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(jiang)直(zhi)(zhi)流(liu)電(dian)(dian)(dian)(dian)(dian)轉化為交流(liu)電(dian)(dian)(dian)(dian)(dian)的(de)裝置,若直(zhi)(zhi)流(liu)電(dian)(dian)(dian)(dian)(dian)壓較低,則通過交流(liu)變(bian)壓器升壓,即(ji)得到(dao)標準交流(liu)電(dian)(dian)(dian)(dian)(dian)壓和頻(pin)率。大容量逆變(bian)器的(de)直(zhi)(zhi)流(liu)母線電(dian)(dian)(dian)(dian)(dian)壓較高,交流(liu)輸出一般不需要變(bian)壓器升壓即(ji)能達到(dao)220V,在中、小容量的(de)逆變(bian)器中,由于直(zhi)(zhi)流(liu)電(dian)(dian)(dian)(dian)(dian)壓較低,就必須(xu)設計(ji)升壓電(dian)(dian)(dian)(dian)(dian)路。
光伏逆變器的工作原理
大容量光伏逆(ni)變器是(shi)由升壓回路(lu)和逆(ni)變橋式(shi)回路(lu)構(gou)成的(de)(de)(de),其工作原(yuan)理(li)(li)很(hen)簡單(dan)。升壓回路(lu)把(ba)太(tai)陽(yang)電(dian)池的(de)(de)(de)直(zhi)流(liu)電(dian)壓升壓到逆(ni)變器輸出控制(zhi)所需(xu)的(de)(de)(de)直(zhi)流(liu)電(dian)壓,逆(ni)變橋式(shi)回路(lu)則把(ba)升壓后的(de)(de)(de)直(zhi)流(liu)電(dian)壓等價(jia)地轉換(huan)成常(chang)用頻(pin)率的(de)(de)(de)交流(liu)電(dian)壓,這就是(shi)它(ta)的(de)(de)(de)原(yuan)理(li)(li)。
中、小(xiao)容(rong)量(liang)逆變器一(yi)般(ban)有(you)推(tui)(tui)挽逆變電(dian)(dian)(dian)路(lu)、全(quan)橋逆變電(dian)(dian)(dian)路(lu)這兩種逆變橋式回路(lu)。推(tui)(tui)挽電(dian)(dian)(dian)路(lu)能將(jiang)升(sheng)壓變壓器的(de)(de)中性插頭接于正電(dian)(dian)(dian)源,兩只功(gong)率(lv)管交替工(gong)作,輸(shu)出(chu)得到交流(liu)電(dian)(dian)(dian)力(li),由于功(gong)率(lv)晶體管共地邊接,驅(qu)動(dong)及控(kong)制(zhi)(zhi)電(dian)(dian)(dian)路(lu)簡單,且變壓器具有(you)一(yi)定的(de)(de)漏感,因(yin)此(ci)它(ta)可(ke)以限制(zhi)(zhi)短路(lu)電(dian)(dian)(dian)流(liu),因(yin)而(er)提高(gao)了電(dian)(dian)(dian)路(lu)的(de)(de)可(ke)靠(kao)性。全(quan)橋逆變電(dian)(dian)(dian)路(lu)具有(you)續流(liu)回路(lu),即(ji)使有(you)感性負載(zai),輸(shu)出(chu)電(dian)(dian)(dian)壓波形也不會(hui)畸變,但它(ta)必須采用(yong)(yong)專門驅(qu)動(dong)電(dian)(dian)(dian)路(lu)才能正常使用(yong)(yong)。為防(fang)止上、下(xia)橋臂發生共同(tong)導通,全(quan)橋逆變電(dian)(dian)(dian)路(lu)必須設置死區時間,才不會(hui)出(chu)錯,因(yin)此(ci)它(ta)的(de)(de)電(dian)(dian)(dian)路(lu)結(jie)構(gou)較復雜。
光伏逆變器怎么選
1、光伏逆變(bian)器的大小應根據(ju)土地或者(zhe)屋頂使用(yong)面積來計算,計算時要考慮到傾斜角(jiao)度(du)、支架安(an)裝方式等,以盡量(liang)不出現陰影遮(zhe)擋為原則。
2、光(guang)伏逆(ni)變器MPPT的(de)路數在很大程度(du)上決定(ding)著一(yi)(yi)(yi)個(ge)光(guang)伏電(dian)站的(de)發(fa)電(dian)量,而逆(ni)變器輸入路數往往決定(ding)了一(yi)(yi)(yi)個(ge)光(guang)伏電(dian)站是否更加容易進行配板(ban)設(she)計,因此(ci)購買前,一(yi)(yi)(yi)定(ding)要(yao)想好MPPT的(de)路數要(yao)多少(shao)。
3、光(guang)伏逆(ni)變器(qi)的散熱(re)(re)方式(shi)有強(qiang)制風冷(leng)、自然冷(leng)卻、水冷(leng)三種,其中(zhong)水冷(leng)方式(shi)主要應用(yong)(yong)于(yu)大型(xing)集中(zhong)式(shi)逆(ni)變器(qi)且應用(yong)(yong)較少。從逆(ni)變器(qi)角度來看,家庭用(yong)(yong)單相(xiang)逆(ni)變器(qi)功率等級較低,散熱(re)(re)較少,選(xuan)擇(ze)強(qiang)制風冷(leng)即(ji)可。