JP2022165653A - Power supply stabilization device - Google Patents

Abstract

To provide a power supply stabilization device using a secondary battery.SOLUTION: A power supply stabilization device connected between AC power and an electrical apparatus has a first converter whose AC side is connected to the AC power and converting AC into DC, a second converter whose AC side is connected to the electrical apparatus and converting DC into AC, an output measurement part measuring output voltage of the second converter, a terminal part capable of attaching/detaching a secondary battery, a switching device connected to a DC link connecting a DC side of the first converter and the DC side of the second converter, and switching whether or not power stored in the secondary battery attached to the terminal part is supplied to the DC link, a charging amount measurement part measuring a charging amount of the secondary battery attached to the terminal part, and a control part controlling the switching device based on a measurement result by the output measurement part and the charging amount measurement part.SELECTED DRAWING: Figure 1

Description

The present invention relates to a power stabilizing device.

Some electrical devices have large output fluctuations depending on how they are used, and large changes in rated voltage. For example, a welding machine or the like. If a power supply with a small or unstable output is used in such a device, the drop in output will result in deterioration of the marketability of the device.
Possible solutions to this problem include using an outlet near the primary power supply or increasing the output of the power supply. However, if it is necessary to use an outlet near the primary power source, the area in which the equipment can be used is limited. Also, increasing the output of the power supply may require a lot of expense.

In addition, there is a charger that is connected to an AC power supply and supplies a higher output out of the output of the AC power supply and the output of a built-in secondary battery (Patent Document 1).

JP 2004-304983 A

However, the charger described in Patent Document 1 is compatible with direct current and is not compatible with equipment using alternating current. In addition, the above charger does not take into consideration the fluctuation of the rated voltage.
SUMMARY OF THE INVENTION The present invention has been made in consideration of such circumstances, and one of its objects is to provide a stabilized power supply device using a secondary battery.

A power stabilizing device according to the present invention employs the following configuration.
(1): A power supply stabilizing device according to one aspect of the present invention includes a first converter connected between an AC power supply and an electric device, the AC side of which is connected to the AC power supply, and which converts AC to DC; side is connected to the electrical equipment, a second converter that converts direct current to alternating current, an output measurement unit that measures the output voltage of the second converter, a terminal part that can attach and detach a secondary battery, and the first It is connected to a DC link that connects the DC side of the converter and the DC side of the second converter, and switches whether to supply the power stored in the secondary battery attached to the terminal portion to the DC link. A control for controlling the switching device based on measurement results obtained by a switching device, a charge amount measuring unit that measures the charge amount of the secondary battery attached to the terminal unit, and the output measuring unit and the charge amount measuring unit. and

(2): In the aspect of (1) above, a secondary battery attached to the terminal portion is provided.

(3): In the aspect (1) or (2) above, the switching device is a DC/DC converter having one terminal connected to the terminal section, and the power stored in the secondary battery is transferred to the DC link. , the output voltage of the other terminal is made higher than the voltage of the DC link.

(4): In any one of the above aspects (1) to (3), a switch capable of changing the set voltage of the output of the second converter is provided, and the control unit controls the switching based on the set voltage. control the device.

(5): In any one of the above (1) to (4), the AC power supplied to the electrical device measured by the output measuring unit increases and approaches a predetermined power, and the charging amount When the charge amount of the secondary battery measured by the measurement unit is equal to or greater than a predetermined amount, the control unit controls the switching device so that power is supplied from the secondary battery to the second converter. make it

(6): In any one of the aspects (1) to (5) above, the first converter supplies direct current to the secondary battery, and the switching device switches from the first converter to the secondary battery. Regulates the power supplied to the battery.

(7): In any one of the aspects (1) to (6) above, when the charge amount measuring section cannot measure the charge amount of the secondary battery, the control section controls the second charge amount from the terminal section. The switching device is controlled such that no power is supplied to the converter and from the first converter to the terminals.

(8): In any one of the aspects (1) to (7) above, the output measurement unit detects whether or not the electrical device and the second converter are connected, and the output measurement unit and when detecting that the electric device and the second converter are not connected, the control unit controls the switching device so that power is supplied from the first converter to the secondary battery. do.

According to aspects (1) to (5), it is possible to suppress an increase in the voltage of the AC power supply by supplying power from the secondary battery based on the value of the output voltage and the amount of charge in the secondary battery. .
According to aspects (6) and (8), the secondary battery can be charged by supplying power from the AC power source to the secondary battery based on the value of the output voltage and the amount of charge in the secondary battery. .
According to the aspect (7), even if power cannot be supplied from the secondary battery, it is possible to supply substantially the same power as when connected to a normal AC power supply.

1 is a diagram showing a configuration of a power stabilizing device 1 according to a first embodiment; FIG. 4 is a flow chart showing the operation of the control unit 22 according to the first embodiment; It is an example of a timing chart when controlling the switching device 20 . It is a figure which shows the structure of the power supply stabilization apparatus 1 which concerns on 2nd Embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a power supply stabilizing device of the present invention will be described below with reference to the drawings.

[overall structure]
<First Embodiment>
FIG. 1 is a diagram showing the configuration of a power stabilizing device 1 according to the first embodiment.
The power supply stabilizing device 1 includes a first converter 10, a DC link 11, a second converter 12, an output measuring section 14, a DC link voltage measuring section 15, a charge amount measuring section 16, a terminal section 18, a secondary battery 19, A switching device 20 and a control unit 22 are provided. The power stabilizing device 1 has an input terminal and an output terminal. The input terminal is connected to the AC power supply 100 . The output terminals are connected to the electrical device 200 .

The first converter 10 converts AC power supplied from an AC power supply 100 via an input terminal into DC power, and supplies the DC power to the DC link 11 . The first converter 10 is, for example, an AC/DC converter. A DC link 11 connects the first converter 10 , the second converter 12 and the switching device 20 .

The second converter 12 converts the DC power supplied from the first converter 10 or the switching device 20 via the DC link 11 into AC power, and supplies the AC power to the electrical equipment 200 via the output terminal. The second converter 12 is for example a DC/AC inverter. The voltage of the power supplied by the second converter 12 to the electrical device 200 (hereinafter, set voltage) is not limited to the same voltage as the voltage of the power supplied by the AC power supply 100 . For example, when the AC power supply 100 supplies power with a voltage of 100V, the power stabilizing device 1 may supply power with a voltage of 200V to the electric device 200 .
Also, the set voltage may be changed by an external input. For example, the power stabilizing device 1 has a switch for setting the set voltage to 100 V or 200 V, and switching the switch changes the set voltage.

The output measurement unit 14 measures AC power supplied to the electrical device 200 . The output measuring unit 14 is provided, for example, between the second converter 12 and the electrical equipment 200 . The output measurement unit 14 includes, for example, a current sensor and a calculation unit. The calculator calculates the output power by multiplying the magnitude of the current measured by the current sensor by the set voltage of the second converter 12 . The output measurement unit 14 uses the result of the calculation by the calculation unit as the output power.

A DC link voltage measurement unit 15 measures the voltage of the DC link 11 with respect to ground.

The charge amount measuring section 16 measures the charge amount of the secondary battery 19 attached to the terminal section 18 . The secondary battery 19 is detachable from the terminal portion 18 and can be used repeatedly by being charged.

A switching device 20 is provided between the terminal portion 18 and the second converter 12 . The switching device 20 is, for example, a step-up/step-down DC/DC converter. The switching device 20 has a first terminal 31 and a second terminal 32 . The first terminal 31 is connected to the terminal portion 18 and the second terminal 32 is connected to the DC link 11 . The switching device 20 adjusts the voltage output from the first terminal 31 .
For example, the switching device 20 makes the voltage output to the second terminal 32 higher than the voltage of the DC link 11 (the output voltage of the first converter 10), so that the power is supplied from the secondary battery 19 to the DC link 11. be supplied.
Further, for example, the switching device 20 makes the voltage output to the second terminal 32 lower than the voltage of the DC link 11 (the output voltage of the first converter 10), so that the voltage from the secondary battery 19 to the DC link 11 is Prevent power from being supplied.

The control unit 22 measures the AC voltage measured by the output measurement unit 14, the charge amount of the secondary battery 19 attached to the terminal unit 18 measured by the charge amount measurement unit 16, and the DC link voltage measurement unit 15. The switching device 20 is controlled based on the voltage of the DC link 11 thus obtained. The control unit 22 is implemented, for example, by a hardware processor such as a CPU (Central Processing Unit) executing a program (software). Some or all of these components are hardware (circuit part; circuitry) or by cooperation of software and hardware. The program may be stored in advance in a storage device (a storage device with a non-transitory storage medium) such as a HDD (Hard Disk Drive) or flash memory, or may be stored in a removable storage such as a DVD or CD-ROM. It may be stored in a medium (non-transitory storage medium) and installed by loading the storage medium into a drive device.

For example, the control unit 22 determines that the charging amount of the secondary battery 19 attached to the terminal unit 18 is equal to or greater than a predetermined amount, and the power value measured by the output measuring unit 14 has increased and approached the power threshold value. At times, the switching device 20 is controlled so that power is supplied from the secondary battery 19 to the second converter 12 . The power threshold is, for example, the rated power of AC power supply 100 . The power supplied from the secondary battery 19 to the second converter 12 here changes according to the voltage of the DC link 11 .

FIG. 2 is a flow chart showing the operation of the control section 22 according to the first embodiment.
First, the control unit 22 determines whether or not the power value measured by the output measuring unit 14 is greater than the switching threshold (step S102). The switching threshold is a value less than the power threshold by a predetermined value (P ₁ ). For example, P1 is the power equivalent to ₁ % of the rated power. That is, in this embodiment, by determining whether the power value measured by the output measuring unit 14 is greater than the switching threshold value, it is possible to determine whether the power value has increased and approached the power threshold value. judge. If the output power is greater than the switching threshold, the control unit 22 determines whether or not the charge amount of the secondary battery 19 measured by the charge amount measuring unit 16 is greater than a predetermined amount (step S104). When the charge amount of the secondary battery 19 is larger than the predetermined amount, the controller 22 controls the switching device 20 so that the power of the secondary battery 19 is supplied to the second converter 12 (step S106).

The control unit 22 detects when the power value measured by the output measuring unit 14 is equal to or less than the switching threshold, or when the charge amount of the secondary battery 19 measured by the charge amount measuring unit 16 is equal to or less than a predetermined amount. At times, the switching device 20 may be controlled such that power from the secondary battery 19 is not supplied to the second converter 12 .

FIG. 3 is an example of a timing chart when the control unit 22 controls the switching device 20. As shown in FIG.
When the electric device 200 starts to be used, the AC power supplied to the electric device 200 increases. Since the output power is smaller than the switching threshold value ( _{a value smaller than the power threshold value by a predetermined value (P 1 )} ) until time T1, control unit 22 keeps switching device 20 OFF. do. When the output power reaches the switching threshold at time T1, control unit 22 controls switching device ₂₀ to moderate the increase in output power. As a result, the switching device 20 is turned on from off and starts to operate. Since the switching device 20 supplies power to the second converter 12 from the secondary battery 19 attached to the terminal portion 18, the output power is kept constant after a certain period of time after the switching device 20 is turned ON. Thresholds are prevented from being exceeded. Since power is supplied from the secondary battery ₁₉ after time T1, the charging rate of the secondary battery 19 decreases. Also, since power is supplied from the secondary battery ₁₉ after time T1, the output of the AC power supply 100 does not change or decreases.

As a result, when the power supplied to the electrical device 200 increases and reaches a value close to the power threshold value, the increase in the power supplied from the AC power supply 100 to the first converter 10 is suppressed, and the AC power supply It is possible to prevent the power supplied from 100 from exceeding the rated power.

<Second embodiment>
FIG. 4 is a diagram showing the configuration of the power stabilizing device 1 according to the second embodiment.
In addition to the control unit 22 according to the first embodiment, the control unit 22 according to the second embodiment includes the power value measured by the output measurement unit 14 and the terminal unit 18 measured by the charge amount measurement unit 16. The switching device 20 is controlled based on the charge amount of the secondary battery 19 mounted. For example, the control unit 22 switches when the charge amount of the secondary battery 19 attached to the terminal unit 18 is equal to or less than a predetermined amount and the power value measured by the output measurement unit 14 is smaller than a predetermined value. The device 20 is controlled so that power is supplied from the first converter 10 to the terminals 18 .

In the second embodiment, the power consumed by the electrical appliance 200 is less than the power that the AC power supply 100 can supply. The switching device 20 makes the voltage output from the second terminal 32 lower than the voltage of the DC link 11 so that power is supplied from the first converter 10 to the terminal section 18 .

As a result, when the output to the electrical device 200 is low and the amount of charge in the secondary battery 19 is low, power is supplied to the terminal portion 18 and the secondary battery 19 can be charged. Therefore, it is not necessary to take out the secondary battery 19 and charge it.

<Other embodiments>
Although the output measurement unit 14 calculates the power value from the current value, the present invention is not limited to this. The output measurement unit 14 may, for example, measure a value of current, and the control unit 22 may control the switching device 20 based on the measured value of current. The output measuring unit 14 may measure both the current value and the voltage value to calculate the power.

When the charge amount measurement unit 16 cannot measure the charge amount of the secondary battery 19 attached to the terminal unit 18, the control unit 22 prevents power from being supplied from the terminal unit 18 to the second converter 12 and the first The switching device 20 may be controlled so that power is not supplied from the converter 10 to the terminals 18 . When the charge amount measuring unit 16 cannot measure the charge amount of the secondary battery 19 attached to the terminal unit 18, for example, the secondary battery 19 is removed from the terminal unit 18 or attached to the terminal unit 18. This is when the secondary battery 19 is out of order. Under the control of the switching device 20 by the controller 22 , the power supplied from the AC power source 100 is converted by the first converter 10 , converted by the second converter 12 , and supplied to the electrical equipment 200 . In other words, substantially the same power as that supplied from AC power supply 100 is supplied to electric device 200 .

The power stabilizing device 1 may have a function of determining whether or not the secondary battery 19 is attached to the terminal portion 18 . When it is determined that the secondary battery 19 has been removed from the terminal section 18, the control section 22 controls the switching device 20 so that the power supplied from the AC power supply 100 is converted by the first converter 10 and converted to the second It is converted by the converter 12 and supplied to the electrical equipment 200 .

When the output measuring unit 14 cannot measure the power supplied to the electric device 200, the control unit 22 controls the switching device 20 so that the power is supplied from the first converter 10 to the terminal unit 18. good. When the output measuring unit 14 cannot measure the power supplied to the electric device 200 , the electric device 200 is not connected to the second converter 12 , for example. Under the control of the switching device 20 by the controller 22 , power supplied from the AC power source is converted by the first converter 10 , converted by the switching device 20 , and supplied to the terminal section 18 . As a result, the secondary battery 19 attached to the terminal portion 18 is charged with power supplied from the AC power supply 100 .

Moreover, the power stabilizing device 1 may have a function of determining whether or not the electric device 200 is connected to the power stabilizing device 1 . When it is determined that the electrical equipment 200 is not connected to the power stabilizing device 1, the control unit 22 controls the switching device 20 so that power is supplied from the first converter 10 to the secondary battery 19. .

As described above, the mode for carrying out the present invention has been described using the embodiments, but the present invention is not limited to such embodiments at all, and various modifications and replacements can be made without departing from the scope of the present invention. can be added.

1 Power Supply Stabilizing Device 10 First Converter 11 DC Link 12 Second Converter 14 Output Measuring Section 16 Charge Measuring Section 18 Terminal Section 19 Secondary Battery 20 Switching Device 22 Control Section 31 First Terminal 32 Second Terminal 100 AC Power supply 200 Electric equipment

Claims (8)

A power stabilizing device connected between an AC power supply and an electrical device,
a first converter whose AC side is connected to the AC power supply and converts AC to DC;
a second converter whose AC side is connected to the electrical equipment and converts direct current to alternating current;
an output measuring unit that measures the output voltage of the second converter;
a terminal section to which a secondary battery can be attached and detached;
Whether the power stored in the secondary battery connected to the DC link connecting the DC side of the first converter and the DC side of the second converter and attached to the terminal portion is supplied to the DC link a switching device for switching between
a charge amount measuring unit that measures the charge amount of the secondary battery attached to the terminal unit;
a control unit that controls the switching device based on the measurement results of the output measurement unit and the charge amount measurement unit;
power stabilizer. a secondary battery attached to the terminal portion;
The power stabilizing device according to claim 1, comprising: When the switching device is a DC/DC converter having a first terminal connected to the terminal unit and a second terminal connected to the DC link, the electric power stored in the secondary battery is supplied to the DC link. , making the output voltage of the second terminal higher than the voltage of the DC link;
The power stabilizing device according to claim 1 or 2. A switch capable of changing the set voltage output by the second converter,
The control unit controls the switching device based on the set voltage.
The power stabilizing device according to any one of claims 1 to 3. AC power supplied to the electrical device measured by the output measuring unit increases and approaches a predetermined power,
When the charge amount of the secondary battery measured by the charge amount measuring unit is equal to or greater than a predetermined amount,
The control unit controls the switching device so that power is supplied from the secondary battery to the second converter.
The power stabilizing device according to any one of claims 1 to 4. the value of the AC power supplied to the electrical device measured by the output measuring unit is smaller than a predetermined power;
When the charge amount of the secondary battery measured by the charge amount measuring unit is equal to or less than a predetermined amount,
The control unit controls the switching device so that power is supplied from the DC link to the secondary battery.
The power stabilizing device according to any one of claims 1 to 5. When the charge amount measuring unit cannot measure the charge amount of the secondary battery,
The control unit controls the switching device so that power is not supplied from the terminal unit to the second converter and from the first converter to the terminal unit.
The power stabilizing device according to any one of claims 1 to 6. The output measuring unit detects whether the electrical device and the second converter are connected,
When the output measurement unit detects that the electrical device and the second converter are not connected,
The control unit controls the switching device so that power is supplied from the first converter to the secondary battery.
The power stabilizing device according to any one of claims 1 to 7.

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