JP2003189504A - Uninterruptible power supply unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple and reliable uninterruptible power supply unit for a load apparatus, capable of operating even if DC power is supplied in stead of AC power, such as a personal computer body. <P>SOLUTION: This uninterruptible power supply unit 1 supplies AC power from an AC power supply 2 to the AC/DC load apparatus 4 through wiring 8 and an input changing-over switch 10 and converts AC into DC by a rectifier 11 to charge a battery 12 during normal operation. In the event of power failure in the AC power supply 2, the contact of the input changing-over switch 10 is switched from the wiring 8 to wiring 9. Power stored in the battery 2 is supplied to the AC/DC load apparatus 4 as is DC power. The AC/DC load apparatus 4 is operated by the DC power. In addition, the use of a capacitor for the battery 12 provides an extremely simple and inexpensive circuit configuration. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an uninterruptible power supply (UPS: uninterruptible) provided between an AC power supply and a load device in preparation for a power failure of an AC power supply such as a commercial power supply.
power supply). More specifically, the present invention relates to an uninterruptible power supply device for a load device that can operate even when DC power is supplied instead of AC power.

[0002]

2. Description of the Related Art Generally, an uninterruptible power supply supplies AC power from an AC power supply to a load device and charges a storage battery during normal operation, that is, when the AC power supply is not interrupted. By supplying it to the load equipment, the load equipment is prevented from stopping due to a power failure.

FIG. 2 shows the configuration of a conventional uninterruptible power supply device of this type. In a normal state, the uninterruptible power supply 21 outputs the AC power from the AC power supply 22 to the load device 25 via the wiring 23 and the input changeover switch 24.
The C / DC converter 26 converts into direct current, and the direct current power charges the storage battery 27.

When the AC power supply 22 experiences a power failure or an abnormal voltage drop, the uninterruptible power supply 21 detects this by the control circuit 28, and the contact of the input changeover switch 24 from the AC power supply side to the DC / AC side. Switch to the converter 29 side. As a result, the electric power stored in the storage battery 27 is converted into AC power by the DC / AC converter 29 and supplied to the load device 25.

[0005]

As described above, the conventional uninterruptible power supply 21 converts the power stored in the storage battery 27 into AC power by the DC / AC converter 29 when the AC power supply 22 fails. It is configured to be converted and then supplied to the load device 25.

However, the load device 25 does not always need AC power. For example, as in the case of a personal computer (hereinafter referred to as a personal computer) main body, AC power is rectified by an AC / DC converter composed of diodes and the like without using a transformer, and DC power is exclusively used internally. For load devices that
For an extremely short time (about several seconds), it is possible to operate by inputting DC power instead of AC power.

Therefore, when considering an uninterruptible power supply device for a load device that can operate even when DC power is supplied instead of AC power, such as a personal computer body, when an instantaneous power failure such as an instantaneous power failure occurs. When backing up, the DC / AC converter 29 and the AC / DC converter inside the personal computer are unnecessary. In addition, on the contrary, the increase in the number of these components leads to a decrease in the reliability of backup of the uninterruptible power supply.

The present invention was devised under such circumstances, and is simple and reliable for a load device such as a personal computer body which can operate even when DC power is supplied instead of AC power. It is an object to provide an uninterruptible power supply with high cost.

[0009]

In order to solve the above-mentioned problems, the uninterruptible power supply device of the present invention is capable of operating AC power from an AC power supply under normal conditions, normally with AC power as well as with DC power. In the uninterruptible power supply that supplies the load device with the power stored in the storage battery and stores the power in the storage battery, and supplies the power stored in the storage battery to the load device when the AC power fails, the power stored in the storage battery is directly loaded as DC power. It is configured to supply to equipment.

With such a configuration, the DC / AC converter provided in the latter stage of the storage battery in the conventional uninterruptible power supply can be omitted. That is, with this configuration,
As an uninterruptible power supply for load equipment that can operate even with DC power, a simple and highly reliable uninterruptible power supply can be realized.

In addition, an AC / D for converting the load equipment into the direct current from the alternating current power from the alternating current power source without passing through the transformer.
It is preferably operated by the DC power converted by the C converter.

If the load device is configured in this way, backup by DC power can be reliably performed for a predetermined time.

Further, it is preferable that the storage battery comprises a capacitor, and that the capacitor is discharged to supply DC power to the load device.

By using a capacitor for the storage battery, it is possible to easily realize an uninterruptible power supply device having an extremely simple and inexpensive circuit structure with high reliability.

Further, it is preferable to provide a rectifier for rectifying the current from the AC power source and a boost chopper circuit for boosting the DC power from the rectifier and storing it in a capacitor.

By rectifying the current from the AC power source by the rectifier and boosting the obtained DC power by the boosting chopper circuit to store it in the capacitor, the storage efficiency can be improved and a certain discharge time can be secured. That is, when the DC power from the rectifier is stored in the capacitor as it is, the output voltage of the rectifier also decreases when the voltage (peak value) of the AC power supply decreases, so the power stored in the capacitor decreases and the discharge time shortens. However, by boosting the DC power from the rectifier and storing it in the capacitor, it is possible to always secure a certain amount of power stored in the capacitor and eliminate variations in discharge time and discharge power due to voltage fluctuations in the AC power supply.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION A preferred embodiment of the present invention will be described below with reference to FIG.

Uninterruptible power supply 1 shown in this embodiment
Is connected to an input terminal 3 connected to an AC power supply 2 and a load device 4 (such as an AC / DC load device in this embodiment) that can operate with AC power or DC power, such as a personal computer body. It also has a first output terminal 5 and a second output terminal 7 connected to a load device (hereinafter referred to as an AC load device in this embodiment) 6 that operates only with AC power.

AC capable of operating with AC power or DC power
As the / DC load device 4, a structure is adopted in which the power from the AC power source is directly rectified by a diode or the like without passing through a transformer, and the DC power obtained thereafter is set to a predetermined value. In the case of a structure in which the power from the AC power supply is stepped down via a transformer, it cannot be driven with DC power, so either do not connect it to the first output terminal 5 or output the AC / DC load device 4. By detecting the current, it is determined whether or not it can be driven by DC power.

Inside the uninterruptible power supply 1, an input terminal 3 is provided.
An AC power line 8 for guiding the AC power from the AC power supply to the first and second output terminals 5 and 7 and a DC power line 9 provided in parallel with the line 8 are provided. The output terminal of the wiring 8 for AC power on the first output terminal 5 side and the output terminal of the wiring 9 for DC power are selectively connected to the first output terminal 5 via the input changeover switch 10. It has become. On the other hand, the second output terminal 7 is always the wiring 8 for AC power.
It is connected to the.

A rectifier 11 for rectifying the current from the AC power source 2 and a storage battery 12 for storing the power from the rectifier 11 are connected to the wiring 9 for the DC power. A diode is used for the rectifier 11, and a capacitor is used for the storage battery 12.

Between the rectifier 11 and the storage battery 12, a boost chopper circuit 13 for boosting the DC power from the rectifier 11 and storing it in the storage battery 12 is provided. The step-up chopper circuit 13 uses a solenoid (inductance L) 14 provided in the middle of the wiring 9 and the induced electromotive force of the solenoid 14 to boost the direct-current power from the rectifier 11 to supply it to the storage battery 12. And a switch circuit 15 that performs switching. This switch circuit 15
The operation of the input changeover switch 10 is controlled by the control circuit 16.

The control circuit 16 constantly monitors the voltage of the input terminal 3, and when the voltage of the input terminal 3 is a normal voltage, the contact of the input changeover switch 10 is connected to the wiring 8 for AC power.
Control to hold on the side. Further, the boost chopper circuit 13 is operated so that the output voltage of the storage battery 12 becomes a predetermined value or more. When the control circuit 16 detects an abnormal voltage drop, the control circuit 16 controls to switch the contact of the input changeover switch 10 to the DC power wiring 9 side. A known one-chip microcomputer or the like is used for the control circuit 16.

Uninterruptible power supply unit 1 configured as described above
Under normal conditions, the AC power from the AC power supply 2 is supplied to the AC /
The DC power is supplied to the DC load device 4, converted into DC by the rectifier 11, and the storage battery 12 is charged with this DC power. At this time, AC power is also supplied to the AC load device 6.

The uninterruptible power supply 1 detects, by the control circuit 16, when a power failure or abnormal voltage drop of the AC power supply 2 occurs, and the input changeover switch 1
The 0 contact is switched from the side of the wiring 8 for AC power to the side of the wiring 9 for DC power. As a result, the electric power stored in the storage battery 12 is supplied to the AC / DC load device 4 as DC power.

Therefore, the AC / DC load device 4 can be operated even when the AC power supply 2 fails. on the other hand,
The AC load device 6 is stopped because the power supply is cut off.
However, the AC load device 6 is generally a DRAM (Dynamic
Random access memory) is often not provided with volatile memory, and even if it is provided with non-volatile memory, it can be used again as long as power is resumed even if data is lost due to a power outage. Often For this reason, in many cases there is no problem even if the power supply is momentarily stopped.

For example, when the AC / DC load device 4 is a personal computer main body and the AC load device 6 is a peripheral device such as a display, the personal computer main body uses a volatile memory as a main memory to operate, so even for a moment. When the power supply is stopped, the data in use is lost and the operation cannot be continued. However, there is no problem with the peripheral devices such as the display if the power supply is momentary.

As described above, the uninterruptible power supply 1 of this embodiment does not have the DC / AC converter 29 provided in the latter stage of the storage battery in the conventional uninterruptible power supply, and therefore the AC power supply 2 is There is a drawback that the power supply to the AC load device 6 is not backed up at the time of power failure. However, this uninterruptible power supply 1 has a sufficient function as an uninterruptible power supply for the AC / DC load device 4, and the conventional DC / AC
It can be said that the merit that it can be realized with a simple circuit configuration without the converter is more than the above-mentioned drawback.

Further, since the storage battery 12 uses a capacitor, the uninterruptible power supply 1 can be realized with an extremely simple and inexpensive circuit configuration. Further, since the storage battery 12 using the capacitor cannot store electric power enough to overheat a heavy load component such as a transformer, a direct current power from the storage battery 12 may cause a step-down transformer or the like in the AC / DC load device 4. It does not cause problems such as burning.

Further, the controller circuit 16 turns on and off the switch circuit 15 to operate the step-up chopper circuit 13 to step up the DC power from the rectifier 11 and store it in the storage battery 12 made of a capacitor. Even if the voltage of the terminal 3 fluctuates, it is possible to always secure a certain amount of electric power stored in the capacitor, to prolong the discharge time, and to eliminate variations in the discharge time and the electric power.

Since the uninterruptible power supply system 1 of this embodiment does not have the conventional DC / AC converter 29, the number of parts can be reduced by about 30%. Also, due to this reduction in the number of parts, the accident rate can be expected to decrease by about 40%.

Further, the uninterruptible power supply 1 can sufficiently cope with a momentary power failure (a momentary power failure), but
It cannot handle long-term blackouts such as hours. However, by providing a large number of rectifiers 11 and storage batteries 12 in parallel, using a large-capacity capacitor, and devising the configuration of the AC / DC load device 4 side, it becomes possible to cope with a long power failure. .

The above-described embodiment is an example of a preferred embodiment of the present invention, but various modifications can be made without departing from the scope of the present invention. For example, as an example of the AC / DC load device 4 that can be normally driven by AC power as well as DC power, a communication device for a PC such as a router or a modem can be used in addition to the PC body. If the router or the modem does not have an internal battery such as a dry battery, if the power supply from the outside is momentarily cut off during communication, the communication will be cut off. However, the uninterruptible power supply 1 according to the present embodiment. By using, the DC power is supplied immediately when a power failure occurs, so that the disconnection of communication can be prevented.

In addition, the uninterruptible power supply 1 of the above-mentioned embodiment is configured to output the DC power from the storage battery 12 without transforming it. However, the storage battery 12 and the input changeover switch 1
It is also possible to provide a DC / DC converter between 0 and 0 to transform the voltage into a predetermined voltage and then output the voltage.

Although the second output terminal 7 for the AC load device 6 is provided in the above embodiment, the second output terminal 7 may not be provided. Conversely, two or more second output terminals 7 may be provided. Further, the wiring 9 for DC power may be branched from the middle to provide a plurality of first output terminals 5, or a circuit including a rectifier 11, a storage battery 12, and a step-up chopper circuit 13 may be further provided in parallel.
A plurality of first output terminals 5 may be provided.

The boost chopper circuit 13 may not be provided. Furthermore, the control of the boost chopper circuit 13 may be based on the voltage detected at the input terminal 3 and the detected value. For example, when the voltage of the input terminal 3 falls within a normal value range but drops below a predetermined value, the switch circuit 15 can be turned on / off to increase the voltage.

[0037]

As described above, according to the present invention,
The following effects can be obtained. That is, when the AC power supply fails, the power stored in the storage battery is supplied to the load device as DC power, so a simple load device that can operate even if DC power is supplied instead of AC power. It is possible to realize a highly reliable uninterruptible power supply.

[Brief description of drawings]

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

FIG. 2 is a circuit diagram showing a configuration of a conventional uninterruptible power supply device.

[Explanation of symbols]

1: Uninterruptible power supply 2: AC power supply 3: Input terminal 4: Load device (AC / DC load device) 5: First output terminal 6: Load device (AC load device) 7: Second output terminal 8: Wiring 9: Wiring 10: Input selector switch 11: Rectifier 12: Storage battery 13: Boost chopper circuit 16: Control circuit

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takatoshi Komaoka             1-11-15 East Gotanda, Shinagawa-ku, Tokyo             Wave Building Densei Lambda Stock Association             In-house F-term (reference) 5G015 GA04 GA06 GB02 JA05 JA32                       JA52 JA60

Claims (4)

[Claims] 1. The AC power from the AC power supply during normal operation
Normally, it operates with AC power as well as supplies it to load equipment that can also operate with DC power, and stores power in a storage battery.
In the uninterruptible power supply for supplying the electric power stored in the storage battery to the load device at the time of power failure of the AC power supply, the electric power stored in the storage battery is supplied to the load device as DC power. An uninterruptible power supply characterized by that. 2. An AC that converts the AC power from the AC power supply into DC into the load device without passing through a transformer.
The uninterruptible power supply according to claim 1, wherein the uninterruptible power supply operates according to the DC power converted by the DC / DC converter. 3. The storage battery comprises a capacitor, and the DC power is supplied to the load device by discharging the capacitor.
Uninterruptible power supply described. 4. A rectifier for rectifying the current from the AC power supply, and a boost chopper circuit for boosting the power from the rectifier and storing the boosted power in the capacitor. Blackout power supply.