Estimation of internal states of 18650 lithium-ion batteries by Sigma-Point Kalman Filter

In this paper, Sigma-Point Kalman Filter(SPKF) has been adopted to estimate the internal states of 18650 lithium-ion battery. An equivalent circuit model of lithium-ion battery has been build. The initial parameters of the model can be calculated through the experimental data of the Hybrid Pulse Power Characterization (HPPC). In addition, the state space equation and output equation based on the circuit model have been defined. Then the algorithm of SPKF is been simulated by MATLAB software. The result proves that the computational internal states of battery is effective and estimation accuracy is relatively high.