Large Disturbance in the European Power System on the 4th of November 2006

CAMS/RRPA Panel SessionMitigation and Prevention of Cascading Outages:

Methodologies and Practical ApplicationsPES General Meeting, Vancouver, Canada

July 24, 2013

Janusz Bialek (Durham), Vladimir Terzija (Manchester), Taiying Zheng (Manchester), Walter Sattinger (Swissgrid)

janusz.bialek@durham.ac.uk

• Site of two UNESCO Wold Heritage Sites

• 3rd oldest university in England

Durham University

PMAPS 2014, Durham

• International Conference on Probabilistic Methods Applied to Power Systems, 7-10 July 2014

• Paper submission deadline 30 Nov 2013• www.dur.ac.uk/pmaps.2014, pmaps.admin@durham.ac.uk

• Source of data and diagrams: UCTE “Final Report System Disturbance on 4 November 2006”

• 15M households affected, 16,724 MW lost• The worst disturbance in 50 years of UCTE/ENTSOE in terms

of the number of TSOs affected and frequency deviations involved

• Duration 1 hour and 35 minutes (22:10-23:45) but only 38 minutes three island operation

• East-West transfer• 15 GW of wind (5.5%)• High flows around

Germany

Source: UCTE

Voltage phase angle differences in the UCTE system at 22:00

Source: UCTE Abschlussbericht zur Systemstörung 4. Nov. 2006

Loading pre-disturbance

• Note the difference between scheduled and actual flows (e.g. FR-D, FR-BE) due to loop flow phenomenon

• Especially important D-NL, D-PL due to high wind

Source: UCTE

Timeline

• 18 Sept: a shipyard request EON for a routine disconnection of double circuit 380 kV line in Northern Germany on 5 Nov

• 3 Nov: the shipyard request to bring forward the disconnection by 3 hours

• EON agrees provisionally but does not modify Day Ahead Congestion Forecast (DACF) distributed to all TSOs

• 4 Nov, 7 pm: EON informs RWE and TenneT about new time for the line outage

• 9.30 pm: EON concludes empirically, without updated (N-1) analysis, that the outage would be secure (it wasn’t!)

Image: http://www.cruise-ship-report.com/News/110506.htm

• RWE does (N-1) analysis of its area which indicates high but secure loading

• 9.38: EON disconnects the line • 9.39-41: warnings of high flows• EON assesses the situation empirically, without

simulations, and decides to couple a busbar to reduce the current by 80 A

• Result: the current increases by 67 A and the line trips• Cascading line tripping all over UCTE and separation into

3 regions with different frequencies

Source: UCTE

0.8 GW deficit49.7 Hz

8.9 GW deficit49 Hz

10 GW surplus51.4 Hz

Source: UCTE

Western Europe: 8.9 GW deficit

• Drop of frequency halted by load shedding• But frequency drop caused tripping of 10.7 GW of

generation (40% wind)

North-Eastern Europe: 10 GW surplus

• Initial rise of frequency halted by AGC and tripping of frequency-sensitive generation (mainly wind)

• As frequency started to drop, windmills started to reconnect automatically worsening the situation

• Situation stabilised by manual action of TSOs

Source: UCTE

South-Eastern Europe: modest 0.8 GW deficit

• No load shedding activated, subsystem (N-1) secure

Source: UCTE

Resynchronisation

• A number of uncoordinated unsuccessful attempts made without knowledge of the overall UCTE situation

• Full resynchronisation after 38 minutesSource: UCTE

UCTE root cause analysis

• Main points:– (N-1) security rule, inadequate inter-TSO

coordination– Lack of situational awareness– Other factors (wind farms, lack of coordination)

Improvements since 2006: situational awareness

• Web-based visibility of cross-border flows in Europe, ACE, generation

• traffic light system to indicate security, control reserves and state of IT infrastructure

• RAAS – real-time awareness and alarming system, EAS (ENTSO-E awareness)– all TSOs have the same view – the information maintenance is done on two central points

with highly redundant infrastructure.

Improvements since 2006: coordinated (N-1) security analysis

• All national files are merged into one common CE load flow file

• each TSO downloads the complete system and perform complete (n-1) calculation.

• Evening phone/web/video conference of all the TSOs to coordinate remedial actions

Further Measures: Synchronized Measurement Technology, WAMS

WAMS

HSE/PMU-SE

Situational Awareness

Dynamic SecurityAssessment

Decision Making

All measurements are synchronised by GPS signal

48.8

49

49.2

49.4

49.6

49.8

50

50.2

50.4

50.6

50.8

51

51.2

51.4

51.6

04.11.2006 22:00:00 04.11.2006 22:10:00 04.11.2006 22:20:00 04.11.2006 22:30:00 04.11.2006 22:40:00 04.11.2006 22:50:00 04.11.2006 23:00:00

f [H

z]

frequency Bassecourt frequency Ag. Stefanos frequency Ternitz

Data Records during 39 Minutes of the Islanding System Operation

Source: W.Sattinger, Swissgrid

Large Disturbance in the European Power System on the 4th of November 2006

CAMS/RRPA Panel SessionMitigation and Prevention of Cascading Outages:

Methodologies and Practical ApplicationsPES General Meeting, Vancouver, Canada

July 24, 2013

Janusz Bialek (Durham), Vladimir Terzija (Manchester), Taiying Zheng (Manchester), Walter Sattinger (Swissgrid)

janusz.bialek@durham.ac.uk