早期(qi)低(di)壓智能混合無功補償裝置的(de)技(ji)術(shu)性能與可靠性不能滿足(zu)運行(xing)要求,目(mu)前的(de)產(chan)品(pin)已做了許(xu)多改(gai)進和提高,從產(chan)品(pin)的(de)運行(xing)情況可以反映出(chu)這(zhe)個問題,目(mu)前徐州(zhou)地區(qu)許(xu)多2000年(nian)投運的(de)產(chan)品(pin)還在安全運行(xing),運行(xing)壽命已超過8年(nian)。
低壓(ya)智能混合無(wu)功(gong)補償(chang)裝置的運行可(ke)靠性也是制造廠家比較重(zhong)視(shi)的問(wen)題,目前的低壓(ya)智能混合無(wu)功(gong)補償(chang)裝置采(cai)取了(le)不少技術(shu)措(cuo)施(shi)進行了(le)完善,現以10 kV和400 V低壓(ya)智能混合無(wu)功(gong)補償(chang)裝置為例(li),從(cong)以下三個因素著手(shou)分析。
低壓智能混合無功補(bu)償裝(zhuang)置技(ji)術(shu)性能分析
構(gou)成新(xin)型低壓智(zhi)能混合無功補(bu)償裝置的(de)主(zhu)要元(yuan)(yuan)件有:主(zhu)體(ti)元(yuan)(yuan)件(電(dian)(dian)力(li)電(dian)(dian)容器(qi))、控制保護(hu)檢測元(yuan)(yuan)件(CPU微機控制器(qi)及電(dian)(dian)子電(dian)(dian)路元(yuan)(yuan)件)、投切元(yuan)(yuan)件(開關等電(dian)(dian)工(gong)元(yuan)(yuan)件)3個(ge)部分。
a. 電(dian)(dian)力電(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)。近年來(lai)制造廠家(jia)在產(chan)品原料(liao)和(he)生產(chan)工(gong)藝上(shang)都(dou)做(zuo)了明顯的(de)(de)改進,如10 kV電(dian)(dian)力電(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)以全膜(mo)或膜(mo)紙(zhi)(zhi)介質(zhi)代替了過(guo)去(qu)(qu)的(de)(de)紙(zhi)(zhi)介質(zhi),以去(qu)(qu)毒化(hua)十二烷基苯代替了過(guo)去(qu)(qu)的(de)(de)氯化(hua)聯苯,采(cai)用(yong)(yong)了抽真(zhen)(zhen)空(kong)密封的(de)(de)工(gong)藝技術等,使電(dian)(dian)力電(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)的(de)(de)質(zhi)量和(he)壽(shou)命有了大幅(fu)度(du)的(de)(de)提高。另外(wai)還采(cai)取了集(ji)合式(shi)組(zu)裝形式(shi),可在室外(wai)安裝使用(yong)(yong),節(jie)(jie)約了占地(di)面積(ji),節(jie)(jie)省了投資(zi)。400 V電(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)也采(cai)取了抽真(zhen)(zhen)空(kong)密封工(gong)藝,并生產(chan)出自愈式(shi)金(jin)屬化(hua)薄(bo)膜(mo)電(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)等產(chan)品來(lai)提高其可靠(kao)性。但由(you)于產(chan)品本身的(de)(de)性質(zhi)和(he)結構上(shang)的(de)(de)原因(如電(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)在絕緣(yuan)結構上(shang)要形成分層絕緣(yuan)),它(ta)在絕緣(yuan)方(fang)面的(de)(de)可靠(kao)性不(bu)(bu)能與開(kai)關、絕緣(yuan)支柱(zhu)等元件相比,在運行時操作不(bu)(bu)當會(hui)在電(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)中(zhong)產(chan)生涌流(liu),從而對(dui)電(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)產(chan)生不(bu)(bu)良(liang)影響。
b. 微機(ji)控制元(yuan)(yuan)(yuan)件(jian)及電(dian)(dian)(dian)(dian)(dian)子電(dian)(dian)(dian)(dian)(dian)路元(yuan)(yuan)(yuan)件(jian)。隨著電(dian)(dian)(dian)(dian)(dian)子技(ji)術的(de)(de)飛(fei)躍發展(zhan),這(zhe)些元(yuan)(yuan)(yuan)件(jian)已(yi)有(you)較(jiao)高的(de)(de)可(ke)(ke)靠性及較(jiao)長的(de)(de)壽命(ming)。根據使用(yong)(yong)(yong)(yong)環境的(de)(de)不(bu)同,這(zhe)些元(yuan)(yuan)(yuan)件(jian)的(de)(de)技(ji)術等級(ji)有(you)明顯的(de)(de)區別,大致可(ke)(ke)分(fen)為軍用(yong)(yong)(yong)(yong)、工業(ye)用(yong)(yong)(yong)(yong)、民用(yong)(yong)(yong)(yong)及普通4個等級(ji)。低壓(ya)(ya)智(zhi)能混合(he)無功補償(chang)裝置應采用(yong)(yong)(yong)(yong)工業(ye)用(yong)(yong)(yong)(yong)的(de)(de)電(dian)(dian)(dian)(dian)(dian)子電(dian)(dian)(dian)(dian)(dian)路元(yuan)(yuan)(yuan)件(jian)。在電(dian)(dian)(dian)(dian)(dian)子電(dian)(dian)(dian)(dian)(dian)路元(yuan)(yuan)(yuan)件(jian)中集成電(dian)(dian)(dian)(dian)(dian)路及其他半(ban)導(dao)體(ti)器(qi)(qi)件(jian)和電(dian)(dian)(dian)(dian)(dian)容(rong)器(qi)(qi)是影(ying)響可(ke)(ke)靠性的(de)(de)關鍵器(qi)(qi)件(jian),選(xuan)用(yong)(yong)(yong)(yong)時(shi)更要注(zhu)(zhu)意其級(ji)別。耐受電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)參(can)(can)數(shu)和工作溫(wen)度參(can)(can)數(shu)對于(yu)可(ke)(ke)靠性而言也比較(jiao)重(zhong)要,在具體(ti)選(xuan)擇時(shi)應注(zhu)(zhu)意留有(you)余地,耐受電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)參(can)(can)數(shu)要提高一個檔(dang)次選(xuan)用(yong)(yong)(yong)(yong),工作溫(wen)度參(can)(can)數(shu)要充分(fen)考(kao)慮環境溫(wen)度的(de)(de)影(ying)響。
c. 開關等(deng)電工(gong)(gong)元(yuan)(yuan)件(jian)。隨(sui)著制造(zao)工(gong)(gong)藝水(shui)平的大(da)幅度(du)提高和(he)國家(jia)強(qiang)制性質量認(ren)證體系的實施,400 V低壓智能混(hun)合無功補償裝置的電工(gong)(gong)元(yuan)(yuan)件(jian)的可(ke)靠性已(yi)能得到保證,選用時(shi)要(yao)選經國家(jia)3C認(ren)證的產品。
在(zai)10 kV低(di)壓智(zhi)能混合無功補(bu)償裝置中,以前(qian)的產品是用油(you)(you)斷(duan)(duan)(duan)路(lu)器來投切電容器的,不能滿足(zu)頻繁投切的需(xu)要。隨著高壓開關無油(you)(you)化技術的發(fa)展,10 kV油(you)(you)斷(duan)(duan)(duan)路(lu)器已被真(zhen)空斷(duan)(duan)(duan)路(lu)器和(he)(he)SF6斷(duan)(duan)(duan)路(lu)器替代。這(zhe)兩種斷(duan)(duan)(duan)路(lu)器的電氣壽命和(he)(he)機械(xie)壽命長,都(dou)可以滿足(zu)頻繁投切的要求。但真(zhen)空斷(duan)(duan)(duan)路(lu)器在(zai)滅弧(hu)原理上會出現截流過(guo)電壓的情況,影響(xiang)電容器的絕緣(yuan)壽命,所以以選用SF6斷(duan)(duan)(duan)路(lu)器為(wei)宜。
無論是(shi)10 kV的低(di)壓(ya)智能(neng)(neng)(neng)混合無功補償裝(zhuang)(zhuang)置還是(shi)400 V的低(di)壓(ya)智能(neng)(neng)(neng)混合無功補償裝(zhuang)(zhuang)置,在投切電容器時都可(ke)能(neng)(neng)(neng)出現(xian)涌流(liu)現(xian)象(xiang),這(zhe)對(dui)電容器來說是(shi)不利的。現(xian)在的技(ji)術(shu)已經(jing)能(neng)(neng)(neng)解決(jue)這(zhe)個問(wen)題,即利用微機控制裝(zhuang)(zhuang)置對(dui)電壓(ya)和電流(liu)波形進(jin)行分析(xi),實現(xian)“過零(ling)投切”,也就是(shi)當(dang)電壓(ya)過零(ling)點時投入電容器組,當(dang)電流(liu)過零(ling)點時切除電容器組。選擇低(di)壓(ya)智能(neng)(neng)(neng)混合無功補償裝(zhuang)(zhuang)置時,要注意對(dui)這(zhe)項技(ji)術(shu)性能(neng)(neng)(neng)的選擇。
在企業設(she)備運行過程中,如果電網(wang)負(fu)荷(he)波動(dong)較(jiao)為(wei)頻(pin)繁,并且(qie)大與小負(fu)荷(he)之(zhi)間存在相對(dui)較(jiao)大的(de)差距,用電負(fu)載(zai)以(yi)及(ji)三相負(fu)荷(he)存在極(ji)為(wei)不平(ping)衡的(de)情況下,對(dui)防爆(bao)電容(rong)器的(de)無功(gong)(gong)補償控制器則提出(chu)了更詳盡的(de)要(yao)求(qiu),控制器復合投(tou)切功(gong)(gong)能(neng)(neng)應當具備分相以(yi)及(ji)平(ping)衡兩大功(gong)(gong)能(neng)(neng)。現(xian)在施博爾為(wei)您(nin)簡單介紹一下防爆(bao)電容(rong)器無功(gong)(gong)補償控制器參(can)數設(she)定(ding)。
防爆電容(rong)器(qi)控(kong)制器(qi)參(can)數
具體參數要求(qiu):
一般情況(kuang)下防爆電(dian)容器無功補償(chang)控制器的靈敏度≤100 mA,對于(yu)動作誤(wu)差(cha)需要取樣物理量的允(yun)許(xu)誤(wu)差(cha)值來確定,例如(ru):
1.無(wu)功(gong)電流±20%;
2.功率因數±2.5%;
3.無功(gong)功(gong)率±20%。
4.穩(wen)定(ding)范(fan)圍(wei):在工作穩(wen)定(ding)之下,在補償要求滿足的(de)情況(kuang)之下,才能夠(gou)正確(que)的(de)選擇控制(zhi)器,從(cong)而(er)防止不出現投切震蕩的(de)現象(xiang)。
控制(zhi)器無功控制(zhi)要求:
在企業用(yong)電(dian)(dian)負載(zai)以及電(dian)(dian)力(li)系(xi)統中(zhong),為了(le)更好配合(he)(he)電(dian)(dian)網自(zi)動(dong)化工程的(de)實施,防爆電(dian)(dian)容器(qi)(qi)的(de)控制(zhi)器(qi)(qi)在確保(bao)功(gong)(gong)率(lv)因數(shu)得到提(ti)高(gao)的(de)前提(ti)下,還需(xu)要(yao)能夠對(dui)(dui)電(dian)(dian)網運行當中(zhong)的(de)各項(xiang)參數(shu)進(jin)行實時監控并實時顯示。對(dui)(dui)于無功(gong)(gong)補償系(xi)統中(zhong)控制(zhi)器(qi)(qi)的(de)選(xuan)擇(ze)需(xu)要(yao)考慮到綜合(he)(he)測試功(gong)(gong)能。