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

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

Category

Academic article

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

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