光伏逆變器的功能
光伏逆變器是一種電源調整器,可分為獨立型電源用和并網用兩種類型。光伏逆變器品牌產品能將直(zhi)(zhi)流(liu)電(dian)(dian)轉化為交(jiao)(jiao)流(liu)電(dian)(dian)的(de)裝置,若直(zhi)(zhi)流(liu)電(dian)(dian)壓(ya)較低,則通過(guo)交(jiao)(jiao)流(liu)變(bian)壓(ya)器(qi)升(sheng)壓(ya),即得到(dao)(dao)標準(zhun)交(jiao)(jiao)流(liu)電(dian)(dian)壓(ya)和頻率。大(da)容(rong)量(liang)逆變(bian)器(qi)的(de)直(zhi)(zhi)流(liu)母(mu)線電(dian)(dian)壓(ya)較高(gao),交(jiao)(jiao)流(liu)輸出(chu)一(yi)般不需要變(bian)壓(ya)器(qi)升(sheng)壓(ya)即能達到(dao)(dao)220V,在中、小容(rong)量(liang)的(de)逆變(bian)器(qi)中,由(you)于直(zhi)(zhi)流(liu)電(dian)(dian)壓(ya)較低,就必須設計(ji)升(sheng)壓(ya)電(dian)(dian)路。
光伏逆變器的工作原理
大容量(liang)光(guang)伏逆變(bian)器(qi)是(shi)(shi)由升(sheng)(sheng)壓(ya)(ya)回(hui)路和逆變(bian)橋式(shi)回(hui)路構(gou)成的,其工作原理(li)(li)很簡單。升(sheng)(sheng)壓(ya)(ya)回(hui)路把(ba)太陽電(dian)池(chi)的直(zhi)(zhi)流電(dian)壓(ya)(ya)升(sheng)(sheng)壓(ya)(ya)到逆變(bian)器(qi)輸出控(kong)制所需的直(zhi)(zhi)流電(dian)壓(ya)(ya),逆變(bian)橋式(shi)回(hui)路則把(ba)升(sheng)(sheng)壓(ya)(ya)后的直(zhi)(zhi)流電(dian)壓(ya)(ya)等價(jia)地轉換成常用頻率的交流電(dian)壓(ya)(ya),這(zhe)就是(shi)(shi)它的原理(li)(li)。
中、小容量(liang)逆(ni)變(bian)(bian)(bian)器一般有推挽逆(ni)變(bian)(bian)(bian)電(dian)(dian)(dian)路(lu)(lu)(lu)、全(quan)(quan)橋逆(ni)變(bian)(bian)(bian)電(dian)(dian)(dian)路(lu)(lu)(lu)這兩種逆(ni)變(bian)(bian)(bian)橋式回路(lu)(lu)(lu)。推挽電(dian)(dian)(dian)路(lu)(lu)(lu)能(neng)將升壓(ya)(ya)變(bian)(bian)(bian)壓(ya)(ya)器的(de)中性(xing)(xing)插(cha)頭接于(yu)正電(dian)(dian)(dian)源,兩只功(gong)率管交替工作,輸出(chu)得到交流電(dian)(dian)(dian)力,由(you)于(yu)功(gong)率晶體管共地邊接,驅動及控(kong)制電(dian)(dian)(dian)路(lu)(lu)(lu)簡單,且變(bian)(bian)(bian)壓(ya)(ya)器具(ju)有一定(ding)的(de)漏感(gan),因(yin)此它(ta)可(ke)以限制短路(lu)(lu)(lu)電(dian)(dian)(dian)流,因(yin)而提高了電(dian)(dian)(dian)路(lu)(lu)(lu)的(de)可(ke)靠性(xing)(xing)。全(quan)(quan)橋逆(ni)變(bian)(bian)(bian)電(dian)(dian)(dian)路(lu)(lu)(lu)具(ju)有續(xu)流回路(lu)(lu)(lu),即使有感(gan)性(xing)(xing)負載,輸出(chu)電(dian)(dian)(dian)壓(ya)(ya)波(bo)形也不會畸變(bian)(bian)(bian),但它(ta)必須(xu)采用專門驅動電(dian)(dian)(dian)路(lu)(lu)(lu)才能(neng)正常使用。為防止上、下橋臂(bei)發(fa)生共同導通,全(quan)(quan)橋逆(ni)變(bian)(bian)(bian)電(dian)(dian)(dian)路(lu)(lu)(lu)必須(xu)設置死(si)區時間,才不會出(chu)錯(cuo),因(yin)此它(ta)的(de)電(dian)(dian)(dian)路(lu)(lu)(lu)結構較(jiao)復雜(za)。
光伏逆變器怎么選
1、光伏逆變器的(de)大小應根據土地(di)或者屋頂(ding)使用(yong)面積來(lai)計算(suan),計算(suan)時要考慮到傾斜角度(du)、支架(jia)安裝(zhuang)方式等,以盡(jin)量不出現陰影遮擋為(wei)原(yuan)則。
2、光伏(fu)逆變(bian)器MPPT的(de)(de)路數在很大(da)程度上決定(ding)(ding)著一個光伏(fu)電站(zhan)的(de)(de)發電量,而逆變(bian)器輸入路數往往決定(ding)(ding)了一個光伏(fu)電站(zhan)是否更(geng)加容易(yi)進行(xing)配板設(she)計,因此購買(mai)前,一定(ding)(ding)要想好(hao)MPPT的(de)(de)路數要多少。
3、光伏逆變(bian)器的散熱(re)方(fang)(fang)式有強(qiang)制風(feng)冷、自然冷卻(que)、水冷三種,其中水冷方(fang)(fang)式主要應(ying)用(yong)(yong)于大型(xing)集中式逆變(bian)器且應(ying)用(yong)(yong)較少。從逆變(bian)器角度來看,家庭用(yong)(yong)單相逆變(bian)器功率(lv)等(deng)級較低,散熱(re)較少,選擇(ze)強(qiang)制風(feng)冷即可。