Universidad Pontificia Comillas
  Instituto de Investigación Tecnológica
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[Principal] [Résumé/CV] [Material docente] [Operations Management] [Mathematical Methods] [Operations Research] [Técnicas de Optimización de Sistemas] [Modelado y Simulación de Sistemas] [Applied Optimization] [Statistics II] [Quantitative Decision Methods] [Optimization Techniques] [Deterministic Optimization] [Stochastic Optimization] [Investigación] [Open Models] [openSDUC] [openTEPES] [TEPES] [ROM] [StarNet] [FLOP] [iMetro]

TEPES Model (Long-Term Transmission Expansion Planning Model for an Electric System)
 
 


Desertec2050

Nigeria

Beyond2020

Desertec2030

 

The intermittent nature of the output of most renewable energy resources (RES), its non homogeneous distribution and the deployment of a large share of this generation is expected to result in a significant increase in the power flows among areas in large-scale systems. As a result of this, the development of the network of the system should be planned in an integrated way and the number of operation snapshots to consider in the planning process should probably be high. Identifying main optimal transmission network corridors to reinforce and the extent of reinforcements needed in them, and other operation variables affected by the existence of the grid, like investment cost of grid additions, network losses incurred, CO2 emissions produced, overall production by technology and fuel production costs is a major challenge for large-scale systems. Different future RES generation strategies associated with different RES targets may also strongly influence this network development.

Transmission expansion planning (TEP) determines the investment plans of new facilities (lines and other network equipment) for supplying the forecasted demand at minimum cost. Tactical planning is concerned with time horizons of 10-20 years. Its objective is to evaluate the future network needs. The main results are the guidelines for future structure of the transmission network.
TEPES model presents a decision support system for defining the transmission expansion plan of a large-scale electric system at a tactical level. A transmission expansion plan is defined as a set of network investment decisions for future years. The candidate lines are pre-defined by the user so the model determines the optimal decisions among those specified by the user, or identified automatically by the model. Candidate lines can be HVDC or HVAC circuits.
The model determines automatically optimal expansion plans that satisfy simultaneously several attributes. Their main characteristics are:

  • Dynamic: the scope of the model corresponds to several years at a long-term horizon, 2020 or 2030 for example.

    The model represents hierarchically the different time scopes to take decisions in an electric system: Year, Period, Sub-period and Load level.
    This time division allows a flexible representation of the intervals where to evaluate the system operation. For example, by a set of non chronological isolated snapshots or by a set of representative days for different seasons of the year or by a stepwise load-duration curve covering the duration of a year. Currently, hourly representation of the operation of the electric power system of a year is usually done.

  • Stochastic: several stochastic parameters that can influence the optimal transmission expansion decisions are considered. The model considers stochastic scenarios related to operation and to reliability. The operation scenarios are associated to: renewable energy sources, electricity demand, hydro inflows, and fuel costs. The reliability scenarios evaluate N-1 generation and N-1 transmission contingencies.
  • Multicriteria: the objective function incorporates some of the main quantifiable objectives: transmission investment and variable operation costs (including generation emission cost), reliability cost associated to N-1 generation and transmission contingencies.

The optimization method used is based on a functional decomposition between an automatic transmission plan generator (based on optimization) and an evaluator of these plans from different points of view (operation costs for several operating conditions, or reliability assessment for N-1 generation and transmission contingencies). The model is based on Benders decomposition where the master problem proposes network investment decisions and the operation subproblem determines the operation cost for this investment decisions and the reliability subproblems determine the not served power for the generation and transmission contingencies given that investment decisions.
The operation model (evaluator) is based on a DC load flow although a simpler transportation representation is allowed for some or all the lines. Network losses can also be considered. By nature, the transmission investment decisions are binary although can also be treated as continuous ones. The current network topology is considered as the starting point for the network expansion problem.

The main results of the model can be structured in these topics:

  • Investment: investment decisions and cost
  • Operation: output of different units and technologies (thermal, storage hydro, pumped storage hydro, RES), fuel consumption, RES curtailment, hydro spillage, hydro reservoir scheduling, line flows, line ohmic losses, node voltage angles
  • Emissions: CO2
  • Marginal: Short-run Marginal Costs, Transmission Load Factors (TLF)
  • Reliability: ENS (Energy Not Served)
  • Cost to go function or future cost function

The results are grouped by node, zone, area and region.

TEPES is written in GAMS taking advantage of grid computing and sensitivity analysis with a Microsoft Excel input/output interface and requires a licence for one of the optimization solvers linked with GAMS. Some of the optimization solvers are free for academics, but must be registered with a degree-issuing academic institution. TEPES can be installed under Microsoft Windows 10 64 bits or under Linux or MacOS.

A new open and simplified version of the model written in Python/Pyomo can be found in:

Open Generation and Transmission Operation and Expansion Planning Model with RES and ESS (openTEPES)

This model is currently being used and improved in some European research projects:

The model is also aimed at computing the benefits of transmission expansion projects by a methodology developed at IIT and also by the two possible approaches proposed by ENTSO-E: the Take Out One at a Time (TOOT) and the Put In one at a Time (PINT).

Some TEP related publications:

F. Holz, T. Scherwath, P. Crespo del Granado, Ch. Skar, L. Olmos, Q. Ploussard, A. Ramos, A. Herbst A 2050 perspective on the role for Carbon Capture and Storage in the European power system and industry sector. Energy Economics, October 2021 10.1016/j.eneco.2021.105631

S. Lumbreras, H. Abdi, A. Ramos, and M. Moradi Introduction: The Key Role of the Transmission Network in the book S. Lumbreras, H. Abdi, A. Ramos (eds.) Transmission Expansion Planning: The Network Challenges of the Energy Transition Springer, 2020 ISBN 9783030494278 10.1007/978-3-030-49428-5

R. Espejo, G. Mestre, F. Postigo, S. Lumbreras, A. Ramos, T. Huang andE. Bompard Exploiting graphlet decomposition to explain the structure of complex networks: the GHuST framework Scientific Reports 10, Jul 2020 10.1038/s41598-020-69795-1

Rafael Espejo A Complex-Network Approach to Support Transmission Expansion Planning. PhD Thesis. Universidad Pontificia Comillas. October 2019. (Summary). Directors: Andrés Ramos, Sara Lumbreras.

Q. Ploussard, L. Olmos and A. Ramos A search space reduction method for transmission expansion planning using an iterative refinement of the DC Load Flow model IEEE Transactions on Power Systems 35 (1): 152-162, Jan 2020 10.1109/TPWRS.2019.2930719

Th. Marge, S. Lumbreras, A. Ramos, and B.F. Hobbs Integrated offshore wind farm design: Optimizing micro-siting and cable layout simultaneously Wind Energy 10.1002/we.2396

Quentin Ploussard Efficient reduction techniques for a large-scale Transmission Expansion Planning problem. PhD Thesis. Universidad Pontificia Comillas. May 2019. (Summary). Directors: Luis Olmos, Andrés Ramos.

R. Espejo, S. Lumbreras, A. Ramos, T. Huang, and E. Bompard An Extended Metric for the Analysis of Power-Network Vulnerability: The Line Electrical Centrality IEEE PowerTech. Milano, Italy. June 2019

S. Lumbreras, A. Ramos Better Transmission Networks for a Smarter Global System in the book A. Tascikaraoglu and O. Erdinc (eds.) Pathways to a Smarter Power System. Academic Press 2019 ISBN 9780081025925

R. Espejo, S. Lumbreras, A. Ramos A Complex-Network Approach to the Generation of Synthetic Power Transmission Networks IEEE Systems Journal 13(3), 3050-3058, Sep 2019 10.1109/JSYST.2018.2865104

R. Espejo, S. Lumbreras, A. Ramos Analysis of transmission-power-grid topology and scalability, the European case study Physica A: Statistical Mechanics and its Applications 509, 383-395, Nov 2018 10.1016/j.physa.2018.06.019

Q. Ploussard, L. Olmos and A. Ramos An efficient network reduction method for transmission expansion planning using multicut problem and Kron reduction IEEE Transactions on Power Systems 33 (6): 6120-6130, Nov 2018 10.1109/TPWRS.2018.2842301

J.G. Dedecca, S. Lumbreras, A. Ramos, R.A. Hakvoort, P.M. Herder Expansion Planning of the North Sea Offshore Grid: Simulation of Integrated Governance Constraints Energy Economics 72, 376-392, May 2018 10.1016/j.eneco.2018.04.037

A. Held, M. Ragwitz, F. Sensfuß, G. Resch, L. Olmos, A. Ramos, M. Rivier How can the renewables targets be reached cost effectively? Policy options for the development of renewables and electricity networks Energy Policy 116, 112-126, May 2018 10.1016/j.enpol.2018.01.025

S. Lumbreras, A. Ramos, F. Banez-Chicharro, L. Olmos, P. Panciatici, C. Pache, J. Maeght Large-scale Transmission Expansion Planning: from zonal results to a nodal expansion plan IET Generation, Transmission & Distribution 11 (11), 2778-2786, Aug 2017 10.1049/iet-gtd.2016.1441

S. Lumbreras, F. Banez-Chicharro, A. Ramos Optimal Transmission Expansion Planning in Real-Sized Power Systems with High Renewable Penetration Electric Power Systems Research 49, 76-88, Aug 2017 10.1016/j.epsr.2017.04.020

F. Banez-Chicharro Methodology for Benefit Analysis of Transmission Expansion Projects PhD Thesis. Universidad Pontificia Comillas. June 2017 (Summary).

F. Banez-Chicharro, L. Olmos, A. Ramos and J.M. Latorre Beneficiaries of Transmission Expansion Projects of an Expansion Plan: An Aumann-Shapley Approach Applied Energy 195, 382-401, June 2017 10.1016/j.apenergy.2017.03.061

F. Banez-Chicharro, L. Olmos, A. Ramos and J.M. Latorre Estimating the benefits of transmission expansion projects: an Aumann-Shapley approach Energy 118 (1): 1044-1054, Jan 2017 10.1016/j.energy.2016.10.135

Q. Ploussard, L. Olmos and A. Ramos An operational state aggregation technique for transmission expansion planning based on line benefits IEEE Transactions on Power Systems 32 (4): 2744-2755 Oct 2017 10.1109/TPWRS.2016.2614368

S. Lumbreras, A. Ramos How to Solve the Transmission Expansion Planning (TEP) Problem Faster: Acceleration Techniques Applied to Benders Decomposition IET Generation, Transmission & Distribution 10: 2351-2359, Jul 2016 10.1049/iet-gtd.2015.1075

S. Lumbreras, A. Ramos The new challenges to transmission expansion planning. Survey of recent Lab and literature review Electric Power Systems Research 134: 19-29, May 2016 10.1016/j.epsr.2015.10.013

S. Lumbreras, D.W. Bunn, A. Ramos, M. Chronopoulos Real Options Valuation Applied to Transmission Expansion Planning Quantitative Finance 16(2): 231-246 February 2016 10.1080/14697688.2015.1114362

S. Lumbreras, A. Ramos, L. Olmos, F. Echavarren, F. Banez-Chicharro, M. Rivier, P. Panciatici, J. Maeght, C. Pache Network Partition Based on Critical Branches for Large-Scale Transmission Expansion Planning IEEE PowerTech. Eindhoven, The Netherlands. June 2015 10.1109/PTC.2015.7232344

F. Bañez, L. Olmos, A. Ramos, J.M. Latorre Benefit allocation of transmission expansion plans based on Aumann-Shapley IIT-14-050A, October 2014

S. Lumbreras, A. Ramos, P. Sánchez Offshore Wind Farm Electrical Design using a Hybrid of Ordinal Optimization and Mixed Integer Programming Wind Energy 18(12): 2241-2258 Dec 2015 10.1002/we.1807

S. Lumbreras Decision Support Methods for Large-Scale Flexible Transmission Expansion Planning PhD Thesis. Universidad Pontificia Comillas. June 2014 (Summary).

C. Duro Transmission Expansion Planning using a Genetic Algorithm. Final project of Engineering Degree. Universidad Pontificia Comillas. June 2014 (Resumen)

S. Lumbreras, A. Ramos, P. Sánchez Automatic Selection of Candidate Investments for Transmission Expansion Planning International Journal of Electrical Power and Energy Systems 59: 130-140, July 2014 10.1016/j.ijepes.2014.02.016

S. Lumbreras, A. Ramos Transmission Expansion Planning using an Efficient Version of Benders’ Decomposition. A Case Study IEEE PowerTech. Grenoble, France. June 2013 10.1109/PTC.2013.6652091

M. Banzo and A. Ramos Optimization of AC Electric Power Systems of Offshore Wind Farms in the book P. Pardalos, S. Rebennack, M.V.F.Pereira, N.A. Iliadis, and V. Pappu (eds.) Handbook of Wind Power Systems. Springer 2014 ISBN 9783642410796

S. Lumbreras, A. Ramos and S. Cerisola A Progressive Contingency Incorporation Approach for Stochastic Optimization Problems IEEE Transactions on Power Systems 28 (2): 1452-1460, May 2013 10.1109/TPWRS.2012.2225077

S. Lumbreras and A. Ramos Optimal Design of the Electrical Layout of an Offshore Wind Farm: a Comprehensive and Efficient Approach Applying Decomposition Strategies IEEE Transactions on Power Systems 28 (2): 1434-1441, May 2013 10.1109/TPWRS.2012.2204906

S. Lumbreras and A. Ramos Offshore Wind Farm Electrical Design: A Review Wind Energy 16 (3): 459-473 April 2013 10.1002/we.1498

Ch. Egeruoh Long-Term Transmission Expansion Planning for Nigerian Deregulated Power System. A systems approach Master Thesis. Universidad Pontificia Comillas. July 2012

A. Ramos, S. Lumbreras A Dynamic Stochastic Transmission Planning Model Solved by Efficient Benders’ Decomposition 9th International Conference on Computational Management Science (CMS2012) London, UK April 2012

S. Lumbreras, A. Ramos A Benders' Decomposition Approach for Optimizing the Electric System of Offshore Wind Farms IEEE PowerTech. Trondheim, Norway June 2011 (Presentation) 10.1109/PTC.2011.6019371

M. Banzo and A. Ramos Stochastic Optimization Model for Electric Power System Planning of Offshore Wind Farms IEEE Transactions on Power Systems 26 (3): 1338-1348 Aug 2011 10.1109/TPWRS.2010.2075944

P. Sánchez-Martín, A. Ramos, J.F. Alonso Probabilistic mid-term transmission planning in a liberalized market IEEE Transactions on Power Systems 20 (4): 2135-2142 Nov 2005 10.1109/TPWRS.2005.856984

P. Sánchez-Martín, A. Ramos Modeling Transmission Ohmic Losses in a Stochastic Bulk Production Cost Model October 1997

J.I. Pérez Arriaga, A. Ramos, G. Latorre Volumen 1: Guía de usuario del programa de planificación estática de la red de transporte a largo plazo PERLA. Volumen 2: Casos ejemplo. IIT-93-053 Julio 1991 Preparado para Red Eléctrica de España, S.A.

G. Latorre, A. Ramos, J.I. Pérez Arriaga, J.F. Alonso, A. Sáiz PERLA: Un modelo de planificación estática a largo plazo de la red de transporte. Opciones de modelado y análisis de idoneidad II Jornadas Hispano Lusas de Ingeniería Eléctrica 1: 3.46-3.54 Coimbra, Portugal Julio 1991

J.F. Alonso, A. Sáiz, L. Martín G. Latorre, A. Ramos, I.J. Pérez-Arriaga PERLA: An Optimization Model for Long-Term Expansion Planning of Electric Power Transmission Networks IIT-91-009 January 1991

G. Latorre, J.I. Pérez Arriaga, A. Ramos, J. Román, J.F. Alonso, A. Sáiz Un modelo de planificación estático de la red de transporte a largo plazo I Jornadas Hispano Lusas de Ingeniería Eléctrica 2: 521-533 Vigo, España Julio 1990