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)電(dian)(dian)(dian)(dian)轉化為交流(liu)電(dian)(dian)(dian)(dian)的(de)裝置(zhi),若直(zhi)流(liu)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)較低,則通(tong)過交流(liu)變(bian)(bian)壓(ya)(ya)(ya)器(qi)升(sheng)壓(ya)(ya)(ya),即得到標準交流(liu)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)和頻率。大容量逆(ni)變(bian)(bian)器(qi)的(de)直(zhi)流(liu)母(mu)線電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)較高,交流(liu)輸出一般不(bu)需要變(bian)(bian)壓(ya)(ya)(ya)器(qi)升(sheng)壓(ya)(ya)(ya)即能(neng)達到220V,在(zai)中(zhong)、小容量的(de)逆(ni)變(bian)(bian)器(qi)中(zhong),由于直(zhi)流(liu)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)較低,就(jiu)必須設計升(sheng)壓(ya)(ya)(ya)電(dian)(dian)(dian)(dian)路。
光伏逆變器的工作原理
大容量光伏逆變(bian)(bian)器(qi)是由升壓(ya)回路和逆變(bian)(bian)橋(qiao)式回路構成(cheng)的,其(qi)工作原(yuan)理很簡(jian)單。升壓(ya)回路把(ba)太陽電(dian)池(chi)的直(zhi)流(liu)(liu)電(dian)壓(ya)升壓(ya)到逆變(bian)(bian)器(qi)輸(shu)出控(kong)制所(suo)需的直(zhi)流(liu)(liu)電(dian)壓(ya),逆變(bian)(bian)橋(qiao)式回路則把(ba)升壓(ya)后(hou)的直(zhi)流(liu)(liu)電(dian)壓(ya)等(deng)價地轉換成(cheng)常(chang)用頻(pin)率的交流(liu)(liu)電(dian)壓(ya),這就(jiu)是它的原(yuan)理。
中、小容量逆(ni)變(bian)(bian)器(qi)(qi)一般有推挽逆(ni)變(bian)(bian)電(dian)路、全(quan)橋(qiao)逆(ni)變(bian)(bian)電(dian)路這兩(liang)種逆(ni)變(bian)(bian)橋(qiao)式回路。推挽電(dian)路能(neng)將(jiang)升壓(ya)變(bian)(bian)壓(ya)器(qi)(qi)的(de)(de)中性插頭(tou)接(jie)于正電(dian)源,兩(liang)只(zhi)功率管交替工(gong)作(zuo),輸出(chu)(chu)得到交流(liu)電(dian)力(li),由于功率晶(jing)體管共地邊(bian)接(jie),驅(qu)動及控制(zhi)電(dian)路簡單,且變(bian)(bian)壓(ya)器(qi)(qi)具有一定的(de)(de)漏感,因此它(ta)可(ke)以限制(zhi)短路電(dian)流(liu),因而提高了電(dian)路的(de)(de)可(ke)靠(kao)性。全(quan)橋(qiao)逆(ni)變(bian)(bian)電(dian)路具有續流(liu)回路,即使有感性負載,輸出(chu)(chu)電(dian)壓(ya)波(bo)形(xing)也不會(hui)畸變(bian)(bian),但它(ta)必須采用專門驅(qu)動電(dian)路才(cai)能(neng)正常使用。為防止上、下橋(qiao)臂發生共同導通,全(quan)橋(qiao)逆(ni)變(bian)(bian)電(dian)路必須設(she)置死(si)區時間(jian),才(cai)不會(hui)出(chu)(chu)錯,因此它(ta)的(de)(de)電(dian)路結構較復雜。
光伏逆變器怎么選
1、光伏逆變器(qi)的大小應根據土地或者屋頂使用面(mian)積來計算,計算時要考慮到傾斜角度、支架安裝(zhuang)方式等,以盡(jin)量不出現陰影遮擋為原則。
2、光(guang)伏逆(ni)(ni)變(bian)器(qi)(qi)MPPT的(de)路數在很大程(cheng)度上決定著一個(ge)光(guang)伏電(dian)(dian)站(zhan)的(de)發電(dian)(dian)量(liang),而逆(ni)(ni)變(bian)器(qi)(qi)輸入路數往(wang)往(wang)決定了一個(ge)光(guang)伏電(dian)(dian)站(zhan)是否(fou)更(geng)加容易(yi)進行配(pei)板設計,因此購買前,一定要想好MPPT的(de)路數要多少(shao)。
3、光伏(fu)逆(ni)(ni)變器的散熱(re)方式(shi)有強(qiang)制(zhi)風冷(leng)(leng)、自然冷(leng)(leng)卻、水(shui)冷(leng)(leng)三種(zhong),其(qi)中水(shui)冷(leng)(leng)方式(shi)主要應用(yong)于大型集中式(shi)逆(ni)(ni)變器且應用(yong)較(jiao)少。從逆(ni)(ni)變器角度(du)來看(kan),家庭用(yong)單相逆(ni)(ni)變器功率(lv)等級(ji)較(jiao)低,散熱(re)較(jiao)少,選(xuan)擇強(qiang)制(zhi)風冷(leng)(leng)即可。