Improving Fast Charging Efficiency of Reconfigurable Battery Packs
Alexander Lamprecht1, Swaminathan Narayanaswamy2 and Sebastian Steinhorst2
1TUMCREATE, Singapore
alexander.lamprecht@tum-create.edu.sg
2Technical University of Munich, Germany
ABSTRACT
Recently, reconfigurable battery packs that can dynamically modify the electrical connection topology of their individual cells are gaining importance. While several circuit architectures and management algorithms are proposed in the literature, the electrical characteristics of the reconfiguration circuit architectures are not sufficiently studied so far. In this paper, we derive a detailed analytical model for a state-of-theart reconfiguration architecture capturing the losses introduced by the parasitic resistances of the circuit components. Based on this model we evaluate a novel fast charging strategy, which for the first time utilizes the reconfigurable battery pack architecture in order to reduce the losses during fast charging by switching between parallel and series connection of the cells. In order to do this, we consider the electrical characteristics of the reconfigurable circuit components. Since the component resistances are the main driver for the power losses during charging, we are able to give a realistic perspective on the overall pack performance and the efficiency increase due to the utilized fast charging strategy. Furthermore, using the analytical model, we highlight the challenges faced by existing reconfiguration architectures using state‐of‐the‐art components and we derive specifications for the switches for further improving the energy efficiency. Experimental results show that our strategy improves the charging efficiency by up to 10 %.
