A Comparative Study of Open-Circuit-Voltage Estimation Algorithms for Lithium-Ion Batteries in Battery Management Systems

The studies dedicated to the battery open-circuit-voltage (OCV) online estimation are not as much as the research efforts on the state-of-charge (SOC) determination and the parameter identification such as capacity and resistance. However, as an important term that represents the distinct characteristic of different Lithium-Ion batteries, OCV should also be estimated. Four estimation algorithms, namely, Luenberger observer, Kalman filter, Recursive least-square with forgetting factor and Recursive least-square with variable forgetting factor are selected and compared in terms of estimation accuracy, computational cost, parameter tuning and robustness to model parameters variations. Simulation results have shown that observer-based methods exhibit better estimation performances than regression-based ones.