Jitter solution in parameter identification based on cross-time scale fusion algorithm of lithium-ion batteries

Area of Science:

• Electrical Engineering
• Materials Science
• Computational Science

Background:

• Accurate state-of-charge (SOC) estimation is critical for battery management systems (BMS).
• Equivalent Circuit Model (ECM) parameter identification can suffer from jitter and divergence under complex operating conditions, impacting SOC estimation accuracy.
• Existing methods struggle with parameter stability in dynamic battery usage scenarios.

Purpose of the Study:

• To develop a novel algorithm for robust ECM parameter identification and accurate SOC estimation.
• To address the jitter and divergence issues in ECM parameter identification under complex conditions.
• To enhance the overall performance and reliability of battery management systems.

Main Methods:

• The proposed Cross Time Scale Fusion (CTSF) algorithm utilizes two distinct time scales for parameter identification and SOC estimation.
• Forgetting Factor Recursive Least Square (FFRLS) is employed for ECM parameter identification within a specific time scale.
• SOC estimation is performed based on the identified parameters, with iterative cycling across the cross-time scales.

Main Results:

• The CTSF algorithm effectively mitigates jitter in ECM parameter identification across various operating conditions and temperatures.
• Significant improvements in SOC estimation accuracy were observed, with a minimum Mean Absolute Error (MAE) of 1.42% under varying conditions at constant temperature.
• A minimum MAE of 0.25% was achieved for varying temperatures under constant operating conditions, demonstrating enhanced accuracy.

Conclusions:

• The CTSF algorithm provides a robust solution for stable ECM parameter identification.
• The proposed method substantially improves the accuracy of battery SOC estimation, particularly under complex and dynamic conditions.
• This advancement contributes to more reliable and efficient battery management systems.