)(xiang)器片數(shu)統一設(she)計為8槽(cao)(cao),銅(tong)線(xian)(xian)種類選(xuan)擇日立1 KMK-20E耐(nai)絕緣高(gao)等級的銅(tong)線(xian)(xian),線(xian)(xian)徑(jing)選(xuan)擇為4.75mm,其中每槽(cao)(cao)內匝數(shu)為24匝。

電機系列品種(zhong)規格(ge)繁(fan)多,其質(zhi)量水平(ping)及(ji)工藝差異對此(ci)類產品的(de)(de)影響起著至(zhi)關重(zhong)要(yao)的(de)(de)作用。從工程的(de)(de)角度本公司為保證(zheng)工程質(zhi)量,使用雙飛叉(cha)高端日式卷線(xian)(xian)機,該工藝即保證(zheng)了電樞(shu)兩側銅線(xian)(xian)快速(su)的(de)(de)進入(ru)鐵芯(xin)槽中,又能降低轉子的(de)(de)兩側不(bu)平(ping)衡量。同時(shi)為了有效的(de)(de)防止銅線(xian)(xian)與軸之間(jian)、銅線(xian)(xian)與鐵芯(xin)之間(jian)絕(jue)緣(yuan)損傷、匝間(jian)短(duan)路和絕(jue)緣(yuan)不(bu)良,斷線(xian)(xian),脫鉤(gou),反嵌,圈數差,絕(jue)緣(yuan)擊(ji)穿等故障的(de)(de)發生,選擇絕(jue)緣(yuan)涂層和絕(jue)緣(yuan)套筒雙重(zhong)保護的(de)(de)設(she)計。

4 汽車天窗電動(dong)機電刷板結構(gou)及(ji)原(yuan)理設(she)計

電刷板是(shi)電機(ji)機(ji)械固定部分(fen)和轉(zhuan)動(dong)部分(fen)之間(jian)傳遞能量或(huo)信(xin)號的裝置。其(qi)工作過(guo)(guo)(guo)程(cheng)是(shi)將外部恒(heng)定電流通過(guo)(guo)(guo)電刷輸入加載到(dao)轉(zhuan)動(dong)轉(zhuan)子上(shang),配合換(huan)向器改變(bian)電流方向維持(chi)馬達持(chi)續旋轉(zhuan)的過(guo)(guo)(guo)程(cheng)。同時它(ta)還有將大(da)軸(zhou)上(shang)的靜電荷經過(guo)(guo)(guo)電刷引(yin)入大(da)地(di)靜電的保護作用。

本設計(ji)的(de)(de)(de)(de)(de)電(dian)刷(shua)板(ban)是由M型碳刷(shua)架及(ji)(ji)(ji)(ji)端(duan)(duan)蓋(gai)、彈簧(huang)及(ji)(ji)(ji)(ji)碳刷(shua)、連接板(ban)及(ji)(ji)(ji)(ji)接地(di)片(pian)、電(dian)容及(ji)(ji)(ji)(ji)扼流線圈(quan)等四部(bu)(bu)分(fen)(fen)組(zu)成(cheng)。各(ge)部(bu)(bu)分(fen)(fen)作(zuo)用如(ru)下,M型碳刷(shua)架及(ji)(ji)(ji)(ji)端(duan)(duan)蓋(gai)部(bu)(bu)分(fen)(fen)有(you)(you)固(gu)定機(ji)(ji)(ji)械(xie)和(he)轉動(dong)的(de)(de)(de)(de)(de)作(zuo)用。彈簧(huang)及(ji)(ji)(ji)(ji)碳刷(shua)組(zu)立品(pin)有(you)(you)改變電(dian)流方向(xiang)(xiang)(xiang)與(yu)換(huan)向(xiang)(xiang)(xiang)器配(pei)合(he)對電(dian)機(ji)(ji)(ji)起換(huan)向(xiang)(xiang)(xiang)的(de)(de)(de)(de)(de)作(zuo)用。而連接板(ban)及(ji)(ji)(ji)(ji)接地(di)片(pian)則起著(zhu)電(dian)刷(shua)板(ban)輸入外部(bu)(bu)電(dian)流的(de)(de)(de)(de)(de)橋梁及(ji)(ji)(ji)(ji)靜電(dian)保護(hu)的(de)(de)(de)(de)(de)導(dao)體作(zuo)用。電(dian)容及(ji)(ji)(ji)(ji)扼流線圈(quan)部(bu)(bu)分(fen)(fen)有(you)(you)減少直流電(dian)機(ji)(ji)(ji)損耗,提(ti)高(gao)使(shi)用壽命、電(dian)機(ji)(ji)(ji)運轉穩(wen)定性以(yi)及(ji)(ji)(ji)(ji)降低直流電(dian)機(ji)(ji)(ji)的(de)(de)(de)(de)(de)噪聲和(he)電(dian)磁干擾得作(zuo)用。只有(you)(you)各(ge)部(bu)(bu)分(fen)(fen)同時有(you)(you)效而且配(pei)合(he)偏差減少時,電(dian)機(ji)(ji)(ji)才能更(geng)順(shun)暢有(you)(you)效的(de)(de)(de)(de)(de)換(huan)向(xiang)(xiang)(xiang),同時還可(ke)以(yi)有(you)(you)效地(di)減少電(dian)機(ji)(ji)(ji)刺(ci)耳的(de)(de)(de)(de)(de)電(dian)刷(shua)噪音。

電機轉動的時(shi)候,將電能通(tong)過碳刷(shua)(shua)(shua)及(ji)換(huan)向(xiang)器輸送給線圈(quan),其碳刷(shua)(shua)(shua)越長則(ze)電機使用(yong)(yong)壽命就(jiu)越長。因(yin)(yin)此本設計根據使用(yong)(yong)空間選(xuan)擇長為12±1mm SAE/AISI 1144材(cai)質的碳化物(wu)質。由于碳刷(shua)(shua)(shua)作用(yong)(yong)在換(huan)向(xiang)器表面的壓入力(li)大小直接影響馬(ma)達噪(zao)音(yin)及(ji)壽命,因(yin)(yin)此本設計通(tong)過不斷的實驗(yan)和(he)驗(yan)證將壓入力(li)設計在1.4+/-0.3N范(fan)圍內,以便調整馬(ma)達在合適的噪(zao)音(yin)水平(ping)中。最好選(xuan)擇彈(dan)簧(huang)支(zhi)撐的材(cai)質為SPCC-SD。

因為轉子滾(gun)動時,電(dian)(dian)刷始終(zhong)與(yu)換向器進行摩擦,而(er)且(qie)在換向的(de)瞬間還會產生電(dian)(dian)火花灼(zhuo)蝕(shi),所以電(dian)(dian)刷是直流電(dian)(dian)機(ji)里的(de)易損(sun)件。因此伴隨著(zhu)設(she)計(ji)經驗的(de)增多,在選擇材質(zhi)和部品(pin)配合(he)時一定要多考(kao)慮產品(pin)的(de)使用壽(shou)命、盡量通過合(he)理的(de)電(dian)(dian)路設(she)計(ji)降低電(dian)(dian)機(ji)噪聲和電(dian)(dian)磁(ci)干擾等(deng)不良影響,提高電(dian)(dian)機(ji)的(de)品(pin)質(zhi)能力。

5 汽車天(tian)窗電動(dong)機齒輪箱(xiang)結(jie)構及(ji)原(yuan)理設計

當汽車行駛速度過快時有可能造成天(tian)窗吹落,或是由于風阻產生(sheng)

汽車的耗油量增(zeng)大(da)(da),降低車速(su)(su)(su)(su)(su)等不良(liang)現象。因此(ci)(ci)天窗核心動(dong)力(li)電(dian)(dian)機(ji)部分的加(jia)速(su)(su)(su)(su)(su)或減(jian)(jian)速(su)(su)(su)(su)(su)通常選擇(ze)變速(su)(su)(su)(su)(su)齒(chi)輪箱實現。本齒(chi)輪箱力(li)方(fang)向(xiang)(xiang)變更過(guo)程便(bian)是通過(guo)大(da)(da)齒(chi)咬(yao)合(he)電(dian)(dian)樞(shu)(shu)蝸桿來(lai)實現垂直轉(zhuan)(zhuan)換(huan)成水(shui)平方(fang)向(xiang)(xiang)的過(guo)程。其減(jian)(jian)速(su)(su)(su)(su)(su)的過(guo)程則是通過(guo)大(da)(da)齒(chi)旋轉(zhuan)(zhuan)帶動(dong)小(xiao)齒(chi)配(pei)合(he)天窗機(ji)械結構輸出來(lai)控制整個(ge)產品(pin)前(qian)后、開(kai)閉的移動(dong)的過(guo)程。一般電(dian)(dian)機(ji)在同等功(gong)率(lv)條件下,轉(zhuan)(zhuan)速(su)(su)(su)(su)(su)越(yue)(yue)(yue)快的齒(chi)輪,軸所受的力(li)矩就(jiu)越(yue)(yue)(yue)小(xiao)。因此(ci)(ci)為(wei)(wei)(wei)了減(jian)(jian)少力(li)矩又能快速(su)(su)(su)(su)(su)降低轉(zhuan)(zhuan)速(su)(su)(su)(su)(su),選擇(ze)了大(da)(da)齒(chi)輪與電(dian)(dian)樞(shu)(shu)蝸桿配(pei)合(he)結構。由于大(da)(da)小(xiao)齒(chi)輪的齒(chi)數比就(jiu)是馬達轉(zhuan)(zhuan)速(su)(su)(su)(su)(su)的傳速(su)(su)(su)(su)(su)比,為(wei)(wei)(wei)滿足該電(dian)(dian)機(ji)轉(zhuan)(zhuan)速(su)(su)(su)(su)(su)要求,設(she)計了轉(zhuan)(zhuan)速(su)(su)(su)(su)(su)比2:1的齒(chi)輪咬(yao)合(he)結構。但要特別注意若設(she)J為(wei)(wei)(wei)減(jian)(jian)速(su)(su)(su)(su)(su)機(ji)的效率(lv),設(she)一級(ji)(ji)齒(chi)輪嚙合(he)的效率(lv)中心值為(wei)(wei)(wei)95%,那么2級(ji)(ji)減(jian)(jian)速(su)(su)(su)(su)(su)的J=95%*95% ,3級(ji)(ji)減(jian)(jian)速(su)(su)(su)(su)(su)的J=95%*95%*95% ,以(yi)此(ci)(ci)類推。齒(chi)輪減(jian)(jian)速(su)(su)(su)(su)(su)等級(ji)(ji)越(yue)(yue)(yue)多減(jian)(jian)速(su)(su)(su)(su)(su)效率(lv)越(yue)(yue)(yue)小(xiao)。

篇9

一是強化對法律(lv)援助辦(ban)案質量的監督(du)管(guan)理。并(bing)將回(hui)訪情況與補貼發放相結(jie)合,督(du)促(cu)法律(lv)援助工(gong)作(zuo)人(ren)員不斷提(ti)升服務標準。

二是進(jin)一步降低法(fa)(fa)律(lv)(lv)援(yuan)(yuan)助(zhu)(zhu)(zhu)門檻。將法(fa)(fa)律(lv)(lv)援(yuan)(yuan)助(zhu)(zhu)(zhu)經濟困(kun)難(nan)標準(zhun)調整至市(shi)最低工資標準(zhun)以內,努力實現(xian)“應援(yuan)(yuan)盡援(yuan)(yuan)”,在繼續做(zuo)好“資深律(lv)(lv)師點援(yuan)(yuan)制”、“法(fa)(fa)律(lv)(lv)援(yuan)(yuan)助(zhu)(zhu)(zhu)進(jin)社區‘雙(shuang)百’服(fu)務”等活動的同時,開(kai)展“法(fa)(fa)律(lv)(lv)援(yuan)(yuan)助(zhu)(zhu)(zhu)走基層”主題(ti)實踐活動,擴大法(fa)(fa)律(lv)(lv)援(yuan)(yuan)助(zhu)(zhu)(zhu)受援(yuan)(yuan)覆蓋面,做(zuo)好特殊人群的法(fa)(fa)律(lv)(lv)援(yuan)(yuan)助(zhu)(zhu)(zhu)工作。

三(san)是(shi)創新宣(xuan)傳(chuan)(chuan)形式(shi),拓(tuo)寬(kuan)宣(xuan)傳(chuan)(chuan)渠道。不(bu)斷提升(sheng)區(qu)法律援(yuan)(yuan)(yuan)(yuan)助工作(zuo)的知名度和(he)影響力。首(shou)先,創建(jian)區(qu)法律援(yuan)(yuan)(yuan)(yuan)助微(wei)博平臺(tai),利用微(wei)博開展(zhan)“微(wei)服(fu)(fu)務(wu)”,定(ding)期更新法律知識,隨時解答群(qun)眾(zhong)咨詢。其次(ci),設立(li)便民服(fu)(fu)務(wu)自助終端,方便群(qun)眾(zhong)查詢法律援(yuan)(yuan)(yuan)(yuan)助相關(guan)(guan)信(xin)息。另外,拓(tuo)展(zhan)電視、廣(guang)播宣(xuan)傳(chuan)(chuan)專欄(lan),策(ce)劃(hua)法律援(yuan)(yuan)(yuan)(yuan)助專版專題報道;制作(zuo)法律援(yuan)(yuan)(yuan)(yuan)助申請指南(nan)和(he)相關(guan)(guan)法律知識的宣(xuan)傳(chuan)(chuan)材料,開展(zhan)持續、多(duo)樣的宣(xuan)傳(chuan)(chuan)活(huo)動。

篇10

【關(guan)鍵字】電(dian)動機;絕緣電(dian)阻;絕緣材(cai)料(liao);環境因素;測(ce)量

引言

測(ce)量(liang)電機(ji)的(de)(de)絕(jue)緣電阻是檢測(ce)電機(ji)絕(jue)緣性能(neng)(neng)最常用(yong)、最簡(jian)便且比(bi)較(jiao)有效的(de)(de)方法(fa)。如果(guo)測(ce)量(liang)中(zhong)所使(shi)用(yong)的(de)(de)方法(fa)不當,測(ce)得(de)結果(guo)將無法(fa)成為評估電機(ji)絕(jue)緣性能(neng)(neng)并確定其能(neng)(neng)否安全運行的(de)(de)判斷(duan)依據。下面針對電機(ji)絕(jue)緣測(ce)量(liang)中(zhong)的(de)(de)五(wu)種誤區,進行分(fen)析討論(lun)。

誤區一:萬用表(biao)測量低(di)壓(ya)電機絕(jue)緣電阻。

從表(biao)1可(ke)知,萬(wan)(wan)用(yong)(yong)(yong)(yong)表(biao)歐姆檔(dang)雖然是測(ce)量電(dian)(dian)(dian)阻(zu),但其表(biao)內的(de)(de)工作(zuo)電(dian)(dian)(dian)壓(ya)(ya)(ya)相當低(di)(di)(di),如FM500型萬(wan)(wan)用(yong)(yong)(yong)(yong)表(biao)的(de)(de)低(di)(di)(di)電(dian)(dian)(dian)阻(zu)檔(dang)1.5V,高阻(zu)擋為(wei)9V;MASTECH MY68數字萬(wan)(wan)用(yong)(yong)(yong)(yong)表(biao)工作(zuo)電(dian)(dian)(dian)壓(ya)(ya)(ya)為(wei)9V。顯然,如此(ci)低(di)(di)(di)的(de)(de)電(dian)(dian)(dian)壓(ya)(ya)(ya)(萬(wan)(wan)用(yong)(yong)(yong)(yong)表(biao)表(biao)筆上的(de)(de)測(ce)試電(dian)(dian)(dian)壓(ya)(ya)(ya)比(bi)工作(zuo)電(dian)(dian)(dian)壓(ya)(ya)(ya)更低(di)(di)(di))用(yong)(yong)(yong)(yong)于低(di)(di)(di)壓(ya)(ya)(ya)電(dian)(dian)(dian)機(ji)(ji)絕(jue)緣(yuan)電(dian)(dian)(dian)阻(zu)的(de)(de)測(ce)量,根本無法(fa)正(zheng)確反映其在額(e)定工作(zuo)電(dian)(dian)(dian)壓(ya)(ya)(ya)或(huo)更高電(dian)(dian)(dian)壓(ya)(ya)(ya)條件下(xia)的(de)(de)絕(jue)緣(yuan)電(dian)(dian)(dian)阻(zu),所以用(yong)(yong)(yong)(yong)萬(wan)(wan)用(yong)(yong)(yong)(yong)表(biao)或(huo)直流低(di)(di)(di)壓(ya)(ya)(ya)電(dian)(dian)(dian)橋所測(ce)的(de)(de)值(zhi)根本不是低(di)(di)(di)壓(ya)(ya)(ya)電(dian)(dian)(dian)機(ji)(ji)的(de)(de)絕(jue)緣(yuan)阻(zu)值(zhi)。因此(ci),測(ce)量低(di)(di)(di)壓(ya)(ya)(ya)電(dian)(dian)(dian)機(ji)(ji)絕(jue)緣(yuan)阻(zu)值(zhi)只能用(yong)(yong)(yong)(yong)絕(jue)緣(yuan)電(dian)(dian)(dian)阻(zu)表(biao)。

誤區二:絕緣測試儀檢查低壓電機(ji)短路情況。

絕(jue)緣(yuan)(yuan)(yuan)(yuan)的(de)(de)(de)好壞與是否短路(lu)(lu)(lu)是兩個(ge)不(bu)同的(de)(de)(de)概念,電(dian)(dian)(dian)機(ji)的(de)(de)(de)絕(jue)緣(yuan)(yuan)(yuan)(yuan)水平差并不(bu)代表電(dian)(dian)(dian)機(ji)內(nei)部繞(rao)組(zu)(zu)發生了短路(lu)(lu)(lu)情況,而短路(lu)(lu)(lu)則表示絕(jue)緣(yuan)(yuan)(yuan)(yuan)損壞或(huo)電(dian)(dian)(dian)機(ji)繞(rao)組(zu)(zu)或(huo)其他部件對電(dian)(dian)(dian)路(lu)(lu)(lu)短接(jie)的(de)(de)(de)故(gu)障。當使(shi)用(yong)手搖式(shi)兆歐(ou)表測(ce)(ce)量繞(rao)組(zu)(zu)的(de)(de)(de)絕(jue)緣(yuan)(yuan)(yuan)(yuan)電(dian)(dian)(dian)阻時,若出現了“0MΩ”時,并不(bu)意味(wei)這電(dian)(dian)(dian)機(ji)繞(rao)組(zu)(zu)或(huo)其內(nei)部已發生接(jie)地(di)或(huo)短路(lu)(lu)(lu),因為從0MΩ起始刻度的(de)(de)(de)絕(jue)緣(yuan)(yuan)(yuan)(yuan)表就很難(nan)辨(bian)認(ren)100kΩ以下的(de)(de)(de)數值。即便使(shi)用(yong)FLUKE 1508絕(jue)緣(yuan)(yuan)(yuan)(yuan)測(ce)(ce)試(shi)功能,在其測(ce)(ce)量范圍(0.01MΩ~10GΩ)內(nei),也(ye)無法辨(bian)認(ren)10kΩ以下的(de)(de)(de)數值。判斷(duan)電(dian)(dian)(dian)機(ji)絕(jue)緣(yuan)(yuan)(yuan)(yuan)的(de)(de)(de)優劣應當用(yong)絕(jue)緣(yuan)(yuan)(yuan)(yuan)測(ce)(ce)試(shi)儀測(ce)(ce)量,判斷(duan)電(dian)(dian)(dian)機(ji)繞(rao)組(zu)(zu)是否短路(lu)(lu)(lu)應用(yong)帶有歐(ou)姆檔的(de)(de)(de)絕(jue)緣(yuan)(yuan)(yuan)(yuan)電(dian)(dian)(dian)阻測(ce)(ce)試(shi)儀或(huo)萬(wan)用(yong)表歐(ou)姆檔測(ce)(ce)量。

誤區三:忽略影(ying)響絕緣電(dian)阻(zu)的因素。

在進行絕緣(yuan)電阻測試(shi)時,絕緣(yuan)材料的狀況、環境相對濕度、溫(wen)度等會對測量結果產生重大影響(xiang)。

1)絕(jue)(jue)緣(yuan)(yuan)材(cai)(cai)料(liao)的(de)(de)老化與擊(ji)穿(chuan)(chuan)。我廠絕(jue)(jue)大(da)多數低壓(ya)電(dian)機的(de)(de)絕(jue)(jue)緣(yuan)(yuan)等(deng)(deng)級為(wei)F,該絕(jue)(jue)緣(yuan)(yuan)材(cai)(cai)料(liao)系統采用熱(re)固性(xing)環氧(yang)或聚酯粘合形(xing)成(cheng),在長期的(de)(de)氧(yang)化、聚合、分解、揮(hui)發等(deng)(deng)化學過程(cheng)作用下(xia),造(zao)(zao)成(cheng)絕(jue)(jue)緣(yuan)(yuan)彈性(xing)喪失(shi)、變脆、吸潮(chao)性(xing)能(neng)增加(jia)、電(dian)導增大(da)等(deng)(deng),導致(zhi)絕(jue)(jue)緣(yuan)(yuan)性(xing)能(neng)下(xia)降。絕(jue)(jue)緣(yuan)(yuan)材(cai)(cai)料(liao)的(de)(de)擊(ji)穿(chuan)(chuan)可(ke)分為(wei)熱(re)擊(ji)穿(chuan)(chuan)和純電(dian)擊(ji)穿(chuan)(chuan)兩(liang)種(zhong)情況,熱(re)擊(ji)穿(chuan)(chuan)是絕(jue)(jue)緣(yuan)(yuan)材(cai)(cai)料(liao)所加(jia)的(de)(de)電(dian)壓(ya)與材(cai)(cai)料(liao)發熱(re)使絕(jue)(jue)緣(yuan)(yuan)性(xing)能(neng)變劣(lie)所引(yin)起的(de)(de)。純電(dian)擊(ji)穿(chuan)(chuan)是在電(dian)場力作用下(xia),造(zao)(zao)成(cheng)絕(jue)(jue)緣(yuan)(yuan)材(cai)(cai)料(liao)結構直接破壞引(yin)起的(de)(de)。

2)潮濕的(de)(de)影響。不考慮繞組表(biao)面(mian)是否污穢的(de)(de)情況下,繞組絕(jue)(jue)(jue)(jue)緣(yuan)對(dui)環境的(de)(de)相(xiang)對(dui)濕度(du)是很敏感的(de)(de),只(zhi)要相(xiang)對(dui)濕度(du)足夠大,如多雨(yu)天(tian)或長時間的(de)(de)雨(yu)雪天(tian)氣,絕(jue)(jue)(jue)(jue)緣(yuan)表(biao)面(mian)就(jiu)會形(xing)成潮氣膜,使表(biao)面(mian)絕(jue)(jue)(jue)(jue)緣(yuan)電(dian)(dian)阻變小(xiao),由公式(3)可知(zhi),絕(jue)(jue)(jue)(jue)緣(yuan)電(dian)(dian)阻將降低(di)。若繞組表(biao)面(mian)被污染或有絕(jue)(jue)(jue)(jue)緣(yuan)裂縫存在,當相(xiang)對(dui)濕度(du)足夠大,污染物中(zhong)的(de)(de)電(dian)(dian)導(dao)性物質和吸水性物質會使繞組絕(jue)(jue)(jue)(jue)緣(yuan)的(de)(de)電(dian)(dian)導(dao)性和吸潮性能大大增加,導(dao)致絕(jue)(jue)(jue)(jue)緣(yuan)電(dian)(dian)阻大幅(fu)降低(di)。

3)溫(wen)(wen)度(du)的(de)(de)影響。一般情況下,對于(yu)給定系統在(zai)任意時(shi)間點(dian)的(de)(de)絕(jue)緣(yuan)(yuan)電阻(zu)(zu),隨繞組溫(wen)(wen)度(du)呈指數規(gui)律相反(fan)變(bian)化,由(you)于(yu)溫(wen)(wen)度(du)提高提供了熱能(neng)(neng),使額外(wai)的(de)(de)離子獲得釋放,在(zai)電場(chang)作用下,做(zuo)定向(xiang)移(yi)動(dong)的(de)(de)離子數量(liang)及(ji)其移(yi)動(dong)的(de)(de)速度(du)都將增加,從而(er)降(jiang)低絕(jue)緣(yuan)(yuan)阻(zu)(zu)值(zhi)(zhi)。對于(yu)露點(dian)以(yi)下的(de)(de)電機(ji),在(zai)檢測(ce)其絕(jue)緣(yuan)(yuan)時(shi),絕(jue)緣(yuan)(yuan)阻(zu)(zu)值(zhi)(zhi)可能(neng)(neng)不隨繞組溫(wen)(wen)度(du)相反(fan)變(bian)化,在(zai)低溫(wen)(wen)下,絕(jue)緣(yuan)(yuan)阻(zu)(zu)值(zhi)(zhi)反(fan)而(er)降(jiang)低。這是由(you)于(yu)電機(ji)繞組表(biao)面(mian)受潮(chao)使其表(biao)面(mian)絕(jue)緣(yuan)(yuan)電阻(zu)(zu)下降(jiang)速度(du)遠大于(yu)體積絕(jue)緣(yuan)(yuan)電阻(zu)(zu)上升速度(du)所致。

誤區四:忽略絕(jue)緣電阻的測量時間。

絕(jue)緣(yuan)電(dian)(dian)(dian)阻(zu)反映絕(jue)緣(yuan)材(cai)料在(zai)(zai)一定的(de)直流(liu)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)作用下(xia)通過的(de)泄(xie)漏電(dian)(dian)(dian)流(liu)大小。特別(bie)是(shi)測(ce)量(liang)具有(you)(you)等效電(dian)(dian)(dian)容(rong)性較大的(de)高壓(ya)(ya)(ya)(ya)電(dian)(dian)(dian)機(ji)時(shi)(shi)(shi),還可(ke)明顯的(de)看(kan)到絕(jue)緣(yuan)電(dian)(dian)(dian)阻(zu)值(zhi)與(yu)加(jia)(jia)壓(ya)(ya)(ya)(ya)時(shi)(shi)(shi)間(jian)(jian)有(you)(you)關。加(jia)(jia)壓(ya)(ya)(ya)(ya)時(shi)(shi)(shi)間(jian)(jian)越長(chang),絕(jue)緣(yuan)電(dian)(dian)(dian)阻(zu)值(zhi)就越高。這是(shi)由(you)于絕(jue)緣(yuan)材(cai)料的(de)吸收現象所引起(qi)的(de)。絕(jue)緣(yuan)材(cai)料(電(dian)(dian)(dian)介(jie)(jie)(jie)質(zhi)(zhi))在(zai)(zai)直流(liu)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)的(de)作用下(xia)發生(sheng)極(ji)化過程(cheng)與(yu)電(dian)(dian)(dian)導過程(cheng),電(dian)(dian)(dian)介(jie)(jie)(jie)質(zhi)(zhi)所在(zai)(zai)的(de)回路中將(jiang)產(chan)生(sheng)從(cong)大到小隨(sui)時(shi)(shi)(shi)間(jian)(jian)而衰(shuai)(shuai)(shuai)(shuai)減(jian)并最終穩定在(zai)(zai)一定數值(zhi)的(de)電(dian)(dian)(dian)流(liu)。該電(dian)(dian)(dian)流(liu)有(you)(you)三個分(fen)量(liang)組成:①快(kuai)速(su)極(ji)化過程(cheng)中產(chan)生(sheng)的(de)極(ji)化電(dian)(dian)(dian)流(liu)(幾何電(dian)(dian)(dian)容(rong)電(dian)(dian)(dian)流(liu)),它(ta)在(zai)(zai)電(dian)(dian)(dian)介(jie)(jie)(jie)質(zhi)(zhi)加(jia)(jia)壓(ya)(ya)(ya)(ya)后存在(zai)(zai)的(de)時(shi)(shi)(shi)間(jian)(jian)極(ji)短,很快(kuai)就衰(shuai)(shuai)(shuai)(shuai)減(jian)為(wei)(wei)零(ling)。②有(you)(you)損極(ji)化時(shi)(shi)(shi)產(chan)生(sheng)的(de)夾層(ceng)式(shi)(shi)極(ji)化和偶極(ji)子式(shi)(shi)極(ji)化的(de)電(dian)(dian)(dian)流(liu),即吸收電(dian)(dian)(dian)流(liu)。它(ta)隨(sui)時(shi)(shi)(shi)間(jian)(jian)衰(shuai)(shuai)(shuai)(shuai)減(jian),衰(shuai)(shuai)(shuai)(shuai)減(jian)速(su)度取(qu)決于電(dian)(dian)(dian)介(jie)(jie)(jie)質(zhi)(zhi)的(de)材(cai)料和結構等因素。對(dui)于等效電(dian)(dian)(dian)容(rong)性較小的(de)低壓(ya)(ya)(ya)(ya)電(dian)(dian)(dian)機(ji)而言,通常在(zai)(zai)一分(fen)鐘左右的(de)時(shi)(shi)(shi)間(jian)(jian)便衰(shuai)(shuai)(shuai)(shuai)減(jian)至零(ling)。③泄(xie)漏電(dian)(dian)(dian)流(liu),由(you)公(gong)式(shi)(shi)(2)可(ke)知,它(ta)不隨(sui)加(jia)(jia)壓(ya)(ya)(ya)(ya)時(shi)(shi)(shi)間(jian)(jian)而變化。上(shang)述三種(zhong)電(dian)(dian)(dian)流(liu)分(fen)量(liang)在(zai)(zai)每個時(shi)(shi)(shi)刻(ke)疊(die)加(jia)(jia)起(qi)來(lai),即為(wei)(wei)流(liu)過電(dian)(dian)(dian)介(jie)(jie)(jie)質(zhi)(zhi)的(de)總電(dian)(dian)(dian)流(liu)。

誤區(qu)五:忽(hu)略(lve)吸收比K的測量。

在(zai)(zai)低壓電(dian)(dian)(dian)機絕(jue)緣測(ce)量(liang)的過程(cheng)中,某一時刻(ke)的絕(jue)緣電(dian)(dian)(dian)阻(zu)值(zhi)有(you)時難以全面反映電(dian)(dian)(dian)機絕(jue)緣性能的優劣,尤其是在(zai)(zai)油膩環(huan)(huan)境和(he)潮(chao)濕環(huan)(huan)境特別明顯(xian)。其原因有(you)兩點:①絕(jue)緣電(dian)(dian)(dian)阻(zu)的大小(xiao)與(yu)泄漏(lou)電(dian)(dian)(dian)流流經(jing)路(lu)徑的面積成反比,與(yu)泄漏(lou)電(dian)(dian)(dian)流流經(jing)路(lu)徑的長(chang)度成正比。因此絕(jue)緣電(dian)(dian)(dian)阻(zu)不僅與(yu)絕(jue)緣材(cai)料材(cai)質(zhi)有(you)關,而且與(yu)其形狀、尺寸(cun)等諸多因素(su)有(you)關,往往難以給出一定的絕(jue)緣電(dian)(dian)(dian)阻(zu)判斷標準,而只能與(yu)該(gai)絕(jue)緣的過去(qu)測(ce)量(liang)值(zhi)進行比較。②絕(jue)緣材(cai)料加上測(ce)試(shi)電(dian)(dian)(dian)壓后(hou)均存在(zai)(zai)對電(dian)(dian)(dian)荷的極化(hua)過程(cheng)。

基(ji)于以上分析可(ke)知(zhi),在油(you)膩環境和潮濕環境的(de)里,對于等效電(dian)容性較小(xiao)的(de)低壓(ya)電(dian)機,利(li)用絕(jue)緣電(dian)阻(zu)的(de)吸收比K(極化指數(shu)P.I.的(de)派生)更有(you)利(li)于判斷絕(jue)緣狀(zhuang)況的(de)優劣。即絕(jue)緣介(jie)質加壓(ya)60s與加壓(ya)15s時的(de)直(zhi)流電(dian)阻(zu)的(de)比值:

(4)

由(you)絕緣電(dian)介質(zhi)的(de)吸收(shou)現象、公式(4)以及表2可知,K值(zhi)低于1.3表明絕緣存在(zai)問(wen)題(ti)。在(zai)實(shi)際工作中,使用FLUKE 1508測(ce)試(shi)吸收(shou)比K,只需選擇吸收(shou)比檔和(he)適合(he)的(de)測(ce)試(shi)電(dian)壓即可。

結 論

絕(jue)緣材料電(dian)氣性能的(de)(de)好(hao)壞,直接影響到低壓電(dian)機設備運(yun)行的(de)(de)可靠性和安全性。因此,電(dian)氣絕(jue)緣測(ce)量是電(dian)氣技術工(gong)(gong)(gong)作的(de)(de)重要(yao)內容,也是安全生產和經濟效益的(de)(de)重要(yao)保證,這對(dui)于(yu)電(dian)氣工(gong)(gong)(gong)作者在工(gong)(gong)(gong)作責(ze)任心和專(zhuan)業素質等方面的(de)(de)要(yao)求很高。以上對(dui)于(yu)低壓電(dian)機設備絕(jue)緣測(ce)量方面的(de)(de)五種(zhong)誤(wu)區的(de)(de)分(fen)析討(tao)論(lun),是從(cong)事電(dian)氣技術工(gong)(gong)(gong)作的(de)(de)一(yi)些認識和探索。在實際工(gong)(gong)(gong)作中,還(huan)有(you)一(yi)些值得重視的(de)(de)知識要(yao)點需要(yao)討(tao)論(lun),如對(dui)被測(ce)對(dui)象在測(ce)量前的(de)(de)適當處理和測(ce)量操(cao)作的(de)(de)規范要(yao)求等。

參考文獻

[1]GB/T 20160-2006 旋轉電機絕(jue)緣電阻測試[S].

[2]屠志(zhi)健(jian)、張(zhang)一塵. 電(dian)氣絕緣與過電(dian)壓[M]. 北京:中(zhong)國電(dian)力(li)出(chu)版社,2005.