一、儲能變流器是雙向還是單向
儲能變流器(PCS)又稱儲(chu)能逆變器,是連接儲(chu)能電池系統和(he)電網的雙向電流(liu)可控轉換裝置,能夠(gou)在電網和(he)儲(chu)能系統間精確快速地調節電壓、頻率(lv)(lv)、功率(lv)(lv),實現(xian)恒功率(lv)(lv)恒流(liu)充放電以及平滑波動性電源輸出。
儲能(neng)變流(liu)器不僅能(neng)滿足傳統并網變流(liu)器對直流(liu)電(dian)(dian)(dian)轉(zhuan)換為交流(liu)電(dian)(dian)(dian)的逆變要(yao)求(qiu),還可滿足儲能(neng)系統“充電(dian)(dian)(dian)+放電(dian)(dian)(dian)”帶(dai)來的雙向變流(liu)需(xu)求(qiu),具有對電(dian)(dian)(dian)池充電(dian)(dian)(dian)和放電(dian)(dian)(dian)功能(neng),可用(yong)于(yu)光(guang)伏、風力發電(dian)(dian)(dian)功率(lv)平滑、削峰填谷、微型(xing)電(dian)(dian)(dian)網等(deng)多種(zhong)場合(he)。
并(bing)網(wang)模式下(xia),在負荷低谷期,儲能變(bian)流(liu)器把電(dian)網(wang)的交流(liu)電(dian)整(zheng)流(liu)成直(zhi)流(liu)電(dian)給(gei)電(dian)池組充電(dian),在負荷高峰期,儲能變(bian)流(liu)器把電(dian)池組中(zhong)的直(zhi)流(liu)電(dian)逆變(bian)成交流(liu)電(dian)反送到電(dian)網(wang)中(zhong)。
離網(wang)模式下,儲能變流器與主電(dian)網(wang)脫開,給本(ben)地的部(bu)分負(fu)荷提(ti)供(gong)滿足電(dian)網(wang)電(dian)能質量要求的電(dian)能。
二、雙向儲能變流器的工作模式有哪些
雙(shuang)向儲能變流器pcs的工作(zuo)模(mo)式分為并網模(mo)式、離(li)網模(mo)式和(he)混合模(mo)式。
1、并網模式
并網模(mo)式(shi)下包括充電(dian)功能(neng)和(he)放電(dian)功能(neng),此時用(yong)戶可以(yi)選擇自(zi)動模(mo)式(shi)和(he)手(shou)動模(mo)式(shi)。在(zai)自(zi)動模(mo)式(shi)下,如果用(yong)戶選擇并網充電(dian)或(huo)放電(dian)狀態(tai),儲能(neng)逆(ni)(ni)變(bian)器將以(yi)之前設(she)定好的值(zhi)對蓄電(dian)池進行充電(dian)或(huo)放電(dian)。在(zai)手(shou)動模(mo)式(shi)下,用(yong)戶可以(yi)通過(guo)手(shou)動修改充電(dian)或(huo)放電(dian)電(dian)流、電(dian)壓和(he)時間值(zhi),使(shi)儲能(neng)逆(ni)(ni)變(bian)器工(gong)作(zuo)在(zai)設(she)定的充電(dian)或(huo)放電(dian)狀態(tai)。
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在的電(dian)網(wang)(wang)頻率(lv)同(tong)步(bu)。要(yao)做到與電(dian)網(wang)(wang)同(tong)步(bu),儲能(neng)逆變(bian)器相對于(yu)電(dian)網(wang)(wang)來說(shuo)作為一個電(dian)流源。有些情況下,儲能(neng)逆變(bian)器必須能(neng)通過無功控制(zhi)為電(dian)網(wang)(wang)提(ti)供電(dian)壓支持。該模式(shi)常(chang)用于(yu)削峰填谷(gu)、電(dian)力負載平衡和調節電(dian)能(neng)質量(liang)。
2、離網模式
孤(gu)島(dao)系(xi)統是一個或(huo)多(duo)個發(fa)(fa)電(dian)(dian)(dian)系(xi)統并聯形成一個局部(bu)的“微網(wang)(wang)(wang)”。孤(gu)島(dao)系(xi)統的主要特(te)征是局部(bu)電(dian)(dian)(dian)網(wang)(wang)(wang)與所(suo)有(you)的大電(dian)(dian)(dian)網(wang)(wang)(wang)脫離(li),儲能系(xi)統的額定功(gong)率(lv)與局部(bu)電(dian)(dian)(dian)網(wang)(wang)(wang)產生的總功(gong)率(lv)大致相等(deng)。在這個系(xi)統中,儲能系(xi)統必(bi)須可以充當網(wang)(wang)(wang)路(lu)電(dian)(dian)(dian)源,給局部(bu)電(dian)(dian)(dian)網(wang)(wang)(wang)提供(gong)電(dian)(dian)(dian)壓和頻率(lv)控(kong)制。另一方面,如(ru)果一個發(fa)(fa)電(dian)(dian)(dian)裝置(zhi)不能與其他發(fa)(fa)電(dian)(dian)(dian)裝置(zhi)同(tong)步(bu),比如(ru)一個柴油發(fa)(fa)電(dian)(dian)(dian)機連接在局部(bu)電(dian)(dian)(dian)網(wang)(wang)(wang)上,那(nei)么儲能系(xi)統必(bi)須作為一個電(dian)(dian)(dian)源之(zhi)同(tong)步(bu)。有(you)些情況下,儲能系(xi)統還要在作為電(dian)(dian)(dian)源和與發(fa)(fa)電(dian)(dian)(dian)裝置(zhi)同(tong)步(bu)之(zhi)間轉換。
孤島系統的(de)特(te)征是儲能系統與局部電網(wang)相連,這些(xie)情形可(ke)能存在于偏遠(yuan)山區(qu)或小島嶼。常見應用包括(kuo)平滑由可(ke)變電源可(ke)變負(fu)載(zai)引起的(de)功率波動,穩定電網(wang),優(you)化燃料(liao)的(de)使用和調節電能質(zhi)量。
3、混合模式
儲(chu)能系(xi)統(tong)能夠在并網(wang)(wang)(wang)(wang)模(mo)式和離(li)網(wang)(wang)(wang)(wang)模(mo)式之間進(jin)行(xing)切換(huan)。儲(chu)能系(xi)統(tong)處于微(wei)網(wang)(wang)(wang)(wang)中,微(wei)網(wang)(wang)(wang)(wang)與公共(gong)電(dian)(dian)網(wang)(wang)(wang)(wang)接,正常(chang)工(gong)作(zuo)(zuo)狀態(tai)下作(zuo)(zuo)為并網(wang)(wang)(wang)(wang)系(xi)統(tong)運行(xing)如果微(wei)網(wang)(wang)(wang)(wang)與公共(gong)電(dian)(dian)網(wang)(wang)(wang)(wang)脫離(li),儲(chu)能系(xi)統(tong)將(jiang)工(gong)作(zuo)(zuo)在離(li)網(wang)(wang)(wang)(wang)模(mo)式為微(wei)網(wang)(wang)(wang)(wang)提供主電(dian)(dian)源(yuan)。常(chang)見(jian)應用包括(kuo)濾波(bo),穩定電(dian)(dian)網(wang)(wang)(wang)(wang),調節電(dian)(dian)能質量(liang)和創造自愈網(wang)(wang)(wang)(wang)。