一、儲能變流器是雙向還是單向

儲能變流器（PCS）又(you)稱儲能(neng)(neng)逆變(bian)器，是連接儲能(neng)(neng)電(dian)(dian)池系(xi)統和(he)電(dian)(dian)網的雙向電(dian)(dian)流可控(kong)轉換裝置(zhi)，能(neng)(neng)夠在電(dian)(dian)網和(he)儲能(neng)(neng)系(xi)統間精確(que)快速(su)地(di)調節電(dian)(dian)壓(ya)、頻率(lv)、功(gong)率(lv)，實現恒功(gong)率(lv)恒流充放電(dian)(dian)以及(ji)平滑(hua)波動(dong)性電(dian)(dian)源輸出。

儲(chu)能(neng)變流器不僅(jin)能(neng)滿(man)足傳統并(bing)網變流器對直流電(dian)(dian)(dian)轉(zhuan)換(huan)為交流電(dian)(dian)(dian)的逆變要求，還(huan)可(ke)滿(man)足儲(chu)能(neng)系(xi)統“充電(dian)(dian)(dian)+放電(dian)(dian)(dian)”帶來的雙向(xiang)變流需求，具有對電(dian)(dian)(dian)池充電(dian)(dian)(dian)和放電(dian)(dian)(dian)功能(neng)，可(ke)用于光伏(fu)、風力發電(dian)(dian)(dian)功率(lv)平滑、削峰填谷、微型電(dian)(dian)(dian)網等多種場合。

并網模式下，在負荷(he)低谷期，儲(chu)能(neng)變(bian)(bian)流器把電(dian)網的交流電(dian)整(zheng)流成(cheng)直流電(dian)給電(dian)池組(zu)充電(dian)，在負荷(he)高峰(feng)期，儲(chu)能(neng)變(bian)(bian)流器把電(dian)池組(zu)中(zhong)的直流電(dian)逆變(bian)(bian)成(cheng)交流電(dian)反送到電(dian)網中(zhong)。

離網(wang)模式下，儲能(neng)變流器(qi)與主電網(wang)脫開，給本地的部分負(fu)荷(he)提(ti)供滿足電網(wang)電能(neng)質量要求的電能(neng)。

二、雙向儲能變流器的工作模式有哪些

雙向(xiang)儲能變流器pcs的工作模式分(fen)為(wei)并網模式、離網模式和混(hun)合模式。

1、并網模式

并(bing)(bing)網(wang)模(mo)(mo)(mo)式(shi)(shi)下包括充電(dian)(dian)功(gong)能(neng)(neng)和(he)(he)放(fang)電(dian)(dian)功(gong)能(neng)(neng)，此時(shi)用(yong)(yong)(yong)戶可以(yi)選擇自動(dong)模(mo)(mo)(mo)式(shi)(shi)和(he)(he)手(shou)動(dong)模(mo)(mo)(mo)式(shi)(shi)。在(zai)自動(dong)模(mo)(mo)(mo)式(shi)(shi)下，如果用(yong)(yong)(yong)戶選擇并(bing)(bing)網(wang)充電(dian)(dian)或放(fang)電(dian)(dian)狀態，儲能(neng)(neng)逆(ni)變(bian)器將(jiang)以(yi)之前設定(ding)好的值(zhi)對(dui)蓄(xu)電(dian)(dian)池進行充電(dian)(dian)或放(fang)電(dian)(dian)。在(zai)手(shou)動(dong)模(mo)(mo)(mo)式(shi)(shi)下，用(yong)(yong)(yong)戶可以(yi)通過手(shou)動(dong)修改(gai)充電(dian)(dian)或放(fang)電(dian)(dian)電(dian)(dian)流、電(dian)(dian)壓和(he)(he)時(shi)間值(zhi)，使儲能(neng)(neng)逆(ni)變(bian)器工作在(zai)設定(ding)的充電(dian)(dian)或放(fang)電(dian)(dian)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(zai)的電(dian)(dian)網頻率同步。要做到(dao)與(yu)電(dian)(dian)網同步，儲能逆變(bian)器(qi)相對于電(dian)(dian)網來說作為(wei)一個電(dian)(dian)流源(yuan)。有些情況下(xia)，儲能逆變(bian)器(qi)必須能通過無功控(kong)制為(wei)電(dian)(dian)網提(ti)供電(dian)(dian)壓(ya)支持。該模(mo)式常用于削(xue)峰填谷、電(dian)(dian)力負載平衡和調節電(dian)(dian)能質量(liang)。

2、離網模式

孤(gu)島(dao)系(xi)(xi)(xi)統是一(yi)個或(huo)多(duo)個發(fa)電(dian)系(xi)(xi)(xi)統并聯形成一(yi)個局(ju)部的“微網(wang)”。孤(gu)島(dao)系(xi)(xi)(xi)統的主要(yao)特征(zheng)是局(ju)部電(dian)網(wang)與所(suo)有(you)的大電(dian)網(wang)脫離，儲能(neng)系(xi)(xi)(xi)統的額定(ding)功率(lv)(lv)與局(ju)部電(dian)網(wang)產生的總功率(lv)(lv)大致相等。在這(zhe)個系(xi)(xi)(xi)統中，儲能(neng)系(xi)(xi)(xi)統必須(xu)可以充當網(wang)路電(dian)源(yuan)(yuan)，給局(ju)部電(dian)網(wang)提供電(dian)壓和頻(pin)率(lv)(lv)控制。另(ling)一(yi)方面(mian)，如(ru)果一(yi)個發(fa)電(dian)裝(zhuang)置(zhi)不能(neng)與其他(ta)發(fa)電(dian)裝(zhuang)置(zhi)同(tong)步，比如(ru)一(yi)個柴油發(fa)電(dian)機(ji)連接在局(ju)部電(dian)網(wang)上，那么儲能(neng)系(xi)(xi)(xi)統必須(xu)作為一(yi)個電(dian)源(yuan)(yuan)之同(tong)步。有(you)些情況(kuang)下(xia)，儲能(neng)系(xi)(xi)(xi)統還要(yao)在作為電(dian)源(yuan)(yuan)和與發(fa)電(dian)裝(zhuang)置(zhi)同(tong)步之間(jian)轉換。

孤島(dao)系統的特征(zheng)是儲能(neng)系統與(yu)局部電(dian)(dian)網相連，這些情形(xing)可(ke)(ke)能(neng)存在于偏遠(yuan)山區(qu)或小島(dao)嶼。常見應用包括平滑(hua)由可(ke)(ke)變電(dian)(dian)源(yuan)可(ke)(ke)變負載(zai)引(yin)起的功率波動(dong)，穩(wen)定(ding)電(dian)(dian)網，優(you)化燃料的使用和(he)調(diao)節(jie)電(dian)(dian)能(neng)質量(liang)。

3、混合模式

儲能系(xi)統(tong)能夠(gou)在(zai)并網(wang)(wang)(wang)(wang)模式(shi)和(he)(he)離(li)網(wang)(wang)(wang)(wang)模式(shi)之間進行切(qie)換(huan)。儲能系(xi)統(tong)處于微(wei)網(wang)(wang)(wang)(wang)中(zhong)，微(wei)網(wang)(wang)(wang)(wang)與(yu)(yu)公共電網(wang)(wang)(wang)(wang)接，正常(chang)工(gong)作狀(zhuang)態下作為(wei)并網(wang)(wang)(wang)(wang)系(xi)統(tong)運行如(ru)果微(wei)網(wang)(wang)(wang)(wang)與(yu)(yu)公共電網(wang)(wang)(wang)(wang)脫離(li)，儲能系(xi)統(tong)將(jiang)工(gong)作在(zai)離(li)網(wang)(wang)(wang)(wang)模式(shi)為(wei)微(wei)網(wang)(wang)(wang)(wang)提供主電源。常(chang)見應用(yong)包括濾波，穩定電網(wang)(wang)(wang)(wang)，調節電能質量和(he)(he)創造自愈網(wang)(wang)(wang)(wang)。