一、儲能變流器是雙向還是單向

儲能變流器（PCS）又稱儲(chu)能(neng)(neng)逆變器，是連接儲(chu)能(neng)(neng)電(dian)池系統和(he)電(dian)網的雙向電(dian)流(liu)(liu)可控轉換裝置，能(neng)(neng)夠在(zai)電(dian)網和(he)儲(chu)能(neng)(neng)系統間精確快(kuai)速地調節電(dian)壓、頻率(lv)、功率(lv)，實(shi)現恒功率(lv)恒流(liu)(liu)充(chong)放電(dian)以及平滑波(bo)動性電(dian)源輸出。

儲能(neng)變(bian)(bian)流器不僅能(neng)滿(man)足傳統并網變(bian)(bian)流器對直流電(dian)(dian)轉換為交(jiao)流電(dian)(dian)的逆變(bian)(bian)要求(qiu)，還可(ke)滿(man)足儲能(neng)系統“充電(dian)(dian)+放(fang)電(dian)(dian)”帶來的雙(shuang)向(xiang)變(bian)(bian)流需(xu)求(qiu)，具有(you)對電(dian)(dian)池充電(dian)(dian)和(he)放(fang)電(dian)(dian)功能(neng)，可(ke)用于光伏、風力(li)發(fa)電(dian)(dian)功率平滑、削峰填谷(gu)、微型(xing)電(dian)(dian)網等多種場合。

并網(wang)模(mo)式下，在(zai)(zai)負(fu)荷低谷期，儲能(neng)變(bian)流(liu)(liu)器(qi)把電(dian)網(wang)的交流(liu)(liu)電(dian)整(zheng)流(liu)(liu)成直流(liu)(liu)電(dian)給電(dian)池組(zu)充電(dian)，在(zai)(zai)負(fu)荷高峰(feng)期，儲能(neng)變(bian)流(liu)(liu)器(qi)把電(dian)池組(zu)中的直流(liu)(liu)電(dian)逆變(bian)成交流(liu)(liu)電(dian)反(fan)送到電(dian)網(wang)中。

離網(wang)模式(shi)下(xia)，儲能變流器與主(zhu)電網(wang)脫開，給本地的部分(fen)負(fu)荷提(ti)供(gong)滿(man)足電網(wang)電能質量要求的電能。

二、雙向儲能變流器的工作模式有哪些

雙向儲能變流器pcs的(de)工(gong)作模(mo)式分為并網模(mo)式、離網模(mo)式和混合模(mo)式。

1、并網模式

并(bing)網(wang)模(mo)式下(xia)包括(kuo)充(chong)(chong)(chong)電功(gong)能(neng)(neng)和放(fang)電功(gong)能(neng)(neng)，此(ci)時(shi)用(yong)戶(hu)可(ke)以(yi)選擇(ze)自動(dong)模(mo)式和手動(dong)模(mo)式。在(zai)自動(dong)模(mo)式下(xia)，如果用(yong)戶(hu)選擇(ze)并(bing)網(wang)充(chong)(chong)(chong)電或放(fang)電狀態，儲能(neng)(neng)逆變(bian)器將(jiang)以(yi)之(zhi)前設(she)定好(hao)的(de)值對蓄(xu)電池進行充(chong)(chong)(chong)電或放(fang)電。在(zai)手動(dong)模(mo)式下(xia)，用(yong)戶(hu)可(ke)以(yi)通過手動(dong)修改(gai)充(chong)(chong)(chong)電或放(fang)電電流、電壓和時(shi)間值，使儲能(neng)(neng)逆變(bian)器工作在(zai)設(she)定的(de)充(chong)(chong)(chong)電或放(fang)電狀態。

并網模式中，儲能逆變器連接在一個大容量公用電網中，大容量是指該電網的總容量至少比儲能逆變器容量大10倍以上。并網模式的主要特征是儲能逆變器必須與(yu)存在的電(dian)網(wang)頻率(lv)同(tong)步(bu)。要做到與(yu)電(dian)網(wang)同(tong)步(bu)，儲能(neng)逆(ni)變器相(xiang)對于電(dian)網(wang)來說作(zuo)為一(yi)個電(dian)流源。有些情況下，儲能(neng)逆(ni)變器必須能(neng)通過無功控(kong)制為電(dian)網(wang)提供電(dian)壓支持。該模式常用于削峰填(tian)谷、電(dian)力負載平衡和(he)調節電(dian)能(neng)質量。

2、離網模式

孤島系統(tong)(tong)是一(yi)(yi)個(ge)(ge)(ge)或多個(ge)(ge)(ge)發電(dian)(dian)(dian)系統(tong)(tong)并(bing)聯形(xing)成(cheng)一(yi)(yi)個(ge)(ge)(ge)局(ju)部(bu)的(de)(de)“微網(wang)(wang)”。孤島系統(tong)(tong)的(de)(de)主要特征是局(ju)部(bu)電(dian)(dian)(dian)網(wang)(wang)與所有的(de)(de)大電(dian)(dian)(dian)網(wang)(wang)脫離，儲(chu)(chu)能系統(tong)(tong)的(de)(de)額定功(gong)率與局(ju)部(bu)電(dian)(dian)(dian)網(wang)(wang)產(chan)生(sheng)的(de)(de)總功(gong)率大致相等。在(zai)(zai)這個(ge)(ge)(ge)系統(tong)(tong)中，儲(chu)(chu)能系統(tong)(tong)必須(xu)(xu)可以充當網(wang)(wang)路電(dian)(dian)(dian)源，給(gei)局(ju)部(bu)電(dian)(dian)(dian)網(wang)(wang)提供電(dian)(dian)(dian)壓(ya)和(he)頻率控(kong)制。另(ling)一(yi)(yi)方(fang)面，如(ru)果一(yi)(yi)個(ge)(ge)(ge)發電(dian)(dian)(dian)裝(zhuang)置(zhi)不能與其他(ta)發電(dian)(dian)(dian)裝(zhuang)置(zhi)同步，比如(ru)一(yi)(yi)個(ge)(ge)(ge)柴油(you)發電(dian)(dian)(dian)機連接在(zai)(zai)局(ju)部(bu)電(dian)(dian)(dian)網(wang)(wang)上，那么儲(chu)(chu)能系統(tong)(tong)必須(xu)(xu)作為(wei)一(yi)(yi)個(ge)(ge)(ge)電(dian)(dian)(dian)源之(zhi)同步。有些情(qing)況下，儲(chu)(chu)能系統(tong)(tong)還(huan)要在(zai)(zai)作為(wei)電(dian)(dian)(dian)源和(he)與發電(dian)(dian)(dian)裝(zhuang)置(zhi)同步之(zhi)間轉換。

孤島系統的(de)(de)特征是儲能系統與局部電(dian)網(wang)相(xiang)連，這些情形(xing)可(ke)能存(cun)在(zai)于偏遠山區(qu)或小(xiao)島嶼。常見應(ying)用包(bao)括平滑由(you)可(ke)變電(dian)源可(ke)變負載引起的(de)(de)功率波動，穩定電(dian)網(wang)，優化燃料的(de)(de)使用和調(diao)節電(dian)能質量。

3、混合模式

儲能系統(tong)(tong)(tong)能夠在并(bing)網(wang)(wang)模式(shi)和離網(wang)(wang)模式(shi)之間進行切換。儲能系統(tong)(tong)(tong)處于(yu)微網(wang)(wang)中，微網(wang)(wang)與公(gong)共電網(wang)(wang)接，正常工作狀態下(xia)作為并(bing)網(wang)(wang)系統(tong)(tong)(tong)運行如(ru)果(guo)微網(wang)(wang)與公(gong)共電網(wang)(wang)脫(tuo)離，儲能系統(tong)(tong)(tong)將工作在離網(wang)(wang)模式(shi)為微網(wang)(wang)提供(gong)主電源。常見應用包括濾波，穩定電網(wang)(wang)，調節電能質量和創(chuang)造自愈(yu)網(wang)(wang)。