摘(zhai)要：
隨著風電并網容(rong)量不(bu)斷增大，風電隨機性(xing)和間歇性(xing)特(te)點造成(cheng)的(de)(de)電壓不(bu)穩定問題也日益嚴重(zhong)。為了使穩態電壓保持在規定的(de)(de)范圍內，需要在風電場選擇合適的(de)(de)無功補償(chang)裝置。
前言
根據(ju)風(feng)電(dian)(dian)(dian)場接(jie)入(ru)(ru)電(dian)(dian)(dian)力(li)系統技術規(gui)定，對直接(jie)接(jie)入(ru)(ru)公共(gong)電(dian)(dian)(dian)網的(de)風(feng)電(dian)(dian)(dian)場，其配(pei)置(zhi)(zhi)的(de)容性(xing)(xing)(xing)無功(gong)容量能(neng)(neng)夠(gou)補償風(feng)電(dian)(dian)(dian)場滿發(fa)時(shi)場內匯集線路，主變壓(ya)器的(de)感性(xing)(xing)(xing)無功(gong)及(ji)風(feng)電(dian)(dian)(dian)場送出線路的(de)一半感性(xing)(xing)(xing)無功(gong)之和，配(pei)置(zhi)(zhi)的(de)感性(xing)(xing)(xing)無功(gong)容量能(neng)(neng)夠(gou)補償風(feng)電(dian)(dian)(dian)場自身的(de)容性(xing)(xing)(xing)充電(dian)(dian)(dian)無功(gong)功(gong)率(lv)即風(feng)電(dian)(dian)(dian)場送出線路的(de)一半容性(xing)(xing)(xing)無功(gong)之和。國網還規(gui)定了動態(tai)無功(gong)補償的(de)時(shi)間不(bu)大于30ms。
在(zai)滿足規定的(de)條(tiao)件下，現(xian)在(zai)常用的(de)補(bu)償(chang)方式有三種(zhong)：
1、集中并(bing)聯電(dian)容(rong)(rong)器(qi)組(zu)。只(zhi)能產(chan)生(sheng)容(rong)(rong)性無功，需要根據運行情況(kuang)通過投切電(dian)容(rong)(rong)器(qi)組(zu)來調整補(bu)償容(rong)(rong)量(liang)。一(yi)般有電(dian)容(rong)(rong)器(qi)，串聯電(dian)抗(kang)器(qi)，避(bi)雷器(qi)，斷路器(qi)，放(fang)電(dian)線(xian)圈及(ji)相應的控制(zhi)儀表保護(hu)裝置(zhi)組(zu)成，簡稱(cheng)FC;
2、靜止無功(gong)補償裝置，即SVC。可實現平滑動態補償，按(an)照電網(wang)的無功(gong)需求動態產生容性無功(gong)和 感性無功(gong);
3、靜止無功(gong)發生(sheng)器(qi)，即SVG。SVG相當于一(yi)個(ge)可以產(chan)生(sheng)超(chao)(chao)前或滯后90度(du)電(dian)(dian)(dian)(dian)流的(de)逆(ni)變器(qi)，同時帶有自整流充電(dian)(dian)(dian)(dian)能力(li)。SVG是從電(dian)(dian)(dian)(dian)網取得電(dian)(dian)(dian)(dian)壓向一(yi)個(ge)直流電(dian)(dian)(dian)(dian)容(rong)充電(dian)(dian)(dian)(dian)，再將直流電(dian)(dian)(dian)(dian)壓逆(ni)變成交流電(dian)(dian)(dian)(dian)壓送回電(dian)(dian)(dian)(dian)網。通過產(chan)生(sheng)超(chao)(chao)前或滯后電(dian)(dian)(dian)(dian)流得到感性或容(rong)性的(de)無功(gong)輸出(chu)。
FC的價(jia)格便宜，被廣泛應(ying)用在風場(chang)中(zhong)。在FC不能達到要求(qiu)的情(qing)況下，需(xu)要用可動態調整的SVC和(he)SVG。由于(yu)SVC故障率高，且動態響應(ying)時間長，目前(qian)一般采用SVG作為動態無功補償裝置。根據經濟(ji)性計算，也可采用FC+SVG的方式來降低(di)投資(zi)成本。此類場(chang)合，督(du)凱(kai)提、諾基亞、希(xi)拓電(dian)氣(qi)等品牌(pai)市場(chang)占有率非(fei)常可觀(guan)。
STTELEC轉(zhuan)自《中國(guo)節能網》
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