聯(lian)系電話：13917768445
聯(lian)系電話：13917768445
淺談SJD-YD低壓電機保護器的應用原理
1.引言
鋼(gang)鐵(tie)制造業電機(ji)設備屬于大(da)容量、高負荷(he)值而燒毀的(de)連續(xu)運轉(zhuan)。因而對其可靠性(xing)和穩定性(xing)要求極高,一旦發生(sheng)事(shi)故,必須馬上查找故障原因并及時(shi)消除,以保證及時(shi)恢復生(sheng)產。為(wei)此,經過多年嘗試和反復實踐。最終選擇(ze)了電動(dong)機(ji)智能保護器簡稱為(wei)電機(ji)保護器,作(zuo)(zuo)為(wei)電動(dong)機(ji)的(de)保護元(yuan)件,下(xia)面就電動(dong)機(ji)的(de)故障原因以及電機(ji)保護器的(de)應用作(zuo)(zuo)一簡單介(jie)紹。
2、電動機的故障原因
電動機在運行中由(you)于(yu)種(zhong)種(zhong)原(yuan)因。會出(chu)現故障(zhang),故障(zhang)分機械(xie)與電氣兩(liang)方面。
2.1 機械方面有掃膛、振動、軸承過熱等故障
2.2 電氣方面主要是電動機繞組過熱。超過額定值而燒毀
這里(li)我們僅(jin)對(dui)電(dian)(dian)(dian)(dian)氣(qi)故障(zhang)進行分(fen)析,造成繞(rao)(rao)組過(guo)(guo)熱(re)的主要(yao)原(yuan)因之一是流(liu)(liu)過(guo)(guo)繞(rao)(rao)組的電(dian)(dian)(dian)(dian)流(liu)(liu)過(guo)(guo)大,超(chao)(chao)(chao)過(guo)(guo)電(dian)(dian)(dian)(dian)動機(ji)(ji)的額(e)(e)定(ding)電(dian)(dian)(dian)(dian)流(liu)(liu)。造成繞(rao)(rao)組過(guo)(guo)熱(re)的主要(yao)原(yuan)因之二(er):雖(sui)然流(liu)(liu)過(guo)(guo)繞(rao)(rao)組的電(dian)(dian)(dian)(dian)流(liu)(liu)不(bu)超(chao)(chao)(chao)過(guo)(guo)額(e)(e)定(ding)值,但由(you)于電(dian)(dian)(dian)(dian)機(ji)(ji)通風不(bu)良(liang)或環境(jing)溫(wen)度過(guo)(guo)高。繞(rao)(rao)組的發熱(re)不(bu)能及時散(san)出,也能造成繞(rao)(rao)組溫(wen)度超(chao)(chao)(chao)過(guo)(guo)額(e)(e)定(ding)值而燒(shao)毀(hui)電(dian)(dian)(dian)(dian)機(ji)(ji)。
3、電機保護器的組成與功能
3.1 電機保護器的組成
電機保護器集過輕載保護、缺相、過欠壓、堵轉、漏電、接地及三相不平衡保護等低壓保護于一身,通常由電流互感器、比較電路、單片機或出口繼電器等幾部分組成。
3.2 電機保護器的功能
3.2.1 系統保護功能
電機保護器可實現對電機的綜合保護,具體功能有接地保護、斷相保護、短路保護、過（輕）負荷保護、不平衡過負荷保護、堵轉保護、低電壓和過電壓保護。當電機正常工作時,保護器通過面板上的液晶顯示屏.實時顯示電機的工作電流和電壓。具有通訊功能的電機保護器定時將采集的信號通過CAN總線傳至后臺微
嵌人式安裝開關抽屜活動面板內,這樣既簡化
機。當故障發生時,保護器能自動地、迅速地反應并發出跳閘信號。
3.2.2 故障判斷與記憶功能
電機保護器對電動機進行檢測時。需正確判斷電動機正常、過載、短路、斷相、過壓、欠壓、過熱等工況并作相應的處理。當電動機出現某種故障時,保護器切斷電動機的電源而處于保護狀態,并且保存故障類型、時間以及電機運行參數。電機保護器通過識別與記憶電路對故障予以識別、記憶和指示,以便于維修。只有故障
排除后,復位保護器,故障指示才消失,電動機才能再次啟動。
3.2.3 在線監測功能
帶有通訊功能的電機保護器使控制室操作人員可在后臺微機上,完成所有保護器的各種保護整定數據的調閱、修改和整定。同時。在線監測電機的運行負載和供電電源的質量.為及早發現過載和接地故障等創造了條件。此外,后臺微機強大的信息管理功能。可有效記錄各臺電機的型號、運行方式和歷史維護記錄,為保證工藝系統的安全生產、減少事故停車提供了可靠依據。
4、電機保護器的應用
4.1 選型原則
電機(ji)保護器的應用首先要做到正確的選型(xing)。必須考慮以下幾個方面(mian)。
4.1.1 電機保護器按結構形式來劃分
一般分為一體式和分體式兩種。所謂一體式就是顯示面板與電流互感器部分是一體式,分體式就是顯示面板與電流互感器部分是分開的。我們在項目實踐中:前者是獨立整體。故適合于固定柜安裝.如GGD柜。可將保護器直接固定安裝面板上,饋出電纜穿芯即可。后者互感器部分與顯示部分分為兩體,可一定范圍內任意安置,故非常適合于新型抽屜式開關柜安裝。很多項目中普遍采用低壓抽屜式開關柜,創造性將顯示表頭了柜內接線,又方便了系統隨時調整、設定參數和顯示、監控,同時數字化顯示面板也增添了柜面統一性和美觀性;使配電室內設備運行情況及故障狀態一目了然,極大方便了系統巡視和檢修維護。
4.1.2 電機保護器按額定工作電壓及電流范圍來劃分
可(ke)分為(wei)AC380V、AC220V兩種;對應量(liang)程(cheng)為(wei)5A、10A.30A、50A、100A、200A、300A、400A等若干等級(ji),使用時按照電(dian)機(ji)控制回路工作電(dian)壓(ya)及負載的額定電(dian)流選用相(xiang)應的量(liang)程(cheng)范(fan)圍即可(ke)。
在工程應用中,由于電機較多。為方便互換及減少備件的種類,對于及200A以下的電機,用分體式電機保護器.使主回路的一次電纜直接穿過電機保護器的電流互感器部分即可實現小功率電動機的控制和保護; 200A以上的電機.一般采用在主回路裝設3個變比為5A的電流互感器的方式.將一次電流變為小于5A的二次電流,再接入電機保護器,使大型設備也得到了有效的控制和保護。
4.1.3 電機保護器除了具備基本保護功能外,
一般還具備RS485通訊接口,可根據工藝以及DCS系統聯鎖的實際需要合理安裝:零序漏電保護功能,電動機自動重啟動功能。當供配電系統發生電壓驟降,而且又在設定的自動重啟動時間內恢復正常。電機保護器可以將停運的電機主
動機在設定的時間自動恢復至運行狀態。這些非標配的功能在選型時要根據用戶要求合理配。
4.2應用實例障
下面以SJD-YD系列電機保護器為例,介紹電機保護器在我公司項目的應用情況。
4.2.1 SJD-YD分體式電機保護器在18.5KW原煤輸送收塵器風機回路中的應用
圖1 SJD-YD電機保護器的二次原理圖
應用電(dian)機(ji)(ji)保(bao)(bao)(bao)護(hu)器(qi)(qi)(qi)(qi)的(de)二次原(yuan)理圖見(jian)圖1。其工藝原(yuan)理:合上開(kai)關(guan)QF和(he)微(wei)動(dong)(dong)(dong)開(kai)關(guan)QF1,按(an)下(xia)場(chang)按(an)鈕SB1,接(jie)(jie)(jie)觸(chu)(chu)器(qi)(qi)(qi)(qi)KM線圈帶電(dian)并通(tong)(tong)過(guo)其輔(fu)助接(jie)(jie)(jie)點自(zi)保(bao)(bao)(bao)持,接(jie)(jie)(jie)觸(chu)(chu)器(qi)(qi)(qi)(qi)觸(chu)(chu)點動(dong)(dong)(dong)作,主回路接(jie)(jie)(jie)通(tong)(tong),同(tong)時(shi)柜上紅燈HR1和(he)現(xian)場(chang)紅燈HR2發(fa)光(guang),電(dian)機(ji)(ji)保(bao)(bao)(bao)護(hu)器(qi)(qi)(qi)(qi)顯示運行狀態。電(dian)動(dong)(dong)(dong)機(ji)(ji)啟動(dong)(dong)(dong)。如果電(dian)動(dong)(dong)(dong)機(ji)(ji)出(chu)現(xian)故(gu)(gu)障(zhang),電(dian)機(ji)(ji)保(bao)(bao)(bao)護(hu)器(qi)(qi)(qi)(qi)的(de)保(bao)(bao)(bao)護(hu)接(jie)(jie)(jie)點3、4動(dong)(dong)(dong)作, 使接(jie)(jie)(jie)觸(chu)(chu)器(qi)(qi)(qi)(qi)KM線圈失電(dian),跳開(kai)接(jie)(jie)(jie)觸(chu)(chu)器(qi)(qi)(qi)(qi)觸(chu)(chu)點，同(tong)時(shi)柜上綠(lv)燈HG1和(he)現(xian)場(chang)綠(lv)燈HG2發(fa)光(guang)，電(dian)機(ji)(ji)保(bao)(bao)(bao)護(hu)器(qi)(qi)(qi)(qi)的(de)輸出(chu)故(gu)(gu)障(zhang)接(jie)(jie)(jie)點5、6動(dong)(dong)(dong)作，發(fa)出(chu)故(gu)(gu)障(zhang)報警(jing)信號，柜上故(gu)(gu)障(zhang)燈HY也會發(fa)光(guang)。電(dian)機(ji)(ji)保(bao)(bao)(bao)護(hu)器(qi)(qi)(qi)(qi)通(tong)(tong)過(guo)判斷與記(ji)憶(yi)，自(zi)保(bao)(bao)(bao)持并顯示故(gu)(gu)障(zhang)狀態，并將電(dian)機(ji)(ji)保(bao)(bao)(bao)護(hu)器(qi)(qi)(qi)(qi)通(tong)(tong)訊(xun)接(jie)(jie)(jie)口9、10端子輸出(chu)的(de)信號傳(chuan)送到電(dian)氣(qi)控制室后(hou)臺計算機(ji)(ji)，直到運行人員(yuan)查(cha)明(ming)故(gu)(gu)障(zhang)后(hou)，在后(hou)臺計算機(ji)(ji)或電(dian)機(ji)(ji)保(bao)(bao)(bao)護(hu)器(qi)(qi)(qi)(qi)的(de)面板上按(an)復(fu)位鍵(jian)后(hou)機(ji)(ji)內(nei)出(chu)口繼電(dian)器(qi)(qi)(qi)(qi)才可以復(fu)位，為再次啟動(dong)(dong)(dong)做好準備。
4.2.2 帶漏電保護功能的SJD-YD分體式電機保護器在132kw電機回路中的應用
圖2 SJD-YD電機保護器的二次原理圖
如圖(tu)(tu)2所示(shi)，7、8端子為保(bao)(bao)(bao)(bao)(bao)(bao)護(hu)(hu)(hu)(hu)器(qi)(qi)的(de)(de)(de)輸(shu)出零序(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)互(hu)感(gan)(gan)器(qi)(qi)接(jie)點(dian)，其他端子與圖(tu)(tu)1一樣。由于(yu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)機(ji)(ji)(ji)功率很大，因此在(zai)主(zhu)回(hui)路配置(zhi)3個(ge)變比為5A的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)互(hu)感(gan)(gan)器(qi)(qi)，并把(ba)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)互(hu)感(gan)(gan)器(qi)(qi)的(de)(de)(de)二(er)次線穿過分體式電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)保(bao)(bao)(bao)(bao)(bao)(bao)護(hu)(hu)(hu)(hu)器(qi)(qi)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)互(hu)感(gan)(gan)器(qi)(qi)部分，然后(hou)通(tong)過保(bao)(bao)(bao)(bao)(bao)(bao)護(hu)(hu)(hu)(hu)器(qi)(qi)分體線把(ba)主(zhu)機(ji)(ji)(ji)顯(xian)示(shi)部分和互(hu)感(gan)(gan)器(qi)(qi)相連(lian)。其電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)保(bao)(bao)(bao)(bao)(bao)(bao)護(hu)(hu)(hu)(hu)器(qi)(qi)正(zheng)常工作原理(li)(li)(li)及(ji)標配故(gu)障(zhang)處理(li)(li)(li)與圖(tu)(tu)1一樣，不(bu)(bu)同之(zhi)處是本圖(tu)(tu)用到(dao)(dao)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)保(bao)(bao)(bao)(bao)(bao)(bao)護(hu)(hu)(hu)(hu)器(qi)(qi)具有零序(xu)漏(lou)(lou)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)保(bao)(bao)(bao)(bao)(bao)(bao)護(hu)(hu)(hu)(hu)功能，帶有零序(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)互(hu)感(gan)(gan)器(qi)(qi)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)機(ji)(ji)(ji)主(zhu)回(hui)路的(de)(de)(de)一次電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)纜A、B、C三相。要同時穿過電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)保(bao)(bao)(bao)(bao)(bao)(bao)護(hu)(hu)(hu)(hu)器(qi)(qi)的(de)(de)(de)零序(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)互(hu)感(gan)(gan)器(qi)(qi),依據A、B、C三選(xuan)相電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)之(zhi)和等于(yu)零的(de)(de)(de)原則(ze)來(lai)判斷零序(xu)漏(lou)(lou)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu),繼而進行漏(lou)(lou)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)保(bao)(bao)(bao)(bao)(bao)(bao)護(hu)(hu)(hu)(hu)。如果電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)機(ji)(ji)(ji)出現漏(lou)(lou)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)故(gu)障(zhang)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)保(bao)(bao)(bao)(bao)(bao)(bao)護(hu)(hu)(hu)(hu)器(qi)(qi)監測(ce)到(dao)(dao)漏(lou)(lou)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)很小.并且(qie)在(zai)漏(lou)(lou)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)允許的(de)(de)(de)范圍內（≤30mA）,電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)保(bao)(bao)(bao)(bao)(bao)(bao)護(hu)(hu)(hu)(hu)器(qi)(qi)的(de)(de)(de)輸(shu)出保(bao)(bao)(bao)(bao)(bao)(bao)護(hu)(hu)(hu)(hu)接(jie)點(dian)3、4不(bu)(bu)動(dong)(dong)作,但是電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)保(bao)(bao)(bao)(bao)(bao)(bao)護(hu)(hu)(hu)(hu)器(qi)(qi)的(de)(de)(de)顯(xian)示(shi)面(mian)板(ban)的(de)(de)(de)故(gu)障(zhang)指示(shi)燈閃爍,并將信號傳送到(dao)(dao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)氣控制室后(hou)臺(tai)計算機(ji)(ji)(ji)。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)保(bao)(bao)(bao)(bao)(bao)(bao)護(hu)(hu)(hu)(hu)器(qi)(qi)通(tong)過判斷與記憶,自保(bao)(bao)(bao)(bao)(bao)(bao)持并顯(xian)示(shi)故(gu)障(zhang)狀態,直到(dao)(dao)運(yun)行人員查明漏(lou)(lou)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)故(gu)障(zhang)并消除后(hou),在(zai)后(hou)臺(tai)計算機(ji)(ji)(ji)或(huo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)保(bao)(bao)(bao)(bao)(bao)(bao)護(hu)(hu)(hu)(hu)器(qi)(qi)的(de)(de)(de)面(mian)板(ban)上(shang)按(an)復(fu)位鍵后(hou)機(ji)(ji)(ji)內的(de)(de)(de)出口(kou)繼電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)才可(ke)以復(fu)位,電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)保(bao)(bao)(bao)(bao)(bao)(bao)護(hu)(hu)(hu)(hu)器(qi)(qi)顯(xian)示(shi)運(yun)行。如果電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)機(ji)(ji)(ji)出現漏(lou)(lou)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)故(gu)障(zhang),并且(qie)超出漏(lou)(lou)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)允許的(de)(de)(de)范圍,電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)保(bao)(bao)(bao)(bao)(bao)(bao)護(hu)(hu)(hu)(hu)器(qi)(qi)的(de)(de)(de)輸(shu)出保(bao)(bao)(bao)(bao)(bao)(bao)護(hu)(hu)(hu)(hu)接(jie)點(dian)3、4動(dong)(dong)作,其原理(li)(li)(li)與上(shang)圖(tu)(tu)1的(de)(de)(de)故(gu)障(zhang)處理(li)(li)(li)原理(li)(li)(li)一樣。
內容來自上海碩(shuo)吉電器有限(xian)公司htjclj.cn轉載請(qing)標明出處.
