一、儲能系統在微電網中的作用
1、提高分布式能源的穩定性
分(fen)布(bu)式(shi)能(neng)(neng)(neng)(neng)源(yuan)(yuan)諸(zhu)如太陽(yang)能(neng)(neng)(neng)(neng)、風能(neng)(neng)(neng)(neng)、生(sheng)物(wu)質能(neng)(neng)(neng)(neng)等可再生(sheng)能(neng)(neng)(neng)(neng)源(yuan)(yuan),普(pu)遍受外界環境如光照(zhao)、溫度、風力、氣候等因(yin)數(shu)影響比較大,所發(fa)電量具備隨機性、不穩定(ding)性特點。在微電網(wang)(wang)與電網(wang)(wang)斷開(kai),獨立運行情況下,微電網(wang)(wang)中分(fen)布(bu)式(shi)能(neng)(neng)(neng)(neng)源(yuan)(yuan)的輸(shu)出(chu)功率(lv)隨著環境因(yin)數(shu)的變(bian)化而變(bian)化,無法為負(fu)荷提供穩定(ding)的輸(shu)出(chu)。儲能(neng)(neng)(neng)(neng)系統應用(yong)于(yu)微電網(wang)(wang)中,通過能(neng)(neng)(neng)(neng)源(yuan)(yuan)管理系統(EMS),將分(fen)布(bu)式(shi)能(neng)(neng)(neng)(neng)源(yuan)(yuan)與儲能(neng)(neng)(neng)(neng)系統、主(zhu)(zhu)電網(wang)(wang)協同控制,可以平穩分(fen)布(bu)式(shi)能(neng)(neng)(neng)(neng)源(yuan)(yuan)的波(bo)動(dong),穩定(ding)輸(shu)出(chu),并(bing)提供分(fen)布(bu)式(shi)能(neng)(neng)(neng)(neng)源(yuan)(yuan)的就地利用(yong)率(lv),避免遠(yuan)距離傳(chuan)輸(shu)給主(zhu)(zhu)電網(wang)(wang)照(zhao)成傳(chuan)輸(shu)壓(ya)力及電力損耗。
除此之外(wai),儲能(neng)系統還能(neng)在夜間(jian),或分(fen)布式能(neng)源維修期間(jian),持續為主(zhu)要負載提(ti)供(gong)部(bu)分(fen)電(dian)源,減(jian)少(shao)停(ting)電(dian)時間(jian)。
2、改善用戶用電的電能質量
在微電(dian)網(wang)(wang)與主電(dian)網(wang)(wang)連接,并網(wang)(wang)運行(xing)時,其電(dian)能(neng)質量必(bi)須符合國家相(xiang)關標(biao)準(zhun),即(ji)功率因數(shu)、電(dian)壓(ya)(ya)不(bu)對稱、電(dian)流諧(xie)波畸(ji)變率、電(dian)壓(ya)(ya)閃(shan)降等(deng)參數(shu)需達到相(xiang)應值。
按以上第一(yi)點(dian)中(zhong)所(suo)述,微(wei)(wei)電(dian)(dian)網在無(wu)儲(chu)能(neng)(neng)系(xi)統的情況下,受其本身(shen)能(neng)(neng)源的特性影(ying)響,無(wu)法(fa)保證電(dian)(dian)能(neng)(neng)質量,尤其是電(dian)(dian)壓穩定(ding)性。儲(chu)能(neng)(neng)系(xi)統的運用,能(neng)(neng)夠對微(wei)(wei)電(dian)(dian)網電(dian)(dian)能(neng)(neng)質量的提(ti)升發揮重要的作用,系(xi)統通過對儲(chu)能(neng)(neng)系(xi)統中(zhong)PCS控制,在穩定(ding)電(dian)(dian)能(neng)(neng)輸出的同(tong)時,調(diao)節儲(chu)能(neng)(neng)系(xi)統向微(wei)(wei)電(dian)(dian)網輸出的有功(gong)、無(wu)功(gong),同(tong)時解(jie)決電(dian)(dian)壓驟(zou)降/跌落問題。
在(zai)面對主電網電壓(ya)驟(zou)升、驟(zou)降等問題時(shi),儲(chu)能系統可以提供快速功(gong)率(lv)緩沖,快速吸收/補充電能,提供有功(gong),無功(gong)功(gong)率(lv)支(zhi)撐,穩定電壓(ya)波動。儲(chu)能系統也能為微電網提供部分諧波治理功(gong)能。
3、調峰
儲(chu)(chu)能(neng)(neng)(neng)(neng)系統在(zai)微(wei)電(dian)網(wang)中(zhong),可(ke)以在(zai)負荷(he)低谷時候,存儲(chu)(chu)分(fen)布式(shi)能(neng)(neng)(neng)(neng)源(yuan)發出的多余(yu)電(dian)能(neng)(neng)(neng)(neng),在(zai)負荷(he)用電(dian)高峰時候釋放電(dian)能(neng)(neng)(neng)(neng),調節負荷(he)需求。儲(chu)(chu)能(neng)(neng)(neng)(neng)系統作為(wei)微(wei)網(wang)中(zhong)能(neng)(neng)(neng)(neng)量緩沖環節,在(zai)微(wei)網(wang)系統中(zhong)是必(bi)不可(ke)少的。
儲能(neng)系統(tong)在滿足峰(feng)值(zhi)負荷用電的同時,可以降低發(fa)電機組或變壓器所需容量(liang)。
二、儲能系統如何運用在微電網
儲(chu)能(neng)(neng)(neng)技術主要(yao)的(de)應用(yong)方向有:①風(feng)力發(fa)電(dian)(dian)(dian)與光伏發(fa)電(dian)(dian)(dian)互補系(xi)統(tong)組成的(de)局域網,用(yong)于(yu)偏遠地區供(gong)電(dian)(dian)(dian)、工廠(chang)及辦公樓供(gong)電(dian)(dian)(dian);②通信系(xi)統(tong)中作為不間斷電(dian)(dian)(dian)源和(he)應急電(dian)(dian)(dian)能(neng)(neng)(neng)系(xi)統(tong);③風(feng)力發(fa)電(dian)(dian)(dian)和(he)光伏發(fa)電(dian)(dian)(dian)系(xi)統(tong)的(de)并網電(dian)(dian)(dian)能(neng)(neng)(neng)質量調(diao)整(zheng);④作為大規(gui)模電(dian)(dian)(dian)力存儲(chu)和(he)負荷調(diao)峰手段;⑤電(dian)(dian)(dian)動汽車儲(chu)能(neng)(neng)(neng)裝置;⑥作為國家(jia)重要(yao)部門的(de)大型(xing)后備電(dian)(dian)(dian)源等。
據業內人士(shi)介紹,微(wei)(wei)電(dian)(dian)(dian)網(wang)是儲能最主要(yao)的應(ying)用領域,作為微(wei)(wei)電(dian)(dian)(dian)網(wang)中(zhong)必不可少(shao)的部分,儲能在微(wei)(wei)電(dian)(dian)(dian)網(wang)中(zhong)發揮了至關重要(yao)的作用。
通常來說(shuo),微(wei)電(dian)(dian)網的一般結構由能(neng)(neng)(neng)源(yuan)流和信息(xi)流相互(hu)融(rong)合而成(cheng),分為分布式能(neng)(neng)(neng)源(yuan)、儲能(neng)(neng)(neng)裝置、電(dian)(dian)能(neng)(neng)(neng)變換裝置、保(bao)護裝置和微(wei)電(dian)(dian)網能(neng)(neng)(neng)源(yuan)管理系統(tong)組(zu)成(cheng),也可根據實際應用情(qing)況進行(xing)增減。相對于大電(dian)(dian)網,微(wei)電(dian)(dian)網表現為單一的受控單元(yuan),它可以(yi)保(bao)證用戶電(dian)(dian)能(neng)(neng)(neng)的質量(liang)和供電(dian)(dian)安全,同時(shi)也是智(zhi)能(neng)(neng)(neng)電(dian)(dian)網及能(neng)(neng)(neng)源(yuan)互(hu)聯(lian)網的重(zhong)要(yao)組(zu)成(cheng)部分。
在(zai)(zai)微電(dian)(dian)網(wang)(wang)(wang)(wang)(wang)運(yun)(yun)行(xing)中,有(you)兩種運(yun)(yun)行(xing)模(mo)(mo)式(shi)(shi):并網(wang)(wang)(wang)(wang)(wang)運(yun)(yun)行(xing)模(mo)(mo)式(shi)(shi)和孤島運(yun)(yun)行(xing)模(mo)(mo)式(shi)(shi)。并網(wang)(wang)(wang)(wang)(wang)運(yun)(yun)行(xing)模(mo)(mo)式(shi)(shi)是(shi)在(zai)(zai)外(wai)部無故障(zhang)時(shi)(shi),微電(dian)(dian)網(wang)(wang)(wang)(wang)(wang)與外(wai)部電(dian)(dian)網(wang)(wang)(wang)(wang)(wang)處于連接的(de)(de)狀態(tai);孤島運(yun)(yun)行(xing)模(mo)(mo)式(shi)(shi)是(shi)當外(wai)部電(dian)(dian)網(wang)(wang)(wang)(wang)(wang)發生(sheng)故障(zhang)或者電(dian)(dian)能質量較差時(shi)(shi),微電(dian)(dian)網(wang)(wang)(wang)(wang)(wang)通過(guo)快速(su)開關可以切斷與外(wai)電(dian)(dian)網(wang)(wang)(wang)(wang)(wang)的(de)(de)連接,進入獨立運(yun)(yun)行(xing)的(de)(de)狀態(tai),保(bao)證微電(dian)(dian)網(wang)(wang)(wang)(wang)(wang)內部重要(yao)負(fu)荷(he)的(de)(de)供電(dian)(dian)可靠性(xing)。在(zai)(zai)微電(dian)(dian)網(wang)(wang)(wang)(wang)(wang)孤島運(yun)(yun)行(xing)模(mo)(mo)式(shi)(shi)時(shi)(shi),能量來(lai)源于分(fen)布式(shi)(shi)能源和儲(chu)能電(dian)(dian)池,當分(fen)布式(shi)(shi)能源的(de)(de)出(chu)力小于負(fu)荷(he)需求時(shi)(shi),就會存在(zai)(zai)一定的(de)(de)功率缺額,解決功率缺額的(de)(de)方法(fa)就是(shi)在(zai)(zai)微網(wang)(wang)(wang)(wang)(wang)系統(tong)中配備(bei)一定容量的(de)(de)儲(chu)能設備(bei)。
在新能源發電中(zhong),經常會由于(yu)外(wai)界環境條(tiao)件的(de)(de)變(bian)化而(er)出現沒(mei)有電能輸出的(de)(de)情(qing)況(kuang),例(li)如(ru)光伏發電遇到的(de)(de)夜間無光源的(de)(de)情(qing)況(kuang)和(he)風力發電中(zhong)的(de)(de)沒(mei)有風吹過(guo)的(de)(de)情(qing)況(kuang)等(deng),這個時候(hou)就需要(yao)儲(chu)能系統向(xiang)微電網系統中(zhong)的(de)(de)用戶(hu)提供持續的(de)(de)供電。
小(xiao)編查閱資料發(fa)現,儲能技(ji)術進步最(zui)快的(de)就是(shi)電(dian)(dian)(dian)化學儲能技(ji)術,以鋰離子電(dian)(dian)(dian)池、鉛(qian)炭電(dian)(dian)(dian)池、液流電(dian)(dian)(dian)池為主(zhu)導的(de)電(dian)(dian)(dian)化學儲能技(ji)術在安全性、能量轉換效率和經濟性等方面均取得了重大(da)突破,極具產業化應用前景。
隨著全球可再生能源的普及和電動汽車產業的迅速發展,動力電池也將迎來巨大的市場,此后也將出現大量動力電池退役的回收再利用問題。在業內人士(shi)看來(lai)(lai),退役后性能(neng)尚可的(de)動力(li)電池可作為儲能(neng)電池繼續服役,這(zhe)個應(ying)用隨著我國電動汽(qi)車的(de)發展將帶來(lai)(lai)儲能(neng)發展的(de)良機,這(zhe)將會(hui)一(yi)個是非(fei)常好(hao)的(de)應(ying)用領域。
電(dian)力(li)安(an)全(quan)是(shi)(shi)國(guo)家(jia)能源(yuan)安(an)全(quan)的重要組成,儲能是(shi)(shi)保證電(dian)力(li)安(an)全(quan)、低碳(tan)、高效供(gong)給的重要技(ji)術(shu),是(shi)(shi)支撐新能源(yuan)電(dian)力(li)大規模發展的重要技(ji)術(shu),也是(shi)(shi)未來智能電(dian)網框(kuang)架內的關(guan)鍵支撐技(ji)術(shu)。
能(neng)(neng)源(yuan)(yuan)互(hu)聯網作為未來(lai)全球能(neng)(neng)源(yuan)(yuan)的(de)發展(zhan)方向,需要從(cong)根本上改變現在的(de)發、輸(shu)、變、配(pei)、用的(de)環節配(pei)置,這就決定了未來(lai)電力(li)的(de)潮流控(kong)制、分布式電源(yuan)(yuan)及微網將廣泛應用,儲能(neng)(neng)技術將是協(xie)調這些應用的(de)至關重要的(de)一環。
目前(qian),我(wo)國儲(chu)(chu)(chu)能(neng)(neng)(neng)(neng)技(ji)術(shu)發(fa)展落后于應用需求,業(ye)內人士(shi)認為,如果未(wei)來(lai)國家能(neng)(neng)(neng)(neng)夠(gou)從宏觀戰略層(ceng)面上制定儲(chu)(chu)(chu)能(neng)(neng)(neng)(neng)發(fa)展規(gui)劃(hua),加強對儲(chu)(chu)(chu)能(neng)(neng)(neng)(neng)技(ji)術(shu)研發(fa)與示范的資(zi)(zi)金支持(chi)力度,出臺利于儲(chu)(chu)(chu)能(neng)(neng)(neng)(neng)技(ji)術(shu)產業(ye)化的激勵政(zheng)策與機(ji)制,引導社會資(zi)(zi)金向儲(chu)(chu)(chu)能(neng)(neng)(neng)(neng)產業(ye)傾斜,使得儲(chu)(chu)(chu)能(neng)(neng)(neng)(neng)項目投(tou)資(zi)(zi)能(neng)(neng)(neng)(neng)夠(gou)獲得回報,相信在未(wei)來(lai),微(wei)電網及儲(chu)(chu)(chu)能(neng)(neng)(neng)(neng)應用將會迎來(lai)大規(gui)模的快速發(fa)展時期。