B quyt hn ch thm ha trm bin p16/04/2013 15:24:05Bng cch bo tr ng cch cc cu dao v mi ni, cc k thut vin c th ngn nga c nhiu trng hp s c v ct in tn km, mt nhiu thi gian x l.

Trong khi bn ang lm vic trong trm bin p, nhiu vn rc ri s len li vo trm m bn khng h hay bit, trong s c nhng trng hp c th dn ti thm ha. Nh cc chuyn gia ngnh in lc u bit, s c thm khc trm bin p c th gy nhiu tai ting - iu m bn khng h mong mun.ng tic l khng c th php mu no c th ngn nga s c trm bin p. Cc s c ny c th do nhiu yu t gy ra, v d nh my bin p in lc, acqui, my ct in hoc h thng bo v khng hot ng hoc chnh nh sai. Nhng mt trong s cc vn thng gp nht xoay quanh cc rc ri lin quan n cu dao v cc mi ni thanh ci.Cc rc ri loi ny c th ph hng trm bin p v gy thit hi ln. Ngoi ra, cng c th v chng m phi dng thc hin mt s k hoch chuyn mch bi v mt s cu dao khng th m ra c, hoc khng th ng li c, hoc te la khi phi mang ti hoc phng in h quang khi ct ti.Qut bng tia hng ngoiKhi nh gi tnh trng trm bin p ca cng ty in lc, cc cu dao v mi ni cn c a ln hng u danh sch cc hng mc. Ch cn c o to cht t l cc i th ca cng ty in lc c th thc hin bo dng cu dao. V mt khi cc cu dao v cc mi ni lm vic tt, mi nguy c ln dn n s c thm khc s c loi tr, mi thao tc ng ct trong tng lai s thc hin c sun s v ng nh d nh.Qut bng tia hng ngoi gip k thut vin pht hin cc ch c vn . S rt c ch nu qut hng ngoi ton b cc trm bin p v mt s ng dy truyn ti mi nm mt ln. Ngoi ra, nu c th, tt nht l sp xp tin hnh qut hng ngoi vo nhng thi im ph ti ang cao. Khi qut hng ngoi, iu quan trng cn lu l tia hng ngoi l phng tin c lc nhng khng hon ho. C th, s l v ngha nu qut hng ngoi cc cu dao m bnh thng lun t v tr ct hoc qut cc cu dao cp in cho cc ph ti khng hot ng trong ngy qut. Dy in vn c th chy ri cho d dy c qut hng ngoi, thm ch ngay c khi dy mang ti trong lc ang qut.Nu thy c mi ni hng ch mt thi gian ngn sau khi qut hng ngoi, cng ty in lc cng nn lng ti kh nng mi ni b s c theo chu k. Trong trng hp ny, mi ni c th nng ln khi mang ti ti mc chy ra v sau hn dnh vo nhau. Mi hn ny to thnh mi ni tt, t nht l i vi dng in vo thi im , v khi qut hng ngoi mi hn dnh ny c th khng thy c vn g. Nhng sau ny, khi dng in tng ln, vt qu kh nng mang dng ca ch hn dnh, dy dn s chy t lm i.

Nhiu vn rc ri len li vo trm m bn khng h hay bitChun b ngn chn thnh cng cc trng hp mt in khng ng lc, k thut vin trm bin p khng nn tin hon ton vo cng ngh hng ngoi. Thay vo , h cng nn tnh n vic b sung thm cc php o in tr trong trm bin p.Vic kim tra ny cng c th p dng cho cc cu dao trn li truyn ti v phn phi, hoc mt s mi ni ng dy chn. kim tra in tr cn c micromt l loi thit b o nhng in tr rt nh (v d in tr ca on thanh ci di c mt mt).Sau khi thc hin php kim tra ny i vi tt c cc cu dao v cc mi ni trong trm bin p, ngi kim tra c th an tm chc chn rng cc hng mc t yu cu kim tra s khng nng ln ph ti danh nh v tt c cc cu dao u c kim tra, thm ch c cc cu dao m bnh thng lun trng thi m.Trc tin bn cn c mt s dng c c bn v linh kin bo tr cn thit cho vic kim tra. u tin, v quan trng nht, bn cn mt micrommt tt, v d nh chic micrommt DLRO200-115 do cng ty Megger Group Limited (bang Texas, M) ch to.y l loi thit b to ra c dng in mt chiu 200 A lc. Li th ca dng in mt chiu lc l bn c th trnh c hin tng tc ng sai.Nu bn c mt s vi sai v cc rle vn c u ni vi my bin dng in (CT) ca thit b bn ang th nghim, bn c th cho dng in mt chiu lc chy qua my bin dng in (CT) v mch vi sai s khng cm nhn dng in mt chiu ny.Ngoi ra, bn cn c cc bu lng c nng cp dng cho cc tm kp mi ni v cc tm kp lng kim c ba kch c (hai l, bn l 3/7,62 cm, v 4 l 4/10,16 cm). L do s dng cc tm kp lng kim l v i khi cc mi ni b hng, m nguyn nhn l v ai lp khng ng cch, ng p vo nhm.iu ny c th sa li c bng cch t cc tm kp lng kim gia cc kim loi khng tng thch (v d nh ng v nhm). Nng cp h thng cc bu lng dng cho cc mi ni l tng tt. Thng thng, nu nh mi ni khng t th nghim in tr nh, ch cn thay bu lng l .H thng mi ni c a dng cho cc mi ni loi tm kp bt bu lng bao gm mt bu lng thp khng g ( di nh ra ngoi ai c ti thiu l hai bc ren), hai vng m phng bng thp khng g dy 3/16 (5 mm), mi chic t mi bn ca mi ni, mt vng m g (vng m Belleville) bng thp khng g, lc p danh nh l 3.500 pao (1.600 kg lc) t pha ai c v mt ai c bng ng thanh silic.Cc bu lng c ng knh ren 1/2 (12,7 mm) v cn c sit cht vi mmen 45 ft-lb (60 Nm). Mmen ny s nn vng m g Belleville c lc nn danh nh 3.500 pao mc khong 60 %, iu c ngha l mi ni c th dn ra co li theo chu k nng ln - ngui i v khng lm bin dng qu mc bu lng. V mi ni s duy tr cng khng i, nm ny qua nm khc.B quyt cui cng l lm sch cc b mt lp rp bng nc ra chn Scotch Brite hoc bt c cht ty ra no khc cn thit lm sch cc b mt ny. Sau , ph ln cc b mt ny lp chng oxy ha, v d nh DE-OX, mt loi cht c ch oxy ha thn thin vi mi trng, khng c mt (non-gritted) ca cng ty Ilsco (bang Ohio, M).Khng cn phi s dng cht chng oxy ha c mt bi v cc chi tit c ct in v c th lm sch c hon ton. Nu khng th ty sch cht chng oxy ha c kt li bng nc ra chn Scotch Brite, th hy th s dng dao co sn. V nguyn tc, trnh nh giy rp hoc gia bi v, nu cc u ni c trng thic, bn c th d dng lm mt i lp thic trng.

K thut vin kim tra thit b trm bng micrmtTh nghim thit bSau khi lm sch v chun b cc b mt, tin hnh kim tra bng micromt. K thut vin cn t kp o bao ton b khi lp rp cu dao, bao gm tt c cc mi ni lin quan vi cu dao.iu quan trng l phi lm sch thanh ci l ra phn kim loi ca mi ni bng cch dng bn chi kim loi v nh giy rp nh nhng. tnh ti c microm (, bng mt phn triu ca ) khng phi bt k gi tr in tr no cng t yu cu. Nhiu khi phi a dng in ln mc ti a 200 A mi o c chnh xc, vi iu kin tt cc b phn hp thnh u c thng s danh nh ph hp vi dng in ny.iu quan trng l t nht mt pha ca cu dao, hoc ca bt c b phn no bn ang kim tra, khng c ni t.Mt cch lm l o tr s ca ton b khi lp rp, v nu ch s ny t yu cu, th c ngha l bn hon thnh nhim v. Cc gi tr bn o c s khc nhau, ty theo cht lng v vt liu ca cu dao, nhng vi mt cu dao ng dng in danh nh 1.200 A (cng vi cc tm kp ca cu dao c hai u v thanh ci ti cc mi ni u ni c hai u) in tr o c c th vo c khong 350 .Bn s nhanh chng quen thuc vi gi tr d kin. Ci bn phi tm l nhng gi tr cao hn hn. Nu bn ang kim tra mt cu dao khc kiu v bn khng bit r kt qu o th no l thch hp, nu c ba cc ph hp vi nhau, rt c th l thit b bn o t yu cu v in tr. Nu c mt hoc hai cc c gi tr cao hn hn, bn c th phi x l cc cc c gi tr o ln hn xem c th a cc gi tr ny v ph hp vi cc cc c gi tr o nh hn.Nu bn gp cc c vn khi ang s dng cch u ni i qua tt c cc b phn, khi bn gi nguyn cc mi ni a dng in 200 A i qua ton b cu dao, trong khi di chuyn cc u dy in p qua tng mi ni ring l.V d, bn c th o in tr ca ng mt u ca cc tip im ca cu dao, cc tm kp bt bu lng, kp thanh ci hoc u khp bn l ca cu dao. Cch lm ny s cho php bn cch ly nhanh chng ch c vn tp trung ch . Tt c c thc hin bng cch di chuyn cc u d in p, cn ngun dng 200 A vn c u ni i qua ton b cu dao.Kim tra thit bVic di chuyn nh trn cc u d ca micromt qua tt c cc cu dao cn c thc hin kt hp vi vic bo tr cu dao. Cc tip im cn c lm sch, cn thn khng xc lp m bc trn mt cc tip im. Bn phi kim tra xem cc cc v cc tip im c thng hng hay khng, v c bit ch n tnh trng cc tip im xem c b r hoc lp ph bc c b hao mn hay khng.Kim tra m bo p lc tip im v sau bi lp m trng Dow Corning 1292 (bang Michigan, M). u im ca m ny l n s lun trng thi mm, v vy sau 3 - 5 nm, khi tr li bo tr thng k, bn ch cn dng gi lau l sch m ny.Nu l loi cu dao ph ti, iu quan trng l phi kim tra b phn ct dng. Cu dao ph ti lm vic bng cch ni mch song song gia cc tip im ca cu dao v b phn ct dng khi cu dao bt u m ra. Thng thng, a s cc nh sn xut cu dao khng mun c bt c dng in no chy qua b phn ct dng khi cu dao v tr ng. Nu ng l nh vy, th phi kim tra khe h thch hp, nu khng b phn ngt dng c th b chy trong khi ti mc bnh thng.Khi cu dao m ra, dng in ph ti c phn nhnh gia cc im tip im chnh v b phn ct dng. Vic phn nhnh song song ny phi c duy tr khi tip tc m cu dao cho n khi c khe h gia cc tip im chnh trnh phng in tr li khi ph ti b ct.Vic ct mch s xy ra bng cch s dng bung chn khng hoc b phn thi dp h quang. Trong c hai trng hp, bn u cn phi kim tra thy rng b phn ct dng v tr ng c in tr thp. Trong a s cc trng hp, c th s dng gi tr in tr bt k di 1 nh gi t/khng t.Sau khi chng minh c th a dng in qua b phn ct dng v tr ng, bc tip theo l chng minh b phn ct dng c th ct dng in in p ton phn. Nu b phn ct dng l loi thi dp h quang, bn khng c cch thc t no th nghim. Nu b phn ct dng l loi bung chn khng, cn xc nhn vi nh sn xut rng c th th nghim cao p bung chn khng. t in p ln bung chn khng v tr m mch l cch duy nht chng minh chn khng tn ti v b phn ct dng in s ct c dng in ph ti in p dy.Nu tun th tt c cc trnh t ny ti tt c cc mi ni v cc cu dao trong trm bin p theo chu k 3 n 5 nm mt ln, bn c th loi tr c t nht mt ngun gc nguy him lun rnh rp sn sng gy s c thm khc trong trm bin p.