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(jiang)直(zhi)(zhi)流(liu)(liu)電(dian)轉化為交(jiao)(jiao)流(liu)(liu)電(dian)的(de)裝(zhuang)置,若直(zhi)(zhi)流(liu)(liu)電(dian)壓(ya)(ya)(ya)較(jiao)低,則通(tong)過交(jiao)(jiao)流(liu)(liu)變壓(ya)(ya)(ya)器(qi)(qi)升(sheng)壓(ya)(ya)(ya),即得到標準(zhun)交(jiao)(jiao)流(liu)(liu)電(dian)壓(ya)(ya)(ya)和頻(pin)率。大容(rong)量逆變器(qi)(qi)的(de)直(zhi)(zhi)流(liu)(liu)母線電(dian)壓(ya)(ya)(ya)較(jiao)高,交(jiao)(jiao)流(liu)(liu)輸出一般不需要(yao)變壓(ya)(ya)(ya)器(qi)(qi)升(sheng)壓(ya)(ya)(ya)即能(neng)達到220V,在(zai)中、小容(rong)量的(de)逆變器(qi)(qi)中,由于直(zhi)(zhi)流(liu)(liu)電(dian)壓(ya)(ya)(ya)較(jiao)低,就必須設計升(sheng)壓(ya)(ya)(ya)電(dian)路。
光伏逆變器的工作原理
大容量光伏逆(ni)變(bian)(bian)器(qi)是由升(sheng)壓(ya)回路(lu)和逆(ni)變(bian)(bian)橋式回路(lu)構成的,其工作原理很簡單。升(sheng)壓(ya)回路(lu)把(ba)太陽(yang)電(dian)(dian)池的直流電(dian)(dian)壓(ya)升(sheng)壓(ya)到逆(ni)變(bian)(bian)器(qi)輸出控(kong)制(zhi)所需的直流電(dian)(dian)壓(ya),逆(ni)變(bian)(bian)橋式回路(lu)則把(ba)升(sheng)壓(ya)后的直流電(dian)(dian)壓(ya)等價地轉換成常(chang)用頻率(lv)的交流電(dian)(dian)壓(ya),這(zhe)就是它的原理。
中、小容量逆變(bian)器(qi)一般有推挽逆變(bian)電(dian)(dian)(dian)路(lu)(lu)(lu)、全(quan)橋逆變(bian)電(dian)(dian)(dian)路(lu)(lu)(lu)這兩種逆變(bian)橋式回(hui)(hui)路(lu)(lu)(lu)。推挽電(dian)(dian)(dian)路(lu)(lu)(lu)能(neng)將升壓(ya)變(bian)壓(ya)器(qi)的中性(xing)插頭接(jie)于正電(dian)(dian)(dian)源,兩只(zhi)功率管交(jiao)替(ti)工作,輸出得到交(jiao)流電(dian)(dian)(dian)力,由于功率晶(jing)體管共地邊接(jie),驅動及控制(zhi)電(dian)(dian)(dian)路(lu)(lu)(lu)簡單,且變(bian)壓(ya)器(qi)具(ju)有一定的漏感(gan),因此(ci)它(ta)可(ke)以限制(zhi)短路(lu)(lu)(lu)電(dian)(dian)(dian)流,因而提高(gao)了(le)電(dian)(dian)(dian)路(lu)(lu)(lu)的可(ke)靠(kao)性(xing)。全(quan)橋逆變(bian)電(dian)(dian)(dian)路(lu)(lu)(lu)具(ju)有續流回(hui)(hui)路(lu)(lu)(lu),即使有感(gan)性(xing)負載,輸出電(dian)(dian)(dian)壓(ya)波(bo)形(xing)也不會畸變(bian),但它(ta)必須采(cai)用專(zhuan)門驅動電(dian)(dian)(dian)路(lu)(lu)(lu)才能(neng)正常(chang)使用。為防止上、下橋臂發生共同導通,全(quan)橋逆變(bian)電(dian)(dian)(dian)路(lu)(lu)(lu)必須設置死(si)區時間,才不會出錯,因此(ci)它(ta)的電(dian)(dian)(dian)路(lu)(lu)(lu)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(gen)據土(tu)地(di)或者屋頂使用面(mian)積(ji)來計(ji)算(suan),計(ji)算(suan)時要考慮到(dao)傾(qing)斜角度(du)、支架安裝方(fang)式等,以盡量不出現陰(yin)影(ying)遮擋為原則。
2、光(guang)(guang)伏(fu)逆變器MPPT的路(lu)(lu)數在很大程度上決(jue)定著一個光(guang)(guang)伏(fu)電(dian)站的發電(dian)量,而逆變器輸(shu)入路(lu)(lu)數往(wang)(wang)往(wang)(wang)決(jue)定了一個光(guang)(guang)伏(fu)電(dian)站是否更加容(rong)易進(jin)行配板(ban)設計,因此購買前,一定要想好MPPT的路(lu)(lu)數要多少。
3、光(guang)伏逆變(bian)(bian)(bian)器(qi)的(de)散(san)熱方式(shi)(shi)有(you)強制(zhi)風(feng)冷(leng)(leng)、自然冷(leng)(leng)卻、水冷(leng)(leng)三種,其中水冷(leng)(leng)方式(shi)(shi)主要應用于大型集(ji)中式(shi)(shi)逆變(bian)(bian)(bian)器(qi)且應用較少。從(cong)逆變(bian)(bian)(bian)器(qi)角度來看,家庭用單相逆變(bian)(bian)(bian)器(qi)功率等級較低(di),散(san)熱較少,選(xuan)擇強制(zhi)風(feng)冷(leng)(leng)即可。