ML18127A838
| ML18127A838 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 05/20/1977 |
| From: | Florida Power & Light Co |
| To: | |
| References | |
| Download: ML18127A838 (16) | |
Text
P R EL IMI NARY REPORT 0 N SYSTEM DISTURBANCE MAY 16, 1977 FLOR I DA POWER 5 L I GHT COMPANY MAY 20, 1977 TABLE OF CONTENTS Introduction Surrmary Description of Disturbance Loss of Turkey Point Unit 3 Loss of the Ft.Myers-Ranch 240kV Line Initial Service Restoration PAGE Loss of the Andytown-Orange River 500kV Line Service Restoration System Conditions Figure 1-Map of Area Affected-Loss of Turkey Point 3 and Ft.Myers-Ranch 240kV Line Figure 2-Area Loads and Generation Figure 3-Area Loads and Generation Figure 4-Net Unit Capabilities at 10:08 AM Figure 5-Summary of Relay and Breaker Operations Figure 6-Sequence of Events Figure 7-Area Loads and Generation Figure 8-Hap of Area Affected-Loss of Orange River 500kV Line 10 12 13 INTRODUCTION Florida Power 5 Light Company experienced a major outage on May 16, 1977, that extended from Ft.Pierce southward along the East Coast to the Florida Keys'igh speed oscillograph records, recording charts, and other data have been examined in order to reconstruct the sequence of events that occurred.This report documents the initial analysis.In-depth analysis will be done to determine specific cause and effect of the operations given in this report.
SUMMARY
The outage was triggered at 10:24 a.m.when the heavily loaded Ft.Myers-Ranch 240kY line tripped due to a phase-to-ground fault.The east and south areas of the system immediately became separated from the north and west areas when three 240kV and seven 138kV lines relayed sequentially due to instability.
This split of the transmission system resulted in the St.Lucie Plant of the east area being tied only to the north area and the Riviera Plant being islanded along with part of the east area load.The south area and the balance of the east area thus became an isolated area with Port Everglades and Turkey Point Plants generating 1003 MW to supply approximately 2950 MW of load.(See Figures 1 and 2.)This load-generation imbalance resulted in a very rapid drop in frequency to below 56 Hz.Underfrequency relays operated to shed approximately 50/of the load.The four units operating at Port Everglades and Turkey Point Plants became swamped and tripped off.The Riviera Plant was shut down about 10:30 a.m.due to operational problems following load rejection.
The outage then extended from Ft.Pierce to the Florida Keys and affected approximately 1,300,000 customers.
Service was restored to almost all customers by 3:00 p.m.The east and south areas had been importing approximately 1140 MW just prior to the system split due to the earlier forced outage of Turkey Point Unit 3 at 10:08 a.m.This generation loss of 684 MW had isolated Peninsular Florida but the combined spinning reserve of the Florida systems had been sufficient to cover the loss and arrest the frequency decline at 59.59 Hz.At 10:14 a.m., Peninsular Florida had been tied back to the systems to the north and operating conditions stabilized.
See Figures 3 and 4 for details of inter-area flows, tie flows, loads, generation and spinning reserve.DESCRIPTION OF DISTURBANCE LOSS OF TURKEY POINT UNIT 3 At 10:08 a.m., May 16, 1977, Turkey Point Unit 3 experienced a reactor and turbine trip as a result of a false relay operation.
Chattering contacts in a sensing relay in a reactor coolant pump breaker monitor circuit gave false indication of the loss of a reactor coolant pump.A reactor trip was then initiated since Turkey Point generation was 684 MW.The north-south lines in the state of Florida relayed, isolating the peninsula from the north.The frequency dropped to 59.59 Hz as a result of governor response.At 10:14 a.m., the tie to the north was re-established and the frequency returned to 60 Hz.There was a heavy import of power south, but was reducing in magnitude.
Voltage at St.Lucie Plant 240kV bus was 219kV.
LOSS OF THE FT.MYERS-RANCH 240KV LINE At 10:24 a.m., the Ft.Myers-Ranch 240kV line relayed due to phase-to-ground fault near Ft.Myers.Just prior to this relay action the line was carrying approximately 420 MW.The loss of the Ft.Myers-Ranch 240kV line resulted in a further increase in flow south of Malabar.This power swing caused the separation of the system at 10:24 a.m.(See Figure 1.)The sequence of relay and breaker operations is given in Figure 5.Approximately four seconds later, St.Lucie Unit 1 reactor was tripped manually following a run back of the unit.Riviera Units 3 and 4 were isolated into an area with 105 MW of load.The Riviera units were carrying approximately 532 MW prior to the separation of the system.After approx-imately six minutes, the generator breakers at Riviera were opened in order I to stabilize the units.The frequency in the remaining affected area decreased rapidly due to Turkey Point Units 1 and 2 and Port Everglades Units 1 and 3 with 1003 MW of generation being left to serve approximately 2957 MW of load (See Figure 2.)Within two seconds, frequency dropped below 56 Hz.As the frequency gay~Z~4 dropped, underfrequency relays shed approximately 1544 MW in s'tages beginning at 59.2 Hz and completing the shed at 57.1 Hz.Turkey Point Unit 2 and Port Everglades Unit 3 tripped with low bearing oil pressure signal.Port Everglades Unit 1 and Turkey Point Unit 1 were tripped by operation of generator underfrequency protection set at 57.0 Hz with a 12-second delay.See Figure 6 for a sequence of events for the affected plants during the disturbance.
The remainder of the system, north and west of the split, went into high frequency but recovered to 60 Hz and the north-south ties were re-established.
The remaining system load was H58 MW and 1798 MW of g lfO.0C generation.
Net export was 240 MW nti'chedu/ed interchange was re-established.
INITIAL SERVICE RESTORATION The Power Coordinators proceeded to identify the affected area and reconnect the system.Restoration proceeded from the north by energizing the 240kV transmission lines to the south.At 12:03 p.m., the total system load was 3408 MW with 3318 MW of generation and 90 MW of import from neighboring utilities.
LOSS OF THE ANDYTOWN-ORANGE RIVER 500KV LINE At 32:03 p.m., the fault pressure relay on the"A" phase 240/500kV autotransformers at Andytown operated incorrectly when the auxiliary cooling pumps were started.Approximately 652 MW were being carried on the 500kV circuit when tripped was initiated.
See Figure 7 for load, generation, and inter-area flow data.This initiated a power swing which resulted in the separation of the east and south areas at Malabar.See Figure 8 for the area affected.All generation in the affected area was separated by underfrequency generator protection and overcurrent relay operation.
SERVICE RESTORATION The affected area was quickly identified and immediate restoration
,.....~proceeded from the north.Gas turbines quickly picked up isolated areas and were re-synchronized with the system.Startup power was provided to II the steam units rapidly from the restored 240kV system.
Service was restored to all but a few isolated areas by 3:00 p.m.There was no damage to generating equipment or to nuclear reactors.All units were returned to service during the day after safety inspections were complete.SYSTEH CONDITIONS P rior to the disturbance, the system 1oad was 4660 WW with generation of 4710 HH.The system spinning reserve was 400 HM with an additional 1022 HM of available steam reserve and 1571 HW of fast start combustion turbines and diesels.All line flows were well within limits.Area loads and generation data is given in Figure 3 for the loss of Turkey Point Unit 3 i disturbance, Figure 2 for the loss of the Ft.Hyers-Ranch 240kV line,'and Figure 7 for the loss of the Andytown-Orange River 500kV line.Figure 4 gives the unit loading and reserves at 10:08 a.m.prior to any disturbances.
Figure 5 lists the relay actions occurring during the disturbances.
Figure 1 Ac PECTED/'L>>t>>r SL>>IW~~ee>>tr 1<<o 0<<ti I~ig I tie rteefrtre~~I I t s~r<<I Iw W NI~I le<<I I 0<<I I 140 L rr~<<C r~I toe<<tea I~I I I>>IO<<T Isee.0<<<<ovaaee 4e Cf y Cg I L<<l<<N'ra<<40>>>>~te>>a~Q et<<ra~I~~SYSTEM DXSTUBSANCE AREAS LNAY 16I 1977 V r<<C LOSS QF TP 03 9 10:08 AN I~W N>>~~~~0~<<~~~N<<N I~i.000~0 Itt~1 N>>lt>>I~I<<I~I IWI>>>>~~0<<>>I h<<or>>I~I I~t~e 00 II~<<<<<<I Io<>~r<<e all~II~~tl~~<<>>'t>>0 II I>>>>l I~>>to<<>>&0<<1~00~It~~~~<<I I<<~I~4~0~IWL4 I~~~'A~A 1>>o I N 00<<e rcrfe 0'p P 4IIC it I LI I!r>>r Ifafre CO~oeetre 6 NT>><<era C t I I!I te~j<<II M ft I'Q LIQRTH AREA M.,0..CPS!>>Ieatsc I>>~V<<00\4~Wewt~~<<N>>4>>0>>I~<<>>II I>>N ho>>Nwe I lr~"'EST ear<<LM I IIIrtr Wt~o<<wr c<<oo oo~~o<<eos I~I 1<<e..h>>Ie<<IL to rtr I JOKED T.NYERS-RACNCH 240KV Ll'.CE 8 10:24 AN IIII~~~<<0 II<<f~>>ave~~10 W~0>><><<4 IN IN>><<>>I<<\I>>I<<>>4>><<<<It<<I~ere>>>>>>>>te>>0th w Ittor>>I e II~r Lr OMT>>~~..I Ihe fe~<<>>00!I 0<<Ito 0 EDlt<<O~N>>~L~>>0<<~~~I 000~I 0<<I~te~to 1 e>>N>><<~I~~~11~'>>l~'I AI~~>>eo~>>I~Lot~I I 014 e<<o<<vj'0.I!.II~I I et 0-~~P I g-~-Wrest-lil,~."i','Sg II STOSTarae aeo<<ret S Tea<<a<<ssae srs~ca waar OIL<<~CSCN Vf~OC~C C C 0 I I I I!I Iat 1 at Isl I~I~Wll OLLI'4>>TP~N NI I N'IN I<<I~al e<<<<eoo I+3~~\SCa OT Cae IT e S~IT~\re saceaoara caeeC~ts ac Co>>c CTN<<To>>so<<scar scores 1044~~thOT>>h,ge b.<<<<ee I~L, oer<<SUBSTATION ANO YIIANSMISSION SYSTEM FS.Cae~ICIER a I.SGSCI Ch.STI I N 4aTI att>>aeaeseec~Careafte sleet co st>>acta Is~~0 motte>>Sto 00 co,st<<eel>>0.
Is IT secaatao!00 IT csesehlctao, as IT Meat>>I.So IT Cs<<CTTTO~ao 00 cecaanoa a ae co sehrcrae la 00 ceceatae I'y r<<solar cc>>slhrceaestole eNcratae~I~4<<acecaaTM OL<<tl 10<<e'<<>>>>wh acecttIM teart<<te eaesrc<<<<OTIN ot 0000$04se>>ooctaac Tate<<<<ss oe seastatha>>>>es>>ssae seaaeltao NTT ta voeeatloe cr taws>>sooe Toataac s ST<<omo srastatae~>>~~C>><<el ae a<<tee+4~00t!S~IIDl figure 2 EvENT loss of ft.M ers-Ranch 240kV Line TIME]Net Interchange Before After 527 in 240 out NORTH BEFORE AFTER Outside Ties 367 B 80 A LOAD GEN.722 899 705 806 320 A 160 B 181 A 544 B/'OAD GEN.WEST B:.F'R-1175 AFTER 672 992 595 B LOAD GEe>~EAST BEFORE 792*1286 AFTER 286 105 0 A 0 A 1633 B Out SOUTH B:-..ORE 2636 AF:.R 0 GEN.1003 SYSTEM I LOAD GEN.BEFORE 4890 4363 A" TER 1663 1903 A=After B=Before*321 A~IW isolated with South area after system split.
Figure 3 I zvzNT Loss of Turke Point 83 TXrCE 10:08 a.m.Net Znte change Before After 50 out 501 in~15 B~341 A LOAD GBN.NORTH BEFORE AFTER Outside Ties 35'1604 A 475 A 62 B LOAD GEN.iZST BE.".ORE 705 1030 AFT F.r 710 1112 290 Bm 562 A-p LOAD EAST'BE.ORE 715 1255 A".T:-R 755 1308 1590 A 892 B Open LOAD SOUTH oe-2560 A: T:.R 2590 GBN.1668 1000 SY STRE LOAD BBE OR:-4660 4735 G:-N.4710 4234 A=A te B=Before Figure 4 I RLT:3f FLORIDA POWER&LIGHT COMPANY NET UNIT CAPABILITY-MW AT 10:08 AM MAY 16, 1977 PLANT UNIT CONTINUOUS RATE M+P~ACTUAL LOAD SR NORMAL LIMITATION TPNl TP02 TPN3 TPN4 FL54 FLS5 PE51 PEN2 PEN3 PEÃ4 369 369 681 681 138 138 205 205 368 368 369 185 681 0 0 0 90 0 368 0 328 188 684 0 0 0 90 38 340 0 41 0 0 0 0 28 5 PM 7-17-77 RFC 12:30P RFC 2:OOP RFC ll:OOA 5-28-77 Seal leak"A" BFP.Refuel.Condenser leak.Not released.Overhaul.3522 1693 1668 69 RVS3~vN4 111 273 273 809 273 273 751 501 754 45 Unknown Heater drain pump out.1355 1297 1255 CCSl CC11 2 SNN3 SNÃ4 SN115 369 364 138 370 370 369 173 0 370 0 333 166 0 258 0 36 7 61 5-18-77 RFC 2:OOP RFC 1: OOP 2B FD fan motor repair.1611 912 757 104 FM52 MT51 138 369 772 138 369 772 106 339 585 23 30 129 1279 1279 1030 182 STEJQ1 7767 5181 4710 400 DSL GTPE GTF L GTFM 27 338 676 612 24 310 676 561 0 0 0 0 0 0 0 0 5-16>>77 5-20-77 PE 02 will not start.512 maint.519 base only.I7 gen.ground.1653 1571 TOTAL 9420 6752 4710 400 Scheduled interchange
=0 Expected Mon.a.m.peak=5000 Weather: Mostly suey today and Wind East 10 MPH.Required Spinning Reserve=337 Sun.p.m.peak was 4442 MW.Tuesday.Hi in lo 80's.Lo in lo 70's.
SYSTEM Dl STURBANCE SUMHARY OF RELAY AND BREAKER OPERATIONS TIME]0:08AM 10:09:50RH 0 (10: 24AM)STAT I ON Turkey Point Port Evergia<les Ranch Unit//3 Uni t//2 CIRCUITS Fort Hyers-Ranch 240kV f VL'NTS Tripped Tripped Opened GP REHARKS Unl'nown 53 Cy 55 Cy 60 Cy(approx)
Fort Hyers For t Hyers Halabar Midway Ranch Fort Hyers-Ranch 240kV Fort Myers Ranch l38I<V Opened Opened Midway-Ranch 240kV Pratt 6 Whitney-Ranch 240kV Opened Opened Mal abar-Hi dway 240kV No.1 Opened PP, Zl., G I A,B>C, PP A,B, PP,Z)ApB,PP,Zl A~Zl 60 Cy(approx)
Pratt f.Whitney Pratt G Whitney-Ranch 240kV Opened BpCpZ'3 y8 CV(aVV~ox) 78 Cy(approx)
Unknown Unknown Broward Ranch llartman llartman Broward-Ranch l38kV Broward-Ranch 3.38kV liartman-Midway 69kV llartman-Midway 69I<V Opened Opened Opened Reclosed A,C,PP A,C, PP T I I'lE STATION CIRCUITS EVENTS REHARKS O'I Cy(approx) 85 Cy(approx) 00 Cy(approx) 00 Cy(approx)
<)0 Cy(approx)
.1.00 Cy(approx)
Riviera Riviera Il i dway P lumosus Ranch Ranch Hidway-Plumosus 130I<V Hi dway-Pluinosus 138I<V Ranch-Riviera 138kV No.l Ranch-West Palm Beach 138I<V Opened Opened Opened Opened Ranch-Riviera 138I V No.2 Opened Ranch-Riviera 130I<V No.3 Opened B,Cp Z2 B,C,Z2 A,B,C,PP A,BpC,Z3 C,PP,Zl 127 Cy(approx)
Ranch l>I3 Cy(approx)
Ranch 280 Cy(approx)
St.Lucie Ranch-West Palm Beach 138I<V Ranch-West Pahn Beach 130I<V Unit/ll Reclosed Opened Tripped C, PP,Z1 4~~~~~~I I I'~I'.~~~~I I~~~~~'~I I~~I~~~~~~~~l:~~~~I I~\~~~~, I I~~~i.~~~~~~~I I I~.~~~~~~, I~~I I~~~~.'1~~II I'~~.~~I S~e I~~~I I~~~I~~~~~~t~~~~~~~~~~~~~~~~I~.~~\I I~',.o~~I Figure 7".--.--: """)r'-" I J~~~~J'vENT Loss of And town-Oran e River 500kV TIVE 12: 03.m.Net Interchange Before After 90 in 516 out NORTH BEFORE A.TER 30 B LOAD 740 721 6 A GEN.1004 727 510 A 60B 0 A 294 B tI:S':-OF:.AFTER EAST BEFORE A:-TER LOAD GEN~760 1651 662-1172 299 B LOAD CEa:.800-212 0 0 A 0 A g652 B LOAD GEN.SOUTH BEFORE 1108 BYBT BEFOG AFT" R LOAD GEN.3408 3318 1383 1899 A~After B=Befoze 13 e fa'e Figure 8 GEORGIA eafetre ss (I v I efot I'/sho~ee A W s(OIO Gy Cp AFFECTED OP(etre a r r t te LOSS OF~eet:-'-'-"=...>), ese Iatt C Fe'TP'l'L C slee~I~I apetw<<4 ea Wrac I I I<>4.>u'(MAY 16, 1977 Aee fr'a 8 12:03 PM P AP NKL ANDYTOWN-ORANGE RIVER 500KV LINE~A va'(('.I Jh.~r PC 0~I VVA o aae I~NA>>I~toe ttt I V<<~Ipvea Was~4 AVO(;I', prt~II aa>>~Ies ts~ts>>I I~~Cell~<<I see~~K Asal~<<vs'Oe 1 4 psew 11 I ro ja Sresatot~Os<<I~~I~I OL~1>>ve~<<1<<a(I Iae I~~v 41<<>>I~~Lccae'4~I a~4<<ope I OA II~<>I~(~et~~Ae~e 4<<tree (feces CO reoeeeO CO Ae<<<<N~~e (s[s 1~~IN VI loses~\1 ae I aa sl aa's<<V Aes~~~~w~~~I (aao e~~~'I'I t Set eeet~v Cr(~La(sea ve op II OA(vto~a<<>>4 VALI tl A O~1 ea I p eer'PS'oe Ol I f ea stele OOA re(e I esteo 4'.(IK.)-~g(ep oe~ce I sooCTefee eeo Telesessssoe svstte Cl v~9 view eecv ockce~4;.C irtC~~\~vs"e al ae ve ee avo(oooaf 44OCS 1<<AI~(Fr I 1 (1~~I I~AV e I//ICwsv avl//e<<Is eesveeo co'I Pl Asr pse crea 0 7((, 0 0 calle sl(as~NORTH AREA VVI AL(rpo<<se 4 (1 lF~~~I Cases(4(L eae~I>>~v seal cess 4 Ko~A<<o, av nsv Nee 4<<f~to 4(~~e 1 IA I~I tt~~tlat IA sasv w ra o w~~~swaanf'Mae(ht v<<sree I~V(1>>reste 441>>~sesee Aa(Pace((p lrr e eef~<>v<<e>>veri(WEST~o(al(4 ll(Pt~Ape~a ee(I~Aeo<<<<I ee%title I sspa~O 4 aevi O sas TNSN l(I ION IN SOO ov lao ev I le lv NS ov~4 ev seec ocoosee cleat't h OCO<<C CTess tow(a sssese scevet (44(~esfesscv eet oev (Tsfe+41 terse(fs fa ep I I's STI Lw((IL at~~I~<<A I~Ir\Skl W aaeoswa gPtj'ts I t O aa e'ee 1 ue, (CI S ls OSTI TS cceclefsec OLNn 4<<tape e woawse 4(ecoalae ro<<T OAV feetssoeeafee of Iewseasee voef(et Teeelesssee (serf(TION Tee (eh(co svtsflfee tate Teleltoastlloss ce T~LOSehsee Lo(lect osfeesffscv lue(TOTee I I I ltl Ill I~I ISI cssosho~Ttwsro ec~(teat(Tv~10 ov coo(TOLL(Tee.
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