Kabushiki Kaisha Toyota Jidoshokki

Hiroto Sato

Kenji Nishigaki

Toshio Otagiri

Ryusuke Hase

Junichi Hatano

Shinichi Aizawa

A power storage apparatus including a battery and a control circuit that controls the charging or discharging of the battery, wherein during a polarization elimination time period extending from the charging/discharging end time of the battery to a polarization-eliminated time at which polarization of the battery can be judged to have been eliminated, the control circuit obtains, as an amount of change, the difference between a voltage measured at a first time set according to the temperature of the battery and a voltage measured at a second time following the first time and set according to the temperature of the battery, and sums the product of the amount of change and an estimation coefficient and the voltage measured at the first or second time so as to estimate an open-circuit voltage of the battery to be provided after elimination of the polarization of the battery.

Power storage apparatus

Provided is a power storage apparatus including a battery and a control circuit that controls charging and discharging of the battery, wherein during a polarization elimination time period, the control circuit obtains, as an amount of change, a difference between a first voltage of the battery measured at a first time and a second voltage of the battery measured at a second time following the first time, multiplies the amount of change by an estimation coefficient that depends on the first voltage, the second voltage, a temperature of the battery, a temperature of a space around the battery, or a degree of deterioration of the battery, and sums the value obtained so as to estimate an open-circuit voltage to be provided after elimination of the polarization of the battery.

Power storage apparatus for estimating an open-circuit voltage

A battery state-of-charge estimation apparatus includes: a storage that stores a charge SOC-OCV curve, a discharge SOC-OCV curve, and internal-division-ratio information; and a state-of-charge estimation unit, wherein: when a capacity difference between a battery before and after charging when the battery is charged when an intersection point is on the discharge SOC-OCV curve or when a capacity difference between the battery before and after discharging when the battery is discharged when an intersection point is on the charge SOC-OCV curve is less than a threshold, the state-of-charge estimation unit references the internal-division-ratio information to determine an internal division ratio; and the state-of-charge estimation unit estimates the state of charge of the battery using the determined internal division ratio, the open-circuit voltage of the battery after elapse of a predetermined time period since the end of charging or discharging, the charge SOC-OCV curve, and the discharge SOC-OCV curve.

Growing community of inventors

Kariya, Japan

Hiroto Sato