Parameters are not estimated for the SOC range 0- 60% while using parameter estimation application of MATLAB. How to resolve?

I am using parameter estimation application of MATLAB to estimate 2 RC equivalent circuit parameters for the battery Panasonic 18650 battery HPPC data set available in Mandeley open source. Initially Panasonic 18650 table based battery model is developed in simulink. and current pulses are fed from HPPC data set for perticular temperature. Ouput voltage of te model is compared with experimatal terminal voltage data available from Mandeley open source. Circuit parameters are estimated based on the error in trminal voltage using parameter estimation application of MATLAB. It works and after defined no of iteration say 10, estimation will stop. But when we observe estimated parameters R0, R1, C1, R2, C2, it was found that parameters are at initial values only for SOC less than 63%. Kindly help me in resolving this.

Thank You,

Girisha Joshi

Answer 1

[Javier Gazzarri]

Hello Girisha

Please check the cell capacity that you defined. The tool uses coulomb counting based on the total capacity to determine the SOC breakpoint it is at, so if the capacity is not correct, the optimizer will be acting on the wrong SOC breakpoint.

Hope this helps. Best regards,

Javier