016 nterntionl Conference on Power Engineering & Energy, Environment (PEEE 016) SBN: 978-1-60595-376- Power Trnsformer Decopling nd Simltion of Voltge nd Crrent of Winding nsltion Defect Chen Ling 1,, Shi Pxin,b, Tintng Xing 3,c, Ysheng Qn,d 1 Sichn Electric Power Reserch nstitte of Stte Grid Sichn Electric Power Compny, Chengd, 61007, Chin Beijing Key Lbortory of High Voltge & EC (North Chin Electric Power niversity), Beijing, 1006, Chin 3 Gng n Power Spply Compny of stte grid Sichn Electric Power Compny, Gng n, 638550, Chin cxxxz@163.com, b milkywydrem@16.com, c 778660047@qq.com, d qysh@vip.163.com Keywords: Power trnsformer, decople, simltion, winding deformtion, insltion defects Abstrct. n this pper decopling method is proposed ccording to the block of ech phse winding. According to the reltion, the crrent signls in ech set of prmeters cn be corresponding to single set of voltge signls. Simltion nlysis of trnsformer model is crried ot. The simltion reslts show tht there is difference between the voltge nd crrent in different winding sttes. t hs lid fondtion for the dignosis of trnsformer winding deformtion nd other insltion defects. ntrodction Power trnsformer is one of the key eqipments in power system, so its stbility nd relibility will ply very importnt role in the secrity of power system [1-3]. The power trnsformer genertes winding deformtion nder the ction of the electric power nd the mechnicl force becse of the short circit of the electric power trnsformer [4,5]. The winding deformtion inclde xil nd rdil size Chnge, body displcement, distortion, blging nd winding intertrn short circit etc. This is one of the mjor problems in the sfe opertion of power system [6]. Trnsformer winding decopling Electromgnetic copling exists mong the vrios windings of the power trnsformer, nd decopling is n effective method to nlyze the chrcteristics of the trnsformer windings. To the whole trnsformer winding, the reltionship of self indctnce nd mtl indctnce between different phses nd different voltge levels is shown in eqtion 1: n order to simplify the eqtion nd decople the eqtion, the B nd C phses re symmetricl to LA Am A AC Amc Ac A phse. ke the block mtrix: A ma Lm m B mc mmc mc, the reltionship A m L C mc c of cpcitnce between the vrios phses nd different voltge of the trnsformer winding is s follows eqtion :
A x m x LA Am A AB Amb Ab AC Amc Ac ia x ma Lm m mb mmb mb mc mmc mc i m B A m L B mb b C mc c i x BA Bm B LB Bm Bb BC Bmc Bc ib mb mba mbm mb mbb Lmb mbb mbc mbmc mbc i mb (1) x t ba bm b bb bmb Lb bc bmc bc ib b CA Cm C CB Cmb Cb LC Cmc Cc i C x mca mcm mc mcb mcmb mcb mcc Lmc mcc imc C x c cm c cb cmb cb cc cmc Lc ic mc x c x ia iak im i mk i i k ib ibk imb imbk t ib ibk ic i Ck imc imck ic ick () A m CA CAm CA CAB... CAc CAm CA CAB... CAc CmA Cm CmA... Cmc Cm...... C mc B CA Cm C CA... Cc...... C c mb.. t b.. C.. mc c n order to simplify the eqtion nd decople the eqtion, the B nd C phses re symmetricl to A phse. ke the block mtrix: CA CAm CA CAB... CAc CAm CA F CmA Cm CmA... Cmc C m CA Cm C CA... C c CAB... CAc G...... C mc...... C c. There is nother reltionship:
iak K A 0 0 A i mk 0 Km 0... m i k 0 0 K... t..... (3).... K A 0 0 ke the H 0 Km 0 0 0 K By the bove, tke ech block mtrix into the originl reltion cn be: A B B L B A B x (4) t B B A F G G K L G F G x (5) t G G F H 0 0 K 0 H 0 (6) t x 0 0 H 1 L1 K1 n which, L L, K K 3 L3 K3 n order to nlyze the winding of the trnsformer, it is necessry to decopling winding prmeter for nlysis, tke the Kren Ber trnsform: 1 1 1 1 1 1 1 1 S 1 1 S 1 1 0, 3 (7) 1 1 1 0 1 So we cn get reltionship of voltge nd crrent withot copling between different phse nd different voltge. A B 0 0 L 0 A B 0 x (8) t 0 0 A B F G 0 0 K L 0 F G 0 x (9) t 0 0 F G H 0 0 K 0 H 0 (10) t x 0 0 H The bove nlysis is considered the trnsformer s nondestrctive one, when consider the trnsformer loss dd mtrix R9 9. nder low freqency: A B B L R B A B x (11) t B B A
F G G G F G x (1) t G G F According to the bove nlysis, in order to decople different winding, tke the Kren Ber trnsform: A B 0 0 R L 0 A B 0 x (13) t 0 0 A B F G 0 0 0 F G 0 x (14) t 0 0 F G R S( A B) ( F G) 0 0 d 1 S 0 R 1 S ( A B ) ( F G ) 0 dx 0 0 R1 S( A B) ( F G) ( F G) R 1 S( A B) 0 0 d S 0 ( F G) R1 S( A B) 0 dx (16) 0 0 ( F G) R1 S( A B) Here, re the complex freqency domin to the fnction colmn vector. When not considering the resistnce, there re: d ( A B)( F G) 0 0 S 0 ( A B )( F G ) 0 dx (17) 0 0 ( A B)( F G) ( A B)( F G) 0 0 d S 0 ( A B)( F G) 0 dx (18) 0 0 ( A B)( F G) From the bove derivtion we cn get reltionship of voltge nd crrent of different phse does not exist the copled eqtions 1 F G 0 0 1 0 F G 0 x t 3 0 0 F G 3 1 H 0 0 1 0 H 0 t x 3 0 0 H 3 This pper simltes three-phse three winding trnsformer (0/110/10kV). Winding flt point is A phse winding deformtion. When the winding deformtion occrs, to reflect chnges in the prmeters in the simltion model is the eqivlent winding resistnce decreses nd rectnce increses. When the hrmonic exits rich, trnsformer flt cn be better extrcted, so we pt diode fter the sorce. Simltion voltge nd crrent wveform before nd fter the flt of phse A is shown in figre1-figre4: (15) (19)
Figre 1. A phse winding voltge wveform nder norml conditions. Figre. A phse voltge wveform nder the condition of winding deformtion. Figre 3. A phse winding crrent wveform nder norml conditions.
Figre 4. A phse crrent wveform nder the condition of winding deformtion. t cn be seen from the simltion tht the port voltge nd crrent wveform of the trnsformer fter the trnsformer winding deformtion re deformed. Both the mplitde nd the phse re chnged obviosly. De to the high freqency component from the diode, the chnge of the wveform becomes more obvios. By sing the voltge nd crrent wveform of the port nd the comprison expression. The position nd severity of the winding deformtion cn be obtined by the chrcteristic of the winding deformtion of the winding. Smmry n this pper, the electromgnetic copling reltionship between the low voltge winding of the high voltge winding of the trnsformer in different phses is nlyzed. A series of derivtion nd simltion re crried ot, nd the following conclsions cn be obtined. 1. A decopling method is proposed ccording to the block of ech phse winding. According to the reltion, the crrent signls in ech set of prmeters cn be corresponding to single set of voltge signls.. Simltion nlysis of trnsformer model is crried ot. The simltion reslts show tht there is difference between the voltge nd crrent in different winding sttes. t hs lid fondtion for the dignosis of trnsformer winding deformtion nd other insltion defects. References [1] Jin Hong,o Yeping,Wng Li.Three-dimensionl Finite Element Anlysis of Prt-windings Electric Field of Trnsformer.Proceeding of nterntionl Conference on Electricl chines nd Systems.Seol,Kore,007,1(1):140, 1404.. [] E.Tmki,A.Kishi,S.tohetl.The Coil echnicl Behvior nder Short Circit[C].CGRE Trnsformer Colloqim 1999 in Bdpest,1999,(1 1):1386, 1391. [3] Bose A K.Dynmic response of windings nder short-circit[c].cgre Trnsformer Colloqim 1999 in Bdpest,1999,(1 1):1735-1 1739. [4] Y.Tmsir,Smrydi,H.Gmilng,A.Phrmtrisnti,B.Chyono,R.Siregr.Therml Condition Assessment For Power Trnsformers Operted n Tropicl Condition. Condition onitoring nd Dignosis,CD 008.nterntionl Conference on 1 4April 008 Pge(s): 559-561.
[5] W.H.Tng, K.Sprgeon, Q.H.W nd Z.J. Richrdson.An Evidentil Resoning Approch to Trnsformer Condition Assessments.Power Delivery,EEE Trnsctions on Volme 19, sse 4,Oct.004 Pge(s):1696-1703. [6] Amritpl Singh,E Verm.A Review of ntelligent Dignostic ethods for Condition Assessment of nsltion System in Power Trnsformers.CD 008.nterntionl Conference on 1-4 April 008 Pge(s):1354-1357.