Abstract:

SOC is an important parameter of power batteries of electric vehicles. Its accurate estimation is vital to the correct implementation of the control strategy of the whole vehicle. It is strait to estimate SOC of the battery accurately using existing estimation methods. Aiming at the shortcomings in these methods, we proposed to establish an estimation model for battery SOC using principal component analysis (PCA) algorithm in this study. However, unable to extract non-linear factors in parameters, PCA algorithm would bring about an estimation error of battery SOC; thus, we proposed to establish an estimation model for battery SOC using kernel principal component analysis (KPCA) algorithm. The model was simulated and verified through experiments. After simulation, it shows that the improved model may adapt to a more complicated environment, meet the requirements of promptness and reliability, and has higher estimation accuracy with an average estimation error of 1.46%, which is better than that of Ah measurement method.