一、WBTQSB-20KVA/50KV交流耐壓試驗變壓器概(gai)述
YDQ系列高壓試(shi)驗(yan)變(bian)壓器是根據《試(shi)驗(yan)變(bian)壓器》標(biao)準,在(zai)油(you)(you)浸式試(shi)驗(yan)變(bian)壓器的(de)基礎上而設計(ji)生(sheng)產的(de)。SF6氣(qi)體具有良好的(de)電(dian)氣(qi)絕(jue)緣(yuan)性能(neng)及優異(yi)的(de)滅弧性能(neng),其耐壓強度(du)為同一壓力下(xia)氮氣(qi)的(de)2.5倍(bei),擊(ji)穿(chuan)電(dian)壓的(de)空氣(qi)的(de)2.5倍(bei)。在(zai)0.25MPa下(xia)與油(you)(you)的(de)擊(ji)穿(chuan)電(dian)壓相等,在(zai)0.45MPa壓力下(xia)是油(you)(you)的(de)擊(ji)穿(chuan)電(dian)壓的(de)2倍(bei),是一種優于(yu)油(you)(you)的(de)新一代(dai)超高壓絕(jue)緣(yuan)介質材(cai)料(liao)。該(gai)產品技術(shu)要求完全(quan)符合(he)《ZBK-41006-89》標(biao)準,它是油(you)(you)浸式輕(qing)型(xing)試(shi)驗(yan)變(bian)壓器的(de)換代(dai)產品。該(gai)產品具有體積小、重量輕(qing)、不(bu)受氣(qi)候變(bian)化(hua)影(ying)響(xiang)、電(dian)暈小、現場(chang)搬運無需靜止(zhi)可使用(yong),使用(yong)壽命長、免(mian)維修(xiu)等特點。適用(yong)于(yu)電(dian)力系統、工礦企業、科研部門等對各種高壓電(dian)氣(qi)設備、電(dian)氣(qi)元件、絕(jue)緣(yuan)材(cai)料(liao)進行工頻或直(zhi)流高壓下(xia)的(de)絕(jue)緣(yuan)強度(du)試(shi)驗(yan)。
二、WBTQSB-20KVA/50KV交流耐壓試驗變壓器產品結構
YDQ系列高(gao)壓(ya)(ya)試驗(yan)變壓(ya)(ya)器采用單框芯式鐵芯結構(gou),初級繞(rao)(rao)組繞(rao)(rao)在(zai)鐵芯上(shang),高(gao)壓(ya)(ya)繞(rao)(rao)組在(zai)外,這種同軸布置減少了(le)漏磁(ci)通(tong),因而(er)增大了(le)繞(rao)(rao)組間(jian)的耦合(he)。產(chan)品(pin)的外殼為(wei)圓柱灌(guan)式容器結構(gou),能(neng)耐(nai)受0.8MPa以(yi)上(shang)壓(ya)(ya)力(li)。其結構(gou)見圖(tu)1:
三、WBTQSB-20KVA/50KV交流耐壓試驗變壓器工作原理
YDQ系列高(gao)(gao)壓試驗(yan)變(bian)(bian)壓器(qi)為單相變(bian)(bian)壓器(qi),聯結組標號(hao)Ⅰ.Ⅰ. 用(yong)(yong)工頻220V(10kVA以(yi)上(shang)為380V)電源接入 (為本(ben)公司生產的(de)(de)試驗(yan)變(bian)(bian)壓器(qi)配套專用(yong)(yong)設備(bei),詳細資料請見其具(ju)體使用(yong)(yong)說明書(shu))系列操作箱(xiang)(臺),經(jing)操作箱(xiang)內自偶調壓器(qi)(50kVA以(yi)上(shang)調壓器(qi)外附(fu))調節至0~200V(或0~400V)電壓輸出(chu)至YDQ試驗(yan)變(bian)(bian)壓器(qi)的(de)(de)初級(ji)繞組,根據電磁(ci)感(gan)應原理,在試驗(yan)變(bian)(bian)壓器(qi)高(gao)(gao)壓繞組可獲得(de)試驗(yan)所(suo)需的(de)(de)高(gao)(gao)電壓。
單臺YDQ系列高壓試驗變壓器(qi)的工作原理(li)圖(tu)見(jian)圖(tu)2。
單(dan)臺(tai)YDQ系列交(jiao)直流高(gao)(gao)壓(ya)試驗變(bian)壓(ya)器(qi)的工作原理圖(tu)(tu)見圖(tu)(tu)3,圖(tu)(tu)中高(gao)(gao)壓(ya)套管中裝(zhuang)有(you)高(gao)(gao)壓(ya)硅堆,串(chuan)接(jie)在高(gao)(gao)壓(ya)回路中作半波整(zheng)流,以獲得(de)直流高(gao)(gao)電壓(ya)。當用一短路桿將高(gao)(gao)壓(ya)硅堆短接(jie)時,可獲得(de)工頻高(gao)(gao)電壓(ya),作為交(jiao)流輸(shu)出狀態(tai);取消短路桿時,作為直流輸(shu)出狀態(tai)。
試(shi)驗變(bian)壓(ya)器高壓(ya)套管中的高壓(ya)硅堆未畫出,其原理(li)與(yu)上圖相同。
三(san)臺試(shi)(shi)(shi)驗(yan)(yan)(yan)變(bian)(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)串(chuan)級(ji)獲得更高電(dian)(dian)壓(ya)(ya)(ya)(ya)的(de)(de)(de)(de)接(jie)線(xian)原理(li)見(jian)圖(tu)4。串(chuan)級(ji)高壓(ya)(ya)(ya)(ya)試(shi)(shi)(shi)驗(yan)(yan)(yan)變(bian)(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)有(you)很大的(de)(de)(de)(de)優越性,因(yin)為(wei)整個試(shi)(shi)(shi)驗(yan)(yan)(yan)裝(zhuang)置(zhi)由幾臺單(dan)(dan)臺試(shi)(shi)(shi)驗(yan)(yan)(yan)變(bian)(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)組(zu)(zu)成,單(dan)(dan)臺試(shi)(shi)(shi)驗(yan)(yan)(yan)變(bian)(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)容(rong)量(liang)小、電(dian)(dian)壓(ya)(ya)(ya)(ya)低、重量(liang)輕,便(bian)于(yu)運(yun)輸(shu)和(he)安(an)裝(zhuang)。它既然可串(chuan)接(jie)成高出(chu)幾倍的(de)(de)(de)(de)單(dan)(dan)臺試(shi)(shi)(shi)驗(yan)(yan)(yan)變(bian)(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)輸(shu)出(chu)電(dian)(dian)壓(ya)(ya)(ya)(ya)組(zu)(zu)合使(shi)用,又可分開成幾套單(dan)(dan)臺試(shi)(shi)(shi)驗(yan)(yan)(yan)變(bian)(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)單(dan)(dan)獨使(shi)用。整套裝(zhuang)置(zhi)投資小,經濟實惠。圖(tu)5中,在(zai)**級(ji)和(he)**級(ji)的(de)(de)(de)(de)每個單(dan)(dan)元試(shi)(shi)(shi)驗(yan)(yan)(yan)變(bian)(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)中都有(you)一個勵磁繞(rao)組(zu)(zu)A1、C1和(he)A2、C2。在(zai)三(san)臺串(chuan)級(ji)試(shi)(shi)(shi)驗(yan)(yan)(yan)變(bian)(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)基本原理(li)中,低壓(ya)(ya)(ya)(ya)電(dian)(dian)源加(jia)在(zai)試(shi)(shi)(shi)驗(yan)(yan)(yan)變(bian)(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)Ⅰ的(de)(de)(de)(de)初(chu)級(ji)繞(rao)組(zu)(zu)a1x1上,單(dan)(dan)臺試(shi)(shi)(shi)驗(yan)(yan)(yan)變(bian)(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)Ⅰ、Ⅱ、Ⅲ的(de)(de)(de)(de)輸(shu)出(chu)電(dian)(dian)壓(ya)(ya)(ya)(ya)都是(shi)V。勵磁繞(rao)組(zu)(zu)A1、C1給(gei)**級(ji)試(shi)(shi)(shi)驗(yan)(yan)(yan)變(bian)(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)Ⅱ的(de)(de)(de)(de)初(chu)級(ji)繞(rao)組(zu)(zu)供電(dian)(dian);**級(ji)試(shi)(shi)(shi)驗(yan)(yan)(yan)變(bian)(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)Ⅱ的(de)(de)(de)(de)勵磁繞(rao)組(zu)(zu)A2、C2給(gei)第三(san)級(ji)試(shi)(shi)(shi)驗(yan)(yan)(yan)變(bian)(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)Ⅲ的(de)(de)(de)(de)初(chu)級(ji)繞(rao)組(zu)(zu)供電(dian)(dian)。**級(ji)試(shi)(shi)(shi)驗(yan)(yan)(yan)變(bian)(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)Ⅱ和(he)第三(san)級(ji)試(shi)(shi)(shi)驗(yan)(yan)(yan)變(bian)(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)Ⅲ的(de)(de)(de)(de)箱(xiang)體(ti)分別(bie)處在(zai)對(dui)地為(wei)1V和(he)2V的(de)(de)(de)(de)高電(dian)(dian)位上,所以箱(xiang)體(ti)對(dui)地是(shi)絕(jue)緣的(de)(de)(de)(de),試(shi)(shi)(shi)驗(yan)(yan)(yan)變(bian)(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)Ⅰ的(de)(de)(de)(de)箱(xiang)體(ti)是(shi)接(jie)地的(de)(de)(de)(de)。這樣**級(ji)、**級(ji)、第三(san)級(ji)試(shi)(shi)(shi)驗(yan)(yan)(yan)變(bian)(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)(qi)(qi)對(dui)地的(de)(de)(de)(de)額定(ding)輸(shu)出(chu)電(dian)(dian)壓(ya)(ya)(ya)(ya)分別(bie)為(wei)1V、2V、3V;其額定(ding)容(rong)量(liang)分別(bie)為(wei)3P、2P、1P。
YDQ系列高壓試驗變壓器做被試品的工(gong)頻耐壓試驗使(shi)用接線原理圖見圖5。
圖中:R1—限流(liu)電阻 FRC—阻容(rong)分(fen)壓器 RF—球間(jian)隙保(bao)護電阻 G—球間(jian)隙 CX—被試品(pin)
注:高壓(ya)尾必(bi)須(xu)可靠接(jie)地(di)
工頻耐壓(ya)(ya)試(shi)驗(yan)中限流電(dian)阻R1應(ying)根據試(shi)驗(yan)變壓(ya)(ya)器的(de)(de)額(e)定(ding)容(rong)量(liang)來選擇(ze)。如高壓(ya)(ya)側額(e)定(ding)輸(shu)出電(dian)流在100~300mA時(shi),可取0.5~1Ω/V(試(shi)驗(yan)電(dian)壓(ya)(ya));高壓(ya)(ya)側額(e)定(ding)輸(shu)出電(dian)流為1A以上時(shi),可取1Ω/V(試(shi)驗(yan)電(dian)壓(ya)(ya))。常用(yong)水電(dian)阻作為限流電(dian)阻,管(guan)子長度(du)可按150kV/m考慮,管(guan)子粗細應(ying)具有足夠(gou)的(de)(de)熱容(rong)量(liang)(水阻液配制方法:用(yong)蒸(zheng)餾(liu)水加(jia)入適量(liang)硫(liu)酸銅(tong)配制成各種(zhong)不同的(de)(de)阻值)。
球間隙(xi)(xi)及保護(hu)電(dian)(dian)阻:當電(dian)(dian)壓超(chao)過球間隙(xi)(xi)整定值時(一般取(qu)試驗(yan)電(dian)(dian)壓的110%~120%),球間隙(xi)(xi)放電(dian)(dian),對被試品(pin)起到(dao)保護(hu)作(zuo)用。球間隙(xi)(xi)保護(hu)電(dian)(dian)阻可按1Ω/V(試驗(yan)電(dian)(dian)壓)選取(qu)。
在(zai)工(gong)頻(pin)耐壓(ya)(ya)(ya)(ya)試(shi)驗(yan)(yan)(yan)(yan)中,低電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)側(ce)(ce)測量電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(儀表電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya))不是非常準(zhun)(zhun)確(que)的,其原因是由于試(shi)驗(yan)(yan)(yan)(yan)變(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)存在(zai)著漏抗,在(zai)這個(ge)漏抗上(shang)必(bi)然存在(zai)著壓(ya)(ya)(ya)(ya)降(jiang)或容(rong)升,使試(shi)品(pin)上(shang)的電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)低于或高(gao)于低壓(ya)(ya)(ya)(ya)側(ce)(ce)測量電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)表上(shang)反映(ying)出來的電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)。工(gong)頻(pin)耐壓(ya)(ya)(ya)(ya)試(shi)驗(yan)(yan)(yan)(yan)時,被試(shi)品(pin)上(shang)的電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)高(gao)于試(shi)驗(yan)(yan)(yan)(yan)變(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)的輸出電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya),也就是所謂容(rong)升現象。感(gan)應(ying)耐壓(ya)(ya)(ya)(ya)試(shi)驗(yan)(yan)(yan)(yan)時,試(shi)驗(yan)(yan)(yan)(yan)變(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)的漏抗必(bi)然存在(zai)著壓(ya)(ya)(ya)(ya)降(jiang)。為了準(zhun)(zhun)確(que)測量被試(shi)品(pin)上(shang)所施(shi)加的電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya),因此(ci)常在(zai)高(gao)壓(ya)(ya)(ya)(ya)側(ce)(ce)接入FRC阻容(rong)分壓(ya)(ya)(ya)(ya)器(qi)來測量電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(見圖5)。
工頻耐壓(ya)試驗(yan)操作(zuo)注意事項(xiang)
1)試驗人員應做好(hao)分(fen)工,明確相(xiang)互間聯系方法。并有專門人監護現場**及觀(guan)察試品狀(zhuang)態。
2)被(bei)試品(pin)應先(xian)清(qing)掃干凈,并**干燥,以免損壞(huai)被(bei)試品(pin)和試驗帶來的誤差。
3)對(dui)于大型試驗(yan),一般都(dou)應先(xian)進行空升試驗(yan)。即不接試品時(shi)升壓至試驗(yan)電壓,校對(dui)各種表(biao)計,調整(zheng)球(qiu)間隙。
4)升(sheng)壓(ya)速度(du)不(bu)能太(tai)快,并必須(xu)防止(zhi)突然加(jia)壓(ya)。例如調(diao)壓(ya)器不(bu)在零(ling)位(wei)時突然合(he)閘(zha)。也不(bu)能突然切斷(duan)電源,一般應在調(diao)壓(ya)器降至(zhi)零(ling)位(wei)時拉閘(zha)。
5)當(dang)電(dian)壓(ya)升(sheng)至試驗電(dian)壓(ya)時(shi),開始計時(shi),到(dao)1min后,迅速降壓(ya)到(dao)1/3試驗電(dian)壓(ya)以下時(shi),才能(neng)拉開電(dian)源。
6)在升(sheng)壓(ya)(ya)或耐(nai)壓(ya)(ya)試驗(yan)過(guo)程中(zhong),如發(fa)現下列不正常情況時,應立即降壓(ya)(ya),切斷電源。停(ting)止(zhi)試驗(yan)并查明原因(yin):①電壓(ya)(ya)表指針擺動(dong)很大;②發(fa)現絕(jue)緣(yuan)燒焦或冒煙(yan);③被試品內有(you)不正常的聲音。
7)耐壓試驗(yan)前后應測量絕緣(yuan)(yuan)電(dian)阻,檢查絕緣(yuan)(yuan)情況。
試(shi)驗(yan)變壓器在做被試(shi)品(pin)的(de)直流(liu)耐壓或(huo)泄露試(shi)驗(yan)時接線(xian)原理圖如圖6。
注:此試驗應(ying)先抽出短路桿“D”,圖(tu)6中所(suo)示。
圖中(zhong):VD—高壓(ya)(ya)硅堆 R1—限流電(dian)阻 C1—高壓(ya)(ya)濾波(bo)電(dian)容 FRC—阻容分壓(ya)(ya)器(qi) CX—被試品 μA—帶(dai)保護微安表
泄露試驗中限流電(dian)(dian)(dian)阻(zu)R1選擇(ze)在額定輸(shu)出電(dian)(dian)(dian)壓(ya)(ya)時,輸(shu)出端短路(lu)電(dian)(dian)(dian)流不超過(guo)高壓(ya)(ya)硅堆的(de)*大整(zheng)流。如電(dian)(dian)(dian)壓(ya)(ya)硅堆的(de)*大整(zheng)流電(dian)(dian)(dian)流為100mA時用于(yu)60kV的(de)試驗裝(zhuang)置中,限流電(dian)(dian)(dian)阻(zu)按R1=60/0.1=600kΩ選擇(ze)。限流電(dian)(dian)(dian)阻(zu)還應具有足夠的(de)容(rong)量和沿面(mian)放電(dian)(dian)(dian)距(ju)離(li)。
高壓濾波電容C1一般選擇(ze)在0.01~0.1μF,當被試品的電容量(liang)很大時,C1可省(sheng)略不用(yong)。
泄(xie)露試驗的操作及注意(yi)事(shi)項
1)試(shi)驗(yan)前應先檢查被試(shi)品是否(fou)停電(dian),接地放電(dian),一切對(dui)外連線是否(fou)擦干(gan)凈。要嚴防將(jiang)試(shi)驗(yan)電(dian)壓加到有人(ren)工作的(de)部位上(shang)去。
2)接(jie)好試驗裝置的接(jie)線后(hou),應復查(cha)無(wu)誤后(hou)才可加(jia)壓(ya)。應特別注意檢查(cha)高壓(ya)設備及引線與地、與操作人員的**距離(li),被(bei)試品的外殼(ke)是否可靠接(jie)地,要按**規(gui)程(cheng)中所(suo)規(gui)定的內容進行試驗。
3)對(dui)于(yu)大(da)電容量(liang)設備(bei)應(ying)緩慢升壓,防止被試品(pin)的充電電流燒壞微安表。必要(yao)時應(ying)分(fen)級加壓,分(fen)別讀取各(ge)級電壓下微安表的穩定讀數。
4)試(shi)驗(yan)過(guo)程中,應密切監視被試(shi)品、試(shi)驗(yan)裝(zhuang)置、微安表(biao),一旦發生擊(ji)穿(chuan)、閃爍等異常現象應立即(ji)降(jiang)壓,切斷(duan)電(dian)源,并查(cha)明原因,詳細記錄。
5)試驗完畢,降壓,切斷電源(yuan)后應將(jiang)被試品及試驗裝置本身充分(fen)放電。
四、WBTQSB-20KVA/50KV交流耐壓試驗變壓器注意事項
1、按照您所進行的(de)試驗(yan)(yan)接好工作線路(lu)。試驗(yan)(yan)變(bian)壓(ya)(ya)(ya)器的(de)外殼(ke)以及操作系統(tong)的(de)外殼(ke)必須可靠(kao)接地(di)。試驗(yan)(yan)變(bian)壓(ya)(ya)(ya)器高壓(ya)(ya)(ya)繞組的(de)X端(高壓(ya)(ya)(ya)尾)以及測量繞組的(de)F端必須可靠(kao)接地(di)。
2、做串級(ji)試(shi)(shi)驗(yan)時,**級(ji)、第三(san)級(ji)試(shi)(shi)驗(yan)變壓器的低壓繞組的X端(duan),測量(liang)繞組的F端(duan)以及高(gao)壓繞組的X端(duan)(高(gao)壓尾)均接本(ben)級(ji)試(shi)(shi)驗(yan)變壓器的外殼(ke)。**級(ji)、第三(san)級(ji)試(shi)(shi)驗(yan)變壓器的外殼(ke)必須(xu)通過絕緣(yuan)支架接地。
3、接通(tong)(tong)電(dian)源前,操作系統的調(diao)壓(ya)器(qi)必須(xu)調(diao)到零位后(hou)方可接通(tong)(tong)電(dian)源,合閘,開(kai)始(shi)升壓(ya)。
4、從(cong)零開始均(jun)勻旋轉(zhuan)調壓(ya)(ya)器手輪升(sheng)(sheng)(sheng)壓(ya)(ya)。升(sheng)(sheng)(sheng)壓(ya)(ya)方法(fa)(fa)(fa)有:快速(su)升(sheng)(sheng)(sheng)壓(ya)(ya)法(fa)(fa)(fa),即(ji)20s逐級升(sheng)(sheng)(sheng)壓(ya)(ya)法(fa)(fa)(fa);慢速(su)升(sheng)(sheng)(sheng)壓(ya)(ya)法(fa)(fa)(fa),即(ji)60s逐級升(sheng)(sheng)(sheng)壓(ya)(ya)法(fa)(fa)(fa);極(ji)慢速(su)升(sheng)(sheng)(sheng)壓(ya)(ya)法(fa)(fa)(fa)供選用。電(dian)壓(ya)(ya)從(cong)零開始按一定(ding)(ding)的(de)(de)升(sheng)(sheng)(sheng)壓(ya)(ya)方式(shi)和速(su)度上升(sheng)(sheng)(sheng)到您(nin)所需的(de)(de)額(e)定(ding)(ding)試(shi)(shi)驗電(dian)壓(ya)(ya)的(de)(de)75%后,在以(yi)每秒2%額(e)定(ding)(ding)試(shi)(shi)驗電(dian)壓(ya)(ya)的(de)(de)速(su)度升(sheng)(sheng)(sheng)到您(nin)所需的(de)(de)額(e)定(ding)(ding)電(dian)壓(ya)(ya),并(bing)密(mi)切(qie)注意測(ce)量儀表的(de)(de)指(zhi)示以(yi)及被試(shi)(shi)品的(de)(de)情況(kuang)。升(sheng)(sheng)(sheng)壓(ya)(ya)過程中(zhong)或試(shi)(shi)驗過程中(zhong)如發現(xian)測(ce)量儀表的(de)(de)指(zhi)示及被試(shi)(shi)品情況(kuang)異常,應(ying)立即(ji)降壓(ya)(ya),切(qie)斷電(dian)源(yuan),查明情況(kuang)。
5、試驗完(wan)畢后(hou),應在(zai)數秒(miao)內勻速的(de)將調壓器返回至零位,然(ran)后(hou)切(qie)斷電源(yuan)。
6、本產(chan)品不得(de)超過額定參(can)數使(shi)用。除試驗必須(xu)外(wai),決(jue)不允許(xu)全電(dian)(dian)壓(ya)通電(dian)(dian)或斷(duan)電(dian)(dian)。
7、再升壓或耐壓試驗(yan)過程中(zhong),如(ru)發現(xian)以下不正常情況時,應立即降壓,切斷(duan)電(dian)源,停止試驗(yan)并查明原因。
⑴電壓表指針擺動(或數字跳動)很大
⑵電(dian)流表直線(xian)上升
被(bei)試品內(nei)有不正常的(de)聲音
8、圖1中(zhong)第9項系壓(ya)力(li)閥及壓(ya)力(li)表,為(wei)長期關(guan)閉狀態。每(mei)6個月開閥一次(ci),以檢查SF6壓(ya)力(li),應不小于0.2MPa(檢查壓(ya)力(li)后立即關(guan)閉閥門(men)),低于0.2MPa時應加SF6氣體,以增加氣絕緣。
9、耐(nai)壓實驗前后應測量(liang)被(bei)試設備的絕(jue)緣(yuan)電阻,檢查絕(jue)緣(yuan)情況(kuang)。
10、當試(shi)驗變壓(ya)器長(chang)期不(bu)使用時,應放置于(yu)通風(feng)、干燥、無陽光直(zhi)射(she)的地方。
11、該產(chan)品(pin)不(bu)允許在高于45℃的溫度下長期存(cun)放、使用、放氣。
12、運(yun)輸搬運(yun)途中(zhong)不得重力沖擊。
13、產品(pin)緊固件及壓力閥(fa)、壓力表不得擅自松動。
14、使用本產(chan)品做高壓(ya)試驗(yan)(yan)時(shi),出(chu)熟悉本說明(ming)書外(wai),還(huan)必(bi)須嚴(yan)格執行國家有關標準(zhun)和操(cao)作規(gui)程(cheng)。可參照GB311-83《高壓(ya)輸變(bian)設(she)備(bei)的絕緣配合,高壓(ya)試驗(yan)(yan)技術》;《電(dian)氣設(she)備(bei)預(yu)防(fang)性試驗(yan)(yan)規(gui)程(cheng)》等。
五、WBTQSB-20KVA/50KV交流耐壓試驗變壓器容量選擇
標稱試驗變(bian)壓器容量Pn的確(que)定公式:Pn=kVn 2ωCt×10-9
式(shi)中:
Pn——標稱試驗變壓器容量(kVA)
Vn——試驗(yan)變壓(ya)器的額定輸(shu)出高(gao)壓(ya)的有(you)效值(kV)
k ——**系數。k≥1,標稱(cheng)電(dian)壓(ya)Vn≥1MV時,k=2;標稱(cheng)電(dian)壓(ya)較低時,k值(zhi)可取高一些。
Ct——被試品的(de)電(dian)容量(liang)(pF)
ω——角頻率(lv),ω=2πf, f——試驗(yan)電源的頻率(lv)
被試設備(bei)的電(dian)(dian)容量Ct可由交流電(dian)(dian)橋(qiao)測出。Ct的變(bian)化很大,
可(ke)由設備的(de)類(lei)型而定。
典型數據如(ru)下:
簡單的棒式(shi)或懸式(shi)絕緣子(zi) 幾十微法
簡單的分級套(tao)管 100~1000pF
電壓互感器 200 ~ 500pF
電力變(bian)壓器 < 1000kVA ~1000pF
> 1000kVA 1000~10000pF
高壓(ya)電力電纜和油浸(jin)紙絕緣 250~300pF/m
氣體絕(jue)緣 ~60pF/m
封閉變電站,SF6氣(qi)體絕緣 100~10000Pf;
對于不(bu)(bu)同(tong)的試驗電壓(ya)Vn,選擇(ze)不(bu)(bu)同(tong)的(適當的)**系數k。
以(yi)下(xia)列出不同(tong)的Vn所選用的k值供(gong)參(can)考。
Vn =50~100kV k = 4
Vn =150~300kV k = 3
Vn > 300kV k = 2