【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(e)定輸出功(gong)(gong)率(lv)(lv)表(biao)示光(guang)伏逆變器向(xiang)負載(zai)供電(dian)的(de)能(neng)力。額(e)定輸出功(gong)(gong)率(lv)(lv)高的(de)光(guang)伏逆變器可以(yi)帶更多的(de)用電(dian)負載(zai)。選用光(guang)伏逆變器時應首先考慮具有足夠的(de)額(e)定功(gong)(gong)率(lv)(lv)，以(yi)滿(man)足最(zui)大(da)負荷下設(she)備(bei)對電(dian)功(gong)(gong)率(lv)(lv)的(de)要求，以(yi)及(ji)系統(tong)的(de)擴容及(ji)一些臨(lin)時負載(zai)的(de)接(jie)入。當用電(dian)設(she)備(bei)以(yi)純電(dian)阻性負載(zai)為生或功(gong)(gong)率(lv)(lv)因數大(da)于(yu)0.9時(shi)，一般選取光(guang)伏逆(ni)變器的額定輸出功(gong)率(lv)比(bi)用電設備總功(gong)率(lv)大10%~15%。

2、輸出電壓的調整性能

輸出(chu)(chu)電(dian)壓(ya)(ya)的(de)調整(zheng)性能(neng)(neng)表(biao)示光(guang)伏(fu)逆變(bian)器輸出(chu)(chu)電(dian)壓(ya)(ya)的(de)穩(wen)壓(ya)(ya)能(neng)(neng)力。一般光(guang)伏(fu)逆變(bian)器產品(pin)都給出(chu)(chu)了當(dang)直流輸入電(dian)壓(ya)(ya)在允許波(bo)動范圍變(bian)動時，該光(guang)伏(fu)逆變(bian)器輸出(chu)(chu)電(dian)壓(ya)(ya)的(de)波(bo)動偏差的(de)百(bai)分率，通常稱為電(dian)壓(ya)(ya)調整(zheng)率。高性能(neng)(neng)的(de)光(guang)伏(fu)逆變(bian)器應同時給出(chu)(chu)當(dang)負載(zai)由零向(xiang)100%變化時，該光伏(fu)逆(ni)變器(qi)輸(shu)出電(dian)壓的(de)偏差百分率(lv)，通常稱為(wei)負載調整率(lv)。性能優良的(de)光伏(fu)逆(ni)變器(qi)的(de)電(dian)壓調整率(lv)應小于等于±3%，負載調整(zheng)率就(jiu)小(xiao)于(yu)等(deng)于(yu)±6%。

3、整機效率

整機(ji)效率(lv)表示(shi)光(guang)伏逆變器自(zi)身功率(lv)損耗的大小(xiao)。容量較大的光(guang)伏逆變器還要給出滿負(fu)荷工(gong)作和低負(fu)荷工(gong)作下的效率(lv)值(zhi)。一般KW級以下的(de)逆變器的(de)效率(lv)應為80%~85%；10KW級的效率應為85%~90%；更大功率(lv)的效率(lv)必(bi)須在90%~95%以(yi)上。逆變器效率高(gao)低對光(guang)(guang)伏發(fa)電(dian)(dian)系統(tong)提高(gao)有效發(fa)電(dian)(dian)量和(he)降(jiang)低發(fa)電(dian)(dian)成本有重要(yao)影響，因此選用(yong)光(guang)(guang)伏逆變器要(yao)盡量進行(xing)比(bi)較，選擇(ze)整機(ji)效率高(gao)一(yi)些的(de)產品(pin)。

4、啟動性能

光伏逆變器應保(bao)證在額定負載下可靠啟(qi)(qi)動(dong)。高性能的光(guang)伏逆變器可以做到連續多次滿負荷(he)啟(qi)(qi)動(dong)而不損壞功率開關器件及其(qi)他電(dian)(dian)路。小型逆變器為了自身安全，有時采用軟(ruan)啟(qi)(qi)動(dong)或限流啟(qi)(qi)動(dong)措施(shi)或電(dian)(dian)路。

光伏產業從歐(ou)洲，澳(ao)洲，到現在的中(zhong)國(guo)已經成(cheng)了(le)熱(re)門行(xing)業，短(duan)短(duan)幾年內國(guo)內光伏逆變器生產廠家如春筍般的誕生，不過(guo)如何選擇太陽能逆變器這個(ge)還(huan)是有一定的標準。

首先(xian)考慮的是光伏電(dian)站(zhan)的規(gui)模，是家庭還(huan)是企業，不過(guo)在國(guo)內組(zu)建太陽能光伏電(dian)站(zhan)還(huan)是比(bi)較少，主(zhu)要是房屋結構條件等限制，無(wu)法安裝太陽能電(dian)池板，廠房和企業還(huan)是很有優勢。小(xiao)型(xing)家庭光伏電(dian)站(zhan)主(zhu)要是針(zhen)對國(guo)外(wai)別墅安裝。

其次考慮的是(shi)效(xiao)率。效(xiao)率說直接點就是(shi)根發(fa)(fa)電量直接掛鉤，所以現在越來(lai)越多的光伏逆變(bian)器(qi)(qi)生產廠家對逆變(bian)器(qi)(qi)的效(xiao)率作為(wei)主要(yao)技(ji)術(shu)優勢來(lai)研發(fa)(fa)。

5、最后要考慮是否可靠

光(guang)(guang)(guang)(guang)伏(fu)并(bing)(bing)網(wang)(wang)發電(dian)(dian)(dian)(dian)系(xi)(xi)統是(shi)將太陽(yang)能(neng)電(dian)(dian)(dian)(dian)池(chi)發出(chu)的(de)(de)(de)直(zhi)(zhi)流電(dian)(dian)(dian)(dian)轉化為(wei)與電(dian)(dian)(dian)(dian)網(wang)(wang)電(dian)(dian)(dian)(dian)壓同頻同相(xiang)的(de)(de)(de)交流電(dian)(dian)(dian)(dian)，并(bing)(bing)且實現既向(xiang)負載供電(dian)(dian)(dian)(dian)，又向(xiang)電(dian)(dian)(dian)(dian)網(wang)(wang)發電(dian)(dian)(dian)(dian)的(de)(de)(de)系(xi)(xi)統。光(guang)(guang)(guang)(guang)伏(fu)并(bing)(bing)網(wang)(wang)發電(dian)(dian)(dian)(dian)系(xi)(xi)統主要由光(guang)(guang)(guang)(guang)伏(fu)陣(zhen)列、并(bing)(bing)網(wang)(wang)逆變器、控制(zhi)器和繼電(dian)(dian)(dian)(dian)保護裝置組(zu)成。光(guang)(guang)(guang)(guang)伏(fu)陣(zhen)列是(shi)光(guang)(guang)(guang)(guang)伏(fu)并(bing)(bing)網(wang)(wang)發電(dian)(dian)(dian)(dian)系(xi)(xi)統的(de)(de)(de)主要部件，由其將接收到的(de)(de)(de)太陽(yang)光(guang)(guang)(guang)(guang)能(neng)直(zhi)(zhi)接轉換為(wei)電(dian)(dian)(dian)(dian)能(neng)。目前工(gong)程上應用的(de)(de)(de)光(guang)(guang)(guang)(guang)伏(fu)陣(zhen)列一般是(shi)由一定數量的(de)(de)(de)晶體硅(gui)太陽(yang)能(neng)電(dian)(dian)(dian)(dian)池(chi)組(zu)件按照系(xi)(xi)統需(xu)要的(de)(de)(de)電(dian)(dian)(dian)(dian)壓的(de)(de)(de)要求串、并(bing)(bing)聯組(zu)成的(de)(de)(de)。