Research on Evaluating the Health of Lithium-ion Battery Based on Double Kalman Filter Algorithm

Lithium-ion power battery has become one of the main power sources of new energy vehicles due to its high energy, low pollution and high safety. State of health (SOH) of power battery is the most important performance index of electric vehicle power battery system. However, the existing estimation of battery SOH mostly uses the off-line Kalman filter algorithm and it is unable to accurately describe the actual working condition. In this paper, the circuit model of lithium-ion battery is analyzed, the charge and discharge test system of lithium-ion battery is designed, and the online estimation method of double Kalman filter algorithm is designed to evaluate the battery health. Experimental results show that the design algorithm has higher accuracy and convergence.