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)直流電(dian)(dian)(dian)轉化為交流電(dian)(dian)(dian)的裝置,若(ruo)直流電(dian)(dian)(dian)壓(ya)較低,則(ze)通過交流變(bian)壓(ya)器(qi)(qi)升(sheng)(sheng)壓(ya),即(ji)得到標準交流電(dian)(dian)(dian)壓(ya)和頻(pin)率。大(da)容(rong)量(liang)逆(ni)變(bian)器(qi)(qi)的直流母線電(dian)(dian)(dian)壓(ya)較高,交流輸出一般不需要變(bian)壓(ya)器(qi)(qi)升(sheng)(sheng)壓(ya)即(ji)能(neng)達(da)到220V,在中、小容(rong)量(liang)的逆(ni)變(bian)器(qi)(qi)中,由于直流電(dian)(dian)(dian)壓(ya)較低,就(jiu)必須設計(ji)升(sheng)(sheng)壓(ya)電(dian)(dian)(dian)路。
光伏逆變器的工作原理
大容量光伏逆變(bian)器(qi)是由升(sheng)壓(ya)回(hui)(hui)路和逆變(bian)橋(qiao)式(shi)回(hui)(hui)路構成(cheng)(cheng)的(de)(de),其(qi)工作原理很(hen)簡(jian)單。升(sheng)壓(ya)回(hui)(hui)路把太陽電(dian)(dian)池(chi)的(de)(de)直流電(dian)(dian)壓(ya)升(sheng)壓(ya)到逆變(bian)器(qi)輸出控制所需的(de)(de)直流電(dian)(dian)壓(ya),逆變(bian)橋(qiao)式(shi)回(hui)(hui)路則(ze)把升(sheng)壓(ya)后的(de)(de)直流電(dian)(dian)壓(ya)等價地轉(zhuan)換成(cheng)(cheng)常用頻率的(de)(de)交流電(dian)(dian)壓(ya),這就是它的(de)(de)原理。
中、小容量逆變(bian)器(qi)一般(ban)有推挽逆變(bian)電(dian)(dian)(dian)路(lu)(lu)(lu)、全(quan)橋(qiao)逆變(bian)電(dian)(dian)(dian)路(lu)(lu)(lu)這兩(liang)種逆變(bian)橋(qiao)式回(hui)路(lu)(lu)(lu)。推挽電(dian)(dian)(dian)路(lu)(lu)(lu)能(neng)將升壓變(bian)壓器(qi)的(de)中性(xing)插頭(tou)接(jie)于(yu)正電(dian)(dian)(dian)源,兩(liang)只(zhi)功率管交替工(gong)作,輸(shu)出得(de)到(dao)交流(liu)(liu)電(dian)(dian)(dian)力,由于(yu)功率晶體管共(gong)地邊接(jie),驅動(dong)及控制(zhi)(zhi)電(dian)(dian)(dian)路(lu)(lu)(lu)簡(jian)單,且變(bian)壓器(qi)具(ju)有一定的(de)漏感,因(yin)此(ci)它(ta)可(ke)以限制(zhi)(zhi)短(duan)路(lu)(lu)(lu)電(dian)(dian)(dian)流(liu)(liu),因(yin)而(er)提高了電(dian)(dian)(dian)路(lu)(lu)(lu)的(de)可(ke)靠性(xing)。全(quan)橋(qiao)逆變(bian)電(dian)(dian)(dian)路(lu)(lu)(lu)具(ju)有續流(liu)(liu)回(hui)路(lu)(lu)(lu),即使(shi)有感性(xing)負載,輸(shu)出電(dian)(dian)(dian)壓波形也不會畸變(bian),但它(ta)必須采用專門(men)驅動(dong)電(dian)(dian)(dian)路(lu)(lu)(lu)才(cai)能(neng)正常(chang)使(shi)用。為(wei)防止上、下橋(qiao)臂發生共(gong)同導通,全(quan)橋(qiao)逆變(bian)電(dian)(dian)(dian)路(lu)(lu)(lu)必須設(she)置死(si)區(qu)時間,才(cai)不會出錯,因(yin)此(ci)它(ta)的(de)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(ni)變器(qi)的大小(xiao)應根據土地(di)或(huo)者屋頂使(shi)用面(mian)積來(lai)計算,計算時要考(kao)慮到傾斜角度、支架安(an)裝方式等,以盡量不出現(xian)陰影遮擋為原則。
2、光伏(fu)逆變(bian)器(qi)MPPT的(de)路數在很(hen)大程度上決(jue)定(ding)著一(yi)個光伏(fu)電站的(de)發電量,而逆變(bian)器(qi)輸入路數往(wang)往(wang)決(jue)定(ding)了一(yi)個光伏(fu)電站是否更加容易(yi)進行配板(ban)設(she)計,因此購買(mai)前(qian),一(yi)定(ding)要想好MPPT的(de)路數要多(duo)少。
3、光(guang)伏逆變(bian)(bian)器的散熱方式有強(qiang)制(zhi)(zhi)風冷(leng)、自然(ran)冷(leng)卻、水(shui)冷(leng)三種,其中水(shui)冷(leng)方式主要應(ying)用(yong)于(yu)大型集中式逆變(bian)(bian)器且應(ying)用(yong)較(jiao)少(shao)。從逆變(bian)(bian)器角度來看,家庭用(yong)單相(xiang)逆變(bian)(bian)器功率等級較(jiao)低,散熱較(jiao)少(shao),選擇(ze)強(qiang)制(zhi)(zhi)風冷(leng)即可(ke)。