Abstract: A technology for suppressing a performance degradation of a solar battery caused by PID is provided. A conversion device includes a DC/DC converter and a control part. A solar battery is connected to an input end of the DC/DC converter. When direct-current power generated by the solar battery is converted and output, the DC/DC converter makes a potential of a negative electrode of the solar battery to be higher than a potential in a negative electrode of the output when the power input from the solar battery exceeds a prescribed value. The control part changes a voltage of the power output from the solar battery to detect a peak value of the power, and stops the operation of the DC/DC converter when the peak value is smaller than the prescribed value.

Abstract: A technology for suppressing a performance degradation of a solar battery caused by PID is provided. A conversion device includes a DC/DC converter and a control part. A solar battery is connected to an input end of the DC/DC converter. When direct-current power generated by the solar battery is converted and output, the DC/DC converter makes a potential of a negative electrode of the solar battery to be higher than a potential in a negative electrode of the output when the power input from the solar battery exceeds a prescribed value. The control part changes a voltage of the power output from the solar battery to detect a peak value of the power, and stops the operation of the DC/DC converter when the peak value is smaller than the prescribed value.

Abstract: A power storage control device capable of charging a storage battery with a self-sustaining output of a PCS without the necessity of stopping a self-sustaining operation is provided. When a storage battery is charged with PCS's self-sustaining output, a control part generates a charging current command based on a standard charging current command, and controls the electric power conversion part according to the generated charging current command. The charging current command causes charging current command values in a predetermined range centered on “0” of the standard charging current command to approach “0”. The standard charging current command is time series data of the charging current command values designating a current extracted from the self-sustaining output of PCS, synchronized with PCS's self-sustaining output, and has an amplitude corresponding to a target value of electric power charged to the storage battery.

Abstract: As having a charge/discharge control function of storage batteries, when a plurality of power conditioners having a same basic switching period are installed together, hunting of charging/discharging power of the storage battery connected to each power conditioner is suppressed. Execution periods of control processes performed by control units 14 of a plurality of power conditioners 10 that have a function of controlling charging and discharging of storage batteries 25 are changed from basic switching periods so as to be different from each other.