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Non-linear charge-based battery storage optimization model with bi-variate cubic spline constraints

Non-linear charge-based battery storage optimization model with bi-variate cubic spline constraints

Category
Academic article
Abstract
Variable renewable generation demands increasing amount of flexible resources to balance the electric power system, and batteries stand out as a promising alternative. Battery models for optimization typically represent the battery with power and energy variables, while the voltage, current, charge variable space is used for simulation models. This paper proposes a non-linear battery storage optimization model in the voltage, current, charge variable space. The battery voltage is conceived as an empirical function of both state-of-charge and charge current and represented through bi-variate cubic splines. The voltage source converter losses are also approximated with a cubic spline function. Compared to energy-based storage models, the results show that this approach enables safe operation closer to the battery voltage and current limits. Furthermore, it prefers operating around high state-of-charge due to the higher efficiency in that region. © 2020 The Authors
Client
  • Research Council of Norway (RCN) / 257626
  • Research Council of Norway (RCN) / 272398
Language
English
Author(s)
Affiliation
  • Norwegian University of Science and Technology
  • SINTEF Energy Research / Energisystemer
  • CSIRO - Commonwealth Scientific and Industrial Research Organisation
Year
2020
Published in
Journal of Energy Storage
ISSN
2352-152X
Publisher
Elsevier
Volume
32