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)流電(dian)(dian)轉化為交流電(dian)(dian)的(de)裝置,若直(zhi)(zhi)流電(dian)(dian)壓(ya)較低,則通過(guo)交流變(bian)(bian)壓(ya)器升(sheng)壓(ya),即得(de)到標(biao)準交流電(dian)(dian)壓(ya)和頻率。大容量逆變(bian)(bian)器的(de)直(zhi)(zhi)流母線電(dian)(dian)壓(ya)較高(gao),交流輸出一(yi)般不需要變(bian)(bian)壓(ya)器升(sheng)壓(ya)即能達到220V,在中、小容量的(de)逆變(bian)(bian)器中,由(you)于直(zhi)(zhi)流電(dian)(dian)壓(ya)較低,就必須設計升(sheng)壓(ya)電(dian)(dian)路。
光伏逆變器的工作原理
大容量光(guang)伏逆(ni)變(bian)器是由升壓(ya)(ya)回(hui)路(lu)和逆(ni)變(bian)橋(qiao)式回(hui)路(lu)構成的(de)(de),其工作原理(li)很簡單。升壓(ya)(ya)回(hui)路(lu)把太陽電池的(de)(de)直流電壓(ya)(ya)升壓(ya)(ya)到逆(ni)變(bian)器輸出控制(zhi)所需的(de)(de)直流電壓(ya)(ya),逆(ni)變(bian)橋(qiao)式回(hui)路(lu)則(ze)把升壓(ya)(ya)后(hou)的(de)(de)直流電壓(ya)(ya)等價地轉換成常用頻(pin)率的(de)(de)交流電壓(ya)(ya),這就是它的(de)(de)原理(li)。
中、小容量逆(ni)(ni)變(bian)器(qi)一般有推挽(wan)逆(ni)(ni)變(bian)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)(lu)、全橋逆(ni)(ni)變(bian)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)(lu)這兩(liang)種逆(ni)(ni)變(bian)橋式(shi)回路(lu)(lu)(lu)(lu)。推挽(wan)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)(lu)能(neng)將升(sheng)壓變(bian)壓器(qi)的(de)中性(xing)插頭(tou)接(jie)(jie)于(yu)正(zheng)電(dian)(dian)(dian)(dian)源(yuan),兩(liang)只功率管交(jiao)替工(gong)作,輸(shu)出(chu)得到交(jiao)流電(dian)(dian)(dian)(dian)力,由(you)于(yu)功率晶體(ti)管共地(di)邊(bian)接(jie)(jie),驅(qu)動及控制電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)(lu)簡單,且變(bian)壓器(qi)具有一定的(de)漏感,因此它(ta)可以(yi)限(xian)制短路(lu)(lu)(lu)(lu)電(dian)(dian)(dian)(dian)流,因而提(ti)高了電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)(lu)的(de)可靠性(xing)。全橋逆(ni)(ni)變(bian)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)(lu)具有續流回路(lu)(lu)(lu)(lu),即使有感性(xing)負載,輸(shu)出(chu)電(dian)(dian)(dian)(dian)壓波形也不會畸(ji)變(bian),但它(ta)必須(xu)采(cai)用專門驅(qu)動電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)(lu)才(cai)能(neng)正(zheng)常(chang)使用。為(wei)防止上、下橋臂發生共同導通,全橋逆(ni)(ni)變(bian)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)(lu)必須(xu)設(she)置(zhi)死(si)區時間,才(cai)不會出(chu)錯,因此它(ta)的(de)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)(lu)結(jie)構較復雜。
光伏逆變器怎么選
1、光伏(fu)逆變器的大(da)小應根據土地或者屋(wu)頂使(shi)用面積來計算,計算時(shi)要考慮到(dao)傾斜角度、支(zhi)架安裝方式等,以盡(jin)量不出現陰影(ying)遮擋為原則。
2、光伏逆(ni)變器MPPT的(de)路(lu)數在很大程度上決(jue)定(ding)(ding)著一個(ge)光伏電(dian)(dian)站(zhan)的(de)發電(dian)(dian)量,而逆(ni)變器輸入(ru)路(lu)數往往決(jue)定(ding)(ding)了一個(ge)光伏電(dian)(dian)站(zhan)是(shi)否(fou)更加容(rong)易進(jin)行配(pei)板設計,因(yin)此購買前(qian),一定(ding)(ding)要想(xiang)好MPPT的(de)路(lu)數要多少。
3、光伏逆變(bian)(bian)(bian)器的散熱方式(shi)有強制風冷(leng)、自(zi)然(ran)冷(leng)卻、水冷(leng)三種(zhong),其(qi)中(zhong)水冷(leng)方式(shi)主要應用(yong)于大型集中(zhong)式(shi)逆變(bian)(bian)(bian)器且應用(yong)較少。從逆變(bian)(bian)(bian)器角度來(lai)看,家庭用(yong)單相(xiang)逆變(bian)(bian)(bian)器功率等級較低(di),散熱較少,選(xuan)擇(ze)強制風冷(leng)即可。