Invited Session Tue.3.MA 550

Tuesday, 15:15 - 16:45 h, Room: MA 550

Cluster 18: Optimization in energy systems [...]

Mathematical optimization for mid-term operation planning in gas networks

 

Chair: Marc C. Steinbach

 

 

Tuesday, 15:15 - 15:40 h, Room: MA 550, Talk 1

Björn Geißler
A new approach for solving MINLPs applied to gas network optimization

Coauthors: Alexander Martin, Antonio Morsi, Lars Schewe

 

Abstract:
We present a new approach to solve MINLPs which is based on the
construction of MIP-relaxations of arbitrary tightness. To construct these relaxations we extend some well-known MIP-techniques for piecewise linear approximations with the aid of convex underestimators and concave overestimators such that the resulting MIP-model is a proper relaxation of the underlying MINLP. After solving these relaxations, we fix the values of the integer variables and solve the remaining NLP. We apply our algorithm to the gas network nomination validation problem and provide numerical evidence for its suitability on small as well as on large-scale real-life instances.

 

 

Tuesday, 15:45 - 16:10 h, Room: MA 550, Talk 2

Bernhard Willert
A high accuracy optimization model for gas networks

Coauthors: Martin Schmidt, Marc C. Steinbach

 

Abstract:
Despite new regulations in the gas market and increasingly challenging transport situations, often gas transport networks are still balanced manually by using simulation software. The application of a high accuracy optimization model would increase the network efficiency and decrease the operational costs. We will present a suitable optimization model supporting different levels of detail for gas physics and technical network elements. Numerical results will underline its accuracy compared to a commercial simulation software and its practicability will be shown.

 

 

Tuesday, 16:15 - 16:40 h, Room: MA 550, Talk 3

Jesco Humpola
Topology optimization for nonlinear network flows

Coauthors: Benjamin Hiller, Thomas Lehmann, Robert Schwarz, Jonas Schweiger

 

Abstract:
A gas network consists of active elements such as valves and compressors, and passive elements like pipelines between sources and sinks. Most of the elements are pipelines where the flow is induced by a non-linear and non-convex relationship of the pressure differences at their end nodes. The topology optimization problem is to determine a cost-optimal physical state of each active element in order to transport a specified flow through the network without violating physical or operational constraints. This is modeled as a mixed integer non-linear program. Discrete decisions correspond to active network elements, and the non-linearity origins from described gas flow properties.
A sub-problem of this model has several convex relaxations. We present a framework which yields a global optimal solution for this large-scale topology optimization problem. This is implemented as a special tailored combination of the solvers SCIP and IPOPT. Preliminary computational results based on real-world instances with several hundred nodes and about 3000 arcs are presented. The data for this study is provided by Open Grid Europe GmbH (OGE), the leading German gas transportation company.

 

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