Granted Patent B2

US 12,732,015 · App. 18/675,394 · Granted Sep 8, 2026

Inventor: Tetsu Shijo (Tokyo, JP)

Assignee: KABUSHIKI KAISHA TOSHIBA

H02J9/062H02J3/32H02J7/82H02J7/933H02J2207/20

Abstract

Claims (40)

1 . An uninterruptible power supply connectable to a power line via which electric power from a power grid is supplied to a load device, comprising:

a storage battery that is chargeable/dischargeable;

a monitor configured to monitor a state of charge of the storage battery; and

a controller configured to control charging the storage battery from the power line and discharging from the storage battery to the power line, based on the state of charge of the storage battery and a difference between a first frequency which is an operation frequency of the power grid and a second frequency which serves as a reference operation frequency for the power grid,

wherein the controller selects, from among a plurality of charge/discharge patterns in which the difference is associated with a charge/discharge power value to the power line, a charge/discharge pattern according to the state of charge of the storage battery, and controls charging and discharging of the storage battery based on the selected charge/discharge pattern and the difference, and

wherein the controller selects a first charge/discharge pattern when the state of charge is equal to or greater than a first threshold, and selects a second charge/discharge pattern when the state of charge is less than the first threshold.

2 . The uninterruptible power supply according to claim 1 , wherein:

the first charge/discharge pattern specifies charging power whose value increases with increasing difference when the difference is greater than a first predetermined value, and specifies discharging power whose value increases with decreasing difference when the difference is less than the first predetermined value,

the second charge/discharge pattern specifies charging power whose value increases with increasing difference when the difference is greater than a second predetermined value, and specifies discharging power whose value increases with decreasing difference when the difference is less than the second predetermined value, and

the first predetermined value is greater than the second predetermined value.

3 . The uninterruptible power supply according to claim 1 , wherein the second charge/discharge pattern specifies charging power whose value increases with increasing difference when the difference is greater than a third predetermined value, and specifies discharging power whose value is zero when the difference is less than the third predetermined value.

4 . The uninterruptible power supply according to claim 1 , wherein the controller selects a third charge/discharge pattern when the state of charge is equal to or greater than a second threshold, and the second threshold is greater than the first threshold.

5 . The uninterruptible power supply according to claim 4 , wherein:

the first charge/discharge pattern specifies charging power whose value increases with increasing difference when the difference is greater than a first predetermined value, and specifies discharging power whose value increases with decreasing difference when the difference is less than the first predetermined value,

the third charge/discharge pattern specifies charging power whose value increases with increasing difference when the difference is greater than a fourth predetermined value, and specifies discharging power whose value increases with decreasing difference when the difference is less than the fourth predetermined value, and

the fourth predetermined value is greater than the first predetermined value.

6 . The uninterruptible power supply according to claim 4 , wherein the third charge/discharge pattern specifies charging power of zero when the difference is greater than a fifth predetermined value, and specifies discharging power whose value increases with decreasing difference when the difference is less than the fifth predetermined value.

7 . The uninterruptible power supply according to claim 1 , wherein the state of charge is a ratio of an amount of electricity stored in the storage battery to a capacity of the storage battery.

8 . An uninterruptible power supply connectable to a power line via which electric power from a power grid is supplied to a load device, comprising:

a storage battery being chargeable/dischargeable;

a monitor configured to monitor a state of charge of the storage battery;

a controller configured to control charging the storage battery from the power line and discharging from the storage battery to the power line, based on the state of charge of the storage battery and a difference between a first frequency being operation frequency of the power grid and a second frequency serving as a reference operation frequency for the power grid; and

a timer configured to start counting a first period of time when the operation frequency of the power grid falls below a threshold,

wherein the controller discharges the storage battery during the first period of time, and when the timer detects that the first period of time has elapsed, stops an AC/DC converter provided between the power grid and the load device to stop the discharging of the storage battery.

9 . A power system comprising:

a first uninterruptible power supply and a second uninterruptible power supply, each of which comprises the uninterruptible power supply according to claim 1 ,

wherein the first uninterruptible power supply has a priority higher than that of the second uninterruptible power supply, and

wherein charging/discharging of the second uninterruptible power supply is prioritized over charging/discharging of the first uninterruptible power supply when the difference between the first frequency and the second frequency is within a first range with respect to the second frequency.

10 . The power system according to claim 9 , wherein the first uninterruptible power supply is not charged or discharged when the difference is within the first range.

11 . The power system according to claim 9 , wherein the storage battery of the first uninterruptible power supply is a storage battery of a first type, and the storage battery of the second uninterruptible power supply is a storage battery of a second type that is different from the first type.

12 . A control device which controls an uninterruptible power supply connectable to a power line via which electric power from a power grid is supplied to a load device, comprising:

a monitor configured to monitor a state of charge of a storage battery in the uninterruptible power supply; and

a controller configured to control charging the storage battery from the power line and discharging from the storage battery to the power line, based on the state of charge of the storage battery and a difference between a first frequency which is an operation frequency of the power grid and a second frequency which serves as a reference operation frequency for the power grid,

wherein the controller selects, from among a plurality of charge/discharge patterns in which the difference is associated with a charge/discharge power value to the power line, a charge/discharge pattern according to the state of charge of the storage battery, and controls charging and discharging of the storage battery based on the selected charge/discharge pattern and the difference, and

wherein the controller selects a first charge/discharge pattern when the state of charge is equal to or greater than a first threshold, and selects a second charge/discharge pattern when the state of charge is less than the first threshold.

13 . A control method which controls an uninterruptible power supply connectable to a power line via which electric power from a power grid is supplied to a load device, comprising:

monitoring a state of charge of a storage battery in the uninterruptible power supply; and

controlling charging the storage battery from the power line and discharging from the storage battery to the power line, based on the state of charge of the storage battery and a difference between a first frequency which is an operation frequency of the power grid and a second frequency which serves as a reference operation frequency for the power grid,

wherein the controlling comprises selecting, from among a plurality of charge/discharge patterns in which the difference is associated with a charge/discharge power value to the power line, a charge/discharge pattern according to the state of charge of the storage battery, and controlling charging and discharging of the storage battery based on the selected charge/discharge pattern and the difference, and

wherein the controlling selects a first charge/discharge pattern when the state of charge is equal to or greater than a first threshold, and selects a second charge/discharge pattern when the state of charge is less than the first threshold.

Assignments (1)

Priority Claims (1)

Continuity (1)

References Cited (23)