Frequency and Temporal Identification of a Li-ion Polymer Battery Model Using Fractional Impedance
Résumé
The modelling of high power Lithium batteries may work as a powerful tool in the sizing
of batteries pack in hybrid vehicles. Moreover, this tool can be used to evaluate
accurately the battery characteristics at each level of its lifetime. Until now, the model
structure differs according to its end-use due to simulation limitation. Indeed, impedance
measurements obtained by electrochemical impedance spectroscopy needs non-integer order
impedance in order to correctly model diffusive phenomenon. However, this impedance cannot
be simulated easily in software dedicated to hybrid vehicles and needs approximations.
Furthermore, impedance measurements are realised with low currents comparing to currents
that are forecast in normal uses of high power batteries and can induce errors if the
impedance is varying with the current. This paper deals with non linear dynamic models
that use band-limited frequency impedance with non-integer order. The parameters are
identified partly by impedance measurements for high frequencies and partly by
chronopotentiometry measurements for low frequencies. Validation tests are made with
staircase of high intensity and current profile simulated on a hybrid vehicle software.
The hypothesis of non-linearity is verified.
Domaines
Physique [physics]Origine | Publication financée par une institution |
---|