Learning Forum

[chinmaya.bhakta]

Hello,

I am trying to simulate a battery pack using MSMD or ECM model. I am using pulse discharge data (HPPC) to estimate the ECM parameters.

I did one pulse discharge test at 25 degree celsius ambient temperature with below stated procedure.

• Charge CC-CV (4.2V, C/20 cutoff)
• Rest : 30 min
• From 100% to 10% SOC:
• Relaxation  of 100 sec.
• Discharge pulse at 1C, (20 sec).
• Rest for 15 mins.
• Discharge at 1C to reduce 10% SOC
• Rest for 30 min.
• Repeat the discharge pulse.

I have attached the test data (voltage-time profiles obtained), for this data I am not able to achieve the curve fitting for all the SOC points.

For some SOC points curve fitting is done but for most of the SOC points curve fitting is getting failed.

Below I  have attached the voltage-time profiles obtained from the test.

Could someone please help me in knowing why curve fitting is failed ?

Is my test procedure correct ? If not could you please suggest the correct testing procedure

Your insights will be of great help for me

Regards

[Murari Iyengar]

Hi,

Are you using the correct format while loading the HPPC test data? Please refer 28.2. Using the MSMD-Based Battery Models (ansys.com) for the format.