A physics-based integer-linear battery modeling paradigm
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Authors
Scioletti, Michael S.
Goodman, Johanna K.
Kohl, Paul
Newman, Alexandra M.
Issue Date
2016
Type
journal-article
Language
Keywords
Optimization , Microgrid , Battery dispatch , Hybrid power , Rate-capacity , Steady-state
Alternative Title
Abstract
Optimal steady-state dispatch of a stand-alone hybrid power system determines a fuel-minimizing distribution strategy while meeting a forecasted demand over six months to a year. Corresponding optimization models that integrate hybrid technologies such as batteries, diesel generators, and photovoltaics with system interoperability requirements are often large, nonconvex, nonlinear, mixed-integer programming problems that are difficult to solve even using the most state-of-the-art algorithms. The rate-capacity effect of a battery causes capacity to vary nonlinearly with discharge current; omitting this effect simplifies the model, but leads to over-estimation of discharge capabilities. We present a physics-based set of integer-linear constraints to model batteries in a hybrid system for a steady-state dispatch optimization problem that minimizes fuel use. Starting with a nonlinear set of constraints, we empirically derive linearizations and then compare them to a commonly used set of constraints that assumes a constant voltage and neglects rate-capacity. Numerical results demonstrate that assuming a fixed voltage and capacity may lead to over-estimating discharge quantities by up to 16% compared to our overestimations of less than 1%.
Description
Citation
Scioletti et al., “A Physics-Based Integer-Linear Battery Modeling Paradigm.”
Publisher
Applied Energy
License
Journal
Volume
Issue
PubMed ID
ISSN
0306-2619