描述
(2)tgδ與溫度的關(guān)系。對于油紙絕緣的互感器。tgδ與溫度的關(guān)系取決于油紙的綜合性能,良好的絕緣油是非極性物質(zhì),油的tgδ主要是導(dǎo)電損耗,隨溫度的升高指數(shù)上升,紙是極性介質(zhì),其tgδ隨偶極子的松弛而損耗減小,故紙的tgδ在-40~60℃的范圍內(nèi)隨溫度增加而減小,因此在此溫度范圍內(nèi)油紙絕緣的tgδ應(yīng)無變化,不必進(jìn)行溫度換算,當(dāng)溫度上升到60~70℃及以上時,電導(dǎo)損耗的增長占主導(dǎo)地位,tgδ便隨溫度的升高而增大,此時就需進(jìn)行溫度換算,而不宜簡單采用充油式設(shè)備的換算方式。
當(dāng)油紙中殘存有較多水分與雜質(zhì)時,tgδ與溫度的關(guān)系就不同于上述情況,此時介質(zhì)損耗以離子電導(dǎo)損耗占主導(dǎo)地位,tgδ隨溫度的升高而明顯增大。如兩臺LCLWD3-220型電流互感器,接通50%的電流5h,比較通電前后tgδ的變化情況為:tgδ初始值為0.53%的一臺無變化,tgδ為0.18%的一臺則上升為1.1%。這說明初始值為0.18%的電流互感器絕緣已有缺陷,故其tgδ隨溫度的升高而增大。因此當(dāng)常溫下測得的tgδ值較大時,就應(yīng)該考察其較高溫度下tgδ的變化情況,若在較高溫度下tgδ有明顯增加,則其絕緣存在缺陷。
(3)tgδ與電壓的關(guān)系。良好絕緣的互感器,其tgδ隨電壓升高應(yīng)無明顯變化,如果有變化則說明絕緣存在缺陷。因此在預(yù)試規(guī)程中規(guī)定了試驗(yàn)電壓由10kV升到Um/1.732時,如果tgδ的增減量超過±3%,則該互感器就不宜繼續(xù)運(yùn)行。
(4)測量電壓互感器絕緣支架tgδ的重要性.串級式電壓互感器的鐵芯具有一定的電位,由絕緣支架承受,一旦絕緣支架在生產(chǎn)壓制過程中工藝把關(guān)不嚴(yán),在運(yùn)行中就有可能發(fā)生事故。近幾年來的運(yùn)行情況表明:絕緣支架的tgδ大于10%的互感器,解體后其絕緣支架均有缺陷,受潮嚴(yán)重的甚至可以捏出水;有的情況稍好,但中間也已分層,并可觀察到有放電痕跡;受潮較輕的絕緣支架表面有麻點(diǎn)狀變色,螺孔有放電痕跡。
串級式電壓互感器的密封不良則易進(jìn)水受潮,使得絕緣強(qiáng)度明顯下降,繼續(xù)運(yùn)行則可能引發(fā)層匝間和主絕緣擊穿故障;如固定鐵芯的絕緣支架材質(zhì)不好,分層開裂內(nèi)部形成氣泡,則在運(yùn)行電壓的作用下氣泡發(fā)生局部放電,進(jìn)而整個絕緣支架閃絡(luò)。在實(shí)際工作中采用末端屏蔽法測量絕緣支架的tgδ時,此時一端及底座接地,如果小瓷套或二次接線板受潮臟污時產(chǎn)生的測量誤差被屏蔽,則一次靜電屏對二次和輔助二次繞組及絕緣支架的tgδ均檢測不到,但可測量到下鐵芯柱上一次繞組對二次和輔助二次繞組的tgδ,若該處的tgδ值大于2.5%則應(yīng)查明原因,若其值大于4%且增量較大時,則可以斷定該互感器必有缺陷。
產(chǎn)品廣泛應(yīng)用于:電力、石油、礦井提升、港口、供熱、燃?xì)狻⒐┧?、污水處理、冶金、造紙、紡織、化工、水利等現(xiàn)代化工業(yè)領(lǐng)域!
我們這里有您急需的停產(chǎn)備件,
優(yōu)勢現(xiàn)貨,詢不到的,買不到的,請聯(lián)系我們!
絕 對優(yōu)勢,絕 對低價!絕 對正品,優(yōu)質(zhì)的產(chǎn)品,一流的服務(wù),充足的庫存,
歡迎來電詢價,我們將會給您最優(yōu)惠的價格!
主營:世界知名品牌的PLC、DCS系統(tǒng)備件模塊
①Allen-Bradley(美國AB)系列產(chǎn)品》
②Schneider(施耐德電氣)系列產(chǎn)品》
③General electric(通用電氣)系列產(chǎn)品》
④Westinghouse(美國西屋)系列產(chǎn)品》
⑤SIEMENS(西門子系列產(chǎn)品)》
⑥銷售ABB Robots.FANUC Robots、YASKAWA Robots、KUKA Robots、Mitsubishi Robots、OTC Robots、PanasonicRobots、MOTOMAN Robots。
⑦estinghouse(西屋):OVATION系統(tǒng)、WDPF系統(tǒng)、MAX1000系統(tǒng)備件。
⑧Invensys Foxboro(??怂共_):I/A Series系統(tǒng),F(xiàn)BM(現(xiàn)場輸入/輸出模塊)
順序控制、梯形邏輯控制、事故追憶處理、數(shù)模轉(zhuǎn)換、輸入/輸出信號處理、數(shù)
據(jù)通信及處理等。Invensys Triconex:冗余容錯控制系統(tǒng)、基于三重模件冗余(TMR)
結(jié)構(gòu)的zui現(xiàn)代化的容錯控制器。
⑨Siemens(西門子):Siemens MOORE,Siemens Simatic C1,Siemens數(shù)控系統(tǒng)等。
⑩Bosch Rexroth(博世力士樂):Indramat,I/O模塊,PLC控制器,驅(qū)動模塊等。
◆Motorola(摩托羅拉):MVME 162、MVME 167、MVME1772、MVME177等系列。
ABB 3HAB 6182-1 DSQC335 Robot Computer
ABB 3HAB8101-3/05D DSQC345B DriveUnit
ABB 3HAB8101-3/08C DSQC345C DriveUnit
ABB 3HAB8101-7/01C DSQC346C DriveUnit
ABB 3HAB8101-8 DSQC346G DriveUnit
ABB cable DSQC351 Interbus-S
ABB 3HAC 0373-1 DSQC361 Main Computer
ABB 3HAC3180-1 DSQC373 Robot Computer
ABB 900054 1Gb SD-card S3/S4 DDR
ABB 900056 1Gb SD-card S2 DDR
3HNE 00026 Teach Pendant
3HNE 00312-1 Teach Pendant
3HNE 00313 Teach Pendant
CHAA 3560-AXA Teach Pendant
ABB 3HAB9271-1/01B DriveUnit Dummy DriveUnit Dummy
ABB 57510001-AA DSCA 114 Print out board
ABB 57520001-U DSCA 121 Communication board
ABB 57160001-A DSDI 110 Digital input board
ABB 57160001-K DSDO 110 Digital output board
ABB YB161102-AH DSDX 110 Digital in/output board
ABB 57160001-TP DSDX B001 digital in-output board
ABB 57360001-U DSMB 124 Semiconductor memory board
ABB 57360001-AN DSMB 125 Semiconductor memory board
ABB 57360001-HG DSMB 127 Memory board
ABB 57330001-N DSMC 110 Floppy disk controller
ABB YB161102-AK DSPA 110 Axis computer
ABB 57310256-AF DSPC 150 Central processor
ABB 57310256-BA DSPC 153 Expand.single board computer
ABB 57310001-GP DSPC 157 Expand.single board computer
ABB YB161102-AD DSQC 103 Resolver power board
ABB YB161102-AF DSQC 105 Display board
ABB YB161102-BA DSQC 110 Programming board
ABB YB161102-BS DSQC 115 Resolver power board+2 analogue
ABB YB161102-BE DSQC 116 Power supply
ABB YB161102-BG DSQC 117 Resolver power board
ABB YB161102-BU DSQC 124 Terminal unit
ABB YB161102-BV DSQC 129 R/D board
ABB YB161102-CH DSQC 136 Safety board
ABB YB161102-CM DSQC 138 Terminal unit
ABB YB560103-AC DSQC 202 Robot computer
ABB YB560103-AS DSQC 208A External axis board
ABB YB560103-AL DSQC 209 Analogue I/O board
ABB YB560103-AM DSQC 210 Safety board
ABB YB560103-AN DSQC 211 Power supply
ABB YB560103-BF DSQC 215 Robot computer
ABB YB560103-AZ DSQC 220 Programming board
ABB YB560103-BD DSQC 223 PC Board digital I/O
ABB YB560103-BE DSQC 224 PC Board combi I/O
ABB YB560103-BK DSQC 227 Winchester interface
ABB YB560103-BD DSQC 228 Safety board
ABB YB560103-BN DSQC 230 Robot computer
ABB YB560103-BS DSQC 233 External axis board
ABB YB560103-BY DSQC 235A Rectifier
ABB YB560103-BZ DSQC 235B Rectifier
ABB YB560103-CA DSQC 236A Drive unit
DSQC 236B Drive
ABB YB560103-CC DSQC 236C Drive unit
ABB 3HAB2207-1 DSQC 236D Drive unit
ABB YB560103-CD DSQC 236G Drive unit
ABB 3HAB2245-1 DSQC 236H Drive unit
ABB 3HAA3563-AJA DSQC 236P Drive unit
ABB YB560103-CE DSQC 236T Drive unit
DSQC 239 Board-ABB RIO
ABB DSQC 241 Power supply
ABB YB560103-CM DSQC 242 Programming board
ABB 3HAA0001-CP DSQC 243 Serial measurement board
ABB 3HAA3563-ACA DSQC 245 Serial measurement board
ABB 3HAA3563-AAA DSQC 248 Programming board
ABB 3HAA3563-AGA DSQC 249A Rectifier
ABB 3HAA3563-AHA DSQC 249B Rectifier
ABB 3HAA3563-AD DSQC 252 System board
E3HAC028756-001 DSQC 253 SMB unit DSQC 573
E3HAA3563-AMA DSQC 253 Serial Measurement Board
E3E 042816 DSQC 253 Exch.Serial mes.DSQC 253W
6369901-218 DSQC 253 Serial Measurement Board
ABB 3HAB2211-1 DSQC 256A System board
ABB 3HAA3563-AUA DSQC 258 Power supply
ABB 3HAB8797-1 DSQC 266B Drive unit
ABB 3HAB8798-1 DSQC 266C Drive unit
ABB 3HAB8801-1 DSQC 266G Drive unit
ABB 3HAB8800-1 DSQC 266H Drive unit
ABB 3HAB8799-1 DSQC 266K Drive unit
ABB 3HAB8802-1 DSQC 266T Drive unit
ABB 3HAA3573-AAA DSQC 300 Board-Computer
ABB 3HAB2210-1 DSQC 300 Board-Computer














銷售熱線:18150087953