一、儲能變流器是雙向還是單向

儲能變流器（PCS）又(you)稱(cheng)儲能逆變器，是連接儲能電(dian)(dian)池系統(tong)和電(dian)(dian)網(wang)(wang)的雙向電(dian)(dian)流可控轉換裝(zhuang)置，能夠在(zai)電(dian)(dian)網(wang)(wang)和儲能系統(tong)間精確快(kuai)速地調節電(dian)(dian)壓、頻率(lv)、功(gong)率(lv)，實現(xian)恒功(gong)率(lv)恒流充放電(dian)(dian)以及平滑(hua)波(bo)動(dong)性電(dian)(dian)源輸出。

儲能(neng)(neng)變流器不僅能(neng)(neng)滿(man)足傳統并網變流器對(dui)直流電轉(zhuan)換(huan)為交流電的(de)逆變要求(qiu)，還可滿(man)足儲能(neng)(neng)系統“充(chong)電+放電”帶(dai)來(lai)的(de)雙(shuang)向(xiang)變流需求(qiu)，具有對(dui)電池充(chong)電和放電功(gong)能(neng)(neng)，可用于(yu)光伏、風力發電功(gong)率(lv)平滑、削(xue)峰填谷、微型電網等多種場(chang)合。

并網模(mo)式下，在負荷(he)低谷期，儲能變流(liu)(liu)(liu)器把(ba)電(dian)(dian)網的交(jiao)流(liu)(liu)(liu)電(dian)(dian)整流(liu)(liu)(liu)成直流(liu)(liu)(liu)電(dian)(dian)給(gei)電(dian)(dian)池組充電(dian)(dian)，在負荷(he)高峰(feng)期，儲能變流(liu)(liu)(liu)器把(ba)電(dian)(dian)池組中(zhong)的直流(liu)(liu)(liu)電(dian)(dian)逆變成交(jiao)流(liu)(liu)(liu)電(dian)(dian)反送到電(dian)(dian)網中(zhong)。

離網(wang)模式下，儲(chu)能變(bian)流器(qi)與主電(dian)(dian)網(wang)脫開，給本地的部分(fen)負荷提(ti)供(gong)滿足電(dian)(dian)網(wang)電(dian)(dian)能質量要求(qiu)的電(dian)(dian)能。

二、雙向儲能變流器的工作模式有哪些

雙向儲能(neng)變流(liu)器pcs的工作模(mo)式分為并網(wang)模(mo)式、離(li)網(wang)模(mo)式和(he)混(hun)合模(mo)式。

1、并網模式

并網模式(shi)下包括(kuo)充(chong)電(dian)功能(neng)和放電(dian)功能(neng)，此時(shi)用(yong)戶可以(yi)(yi)選擇自動模式(shi)和手動模式(shi)。在(zai)(zai)自動模式(shi)下，如果用(yong)戶選擇并網充(chong)電(dian)或(huo)放電(dian)狀態，儲(chu)能(neng)逆(ni)變器將以(yi)(yi)之前設(she)定好的值(zhi)對蓄電(dian)池進(jin)行充(chong)電(dian)或(huo)放電(dian)。在(zai)(zai)手動模式(shi)下，用(yong)戶可以(yi)(yi)通(tong)過手動修改充(chong)電(dian)或(huo)放電(dian)電(dian)流、電(dian)壓(ya)和時(shi)間值(zhi)，使儲(chu)能(neng)逆(ni)變器工作在(zai)(zai)設(she)定的充(chong)電(dian)或(huo)放電(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存(cun)在的電(dian)(dian)網頻率同步。要做到(dao)與電(dian)(dian)網同步，儲能(neng)逆變器相對于電(dian)(dian)網來(lai)說作為一(yi)個(ge)電(dian)(dian)流源(yuan)。有些情(qing)況(kuang)下，儲能(neng)逆變器必須能(neng)通過無功(gong)控制為電(dian)(dian)網提供電(dian)(dian)壓支(zhi)持。該模式(shi)常(chang)用于削(xue)峰(feng)填谷(gu)、電(dian)(dian)力負載平衡和調(diao)節電(dian)(dian)能(neng)質量。

2、離網模式

孤(gu)島系(xi)(xi)統(tong)(tong)是一(yi)個或(huo)多個發(fa)電(dian)(dian)(dian)系(xi)(xi)統(tong)(tong)并聯(lian)形成一(yi)個局(ju)(ju)部的(de)(de)“微網(wang)”。孤(gu)島系(xi)(xi)統(tong)(tong)的(de)(de)主(zhu)要特征是局(ju)(ju)部電(dian)(dian)(dian)網(wang)與(yu)所有(you)的(de)(de)大電(dian)(dian)(dian)網(wang)脫離，儲(chu)(chu)(chu)能(neng)(neng)系(xi)(xi)統(tong)(tong)的(de)(de)額(e)定功率與(yu)局(ju)(ju)部電(dian)(dian)(dian)網(wang)產生的(de)(de)總功率大致(zhi)相等。在這個系(xi)(xi)統(tong)(tong)中，儲(chu)(chu)(chu)能(neng)(neng)系(xi)(xi)統(tong)(tong)必須可(ke)以充(chong)當網(wang)路電(dian)(dian)(dian)源，給局(ju)(ju)部電(dian)(dian)(dian)網(wang)提(ti)供電(dian)(dian)(dian)壓和(he)頻率控制(zhi)。另(ling)一(yi)方面，如(ru)果一(yi)個發(fa)電(dian)(dian)(dian)裝置不能(neng)(neng)與(yu)其他(ta)發(fa)電(dian)(dian)(dian)裝置同(tong)步(bu)，比如(ru)一(yi)個柴(chai)油發(fa)電(dian)(dian)(dian)機連接(jie)在局(ju)(ju)部電(dian)(dian)(dian)網(wang)上，那么儲(chu)(chu)(chu)能(neng)(neng)系(xi)(xi)統(tong)(tong)必須作為一(yi)個電(dian)(dian)(dian)源之(zhi)同(tong)步(bu)。有(you)些(xie)情況下，儲(chu)(chu)(chu)能(neng)(neng)系(xi)(xi)統(tong)(tong)還要在作為電(dian)(dian)(dian)源和(he)與(yu)發(fa)電(dian)(dian)(dian)裝置同(tong)步(bu)之(zhi)間轉換。

孤島(dao)系統的(de)(de)特征是儲能(neng)系統與局部電(dian)網相連，這些情形可(ke)(ke)能(neng)存在(zai)于偏遠山(shan)區或小(xiao)島(dao)嶼。常見(jian)應(ying)用(yong)包括平(ping)滑(hua)由可(ke)(ke)變電(dian)源可(ke)(ke)變負載引起的(de)(de)功率(lv)波(bo)動，穩(wen)定電(dian)網，優(you)化燃料(liao)的(de)(de)使用(yong)和(he)調節電(dian)能(neng)質量。

3、混合模式

儲(chu)能(neng)系統(tong)(tong)能(neng)夠在并(bing)網(wang)模(mo)式(shi)和(he)離網(wang)模(mo)式(shi)之(zhi)間(jian)進行(xing)(xing)切換。儲(chu)能(neng)系統(tong)(tong)處于微(wei)網(wang)中，微(wei)網(wang)與(yu)公(gong)共(gong)電(dian)網(wang)接，正常工(gong)作狀態下作為(wei)并(bing)網(wang)系統(tong)(tong)運(yun)行(xing)(xing)如果(guo)微(wei)網(wang)與(yu)公(gong)共(gong)電(dian)網(wang)脫(tuo)離，儲(chu)能(neng)系統(tong)(tong)將工(gong)作在離網(wang)模(mo)式(shi)為(wei)微(wei)網(wang)提(ti)供主電(dian)源(yuan)。常見應用包(bao)括濾波，穩定電(dian)網(wang)，調節電(dian)能(neng)質量和(he)創造自愈網(wang)。