【光伏逆變器技術指標】太陽能發電系統中光伏逆變器應該如何選擇?

1、額定輸出功率

額定輸出功(gong)(gong)率(lv)表示光伏(fu)逆變器向(xiang)負(fu)載供電(dian)的(de)能力。額定輸出功(gong)(gong)率(lv)高的(de)光伏(fu)逆變器可以(yi)(yi)帶更(geng)多的(de)用(yong)電(dian)負(fu)載。選用(yong)光伏(fu)逆變器時(shi)應首先考慮具有足夠(gou)的(de)額定功(gong)(gong)率(lv)，以(yi)(yi)滿足最(zui)大負(fu)荷(he)下設備對電(dian)功(gong)(gong)率(lv)的(de)要求，以(yi)(yi)及系統(tong)的(de)擴容及一些臨時(shi)負(fu)載的(de)接入(ru)。當用(yong)電(dian)設備以(yi)(yi)純(chun)電(dian)阻性負(fu)載為生或功(gong)(gong)率(lv)因數大于0.9時，一般(ban)選取光伏逆變器的(de)額(e)定輸出功(gong)(gong)率比(bi)用電設備總功(gong)(gong)率大10%~15%。

2、輸出電壓的調整性能

輸(shu)(shu)(shu)出(chu)電(dian)壓(ya)(ya)的調整(zheng)性能(neng)表示光伏逆變(bian)器輸(shu)(shu)(shu)出(chu)電(dian)壓(ya)(ya)的穩壓(ya)(ya)能(neng)力。一般光伏逆變(bian)器產品都給出(chu)了當(dang)直流輸(shu)(shu)(shu)入(ru)電(dian)壓(ya)(ya)在允許波動(dong)范圍變(bian)動(dong)時(shi)，該光伏逆變(bian)器輸(shu)(shu)(shu)出(chu)電(dian)壓(ya)(ya)的波動(dong)偏差的百分(fen)率，通常稱為電(dian)壓(ya)(ya)調整(zheng)率。高性能(neng)的光伏逆變(bian)器應同時(shi)給出(chu)當(dang)負(fu)載由零向(xiang)100%變(bian)(bian)化時，該光伏逆(ni)變(bian)(bian)器輸出電壓的偏(pian)差百分率(lv)，通(tong)常稱(cheng)為負(fu)載調(diao)整率(lv)。性能優(you)良的光伏逆(ni)變(bian)(bian)器的電壓調(diao)整率(lv)應小(xiao)于等于±3%，負載調整率就小(xiao)于等于±6%。

3、整機效率

整機(ji)效(xiao)(xiao)率(lv)表示光(guang)伏逆變(bian)器自身功率(lv)損耗的大小(xiao)。容量較大的光(guang)伏逆變(bian)器還要給出滿負荷工作(zuo)和(he)低(di)負荷工作(zuo)下(xia)的效(xiao)(xiao)率(lv)值。一(yi)般KW級以下的逆變器(qi)的效率應為80%~85%；10KW級的效率應(ying)為85%~90%；更大功率的(de)效率必(bi)須在90%~95%以(yi)上。逆變(bian)器(qi)效率高(gao)低對光伏(fu)發(fa)電(dian)系統提高(gao)有效發(fa)電(dian)量(liang)(liang)和降低發(fa)電(dian)成本有重要影(ying)響(xiang)，因此選用光伏(fu)逆變(bian)器(qi)要盡量(liang)(liang)進行(xing)比較，選擇整機效率高(gao)一些的產品。

4、啟動性能

光伏逆變器應保證在額定負(fu)載下(xia)可(ke)靠啟(qi)動(dong)。高性能的(de)光(guang)伏(fu)逆變器可(ke)以做到連續多次滿(man)負(fu)荷啟(qi)動(dong)而不損(sun)壞功率開(kai)關器件及其他電(dian)(dian)路。小型逆變器為了自(zi)身安(an)全，有(you)時采(cai)用軟啟(qi)動(dong)或限流(liu)啟(qi)動(dong)措施(shi)或電(dian)(dian)路。

光伏(fu)產業(ye)從歐洲，澳洲，到現在(zai)的中國已經(jing)成了熱門行業(ye)，短短幾年內(nei)國內(nei)光伏(fu)逆變器生產廠家如(ru)春筍般的誕(dan)生，不過如(ru)何選(xuan)擇太陽能逆變器這個還(huan)是有一定的標準(zhun)。

首先考慮的是(shi)(shi)(shi)光伏電站(zhan)的規模，是(shi)(shi)(shi)家庭(ting)還是(shi)(shi)(shi)企業，不過(guo)在國(guo)內組建太陽(yang)能(neng)(neng)光伏電站(zhan)還是(shi)(shi)(shi)比較少(shao)，主(zhu)要(yao)是(shi)(shi)(shi)房(fang)屋結(jie)構條(tiao)件(jian)等限制，無法(fa)安裝太陽(yang)能(neng)(neng)電池(chi)板(ban)，廠房(fang)和企業還是(shi)(shi)(shi)很有(you)優勢。小型家庭(ting)光伏電站(zhan)主(zhu)要(yao)是(shi)(shi)(shi)針對國(guo)外(wai)別(bie)墅安裝。

其次考(kao)慮的是效率(lv)。效率(lv)說直接點就是根發(fa)電(dian)量直接掛(gua)鉤，所以現在越來(lai)越多的光(guang)伏逆(ni)變器生產(chan)廠家對逆(ni)變器的效率(lv)作為主要(yao)技術(shu)優(you)勢(shi)來(lai)研發(fa)。

5、最后要考慮是否可靠

光(guang)伏并(bing)網(wang)(wang)發電(dian)(dian)(dian)(dian)(dian)(dian)系(xi)統是將太(tai)陽能(neng)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)發出(chu)的(de)(de)直流電(dian)(dian)(dian)(dian)(dian)(dian)轉化為與電(dian)(dian)(dian)(dian)(dian)(dian)網(wang)(wang)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)同頻同相(xiang)的(de)(de)交流電(dian)(dian)(dian)(dian)(dian)(dian)，并(bing)且實現既向負載供(gong)電(dian)(dian)(dian)(dian)(dian)(dian)，又向電(dian)(dian)(dian)(dian)(dian)(dian)網(wang)(wang)發電(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)系(xi)統。光(guang)伏并(bing)網(wang)(wang)發電(dian)(dian)(dian)(dian)(dian)(dian)系(xi)統主(zhu)要由光(guang)伏陣(zhen)列(lie)、并(bing)網(wang)(wang)逆(ni)變器(qi)、控(kong)制器(qi)和繼電(dian)(dian)(dian)(dian)(dian)(dian)保(bao)護裝置組(zu)成(cheng)。光(guang)伏陣(zhen)列(lie)是光(guang)伏并(bing)網(wang)(wang)發電(dian)(dian)(dian)(dian)(dian)(dian)系(xi)統的(de)(de)主(zhu)要部件，由其將接(jie)收到的(de)(de)太(tai)陽光(guang)能(neng)直接(jie)轉換為電(dian)(dian)(dian)(dian)(dian)(dian)能(neng)。目(mu)前工程上應(ying)用的(de)(de)光(guang)伏陣(zhen)列(lie)一(yi)般(ban)是由一(yi)定(ding)數量的(de)(de)晶體硅太(tai)陽能(neng)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)組(zu)件按照系(xi)統需要的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)的(de)(de)要求串、并(bing)聯組(zu)成(cheng)的(de)(de)。