日日摸日日碰人妻无码老牲_青柠影视西瓜视频在线观看_无码国产精品一区二区免费16_在线a人片免费观看

當前位置: 首頁 > 新聞中心 > 技術文章 > 詳細內容

工廠自動化設備如何應對雷擊的危害及做好防雷措施

萬邦智慧     2020-12-30     1440

1、雷電對電力設備、自動化設備危害性

  出現雷擊時,雷電(dian)(dian)(dian)(dian)流會沿變(bian)電(dian)(dian)(dian)(dian)站的(de)接地網(wang)散流,支線上(shang)的(de)雷電(dian)(dian)(dian)(dian)流和各(ge)點電(dian)(dian)(dian)(dian)位(wei)差(cha)(cha)異很大,連(lian)接在不同等電(dian)(dian)(dian)(dian)位(wei)地網(wang)上(shang)的(de)自動化設(she)備,如(ru)果其(qi)間有(you)電(dian)(dian)(dian)(dian)信(xin)號聯系(xi),那么超(chao)過其(qi)容許承受能力的(de)地電(dian)(dian)(dian)(dian)位(wei)差(cha)(cha)將導致設(she)備損壞(huai)。由于(yu)直擊雷放(fang)電(dian)(dian)(dian)(dian)的(de)能量通(tong)過電(dian)(dian)(dian)(dian)磁感應和靜電(dian)(dian)(dian)(dian)感應方(fang)式向四周輻(fu)射,會出現導致設(she)備過電(dian)(dian)(dian)(dian)壓(ya)放(fang)電(dian)(dian)(dian)(dian)。

顯然,這種(zhong)雷危害是大(da)面(mian)積(ji)的,變電(dian)站二次設(she)(she)備(bei)(bei)(bei)(bei)損壞多數都是由(you)此情況產生(sheng),特別是自動(dong)化設(she)(she)備(bei)(bei)(bei)(bei)對雷電(dian)等電(dian)磁脈沖和過電(dian)壓過電(dian)流的耐受(shou)(shou)能力很低,就會在設(she)(she)備(bei)(bei)(bei)(bei)的絕緣薄弱處造成(cheng)擊(ji)穿。而(er)且電(dian)力系(xi)統針對自動(dong)化設(she)(she)備(bei)(bei)(bei)(bei)防雷工(gong)作滯后,這些設(she)(she)備(bei)(bei)(bei)(bei)遭受(shou)(shou)雷擊(ji)損壞極高,后果也越(yue)來越(yue)嚴(yan)重。

近年來在電(dian)力系統中多(duo)次發(fa)生因雷電(dian)造成綜合自(zi)動(dong)(dong)化設備損環,使測控(kong)(kong)裝置(zhi)誤動(dong)(dong)、拒動(dong)(dong),或使遠動(dong)(dong)工作站(zhan)“罷工”,更嚴重的(de)將失去對(dui)無人值班站(zhan)的(de)監(jian)控(kong)(kong)而導致事故擴大。

  2、雷擊的侵入途徑有哪些?

  架空線(xian)路的雷(lei)電(dian)(dian)(dian)感應過(guo)電(dian)(dian)(dian)壓(ya)和直(zhi)擊(ji)雷(lei)過(guo)電(dian)(dian)(dian)壓(ya)形成的雷(lei)電(dian)(dian)(dian)波沿(yan)線(xian)路侵(qin)入(ru)變(bian)電(dian)(dian)(dian)站(zhan),是(shi)(shi)導致變(bian)電(dian)(dian)(dian)站(zhan)自動化設備遭受(shou)雷(lei)害的主要(yao)原因(yin),雷(lei)電(dian)(dian)(dian)波通常是(shi)(shi)通過(guo)變(bian)電(dian)(dian)(dian)站(zhan)鄰近的10kV線(xian)路侵(qin)入(ru)10kV母線(xian),再經過(guo)10kV站(zhan)用電(dian)(dian)(dian)變(bian)壓(ya)器高、低壓(ya)繞組間的靜(jing)電(dian)(dian)(dian)和電(dian)(dian)(dian)磁耦合闖入(ru)交(jiao)流(liu)屏饋電(dian)(dian)(dian)出線(xian)。

途中經過(guo)了(le)10kV線(xian)(xian)(xian)路避(bi)(bi)雷(lei)器(qi)(qi)(qi)(qi)、母線(xian)(xian)(xian)避(bi)(bi)雷(lei)器(qi)(qi)(qi)(qi)和站用(yong)變(bian)(bian)避(bi)(bi)雷(lei)器(qi)(qi)(qi)(qi)3級削峰,再經過(guo)站用(yong)變(bian)(bian)低壓(ya)(ya)(ya)出(chu)線(xian)(xian)(xian)的平(ping)波作(zuo)用(yong) 電(dian)(dian)壓(ya)(ya)(ya)幅(fu)值有所下降,但由于雷(lei)電(dian)(dian)波的電(dian)(dian)壓(ya)(ya)(ya)、能量極(ji)高(gao),且高(gao)壓(ya)(ya)(ya)避(bi)(bi)雷(lei)器(qi)(qi)(qi)(qi)等設備(bei)技術(shu)上(shang)局(ju)限性。雖然絕大部分的雷(lei)電(dian)(dian)能量都能在到達(da)自(zi)動(dong)化設備(bei)之前得以消(xiao)除,但雷(lei)電(dian)(dian)波仍可能以幅(fu)值相(xiang)對很(hen)高(gao),作(zuo)用(yong)時間很(hen)短的低能量尖峰脈沖(chong)的形(xing)式(shi),通(tong)過(guo)站用(yong)變(bian)(bian)壓(ya)(ya)(ya)器(qi)(qi)(qi)(qi)低壓(ya)(ya)(ya)側饋電(dian)(dian)出(chu)線(xian)(xian)(xian),加到采用(yong)220V交流電(dian)(dian)源(yuan)的自(zi)動(dong)化設備(bei)上(shang)。

此(ci)外,雷云(yun)在(zai)變電(dian)(dian)(dian)(dian)(dian)站附(fu)近活動(dong)時,雷云(yun)所帶強電(dian)(dian)(dian)(dian)(dian)場會以靜電(dian)(dian)(dian)(dian)(dian)感應(ying)(ying)方(fang)式在(zai)二次電(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)上感應(ying)(ying)出很(hen)高的(de)感應(ying)(ying)電(dian)(dian)(dian)(dian)(dian)壓(ya),當(dang)局部電(dian)(dian)(dian)(dian)(dian)位升(sheng)高超過(guo)一定數值,嚴重(zhong)得將(jiang)向(xiang)二次電(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)兩端(duan)的(de)設(she)備(bei)(bei)進行反擊(ji),并首(shou)先在(zai)較弱的(de)自(zi)動(dong)化設(she)備(bei)(bei)一端(duan)放電(dian)(dian)(dian)(dian)(dian),這(zhe)種放電(dian)(dian)(dian)(dian)(dian)干擾所帶來的(de)后(hou)果(guo)一般情況下會使裝(zhuang)置功能(neng)紊亂,嚴重(zhong)將(jiang)會損壞自(zi)動(dong)化系(xi)統的(de)元器件。還有(you)一種情況,就是感應(ying)(ying)雷電(dian)(dian)(dian)(dian)(dian)波(bo)通過(guo)測控裝(zhuang)置的(de)信號采(cai)集電(dian)(dian)(dian)(dian)(dian)纜(lan)(lan)入侵,以很(hen)高的(de)電(dian)(dian)(dian)(dian)(dian)壓(ya)直接加到遠動(dong)系(xi)統的(de)信號采(cai)集模塊(kuai)上,造成采(cai)集模塊(kuai)燒壞。因(yin)而(er)有(you)必要采(cai)取(qu)防護(hu)措施(shi),減少(shao)雷擊(ji)對設(she)備(bei)(bei)的(de)危害。

  3、自動化設備如何就應對雷擊的做好防護措施?

  應該說,變電站(zhan)傳(chuan)統防雷措施對(dui)高壓(ya)電氣設備(bei)的(de)(de)防護(hu)是(shi)有效的(de)(de),但對(dui)電子(zi)設備(bei)特別是(shi)綜(zong)合(he)自動化(hua)設備(bei)的(de)(de)防護(hu)并不(bu)充分。為了適應自動化(hua)變電站(zhan)的(de)(de)發展要求(qiu),必(bi)須在傳(chuan)統防雷措施基礎上,進(jin)(jin)一步進(jin)(jin)行有針對(dui)性的(de)(de)防護(hu),使變電站(zhan)綜(zong)合(he)自動化(hua)設備(bei)得到有效的(de)(de)保護(hu)。

  3.1、在自動化設備供電電源安裝浪涌保護器(SPD)

  電(dian)源回路(lu)是雷電(dian)流(liu)最(zui)容易進入的(de)通道,因此這是自動化設(she)備防(fang)(fang)止(zhi)雷電(dian)損壞(huai)的(de)一道重(zhong)要防(fang)(fang)線。在站用變低壓側至交(jiao)流(liu)配電(dian)屏的(de)三根相線進線側安裝具有相對(dui)地、中性線對(dui)地保護模式的(de)第(di)一級(開關型(xing))和第(di)二級(限壓型(xing))組合型(xing)交(jiao)流(liu)電(dian)源SPD。此類防(fang)(fang)雷器耐受沖(chong)擊(ji)電(dian)流(liu)不(bu)小(xiao)于(yu)20kA(10/350μs)。而在直(zhi)流(liu)屏的(de)直(zhi)流(liu)母線輸出端安裝具有正極(ji)對(dui)地、負極(ji)對(dui)地保護模式的(de)標稱放(fang)電(dian)電(dian)流(liu)不(bu)小(xiao)于(yu)10kA(8/20μs)的(de)直(zhi)流(liu)SPD。

SPD能在最短時(shi)(shi)(shi)間(jian)釋放(fang)電(dian)(dian)(dian)路(lu)(lu)上因感應(ying)雷(lei)擊(ji)而(er)產生的(de)(de)大量脈沖(chong)能量到(dao)接地網上,從而(er)保護電(dian)(dian)(dian)路(lu)(lu)上的(de)(de)設(she)備。其工作原(yuan)理如下:在正常(chang)情況下,防(fang)雷(lei)器(qi)(qi)處(chu)于高阻狀態(tai),當電(dian)(dian)(dian)源(yuan)由于雷(lei)擊(ji)或開關操(cao)作出現瞬時(shi)(shi)(shi)脈沖(chong)電(dian)(dian)(dian)壓(ya)時(shi)(shi)(shi) 防(fang)雷(lei)器(qi)(qi)立即(ji)在納秒級(ji)時(shi)(shi)(shi)間(jian)內導通,將該脈沖(chong)電(dian)(dian)(dian)壓(ya)短路(lu)(lu)到(dao)大地泄放(fang),從而(er)保護連接與電(dian)(dian)(dian)源(yuan)上的(de)(de)設(she)備。但(dan)該脈沖(chong)電(dian)(dian)(dian)壓(ya)流(liu)過防(fang)雷(lei)器(qi)(qi)后,防(fang)雷(lei)器(qi)(qi)又變為高阻狀態(tai),從而(er)不影(ying)響自動化設(she)備的(de)(de)供電(dian)(dian)(dian)。其主要作用(yong)是防(fang)感應(ying)雷(lei)過電(dian)(dian)(dian)壓(ya)和防(fang)雷(lei)電(dian)(dian)(dian)波的(de)(de)入(ru)侵。

  3.2、對自動化信號采集回路進行隔離

  變電站自動(dong)化系統開關量的輸(shu)入主要是斷路器(qi)、隔離(li)(li)開關的輔助觸點等。這些斷路器(qi)和隔離(li)(li)開關都處于室外,如果與自動(dong)化設備直接相連(lian),在雷擊時必(bi)然會引(yin)起(qi)強(qiang)的電磁涌流干擾。因此,要通過光耦合隔離(li)(li)或繼電器(qi)隔離(li)(li)才能取得比較好的效果。

開關量輸(shu)入(ru)回路前及信號變換部分應(ying)考(kao)(kao)慮(lv)采用隔(ge)離(li)器(qi),開關量輸(shu)入(ru)信號送給測控(kong)裝(zhuang)置之前必須進(jin)行(xing)隔(ge)離(li)處理,可采用光電(dian)隔(ge)離(li)器(qi),這樣可有效防止感應(ying)電(dian)壓(ya)對測控(kong)裝(zhuang)置的(de)直接損壞。此方式(shi)在綜(zong)合(he)自動化系統設(she)計時進(jin)行(xing)考(kao)(kao)慮(lv),或在設(she)備訂購時要求廠家加裝(zhuang)隔(ge)離(li)裝(zhuang)置的(de)方式(shi)比較可行(xing)。

  3.3、對自動化設備接地系統進行改進

  在變(bian)電(dian)(dian)站中(zhong)一次系(xi)統接地是防雷(lei)和(he)保證安全(quan)(系(xi)統中(zhong)性點接地)為目(mu)的(de)(de),但它對自動化(hua)系(xi)統的(de)(de)防雷(lei)也有重要的(de)(de)影響(xiang)。如(ru)果接地合適可以減少站內的(de)(de)高(gao)(gao)頻瞬時電(dian)(dian)壓幅值,特別(bie)是減少設備中(zhong)各點的(de)(de)瞬時電(dian)(dian)位差,減低(di)了遠動設備瞬時電(dian)(dian)位升高(gao)(gao)。

改進(jin)的(de)(de)方法(fa)是在(zai)變電(dian)站主控室電(dian)纜(lan)溝敷設不(bu)小于100mm2的(de)(de)銅(tong)(tong)(tong)排(pai)并延伸至(zhi)接地(di)網連接;自動化屏(ping)柜內設置專用的(de)(de)接地(di)銅(tong)(tong)(tong)排(pai),其(qi)截面不(bu)得(de)小于100mm2,且屏(ping)內的(de)(de)接地(di)銅(tong)(tong)(tong)排(pai)就(jiu)近用不(bu)小于100mm2銅(tong)(tong)(tong)導(dao)線(xian)接到二次接地(di)銅(tong)(tong)(tong)排(pai)上;各種防雷器的(de)(de)接地(di)線(xian)就(jiu)近引接至(zhi)屏(ping)內的(de)(de)接地(di)銅(tong)(tong)(tong)排(pai)。這(zhe)一(yi)措施這(zhe)對自動化設備的(de)(de)限制瞬(shun)態過電(dian)壓很有好(hao)處,實施以來效果(guo)令人滿意。

  3.4、對自動化設備進行屏蔽

  變電(dian)站自(zi)動化(hua)裝置所采集的(de)模擬(ni)量(liang),大(da)多數來自(zi)一(yi)次系統的(de)電(dian)壓互感器(qi)和電(dian)流(liu)互感器(qi),它們均處于(yu)強電(dian)回路中,直接(jie)(jie)輸入到自(zi)動化(hua)系統,在(zai)雷(lei)電(dian)時很容易(yi)對(dui)自(zi)動化(hua)設(she)備造成(cheng)干(gan)擾,設(she)計時要考慮到采用(yong)屏(ping)(ping)(ping)蔽電(dian)纜(lan),在(zai)工程(cheng)實(shi)施中所用(yong)的(de)線(xian)纜(lan)必須有隔離層(ceng)和屏(ping)(ping)(ping)蔽層(ceng),在(zai)屏(ping)(ping)(ping)蔽層(ceng)安(an)全接(jie)(jie)地(di)(di),而(er)且屏(ping)(ping)(ping)蔽層(ceng)是在(zai)兩(liang)端(duan)接(jie)(jie)地(di)(di),有其他(ta)剩余纜(lan)芯時,不(bu)要出現兩(liang)端(duan)接(jie)(jie)地(di)(di)情況(kuang),這(zhe)樣可起電(dian)場屏(ping)(ping)(ping)蔽作(zuo)用(yong),防(fang)止雷(lei)電(dian)電(dian)磁脈沖感應自(zi)動化(hua)線(xian)纜(lan)而(er)造成(cheng)設(she)備損(sun)壞,另外(wai)對(dui)已投入運行(xing)的(de)自(zi)動化(hua)屏(ping)(ping)(ping)柜(ju),在(zai)自(zi)動化(hua)設(she)備的(de)金(jin)屬(shu)外(wai)殼可靠接(jie)(jie)地(di)(di),屏(ping)(ping)(ping)(柜(ju))的(de)門等活動部分與屏(ping)(ping)(ping)(柜(ju))體進行(xing)良(liang)好(hao)連(lian)接(jie)(jie)。采用(yong)上述幾種(zhong)措施后(hou),取得良(liang)好(hao)的(de)效果(guo),因(yin)雷(lei)擊造成(cheng)自(zi)動化(hua)設(she)備損(sun)壞的(de)故(gu)障率大(da)大(da)降(jiang)低。

  4、結束語

  雷電(dian)對自(zi)(zi)動化設備(bei)的(de)干(gan)擾,己(ji)嚴重(zhong)的(de)影響了(le)調度(du)(du)自(zi)(zi)動化系(xi)統(tong)(tong)的(de)安全運行(xing)(xing),曾經(jing)產生了(le)一(yi)些嚴重(zhong)的(de)事故(gu),因而要對處于弱電(dian)的(de)自(zi)(zi)動化系(xi)統(tong)(tong)的(de)防雷給于高度(du)(du)的(de)重(zhong)視,搞清雷電(dian)的(de)“來龍(long)去脈”,然(ran)后(hou)采取切實可(ke)行(xing)(xing)的(de)防范的(de)措(cuo)施,將雷害事故(gu)和干(gan)擾減少到(dao)最低程度(du)(du),從(cong)而為自(zi)(zi)動化設備(bei)可(ke)靠(kao)運行(xing)(xing)起(qi)到(dao)了(le)良好的(de)保障(zhang)作用(yong)。


來源:互聯網
采摘:godvsgay.com

如有(you)侵權(quan),請(qing)聯(lian)系刪(shan)除。


0755-2138 0067 留言咨詢
 

首頁 關于我們 產品中心 解決方案 工程實例 新聞中心 聯系我們 詢價單

Nav