The invention discloses a power
lithium battery SOC
estimation method based on the self-adaptive Kalman filtering method. The power
lithium battery SOC
estimation method comprises the following steps:at first, according to the dynamic characteristics of a
lithium ion battery, establishing a dual-polarization
equivalent circuit model of the battery; then, obtaining data through testing the performance of the
composite pulse power, identifying the characteristic parameter of the model, and adopting the
least squares fit to obtain a relation curve of the open-circuit
voltage and SOC; based on the relation curve of the open-circuit
voltage and SOC and the discrete equation of a DP model, establishing a state equation and an observation equation, and substituting the state equation and the observation equation into the EFK
algorithm to obtain a
system matrix; and finally, adopting the modified self-adaptive extended
Kalman filtering algorithm to estimate the battery SOC. With adoption of the power
lithium battery SOC
estimation method, the problems that the filtering results diffuse and the operation is not stable when the traditional self-adaptive Kalman filtering method or the EFK
algorithm is adopted for SOC estimation are effectively solved, and the speed that the SOC estimated value is convergent to the
truth value is increased.