Patent ID: 7847557

Claim:
A method of driving a battery management system that estimates an internal impedance of a battery including a plurality of cells, the method comprising: generating a battery equivalent model of the battery; receiving a terminal voltage signal and a charge and discharge current signal of the battery; generating a first discrete signal corresponding to the terminal voltage signal of the battery; generating a second discrete signal corresponding to the charge and discharge current signal of the battery; estimating the internal impedance of the battery by filtering the first discrete signal and the second discrete signal according to a frequency range corresponding to the battery equivalent model; generating a third discrete signal by filtering the first discrete signal according to the frequency range corresponding to the battery equivalent model; and generating a fourth discrete signal by filtering the second discrete signal according to the frequency range corresponding to the battery equivalent model, wherein the generating of the battery equivalent model comprises: calculating a first parameter, which represents a resistance overvoltage corresponding to the internal impedance of the battery; calculating a second parameter, which represents a charge transfer overvoltage; calculating a third parameter, which represents a diffusion overvoltage; and calculating a fourth parameter, which represents an open circuit voltage; dividing the first to fourth parameters according to a frequency domain; and the estimating of the internal impedance of the battery further comprises: filtering the first parameter by using a high-pass filter, filtering the second parameter by using a band-pass filter, and filtering the third and fourth parameters by using a low-pass filter.