2003 major power grid blackouts in north america and europe august 14, 2003 Blackout of Northeast us and Canada

2003 MAJOR POWER GRID BLACKOUTS IN NORTH AMERICA AND EUROPE

August 14, 2003 Blackout of Northeast US and Canada

14 August 2003 Blackout of 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

NERC Regions Affected: MAAC, ECAR, NPCC

Conditions 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

Blackout Started in Midwest

Sequence 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

East Lake 5 Trip: 1:31:34 pm

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

• 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

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 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

Power Transfers Shift at 4:10:38.6 pm

Generator Trips to 16:10:38

Generator Trips - Next 7 Seconds

Northeast Completes Separation from Eastern Interconnection 4:10:43 - 4:10:45 pm

Generator Trips - After 16:10:44

End of Cascade

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

• 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

Causes of Blackout cont'd

• 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

• 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

Causes of Blackout cont'd

• 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

September 23, 2003 Blackout of Southern Sweden and Eastern Denmark

The Transmission Grid in The Nordic Countries

Blackout of 23 September 2003 in Southern 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

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

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

Blackout of 23 September 2003 in Southern Sweden and Eastern Denmark cont'd

• 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"

September 28, 2003 Blackout of Italy

Italian System Blackout of 28 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

Italian System Blackout of 28 September 2003 cont'd

• 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