Management device and power storage system
In management device ( 10 ) for managing power storage device ( 20 ) in which a plurality of power storage blocks (B 1 to B 3 ) in which a plurality of series circuits of fuses and power storage cells is connected in parallel is connected in series, equalization controller 15 performs, when a voltage difference among the power storage blocks exceeds a set voltage difference, a control for equalizing power storage blocks (B 1 to B 3 ). Fuse blowout determination unit 18 determines, based on a frequency of equalization performed by equalization controller 15 , whether one of the fuses is blown.
1. A management device for managing a power storage device, in which a plurality of power storage blocks, where a plurality of series circuits each configured of a fuse and a power storage cell are connected in parallel, are connected in series, the management device comprising:
an equalization controller for performing, when at least one voltage difference among the power storage blocks exceeds a set voltage difference, a control for equalizing the power storage blocks; and
a blowout determination unit for determining, based on a frequency of equalization performed by the equalization controller, whether at least one of the fuses is blown.
2. The management device according to claim 1 , further comprising voltage detectors for detecting voltages of the power storage blocks,
wherein the blowout determination unit determines that, when the frequency of equalization is higher than a set frequency, at least one of the fuses is blown.
3. The management device according to claim 2 , wherein, for the set frequency, a different value in accordance with a State Of Health (SOH) is used.
4. The management device according to claim 1 , wherein
the equalization controller performs, in a period during which the power storage device is neither charged nor discharged, a control for equalizing the power storage blocks,
the management device further includes an equalization implementation information acquisition unit for acquiring information on implementation of a control for equalizing the power storage blocks, and information indicating that a state before the control for equalization is performed is either of a charging state and a discharging state, and
the blowout determination unit determines, based on a frequency of equalization of the power storage blocks performed after charging and a frequency of equalization of the power storage blocks performed after discharging, whether at least one of the fuses included in the power storage blocks is blown.
5. The management device according to claim 4 , wherein
the equalization controller causes, when, among the plurality of power storage blocks included in the power storage device, one of the power storage blocks has a least voltage, at least another one of the power storage blocks to discharge electricity so that a voltage of the at least another one of the power storage blocks lowers closer to the least voltage, and
the blowout determination unit determines that,
when an integral time of equalization performed, for a certain period, after one of the power storage blocks is charged is greater by a first set value or more than an average integral time of equalization performed, for the certain period, after another one of the power storage blocks is charged,
and when an integral time of equalization performed, for the certain period, after the one of the power storage blocks is discharged is smaller by a second set value or more than an average integral time of equalization performed, for the certain period, after the another one of the power storage blocks is discharged,
at least one of the fuses included in the one of the power storage blocks is blown.
6. A power storage system comprising:
a power storage device; and
the management device for managing the power storage device, according claim 1 .