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)電轉化為交(jiao)(jiao)流(liu)電的(de)裝(zhuang)置,若直(zhi)(zhi)流(liu)電壓(ya)較低,則通(tong)過交(jiao)(jiao)流(liu)變(bian)(bian)壓(ya)器升(sheng)壓(ya),即得到(dao)標準交(jiao)(jiao)流(liu)電壓(ya)和頻率。大容(rong)量逆變(bian)(bian)器的(de)直(zhi)(zhi)流(liu)母(mu)線電壓(ya)較高,交(jiao)(jiao)流(liu)輸(shu)出一般不需要(yao)變(bian)(bian)壓(ya)器升(sheng)壓(ya)即能達到(dao)220V,在中、小容(rong)量的(de)逆變(bian)(bian)器中,由于直(zhi)(zhi)流(liu)電壓(ya)較低,就必須設計升(sheng)壓(ya)電路。
光伏逆變器的工作原理
大容量光伏逆變(bian)(bian)器是(shi)由升壓(ya)回路(lu)和逆變(bian)(bian)橋(qiao)式回路(lu)構成的(de)(de)(de)(de),其工(gong)作原理很簡單。升壓(ya)回路(lu)把太陽電(dian)池的(de)(de)(de)(de)直(zhi)流(liu)(liu)電(dian)壓(ya)升壓(ya)到逆變(bian)(bian)器輸出(chu)控制(zhi)所(suo)需(xu)的(de)(de)(de)(de)直(zhi)流(liu)(liu)電(dian)壓(ya),逆變(bian)(bian)橋(qiao)式回路(lu)則把升壓(ya)后的(de)(de)(de)(de)直(zhi)流(liu)(liu)電(dian)壓(ya)等價地轉換(huan)成常用頻率的(de)(de)(de)(de)交流(liu)(liu)電(dian)壓(ya),這就是(shi)它的(de)(de)(de)(de)原理。
中、小容量逆變(bian)器(qi)一(yi)般有推(tui)挽逆變(bian)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)、全橋(qiao)逆變(bian)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)這兩(liang)種逆變(bian)橋(qiao)式回路(lu)(lu)。推(tui)挽電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)能將升壓變(bian)壓器(qi)的(de)中性(xing)(xing)插頭接于(yu)正(zheng)電(dian)(dian)(dian)(dian)(dian)源(yuan),兩(liang)只功率管(guan)(guan)交(jiao)替工作(zuo),輸出得到(dao)交(jiao)流電(dian)(dian)(dian)(dian)(dian)力,由于(yu)功率晶體管(guan)(guan)共(gong)(gong)地邊(bian)接,驅動及控制(zhi)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)簡單,且變(bian)壓器(qi)具有一(yi)定的(de)漏感,因此(ci)它可(ke)以限(xian)制(zhi)短路(lu)(lu)電(dian)(dian)(dian)(dian)(dian)流,因而提高(gao)了電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)的(de)可(ke)靠(kao)性(xing)(xing)。全橋(qiao)逆變(bian)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)具有續流回路(lu)(lu),即使有感性(xing)(xing)負載(zai),輸出電(dian)(dian)(dian)(dian)(dian)壓波形也(ye)不會(hui)畸變(bian),但它必(bi)須(xu)采用(yong)專門驅動電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)才(cai)能正(zheng)常使用(yong)。為防止上、下橋(qiao)臂發生共(gong)(gong)同導通,全橋(qiao)逆變(bian)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)必(bi)須(xu)設置死區時間,才(cai)不會(hui)出錯,因此(ci)它的(de)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)結構較復雜。
光伏逆變器怎么選
1、光(guang)伏逆(ni)變器的大小應根據土(tu)地或者屋頂使(shi)用面積(ji)來計算(suan),計算(suan)時要考慮到傾斜角度、支(zhi)架安裝方式等,以盡量不出現陰影遮(zhe)擋為原則。
2、光(guang)伏逆(ni)變(bian)器(qi)MPPT的路(lu)數(shu)在很大程度上(shang)決定著一個(ge)光(guang)伏電(dian)站的發電(dian)量,而逆(ni)變(bian)器(qi)輸(shu)入路(lu)數(shu)往往決定了一個(ge)光(guang)伏電(dian)站是否(fou)更加容(rong)易進行配板(ban)設計,因此購(gou)買前,一定要想(xiang)好MPPT的路(lu)數(shu)要多少。
3、光伏逆(ni)變器(qi)的散熱方式有強(qiang)制風冷、自然冷卻、水冷三種(zhong),其中(zhong)水冷方式主要應用于大型集中(zhong)式逆(ni)變器(qi)且應用較(jiao)(jiao)少。從逆(ni)變器(qi)角度來看,家庭(ting)用單相逆(ni)變器(qi)功率等級較(jiao)(jiao)低,散熱較(jiao)(jiao)少,選(xuan)擇強(qiang)制風冷即可。