近年來，隨著經濟飛速發展，電能質量管理的概念在各大企業中得到了廣泛的關注，“用電安全、用電質量、用電經濟”理念深入人心，無功功率補償作為電能質量管理的重要組成部分，也成為了廣大電力人研究的方向。國家對于無功功率不達標的企業更加是使用了鐵腕政策，力率電費也成為了一些用電企業的負擔。對于此種情況，安徽得潤電氣(qi)作為專業生產無功(gong)(gong)(gong)補償(chang)裝置(zhi)的廠家，對低(di)壓(ya)無功(gong)(gong)(gong)功(gong)(gong)(gong)率補償(chang)裝置(zhi)的設計與選型進行了闡述與分析，并舉例(li)說明了低(di)壓(ya)無功(gong)(gong)(gong)功(gong)(gong)(gong)率裝置(zhi)在現場的運行與應用。

1 有(you)功(gong)(gong)功(gong)(gong)率(lv)和無功(gong)(gong)功(gong)(gong)率(lv)

在(zai)交流(liu)電(dian)路(lu)中(zhong)，由電(dian)源供給負載的(de)電(dian)功(gong)(gong)率(lv)有(you)兩種；一種是有(you)功(gong)(gong)功(gong)(gong)率(lv)，一種是無功(gong)(gong)功(gong)(gong)率(lv)。

有功(gong)(gong)(gong)功(gong)(gong)(gong)率(lv)(lv)是保持(chi)用電(dian)設(she)備正常運(yun)行所需的(de)電(dian)功(gong)(gong)(gong)率(lv)(lv)，也就是將電(dian)能轉(zhuan)換為其(qi)他形式(shi)能量(liang)（機械能、光能、熱能）的(de)電(dian)功(gong)(gong)(gong)率(lv)(lv)。

無功功率比較抽象(xiang)，它用于電(dian)路內電(dian)場與磁(ci)場的交換，并用來在電(dian)氣設備中(zhong)建立和維(wei)持(chi)磁(ci)場的電(dian)功率。

視在功率(lv)(lv)(lv)、有功功率(lv)(lv)(lv)、無功功率(lv)(lv)(lv)的關系可以(yi)從功率(lv)(lv)(lv)三角(jiao)形(xing)上得(de)出，公式(shi)如(ru)下所示：

舉個實(shi)例來(lai)說，電(dian)動(dong)機需要建立和維持(chi)旋轉磁場(chang)，使轉子轉動(dong)，從(cong)而帶動(dong)機械運動(dong)，電(dian)動(dong)機的轉子磁場(chang)就是(shi)靠從(cong)電(dian)源取得無功(gong)功(gong)率(lv)建立的。變(bian)壓器(qi)也同樣需要無功(gong)功(gong)率(lv)，才能使變(bian)壓器(qi)的一次線圈產(chan)生(sheng)磁場(chang)，在二(er)次線圈感應出電(dian)壓。

因此，無(wu)功(gong)功(gong)率(lv)不(bu)(bu)是(shi)無(wu)用功(gong)率(lv)，它(ta)在電(dian)力系統(tong)中占據了一個重要的位置(zhi)。沒有無(wu)功(gong)功(gong)率(lv)，電(dian)動機就不(bu)(bu)會轉動，變壓(ya)器也不(bu)(bu)能(neng)變壓(ya)，交流接觸器不(bu)(bu)會吸合。

2 低壓無功(gong)功(gong)率補償裝置簡介

低壓無(wu)功(gong)(gong)功(gong)(gong)率(lv)(lv)補(bu)償(chang)(chang)裝置(zhi)(zhi)(zhi)，在(zai)電(dian)(dian)(dian)(dian)力(li)供(gong)電(dian)(dian)(dian)(dian)系統(tong)(tong)中(zhong)所(suo)承擔的(de)(de)作用(yong)是提高電(dian)(dian)(dian)(dian)網(wang)的(de)(de)功(gong)(gong)率(lv)(lv)因(yin)數，降(jiang)低供(gong)電(dian)(dian)(dian)(dian)變壓器及輸(shu)送線路的(de)(de)損耗(hao)，提高供(gong)電(dian)(dian)(dian)(dian)效率(lv)(lv)，改(gai)善供(gong)電(dian)(dian)(dian)(dian)環境。所(suo)以無(wu)功(gong)(gong)功(gong)(gong)率(lv)(lv)補(bu)償(chang)(chang)裝置(zhi)(zhi)(zhi)在(zai)電(dian)(dian)(dian)(dian)力(li)供(gong)電(dian)(dian)(dian)(dian)系統(tong)(tong)中(zhong)處(chu)在(zai)一(yi)個不(bu)(bu)可缺少(shao)的(de)(de)位置(zhi)(zhi)(zhi)。合(he)理的(de)(de)選擇低壓無(wu)功(gong)(gong)功(gong)(gong)率(lv)(lv)補(bu)償(chang)(chang)裝置(zhi)(zhi)(zhi)，可以最大限(xian)度的(de)(de)減少(shao)網(wang)絡的(de)(de)損耗(hao)，使用(yong)戶用(yong)電(dian)(dian)(dian)(dian)質量提高。反之，不(bu)(bu)合(he)理地選擇或者使用(yong)方法不(bu)(bu)當，也有可能會(hui)造成供(gong)電(dian)(dian)(dian)(dian)系統(tong)(tong)電(dian)(dian)(dian)(dian)壓波(bo)動、閃變、諧(xie)波(bo)放大等多種不(bu)(bu)可控的(de)(de)因(yin)素(su)。

3 無功補(bu)償裝置的原理

從(cong)功(gong)(gong)(gong)率三角形可以看出(chu)(chu)，用戶的變壓器容量（S）是固定的，如果用戶的設(she)(she)備需要(yao)的無功(gong)(gong)(gong)功(gong)(gong)(gong)率（Q）過大(da)，就(jiu)會使(shi)有功(gong)(gong)(gong)功(gong)(gong)(gong)率（P）的出(chu)(chu)力(li)減(jian)少(shao)。這(zhe)不僅會使(shi)得(de)使(shi)用電設(she)(she)備不能(neng)(neng)正常工作，還可能(neng)(neng)造成線路過載(zai)導(dao)致設(she)(she)備損壞，此時，就(jiu)需要(yao)對電力(li)系(xi)統進行(xing)無功(gong)(gong)(gong)功(gong)(gong)(gong)率補償。

如圖1所(suo)示(shi)，在進行無功功率(lv)(lv)補(bu)償前(qian)，負載的無功功率(lv)(lv)、有功功率(lv)(lv)均(jun)通過變壓器(qi)來自(zi)于電(dian)網，就會導致電(dian)網的功率(lv)(lv)因數降低，電(dian)能質量下降，用電(dian)效率(lv)(lv)差。

圖2對設(she)備(bei)進行了無(wu)功(gong)(gong)功(gong)(gong)率(lv)(lv)(lv)的(de)補償，此時(shi)設(she)備(bei)的(de)有(you)功(gong)(gong)功(gong)(gong)率(lv)(lv)(lv)通過變壓器來自于電網，而無(wu)功(gong)(gong)功(gong)(gong)率(lv)(lv)(lv)取自我(wo)們的(de)無(wu)功(gong)(gong)補償設(she)備(bei)。假設(she)設(she)備(bei)的(de)無(wu)功(gong)(gong)功(gong)(gong)率(lv)(lv)(lv)均(jun)從無(wu)功(gong)(gong)補償設(she)備(bei)提取，此時(shi)，從電網側來看，無(wu)功(gong)(gong)功(gong)(gong)率(lv)(lv)(lv)（Q）為(wei)0，此時(shi)的(de)視在(zai)功(gong)(gong)率(lv)(lv)(lv)（S）等于有(you)功(gong)(gong)功(gong)(gong)率(lv)(lv)(lv)（P），功(gong)(gong)率(lv)(lv)(lv)因(yin)數(shu)為(wei)1。此時(shi)電網的(de)供(gong)電效率(lv)(lv)(lv)是(shi)最高的(de)，此種情況雖然為(wei)理(li)想狀態，但在(zai)實(shi)際運營過程中(zhong)，只(zhi)要補償得當，月平均(jun)功(gong)(gong)率(lv)(lv)(lv)因(yin)數(shu)達到0.95以上是(shi)沒(mei)有(you)問題的(de)

圖1無功(gong)補償前圖例(li)  

圖2無功補償(chang)后(hou)圖例(li)

4 無功補償的重(zhong)要性

一(yi)(yi)(yi)般來說，使(shi)用無功(gong)(gong)(gong)補(bu)償裝置(zhi)來提(ti)(ti)高(gao)功(gong)(gong)(gong)率(lv)因(yin)數(shu)的意義體(ti)現在(zai)兩個方面：一(yi)(yi)(yi)是可以減少輸電(dian)(dian)(dian)線路(lu)上(shang)的功(gong)(gong)(gong)率(lv)損失；二是可以充分發揮電(dian)(dian)(dian)力設備(bei)(bei)(bei)（如電(dian)(dian)(dian)機(ji)、變(bian)壓(ya)(ya)器(qi)等）的潛(qian)力。因(yin)為(wei)用電(dian)(dian)(dian)電(dian)(dian)(dian)器(qi)總是在(zai)一(yi)(yi)(yi)定(ding)(ding)(ding)(ding)(ding)電(dian)(dian)(dian)壓(ya)(ya)和(he)一(yi)(yi)(yi)定(ding)(ding)(ding)(ding)(ding)有(you)功(gong)(gong)(gong)功(gong)(gong)(gong)率(lv)下工作(zuo)(zuo)，如果功(gong)(gong)(gong)率(lv)因(yin)數(shu)較低，就(jiu)要用較大(da)(da)的電(dian)(dian)(dian)流來保障用電(dian)(dian)(dian)器(qi)正常工作(zuo)(zuo)，輸電(dian)(dian)(dian)電(dian)(dian)(dian)流變(bian)大(da)(da)，導致線路(lu)損耗增(zeng)加。此外，任(ren)何電(dian)(dian)(dian)力設備(bei)(bei)(bei)工作(zuo)(zuo)時(shi)總是工作(zuo)(zuo)在(zai)一(yi)(yi)(yi)定(ding)(ding)(ding)(ding)(ding)的額(e)定(ding)(ding)(ding)(ding)(ding)電(dian)(dian)(dian)壓(ya)(ya)與額(e)定(ding)(ding)(ding)(ding)(ding)電(dian)(dian)(dian)流內，超(chao)過(guo)(guo)額(e)定(ding)(ding)(ding)(ding)(ding)電(dian)(dian)(dian)壓(ya)(ya)值，會(hui)威(wei)脅設備(bei)(bei)(bei)的絕(jue)緣性能；工作(zuo)(zuo)電(dian)(dian)(dian)流超(chao)過(guo)(guo)額(e)定(ding)(ding)(ding)(ding)(ding)值，會(hui)使(shi)內部溫升過(guo)(guo)高(gao)，從而(er)降低了設備(bei)(bei)(bei)的使(shi)用壽命。對于一(yi)(yi)(yi)些發電(dian)(dian)(dian)設備(bei)(bei)(bei)而(er)言，功(gong)(gong)(gong)率(lv)因(yin)數(shu)的提(ti)(ti)高(gao)能大(da)(da)大(da)(da)增(zeng)加效(xiao)率(lv)，例如：一(yi)(yi)(yi)臺發電(dian)(dian)(dian)機(ji)容量為(wei)1500kW，當電(dian)(dian)(dian)力系統的功(gong)(gong)(gong)率(lv)因(yin)數(shu)由0.6上(shang)升至0.8時(shi)，就(jiu)可以使(shi)實(shi)際發電(dian)(dian)(dian)能力提(ti)(ti)高(gao)到3000kW。

5 無功補償的經濟(ji)效益

無功補償的(de)經濟效益(yi)主(zhu)要體現在力率電費(fei)，力率電費(fei)=有(you)功(gong)電量(liang)×電價×力率電費(fei)調(diao)整系(xi)數(shu)。力率電費(fei)調(diao)整系(xi)數(shu)根(gen)據(ju)功(gong)率因數(shu)的(de)值查表獲得。不同基準的(de)力率電費(fei)調(diao)整系(xi)數(shu)表見表1和表2。

表1 以0.90為標準值得力(li)率電費調整表

表(biao)2 以0.85為(wei)標準值得力率電(dian)費調(diao)整表(biao)

國(guo)家對標準(zhun)值也做(zuo)出了規(gui)定，凡需(xu)變壓器容量100kVA及以上10kV供電的用戶應(ying)進行功率(lv)因(yin)數考核，具體標準(zhun)如下：

♦ 100kVA以上160kVA（不含(han)160kVA）以下的用(yong)戶，功率因數需達到0.85；

♦ 160kVA以(yi)(yi)上的用戶功率因(yin)數(shu)應達到0.90以(yi)(yi)上。

♦ 用(yong)戶的功率因(yin)數大于(yu)標準的減少其(qi)當月電費(fei)，低(di)于(yu)標準的增加(jia)其(qi)當月電費(fei)。

舉(ju)個例子(zi)：某(mou)變(bian)(bian)壓器(qi)(qi)用(yong)(yong)(yong)戶(hu)的變(bian)(bian)壓器(qi)(qi)容量(liang)(liang)為(wei)160kVA，采用(yong)(yong)(yong)低(di)壓計量(liang)(liang)，某(mou)月改用(yong)(yong)(yong)戶(hu)消(xiao)耗(hao)有(you)(you)功電(dian)(dian)量(liang)(liang)為(wei)25000kWH，無功電(dian)(dian)量(liang)(liang)為(wei)27000kWH，假設電(dian)(dian)費為(wei)0.68元(yuan)/度。通過(guo)調研資料(liao)，該變(bian)(bian)壓器(qi)(qi)的有(you)(you)功變(bian)(bian)損為(wei)1036kWH，無功變(bian)(bian)損為(wei)3790kWH，所以該用(yong)(yong)(yong)戶(hu)共消(xiao)耗(hao)有(you)(you)功電(dian)(dian)量(liang)(liang)26036kWH，消(xiao)耗(hao)無功電(dian)(dian)量(liang)(liang)為(wei)30790kWH，通過(guo)功率三角形或查表(biao)可知(zhi)該用(yong)(yong)(yong)戶(hu)的功率因數為(wei)0.65。通過(guo)查表(biao)可知(zhi)該用(yong)(yong)(yong)戶(hu)力率電(dian)(dian)費調整系數為(wei)+15%，共需(xu)收(shou)(shou)取實際消(xiao)耗(hao)電(dian)(dian)費25000×0.68為(wei)17000元(yuan)，需(xu)加收(shou)(shou)的力率電(dian)(dian)費為(wei)25000×0.68×0.15為(wei)2550元(yuan)，總計為(wei)19550元(yuan)。

現(xian)通(tong)過無功功率補償為(wei)該(gai)用戶(hu)將功率因數從0.65提高到0.95，通(tong)過查(cha)表可知該(gai)用戶(hu)力率電費(fei)調(diao)整系數為(wei)-0.75%，共需收取實際消(xiao)耗電費(fei)25000×0.68為(wei)17000元(yuan)(yuan)，需加收的力率電費(fei)為(wei)25000×0.68×（-0.0075）為(wei)-127.5元(yuan)(yuan)，總計(ji)為(wei)16872.5元(yuan)(yuan)。

從例子中(zhong)我們(men)可(ke)(ke)以(yi)看出，通過無功補償能為企(qi)業(ye)產生很大的(de)經濟效益，一般(ban)10個月到一年即可(ke)(ke)收(shou)回(hui)裝備(bei)成本(ben)，為企(qi)業(ye)創造收(shou)入。

結束語

得潤電氣從低壓無功功率補償裝置的基本知識、選型參數、經濟效益、實例設計等方面對低壓(ya)無功功率補(bu)償裝置的設計與選型進(jin)行了闡述。提出(chu)了模塊式低(di)壓無功(gong)功(gong)率(lv)(lv)(lv)補(bu)(bu)償(chang)(chang)裝(zhuang)(zhuang)置的新思路。合理地(di)配置低(di)壓無功(gong)功(gong)率(lv)(lv)(lv)補(bu)(bu)償(chang)(chang)裝(zhuang)(zhuang)置不僅能(neng)為降低(di)線(xian)損、提高設備壽命與運行效(xiao)率(lv)(lv)(lv)，更能(neng)夠為企業減少(shao)力率(lv)(lv)(lv)罰款，獲得電費獎勵，直觀(guan)的創造經濟效(xiao)益。

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