Cell Balancing of Li-ion Battery Pack with Adaptive Generalised Extended State Observers for Electric Vehicle Applications

This article provides a diagnosing cell-to-cell variance with state-of-charge (SOC) estimate in series connected lithium-ion batteries. SOC estimation in voltage-based balancing increases the computational complexity of implementation. To avoid such problems, a simple current sensorless SOC estimation algorithm is proposed using a generalized extended state observer, which can realize the robustness of the system to disturbance. A constant current discharge/charging profile is applied to a series linked battery pack to check the parameters and establish the practicality of the proposed method. The experimental results show that the proposed controller have higher estimation accuracy and better SoC balancing mechanism.