| 主权项 |
1. A charge state estimation device of a secondary battery for estimating a charge state value SOC of the secondary battery repeatedly charged and discharged in a short time, the charge state estimation device comprising:
a current/voltage acquiring unit for acquiring a charge or discharge current value and an inter-terminal voltage value of the secondary battery at a predetermined sampling time interval; a combined current calculating unit for calculating, by a predetermined current combining method, a combined current value Iw(t) from the charge or discharge current value I(t) acquired at a time t in consideration of a charge or discharge state before the time t; an estimation time setting unit for setting, as an estimation time for charge state estimation, a time t=T at which the combined current value Iw(t) exists within a predetermined threshold range; an internal resistance estimating unit for estimating an internal resistance value R of the secondary battery based on the inter-terminal voltage value V(T) and the charge or discharge current value I(T) of the secondary battery at the estimation time T and the inter-terminal voltage value V(T−n) and the charge or discharge current value I(T−n) of the secondary battery at a sampling time (T−n) before the estimation time T, the n being a natural number of 1 or more; and a charge state estimating unit for estimating an open circuit voltage value Voc of the secondary battery based on the inter-terminal voltage value V(T) of the secondary battery at the estimation time T and the internal resistance value R, and estimating the charge state value SOC of the secondary battery based on a Voc-SOC relation showing a relationship between the previously determined open circuit voltage value Voc and the charge state value SOC. |
