Contributed Session Fri.2.MA 550

Friday, 13:15 - 14:45 h, Room: MA 550

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

Generation and expansion problems


Chair: Roman Cada



Friday, 13:15 - 13:40 h, Room: MA 550, Talk 1

Michael Lindahl
Discrete optimization support system for the collection grid in large offshore wind parks

Coauthor: Niels-Christian Fink Bagger


Offshore wind parks have in the recent years started to grow significantly in size making the task of deciding on how to build the cable collection grid a lot more complex. The goal is to connect all turbines down to a substation by using different types of cables. The objective is then to minimize the cost by minimizing the amount of cables, connections and loss of power. The project is made in collaboration with DONG Energy which is market leader in building offshore wind parks. A mathematical representation of the problem is given which is turned into a MIP model by linear approximations of the quadratic power losses. It is shown how the problem is simplified by removing uninteresting connections. In order to solve the problem within a reasonable time the local branching framework is used. The considered test case is the Anholt Project which is a large offshore wind park including 111 wind turbines and 1 substation. It is shown how this can be used, not only to reduce cost, but also to easily explore different scenarios and see how the solution is affected if different constraints are added or other properties are changed.



Friday, 13:45 - 14:10 h, Room: MA 550, Talk 2

Stefano Zigrino
A multistage stochastic model for the electric power generation capacity expansion problem of a price-taker power producer in a multi-year horizon

Coauthors: Marida Bertocchi, Laureano F. Escudero, Maria Teresa Vespucci


We consider the optimal electric power generation capacity expansion problem over a multi-year time horizon of a price-taker power producer, who has to choose among different production technologies, while taking into account regulatory constraints on CO2 emissions, incentives to generation from renewable energy sources and risk due to uncertainties of prices and of market share. A multi-stage stochastic MILP model is developed for determining the evolution of the generation system along the time horizon, with the aim of maximizing the expected total profit, subject to a set of constraints to be satisfied for each scenario. Additionally, the maximization of the expected profit is subject, alternatively, to first-order stochastic dominance constraints (sdc), for a set of profiles given by pairs of threshold profit values and probability of not reaching them, and to second-order sdc, whose set of profiles is given by pairs of threshold profit values and bounds on the expected shortfalls on reaching the thresholds. Provisional results are reported of a computational comparison between the following strategies: parameters’ expected value, risk neutral and first- and second-order sdc.



Friday, 14:15 - 14:40 h, Room: MA 550, Talk 3

Roman Cada
Optimizing nuclear fuel reload patterns


A nuclear reactor operates in cycles. At the end of every cycle a fraction of spent fuel assemblies is to be replaced by fresh ones. A new collection of fuel assemblies is to be distributed in the reactor core. It is necessary to meet all safety criteria and also minimize costs and maximize production of electrical energy.
We present several possible mathematical models which are suitable for attacking the problem. In general it is a multicriteria nonlinear combinatorial optimization problem.
We will also discuss a problem of multicycle optimization in which several consecutive fuel cyles are to be optimized.
Finally we present results obtained by the Athena code developed for VVER type reactors (but the use of it is not limited to them).


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