US 12,392,838 B2
Method and battery management system for monitoring a battery system by determining impedance
Michael Baumann, Munich (DE); Alexander Karger, Munich (DE); and Arpit Maheshwari, Munich (DE)
Assigned to TWAICE Technologies GmbH, Munich (DE)
Appl. No. 17/802,629
Filed by TWAICE Technologies GmbH, Munich (DE)
PCT Filed Mar. 1, 2021, PCT No. PCT/EP2021/054982
§ 371(c)(1), (2) Date Aug. 26, 2022,
PCT Pub. No. WO2021/170866, PCT Pub. Date Sep. 2, 2021.
Claims priority of application No. 10 2020 105 349.5 (DE), filed on Feb. 28, 2020.
Prior Publication US 2023/0109406 A1, Apr. 6, 2023
Int. Cl. G01R 31/389 (2019.01); B60L 58/16 (2019.01); G01R 31/367 (2019.01); G01R 31/3842 (2019.01); G01R 31/392 (2019.01); H01M 10/42 (2006.01); H01M 10/48 (2006.01)
CPC G01R 31/389 (2019.01) [B60L 58/16 (2019.02); G01R 31/367 (2019.01); G01R 31/3842 (2019.01); G01R 31/392 (2019.01); H01M 10/425 (2013.01); H01M 10/48 (2013.01); H01M 2010/4271 (2013.01); H01M 2010/4278 (2013.01); H01M 2220/20 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A method for determining one or more impedance parameters of a battery system, comprising:
providing a finite sequence of pairs of measured current and voltage values (Imeas,k; Umeas,k) that follow one another in time, the pairs of current and voltage values (Ik: Uk) indicating the current (IL) flowing through the battery system and the voltage (UL) present at the battery system at the corresponding point in time;
providing an electrical equivalent model of the battery system, wherein the electrical equivalent model has series-connected impedances (Z1, Z2, Z3, Z4);
providing initial impedance parameter values (Rohm,initial; Rct,initial; Reldiff,initial; Rsoldiff,initial) of the impedances of the equivalent electrical model;
adapting a first impedance parameter (Rsoldif) of an impedance (Z4) of the equivalent electrical model based on the difference between a first impedance parameter based on the initial impedance values (Rohm,0; Rct,0; Reldiff,0; Rsoldiff,0) and the first current value (I1) of the finite sequence of simulated voltage values (Usim,1) and the first measured voltage value (Umeas,1) of the finite sequence, whereby an optimized first impedance parameter value (Rsoldif,optimated) is obtained;
minimizing the deviation of a sequence of simulated voltage values (Usim,k) obtained on the basis of the equivalent electrical model and the first sequence of measured current values (Imeas,k) and the sequence of measured voltage values (Umeas,k) by adapting at least one further impedance parameter (Rohm; Rct; Reldiff) of the impedances (Z0, Z1, Z2, Z3, Z4) of the equivalent electrical model, whereby an optimized further impedance parameter value (Rohm,optimal; Rct,optimal; Reldiff,optimal) of the at least one further impedance parameter is obtained,
wherein the optimized first impedance parameter and the optimized further impedance parameters are used as initial impedance parameter values of a subsequent finite sequence, thereby improving subsequent determinations of impedance parameters.