Insulation coordination for wind power plants

Transcription

1 Insultion oordintion for wind power plnts EMTP-RV Stelite meeting Pris, FRANCE August 30, 2018 Prof. Dr. Ivo Uglešić Božidr Filipović-Grčić, PhD Bruno Jurišić, PhD Nin Stipetić, mg.ing. Fulty of Eletril Engineering nd Computing University of Zgre, Croti

2 Overview Insultion oordintion definition Wind Power Plnt hrteristis Chllenges of insultion oordintion in WPPs Exmples in EMTP-RV Temporry overvoltge due to SLGF Vuum iruit reker swithing Diret lightning strikes 1

3 Insultion oordintion The gol of insultion oordintion is uninterrupted nd relile power supply in ll tehnil nd tmospheri onditions. Definition y IEC : Insultion oordintion is the seletion of the dieletri strength of equipment in reltion to the voltge whih n pper on the system for whih the equipment is intended nd tking into ount the servie environment nd hrteristis of the ville protetive devies. The insultion in power system (with ll its omponents) should e designed on the wy to minimize dmge nd interruption to servie s onsequene of stedy stte nd trnsient overvoltges nd this should e done eonomilly. 2

4 Wind power plnt hrteristis Trnsmission system: MVAC, HVAC, HVDC Colletor system: MVAC le network, different topologies Retive ompenstion, filters t POI Min omponents: wind turine genertors (Type 1 Type 5) vuum iruit rekers trnsformers (step-up nd power trnsformer) les 3

5 WPP typil lyout LV/MV step-up trnsformers susttion MV/HV trnsformer feeder rekers WTGs 4

6 Overvoltges in WPPs Lightning trnsients Coupling through susttion trnsformer From diret tower strikes Swithing trnsients Coupling through susttion trnsformer Feeder energiztion Vuum iruit reker swithing (VFFT due to prestrikes nd restrikes) Surge rrester seleted to protet equipment from these Temporry overvoltges Ground fults Feeder islnding, loss of ground referene Cn e higher thn 1.73 pu Continuous operting voltges Higher voltge t remote ends Surge rrester seleted to survive these 5

7 Surge rrester typil plement in MV network djent to the susttion power trnsformer on the feeder side of eh feeder reker t eh interfe etween overhed nd underground feeder setions t the end of eh feeder nd rnh LV surge rresters in the tower 6

8 Insultion oordintion steps Conventionl proess from stndrds (IEEE C62.22, IEC 60071) 1. Selet the surge rrester to e used (MCOV, TOV) 2. Determine the protetive level of seleted surge rrester 3. Determine the lotions for surge rresters 4. Determine the voltge t terminls of the proteted equipment 5. Selet equipment insultion level Evlute voltge protetion mrgins Proedure for WPPs 1. Selet the ville insultion level (limited rnge) 2. Selet rresters needed to protet tht insultion level 3. Determine mount of TOV tht n e withstood TOV mitigtion methods if mrgins re indequte, onsider lterntives: different rrester lotions, higher insultion level... 7

9 Temporry overvoltge due to SLGF 8

10 Exmple 1 Temporry overvoltge: single-line-toground fult, feeder disonnetion nd loss of ground referene

11 Exmple 1 Overvoltge of helthy phses depends on grounding nd WTG type TOV mitigting options: Trnsfer tripping (normly used in new WPPs) High-speed grounding swith Grounding trnsfomer on eh feeder The hoie depends on WTG type R. Wlling, WESC 10

12 ?i 12,25Ohm 1 R19 1m 1 2 RL12 R23 100M Tr0_10?i 12,25Ohm Tr0_11 R20 1m RL R24 100M 1?i 12,25Ohm Tr0_12 R21 1m BUS_A8 RL SW21 SW kV /_0 1 2 R22 100M 1 VwZ / E15 0-1ms 500ms 0 m11 VM?v FDQ20 FDQ BUS_A7 SW20 SW kV /_0 1 2 VwZ / E15 0-1ms 215ms 0 FDQ19 FDQ BUS_A6 SW19 SW kV /_0 1 2 VwZ / E ms 0 FDQ18 FDQ BUS_A5 SW12 SW kV /_0 1 2 VwZ / E15 0-1ms 225ms 0 FDQ17 FDQ BUS_A4 SW11 SW kV /_0 1 2 VwZ / E15 0-1ms 220ms 0 FDQ16 FDQ BUS_A3 SW4 SW kV /_0 1 2 VwZ / E15 0-1ms 215ms 0 FDQ15 FDQ BUS_A2 SW28 SW kV /_0 1 2 VwZ / E ms 0 20ms 1E15 0 FDQ14 FDQ SW37?vi BUS_A1 SW27 SW26 20ms 120ms kV /_0 1 2 SW36?vi VwZ / E ms 0 m8 VM?v m2 VM?v/?v/?v ledt5 CABLE DATA model in: le_33_800_6ph_fd_rv.pun FDQ13 FDQ ledt4 CABLE DATA model in: le_s_100m_33_6fd_rv.pun ledt6 CABLE DATA m10 VM?v DEV9 Vuum iruit reker model DEV10 Vuum iruit reker model DEV11 Vuum iruit reker model?i 2,4Ohm 1 R13 1m 1 2 RL9 R17 100M Tr0_7?i 2,4Ohm Tr0_8 R14 1m RL8 1 2 R18 100M 1?i 2,4Ohm Tr0_9 R15 1m RL7 1 2 R16 100M 1 1nF C1 DY_ nF 33/132 C2 FDQ12 FDQ FDQ2 FDQ Slk: 132kVRMSLL/_0 LF LF1 Phse:0 132kVRMSLL /_0 BUS: VwZ10 Exmple 1 voltge mesurement GT2 fult X GT1 A?i m12 20ms 1E15 0 SW38?vi?i m1 ZnO?vi>e ZNO ZnO?vi>e ZNO model in: rrester.pun ZnO Dt funtion rrester.dt ZnO?vi>e ZNO e_zno e_zno e_zno sope sp1?s sope sp2?s sope sp3?s m13?i A WTG ynd 0.69/33 kv VCB Grounding trnsformer zig-zg 33 kv le network dyn 33/132 kv A?i m3 A 11

13 Exmple 1 GT 2 exluded 1. SLGF ours t 20 ms on phse C 2. Feeder reker opens t 100 ms loss of ground referene 3. WTGs ontinue to generte overvoltge limited

14 Exmple 1 GT inluded 1. SLGF ours t 20 ms on phse C 2. Feeder reker opens t 100 ms loss of ground referene 3. WTGs ontinue to generte overvoltge remins limited

15 Vuum iruit reker swithing 14

16 Prtil prolems with VCB swithing in wind frms The first off-shore wind frms were fed with sustntil trnsformer filures in very erly opertion stge. In the first lrge offshore wind frms Horns Rev nd Middelgrunden (Denmrk), lmost ll of the trnsformers hd to e repled due to insultion filures. It is suspeted tht the swithing of the vuum iruit rekers (VCB) used the trnsformer filures. In order to investigte this phenomenon, lortory setup ws uilt, designed to give n insight into high frequeny trnsients generted during reker swithing in offshore wind frms nd similr le systems. ELECTRICAL TRANSIENT INTERACTION BETWEEN TRANSFORMERS AND THE POWER SYSTEM, CIGRE WG A2/C

17 Vuum iruit reker swithing 16

18 Restrike phenomen during reking of smll indutive urrent 17

19 Restrikes used y VCB swithing ELECTRICAL TRANSIENT INTERACTION BETWEEN TRANSFORMERS AND THE POWER SYSTEM, CIGRE WG A2/C

20 Exmple 2 Filure of power trnsformer 110/25 kv Filure of 25 kv winding 19

21 ZnO 3.5uF C2 ZnO Exmple 2 EMTP-RV model Detiled model of VCB Detiled model of power trnsformer (high-frequeny ehviour) Power trnsformer VCB MV le network (pitive lod) ZnO1 GND AC2 110kVRMSLL /_0 110 kv network d 2 d 1 d 2 d 4 Power trnsformer 4 SS2 Stte Spe Trfo -A5 VCB DEV1 Vuum iruit reker model model in: polimh29.pun ZnO Dt funtion VM m1?v GND ZnO L1 482mH GND 0.100nF GND C3 Cle network 20

22 Simultion results VCB voltge 21

23 Simultion results VCB urrent 22

24 Simultion results VCB urrent 23

25 Simultion results Overvoltge t 25 kv winding of power trnsformer 24

26 Simultion results Overvoltge t 25 kv winding of power trnsformer 25

27 Diret lightning strike to wind turine 26

28 Dmges used y diret lightning strike 27

29 Lightning nd surge protetion for the wind turine 28

30 Plement of the SPDs Exmple: protetion for the genertor SPD ording to EN /IEC Nominl AC voltge (U n ) Mx. ontinuous operting voltge (U ) Nominl dishrge urrent (8/20 µs) (I n ) Mx. dishrge urrent (8/20 µs) (I mx ) Voltge protetion level (U P ) Temporry overvoltge (TOV) type 2/lss II 480 V (50/60 Hz) 600 V (50/60 Hz) 15 ka 25 ka 3 kv 900 V / 5 se. 29

31 TLM3 80 CP TLM4 40 CP ZnO 2.464nF C4 Exmple 3 Diret lightning strike to WT lde Single WTG 3 MVA operting in the viinity of susttion 22/110 kv. Lightning urrent 100 ka 100kA/3us Blde 40 m?i Iigre1 m2 VM?v WTG 3 MVA SM1 SM BUS7 w1b1 VM?v w1b1 VM w1b1?v VM?v FDQ LV_le BUS2 m1 VM?v TR1 0.69/22 kv 3 MVA YD_1 1 2 BUS3 m4 VM?v 22 kv le 2 km FDQ2 FDQ TR2 22/110 kv 15 MVA BUS4 DY_ /110 BUS3 m5 VM?v 123kVRMSLL /_0 f(u) 1 Fm1 Tower 80 m i CABLE DATA model in: lv_le_rv.pun 0,7 kv le 80 m 2.21nF GND C / nF GND C2 ledt1 CABLE DATA model in: ledt1_rv.pun?vi VwZ1 110 kv network C selet 1 2 Sel1 f(u) 1 Fm2 Y I Y 0.04 GND Rn1 I?vi>i GND SPD?vi 700 ZnO1 model in: rresterlv.pun ZnO Dt funtion Grounding resistne 50 Ω (ioniztion inluded) 30

32 Exmple 3 lightning urrent distriution / ioniztion Lightning urrent Current through grounding resistne Potentil rise t grounding resistne Grounding resistne 31

33 Exmple 3 overvoltges t TR1 nd WTG terminls Overvoltges t 0.69 kv side of TR1 Trnsferred overvoltges t 22 kv side of TR1 Overvoltges t WTG terminls 32

34 Exmple 3 SPD onneted in neutrl point of TR1 nd idelly grounded Overvoltges t 0.69 kv side of TR1 Trnsferred overvoltges t 22 kv side of TR1 Overvoltges t WTG terminls 33

35 Conlusion Different pprohes for reduing TOVs due to SLGF re investigted. Simultions hve shown tht pplition of grounding trnsformer effiintly redues TOVs during SLGF. EMTP-RV simultions onfimed the ft tht VCB swithing produes VFTOs whih re not high in mgnitude, ut due to high freqeny, the distriution ross the trnsformer winding is nonliner. This my use dieletri rekdown of trnsformer insultion system. The results of diret lightning strike simultion indite tht use of pproprite SPDs is ruil in order to protet the vulnerle eletroni equipment. However, the effiient opertion of SPDs depends on grounding resistne vlue whih should e kept s low s possile. 34

36 Insultion oordintion for wind power plnts EMTP-RV Stelite meeting Pris, FRANCE August 30, 2018 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)