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(neng)將直(zhi)流(liu)(liu)電轉化為交(jiao)流(liu)(liu)電的裝(zhuang)置(zhi),若直(zhi)流(liu)(liu)電壓(ya)(ya)(ya)較(jiao)(jiao)低,則通過(guo)交(jiao)流(liu)(liu)變壓(ya)(ya)(ya)器(qi)(qi)升(sheng)(sheng)壓(ya)(ya)(ya),即得到(dao)標準交(jiao)流(liu)(liu)電壓(ya)(ya)(ya)和頻率。大容量(liang)逆變器(qi)(qi)的直(zhi)流(liu)(liu)母線電壓(ya)(ya)(ya)較(jiao)(jiao)高,交(jiao)流(liu)(liu)輸出一般不(bu)需要(yao)變壓(ya)(ya)(ya)器(qi)(qi)升(sheng)(sheng)壓(ya)(ya)(ya)即能(neng)達到(dao)220V,在(zai)中(zhong)、小容量(liang)的逆變器(qi)(qi)中(zhong),由(you)于直(zhi)流(liu)(liu)電壓(ya)(ya)(ya)較(jiao)(jiao)低,就必須設計升(sheng)(sheng)壓(ya)(ya)(ya)電路(lu)。
光伏逆變器的工作原理
大(da)容量光伏逆(ni)(ni)(ni)變器是(shi)由升(sheng)壓(ya)回路和逆(ni)(ni)(ni)變橋式回路構成(cheng)的,其(qi)工作原理(li)很(hen)簡單(dan)。升(sheng)壓(ya)回路把太陽電(dian)池的直流電(dian)壓(ya)升(sheng)壓(ya)到逆(ni)(ni)(ni)變器輸出控制所需的直流電(dian)壓(ya),逆(ni)(ni)(ni)變橋式回路則把升(sheng)壓(ya)后的直流電(dian)壓(ya)等價地轉換成(cheng)常用頻率的交流電(dian)壓(ya),這就是(shi)它的原理(li)。
中、小容(rong)量逆變(bian)(bian)器(qi)一般有(you)(you)推(tui)挽(wan)逆變(bian)(bian)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)(lu)、全橋(qiao)逆變(bian)(bian)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)(lu)這兩種逆變(bian)(bian)橋(qiao)式回(hui)路(lu)(lu)(lu)(lu)。推(tui)挽(wan)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)(lu)能(neng)將升壓(ya)(ya)變(bian)(bian)壓(ya)(ya)器(qi)的(de)中性(xing)插頭接(jie)(jie)于(yu)正電(dian)(dian)(dian)(dian)源,兩只功(gong)率管交替(ti)工(gong)作,輸出(chu)得到(dao)交流電(dian)(dian)(dian)(dian)力,由于(yu)功(gong)率晶體管共(gong)地(di)邊接(jie)(jie),驅動及控(kong)制電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)(lu)簡單,且變(bian)(bian)壓(ya)(ya)器(qi)具有(you)(you)一定(ding)的(de)漏感(gan)(gan),因此它可以(yi)限制短路(lu)(lu)(lu)(lu)電(dian)(dian)(dian)(dian)流,因而(er)提(ti)高了電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)(lu)的(de)可靠(kao)性(xing)。全橋(qiao)逆變(bian)(bian)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)(lu)具有(you)(you)續流回(hui)路(lu)(lu)(lu)(lu),即使有(you)(you)感(gan)(gan)性(xing)負載,輸出(chu)電(dian)(dian)(dian)(dian)壓(ya)(ya)波形(xing)也不會畸(ji)變(bian)(bian),但它必(bi)須采用專門驅動電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)(lu)才能(neng)正常(chang)使用。為防止上、下橋(qiao)臂發(fa)生共(gong)同導(dao)通,全橋(qiao)逆變(bian)(bian)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)(lu)必(bi)須設置死區時間(jian),才不會出(chu)錯,因此它的(de)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)(lu)結構較復雜。
光伏逆變器怎么選
1、光伏(fu)逆變器(qi)的大(da)小應(ying)根(gen)據土地或者屋頂使用面積來計算,計算時要考慮到傾斜角(jiao)度、支架安裝方式等,以(yi)盡量不出現陰影遮擋(dang)為原(yuan)則。
2、光伏逆(ni)變(bian)(bian)器MPPT的(de)路(lu)(lu)數(shu)(shu)在很大程度(du)上決定(ding)著一個光伏電(dian)站的(de)發(fa)電(dian)量,而逆(ni)變(bian)(bian)器輸入路(lu)(lu)數(shu)(shu)往往決定(ding)了一個光伏電(dian)站是否(fou)更加容易進行配板設計,因此購(gou)買前,一定(ding)要(yao)想好(hao)MPPT的(de)路(lu)(lu)數(shu)(shu)要(yao)多少。
3、光伏逆(ni)(ni)變(bian)器(qi)的散熱(re)方(fang)式(shi)有強制風冷(leng)、自然冷(leng)卻、水冷(leng)三種(zhong),其中水冷(leng)方(fang)式(shi)主要應(ying)用(yong)于大型(xing)集中式(shi)逆(ni)(ni)變(bian)器(qi)且應(ying)用(yong)較(jiao)少。從逆(ni)(ni)變(bian)器(qi)角度(du)來看,家庭用(yong)單相(xiang)逆(ni)(ni)變(bian)器(qi)功(gong)率等級較(jiao)低,散熱(re)較(jiao)少,選擇強制風冷(leng)即(ji)可。