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: 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 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: A standalone direct current (DC) power supplying system, which is not connected to commercial power, includes a power conditioner that supplies generated power W2 of a power generator to a DC bus, DC/DC converters that convert a bus voltage Vbs and supply load power (WLa+WLb) to load appliances, bidirectional DC/DC converters that supply a constant DC current from the DC bus to storage batteries or from the storage batteries to the DC bus, and an energy management system. When the generated power W2 exceeds the load power (WLa+WLb), the energy management system causes the converters to supply a constant DC current with a common charging rate to the storage batteries, and when the generated power W2 falls below the load power (WLa+WLb), the energy management system causes the converters to supply a constant DC current with a common discharging rate from the storage batteries to the DC bus.

Abstract: Fluctuations in the lives of a plurality of storage batteries are reduced. A DC power supplying system includes a power conditioner that supplies generated power W2 of a power generator to a DC bus, DC/DC converters that convert a bus voltage Vbs and supply load power (WLa+WLb) to load appliances, bidirectional DC/DC converters that supply a constant DC current from the DC bus to storage batteries or from the storage batteries to the DC bus, and an energy management system. When the generated power W2 exceeds the load power (WLa+WLb), the energy management system causes the converters to supply a constant DC current with a common charging rate to the storage batteries and when the generated power W2 falls below the load power (WLa+WLb), the energy management system causes the converters to supply a constant DC current with a common discharging rate from the storage batteries to the DC bus.