Abstract:
A storage battery controller includes a charging/discharging rate setter which sets a rate at which the battery is charged/discharged to approximate the power system frequency to rated frequency; and a charge and discharge controller which controls charge and discharge of the battery, in which the gain adjuster: when the measured charge level is lower than a lower limit of a normal range and the obtained power system frequency is within a first non-sensitive zone ranging from a first frequency lower than the rated frequency to the rated frequency, decreases the charging rate to a predetermined percentage of the charging rate; and when the measured frequency is higher than an upper limit of the normal range and the obtained power system frequency is within a second non-sensitive zone ranging from a second frequency higher than the rated frequency to the rated frequency, adjusts the discharging rate to decrease the discharging rate.