Identification of lithium-ion-battery-cells based on physically interpretable models for battery state estimation during vehicle operation

• Applicants: Professor Dr.-Ing. Sören Hohmann; Professorin Dr.-Ing. Ellen Ivers-Tiffée
• Subject Area: Electrical Energy Systems, Power Management, Power Electronics, Electrical Machines and Drives
• Term: from 2015 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 270869123

A battery management system (BMS) is a key component of a modern electrified drive chain. In addition to safety functions an effective battery management system yields a perfect usage auf the battery itself and contributes significantly to a long lifetime of the vehicle’s battery and hence reduces the overall costs of an electric vehicle. For an effective BMS it is necessary that battery models base on (1) online available and (2) physically motivated parameters of the model. It is the aim of this project to couple parametric identification methods being online cable with non-parametric methods yielding a physical understanding. The online method identification to be developed bases on a fractional model of the battery, which allows a physical interpretation due to its specific structure, the parameters of which are identified by a new identification procedure. The procedure bases on the idea of “distribution of relaxation times” which has already been successfully applied to fuel cells. However it needs to be extended by a new method calculating the distribution of differential capacities. The competences of the IRS in the field of control engineering and the competences of the IWE in the field of impedance spectroscopy complement each other perfectly in this respect.

• DFG Programme: Research Grants