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)流(liu)電(dian)轉化為交(jiao)流(liu)電(dian)的(de)裝置,若直(zhi)流(liu)電(dian)壓(ya)(ya)較低(di),則通過交(jiao)流(liu)變壓(ya)(ya)器升壓(ya)(ya),即(ji)得到(dao)標準交(jiao)流(liu)電(dian)壓(ya)(ya)和頻率。大(da)容(rong)量逆變器的(de)直(zhi)流(liu)母線電(dian)壓(ya)(ya)較高,交(jiao)流(liu)輸出一般不需要變壓(ya)(ya)器升壓(ya)(ya)即(ji)能達(da)到(dao)220V,在中、小容(rong)量的(de)逆變器中,由于直(zhi)流(liu)電(dian)壓(ya)(ya)較低(di),就(jiu)必須設計升壓(ya)(ya)電(dian)路。
光伏逆變器的工作原理
大容量(liang)光伏逆(ni)變器(qi)是(shi)由(you)升(sheng)(sheng)壓(ya)(ya)(ya)(ya)回路和逆(ni)變橋式(shi)回路構成(cheng)(cheng)的(de),其工作原理很簡單(dan)。升(sheng)(sheng)壓(ya)(ya)(ya)(ya)回路把太陽電(dian)池的(de)直流(liu)電(dian)壓(ya)(ya)(ya)(ya)升(sheng)(sheng)壓(ya)(ya)(ya)(ya)到逆(ni)變器(qi)輸出控制所需的(de)直流(liu)電(dian)壓(ya)(ya)(ya)(ya),逆(ni)變橋式(shi)回路則把升(sheng)(sheng)壓(ya)(ya)(ya)(ya)后的(de)直流(liu)電(dian)壓(ya)(ya)(ya)(ya)等價(jia)地轉換成(cheng)(cheng)常用頻(pin)率(lv)的(de)交流(liu)電(dian)壓(ya)(ya)(ya)(ya),這就(jiu)是(shi)它的(de)原理。
中、小容量逆(ni)變(bian)(bian)器(qi)一(yi)(yi)般(ban)有(you)推挽逆(ni)變(bian)(bian)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)、全橋(qiao)(qiao)逆(ni)變(bian)(bian)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)這兩種逆(ni)變(bian)(bian)橋(qiao)(qiao)式回(hui)路(lu)(lu)(lu)。推挽電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)能(neng)將升壓(ya)變(bian)(bian)壓(ya)器(qi)的(de)中性(xing)(xing)插頭(tou)接(jie)于正電(dian)(dian)(dian)(dian)源,兩只功率管(guan)交(jiao)替(ti)工(gong)作,輸出(chu)(chu)得(de)到(dao)交(jiao)流電(dian)(dian)(dian)(dian)力,由于功率晶體管(guan)共地邊接(jie),驅(qu)動及控(kong)制電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)簡單,且變(bian)(bian)壓(ya)器(qi)具有(you)一(yi)(yi)定的(de)漏感,因此(ci)它可(ke)以(yi)限(xian)制短(duan)路(lu)(lu)(lu)電(dian)(dian)(dian)(dian)流,因而提(ti)高(gao)了電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)的(de)可(ke)靠性(xing)(xing)。全橋(qiao)(qiao)逆(ni)變(bian)(bian)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)具有(you)續(xu)流回(hui)路(lu)(lu)(lu),即(ji)使(shi)有(you)感性(xing)(xing)負載,輸出(chu)(chu)電(dian)(dian)(dian)(dian)壓(ya)波形也不會(hui)畸(ji)變(bian)(bian),但它必須采用(yong)專(zhuan)門驅(qu)動電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)才能(neng)正常(chang)使(shi)用(yong)。為防止上、下橋(qiao)(qiao)臂發生共同(tong)導通,全橋(qiao)(qiao)逆(ni)變(bian)(bian)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)必須設置死區時間,才不會(hui)出(chu)(chu)錯(cuo),因此(ci)它的(de)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)結構(gou)較復雜。
光伏逆變器怎么選
1、光伏逆變器(qi)的大小(xiao)應根據土地(di)或(huo)者屋頂(ding)使用面積來計(ji)(ji)算(suan),計(ji)(ji)算(suan)時要(yao)考(kao)慮到傾斜角度(du)、支架安裝方(fang)式等(deng),以盡量不出現(xian)陰影遮擋為原則。
2、光伏逆變(bian)器(qi)MPPT的(de)路(lu)(lu)數(shu)(shu)在很大程度上(shang)決(jue)定著一個(ge)(ge)光伏電(dian)站的(de)發電(dian)量,而逆變(bian)器(qi)輸入路(lu)(lu)數(shu)(shu)往(wang)往(wang)決(jue)定了一個(ge)(ge)光伏電(dian)站是否(fou)更(geng)加容(rong)易進行配板設計,因此購買前,一定要(yao)想(xiang)好MPPT的(de)路(lu)(lu)數(shu)(shu)要(yao)多(duo)少。
3、光(guang)伏逆(ni)變器的散熱方(fang)式(shi)有強制風冷(leng)、自然冷(leng)卻、水冷(leng)三種,其(qi)中(zhong)水冷(leng)方(fang)式(shi)主要應用(yong)于(yu)大型集中(zhong)式(shi)逆(ni)變器且(qie)應用(yong)較(jiao)少。從逆(ni)變器角度來看,家庭(ting)用(yong)單(dan)相逆(ni)變器功率等級較(jiao)低,散熱較(jiao)少,選(xuan)擇(ze)強制風冷(leng)即可。