光伏逆(ni)變(bian)器的結構原理(li)

逆變(bian)(bian)器是(shi)一(yi)種由半導(dao)體器件組成(cheng)的電力調整裝置，主要用于(yu)把直流電力轉換(huan)成(cheng)交流電力。一(yi)般由升(sheng)壓回路和逆變(bian)(bian)橋式(shi)回路構成(cheng)。

升(sheng)(sheng)壓(ya)回(hui)路(lu)把太陽(yang)電(dian)(dian)(dian)(dian)池的(de)直流(liu)(liu)電(dian)(dian)(dian)(dian)壓(ya)升(sheng)(sheng)壓(ya)到逆(ni)(ni)變(bian)器輸(shu)(shu)出(chu)控制所(suo)需的(de)直流(liu)(liu)電(dian)(dian)(dian)(dian)壓(ya)；逆(ni)(ni)變(bian)橋(qiao)式回(hui)路(lu)則把升(sheng)(sheng)壓(ya)后(hou)的(de)直流(liu)(liu)電(dian)(dian)(dian)(dian)壓(ya)等(deng)價地(di)(di)轉換成(cheng)常用(yong)(yong)頻率(lv)的(de)交流(liu)(liu)電(dian)(dian)(dian)(dian)壓(ya)。逆(ni)(ni)變(bian)器主要由晶體(ti)管等(deng)開關元件(jian)構(gou)成(cheng)，通過有規則地(di)(di)讓開關元件(jian)重復(fu)開-關（ON-OFF），使(shi)直流(liu)(liu)輸(shu)(shu)入變(bian)成(cheng)交流(liu)(liu)輸(shu)(shu)出(chu)。當然(ran)，光伏逆(ni)(ni)變(bian)器價格表(biao)，這樣單純地(di)(di)由開和關回(hui)路(lu)產生的(de)逆(ni)(ni)變(bian)器輸(shu)(shu)出(chu)波形并不實用(yong)(yong)。

光(guang)伏逆變器的(de)功能(neng)有哪些(xie)呢？

大功率跟蹤控制功能

太(tai)(tai)陽(yang)電(dian)(dian)池(chi)組(zu)件的輸出是隨(sui)太(tai)(tai)陽(yang)輻(fu)(fu)射強度(du)和太(tai)(tai)陽(yang)電(dian)(dian)池(chi)組(zu)件自身溫度(du)（芯片溫度(du)）而(er)(er)變(bian)(bian)(bian)化(hua)的。另外(wai)由于太(tai)(tai)陽(yang)電(dian)(dian)池(chi)組(zu)件具有電(dian)(dian)壓隨(sui)電(dian)(dian)流增大而(er)(er)下降的特(te)(te)性，因此存在(zai)能獲(huo)(huo)取(qu)功(gong)率的工作(zuo)點(dian)。太(tai)(tai)陽(yang)輻(fu)(fu)射強度(du)是變(bian)(bian)(bian)化(hua)著(zhu)的，光(guang)伏(fu)逆變(bian)(bian)(bian)器生產(chan)廠家，顯然工作(zuo)點(dian)也是在(zai)變(bian)(bian)(bian)化(hua)的。相對于這(zhe)些變(bian)(bian)(bian)化(hua)，始終(zhong)讓太(tai)(tai)陽(yang)電(dian)(dian)池(chi)組(zu)件的工作(zuo)點(dian)處于功(gong)率點(dian)，光(guang)伏(fu)逆變(bian)(bian)(bian)器品牌，系統始終(zhong)從太(tai)(tai)陽(yang)電(dian)(dian)池(chi)組(zu)件獲(huo)(huo)取(qu)功(gong)率輸出，這(zhe)種控制(zhi)就是功(gong)率跟蹤控制(zhi)。太(tai)(tai)陽(yang)能發電(dian)(dian)系統用的逆變(bian)(bian)(bian)器的特(te)(te)點(dian)就是包括(kuo)了功(gong)率點(dian)跟蹤（MPPT）這(zhe)一功(gong)能。

很大功(gong)率點(dian)（MPPT）的(de)技術來(lai)從(cong)太陽能板抽取大可能的(de)功(gong)率。太陽能電(dian)(dian)(dian)池的(de)太陽輻照度(du)、溫(wen)度(du)及總(zong)電(dian)(dian)(dian)阻之間(jian)有(you)復雜(za)的(de)關系，安徽光伏(fu)逆(ni)變(bian)器(qi)(qi)(qi)，因此輸出效率會(hui)有(you)非線(xian)性(xing)的(de)變(bian)化，稱(cheng)為(wei)電(dian)(dian)(dian)流(liu)-電(dian)(dian)(dian)壓曲線(xian)（I-V curve）。太陽能并(bing)網(wang)逆(ni)變(bian)器(qi)(qi)(qi)是將電(dian)(dian)(dian)能反饋到電(dian)(dian)(dian)網(wang)，若電(dian)(dian)(dian)網(wang)斷(duan)電(dian)(dian)(dian)時，需快速的(de)切斷(duan)供(gong)電(dian)(dian)(dian)給電(dian)(dian)(dian)網(wang)的(de)線(xian)路，這是美國(guo)國(guo)家電(dian)(dian)(dian)氣規范（NEC）的(de)要求(qiu)，以確(que)保在斷(duan)電(dian)(dian)(dian)時，并(bing)網(wang)逆(ni)變(bian)器(qi)(qi)(qi)也會(hui)關閉(bi)，避免傷(shang)害維修電(dian)(dian)(dian)網(wang)的(de)人員。逆(ni)變(bian)器(qi)(qi)(qi)為(wei)光伏(fu)系統的(de)一部(bu)分，又(you)被叫做電(dian)(dian)(dian)源調整(zheng)器(qi)(qi)(qi)、功(gong)率調節(jie)器(qi)(qi)(qi)。