JP3188239B2 - AC uninterruptible power supply - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an AC uninterruptible power supply that continuously supplies AC power to devices regardless of a power failure of a commercial AC power supply.

[0002]

2. Description of the Related Art The configuration of a conventional AC uninterruptible power supply is shown in FIG.
It is shown in FIG. An AC uninterruptible power supply 2 is connected to the commercial AC power supply 1, and an AC load 10 is connected to the AC uninterruptible power supply 2.

[0003] The AC uninterruptible power supply 2 comprises a commercial AC power supply 1.
Rectifier 3 for converting the voltage of the rectifier 3 into a DC voltage, a storage battery 4 and an inverter 5 connected to the output terminal of the rectifier 3, an AC switch 6 connected to the output terminal of the inverter 5, A bypass circuit is provided for supplying a voltage to the AC switch by bypassing the rectifier and the inverter.

The storage battery 4 is used as a backup for a power failure of the commercial AC power supply 1 and is charged by the output voltage (DC voltage) of the rectification unit 3. The inverter unit 5 converts the output voltage of the rectifying unit 3 or the voltage of the storage battery 4 into an AC voltage having a predetermined frequency by switching. The AC switch 6 selects one of the output voltage of the inverter unit 5 and the voltage of the bypass circuit 7 and outputs the selected voltage to the outside. This external output is supplied to the AC load 10.

The operation will be described. The rectifier 3 converts the voltage of the commercial AC power supply 1 into a DC voltage. The storage battery 4 is float-charged by the DC voltage, and the DC voltage is supplied to the inverter unit 5. The DC voltage supplied to the inverter unit 5 is converted into an AC voltage having a predetermined frequency, so-called high-reliability and high-quality AC power, and output to the outside through the AC switch 6.

[0006] Commercial AC power supply 1 is out of power (including momentary outage)
In this case, the output voltage of the rectifier 3 becomes zero. When the output voltage of the rectification unit 3 becomes zero, the storage battery 4 is discharged, and the discharge voltage (DC voltage) is supplied to the inverter unit 5 without interruption. The discharge voltage supplied to the inverter unit 5 is converted into an AC voltage having a predetermined frequency, so-called high-reliability and high-quality AC power, and output to the outside through the AC switch 6.
With this external output, the operation of the AC load 10 can be continued regardless of the power failure of the commercial AC power supply 1.

When a failure occurs in the rectifying unit 3 or the inverter unit 5, the AC switch 6 is switched, and the commercial AC power supply 1
Is output to the outside through the bypass circuit 7 without any interruption.

[0008]

When the rectifying unit 3 and the inverter unit 5 fail or maintain, the voltage of the commercial AC power supply 1 is externally output as it is through the bypass circuit 7 and the AC switch 6. When a power failure (including an instantaneous power failure) occurs in the power supply 1, power cannot be supplied to the AC load 10, and the AC load 10 is shut down.

The present invention has been made in view of the above circumstances,
Its purpose is to provide a reliable and high-quality AC power supply to the load without relying on direct power supply from the commercial AC power supply to the load in the event of failure or maintenance of the rectifier or inverter. It is to provide an AC uninterruptible power supply which can be used.

[0010]

According to a first aspect of the present invention, there is provided an AC uninterruptible power supply, comprising: a rectifier for converting a voltage of a commercial AC power supply into a DC voltage; and a storage battery connected to an output terminal of the rectifier. An inverter connected to the output terminal of the rectifier and the storage battery to convert the output voltage of the rectifier or the voltage of the storage battery to an AC voltage, and bypassing the voltage of the commercial AC power supply to the rectifier and the inverter. A first bypass circuit for passing the voltage of the commercial AC power supply to the rectifying unit and the inverter unit, and a second bypass circuit for passing the voltage of the commercial AC power supply to the rectifying unit and the inverter unit. A first selection switch for selecting one of the voltages of the bypass circuit; and selecting one of the output of the first selection switch and the output of the inverter unit to output to the outside. And a second terminal connected to the second bypass switch, and a second terminal connected to the second terminal. Bidirectional power converter having a function of an inverter operation of converting a voltage into an AC voltage and outputting from a second terminal, and a function of a rectifying operation of converting an input voltage to the second terminal into a DC voltage and outputting from a first terminal A switching unit provided upstream of a connection position of the second terminal of the bidirectional power conversion unit in the second bypass circuit; a commercial AC power supply; a rectifying unit;
Depending on the state of the inverter, the bidirectional power converter,
Switching the first selection switch, turning off the second selection switch
In other words, the operation of the bidirectional power converter,
A control unit for controlling opening and closing, wherein the control unit
Power supply, rectifier, inverter, bidirectional power converter
Normally, set the first selection switch on the side of the second bypass circuit.
And set the second selection switch to the inverter side,
Set the close switch to the open state, and
First control means for operating the force conversion unit as an inverter;
In the state where the control of the first control means is performed, the commercial AC power
When an abnormality occurs in the power source, the second selection switch is set to the inverter section.
Control means set on the side, and control of the first control means
Fault occurs in the inverter section in the state where
Switch the second selection switch to the first selection switch
Third control means and a state in which the control of the third control means is performed.
If the bidirectional power conversion unit becomes abnormal in the
Control means for switching the selection switch to the first bypass circuit side
Step and in a state where the control of the third control means is performed.
If an abnormality occurs in the rectifier, the first selector switch is set to the first
Fifth control means for switching to the pass circuit side, and the first control means
Anomalies occur in the rectification unit when the stage is controlled
Rectifying the bidirectional power converter by closing the open / close switch
And switch the first selection switch to the first bypass circuit side
And control of the sixth control means.
If an error occurs in the bidirectional power converter in the
7th control to switch 2 selection switch to 1st selection switch
Control means and a state in which the control by the sixth control means is performed.
When an abnormality occurs in the inverter section, the second selection switch
And an eighth control means for switching the switch to the first selection switch side.
You.

[0011]

[0012]

[0013]

[0014]

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In the drawing, FIG.
The same parts as those described above are denoted by the same reference numerals, and detailed description thereof will be omitted. As shown in FIG. 1, an AC switch 21 as a first selection switch is connected to the commercial AC power supply 1 via a first bypass circuit 11 and a second bypass circuit 12, respectively. First bypass circuit 11 and second bypass circuit 12
Is for bypassing the voltage of the commercial AC power supply 1 to the rectifying unit 3 and the inverter unit 5 in a bypass manner.

The AC switch 21 is connected to the first bypass circuit 1
1 and the voltage of the second bypass circuit 12 are selected and output. Furthermore, this AC switch 2
1 and the output of the inverter unit 5 are supplied to an AC switch 22 as a second selection switch. The AC switch 22 is connected to the output of the AC switch 21 and the inverter unit 5.
One of these outputs is selected and output externally. This output is supplied to the AC load 10.

As shown in FIG. 2, the AC switches 21 and 22 are semiconductor switches 3 such as thyristors and IGBTs.
1, 32, 33, and 34 are used to form two current paths, each of which can be selectively turned on and off by a trigger of each semiconductor switch.

Reference numeral 20 denotes a bidirectional power conversion unit having a first terminal and a second terminal, and an inverter operation for converting an input voltage to the first terminal into an AC voltage having a predetermined frequency by switching and outputting the AC voltage from the second terminal. And a rectifying function of converting an input voltage to the second terminal into a DC voltage and outputting the DC voltage from the first terminal. The first terminal is connected to the output terminal of the rectifier 3 and the storage battery 4, and the second terminal is connected to the second bypass circuit 12.
Connected to.

Then, in the second bypass circuit 12,
An open / close switch 23 is provided upstream of the connection position of the second terminal of the bidirectional power converter 20. On the other hand, a control unit 8 monitors the states of the commercial AC power supply 1, the rectifying unit 3, the inverter unit 5, and the bidirectional power conversion unit 20, and according to the monitoring result, operates the AC switch 21 (first selection switch). Switching,
The switch controls the switching of the AC switch 22 (second selection switch), the operation of the bidirectional power converter 20, and the opening and closing of the open / close switch 23, and includes first to eighth control means .

(1) When the commercial AC power supply 1, rectifier 3, inverter 5, and bidirectional power converter 20 are normal, the AC switch 22 is set to the inverter 5 side (first control).
Control of means) . As a result, the output of the inverter unit 5 via the rectifying unit 3 is output from the commercial AC power supply 1 to the outside.

FIG. 3 shows the operation state of each section. FIG.
, The flow of electric power is indicated by broken lines. That is,
The rectifier 3 converts the voltage of the commercial AC power supply 1 into a DC voltage. The storage battery 4 is float-charged by the DC voltage, and the DC voltage is supplied to the inverter unit 5.
The DC voltage supplied to the inverter unit 5 is converted into an AC voltage having a predetermined frequency, so-called high-reliability and high-quality AC power, and output to the outside through the AC switch 22.

The bidirectional power converter 20 includes an inverter 5
The inverter operates in preparation for a failure or the like, and is in a hot standby state. Accordingly, the AC switch 21 is switched to the second bypass circuit 12 side. The open / close switch 23 is in a closed state.

(2) When an abnormality such as a power failure (including an instantaneous power failure) occurs in the commercial AC power supply 1, the AC switch 22 is set to the inverter unit 5 side (control by the second control means) . Thereby, the output of the inverter unit 5 based on the discharge of the storage battery 4 is output to the outside.

FIG. 4 shows the operation state and power flow of each unit. That is, when the commercial AC power supply 1 experiences a power failure (including an instantaneous power failure), the output voltage of the rectifier 3 becomes zero. Rectification unit 3
When the output voltage of the battery becomes zero, the storage battery 4 is discharged, and the discharged voltage (DC voltage) is supplied to the inverter unit 5 without instantaneous interruption. The discharge voltage supplied to the inverter unit 5 is converted into an AC voltage having a predetermined frequency, so-called high-reliability and high-quality AC power, and output to the outside through the AC switch 22.

With this external output, the operation of the AC load 10 can be continued regardless of the power failure of the commercial AC power supply 1. Bidirectional power converter 20 maintains the hot standby state.

(3) If an abnormality occurs in the inverter unit 5 (including failure of the inverter unit 5 and maintenance of the inverter unit 5), the bidirectional power conversion unit 20 operates as an inverter (in the standby state and the inverter is already in operation). Operating) and the AC switch 22 is instantaneously switched to the AC switch 21 side (control by the third control means) .

Thus, the rectifying unit 2 is switched from the commercial AC power supply 1 to the rectifying unit 2.
AC power is output through the inverter operation of the bidirectional power converter 20. FIG. 5 shows the operation state and power flow of each unit.

(4) In the state where the inverter unit 5 is abnormal and the AC power is output from the commercial AC power supply 1 through the inverter operation of the rectifier 2 and the bidirectional power converter 20 as described above, Further, when an abnormality occurs in the bidirectional power converter 20 (including failure of the bidirectional power converter 20, maintenance of the bidirectional power converter 20), the AC switch 21 is switched to the first bypass circuit 11 side ( No.
4 Control means) .

That is, the voltage of the commercial AC power supply 1 is externally output as it is via the first bypass circuit 11, the AC switch 21, and the AC switch 22. FIG. 6 shows the operation state and power flow of each unit.

(5) In the state where the inverter unit 5 is abnormal and the AC power is output from the commercial AC power supply 1 through the inverter operation of the rectifier 2 and the bidirectional power converter 20 as described above, Further, when an abnormality occurs in the rectification unit 3 (including failure of the rectification unit 3 and maintenance of the rectification unit 3), the AC switch 21 is switched to the first bypass circuit 11 side (control of the fifth control unit) .

That is, the voltage of the commercial AC power supply 1 is externally output as it is via the first bypass circuit 11, the AC switch 21, and the AC switch 22. FIG. 7 shows the operation state and power flow of each unit.

(6) Commercial AC power supply 1, inverter section 5,
If the rectification unit 3 becomes abnormal when the bidirectional power conversion unit 20 is normal, the open / close switch 23 is closed, the bidirectional power conversion unit 20 performs rectification operation, and the AC switch 22
Is set on the inverter section 5 side.

Thus, the AC power is output from the commercial AC power supply 1 through the rectifying operation of the bidirectional power converter 20 and the inverter unit 5, and the storage battery 4 is output through the rectifying operation of the bidirectional power converter 20. Is charged.

FIG. 8 shows the operation state and power flow of each part. The AC switch 21 has been switched to the first bypass circuit 11 side (control by the sixth control means) . (7) The rectifying unit 3 is abnormal, and as described above, the rectifying operation of the bidirectional power conversion unit 20 and the AC power output via the inverter unit 5 are performed from the commercial AC power supply 1, and the bidirectional power conversion unit 20 When the storage battery 4 is charged through the rectification operation of the above, and the AC switch 21 is switched to the first bypass circuit 11 side, and further abnormality occurs in the bidirectional power converter, the AC switch 22 is switched to the AC switch 21 side. Instantaneously (control by the seventh control means) .

That is, the voltage of the commercial AC power supply 1 is externally output as it is via the first bypass circuit 11, the AC switch 21, and the AC switch 22. FIG. 9 shows the operation state and power flow of each unit.

(8) The rectifying unit 3 is abnormal, and as described above,
The rectifying operation of the bidirectional power converter 20 and the output of the AC power through the inverter unit 5 are performed from the commercial AC power supply 1, and the storage battery 4 is charged through the rectifying operation of the bidirectional power converter 20. Switch 21 is connected to first bypass circuit 1
If the inverter unit 5 further malfunctions in the state of switching to the first side, the AC switch 22
Side (the control by the eighth control means) .

That is, the voltage of the commercial AC power supply 1 is externally output as it is via the first bypass circuit 11, the AC switch 21, and the AC switch 22. FIG. 10 shows the operation state and power flow of each unit.

(9) As described above, the bidirectional power conversion unit 20 having the function of the inverter operation and the function of the rectification operation is provided. By performing the alternative operation at the time of (maintenance), it is possible to greatly reduce the opportunity for direct power supply from the commercial AC power supply 1 to the AC load 10. As a result, the system down of the AC load 10 due to the power failure of the commercial AC power supply 1 can be minimized.

In short, from the commercial AC power supply 1 to the AC load 1
The AC power supply to the AC load 10 with high reliability and high quality can be continued without relying on the direct power supply to the AC load 0.

In the above embodiment, the operation of the bidirectional power converter 20, the switching of the AC switch 21, the
Although the case where the switching of 2 and the opening / closing of the open / close switch 23 are automatically operated based on the state monitoring of the control unit 8 has been described, the configuration may be such that maintenance personnel manually operate each. Others
The present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention.

[0046]

As described above, according to the present invention, the bidirectional power converter having the function of the inverter operation and the function of the rectifying operation is provided. When the rectification unit or inverter unit fails or is maintained,
It is possible to provide an AC uninterruptible power supply capable of continuing to supply highly reliable and high-quality AC power to a load without relying on direct power supply from a commercial AC power supply to the load as much as possible.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment.

FIG. 2 is a diagram showing a configuration of an AC switch according to the embodiment.

FIG. 3 is a diagram showing an operation state and a power flow of each unit in the embodiment when each unit is normal.

FIG. 4 is a diagram showing an operation state of each unit and a flow of electric power when a commercial AC power supply is abnormal in the embodiment.

FIG. 5 is a diagram showing an operation state of each unit and a flow of electric power when the inverter unit is abnormal in the embodiment.

FIG. 6 is a diagram showing an operation state and a power flow of each unit when the inverter unit and the bidirectional power conversion unit in the embodiment are abnormal.

FIG. 7 is a diagram showing an operation state of each unit and a flow of electric power when the rectifying unit and the inverter unit are abnormal in the embodiment.

FIG. 8 is a diagram showing an operation state of each unit and a flow of electric power when the rectifying unit is abnormal in the embodiment.

FIG. 9 is a diagram showing an operation state and a power flow of each unit when the rectifying unit and the bidirectional power conversion unit are abnormal in the embodiment.

FIG. 10 is a diagram showing an operation state and power flow of each unit when the rectifying unit and the inverter unit are abnormal in the embodiment.

FIG. 11 is a block diagram showing a configuration of a conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Commercial AC power supply 2 ... AC uninterruptible power supply device 3 ... Rectifier unit 4 ... Storage battery 5 ... Inverter unit 8 ... Control unit 10 ... AC load 11 ... First bypass circuit 12 ... Second bypass circuit 20 ... Bidirectional power conversion unit 21 AC switch (first selection switch) 22 AC switch (second selection switch) 23 Open / close switch

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yuji Kawagoe 3-4-1 Shibaura, Minato-ku, Tokyo Inside NTT Facilities Co., Ltd. (56) References JP-A-9-285135 (JP, A (58) Fields investigated (Int. Cl. ⁷ , DB name) H02J 9/00-11/00

Claims (1)

(57) [Claims] A rectifier for converting a voltage of a commercial AC power supply into a DC voltage; a storage battery connected to an output terminal of the rectifier; an output of the rectifier connected to an output terminal of the rectifier and the storage battery; An inverter unit for converting a voltage or a voltage of a storage battery into an AC voltage; a first bypass circuit for bypassing the voltage of the commercial AC power supply to the rectifying unit and the inverter unit; and a voltage of the commercial AC power supply. A second bypass circuit for bypassing the rectification unit and the inverter unit, and a first selection switch for selecting one of a voltage of the first bypass circuit and a voltage of the second bypass circuit. A second output for selecting one of the output of the first selection switch and the output of the inverter unit and outputting the selected output to the outside;
A selection switch, a first terminal connected to the output terminal of the rectifier and the storage battery;
A second terminal connected to the second bypass circuit and having a terminal, and a function of an inverter operation of converting an input voltage to the first terminal into an AC voltage and outputting the AC voltage from the second terminal;
And converting the input voltage to the second terminal into a DC voltage to
A bidirectional power conversion unit having the function of rectification of output from the terminal, and a closing switch provided on the upstream side of the connecting position of the second terminal of the bidirectional power conversion unit in the second bypass circuit, said commercial AC power supply, the rectifier, the inverter, front
The first selection switch according to the state of the bidirectional power converter.
Switch, the second selection switch, the bidirectional
Controls the operation of the power converter and the opening and closing of the open / close switch
A control unit, wherein the control unit is a commercial AC power supply, a rectifying unit, an inverter unit,
If the bidirectional power converter is normal, set the first selection switch to the second
2 Set to the bypass circuit side and set the second selection switch
Data switch, and set the open / close switch to the open position.
And then make the bidirectional power converter operate as an inverter
A first control means, and a commercial exchange in a state where the control of the first control means is performed.
If the power supply fails, set the second selection switch
A second control means set on the control unit side, and an inverter in a state where the control of the first control means is performed.
When an abnormality occurs in the data section, the second selection switch is first selected.
A third control means for switching to the switch side, and a bi-directional switch in a state where the control of the third control means is performed.
If an abnormality occurs in the power converter, the first selection switch is set to the first
A fourth control unit for switching to a bypass circuit side, and a rectifying unit in a state where the control of the third control unit is performed.
When the abnormality occurs, the first selection switch is turned to the first bypass
A fifth control unit for switching to a road side, and a rectifying unit in a state where the control by the first control unit is performed.
If an abnormality occurs, the on / off switch is closed and the bidirectional power
Rectifying operation of the switching unit and setting the first selection switch to the first bypass.
A sixth control means for switching to a circuit circuit side, and a bi-directional control circuit in a state where the control of the sixth control means is performed.
When an abnormality occurs in the power converter, the second selection switch is set to the first
A seventh control means for switching to the selection switch side, and an inverter in a state where the control by the sixth control means is performed.
When an abnormality occurs in the data section, the second selection switch is first selected.
AC uninterruptible power supply comprising: an eighth control means for switching the switch side.