大容量(liang)礦熱爐直流電(dian)源設(she)計的(de)幾(ji)個關鍵問題！

礦(kuang)(kuang)熱爐(lu)是鐵合(he)金行(xing)業冶煉(lian)硅鐵、鎳鐵、鉻鐵、電(dian)(dian)石(shi)的(de)必備設(she)備，據(ju)不完全(quan)統計，全(quan)國(guo)(guo)有各種礦(kuang)(kuang)熱爐(lu)3萬多(duo)臺。長期以來，國(guo)(guo)內礦(kuang)(kuang)熱爐(lu)大(da)多(duo)采用交流供電(dian)(dian)方(fang)式(shi)，導致功率(lv)(lv)因數(shu)(shu)低(di)、電(dian)(dian)網三相很難控制平(ping)衡、效率(lv)(lv)低(di)、運行(xing)成(cheng)本高等問(wen)題(ti)一直(zhi)無(wu)法(fa)解決。相比之(zhi)下(xia)直(zhi)流電(dian)(dian)源擁(yong)有更大(da)的(de)優(you)勢，如:直(zhi)流電(dian)(dian)源可消除電(dian)(dian)抗壓降、集膚效應、電(dian)(dian)極(ji)間干(gan)擾效應等問(wen)題(ti)，并且運行(xing)損耗低(di)、電(dian)(dian)效率(lv)(lv)高。因此目前大(da)容量礦(kuang)(kuang)熱爐(lu)電(dian)(dian)源正朝著直(zhi)流供電(dian)(dian)方(fang)向發展(zhan)。文中(zhong)探(tan)討了大(da)容量礦(kuang)(kuang)熱爐(lu)直(zhi)流電(dian)(dian)源設(she)計的(de)幾個關鍵性(xing)問(wen)題(ti)，包括主電(dian)(dian)路拓撲結構選(xuan)用，均流系數(shu)(shu)優(you)化，監控系統設(she)計與(yu)功率(lv)(lv)因數(shu)(shu)提高等探(tan)索性(xing)問(wen)題(ti)。那就快來和小編(bian)一起看看吧！

大(da)電(dian)流輸(shu)出需要(yao)使(shi)用并聯(lian)器(qi)(qi)(qi)件(jian)(jian)以(yi)達到(dao)運行(xing)要(yao)求。隨著并聯(lian)器(qi)(qi)(qi)件(jian)(jian)數量的增加(jia)，出現(xian)的是均(jun)(jun)流系數低(di)的問題。因此，選用適當的主電(dian)路拓撲結構(gou)以(yi)擴大(da)系統(tong)輸(shu)出電(dian)流，達到(dao)減(jian)少并聯(lian)器(qi)(qi)(qi)件(jian)(jian)數，優化(hua)均(jun)(jun)流系數，防止器(qi)(qi)(qi)件(jian)(jian)損壞的目(mu)的顯得尤為重要(yao)。

礦(kuang)熱爐可控(kong)整(zheng)流(liu)(liu)電(dian)(dian)(dian)(dian)(dian)路(lu)的(de)(de).基本單(dan)元為(wei)三(san)(san)(san)相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)橋(qiao)式(shi)(shi)和雙(shuang)(shuang)(shuang)反星形(xing)整(zheng)流(liu)(liu)電(dian)(dian)(dian)(dian)(dian)路(lu)。單(dan)從輸出(chu)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)的(de)(de)大(da)小考慮，在(zai)并(bing)(bing)聯(lian)(lian)(lian)相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)同(tong)(tong)(tong)數量(liang)及容量(liang)的(de)(de)電(dian)(dian)(dian)(dian)(dian)力電(dian)(dian)(dian)(dian)(dian)子(zi)器(qi)(qi)件(jian)前提下(xia)，雙(shuang)(shuang)(shuang)反星形(xing)整(zheng)流(liu)(liu)電(dian)(dian)(dian)(dian)(dian)路(lu)的(de)(de)輸出(chu)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)是三(san)(san)(san)相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)橋(qiao)式(shi)(shi)整(zheng)流(liu)(liu)電(dian)(dian)(dian)(dian)(dian)路(lu)的(de)(de)2倍。但(dan)在(zai)同(tong)(tong)(tong)樣輸出(chu)電(dian)(dian)(dian)(dian)(dian)壓(ya)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)情(qing)況下(xia)，三(san)(san)(san)相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)橋(qiao)式(shi)(shi)整(zheng)流(liu)(liu)電(dian)(dian)(dian)(dian)(dian)路(lu)的(de)(de)整(zheng)流(liu)(liu)變(bian)壓(ya)器(qi)(qi)裝機容量(liang)要低于雙(shuang)(shuang)(shuang)反星形(xing)21%，同(tong)(tong)(tong)時(shi)整(zheng)流(liu)(liu)器(qi)(qi)件(jian)所承受的(de)(de)反向電(dian)(dian)(dian)(dian)(dian)壓(ya)為(wei)雙(shuang)(shuang)(shuang)反星形(xing)的(de)(de)一半，變(bian)壓(ya)器(qi)(qi)繞組(zu)利(li)用(yong)(yong)率比雙(shuang)(shuang)(shuang)反星形(xing)高(gao)一倍。因此，綜合考慮，若輸出(chu)電(dian)(dian)(dian)(dian)(dian)壓(ya)較(jiao)(jiao)高(gao)，三(san)(san)(san)相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)橋(qiao)式(shi)(shi)整(zheng)流(liu)(liu)電(dian)(dian)(dian)(dian)(dian)路(lu)擁(yong)有較(jiao)(jiao)大(da)優勢。由于礦(kuang)熱爐電(dian)(dian)(dian)(dian)(dian)源運行時(shi)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)達40~150kA，為(wei)了滿足(zu)輸出(chu)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)需(xu)求，同(tong)(tong)(tong)時(shi)降(jiang)(jiang)低電(dian)(dian)(dian)(dian)(dian)磁(ci)干擾(rao)(rao)，可用(yong)(yong)三(san)(san)(san)相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)橋(qiao)式(shi)(shi)同(tong)(tong)(tong)相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)逆(ni)(ni)并(bing)(bing)聯(lian)(lian)(lian)結(jie)(jie)(jie)(jie)構與(yu)雙(shuang)(shuang)(shuang)反星形(xing)同(tong)(tong)(tong)相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)逆(ni)(ni)并(bing)(bing)聯(lian)(lian)(lian)結(jie)(jie)(jie)(jie)構。這兩種結(jie)(jie)(jie)(jie)構與(yu)前兩種結(jie)(jie)(jie)(jie)構相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)比，擴(kuo)(kuo)大(da)了2倍輸出(chu)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)并(bing)(bing)降(jiang)(jiang)低了電(dian)(dian)(dian)(dian)(dian)磁(ci)干擾(rao)(rao)。然而這種結(jie)(jie)(jie)(jie)構很難滿足(zu)大(da)容量(liang)礦(kuang)熱爐電(dian)(dian)(dian)(dian)(dian)源超過(guo)100kA的(de)(de)輸出(chu)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)要求。為(wei)進一步擴(kuo)(kuo)大(da)輸出(chu)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)，降(jiang)(jiang)低諧波(bo)含量(liang)，提高(gao)系統功率因數，可選12脈(mo)(mo)波(bo)雙(shuang)(shuang)(shuang)反星形(xing)同(tong)(tong)(tong)相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)逆(ni)(ni)并(bing)(bing)聯(lian)(lian)(lian)結(jie)(jie)(jie)(jie)構與(yu)12脈(mo)(mo)波(bo)三(san)(san)(san)相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)橋(qiao)式(shi)(shi)同(tong)(tong)(tong)相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)逆(ni)(ni)并(bing)(bing)聯(lian)(lian)(lian)結(jie)(jie)(jie)(jie)構。12脈(mo)(mo)波(bo)三(san)(san)(san)相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)橋(qiao)式(shi)(shi)同(tong)(tong)(tong)相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)逆(ni)(ni)并(bing)(bing)聯(lian)(lian)(lian)結(jie)(jie)(jie)(jie)構的(de)(de)典(dian)型特點是:輸出(chu)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)大(da)、諧波(bo)含量(liang)少(shao)、電(dian)(dian)(dian)(dian)(dian)磁(ci)干擾(rao)(rao)小、繞組(zu)利(li)用(yong)(yong)率高(gao)、無需(xu)使(shi)用(yong)(yong)平衡(heng)電(dian)(dian)(dian)(dian)(dian)抗器(qi)(qi)等。因此在(zai)大(da)容量(liang)礦(kuang)熱爐直流(liu)(liu)電(dian)(dian)(dian)(dian)(dian)源中(zhong)，選用(yong)(yong)脈(mo)(mo)波(bo)數為(wei)12脈(mo)(mo)波(bo)及以上的(de)(de)三(san)(san)(san)相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)橋(qiao)式(shi)(shi)同(tong)(tong)(tong)相(xiang)(xiang)(xiang)(xiang)(xiang)(xiang)逆(ni)(ni)并(bing)(bing)聯(lian)(lian)(lian)結(jie)(jie)(jie)(jie)構較(jiao)(jiao)為(wei)合適。

由于(yu)電(dian)(dian)力(li)電(dian)(dian)子器(qi)件(jian)在(zai)材料及制作(zuo)工(gong)藝上(shang)的(de)不同，其性(xing)能指標也有所(suo)不同。晶(jing)閘(zha)(zha)管適合(he)應用于(yu)超大功(gong)(gong)率(lv)(lv)(lv)且工(gong)作(zuo)頻率(lv)(lv)(lv)較(jiao)低的(de)場(chang)合(he)，一(yi)方面(mian)是由于(yu)晶(jing)閘(zha)(zha)管額定參數高、控制簡單、技術成熟；另一(yi)方面(mian)是由于(yu)晶(jing)閘(zha)(zha)管具(ju)有較(jiao)高的(de)浪(lang)涌耐受能力(li)、較(jiao)高的(de)電(dian)(dian)流參數和(he)良好的(de)耐過流能力(li)，可以較(jiao)好地滿足(zu)運行(xing)需(xu)求。因此選擇晶(jing)閘(zha)(zha)管作(zuo)為(wei)電(dian)(dian)路的(de)主功(gong)(gong)率(lv)(lv)(lv)器(qi)件(jian)。

在(zai)大容量(liang)礦熱(re)爐直(zhi)流(liu)(liu)(liu)(liu)供電(dian)(dian)電(dian)(dian)源(yuan)中，不(bu)得不(bu)采用多個(ge)(ge)器(qi)件(jian)(jian)并聯(lian)的(de)(de)措施以承擔較大的(de)(de)整(zheng)(zheng)流(liu)(liu)(liu)(liu)臂電(dian)(dian)流(liu)(liu)(liu)(liu)。即使通(tong)(tong)過(guo)上述主電(dian)(dian)路拓(tuo)撲結(jie)構(gou)將175V/100kA直(zhi)流(liu)(liu)(liu)(liu)電(dian)(dian)源(yuan)的(de)(de)每個(ge)(ge)整(zheng)(zheng)流(liu)(liu)(liu)(liu)臂所需并聯(lian)晶閘(zha)管個(ge)(ge)數(shu)降至6個(ge)(ge)，仍存在(zai)嚴(yan)重的(de)(de)均(jun)流(liu)(liu)(liu)(liu)問題(ti)。在(zai)多個(ge)(ge)器(qi)件(jian)(jian)并聯(lian)的(de)(de)整(zheng)(zheng)流(liu)(liu)(liu)(liu)臂中，若均(jun)流(liu)(liu)(liu)(liu)系數(shu)過(guo)低，會(hui)出現某些器(qi)件(jian)(jian)未(wei)導(dao)通(tong)(tong)，某些器(qi)件(jian)(jian)過(guo)流(liu)(liu)(liu)(liu)的(de)(de)情況(kuang)。嚴(yan)重時燒(shao)壞器(qi)件(jian)(jian)，從而使得整(zheng)(zheng)流(liu)(liu)(liu)(liu)臂中其它支路過(guo)流(liu)(liu)(liu)(liu)，導(dao)致整(zheng)(zheng)個(ge)(ge)整(zheng)(zheng)流(liu)(liu)(liu)(liu)臂器(qi)件(jian)(jian)損壞。為解決(jue)該(gai)問題(ti)，以下(xia)提出幾(ji)點優化(hua)均(jun)流(liu)(liu)(liu)(liu)系數(shu)的(de)(de)措施。

(1)采(cai)用合適(shi)的整流臂結構

礦熱爐一(yi)般電(dian)力電(dian)子器件進(jin)入穩態正(zheng)向導(dao)通(tong)(tong)后其通(tong)(tong)態壓降很低，相應的(de)(de)(de)(de)通(tong)(tong)態電(dian)阻很小。若并聯(lian)支路(lu)(lu)母(mu)線的(de)(de)(de)(de)配置不(bu)合(he)理，則電(dian)路(lu)(lu)自感及(ji)互(hu)感的(de)(de)(de)(de)差異就會造成電(dian)流分(fen)配的(de)(de)(de)(de)不(bu)均衡。因此在工作電(dian)流較大(da)(da)的(de)(de)(de)(de)情(qing)況(kuang)下，由于(yu)支路(lu)(lu)磁場及(ji)阻抗差異的(de)(de)(de)(de)影響(xiang)，位(wei)于(yu)不(bu)同位(wei)置的(de)(de)(de)(de)器件導(dao)通(tong)(tong)時，流過的(de)(de)(de)(de)電(dian)流值(zhi)不(bu)同，且與(yu)引出母(mu)線的(de)(de)(de)(de)位(wei)置有關。目(mu)前多以母(mu)線上進(jin)下出(或下進(jin)上出)式的(de)(de)(de)(de)條形整(zheng)流臂結構(gou)為主(zhu)流，但實驗證明，這(zhe)種結構(gou)在并聯(lian)器件數(shu)大(da)(da)于(yu)4的(de)(de)(de)(de)情(qing)況(kuang)下，均流系數(shu)較低。

 為了得(de)到較好的(de)(de)(de)均流(liu)(liu)(liu)效果(guo)，將整流(liu)(liu)(liu)臂(bei)改為其他結構(gou)，使得(de)整流(liu)(liu)(liu)臂(bei)中的(de)(de)(de)每(mei)個(ge)晶閘(zha)管從交流(liu)(liu)(liu)進線(xian)到直流(liu)(liu)(liu)輸出的(de)(de)(de)路(lu)(lu)徑完全一樣，且(qie)流(liu)(liu)(liu)過(guo)每(mei)個(ge)晶閘(zha)管的(de)(de)(de)電流(liu)(liu)(liu)相互解耦，可解決因各元器(qi)件到正負母線(xian)路(lu)(lu)徑不同，導(dao)致的(de)(de)(de)各并聯支(zhi)路(lu)(lu)阻抗與磁場存(cun)在差異，所引發的(de)(de)(de)各支(zhi)路(lu)(lu)電流(liu)(liu)(liu)分配不均勻(yun)的(de)(de)(de)問題。該種整流(liu)(liu)(liu)臂(bei)結構(gou)可將各整流(liu)(liu)(liu)臂(bei)的(de)(de)(de)均流(liu)(liu)(liu)效果(guo)較常用(yong)的(de)(de)(de)直條結構(gou)有明顯改善，可以做(zuo)到理論上(shang)的(de)(de)(de)..均流(liu)(liu)(liu)。