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)將直流(liu)電(dian)轉化為交(jiao)流(liu)電(dian)的(de)裝置,若直流(liu)電(dian)壓(ya)(ya)較(jiao)低,則通過交(jiao)流(liu)變(bian)壓(ya)(ya)器升(sheng)壓(ya)(ya),即得到(dao)標準交(jiao)流(liu)電(dian)壓(ya)(ya)和頻率。大容量逆(ni)變(bian)器的(de)直流(liu)母線電(dian)壓(ya)(ya)較(jiao)高(gao),交(jiao)流(liu)輸出一般不需要變(bian)壓(ya)(ya)器升(sheng)壓(ya)(ya)即能(neng)達(da)到(dao)220V,在中、小容量的(de)逆(ni)變(bian)器中,由于直流(liu)電(dian)壓(ya)(ya)較(jiao)低,就必須(xu)設計升(sheng)壓(ya)(ya)電(dian)路。
光伏逆變器的工作原理
大(da)容量光伏逆(ni)變器是由升壓(ya)回(hui)(hui)路和逆(ni)變橋(qiao)式(shi)回(hui)(hui)路構成的,其(qi)工作原理很簡單。升壓(ya)回(hui)(hui)路把太陽電池的直流電壓(ya)升壓(ya)到逆(ni)變器輸(shu)出控制所需(xu)的直流電壓(ya),逆(ni)變橋(qiao)式(shi)回(hui)(hui)路則把升壓(ya)后的直流電壓(ya)等價地轉(zhuan)換成常用頻(pin)率的交流電壓(ya),這(zhe)就是它(ta)的原理。
中(zhong)、小容(rong)量逆(ni)變(bian)器一(yi)般有推(tui)挽逆(ni)變(bian)電(dian)(dian)(dian)(dian)(dian)路、全橋(qiao)(qiao)逆(ni)變(bian)電(dian)(dian)(dian)(dian)(dian)路這兩種逆(ni)變(bian)橋(qiao)(qiao)式回(hui)路。推(tui)挽電(dian)(dian)(dian)(dian)(dian)路能將(jiang)升壓變(bian)壓器的中(zhong)性插頭接(jie)于正電(dian)(dian)(dian)(dian)(dian)源,兩只功率管(guan)交替工(gong)作,輸出(chu)得到交流(liu)電(dian)(dian)(dian)(dian)(dian)力,由于功率晶體管(guan)共(gong)(gong)地邊接(jie),驅(qu)動(dong)及控制電(dian)(dian)(dian)(dian)(dian)路簡(jian)單,且(qie)變(bian)壓器具有一(yi)定的漏感,因此它可以(yi)限(xian)制短路電(dian)(dian)(dian)(dian)(dian)流(liu),因而(er)提高了電(dian)(dian)(dian)(dian)(dian)路的可靠性。全橋(qiao)(qiao)逆(ni)變(bian)電(dian)(dian)(dian)(dian)(dian)路具有續流(liu)回(hui)路,即使(shi)有感性負載,輸出(chu)電(dian)(dian)(dian)(dian)(dian)壓波形也(ye)不(bu)會畸變(bian),但它必(bi)須采用(yong)專門驅(qu)動(dong)電(dian)(dian)(dian)(dian)(dian)路才能正常使(shi)用(yong)。為防(fang)止上(shang)、下橋(qiao)(qiao)臂發生共(gong)(gong)同導(dao)通(tong),全橋(qiao)(qiao)逆(ni)變(bian)電(dian)(dian)(dian)(dian)(dian)路必(bi)須設置死(si)區時(shi)間,才不(bu)會出(chu)錯(cuo),因此它的電(dian)(dian)(dian)(dian)(dian)路結構較復雜。
光伏逆變器怎么選
1、光伏逆(ni)變器的大小應根據土地或者屋頂使用面積來計算(suan)(suan),計算(suan)(suan)時要考慮到傾斜(xie)角度、支架安(an)裝方式等,以盡量不出現陰影遮(zhe)擋(dang)為原則。
2、光伏(fu)(fu)(fu)逆變(bian)器(qi)MPPT的路(lu)(lu)數(shu)在(zai)很大程度(du)上決(jue)定(ding)著(zhu)一(yi)個光伏(fu)(fu)(fu)電站的發電量,而逆變(bian)器(qi)輸入(ru)路(lu)(lu)數(shu)往往決(jue)定(ding)了一(yi)個光伏(fu)(fu)(fu)電站是否更加(jia)容易進(jin)行(xing)配板(ban)設計,因此購買前,一(yi)定(ding)要(yao)想好MPPT的路(lu)(lu)數(shu)要(yao)多少(shao)。
3、光伏逆變(bian)器(qi)的散熱方(fang)式有(you)強制風(feng)冷(leng)、自然冷(leng)卻、水冷(leng)三(san)種(zhong),其(qi)中水冷(leng)方(fang)式主要應用(yong)(yong)于大型(xing)集中式逆變(bian)器(qi)且應用(yong)(yong)較(jiao)少(shao)。從逆變(bian)器(qi)角度來看,家庭用(yong)(yong)單相(xiang)逆變(bian)器(qi)功率等級(ji)較(jiao)低,散熱較(jiao)少(shao),選(xuan)擇強制風(feng)冷(leng)即可。