Control-Oriented Modeling of A Lithium-Ion Battery for Fast Charging ⋆

The fast charge battery control problem is characterized by the need to have a sufficiently detailed model that can capture both the charging process and the inevitable constraints that limit the rate of charging due to battery state of health requirements. Presently, it appears the minimal modeling requirements to address the charging problem in model based fashion are unknown. This work seeks to develop a modeling methodology covering a large range of applications through systematically simplifying the partial differential equations that describe battery dynamics. The effects of grid resolution and polynomial order on the complexity and accuracy of reduced order models have been investigated to provide insight into the minimum modeling requirements at different charge rates. The proposed models are intended for controller design and optimization applications including fast charge control.