Online Joint Estimation of SOC and SOP for High-rate Battery based on EKF

Abstract

Aiming at the problem of high precision and high safety estimation of state of power (SOP) of high-rate lithium-ion power battery in the application of special operation vehicle, this paper analyses the working characteristics of the high-rate lithium-ion power battery, and builds the second-order RC equivalent circuit model of the battery. The recursive least squares (RLS, Recursive Least Squares) algorithm is used to identify battery parameters online, and the SOC algorithm based on the extended Kalman filter and the SOP algorithm are used for joint estimation. This algorithm is used to solve the problem that the maximum allowable power of the actual battery caused by the degradation of battery life is difficult to calculate and even causes the problem of safe fire accidents. Combined with the correction algorithm in practical engineering, it ensures the efficiency and safety of the SOP estimation during the entire life cycle of the electric vehicle. This research has an important significant guiding in engineering practice.