SOC Estimation of Lithium-ion Battery Based on Ampere Hour Integral and Unscented Kalman Filter.

Based on Thevenin equivalent model, the second-order RC equivalent circuit model was established. The pulse discharge data of battery were obtained by the tests of hybrid pulse power characteristics, and the parameters of battery equivalent circuit were identified. In order to make up the iitiing errors of battery model parameter identification when the SOC of lithium-ion batteries was in the range of 90% to 100%, ampere hour integral and UKF were used comprehensively to estimate battery's SOC. Battery management system was designed by using HIL test platform and environmental simulation test platform. The results of SOC estimation of batteries under different operating conditions show that the estimation errors of SOC are from -1.5% to 1.0%. This method has relatively high accuracy and good effectiveness. [ABSTRACT FROM AUTHOR]