1539pk

2003 MAJOR POWER GRID 2003 MAJOR POWER GRID BLACKOUTS IN BLACKOUTS IN

NORTH AMERICA AND EUROPENORTH AMERICA AND EUROPE

Copyright © P. KundurThis material should not be used without the author's consent

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August 14, 2003 Blackout of Northeast US August 14, 2003 Blackout of Northeast US and Canadaand Canada

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14 August 2003 Blackout 14 August 2003 Blackout of Northeast US - Canadaof Northeast US - Canada

Approximately 50 million people in 8 states in the US and 2 Canadian provinces affected

63 GW of load interrupted (11% of total load supplied by Eastern North American Interconnected System)

During this disturbance, over 400 transmission lines and 531 generating units at 261 power plants tripped

For details refer to: "Final Report of Aug 14, 2003 Blackout in the US and Canada: Causes and Recommendations", US-Canada Power System Outage Task Force, April 5, 2004. www.NERC.com

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NERC Regions Affected: NERC Regions Affected: MAAC, ECAR, NPCCMAAC, ECAR, NPCC

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Conditions Prior to BlackoutConditions Prior to Blackout

Electricity demand high but not unusually high

Power transfer levels high, but within established limits and previous operating conditions

Planned outages of generating units in the affected area: Cook 2, Davis Bess plant, East Lake 4, Sammis 3 and Monroe 1

Reactive power supply problems in the regions of Indiana and Ohio prior to noon

Operators took actions to boost voltages

voltages within limits

System operating in compliance with NERC operating policies prior to 15:05 Eastern Daylight Time

Aug 14, 2003 US-Canada Blackout

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Blackout Started in MidwestBlackout Started in Midwest

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Sequence of EventsSequence of Events

The Midwest ISO (MISO) state estimator and real-time contingency analysis (RTCA) software not functioning properly from 12:15 to 16:04

prevented MISO from performing proper "early warning" assessments as the events were unfolding

At the First Energy (FE) Control Center, a number of computer software problems occurred on the Energy Management System (EMS) starting at 14:14

contributed to inadequate situation awareness at FE until 15:45

The first significant event was the outage of East Lake generating unit #5 in the FE system at 13:31:34

producing high reactive power output

voltage regulator tripped to manual on overexcitation

unit tripped when operator tried to restore AVR

cont'd

Aug 14, 2003 US-Canada Blackout

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East Lake 5 Trip: 1:31:34 pmEast Lake 5 Trip: 1:31:34 pm

ONTARIO

2

1

ONTARIO

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Initial line trips in Ohio, all due to tree contact:

Chamberlin-Harding 345 kV line at 15:05:41

Hanna-Juniper 345 kV line at 15:32:03

Star-South Canton 345 kV line at 15:41:35

Due to EMS failures at FE and MISO control centers, no proper actions (such as load shedding) taken

Critical event leading to widespread cascading outages in Ohio and beyond was tripping of Sammis-Star 345 kV line at 16:05:57

Zone 3 relay operation due to low voltage and high power flow

Load shedding in northeast Ohio at this stage could have prevented cascading outages that following

Sequence of Events Sequence of Events cont'dcont'd

Aug 14, 2003 US-Canada Blackout

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(3:05:41)(3:32:03)

Star- S. Canton (3:41:35)

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Sammis-Star(4:05:57.5)

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Tripping of many additional 345 kV lines in Ohio and Michigan by Zone 3 (or Zone 2 set similar to Zone 3) relays

Tripping of several generators in Ohio and Michigan

At 16:10:38, due to cascading loss of major lines in Ohio and Michigan, power transfer from Canada (Ontario) to the US on the Michigan border shifted

power started flowing counter clockwise from Pennsylvania through New York and Ontario into Michigan

3700 MW of reverse power flow to serve loads in Michigan and Ohio, which were severed from rest of interconnected system except Ontario

Voltage collapsed due to extremely heavy loadings on transmission lines

Cascading outages of several hundred lines and generators leading to blackout of the region

Sequence of EventsSequence of Events

Aug 14, 2003 US-Canada Blackout

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Power Transfers Shift at 4:10:38.6 pmPower Transfers Shift at 4:10:38.6 pm

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Generator Trips to 16:10:38Generator Trips to 16:10:38

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Generator Trips - Next 7 SecondsGenerator Trips - Next 7 Seconds

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Northeast Completes Separation from Northeast Completes Separation from Eastern InterconnectionEastern Interconnection

4:10:43 - 4:10:45 pm4:10:43 - 4:10:45 pm

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Generator Trips - After 16:10:44Generator Trips - After 16:10:44

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End of CascadeEnd of Cascade

Areas Affected by the BlackoutService maintained

in some area

Some Local Load Interrupted

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Primary Causes of BlackoutPrimary Causes of Blackout(as identified by the US-Canada Outage Task Force)(as identified by the US-Canada Outage Task Force)

1. Inadequate understanding of the power system requirements:

First Energy (FE) failed to conduct rigorous long-term planning studies and sufficient voltage stability analyses of Ohio control area

FE used operational criteria that did not reflect actual system behaviour and needs

ECAR (East Central Area Reliability Council) did not conduct an independent review or analysis of FE's voltage criteria and operating needs

Some NERC planning standards were sufficiently ambiguous that FE could interpret them in a way that resulted in inadequate reliability for system operation

cont'd

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Causes of Blackout Causes of Blackout cont'dcont'd

2. Inadequate level of situation awareness:

FE failed to ensure security of its system after significant unforeseen contingencies

FE lacked procedures to ensure that its operators were continually aware of the functional state of their critical monitoring tools

FE did not have adequate backup tools for system monitoring

3. Inadequate level of vegetation management (tree trimming)

FE failed to adequately manage tree growth into transmission rights-of-way

resulted in the outage of three 345 kV lines and one 138 kV line

cont'd

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Causes of Blackout Causes of Blackout cont'dcont'd

4. Inadequate level of support from the Reliability Coordinator

due to failure of state estimator, MISO did not become aware of FE's system problems early enough

did not provide assistance to FE

MISO and PJM (Regional Transmission operator) did not have in place an adequate level of procedures and guidelines for dealing with security limit violations due to a contingency near their common boundary

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September 23, 2003 Blackout of September 23, 2003 Blackout of Southern Sweden and Eastern DenmarkSouthern Sweden and Eastern Denmark

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The Transmission Grid in The Nordic The Transmission Grid in The Nordic CountriesCountries

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Blackout of 23 September 2003 in Blackout of 23 September 2003 in Southern Sweden and Eastern DenmarkSouthern Sweden and Eastern Denmark

Pre-disturbance conditions:

system moderately loaded

facilities out of services for maintenance:

400 kV lines in South Sweden

4 nuclear units in South Sweden

3 HVDC links to Germany and Poland

The first contingency was loss of a 1200 MW nuclear unit in South Sweden at 12:30 due to problems with steam valves

increase of power transfer from the north

system security still acceptable

Five minutes later (at 12:35) a disconnector damage caused a double busbar fault at a location 300 km away from the first contingency

resulted in loss of a number of lines in the southwestern grid and two 900 MW nuclear units

At 12:37, voltage collapse in the eastern grid section south of Stockholm area

isolated southern Sweden and eastern Denmark system from northern and central grid

cont'd

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The Blackout in Southern Sweden and The Blackout in Southern Sweden and Eastern Denmark, September 23, 2003Eastern Denmark, September 23, 2003

At 12.30: Loss of a 1200 MW Nuclear Unit

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The Blackout in Southern Sweden and The Blackout in Southern Sweden and Eastern Denmark, September 23, 2003Eastern Denmark, September 23, 2003

At 12.35: Double bus-bar fault leading to-Loss of two 900 MW Nuclear Units

-Disrupture of the south-western grid

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The Blackout in Southern Sweden and The Blackout in Southern Sweden and Eastern Denmark, September 23, 2003Eastern Denmark, September 23, 2003

TenhultStrömma

Horred

Söderåsen

Barsebäck

Hemsjö

Simpevarp

Nybro

Kimstad

Glan

Kolstad

Hallsberg

Breared Alvesta

The voltage collapse

Maintenance work

The fault in Horred

Line outages due to:

TenhultStrömma

Horred

Söderåsen

Barsebäck

Hemsjö

Simpevarp

Nybro

Kimstad

Glan

Kolstad

Hallsberg

Breared Alvesta

The voltage collapse

Maintenance work

The fault in Horred

Line outages due to:

The voltage collapse

Maintenance work

The fault in Horred

Line outages due to:

Voltage Collapse

Isolated Subsystem

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The Blackout in Southern Sweden and The Blackout in Southern Sweden and Eastern Denmark, September 23, 2003Eastern Denmark, September 23, 2003

The blacked-out area after the grid separation at 12.37

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The isolated system had enough generation to cover only about 30% of its demand

voltage and frequency collapsed within a few seconds, blacking out the area

Impact of the blackout:

loss of 4700 MW load in south Sweden

1.6 million people affected

City of Malmo and regional airports and rail transportation without power

loss of 1850 MW in eastern Denmark

2.4 million people affected

City of Copenhagen, airport and rail transportation without power

Result of an (n-3) contingency, well beyond "design contingencies"

Blackout of 23 September 2003 in Blackout of 23 September 2003 in Southern Sweden and Eastern Denmark Southern Sweden and Eastern Denmark

cont'dcont'd

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September 28, 2003 Blackout of ItalySeptember 28, 2003 Blackout of Italy

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Italian System Blackout of Italian System Blackout of 28 September 200328 September 2003

Predisturbance conditions (Sunday, 3:00 am):

total load in Italy was 27,700 MW, with 3638 MW pump load

total import from rest of Europe was 6651 MW

Sequence of events:

a tree flashover caused tripping of a major tie-line between Italy and Switzerland (Mettlen-Lavorgo 380 kV line) at 03:01:22

Sychro-check relay prevented automatic and manual reclosure of line due to the large angle (42°) across the breaker

resulted in an overload on a parallel path

attempts to reduce the overload by Swiss transmission operators by network change was not successful

at 03:21 import by Italy was reduced by 300 MW but was not sufficient to mitigate the overload of a second 380 kV line (Sils-Soazza), which tripped at 03:25:22 due to sag and tree contact

cont'd

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the cascading trend continued and the power deficit in Italy was such that the ties to France, Austria and Slovania were tripped

the outages left the Italian system with a power shortage of 6400 MW

the frequency decay could not be controlled adequately by under-frequency load shedding

over the course of several minutes, the entire Italian System collapsed at 3:28:00

The blackout affected about 60 million people

total energy not delivered 180 GWh

worst blackout in the history of Italy

power was restored after 3 hours in the northern area and during the same day for most of Italy

Italian System Blackout of Italian System Blackout of 28 September 2003 28 September 2003 cont'dcont'd