| 摘要 |
PROBLEM TO BE SOLVED: To provide a battery state estimation apparatus that can calculate internal resistance of a secondary battery with high accuracy, and estimate a battery state of the secondary battery by reliably estimating battery capacity regardless of the reduced number of times of performing reset charge/discharge.SOLUTION: The battery state estimation apparatus comprises: a control section 6; and an internal resistance calculation section 9 connected with the control section 6 and for calculating internal resistance of a secondary battery. The internal resistance calculation section 9 executes wavelet transformation from respective values measured by a voltage measuring section 3 and a current measuring section 4, acquires wavelet coefficients of the current and the voltage for each frequency, and calculates internal resistance of the secondary battery from a ratio of the wavelet coefficients. When a relation between the wavelet coefficients of the current and the voltage is linearly approximated, the internal resistance calculation section 9 excludes the case in which correlation for the wavelet coefficients is lower than a predetermined reference, and calculates the internal resistance of the secondary battery. |
