Analysis of transient recovery voltage on SF 6 circuit breakers when switching unloaded 400 kv transmission lines

Transcription

1 The 12 th Interntionl Symposium on High-Voltge Tehnique "Höfler's Dys", Novemer 2015, Portorož, Sloveni. 1 Anlysis of trnsient reovery voltge on SF 6 iruit rekers when swithing unloded 400 kv trnsmission lines Božidr Filipović-Grčić, Ivo Uglešić, Srećko Bojić Astrt This pper presents nlysis of trnsient reovery voltge (TRV) on SF6 iruit rekers (CBs) when swithing unloded 400 kv trnsmission lines. On site testing of iruit rekers ws performed when swithing unloded 400 kv trnsmission lines. Swithing ws performed with nd without onneted in prllel to CB reking hmers. Simultions were onduted in EMTP-RV softwre [1] nd lultion results were ompred to on-site mesurements. Index Terms SF6 iruit reker, trnsient reovery voltge, EMTV-RV simultions, unloded 400 kv trnsmission line, on site testing. W I. INTRODUCTION HEN n unloded line is regulrly swithed-off the eletri r distinguishing ours t urrent nturl zerorossing. Voltge on the line side remin highest in the phse whih is firstly swithed-off due to the eletromgneti oupling of the other phses nd due to Ferrnti effet. In se when pitor voltge trnsformers re instlled on oth sides of the line the dishrging of trpped hrge is slow. Suh dishrging depends on wether onditions, minly on humidity. So, the trpped hrge hs very signifint influene on CB trnsient reovery voltge. Besides the pek vlue of TRV the voltge distriution etween reking hmers is very importnt for CB dieletri stresses during swithing opertions. In se when CB is not equipped with pretty unequl voltge distriution etween reking hmers ours nd this in some ses my led to CB filure. The voltge distriution etween the reking hmers ould e improved y instlling the, whih re espeilly importnt in ses when swithing-off reltively long lines. This pper presents nlysis of trnsient reovery voltge TRV on SF 6 CBs when swithing unloded 400 kv trnsmission lines. On-site mesurements on two swithing onfigurtions in trnsmission network were performed in order to verify the performne of CBs with nd without. Mesurements were ompred to lultions results otined from the model developed in EMTP-RV softwre. II. MODELING OF TEST CONFIGURATIONS IN EMTP-RV Figs. 1 nd 2 show test onfigurtions 1 nd 2. Susttion B Susttion C Power trnsformer 1 400/110 kv TL1 Power trnsformer 2 400/110 kv CB swithing TL2 Susttion A Power trnsformer 3 400/110 kv TL3 Bus oupler y Min usrs uxiliry usrs Auxiliry usrs TL4 Min usrs 1 Min usrs 2 Current mesurement Voltge mesurement Fig. 1. Test onfigurtion 1: Testing of iruit reker in 400 kv line y TL2 when swithing unloded trnsmission line TL2 TS ŽERJAVINEC mjerenje struje mjerenje npon T1 Tumri T2 Ernestinovo T4 Spojno polje GS-PS PS Heviz 1 Heviz 2 GS1 GS2 B. Filipović-Grčić nd I. Uglešić re with the University of Zgre, Fulty of Eletril Engineering nd Computing, Unsk 3, Zgre, Croti (e-mil: ozidr.filipovi-gri@fer.hr; ivo.uglesi@fer.hr). S. Bojić is with Energy Institute In., Ul. grd Vukovr 37, Zgre, Croti (e-mil: sreko.oji@ie-zgre.hr). TS TUMBRI TS ERNESTINOVO TS HEVIZ Fig. 2. Configurtion 2: Testing of iruit reker in 400 kv line y TL2 when swithing unloded trnsmission lines TL2 nd TL3

2 The 12 th Interntionl Symposium on High-Voltge Tehnique "Höfler's Dys", Novemer 2015, Portorož, Sloveni. 2 The simultion model inludes the 400 kv susttions nd onneted trnsmission lines shown in Figs. 1 nd 2. The equipment in high voltge susttion ws represented y surge pitnes, wheres trnsmission lines, usrs nd onneting leds y frequeny depending model [2, 3]. ondutors ACSR 490/65 mm 2 re undled nd onsist of 2 su-ondutors seprted y distne of 0.4 m. Lengths of the trnsmission lines: TL1 62 km; TL2 230 km; TL3 nd TL4 (doule-iruit trnsmission line) 167,8 km. The phse trnspositions of the trnsmission line TL2 hve een tken into ount (Fig. 3). Towers of the trnsmission line TL1 re shown in Fig 4. Fig. 3. Trnspositions on 400 kv trnsmission line TL2 10,5 m 10,5 m 6 m Fig. 5. Position of ondutors t towers nd their verge heights (first setion of trnsmission line km) 11 m Fig. 4. Towers of the trnsmission line TL1 The position of ondutors t towers nd their verge heights for doule-iruit trnsmission line (TL3 nd TL4) re shown in Figs. 5 nd 6. The model of CB with two reking hmers is shown in Fig. 7. The pitne etween the open ontts of reking hmers is 10 pf nd inherent erth pitnes were tken into ount s depited in Fig. 7. Busrs in 400 kv susttions re mde of luminum lloy E-AlMgSi F 22. Outside pipe dimeter is 220 mm nd internl dimeter is 204 mm. Fig. 6. Position of ondutors t towers nd their verge heights (seond setion of trnsmission line km) C 1 C k CB ontts Breking hmer 1 C k CB ontts Breking C C hmer 2 2 Fig. 7. Model of SF6 iruit reker with two rking hmers

3 CP The 12 th Interntionl Symposium on High-Voltge Tehnique "Höfler's Dys", Novemer 2015, Portorož, Sloveni. 3 nf nf SW1 i SW11 i Susttion D m5 VM BUS22 zerjvine_grni model in: zerjvine_grni_rv.pun zerjvine_grni_rv.lin Heviz_grni model in: heviz_grni_rv.pun heviz_grni_rv.lin m6 VM BUS20 C106 nf 0.06nF C103 Susttion A 5.52nF VM m7 C51 Cpitnes of pprtus in line y line1 linedt1 model in: km_39_rv.pun km_39_rv.lin m1 VM line2 linedt2 model in: km_68_rv.pun Trnsmission line TL2 m2 VM line3 linedt3 model in: km_85_rv.pun km_85_rv.lin m3 VM TLM E00 linedt4 line11 model in: km_6_rv.sv Trnsmission line TL3 m4 VM linedt6 model in: km_30_rv_rv.pun km_30_rv.lin line13 line12 line5 linedt5 model in: km_31_rv.pun km_31_rv.lin Trnsmission line TL1 Cpitnes of pprtus in line y Swithing with SF6 iruit reker Susttion B 6.14nF Cpitnes of pprtus in line y C99 linedt7 model in: glvne_sirnie630m_rv.pun BUS17 190_m_sirnie Busrs 10x120 pf Busr support insultors Susttion C RL17 nf C105 BUS18 m16 VM BUS21 BUS2 m15 VM 6.14nF C100 C111 C116 SW27 i nf SW29 i 0.06nF C nF C113 nf SW28 i SW30 i C110 C115 BUS18 BUS15 40_m_sirnie 1.2nF C101 BUS3 AC1 408kVRMSLL /_0 Network equivlent Fig. 8. EMTP-RV model of the of 400 kv trnsmission network The equipment in high voltge susttion ws represented y the following pitnes to ground [2]: urrent trnsformers 680 pf, pitive voltge trnsformers 4400 pf, indutive voltge trnsformers 550 pf, disonnetors 200 pf, iruit rekers 60 pf, usr support insultors 120 pf, power trnsformers 2700 pf. During the testing oth swithing onfigurtions were supplied from the 400 kv susttion C with onneted two trnsmission lines nd power trnsformer 400/110 kv. The equivlent networks were represented with voltge soure in series with sequenes impednes, whih re otined from short iruit urrents for the nlyzed swithing onfigurtions. EMTP-RV model of the of 400 kv trnsmission network is shown in Fig. 8. A. Test onfigurtion 1 Testing of iruit reker in 400 kv line y TL2 ws performed when swithing unloded 230 km trnsmission line TL2. Currents nd voltges were mesured in susttion B t TL2 y nd voltges were mesured t us oupler y. Cpitive voltge trnsformers re instlled t oth ends of trnsmission line TL2. During the testing oth swithing onfigurtions were supplied from the 400 kv susttion C with onneted two trnsmission lines nd power trnsformer 400/110 kv. Tles 1 nd 2 show lultion results nd mesurements (RMS vlues) in sttionry stte fter energiztion of trnsmission line TL2. Swithing off unloded trnsmission line TL2 ws nlyzed in EMTP-RV. When n unloded line is regulrly swithed-off eletri r extinguishes t urrent nturl zero-rossing [3]. Opening of CB ontts ws simulted t t=20 ms nd eletri r extinguishes when pitive urrents reh zero-rossing point in ll three phses (Fig. 9). Trpped hrge remins on the line side fter opening of CB (Fig. 10). The voltge is highest in the phse C whih is firstly swithed-off due to the eletromgneti oupling of the other phses [4, 5]. TRV on CB is shown in Fig 11, while distriution of TRV ross the reking hmers is shown in Fig. 12. Tle 1. Mesurements (RMS vlues) in sttionry stte fter energiztion of trnsmission line TL2 Urms t Irms t Urms t susttion B susttion B susttion A A 427 kv B 428 kv 214 A 443,7 kv C 427 kv Tle 2. Clultion results (RMS vlues) in sttionry stte fter energiztion of trnsmission line TL2 Urms t Irms t Urms t susttion B susttion B susttion A A 429,1 kv 205,1 A 442,5 kv B 429,1 kv 206,3 A 442,4 kv C 429,3 kv 207,4 A 442,2 kv Fig. 9. Currents when swithing off unloded trnsmission line TL2 A B C Fig. 10. Voltges on the line side in susttion B

4 The 12 th Interntionl Symposium on High-Voltge Tehnique "Höfler's Dys", Novemer 2015, Portorož, Sloveni. 4 The following distriution of TRV pek vlues ross reking hmers in phse A is otined: 366,5/327,8 kv, (52,8/47,2 %). Simultions were lso performed in se of 1600 pf nd 2000 pf nd in eh se mximum rte of rise of reovery voltge (RRRV) ws determined. Clultion results re shown in Tle 3. Fig. 11. TRV on CB without Besides the pek vlue of TRV the voltge distriution etween reking hmers is very importnt for CB dieletri stresses during swithing opertions. Fig. 12 shows distriution of TRV ross reking hmers in se without. Fig. 12. Distriution of TRV ross reking hmers in phse A (without ) Simultion results show pretty unequl voltge distriution etween reking hmers. The gretest prt of TRV stresses the reking hmer 1 loser to the susttion. Clultion results show the following distriution of TRV pek vlues ross reking hmers in phse A: 603,7/92,9 kv, (86,7/13,3 %). Further nlyses show the influene of on voltge distriution etween reking hmers. Totl TRV on CB remins the sme s in the se without, while signifint improvement of voltge distriution nd redution of TRV mplitude ross the reking hmers is hieved (Fig. 13). Tle 3. Comprison etween lultion results nd mesurements of TRV on CBs in susttion B fter swithing off unloded trnsmission line TL2 TRV mplitude TRV mplitude on reking on reking TRV Mximum hmer 2 hmer 1 mplitude RRRV on loser to loser to on CB (kv) CB (kv/µs) trnsmission susttion (kv) line (kv) instlled A 603,7 92,9 694,3 0,1203 B 603,9 79,4 682,0 0,1280 C 613,4 131,4 744,6 0,1342 instlled A 366,5 327,8 694,2 0,1197 B 360,8 321,2 682,1 0,1231 C 390,5 354,1 744,7 0,1244 instlled 1600 pf A 353,4 340,8 694,2 0,1203 B 347,5 334,6 682,2 0,1324 C 378,3 366,5 744,8 0,1376 instlled 2000 pf A 352,1 342,0 694,2 0,1183 B 346,3 335,9 682,2 0,1240 C 377,2 367,7 744,8 0,1084 Tle 4 shows omprison etween lultion results nd mesurements of TRV on CBs in susttion B fter swithing off unloded trnsmission line TL2. Tle 4. Comprison etween lultion results nd mesurements of TRV mplitude on CBs fter swithing off TL2 Mesurement Clultion results A 699,4 700,3 694,3 694,2 B 671,0 673,4 682,0 682,1 C 717,8 719,7 744,6 744,7 Tles 5 nd 6 show omprison of voltge mplitudes from the oth sides of CBs (line side nd susttion side). Mesurements were rried out in se without nd with. Tle 5. Comprison etween lultion results nd mesurements of voltge mplitudes t 400 kv usrs in susttion B fter swithing off TL2 Mesurement Clultion results 500 pf 500 pf A 358,7 358,0 351,1 351,1 B 352,2 351,9 352,4 352,4 C 347,0 346,0 350,5 350,5 Fig. 13. Distriution of TRV ross reking hmers in phse A (with )

5 The 12 th Interntionl Symposium on High-Voltge Tehnique "Höfler's Dys", Novemer 2015, Portorož, Sloveni. 5 Tle 6. Comprison etween lultion results nd mesurements of voltge mplitudes t 400 kv line y in susttion B fter swithing off TL2 Mesurement Clultion results A 358,0 356,0 367,6 367,6 B 349,2 347,9 357,6 357,6 C 385,8 386,4 402,3 402,2 B. Test onfigurtion 2 Testing of iruit reker in 400 kv line y TL2 ws performed when swithing unloded trnsmission lines TL2 (230 km) nd TL3 (167,8 km). Beginning nd end of the trnsmission line TL3 ws disonneted from ll other pprtus in line ys inluding indutive voltge trnsformers. Cpitive voltge trnsformers re instlled t oth ends of trnsmission line TL2. During the testing susttion B ws supplied from the 400 kv susttion C with onneted two trnsmission lines nd power trnsformer 400/110 kv. Tles 7 nd 8 show the omprison of lultion results nd mesurements (RMS vlues) in sttionry stte fter energiztion of trnsmission lines TL2 nd TL3. Tle 7. Mesurements fter energiztion of trnsmission lines TL2 nd TL3 Urms t Irms t Urms t susttion susttion B A/C A B C susttion B 434 kv 436 kv 435 kv 386 A 451,5 kv/ 422,6 kv Tle 8. Clultion results fter energiztion of trnsmission lines TL2 nd TL3 Urms t Irms t Urms t susttion susttion B susttion B A/C A 438,2 kv 360 A 451,8 kv/ 422,9 kv B 438,4 kv 376 A 452,0 kv/ 423,6 kv C 438,9 kv 368,4 A 451,6 kv/ 423,2 kv Simultions were performed in se of 1600 pf nd 2000 pf nd in eh se mximum rte of rise of reovery voltge (RRRV) ws determined. Clultion results re shown in Tle 9. Tle 10 shows omprison etween lultions nd mesurements of TRV mplitude on CBs in susttion B fter swithing off unloded trnsmission lines TL2 nd TL3. Tles 11 nd 12 show omprison of voltge mplitudes from the oth sides of CBs (line side nd susttion side). Mesurements were rried out for two ses: without nd with. Tle 9. Comprison etween lultion results nd mesurements of TRV on CBs in susttion B fter swithing off unloded trnsmission lines TL2 nd TL3 TRV mplitude on reking hmer 1 loser to susttion (kv) TRV mplitude on reking hmer 2 loser to trnsmission line (kv) TRV mplitude on CB (kv) Mximum RRRV on CB (kv/µs) instlled A 618,6 94,4 712,9 0,1367 B 611,6 73,8 685,3 0,1761 C 628,5 122,9 751,0 0,1746 instlled A 376,2 336,7 712,9 0,1323 B 363,0 322,4 685,3 0,1683 C 394,6 356,4 751,1 0,1828 instlled 1600 pf A 362,9 350,0 712,9 0,1045 B 349,3 336,1 685,4 0,1253 C 381,8 369,4 751,2 0,1455 instlled 2000 pf A 361,6 351,3 712,9 0,1075 B 348,0 337,4 685,4 0,1391 C 380,6 370,6 751,1 0,1573 Tle 10. Comprison etween lultion results nd mesurements of TRV mplitude on CBs fter swithing off unloded trnsmission lines TL2 nd TL3 Mesurement Clultion results A 706,7 696,3 712,9 712,9 B 672,4 676,1 685,3 685,3 C 730,1 722,2 751,0 751,1 Tle 11. Comprison etween lultion results nd mesurements of voltge mplitudes t 400 kv usrs in susttion B fter swithing off unloded trnsmission lines TL2 nd TL3 Mesurement Clultion results A 368,8 369,5 359,4 359,4 B 362,9 358,5 362,3 362,3 C 357,7 355,5 358,3 358,3 Tle 12. Comprison etween lultion results nd mesurements of voltge mplitudes t 400 kv line y in susttion B fter swithing off unloded trnsmission lines TL2 nd TL3 Mesurement Clultion results A 365,4 369,1 370,4 370,4 B 355,7 353,5 362,3 362,3 C 396,6 391,7 397,8 397,8

6 The 12 th Interntionl Symposium on High-Voltge Tehnique "Höfler's Dys", Novemer 2015, Portorož, Sloveni. 6 III. CONCLUSION On site testing of iruit rekers ws performed when swithing unloded 400 kv trnsmission lines. Swithing ws performed with nd without onneted in prllel to CB reking hmers. Simultions were onduted in EMTP-RV softwre nd lultion results were ompred to on-site mesurements. The lultion results give slightly higher TRV mplitudes ompred to mesurements (mximum differene 20 kv). This is eptle nd expeted, sine the eletri r resistne ws not tken into ount in simultions. Moreover, mesurement iruit introdues ertin ttenution nd distortion of the reorded voltge wveforms. Signifint improvement of voltge distriution nd redution of TRV mplitude ross the reking hmers is hieved with pplition of. Similr lultion proedure ould e performed prior to on site testing in order to ssess the level of swithing overvoltges in trnsmission network. IV. ACKNOWLEDGMENT This work hs een supported in prt y the Crotin Siene Foundtion under the projet Development of dvned high voltge systems y pplition of new informtion nd ommunition tehnologies (DAHVAT). REFERENCES [1] EMTP-RV, doumenttion, WEB site [2] A. F. Imee, D. W. Durk, H. Elhi, S. Kolluri, A. Lux, D. Mder, T. E. MDemott, A. Morhed, A. M. Mous, R. Ntrjn, L. Rugeles, E. Trsiewiz, Modeling Guidelines for Fst Front Trnsients, Report prepred y the Fst Front Trnsients Tsk Fore of the IEEE Modeling nd Anlysis of System Trnsients Working Group, IEEE Trnstions on Power Delivery, Vol. 11, No. 1, Jnury 1996.Ruen D. Grzon: High Voltge Ciruit Brekers, Design nd Applitions. [3] CIGRE, Working Group of Study Committee 13: Stte of the Art of Ciruit-Breker Modelling, Deemer [4] R. W. Alexnder, D. Dufournet, Trnsient reovery voltges (TRVs) for high-voltge iruit rekers, IEEE Tutoril, Otoer 16 th 2008, Clgry, Cnd. [5] IEC : High-voltge swithger nd ontrolger; High-voltge lternting-urrent iruitrekers, 2003.