No abstract

Battery Management Systems (BMSs) require control-oriented models. Physics-based electrochemical models describe detailed battery phenomena, but are too computationally intensive for use in BMSs. Single Particle Models (SPMs) are often used for control-oriented battery modeling since they are physics-based and computationally efficient; however, they are only valid over very low frequency ranges and C-rates. Empirical Equivalent Circuit Models (ECMs) are also used in BMSs since they are computationally efficient and describe battery behavior over wide frequency ranges; however, they provide no physical understanding of the battery and often employ fractional order terms. This work provides a control-oriented battery model that combines the benefits of SPM and ECM models, while overcoming their limitations. The proposed model incorporates some of the battery physics found in electrochemical models, can easily be used in both the time and frequency domains, and describes battery behavior over its entire frequency range. A linearized SPM models battery physics at very low frequencies. For low frequencies, integer-order linear systems are used to approximate diffusion physics, and high frequency behavior is modeled by the double layer capacitance effect. The model is validated in the time and frequency domains via a comparison to Pseudo 2-Dimensional (P2D) model simulations and experimental data.