Parameter adaptive joint estimation of state of charge and available capacity based on multi-innovation-state estimator fusion

Accurate estimation of the state of charge (SOC) and available capacity is crucial for the rational use and safety protection of a battery. In this paper, an adaptive SOC estimation method based on a multi-innovation-state estimator is established. The SOC average error of this method is 0.0062 under different working conditions and temperatures. Furthermore, the expression of available capacity is obtained by transforming the SOC definition, and the estimation of the SOC and available capacity is realized by using the multi-innovation-state estimator. The multi-innovation-state estimator is suitable for the accurate estimation of available capacity under different aging conditions. The average error of the state of health (SOH) calculated using the estimated available capacity is <0.0081. Compared with the conventional SOH estimation method, the accuracy of the multi-innovation-state estimator is improved from 97.88 % to 99.63 %. The method proposed in this paper can lay a foundation for energy management and rational use of the battery.