SEVENTH FRAMEWORK PROGRAMME
THEME [ENERGY.2011.7.3-1]
[Innovative tools for the future coordinated and stable
operation of the pan-European electricity transmission
system]
Project Deliverable
Deliverable D 7.3 “Workshop results on innovative
operational tools”
Project acronym:
UMBRELLA
Project full title:
Toolbox for Common Forecasting, Risk
assessment, and Operational Optimisation
in Grid Security Cooperations of
Transmission System Operators (TSOs)
Grant
agreement
no.:
282775-2
Contents
1 JOINT COOPERATION BETWEEN ITESLA AND UMBRELLA ... 3
2 ORGANIZATION AND STRUCTURE OF COMMON WORKSHOP ... 4
3 SUMMARY OF THE WORKSHOP PRESENTATIONS ... 7
3.1 Morning Session: iTesla ... 7
3.1.1 Overview ... 7
3.1.2 General Architecture of the Security Assessment Process ... 7
3.1.3 Definition of Security Rules Taking into Account Uncertainties and System Dynamics ... 8
3.1.4 Demo of Prototype Modules ... 8
3.1.5 Validation of Dynamic Models and Use of Modelica Models ... 9
3.1.6 Defense Plan and Restoration ... 9
3.2 Afternoon Session: UMBRELLA ... 10
3.2.1 Overview ... 10
3.2.2 Modelling uncertainties relevant for the operation of the European transmission grid ... 10
3.2.3 Optimization algorithms for transmission system operation ... 11
3.2.4 Risk-based Security Assessment incorporation Forecast Uncertainty and Cascading events ... 12
3.2.5 Toolbox Requirements based on TSO Demands and Testing Environment ... 13
4 UMBRELLA WORKSHOP PRESENTATIONS ... 15
4.1 Overview on and state of the Umbrella project ... 15
4.2 Modeling uncertainties relevant for the operation of the European trans. grid ... 29
4.3 Optimization algorithms for transmission system operation ... 42
4.4 Risk-based Security Assessment: Incorporating Forecast Uncertainty and Cascading Events ... 52
1 Joint Cooperation between iTesla and UMBRELLA
A description of the joint-collaboration between iTesla and UMBRELLA can be found in deliverable D7.2, which can be downloaded from the website www.e-UMBRELLA .eu. The two projects aligned their starting date and duration to facilitate collaboration. A memorandum of understanding was established and agreed before signing the present Grant Agreements in order to outline the framework of the future detailed work foreseen by the consortiums.
As mentioned in D7.2, the cooperation of the two projects includes the following cornerstones:
Three common workshops will be organized by iTesla and UMBRELLA :
o Workshop on innovative tools needed for the future and stable system operation (M6) to exchange information about respective project objectives, dissemination, key drivers, results of previous studies (knowledge sharing and information exchange)
o Workshop on intermediate results (M25) (exchange and present information about intermediate results and deliverables)
o Workshop on final results (M46) (exchange and present information about final results).
A common-use case on which both approaches will be validated.
A detailed description of necessary information exchange and knowledge sharing was elaborated in deliverable D1.1.“iTesla Cooperation”.
A common deliverable dealing with common recommendations to ENTSO-E regarding operating rules (for iTesla, Deliverable D8.4 – for UMBRELLA D6.2 - Delivery date M46) will be elaborated.
In the present deliverable, the results of the second common ‘Workshop on intermediate results’, co-organized by UMBRELLA and iTesla projects are summarized. The workshop was hosted at ENTSO-E’s premises on January 14th, 2014 with a total number of some 80 registered participants including experts from industry, academia and regulatory bodies.
This deliverable is structured in the following way: Chapter 1 introduces the framework for joint-collaboration, Chapter 2 presents the organization and structure of common workshop, Chapter 3 presents a summary of the workshop presentations and in Chapter 4 the presentation slides from the UMBRELLA Project are displayed.
All presentations and related documents are available for download at www.e-UMBRELLA.eu , as approved by all presenters.
2 Organization and structure of common workshop
The common workshop, co-organized by the UMBRELLA and iTesla projects, was held at ENTSO-E’s premises in Brussels on January 14th, 2014. Most of the stakeholders were invited by email. Moreover, the UMBRELLA consortium published a newsletter during the middle of December. This newsletter contained information about the workshop and about the way to subscribe. In this occasion, the subscription and logistic organization of this event was carried out mainly by iTesla.
The agenda of the workshop consisted of the following parts:
10:00 Workshop opening
Welcome speech Dr. Chavdar Ivanov – ENTSO-E
10:15 iTesla Toolbox
Overview on and state of the iTesla project
General architecture of the security assessment process
Definition of security rules taking into account uncertainties and system dynamics
Coffee break (15 minutes)
Demo of prototype modules
Validation of dynamic models and use of Modelica models
Defense plan and restoration
Christian Lemaître Jean-Baptiste Heyberger, Diego Cirio Ioannis Konstantelos, Philippe Duchesne Geoffroy Jamgotchian, Massimo Ferraro Luigi Vanfretti Poul Sørensen, Regina Llopis Rivas
13:00 Lunch
14:00 Umbrella Toolbox
Overview on and state of the Umbrella project
Modeling uncertainties relevant for the operation of the European transmission grid
Optimization algorithms for transmission system operation
Coffee break (15 minutes)
Risk-based Security Assessment incorporating Forecast Uncertainty and Cascading Events
Toolbox Requirements based on TSO Demands and Testing Environment
Dr. Wulf A. Engl, Helmut Paeschke,
Dr.ir. Laura Ramírez-Elizondo Raik Becker,
Prof. Christoph Weber Jonas Eickmann, Tobias van Leeuwen
Thilo Krause, Frauke Oldewurtel, Line Roald
Peter Gilsdorf, Dr. Simon Krahl, Michael Rogge, Oliver Scheufeld
The opening was carried out by Dr. Chavdar Ivanov, Research and Development Senior Advisor of ENTSO-E. He introduced the ENTSO-E R&D Roadmap and the R&D Implementation Plan. Furthermore, he referred to the importance of the work and deliverables of both the iTesla and the UMBRELLA projects.
The morning session was focused on the iTesla toolbox. Several researchers of the project gave detailed presentations of their progress. In Chapter 3, a summary of these presentations is provided. On the other hand, the afternoon session was dedicated to the Umbrella toolbox. The respective researchers provided comprehensive presentations about the progress of the different work packages. In both cases, the sessions started with an overview of the respective project. This allowed the stakeholders and new participants to obtain a general idea about the main research focus and the main goals.
3 Summary of the workshop presentations
3.1
Morning Session: iTesla
3.1.1 Overview
The main objective of the iTesla project is to develop a toolbox that will be needed by
Transmission System Operators to operate the European power system in the years to come. Particularly the iTesla toolbox will provide operators with tools to assess the security
of power system situations from 2 days ahead to real time. As part of the project, validation of the toolbox with different European grids in various situations will be performed.
The three main challenges to be tackled in the project are the following:
To model the increasing amount of uncertainties in the decision process To take into account system dynamics in the security assessment To model preventive actions and take them in the decision process 3.1.2 General Architecture of the Security Assessment Process
In this presentation the proposed architecture to target uncertainties, dynamics and action recommendation was explained. First, the existing architecture was shown and later this architecture was upgraded with dynamic simulations, the inclusion of uncertainties and with the addition of a filtering process. The proposed final architecture is presented in Figure 3:
Figure 3 Proposed Final Architecture
New online security assessment
3.1.3 Definition of Security Rules Taking into Account Uncertainties and System Dynamics
This presentation started by introducing the offline security rules. Later, the sampling process to be used within the iTesla architecture was explained. It was indicated that uncertainties expand the possible operating point state‐space.
The presentation gave particular attention to historical data. The presenters argued that historical data contain information on what the TSO should anticipate in the near future. In their approach, all resulting operating points are analysed using dynamic simulation tools. Furthermore, steady‐state and dynamic indices have been developed to classify pre‐fault state‐space with respect to post‐fault performance.
Finally, it was stated that machine learning enables to ‘compress’ information of 100,000s dynamic simulations into robust security rules.
3.1.4 Demo of Prototype Modules
In this presentation the data manager, the computation manager and the workflow manager were explained by means of diagrams. For example, the diagram of the workflow manager is depicted in Figure 4:
3.1.5 Validation of Dynamic Models and Use of Modelica Models
This presentation contained information about how to make and use models of the Modelica software and about how to perform model validation. Different validation levels were identified: component level, cluster level and system level. One of the representative slides corresponds to a diagram containing the offline validation of dynamic models. This diagram is depicted in Figure 5:
Figure 5 Offline Validation of Dynamic Models
3.1.6 Defense Plan and Restoration
This presentation focused on the development of a workplan for defense and restoration. With regard to the defense plan, the speakers referred to the following aspects:
Detection of weak points in existing plans Use of renewable generation plants Pan‐European coordination
Use of PMUs
Use of distributed energy resources
With respect to restoration, the aspects that were considered are:
Coordinated restoration (AIA)
3.2
Afternoon Session: UMBRELLA
3.2.1 Overview
The main objective of the UMBRELLA project is to develop an innovative toolbox to support the decentralised grid security approach of TSOs. This toolbox shall include:
the simulation of uncertainties due to market activities and renewables on different time scales
the optimisation of corrective actions in reaction to simulated risks on different time scales according to total costs and transmission capacities
the development of risk based assessment concepts for anticipated system states with and without corrective actions.
Moreover, the projects aims at demonstrating the enhancement of existing and running procedures by utilisation of the developed toolbox and providing a scientifically sound basis to support common TSO decisions.
3.2.2 Modelling uncertainties relevant for the operation of the European transmission grid
This presentation focused on the second work package of the UMBRELLA project. This work package aims at developing a set of methods to describe the key developments influencing the future state of the European electricity grid. This is done through the accomplishment of five tasks, as depicted below. Each of the tasks was described during the presentation.
Figure 5 Separation and Re-aggregation of Uncertainties
At the end of the presentation, the following next steps were presented:
Finalizing solar power uncertainty for D and CZ
Finalizing wind power uncertainty for D, PL, NL and AT Finalizing power plant outages for all participants Finalizing load uncertainty for all participants Make test interface for following tasks Aggregating all uncertainties
3.2.3 Optimization algorithms for transmission system operation
This presentation focused on Work Package 3. The objective of this work package is to develop an expert system that is capable of assisting the transmission system operators during the congestion management process. The presentation started by introducing the main challenges, followed by the preliminary results and the outlook. Figure 6 shows an overview of the optimization methods:
The main conclusions are enumerated below:
The developed algorithms promise to be capable of providing valuable input to system operators by suggesting appropriate and secure remedial measures All required optimization steps can be carried out in day ahead time horizon and
even assist the operators in real-time
Further work will enable the consideration of uncertainties in the operational planning processes
Figure 6 Overview of the optimization mehtods
o Step 1: Optimization algorithms supporting operational planning process o Step 2: Short term optimization methods for realtime grid operation o Step 3: Optimized uncertainty accounting in operational planning
Results Input data
Grid topology Uncertainty
Dispatch incl. RES
Congestions Available remedial measures Optimal combination of remedial measures
State of the art Step 1 Step 2 Step 3 Enhanced Optimal Power
Flow Uncertainty
Intra Day Congestion Forecast (Real time restrictions)
Day ahead Congestion Forecast
3.2.4 Risk-based Security Assessment incorporation Forecast Uncertainty and Cascading events
In this presentation, the method for risk-based security assessment that is followed in the UMBRELLA project was described. The method includes ways to assess how cascading events, different market design/cooperation rules between TSOs and state-of-the-art technological measures as e.g. FACTS (Flexible Alternating Current Transmission Systems) and PSTs (Phase-shifting Transformers) may influence the overall system risk. The diagram below provides an overview of the method:
Figure 7 Overview of the Risk-based security assessment method
At the end of the presentation, the following key messages were given:
System security has a cost!
o Increased uncertainty due to RES in-feeds and short-term trading leads to higher cost
Risk-based methods for system security o Utilize additional information o Account for RES uncertainty
o Account for available flexibility (PSTs, remedial actions) o Account for cascading events
o Provide a quantitative assessment of system security level Better trade-off between operation cost and system risk!
3.2.5 Toolbox Requirements based on TSO Demands and Testing Environment
This was the last section of the workshop. It comprised two work packages. The overview scheme and the key messages or each work package are included below.
Work Package 5
Figure 8 Overview of Work Package 5
The key messages were:
Distinction between functional and data requirements o Different functionalities require specific input data
Data provision and exchange between functionalities (i.e. WPs) is major challenge and key success factor
o Intensive communication and meetings with forecasting, optimization and risk-based-assessment set up
Specification of data characteristics (format, granularity etc.) to be provided o Research work still in progress
Work Package 6
Figure 9 Overview of Work Package 6
The key messages were:
Demonstrating and testing is still in an early stage
Even in this early stage further European harmonization seems preferable, especially regarding data definitions, data formats and data handling.
Acknowledgement
The UMBRELLA consortium would like to thank ENTSO-E for hosting the workshop and the organizational work as well iTesla for the very good cooperation.
4 UMBRELLA Workshop presentations
Overview on and state of the Umbrella project 1 Brussels, 14/01/14
Innovative Tools for the Future Coordinated Operation of the
Pan-European Electricity Transmission System
Overview on and state of the Umbrella project
Helmut Paeschke, Dr. Wulf Engl TenneT TSO GmbH
Laura Ramirez - Elizondo Delft University of Technology
2nd iTesla/Umbrella Open Workshop, Brussels, 14-01-2014
Overview on and state of the Umbrella project 2 Brussels, 14/01/14
Overview on and state of the Umbrella
project
I.
Project Objectives
II.
Project Participants
III.
Project Structure
IV. Present situation and Challenges
V.
Dissemination and Website
Overview on and state of the Umbrella project 3 Brussels, 14/01/14
◦
Develop an innovative toolbox to support the decentralised grid
security approach of TSOs. This toolbox shall include
simulation of uncertainties due to market activities and
renewables on different time scales
optimisation of corrective actions in reaction to simulated risks
on different time scales according to total costs and
transmission capacities.
development of risk based assessment concepts for anticipated
system states with and without corrective actions
◦
Demonstrate the enhancement of existing and running procedures
by utilisation of the developed toolbox
◦
Provide a scientifically sound basis to support common TSO
decisions.
Main Objectives of UMBRELLA
Overview on and state of the Umbrella project 4 Brussels, 14/01/14
Overview on and state of the Umbrella
project
I.
Project Objectives
II.
Project Participants
III.
Project Structure
IV. Present situation and Challenges
V.
Dissemination and Website
Overview on and state of the Umbrella project 5 Brussels, 14/01/14
Project Participants
Overview on and state of the Umbrella project 6 Brussels, 14/01/14Project Participants
Participant legal name Country Organisation
TenneT TSO GmbH (Coordinator) Germany TSO
Amprion GmbH Germany TSO
ČEPS, a.s. Czech Republic TSO
Elektro-Slovenija, d.o.o Slovenia TSO
TransnetBW Germany TSO
PSE Operator S.A. Poland TSO
swissgrid ag Switzerland TSO
TenneT TSO B.V. Netherlands TSO
Austrian Power Grid AG Austria TSO Delft University of Technology Netherlands University
ETH Zurich Switzerland University
Graz University of Technology Austria University
RWTH Aachen Germany University
University Duisburg-Essen Germany University
Overview on and state of the Umbrella project 7 Brussels, 14/01/14
Overview on and state of the Umbrella
project
I.
Project Objectives
II.
Project Participants
III. Project Structure
IV. Present situation and Challenges
V.
Dissemination and Website
VI. Publications
Overview on and state of the Umbrella project 8 Brussels, 14/01/14Project structure
Risk‐based Assessment OptimizationForecasting Synthesis and
Prototyping
PM Project Management (WP1)
PMB
Project
Management
Board
WP2
WP3
WP4
WP5
General project organisation: Common structure from the working to the steering level
Demonstration and Testing
WP6
DisseminationWP7
Project Consortium
U Duisburg‐Essen RWTH Aachen ETH Zurich Amprion TransnetBW TU Delft
TenneT TSO Germany
PMT Project Management Team
(PM, WG-Leaders)
Overview on and state of the Umbrella project 9 Brussels, 14/01/14
Overview on and state of the Umbrella
project
I.
Project Objectives
II.
Project Participants
III.
Project Structure
IV. Present situation and Challenges
V.
Dissemination and Website
VI. Publications
Overview on and state of the Umbrella project 10 Brussels, 14/01/14
Present Situation
o
In the mainland Europe synchronous area substantial difference
between
- actual physical flows and
- the market exchanges
Problems due to “loop” flows already today
o
Analysis of the 2015 time horizon identified
o
Increasing power transits due to market activities
o
Higher power flows from large wind power installations
(Germany) directed to remote load centres than
- previous national studies had anticipated
- existing planned reinforcements can accommodate
o
Increasing “loop” flows through Poland and the Czech Republic
Overview on and state of the Umbrella project 11 Brussels, 14/01/14
Operational challenges in Central Europe
Challenges concerning system operation with a significant contribution from RES relate to: • Coordination of the operation of flow controlling devices across Europe and
• of system arrangements to adjust power flows in the event of faults and other events. • Development and use of dynamic equipment ratings reflecting ambient conditions, loading
and conductor temperatures.
•Shared intelligence on developing generation and load conditions (including wind forecasts). •Suitable monitoring and control facilities.
• Procedures for using enhanced operational measures to achieve maximum benefit across each region.
Overview on and state of the Umbrella project 12 Brussels, 14/01/14
◦
Increasing uncertainties due to
- growing share of electricity generation from intermittent RES
- as well as increasing market-based cross border flows
◦
Enhanced grid capability and grid flexibility
◦
New possibilities in network operation due to
- new planned interconnections including new technologies (AC, DC),
- devices for power flow control and FACTS for system services
◦
Better system coordination and cooperation by using common tools
Further developments of common grid security tools are therefore one
of the major challenges European TSOs will face in the mid-term.
Coping with these challenging system security research issues the
toolbox to be developed will enable TSOs to ensure secure grid
operation also in future electricity networks with high penetration of
intermittent renewables.
Overview on and state of the Umbrella project 13 Brussels, 14/01/14
Make Use of Hybrid Grid Solutions
… new transmission for new energy
sources …
o
Development of the German
transmission grid for the further
integration of renewables
o
Corridors for the efficient transport of
generated energy from turbines to
consumers
o
Intermediate grid enforcement
measures
o
Sustainable and secure long term grid
solutions for more grid flexibility
(AC/DC systems)
Example Germany…
Overview on and state of the Umbrella project 14 Brussels, 14/01/14
Thank you very much for your attention!
www.e-umbrella.eu
This research work has been carried out within the scope of the project UMBRELLA, supported under the 7th Framework Programme of the European Union, grant agreement 282775.
Questions?
Comments?
Helmut Paeschke Operational Planning and Regional Coordination TenneT TSO GmbH Rosswachtstr. 40 85221 Dachau Telefon: +49 (8131) 3323 ‐ 2902 Telefax: +49 (8131) 3323 ‐ 2503 mailto: helmut.paeschke@tennet.eu www.tennet.eu Dr. Wulf A. Engl Interim and project management Engineering consultant Engl‐Energie Thingstr. 24 D‐82041 Oberhaching Telefon: +49 (89) 905470 ‐ 90 Telefax: +49 (89) 905470 ‐ 88 mailto: info@engl‐energie.de wulf.engl@tennet.eu www.engl‐energie.deBrussels, 21/10/13 15
Overview on and state of the Umbrella
project
I.
Project Objectives
II.
Project Participants
III.
Project Structure
IV. Present situation and Challenges
V.
Dissemination and Website
VI. Publications
Brussels, 21/10/13 16
Main Objective
o
The main objective is to ensure that this project and its results are
brought to the attention of those parties for which this project and its
results are of interest.
Dr. Laura Ramírez‐Elizondo Assistant Professor Electrical Sustainable Energy Department Delft University of Technology Mekelweg 4, NL‐2628 CD Delft Phone: +31 (1) 5278 1848 Telefax: +31 (1) 5278 1182 Mobile: +31 (6) 5097 4304 mailto: L.M.RamirezElizondo@tudelft.nl www.tudelft.nl
Contact
Brussels, 21/10/13 17
Kick-off Meeting
o
Kick-off Meeting was held in Cologne in February 2012.
UMBRELLA Kick-off Meeting
Brussels, 21/10/13 18
Project Website
Brussels, 21/10/13 19
Project Logo
o
The design concepts for the logo were the following:
o
The shining star in the centre: a source of energy and
electricity
o
The pentagonal star: references the stars in the European
Union logo and the European collaboration in the
UMBRELLA project.
o
Coloured arrows which point to the centre of the star from
all directions: the stakeholders involved
o
The total sum of the logo: an UMBRELLA viewed from the
top.
o
A European (Swiss) font was used for the typography:
Helvetica Neue 75 Bold and Helvetica Neue 55 Roman.
Brussels, 21/10/13 20
Brussels, 21/10/13 21
Overview on and state of the Umbrella
project
I.
Project Objectives
II.
Project Participants
III.
Project Structure
IV. Present situation and Challenges
V.
Dissemination and Website
VI. Contacts and Publications
Brussels, 21/10/13 22
Publications (1)
[1]
UMBRELLA WP2, "Deliverable 2.1 ‐ Report on uncertainty modeling,"
http://www.e
‐umbrella.eu/documents, 2013.
[2]
R. Becker and C. Weber, "Using Time‐Adaptive Probabilistic Forecasts for Grid
Management
‐ Challenges and Opportunities," in 31st USAEE/IAEE North
American
Conference, Austin, Texas, USA, 06.11.2012.
[3]
R. Becker and C. Weber, "Probabilistic Wind Power Forecasting in Transmission
Grids
‐ Making use of Spatial Correlation," in WIPFOR: 2nd Workshop on Industry
&
Practices for Forecasting, Paris, France, 06.06.2013.
[4]
M. Schoeneberger, P. Schäfer, O. Scheufeld, S. Krahl and A. Moser, "Forecast of
vertical
reactive loads considering the influence of renewable energy sources
using
artificial neural networks," in Submitted to PSCC, Wroclaw, Poland, 2014.
[5]
UMBRELLA WP3, "Deliverable 3.1 ‐ Report on deterministic algorithms for EOPF,"
http://www.e
‐umbrella.eu/documents, 2013.
[6]
K. Vandyshev, D. Gijswijt and K. Aardal, "Topology Optimization Methods in
Electric
Power Systems," in EURO2013: 26th European Conference on Operational
Research,
Rome, Italy, 1‐4 July, 2013.
Brussels, 21/10/13 23
Publications (2)
[7]
J. Eickmann, C. Pasch, N. Rotering and A. Moser, "Including Reasoning in
Congestion
Management Expert Systems," in submitted to CIGRE conference,
Brussels,
Belgium, 2014.
[8]
UMBRELLA WP4, "Deliverable 4.1 ‐ Risk‐based Assessment Concepts for System
Security
– State‐of‐the‐art review and concept extensions," http://www.e‐
umbrella.eu/documents,
2012.
[9]
L. Roald, F. Oldewurtel, T. Krause and G. Andersson, "Analytical reformulation of
security
constrained optimal power flow with probabilistic constraints," in IEEE
PowerTech,
Grenoble, France, 2013.
[10]
UMBRELLA WP4, "Deliverable 4.2 ‐ Risk assessment methods," http://www.e‐
umbrella.eu/documents,
2013.
[11]
Vrakopoulou, M. and et al., "A Unified Analysis of Security‐Constrained OPF
Formulations
Considering Uncertainty, Risk, and Controllability in Single and
Multi
‐area Systems," in IREP Conference, Crete, Greece, 2013.
Brussels, 21/10/13 24Publications (3)
[12]
L. Roald, M. Vrakopoulou and F. Oldewurtel, "Risk‐Constrained Optimal Power
Flow
with Probabilistic Guarantees," in submitted to PSCC, Wroclaw, Poland,
2014.
[13]
L. Roald, B. Li, F. Oldewurtel, T. Krause and G. Andersson, "An optimal power flow
(OPF)
formulation including risk of cascading events," in submitted to XIII SEPOPE,
Foz du
Iguazu, Brazil, 2014.
[14]
M. d. Jong, G. Papaefthymiou, D. Lahaye, C. Vuik and L. v. d. Sluis, "Impact of
correlated
infeeds on risk‐based power system security assessment," in
submitted
to PSCC, Wroclaw, Poland, 2014.
[15]
K. Köck and H. S. J. Renner, "Probabilistic Cascading Event Risk Management," in
submitted
to PSCC, Wroclaw, Poland, 2014.
[16]
UMBRELLA WP7, "Deliverable 7.1 ‐ Website, basic communication plan and
dissemination
strategy," 2012.
[17]
UMBRELLA WP7, "Deliverable 7.2 ‐ Workshop results on innovative operational
tools,"
2012.
Brussels, 21/10/13 25
Publications (4)
[18]
K. Maslo, "Power system dynamics modelling," in 10th International conference
control
of power systems, Tatranské Matliare Slovak Republic, May 2012.
[19]
Liu, Z. et al., "Challenges Experiences and Possible Solutions in Transmission
System
Operation with Large Wind Integration," in 11th International Workshop
on
Large‐Scale Integration of Wind Power into Power Systems, Lisbon, Portugal,
November
2012.
[20]
Liu, Z. et al., "Innovative operational security tools for the development of a
stable
pan‐European grid," in Cigré Canada, Montreal, Canada, September 2012.
[21]
UMBRELLA WP7, "Deliverable 7.3: Open Workshop on intermediate results
together
with iTesla," 2014.
4.2
Modeling uncertainties relevant for the operation of the European
transmission grid
Overview on and state of the Umbrella project 1 Brussels, 14/01/14
Innovative Tools for the Future Coordinated Operation of the Pan-European Electricity Transmission System
Modeling uncertainties relevant for the
operation of the European transmission grid
Klaus Köck (TUG), Raik Becker (UDE), Christoph Weber (UDE)
2nd iTesla/Umbrella Open Workshop, Brussels, 14-01-2014
Modeling uncertainties relevant for the operation of the European transmission grid 2 Brussels, 14/01/14
Modeling
uncertainties relevant for the
operation
of the European transmission grid
I.
Overview
II.
Feed
‐ins from renewable energy sources
III.
Load
uncertainty
IV.
Intraday trading
V.
Power
plant outages
VI.
Combination
of uncertainties and provision of overall system
states
Modeling uncertainties relevant for the operation of the European transmission grid 3 Brussels, 14/01/14
OVERVIEW
Modeling uncertainties relevant for the operation of the European transmission grid 4 Brussels, 14/01/14Considered
uncertainties in the Umbrella project
1. Feed
‐ins from renewable energy sources
–
Status
quo: only strongly aggregated point predictions
2. Load
–
Status
quo: only point predictions in DACF
3. Intraday
trading
–
Status
quo: no forecasts so far
4. Power
plant outages
–
Status
quo: forecast improvement desirable
Main
objective
Developing a set of methods describing the
key
developments/uncertainties influencing the future state of
the
electricity grid
Modeling uncertainties relevant for the operation of the European transmission grid 5 Brussels, 14/01/14
Main
challenge
•
Most
of the mentioned processes are more or less easy to predict individually
•
However,
TSOs have limited information on the detail of these processes, but can
only
observe an aggregation of them
Collection and use of data becomes difficult
Modeling uncertainties relevant for the operation of the European transmission grid 6 Brussels, 14/01/14Separation
and re‐aggregation of uncertainties
Task
1
Wind and solar powerTask
2
Short‐term tradingTask
3
Load and power plant outages Distribution of nodal in‐feeds and loadTask
4
Deriving forecast distributions for the system stateTask
5
Forecast of critical system statesMust
be
regarded
separately
from
the
vertical
grid
load
Market
interaction
has
to be
considered
Input
for
load
flow
calculations
Early
anticipation
of
critical
system
states
Modeling uncertainties relevant for the operation of the European transmission grid 7 Brussels, 14/01/14
FEED
‐INS FROM RENEWABLE
ENERGY
SOURCES
Modeling uncertainties relevant for the operation of the European transmission grid 8 Brussels, 14/01/14Feed
‐ins from renewable energy sources
Objective
•
Identify
appropriate possibilities for describing these uncertainties in a
way
that grid operators may make use of the information most efficiently
Methodical
key aspects
•
Estimation
of forecast uncertainty
– Conditional probability density function (cpdf) of the forecast error
conditional
on the deterministic forecast
– Different estimation for each grid node and look‐ahead time using non‐
parametric
approaches (Nadaraya‐Watson estimator)
•
Modelling of spatial interdependences
– Gaussian copula models
•
Simulation
of forecast uncertainty
– cpdf + point forecast + copula Monte‐Carlo‐Simulation
Modeling uncertainties relevant for the operation of the European transmission grid 9 Brussels, 14/01/14
Feed
‐ins from renewable energy sources
Periodical
estimation
Daily
operation
Historic
point
measurements
Historic
point
forecasts
Assignment
to grid nodes
Estimate
conditional
probability
density
function
using
CKDE
Estimate
copula
in order
to
model
spatial
inter‐
dependences
Daily
point
forecast
Monte
‐Carlo‐
Simulation
Simulated
distributions
for
each grid
node
In‐ or output Interfaces MethodsAssignment
to grid nodes
Modeling uncertainties relevant for the operation of the European transmission grid 10 Brussels, 14/01/14LOAD
UNCERTAINTY
Modeling uncertainties relevant for the operation of the European transmission grid 11 Brussels, 14/01/14
Load
uncertainty
Objective
•
Identification
of suitable descriptions of the associated uncertainties in view of
providing
a consistent overall system state description
Methodology
•
Identification of
pure load nodes (underlying generation is negligible)
•
Estimation
of the uncertainty using a parametric approach
•
Application
to other nodes
•
Simulation
of the forecast error distributions using Gaussian copulas
Data
•
Load
data from the DACF and SN files
Current
status
•
Load:
completed
, , , , , , Modeling uncertainties relevant for the operation of the European transmission grid 12 Brussels, 14/01/14Load
uncertainty
Exemplary
results for one TSO
Source: Deliverable D2.1 “Report on uncertainty modeling”Modeling uncertainties relevant for the operation of the European transmission grid 13 Brussels, 14/01/14
INTRADAY
TRADING
Modeling uncertainties relevant for the operation of the European transmission grid 14 Brussels, 14/01/14Integrating
uncertainty in short‐term trading
Objective
•
Detailed
analysis of intraday renominations and a subsequent proposal for
statistical
description
Methodology
•
Prediction
of changes in power in‐feed at grid node level by using a merit‐
order
model
Data
•
DACF
in order to derive power plant schedules
•
Fuel
prices
•
Uncertainties
of RES, load and power plant outages
Current
status
•
Implementations
in MATLAB completed, results from wind and solar
power
uncertainty modelling are required for final evaluation
Modeling uncertainties relevant for the operation of the European transmission grid 15 Brussels, 14/01/14
Range
of future short‐term trading
Price Quantity E(PWind) Demand Price by expected wind in‐feedsInput
, , … ,
Output
Δ
Uncertainty of wind power etc. Change in power production at each grid node and, thus, change of trades as well as power flows Source: Deliverable D2.1 “Report on uncertainty modeling”Analyzed
uncertainties
can
be used to anticipate
intraday
trades
Modeling uncertainties relevant for the operation of the European transmission grid 16 Brussels, 14/01/14POWER
PLANT OUTAGES
Modeling uncertainties relevant for the operation of the European transmission grid 17 Brussels, 14/01/14
Power
plant outages
Modelled
as Semi‐Markov‐Process
•
TTF:
time to fail
•
TTR:
time to repair
•
Av:
unit is available
•
Unav:
unit is unavailable
•
=1/MTTF
•
µ=1/MTTR
Modeling uncertainties relevant for the operation of the European transmission grid 18 Brussels, 14/01/14Probability
distribution of TTF and TTR
TTR
(initial state: unit is unavailable)
•
Weibull distribution
•
µ=scale
factor: MTTR
•
k=shape
factor: k>1 (bell‐shaped)
TTF
(initial state: unit is available)
•
Exponential
distribution (k=1)
•
µ=distribution
parameter: MTTF
Example: MTTR=70h, MTTF=1738.2h, Pav=0.9612, Punav=0.0387Modeling uncertainties relevant for the operation of the European transmission grid 19 Brussels, 14/01/14
COMBINATION
OF UNCERTAINTIES AND
PROVISION
OF OVERALL SYSTEM STATES
Modeling uncertainties relevant for the operation of the European transmission grid 20 Brussels, 14/01/14Deriving
forecast distributions for the system state/
Forecast
of Critical System States
Load
flow Calculations
Load
flow Calculations
Load
flow Calculations
Load
flow Calculations
Distributions
of load and RES infeed
Incorporation
of specifics, in particular related to
intraday
trading
Load
flow Calculations
Identification
of critical system states
P and Q (load) • Pump storages • International intraday trades • …Monte
‐Carlo‐Simulation
Distributions
of intraday trades
P and Q (load+injection) Source: Deliverable D2.1 “Report on uncertainty modelling”Modeling uncertainties relevant for the operation of the European transmission grid 21 Brussels, 14/01/14
Final
framework
Power
plant
DB
RES
point
forecast
Grid topology + aggregated load and infeedGrid
node
in
te
rf
ace
Prototype
DB on distribution parametersMonte
‐Carlo‐simulation of Uncertainty
Algorithms
of distribution
generation
In
‐ or output
Interfaces
Methods
Modeling uncertainties relevant for the operation of the European transmission grid 22 Brussels, 14/01/14Next
steps
• Finalizing solar power uncertainty for D and CZ
• Finalizing wind power uncertainty for D, PL, NL
and
AT
• Finalizing power plant outages for all participants
• Finalizing load uncertainty for all participants
• Make test interface for following tasks
• Aggregating all uncertainties
• Refinement
Modeling uncertainties relevant for the operation of the European transmission grid 23 Brussels, 14/01/14
Brussels, 14/01/14 Optimization algorithms for transmission system operation 1
Innovative Tools for the Future Coordinated Operation of the
Pan-European Electricity Transmission System
Optimization algorithms for transmission system operation
2nd iTesla/Umbrella Open Workshop, Brussels, 14-01-2014
Jonas Eickmann, Tobias van Leeuwen
Institute for Power Systems and Power Economics, RWTH Aachen University
Brussels, 14/01/14 Optimization algorithms for transmission system operation 2
Agenda
I.
Background and overview
II.
Challenges
III. Preliminary results
IV. Outlook
Brussels, 14/01/14 Optimization algorithms for transmission system operation 3
o
Growing complexity and importance of transmission system operation
Development of expert system to provide optimized guidance
Brussels, 14/01/14 Optimization algorithms for transmission system operation 4
Optimization for operational planning
Optimization algorithms
Network model including load/feed‐in Network related remedials Redispatch potential © SD 2013 © SD 2013 © SD 2013 Network use cases 0:30 0:30 2:302:30 4:304:30 6:306:30 8:308:30 10:3010:3012:3012:3014:3014:3016:3016:3018:3018:3020:3020:3022:3022:30 0:300:30 D D D+ 1 D+ 1 Contingency simulation Estimation of relevant contingencies Results Contingency listOutage A Branch i: , Node j: , Θ Outage B Branch k: , Outage …
Optimization of transmission system operation
Possible switching states Continuous optimization Topology optimization Network use cases 0:30 2:30 4:30 6:30 8:30 10:3012:3014:3016:3018:3020:3022:30 0:30 D D+ 1 Contingency simulation Estimation of relevant contingencies Results Contingency list
Outage A Branch i: , Node j: , Θ Outage B Branch k: , Outage …
Optimization of transmission system operation
Possible switching states Continuous optimization Topology optimization Remedial measure utilization Umbrella Optimization Tool
Secure network state
Uncertainty accounting in optimization Uncertainties
Brussels, 14/01/14 Optimization algorithms for transmission system operation 5
Agenda
I.
Background and overview
II.
Challenges
III. Preliminary results
IV. Outlook
V.
Conclusions
Brussels, 14/01/14 Optimization algorithms for transmission system operation 6
Challenges
System size
o
Large number of elements in European transmission grid
o
Cross border flows couple neighbouring transmission networks
(n-1)-criterion
o
Transmission grid operation needs to cope with contingencies
o
Optimization problem size grows linear with number of relevant outages
Discrete decisions
o
Several remedial actions require binary variables
Brussels, 14/01/14 Optimization algorithms for transmission system operation 7
Physical interpretation
o
Complete mathematical formulation of optimization problems in
transmission system operation computational barely feasible
Application of heuristic methods to reduce problem size and decouple
optimization sub problems
o
Optimization algorithms aim at identifying remedial measures for
congestion management
Minimizing deviation from initial operating point
o
Identification of relevant constraints
o
Neglecting dispensable contingencies
o
Predicting adjustments in the optimization procedure
o
Heuristic topology optimization
o
Searching topology modifications for specific congestions
o
Load flow approximation methods
Brussels, 14/01/14 Optimization algorithms for transmission system operation 8
Computational considerations
o
System size and performance
requirements are very
demanding from a
computational perspective
o
Scalability and maintainability
are key success factor
o
Available storage and
computational time limited
o
In depth analysis of the
optimization procedure shows
huge potential
Efficient data handling based on customized data structures and latest
programming techniques
Brussels, 14/01/14 Optimization algorithms for transmission system operation 9
Agenda
I.
Background and overview
II.
Challenges
III. Preliminary results
IV. Outlook
V.
Conclusions
Brussels, 14/01/14 Optimization algorithms for transmission system operation 10
Simulating remedial measures
Constraints
o
Currents
o
Voltages
in (n-1)-situations
Remedial measures
o
Topology switching
o
Transformers
oLongitudinal
oQuadrature
o
Redispatch
o
Shunt elements
o
HVDC lines
Network use cases 0:30 2:30 4:30 6:30 8:30 10:30 12:30 14:30 16:30 18:30 20:30 22:30 0:30 D D+ 1 Network use case Contingency simulation Estimation of relevant contingencies Results Contingency listOutage A Branch i: , Node j: , Θ Outage B Branch k: , Outage … Optimization of transmission system operation Possible switching states Continuous optimization Topology optimization
Brussels, 14/01/14 Optimization algorithms for transmission system operation 11
Result curative measures
0 20 40 60 80 100 Base Curative 10%Curative 20%Curative 30% Re d is p atc h co st s % Increase Curtailment
o
Simulation of 674 hours of the year 2010
o Generation estimated by market simulation o Synthetic network model based on public data o Assumption of 120% TATL on all lineso
Variation of curative (after outage) redispatch
o 0% (Base) to 30% of nominal powercuratively available
o
Comparison with real network operation
still pending
Brussels, 14/01/14 Optimization algorithms for transmission system operation 12 Congestions in base case Redispatch in base case Selected substations in base case Redispatch after TM 1, TM 2 Redispatch after TM 1 Selected substations after TM 1 165 % 100 % 104 % 105 % 126 % 104 % 101 % 98 % 107 % 107 % 126 % 107 % 99 % 103 % 104 % 107 % 98 % 105 % 104 % 98 % 108 % Before: 165 % After TM: 88 % Redispatch after TM 1, TM 2, TM 3 0 25 50 75 100 Zielfunktionswert Angepasste Leistung Redispatch Kosten Ausgangszustand TM 1 TM 1, TM 2 TM 1, TM 2, TM 3 %Result topology
Base case Objective function Redispatch powerRedispatch costs Curtailment Increase
Synthetic network model based on public data
Exemplary winter situation for year 2010
Load: 62.8 GW Wind infeed: 9.6 GW
Iterative estimation of three changes of
network topology (TM 1, TM 2, TM 3)
Base case does not represent todays
Brussels, 14/01/14 Optimization algorithms for transmission system operation 13
Real time optimization
Remedial
measures
Running
time
Enhanced
OPF:
Redispatch
Shunt
elements
HVDC
lines
10 sec
N
‐1 security OPF
3
min
Heuristic
topology
optimization
Extra
OPF for
each
candidate
line
Initial system stateEnhanced
OPF
OPF
Topology optimization Topology (fixed bus‐bars) Generation profile Constraints description Assigned values Optionally HVDC lines Shunt elements Transformers N‐1 security “Unprofitable” lines off Current injection methodology Brussels, 14/01/14 Optimization algorithms for transmission system operation 14Agenda
I.
Background and overview
II.
Challenges
III. Preliminary results
IV. Outlook
Brussels, 14/01/14 Optimization algorithms for transmission system operation 15
Uncertainty Accounting
o
Uncertainties can lead to critical system
states and higher risk of cascading events
due to insufficient network flexibility
Accounting uncertainties in operational planning
to minimize risk
o
Consideration of uncertainties beneficial for remedials with long
activation time, such as power plant start-ups
Concept:
o
Quantile-wise continuous optimization with penalties (probabilistic
criteria) separately for each branch to minimize risk
o
Finding standardized switching measures for uncertain use cases
o
Estimating the necessity for power plant start-ups
(N‐1) ‐ Expectation insecure system states Pr obabilit y Line Loading 85 90 95 100 % 110 Brussels, 14/01/14 Optimization algorithms for transmission system operation 16
Agenda
I.
Background and overview
II.
Challenges
III. Preliminary results
IV. Outlook
Brussels, 14/01/14 Optimization algorithms for transmission system operation 17
Conclusions
o
The developed algorithms promise to be capable of providing valuable
input to system operators by suggesting appropriate and secure
remedial measures
o
All required optimization steps can be carried out in day ahead time
horizon and even assist the operators in real-time
o
Further work will enable the consideration of uncertainties in the
operational planning processes
Brussels, 14/01/14 Optimization algorithms for transmission system operation 18
Thank
you very much for your attention!
Questions?
Comments?
www.e-umbrella.eu
This research work has been carried out within the scope of the project UMBRELLA, supported under the 7th Framework Programme of the European Union, grant agreement 282775.
4.4 Risk-based
Security
Assessment:
Brussels, 14/01/14 Risk‐based Security Assessment 1
Risk-based Security Assessment:
Incorporating Forecast Uncertainty and
Cascading Events
Brussels, 14-01-2014
Line Roald, Frauke Oldewurtel, Thilo Krause, Göran Andersson – ETH Zürich
Klaus Köck, Herwig Renner – TU Graz
Martijn de Jong, George Papaefthymiou, Domenico Lahaye – TU Delft
Brussels, 14/01/14 Risk‐based Security Assessment 2
Risk-based Security Assessment
I.
Objectives and Overview
II.
Risk-based Optimal Power Flow
III.
Risk-based Security Assessment
IV. Publications
Brussels, 14/01/14 Risk‐based Security Assessment 3
WP4: Objective
Goal: Maintaining power system security while
facilitating integration of renewable energy and
market operations!
Approach: Risk-based Security Assessment
o
Utilize information about
- forecast uncertainties
- outage probabilities
- availability of corrective measures
- cascading events
o
Develop
risk-based measures of power
system security for use in operational
planning and market design.
Severity
:
Expected
loss
Probability
Figure 1: Risk zones in operation based on different risk levels. [UCTE OH]
Risk =
Probability ∙ Severity
Brussels, 14/01/14 Risk‐based Security Assessment 4
WP4: Overview
Task
4.2: Evaluation of risk regarding
cascading
events
Task
4.3: Integration of state‐of‐the‐art
technological
means (e.g. FACTS)
Task
4.4: Evaluation of market designs
Task
4.1: Implementation of improved risk‐
based
methods, based on literature review
Comparison
with
ex
is
tin
g crit
eria
Risk
‐based security assessment
Brussels, 14/01/14 Risk‐based Security Assessment 5
Presentation Outline
I. Objectives and Overview
II.
Risk-based Optimal
Power Flow
III.
Risk-based Security
Assessment
IV. Publications
V. Key messages
contingency list
Risk-based
acceptable risk level Risk-based Optimal Power
Flow
Brussels, 14/01/14 Risk‐based Security Assessment 6
Risk-based Security Assessment
I.
Objectives and Overview
II.
Risk-based Optimal Power Flow
III.
Risk-based Security Assessment
IV. Publications
Brussels, 14/01/14 Risk‐based Security Assessment 7
II. Risk-based Optimal Power Flow (OPF)
Development and comparison of different OPF formulations:
1.
Probabilistic Security-Constrained OPF
2.
Risk-based, probabilistic SCOPF with remedial actions
3.
Risk-based SCOPF accounting for cascading risk
Brussels, 14/01/14 Risk‐based Security Assessment 8
II. Risk-based Optimal Power Flow (OPF)
Development and comparison of different OPF formulations:
1.
Probabilistic Security-Constrained OPF
Accounts for
normally distributed wind forecast uncertainty
2.
Risk-based, probabilistic SCOPF with remedial actions
Brussels, 14/01/14 Risk‐based Security Assessment 9
1. Probabilistic Security-Constrained OPF
o
Standard DC Optimal Power Flow formulation
o
Normal distributions of wind in-feed forecast errors
o
Deterministic constraint:
o
Probabilistic constraint:
ℙ
1
Brussels, 14/01/14 Risk‐based Security Assessment 10
1. Probabilistic Security-Constrained OPF
o
Standard DC Optimal Power Flow formulation
o
Normal distributions of wind in-feed forecast errors
o
Deterministic constraint:
o
Probabilistic constraint:
Φ
1
, 0 10 20 30 40 50 Line Number D e c re a s e [M W ] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38Lines
most influenced by wind in‐feed deviations have largest decrease!
Decrease
in line transfer capacity!
Brussels, 14/01/14 Risk‐based Security Assessment 11
1. Probabilistic Security-Constrained OPF
o
Influence of violation probability
ɛ
380 400 420 440 460 480 500 520 540 0 0.2 0.4 0.6 0.8 1 Line Flow [MW] Cu m u la ti v e P ro b a b ilit y
Exp. Value SCOPF Line Limit
CDF SCOPF
Brussels, 14/01/14 Risk‐based Security Assessment 12
1. Probabilistic Security-Constrained OPF
o
Influence of violation probability
ɛ
380 400 420 440 460 480 500 520 540 0 0.2 0.4 0.6 0.8 1 Line Flow [MW] Cu m u la ti v e P ro b a b ilit y
Exp. Value SCOPF Line Limit
CDF SCOPF
Brussels, 14/01/14 Risk‐based Security Assessment 13
1. Probabilistic Security-Constrained OPF
o
Influence of violation probability
ɛ
380 400 420 440 460 480 500 520 540 0 0.2 0.4 0.6 0.8 1 Line Flow [MW] Cu m u la ti v e P ro b a b ilit y
Exp. Value SCOPF Line Limit
CDF SCOPF
ɛ = 50% ɛ = 5%
Brussels, 14/01/14 Risk‐based Security Assessment 14
1. Probabilistic Security-Constrained OPF
o
Influence of violation probability
ɛ
Capacity decrease leads to the desired violation probability!
380 400 420 440 460 480 500 520 540 0 0.2 0.4 0.6 0.8 1 Line Flow [MW] Cu m u la ti v e P ro b a b ilit y
Exp. Value SCOPF Exp.Value pSCOPF Line Limit CDF pSCOPF CDF SCOPF ɛ = 50% ɛ = 5%
Brussels, 14/01/14 Risk‐based Security Assessment 15
1. Probabilistic Security-Constrained OPF
Effect of uncertainty on cost:
o
Cost of security
o
Introduction of additional
security constraints increases
cost
o
o
Cost of uncertainty
o
Tightening of line constraints
increases cost
o 0 20 40 60 80 100 120 Base Case Re la ti v e G e n e ra ti o n Co s t in % OPF pOPF SCOPF pSCOPF Brussels, 14/01/14 Risk‐based Security Assessment 161. Probabilistic Security-Constrained OPF
o
Extension to include state-of-the-art technological measures
o
Preliminary results:
o Preventive and corrective control of PSTs
Cost
decreases with
number
of PSTs
Corrective
control opportunities
influence
cost‐of‐security more
than
cost‐of‐uncertainty
Gener a tion Cos t [% of OPF] Gener a tion Cos t [% of OPF] Number of PSTs in the network OPF formulationBrussels, 14/01/14 Risk‐based Security Assessment 17
II. Risk-based Optimal Power Flow (OPF)
Development and comparison of different OPF formulations:
1.
Probabilistic Security-Constrained OPF
Accounts for
normally distributed wind forecast uncertainty
2.
Risk-based, probabilistic SCOPF with remedial actions
Accounts for
arbitrary wind forecast uncertainty
(sampling based)
Models risk based on
cost and availability of remedial actions
3.
Risk-based SCOPF accounting for cascading risk
Brussels, 14/01/14 Risk‐based Security Assessment 18
2. Risk-based, probabilistic SCOPF
accounting for remedial actions
Risk Modelling:
o
o
Piecewise linear severity function
o
Possibility to account for cost and availability
of remedial measures in the risk model
Risk-based Constraints:
o
Post-contingency line flow limit
depends on
outage probability
and
severity function
∙
Brussels, 14/01/14 Risk‐based Security Assessment 19
2. Risk-based, probabilistic SCOPF
accounting for remedial actions
o
Influence of violation level and risk limit:
Post-contingency overload
only in very few cases
Cost decreases when acceptable
violation level
ɛ or risk limit increase
Brussels, 14/01/14 Risk‐based Security Assessment 20
II. Risk-based Optimal Power Flow (OPF)
Development and comparison of different OPF formulations:
1.
Probabilistic Security-Constrained OPF
Accounts for
normally distributed wind forecast uncertainty
2.
Risk-based, probabilistic SCOPF with remedial actions