Abstract: A power management device includes: a first determination unit that determines whether or not an execution condition for executing cell balancing for equalizing states of charge of a plurality of battery cells included in a storage battery connected to a direct current (DC) bus via a converter is satisfied; and a control unit that performs cell balancing execution control for causing a battery management device managing the storage battery to execute the cell balancing when the execution condition is satisfied. The control unit changes a target voltage of the converter so that a state of charge of the storage battery becomes a state in which the battery management device starts the cell balancing in the cell balancing execution control.

Abstract: A power management device includes a control unit that controls a converter capable of bidirectionally converting between an external bus voltage and an internal bus voltage in a first power feeding system. When an amount of stored electric power of the first power feeding system is less than a first storage threshold value, the control unit sets a target value of the external bus voltage to a first power reception target value corresponding to a first transmission power value in a first power transmission request transmitted to an upper power management device. When the amount of stored electric power exceeds a second storage threshold value, the control unit sets the target value of the external bus voltage to a first power transmission target value corresponding to a second transmission power value in a second power transmission request received from a second power feeding system.

Abstract: An upper power management device includes: an update unit that updates a target value of interest based on a received power value of electric power received by a first power feeding system that is making a power transmission request, and a transmitted power value of electric power transmitted by a second power feeding system that is responding to the power transmission request, the target value of interest including at least one of a power reception target value of an external bus voltage in a first converter of the first power feeding system, and a power transmission target value of the external bus voltage in a second converter of the second power feeding system; and an output unit that outputs a first setting command for setting the power reception target value in the first converter and a second setting command for setting the power transmission target value in the second converter.

Abstract: The life of a plurality of storage batteries as a whole is increased. A DC power supplying system includes power conditioners that supply generated power generated at power generators to a DC bus, storage batteries, storage batteries that have a superior cycle characteristic, bidirectional DC/DC converters that perform power conversion between generated power supplied to the DC bus and charging power of the storage batteries, bidirectional DC/DC converters that perform power conversion between generated power and charging power of the second storage batteries, DC/DC converters that supply the generated power and the charging power to load appliances, and an energy management system that is operable when an absolute value of a power difference between the generated power and the load power supplied to the load appliances is equal to or greater than a power threshold to operate the DC converters.

Abstract: A power management device includes a control unit that switches an operation mode of a power feeding system by controlling a converter capable of bidirectionally converting between an internal bus voltage and an external bus voltage. The control unit sets the power feeding system to a power reception mode by setting a target value of the external bus voltage in the converter to a first target value when the amount of stored electric power is less than a first storage threshold value. The control unit sets the power feeding system to a power transmission mode by setting the target value to a second target value that is larger than the first target value when the amount of stored electric power exceeds a second storage threshold value that is larger than the first storage threshold value and a measured value of the external bus voltage exceeds a transmission threshold value.

Abstract: A power feeding system includes a direct current (DC) bus for supplying DC power, a renewable energy power generation device connected to the DC bus, a first converter connected to the DC bus and converting a bus voltage supplied to the DC bus into a load voltage supplied to a load device, a storage battery, a second converter provided between the storage battery and the DC bus and capable of bidirectionally converting the bus voltage and a battery voltage of the storage battery, and a power management device controlling the second converter to charge and discharge the storage battery. The power management device controls the second converter to change the bus voltage based on difference power obtained by subtracting load power supplied to the load device from supply power supplied to the DC bus, the supply power including generated power generated by the renewable energy power generation device.

Abstract: A DC power supply system includes: a DC bus serving as a bus bar for DC power supply; a natural energy power generator 30 that supplies generated power to the DC bus; a plurality of storage batteries that store the generated power from the natural energy power generator; a plurality of bidirectional DC-DC converters that connect the plurality of corresponding storage batteries to the DC bus; a power management apparatus that manages operations of the plurality of bidirectional DC-DC converters; and a target voltage corrector that calculates a correction value of a target value for the output voltage by using an average value of a plurality of actual measurement values of each output voltage of the bidirectional DC-DC converters. The power management apparatus individually controls the each output voltage of the bidirectional DC-DC converters by using each target value of the output voltages corrected based on the correction value.

Abstract: Fluctuations in the battery life of a plurality of storage batteries are reduced. A DC power supplying system includes power conditioners that supply generated power of power generators to a DC bus, converters that perform voltage conversion on a bus voltage and supply load power to load appliances, bidirectional converters that execute charging operations that charge storage batteries and discharging operations that discharge the storage batteries, and an energy management system that causes the converters to execute a charging operation when the generated power exceeds the load power and to execute a discharging operation when the generated power is below the load power. During a charging operation, the energy management system applies a first voltage-current characteristic that linearly increases the charging current in keeping with an increase in the bus voltage to each bidirectional DC/DC converter with a slope in keeping with the SOC of a storage battery.

Abstract: A power management device is a power management device that controls a temperature inside a housing in a power storage system that includes a power storage device including a storage battery and the housing for housing the power storage device. The power management device includes an acquisition unit that acquires status information indicating a status of the power storage system, a calculation unit that calculates a target temperature in the housing based on an allowable capacity deterioration rate of the storage battery, and an air volume control unit that controls an air volume of a fan provided in the housing based on the status information and the target temperature.

Abstract: An energy management system (controller) operates on a charging voltage Vba of a specified storage battery out of storage batteries to control power converting operations by bidirectional DC/DC converters. The energy management system controls the power converting operations of the respective bidirectional DC/DC converters so that the SOC of the specified storage battery is always higher than the SOCs of the other storage batteries, executes supplying of power from the other storage batteries to the DC bus with priority over supplying of power from the specified storage battery to the DC bus, and causes the corresponding bidirectional converters to stop the supplying of power from the other storage batteries the DC bus when the SOCs of the storage batteries have fallen below a lower limit value set in advance due to the supplying of power to the DC bus.

Abstract: A DC power supply system includes: a natural energy power generator connected to a DC bus through a first DC-DC converter; a load device connected to the DC bus through a second DC-DC converter; a storage battery connected to the DC bus through a third DC-DC converter and configured to be charged with a generated power when the generated power is larger than a load power and to be discharged to supply power to the load device when the generated power is smaller than the load power; and a power management apparatus that manages operations of the first to third DC-DC converters based on current power generation amount and load power amount, prediction values for future power generation amount and load power amount, a remaining capacity of the storage battery, preset target values for respective blackout rate, battery lifetime, and power suppression rate, and the priorities among the target values.

Abstract: A DC power supply system includes: a DC bus serving as a bus bar for DC power supply; a natural energy power generator 30 that supplies generated power to the DC bus; a plurality of storage batteries that store the generated power from the natural energy power generator; a plurality of bidirectional DC-DC converters that connect the plurality of corresponding storage batteries to the DC bus; a power management apparatus that manages operations of the plurality of bidirectional DC-DC converters; and a target voltage corrector that calculates a correction value of a target value for the output voltage by using an average value of a plurality of actual measurement values of each output voltage of the bidirectional DC-DC converters. The power management apparatus individually controls the each output voltage of the bidirectional DC-DC converters by using each target value of the output voltages corrected based on the correction value.

Abstract: A DC power supply system includes: a natural energy power generator connected to a DC bus through a first DC-DC converter; a load device connected to the DC bus through a second DC-DC converter; a storage battery connected to the DC bus through a third DC-DC converter and configured to be charged with a generated power when the generated power is larger than a load power and to be discharged to supply power to the load device when the generated power is smaller than the load power; and a power management apparatus that manages operations of the first to third DC-DC converters based on current power generation amount and load power amount, prediction values for future power generation amount and load power amount, a remaining capacity of the storage battery, preset target values for respective blackout rate, battery lifetime, and power suppression rate, and the priorities among the target values.

Abstract: The life of a plurality of storage batteries as a whole is increased. A DC power supplying system includes power conditioners that supply generated power generated at power generators to a DC bus, storage batteries, storage batteries that have a superior cycle characteristic, bidirectional DC/DC converters that perform power conversion between generated power supplied to the DC bus and charging power of the storage batteries, bidirectional DC/DC converters that perform power conversion between generated power and charging power of the second storage batteries, DC/DC converters that supply the generated power and the charging power to load appliances, and an energy management system that is operable when an absolute value of a power difference between the generated power and the load power supplied to the load appliances is equal to or greater than a power threshold to operate the DC converters.

Abstract: Fluctuations in the battery life of a plurality of storage batteries are reduced. A DC power supplying system includes power conditioners that supply generated power of power generators to a DC bus, converters that perform voltage conversion on a bus voltage and supply load power to load appliances, bidirectional converters that execute charging operations that charge storage batteries and discharging operations that discharge the storage batteries, and an energy management system that causes the converters to execute a charging operation when the generated power exceeds the load power and to execute a discharging operation when the generated power is below the load power. During a charging operation, the energy management system applies a first voltage-current characteristic that linearly increases the charging current in keeping with an increase in the bus voltage to each bidirectional DC/DC converter with a slope in keeping with the SOC of a storage battery.

Abstract: An energy management system (controller) operates on a charging voltage Vba of a specified storage battery out of storage batteries control power converting operations by bidirectional DC/DC converters. The energy management system controls the power converting operations of the respective bidirectional DC/DC converters so that the SOC of the specified storage battery is always higher than the SOCs of the other storage batteries, executes supplying of power from the other storage batteries to the DC bus with priority over supplying of power from the specified storage battery to the DC bus, and causes the corresponding bidirectional converters to stop the supplying of power from the other storage batteries the DC bus when the SOCs of the storage batteries have fallen below a lower limit value set in advance due to the supplying of power to the DC bus.

Abstract: The memory controller forms temporary virtual blocks each composed of a plurality of physical blocks, whose physical addresses are the same value, each of which is included in each of flash memories, extracts temporary virtual block to which at least one defective block belongs from the temporary virtual blocks, generates a second temporary virtual block to which a defective block does not belong by replacing a defective block belonging to one temporary virtual block with a normal block belonging to another temporary virtual block among temporary virtual blocks extracted, and allocates temporary virtual blocks not extracted and second temporary virtual blocks generated to available virtual blocks.

Abstract: In a case where at least one of physical blocks composing the virtual block becomes a defective block, use of the virtual block to which the defective block belongs is forbidden and the virtual block of which use is forbidden is managed as a defective virtual block. Replacing the defective block with a normal block is performed among the defective virtual blocks so as to generate the virtual block to which the defective block does not belong. Then use of the virtual block generated is allowed.

Abstract: When a free physical block where data is to be written is searched for, a search process for searching for a pair of free physical blocks is first executed using a free physical block search table. Detection of a free non-pair good block is executed only when a pair of free physical block is not detected in the search process using the free physical block search table. When there is a free physical block, two-plane write is executed. When there is no pair of free physical blocks, data is written in an adequately combined non-pair good blocks.

Abstract: In a case where at least one of physical blocks composing the virtual block becomes a defective block, use of the virtual block to which the defective block belongs is forbidden and the virtual block of which use is forbidden is managed as a defective virtual block. Replacing the defective block with a normal block is performed among the defective virtual blocks so as to generate the virtual block to which the defective block does not belong. Then use of the virtual block generated is allowed.