JP3267549B2 - Power supply switching method of uninterruptible power supply and uninterruptible power supply - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an uninterruptible power supply, and more particularly to a power supply switching operation of the uninterruptible power supply.

[0002]

2. Description of the Related Art Conventionally, an uninterruptible power supply that switches power supply to an exchange device from power supply by an AC power supply to power supply by a storage battery power supply when an AC power supply fails is provided with an input voltage monitoring circuit. In the input voltage monitoring circuit, the voltage of the AC power supply is constantly monitored,
When the voltage of the AC power supply becomes equal to or lower than a predetermined value, it is determined that the AC power supply has stopped, and the power supply to the switching device is switched from the AC power supply to the storage battery power supply.

For example, as a condition for detecting a voltage drop such as a fuel drop of a generator, when the AC power supply voltage becomes 95 V or less, it is regarded as a power failure, and power is supplied to the exchange device by inverter power supply from a storage battery power supply.

[0004]

In an AC power supply device using a motor such as a generator, reliability may be reduced due to aging or use environment conditions. It is possible to cause a state in which a voltage around 95 V is still supplied.

[0005] In this case, in the switching device, a voltage of about 90 V is supplied to the input side even if the voltage drop (about 5 V) in the fixed-length power cable is taken into consideration. It is not the input voltage range that causes trouble.

However, in the above-described conventional uninterruptible power supply, when the AC power supply voltage becomes 95 V or less, it is regarded as a power outage, and power is supplied to the exchange device by inverter power supply from the storage battery power supply. However, even though the AC power supply is not a power failure, and the input voltage of the replacement device does not hinder the operation, power may be supplied from the storage battery power supply. And the maintenance person frequently charges the storage battery power supply, which requires a great deal of labor for maintenance of the uninterruptible power supply.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and can reduce the consumption of the storage battery power supply and can reduce the frequency with which the maintenance person charges the storage battery power supply. It is an object of the present invention to provide an uninterruptible power supply capable of reducing the power consumption.

[0008]

To achieve the above object, the present invention provides an input means to which an AC voltage is input, and converts an AC voltage input through the input means into a DC voltage and outputs the DC voltage. A rectifier circuit, a storage battery circuit charged with the DC voltage output from the rectifier circuit, and converting the DC voltage output from the rectifier circuit or the DC voltage charged in the storage battery circuit into a stable AC voltage. An inverter circuit for outputting, and a switching circuit for outputting one of an AC voltage input through the input means and an AC voltage output from the inverter circuit based on a predetermined condition; A power supply switching method for an uninterruptible power supply device, comprising: a control circuit that controls an operation of the switching circuit based on the switching circuit; When the AC voltage input through the input means is higher than a predetermined first reference voltage, the AC voltage input through the input means is output as it is, and the AC voltage input through the input means is output through the input means. When the input AC voltage is equal to or lower than the first reference voltage and higher than a second reference voltage having a value lower than the first reference voltage, the AC voltage input via the input unit is changed to Output through the rectifier circuit and the inverter circuit, when the AC voltage input through the input means is equal to or less than the second reference voltage, the voltage charged in the storage battery circuit through the inverter circuit It is characterized by outputting.

Further, input means for inputting an AC voltage,
A rectifier circuit that converts an ac voltage input through the input means into a dc voltage and outputs the dc voltage; a storage battery circuit charged with the dc voltage output from the rectifier circuit; and a dc voltage output from the rectifier circuit. Alternatively, an inverter circuit that converts a DC voltage charged in the storage battery circuit into a stable AC voltage and outputs the converted AC voltage, and outputs any one of an AC voltage input through the input unit and an AC voltage output from the inverter circuit. A switching circuit that outputs one of them based on a predetermined condition, a control circuit that controls the operation of the switching circuit based on the predetermined condition, and an output unit that outputs an AC voltage output from the switching circuit to the outside in the uninterruptible power supply comprising a preparative, the control circuit compares the AC voltage inputted through the input means with a first reference voltage to a predetermined, pre-filled AC voltage input via the means
When the voltage is higher than the first reference voltage,
The input AC voltage is supplied to the output means as it is.
The switching circuit is controlled so that the
If the input AC voltage is less than or equal to the first reference voltage,
Start the inverter circuit and
The AC voltage output from the inverter circuit is supplied to the output means.
A first voltage comparison circuit that controls the switching circuit so as to be supplied, a second reference voltage lower than the first reference voltage, and an AC voltage input through the input means, The AC voltage input via the input means is
2, the operation of the rectifier circuit is stopped.
And a second voltage comparison circuit.

[0010]

[0011]

In addition, whether or not the AC voltage input through the input means is output as it is, whether or not the inverter circuit is activated, and whether or not the voltage charged in the storage battery circuit is output A display circuit for indicating whether or not the display circuit is provided.

[0013] The display circuit indicates a state of charge of the storage battery circuit.

(Operation) In the present invention configured as described above, if the AC voltage input via the input means is higher than the first reference voltage predetermined, the input is performed via the input means. If the AC voltage input through the input means is lower than the first reference voltage and higher than the second reference voltage having a value lower than the first reference voltage, The AC voltage input via the means is converted into a stable AC voltage and output. If the AC voltage input via the input means is equal to or lower than the second reference voltage, the voltage charged in the storage battery circuit is reduced. Is output.

As described above, even when the AC voltage input via the input means decreases and becomes equal to or lower than the predetermined first reference voltage, the AC voltage is equal to or lower than the first reference voltage and equal to or lower than the first reference voltage. If the voltage is higher than the second reference voltage having a value lower than the first reference voltage, the voltage charged in the storage battery circuit will not be output, so that the consumption of the storage battery power is reduced and the maintenance person can use the storage battery. The frequency of charging the power supply is reduced.

Here, the second reference voltage is set to a value that does not hinder the operation of the switching device connected to the output side.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of an uninterruptible power supply according to the present invention.

In this embodiment, as shown in FIG. 1, an input section 210 to which an AC voltage is input, and a rectifier circuit 2 which converts an AC voltage input through the input section 210 into a DC voltage and outputs the DC voltage.
20 and the rectifier circuit 22
The storage battery circuit 230 in which the voltage converted to the DC voltage at 0 is charged, the charging circuit 240 in which the DC voltage output from the rectification circuit 220 is charged to the storage battery circuit 230, the DC voltage output from the rectification circuit 220 or Storage battery circuit 23
An inverter circuit 250 that converts a DC voltage charged to 0 into a stable AC voltage and outputs the converted AC voltage, an output unit 260 that supplies a voltage to an external switching device (not shown), and an output unit 260 The voltage to be output to the outside is
0 and the inverter circuit 250
And a rectifier circuit 220 and an inverter circuit 250 based on the AC voltage input through the input unit 210.
And a control circuit 280 for controlling the operation of the switching circuit 270.

The switching circuit 270 includes an input unit 210
AC voltage input through the output unit 2
60, an AC switch 272 that supplies the AC voltage output from the inverter circuit 250 to the output unit 260, and an AC switch 271 and 272 based on the AC voltage input through the input unit 210. A changeover switch 273 for controlling the operation is provided, and a control circuit 280 has a 95V voltage setting circuit 281 in which a voltage of 95V which is a predetermined first reference voltage value is set, and a predetermined voltage. 9 which is the second reference voltage value
A 92 V voltage setting circuit 282 set to a voltage of 2 V;
A first voltage comparison circuit that compares the 95V voltage in the 95V voltage setting circuit 281 with the AC voltage input via the input unit 210 and controls the operation of the changeover switch 273 and the inverter circuit 250 based on the comparison result. 283
And a 92V voltage in the 92V voltage setting circuit 282 and an AC voltage input via the input unit 210, and
A second voltage comparison circuit 284 for controlling the operation of the rectifier circuit 220 based on the comparison result is provided.

Hereinafter, the operation of the uninterruptible power supply configured as described above will be described. In the present embodiment, when the AC voltage input to the uninterruptible power supply exceeds 95 V, the output voltage is abnormal due to a failure of the AC generator or a decrease in fuel when the AC voltage exceeds 95 V and is 95 or less. The abnormal state in which the voltage is reached, and the case where the voltage is equal to or lower than 92 V is regarded as a power failure state.

FIG. 2 is a diagram for explaining the operation of the uninterruptible power supply shown in FIG. 1. FIG. 2 (a) shows a case where the AC voltage input through the input unit 210 exceeds 95V. FIG. 2B is a diagram for explaining the operation, FIG. 2B is a diagram for explaining the operation when the AC voltage input via the input unit 210 exceeds 92 V and is 95 V or less, and FIG.
FIG. 7 is a diagram for explaining an operation when an AC voltage input via the IC is 92 V or less. FIG. 3 is a block diagram showing an example in which an AC generator is connected to the input side of the uninterruptible power supply shown in FIG. 1 and a switching device is connected to the output side.

The AC voltage generated by AC generator 100 is input to input section 210 of uninterruptible power supply 200 via power supply line 400.

Here, the AC generator 100 is installed outdoors and has fixed-length power cables 500a and 500b.
A power supply device for supplying necessary AC power to the exchange device 300 which is separately installed via the
The output voltage of the generator is set high beforehand so that the input power supply condition of the exchange device 300 can be met in anticipation of the voltage drop at 0a and 500b.

When an AC voltage is input to the input unit 210,
In the voltage comparison circuit 283 in the control circuit 280, the AC voltage input via the input unit 210 is compared with the voltage of 95 V in the 95 V voltage setting circuit 281, and in the voltage comparison circuit 284 in the control circuit 280,
The AC voltage input via the input unit 210 is compared with the 92V voltage in the 92V voltage setting circuit 282.

The operation will be described below for each of the levels of the AC voltage input through the input section 210.

(1) When the Input AC Voltage Exceeds 95 V (Normal State) When the AC voltage input via the input unit 210 exceeds 95 V, the voltage is input to the voltage comparison circuit 283. It is determined that the AC voltage exceeds 95 V, and the changeover switch 273 is controlled, whereby the AC switch 2
71 is set to the conducting state, and the AC switch 272 is set to the non-conducting state. In this case, the voltage comparison circuit 28
3 does not output a control signal for activating the inverter circuit 250, and the inverter circuit 250 does not activate.

Further, in the voltage comparison circuit 284, it is determined that the input AC voltage exceeds 92 V, and no control signal for stopping the operation of the rectification circuit 220 is output from the voltage comparison circuit 284, and the rectification circuit 220 is in operation.

Then, the AC voltage input via the input unit 210 is supplied directly to the output unit 260 via the AC switch 271 as it is.

The AC voltage supplied to the output unit 260 is supplied to fixed-length power cables 500a and 500b connected in multiple stages.
Is output to the switching device 300 via the.

At this time, the AC voltage input through the input section 210 is converted into a DC voltage in the rectifier circuit 220 and charged in the storage battery circuit 230 by the charging circuit 240.

(2) When the input AC voltage exceeds 92 V and is 95 V or less (abnormal state) When the AC voltage input via the input unit 210 exceeds 92 V and is 95 V or less, the voltage comparison circuit 283 It is determined that the input AC voltage is 95 V or less, and the changeover switch 273 is controlled, whereby the AC switch 271 is set to the non-conducting state and the AC switch 272 is set to the conducting state, respectively. A control signal for activating the inverter circuit 250 is output from 283, and the inverter circuit 250 is activated.

Further, in the voltage comparison circuit 284, it is determined that the input AC voltage exceeds 92 V, and a control signal for stopping the operation of the rectification circuit 220 is not output from the voltage comparison circuit 284, so that the rectification circuit 220 is in operation.

Then, the AC voltage input through the input unit 210 is converted into a DC voltage in the rectifier circuit 220, and the DC voltage is converted into a stable AC voltage in the inverter circuit 250, and is converted through the AC switch 272. And is supplied to the output unit 260.

The AC voltage supplied to the output unit 260 is supplied to fixed-length power cables 500a and 500b connected in multiple stages.
Is output to the switching device 300 via the.

At this time, the AC voltage input via the input unit 210 is converted into a DC voltage in the rectifier circuit 220, and the storage battery circuit 230 is charged by the charging circuit 240.

(3) When the input AC voltage is 92 or less (power failure state) When the AC voltage input through the input unit 210 is 92 V or less, the input AC voltage is 95 V in the voltage comparison circuit 283. The changeover switch 27
3 is controlled, whereby the AC switch 271 is set to the non-conducting state and the AC switch 272 is set to the conducting state, and a control signal for starting the inverter circuit 250 is output from the voltage comparison circuit 283, and the inverter The circuit 250 starts.

Further, in the voltage comparison circuit 284, it is determined that the input AC voltage is 92 V or less, and a control signal for stopping the operation of the rectification circuit 220 is output from the voltage comparison circuit 284. Operation stops.

Then, the AC voltage input through the input unit 210 is not output from the rectifier circuit 220, but instead the DC voltage charged in the storage battery circuit 230 is output. The voltage is converted to a voltage, and the output
0 is supplied.

The AC voltage supplied to the output unit 260 is supplied to fixed-length power cables 500a and 500b connected in multiple stages.
Is output to the switching device 300 via the.

(4) When the power is restored from the power failure state to the normal state When the AC voltage input via the input unit 210 is restored to the normal voltage, the voltage comparison circuit 283 converts the input AC voltage to the normal voltage. It is determined that the voltage exceeds 95 V, and the voltage comparison circuit 284 determines that the input AC voltage exceeds 92 V.
3, 284, a voltage monitoring circuit (not shown) is reset.

Thereafter, the control signal for starting the inverter circuit 250 is no longer output from the voltage comparison circuit 283, and the voltage comparison circuit 284
The control signal for stopping the operation of 0 is not output.

Also, the changeover switch 273 is controlled,
Thereby, AC switch 271 is set to the conductive state, and AC switch 272 is set to the non-conductive state.

As a result, the AC voltage input via the input unit 210 is supplied directly to the output unit 260 via the AC switch 271 as it is.

(Other Embodiments) FIG. 4 is a block diagram showing another embodiment of the uninterruptible power supply according to the present invention.

In this embodiment, as shown in FIG. 4, an input section 210 to which an AC voltage is input, and a rectifier circuit 2 for converting an AC voltage input through the input section 210 into a DC voltage and outputting the DC voltage.
20 and the rectifier circuit 22
The storage battery circuit 230 in which the voltage converted to the DC voltage at 0 is charged, the charging circuit 240 in which the DC voltage output from the rectification circuit 220 is charged to the storage battery circuit 230, the DC voltage output from the rectification circuit 220 or Storage battery circuit 23
An inverter circuit 250 that converts a DC voltage charged to 0 into a stable AC voltage and outputs the converted AC voltage, an output unit 260 that supplies a voltage to an external switching device (not shown), and an output unit 260 The voltage to be output to the outside is
0 and the inverter circuit 250
And a rectifier circuit 220 and an inverter circuit 250 based on the AC voltage input through the input unit 210.
And a control circuit 280 for controlling the operation of the switching circuit 270
And a display circuit 290 indicating a power path of the AC voltage supplied to the output unit 260.

The switching circuit 270 and the control circuit 280
Is similar to that shown in FIG.

In the display circuit 290, the first connection terminal VI connected to the input section 210 and the output section 26
0 and a second connection terminal VO connected to the AC switch 2
A third connection terminal DPS connected to the output terminal 71;
Fourth connection terminal IN to which a control signal for starting inverter circuit 250 from voltage comparison circuit 283 is input.
V, a fifth connection terminal RECT to which a control signal for stopping the operation of the rectifier circuit 220 from the voltage comparison circuit 284 is input, and a sixth connection terminal BATT connected to the output terminal of the electric storage circuit 230 Are provided.

Hereinafter, the operation of the uninterruptible power supply circuit configured as described above will be described for each level of the AC voltage input via the input unit 210. Note that operations other than the display circuit 290 are the same as those described in the above-described embodiment, and a description thereof will not be repeated.

FIG. 5 is a diagram for explaining the operation of the display circuit 290 shown in FIG. 4. FIG. 5A shows the operation when the AC voltage input via the input unit 210 exceeds 95V. (B) is a diagram for explaining the operation when the AC voltage input through the input unit 210 exceeds 92 V and is 95 V or less, and (c) is a diagram for explaining the operation of the input unit 210.
FIG. 7 is a diagram for explaining an operation when an AC voltage input via the IC is 92 V or less. In the drawing, the shaded portions indicate that the display is on, and the unpainted portions indicate that the display is off. In addition, the display of the storage battery indicates the state of charge of the storage battery, which means that the “F” side is in a fully charged state.

(1) When the Input AC Voltage Exceeds 95 V (Normal State) First, when an AC voltage is input through the input unit 210,
The AC voltage is input to the connection terminal VI connected to the input unit 210, and the display portion of the AC input lights up.

When the AC voltage input through the input unit 210 exceeds 95 V, the AC switch 271 is turned on, so that the AC voltage is input to the connection terminal DPS connected to the output terminal of the AC switch 271. Then, the display part of the direct sending lights up.

Since the control signal for activating the inverter circuit 250 is not output from the voltage comparison circuit 283, the display portions of the inverter and the storage battery are turned off.

When the storage battery circuit 230 is charged with the AC voltage, the display portion of the storage battery is lit, and as the battery is charged, the lit portion increases in the direction of "F" in the figure.

Since the AC voltage is supplied to the output section 260, the AC voltage is input to the connection terminal VO connected to the output section 260, and the display portion of the AC output lights up.

(2) When the input AC voltage exceeds 92 V and is 95 V or less (abnormal state) First, when an AC voltage is input through the input unit 210,
The AC voltage is input to the connection terminal VI connected to the input unit 210, and the display portion of the AC input lights up.

When the AC voltage input via the input unit 210 exceeds 92 V and is 95 V or less, the voltage comparison circuit 2
Since the control signal for activating the inverter circuit 250 is output from 83, the control signal for activating the inverter circuit 250 is input to the connection terminal INV of the display circuit 290, and the display portion of the inverter is turned on.

Further, since the AC switch 271 is turned off, no AC voltage is input to the connection terminal DPS connected to the output terminal of the changeover switch 271, and the display portion for direct transmission is turned off.

Further, the rectifier circuit 2
Since the control signal for stopping the operation of the inverter 20 has not been output, the inverter circuit 250
, No DC voltage is supplied to the connection terminal BATT connected to the output terminal of the storage battery circuit 250, and the display portion of the storage battery is turned off.

When the storage battery circuit 230 is charged with the AC voltage, the display portion of the storage battery is lit. As the battery is charged, the lit portion increases in the direction of "F" in the figure.

Since the AC voltage is supplied to the output section 260, the AC voltage is input to the connection terminal VO connected to the output section 260, and the display portion of the AC output lights up.

(3) When the input AC voltage is 92 or less (power failure state) First, when an AC voltage is input through the input unit 210,
The AC voltage is input to the connection terminal VI connected to the input unit 210, and the display portion of the AC input lights up.

When the AC voltage input through the input unit 210 is 92 V or less, a control signal for starting the inverter circuit 250 is output from the voltage comparison circuit 283, so that the connection terminal INV of the display circuit 290 is , A control signal for activating the inverter circuit 250 is input, and the display portion of the inverter is turned on.

Further, the rectifier circuit 2
Since a control signal for stopping the operation of the battery 20 is output, a DC voltage is supplied from the storage battery circuit 230 to the inverter circuit 250, and a DC voltage is input to the connection terminal BATT connected to the output terminal of the storage battery circuit 250, The display of the storage battery lights up.

Further, since the AC switch 271 is turned off, no AC voltage is input to the connection terminal DPS connected to the output terminal of the AC switch 271 and the display portion for direct transmission is turned off.

Further, since the charged voltage is output to the storage battery circuit 230, the lighting portion at the display location of the storage battery gradually decreases.

As described above, in the present embodiment, it is determined whether or not the AC voltage input via the input unit 210 is directly output and output via the inverter circuit 250. Whether or not the voltage charged in the circuit 230 is output is displayed in the form of a route diagram, and the state of charge of the storage battery circuit 230 is displayed in the form of a bar.

In the above-described embodiment, a normal state is set when the AC voltage input to the uninterruptible power supply exceeds 95 V, and a failure of the AC generator or a decrease in fuel occurs when the AC voltage exceeds 92 V and equal to or less than 95. Accordingly, the abnormal state in which the output voltage has become an abnormal voltage, and the case where the output voltage is 92 V or less are respectively set as the power failure state. However, the present invention is not limited to this. It is possible to

[0069]

Since the present invention is constructed as described above, it has the following effects.

In the first to fourth aspects,
If the AC voltage input through the input means is higher than a predetermined first reference voltage, the AC voltage input through the input means is output as it is, and the AC voltage input through the input means is output. Is less than or equal to a first reference voltage and the first
When the voltage is higher than the second reference voltage having a value lower than the reference voltage, the AC voltage input through the input means is converted into a stable AC voltage and output, and the AC voltage input through the input means is output. When the voltage is equal to or lower than the second reference voltage, the voltage charged in the storage battery circuit is output, and the AC voltage input through the input means is used to detect the failure of the AC generator that generates the AC voltage or the fuel. Even if the voltage decreases with the decrease, if the voltage is higher than a voltage that does not hinder the operation of the exchange device connected to the output side, power is supplied without outputting the voltage charged in the storage battery circuit. Therefore, the consumption of the storage battery power supply can be reduced, and the frequency with which the maintenance person charges the storage battery power supply can be reduced.

According to a fifth aspect of the present invention, it is determined whether or not the AC voltage input via the input means is output as it is, whether or not the inverter circuit is activated, and whether or not the AC voltage is charged in the storage battery circuit. Since the display circuit for indicating whether or not is output is provided, the path of the AC voltage can be easily recognized.

According to the sixth aspect, the state of charge of the storage battery circuit can be easily recognized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an uninterruptible power supply according to the present invention.

FIG. 2 is a diagram for explaining an operation of the uninterruptible power supply device shown in FIG. 1; FIG. 2A illustrates an operation when an AC voltage input via an input unit exceeds 95V; FIG. 3B is a diagram for illustrating the case where the AC voltage input through the input unit is 9;
FIG. 3C is a diagram for explaining an operation in the case where the voltage exceeds 2 V and is equal to or less than 95 V. FIG.
It is a figure for explaining operation at the time of 2V or less.

3 is a block diagram showing an example in which an AC generator is connected to the input side of the uninterruptible power supply shown in FIG. 1 and a switching device is connected to the output side.

FIG. 4 is a block diagram showing another embodiment of the uninterruptible power supply according to the present invention.

5A is a diagram for explaining the operation of the display circuit shown in FIG. 4, and FIG. 5A is a diagram for explaining the operation when the AC voltage input via the input unit exceeds 95V; Figure,
(B) is a diagram for explaining the operation when the AC voltage input via the input unit exceeds 92 V and is 95 V or less;
(C) is a diagram for explaining the operation when the AC voltage input via the input unit is 92 V or less.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 AC generator 200 uninterruptible power supply 210 input unit 220 rectifier circuit 230 storage battery circuit 240 charging circuit 250 inverter circuit 260 output unit 270 switching circuit 271, 272 AC switch 273 switching switch 280 control circuit 281 95 V voltage setting circuit 282 92 V voltage setting Circuit 283, 284 Voltage comparison circuit 290 Display circuit 300 Replacement device 400 Power supply line 500a, 500b Fixed length power supply cable

Claims (4)

(57) [Claims] An input means for inputting an AC voltage, a rectifier circuit for converting an AC voltage input via the input means into a DC voltage and outputting the DC voltage, and charging the DC voltage output from the rectifier circuit A storage battery circuit, a DC voltage output from the rectifier circuit or an inverter circuit that converts a DC voltage charged in the storage battery circuit into a stable AC voltage and outputs the AC voltage, and an input through the input means. A switching circuit that outputs one of an AC voltage and an AC voltage output from the inverter circuit based on a predetermined condition;
A power supply switching method for an uninterruptible power supply, comprising: a control circuit that controls an operation of the switching circuit based on the predetermined condition; and an output unit that outputs an AC voltage output from the switching circuit to the outside. When the AC voltage input via the input means is higher than a predetermined first reference voltage, the AC voltage input via the input means is output as it is, via the input means. When the input AC voltage is equal to or lower than the first reference voltage and higher than a second reference voltage having a value lower than the first reference voltage, the AC voltage input via the input unit is changed to The inverter circuit outputs the voltage charged in the storage battery circuit when the AC voltage input through the input means is equal to or lower than the second reference voltage. Feed switching method of the uninterruptible power supply characterized by and output. 2. An input unit to which an AC voltage is input, a rectifier circuit that converts an AC voltage input through the input unit into a DC voltage and outputs the DC voltage, and charges the DC voltage output from the rectifier circuit. A storage battery circuit, a DC voltage output from the rectifier circuit or an inverter circuit that converts a DC voltage charged in the storage battery circuit into a stable AC voltage and outputs the AC voltage, and an input through the input means. A switching circuit that outputs one of an AC voltage and an AC voltage output from the inverter circuit based on a predetermined condition;
An uninterruptible power supply comprising: a control circuit that controls an operation of the switching circuit based on the predetermined condition; and an output unit that outputs an AC voltage output from the switching circuit to the outside. Compares a predetermined first reference voltage with an AC voltage inputted through the input means , and compares the AC voltage inputted through the input means with the first reference voltage.
If the input AC voltage is higher than the first reference voltage,
In this case, the AC voltage input through the input means remains unchanged.
Controlling the switching circuit so as to be supplied to the output means.
The AC voltage input through the input means is
When the voltage is equal to or lower than the reference voltage of 1, the inverter circuit is activated.
And the AC power output from the inverter circuit.
Controlling the switching circuit so that pressure is supplied to the output means.
Compares the first voltage comparison circuit for control, and the AC voltage input through the second reference voltage and the input means is lower than said first reference voltage, the entering
The AC voltage input via the input means is the second reference voltage.
An uninterruptible power supply device , comprising: a second voltage comparison circuit that stops the operation of the rectifier circuit when the voltage is equal to or less than the voltage. 3. The uninterruptible power supply according to claim 2 , wherein the AC voltage input via the input means is output as it is, the inverter circuit is activated, and the storage battery. An uninterruptible power supply device comprising a display circuit that indicates whether or not a voltage charged in a circuit is being output. 4. The uninterruptible power supply according to claim 3 , wherein the display circuit indicates a state of charge of the storage battery circuit.