| 摘要 |
PROBLEM TO BE SOLVED: To provide a device for estimating a parameter of an equivalent circuit model of a secondary battery that is designed to be able to precisely estimate the parameter of the equivalent circuit model while a vehicle is actually running.SOLUTION: An arithmetic unit 8 calculates the parameter of an RC series-parallel circuit in an equivalent circuit model after calculating Warburg impedance Zw. When calculating Warburg impedance Zw, the arithmetic unit 8 calculates the impedance Zw0 of a predetermined frequency f0, calculates the impedance Zw1 of frequencies f1 gradually low from the frequency f0, and, assuming that the impedance Zw1 of a first frequency f1 where the sum of a difference in the real part (Re(Zw1)-Re(Zw0)) and a difference in the imaginary part (Im(Zw1)-Im(Zw0)) of these is greater than or equal to a prescribed value Ze is a curved portion on a Nyquist diagram, calculates diffusion resistance Rand time constant τby using the impedance Zw1 of this frequency f1 (S11-S19). |
