JP3368594B2 - Auxiliary energy supply circuit for 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 auxiliary energy power supply circuit for an uninterruptible power supply which constantly supplies electric power from an AC power supply to a load and supplies power from a battery to the load when the AC power supply fails.

[0002]

2. Description of the Related Art Generally, an uninterruptible power supply (UPS) is shown in FIG.
It is configured like. In FIG. 4, 1 is a circuit breaker M
A forward converter, for example, a rectifier, that converts AC power input via the CCB into DC power. The output side of the rectifier 1 is connected to an inverse conversion unit that converts DC power into AC power, for example, an inverter 2. A battery 3 and a capacitor 4 are connected to a common connection point between the rectifier 1 and the inverter 2. A transformer 5 transforms the AC output of the inverter 2 and supplies it to a load (not shown). 6 is a capacitor.

In the apparatus constructed as described above, when the AC power supply is normal, the DC output of the rectifier 1 is supplied to the battery 3 for charging, and the inverter 2 converts the AC output to AC power and supplies it to the load. When the AC power source fails, the inverter 2 converts the DC power of the battery 3 into AC power and supplies the AC power to the load. As such a stable and good-quality AC power supply, power is supplied to important loads such as computers.

[0004]

In the device shown in FIG. 4, the energy supply for the power loss during the power conversion operation of the rectifier 1 and the inverter 2 and the internal discharge of the battery 3 is entirely performed from the AC power source side of the uninterruptible power supply device. Is going.
However, since the uninterruptible power supply is originally intended to create a high-quality power supply that does not have a power failure, it is desirable that the loss be as small as possible.

Conventionally, the above-mentioned rectifier 1, inverter 2,
In order to compensate the power loss of the battery 3, the measures shown in Table 1 below are taken.

[0006]

[Table 1]

The present invention has been made in view of the above points, and an object thereof is an uninterruptible power supply capable of effectively supplying energy to an internal discharge of a battery and power loss of the uninterruptible power supply with a simple device. It is to provide an auxiliary energy supply circuit for the device.

[0008]

SUMMARY OF THE INVENTION The present invention is a forward conversion unit for converting the power of an AC power supply into DC power, and a DC output side of the forward conversion unit for converting DC power into AC power and loading the load. And a battery connected to the DC input side of the inverse conversion unit, and when the AC power supply is normal, the AC power of the AC power supply is loaded through the forward conversion unit and the inverse conversion unit. In the uninterruptible power supply device which supplies the load to the load by converting the DC power of the battery into the AC power by the inverse conversion unit when the AC power supply fails, (1) a DC energy supply source arranged in parallel with the battery; A step-up chopper inserted in an electric path connecting a common connection point of the inverse converter and the battery and the DC energy supply source, and the step-up stepper when the battery voltage is low.
Operate the chopper so that the DC energy source
The output side of the boost chopper when fully charged.
Increase the voltage to increase the DC power of the DC energy source.
In addition to supplying to the inverse conversion unit , (2) characterized in that the direct current energy supply source is configured by a solar power generation device, (3) the direct current energy supply source is configured by a fuel cell It is characterized by having done.

[0009]

[0010]

According to the invention of claim 1, after the battery is discharged,
When the voltage is low, operate the boost chopper to
Charge the battery from an energy source. See you
If the battery is fully charged, increase the voltage of the boost chopper.
Raise the DC power of the DC energy supply source to the reverse conversion unit side
Supply. For this reason, the battery power shortage and uninterruptible power supply
The power loss of the device can be easily supplemented,
The surplus power can be sent to the load side.

[0011]

According to the second aspect of the present invention, the energy of solar power generation is natural renewable energy and can be utilized infinitely as long as sunlight is present. Therefore, the battery can be charged even when the AC power source is out of power, and the battery can be charged faster. Further, when solar power generation is generally used, an inverter for converting DC power into AC power is required. However, the present invention can use the inverse conversion unit of the uninterruptible power supply, so an inverter can be added. do not have to.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1, the same parts as those in FIG. 4 are designated by the same reference numerals. 1 is different from FIG. 4 in that a solar power generation device 11 using a solar cell is connected to a common connection point of a rectifier 1, an inverter 2 and a battery 3 via a diode 12 and a step-up chopper 13, and other points. The part is constructed in the same way as in FIG.

In the device constructed as described above, when the voltage is low, such as after the battery 3 is discharged, the boost chopper 13 is operated to charge the battery 3 from the solar power generation device 11. When the battery 3 is sufficiently charged, the booster chopper 13 raises the voltage at the point B in the figure to supply the inverter 2 with the DC power of the photovoltaic power generator 11. As a result, the power shortage of the battery 3, the rectifier 1,
The power loss of the inverter 2 can be easily supplemented and surplus power can be sent to the load side.

Next , a reference example related to the present invention will be described with reference to FIG. 2 is different from FIG. 1 in that the solar power generation device 11 is connected to the positive electrode of the battery 3 via the diode 12, and the common connection point of the diode 12 and the battery 3 is connected via the buck-boost chopper 23 to the rectifier 1 and It is connected to the common connection point of the inverter 2, and the other parts are configured the same as in FIG.

In the device configured as described above, the DC power of the photovoltaic power generator 11 is automatically charged into the battery 3 via the diode 12. When the charging voltage of the battery 3 rises, the buck-boost chopper 23 is operated to send surplus power to the inverter 2. In addition, the solar power generation device 11
Also, the DC power of the battery 3 is supplied to the DC side of the inverter 2 by the operation of the step-up / down chopper 23, and the supply stop is controlled. Therefore, it is possible to easily supplement the shortage of power of the battery 3 and the power loss of the rectifier 1 and the inverter 2, and to send the surplus power to the load side.

The step-up chopper 13 and the step-up / step-down chopper 2
3 is configured as shown in FIG. 3, for example. In FIG. 3, a reactor 31 and a switching transistor 32 are connected in series between the positive and negative terminals of the photovoltaic power generator 11. A diode 34 is connected between the collector and the emitter of the switching transistor 32. A common connection point between the reactor 31 and the switching transistor 32 is a diode 35 and a switching transistor 36.
Is connected to a positive electrode bus bar P (a DC circuit of the uninterruptible power supply) via. A series circuit composed of the diode 35 and the switching transistor 36 (shown by a broken line in the figure) is a circuit for a step-down chopper, and a series circuit composed of a capacitor 38 and a resistor 39 and a diode 40 having the illustrated polarity are connected in parallel at both ends of this circuit. It is connected.

In the chopper circuit configured as described above, the step-up operation is performed by turning on / off the switching transistor 32, and the step-down operation is performed by turning on / off the switching transistor 36. If only the boost chopper is used, the circuit shown by the broken line is omitted.

As another reference example related to the present invention,
Alternatively , the solar power generation device 11 may be directly connected to the DC side of the inverter 2 without the step-up chopper 13 and the step-up / step-down chopper 23. Further, the DC energy supply source of the present invention is not limited to the solar power generation device 11, but a fuel cell or the like can be used to obtain the same effect as the above.

[0020]

As described above, according to the present invention, an AC power supply
Conversion unit for converting the electric power of the above into DC power, and the conversion unit
It is connected to the DC output side of and converts DC power to AC power.
And a DC input of the inverse converter
When the AC power supply is normal, it has a battery connected to
Is a conversion unit for converting the AC power of the AC power supply into a forward conversion unit and an inverse conversion unit.
Supply to the load via AC power source
Uninterruptible power supply that converts alternating current into alternating current in the reverse converter and supplies it to the load
In a power supply device, a DC energy source installed in parallel with the battery
Common connection between the power source and the reverse converter and battery
It is inserted in the electric line connecting the connection point and the DC energy supply source.
When the battery voltage is low,
The DC energy by operating the boost chopper.
Charge the battery from the power supply source, and when the battery is fully charged,
Of the DC energy supply source
Since the DC power is supplied to the inverse converter , the following excellent effects can be obtained.

(1) In the conventional CVCF, the power loss due to the internal discharge of the battery was supplied from the AC power source side. However, according to the present invention, it is possible to replenish from natural renewable energy such as a solar power generation device without relying on an AC power source.
Further, a part of the electric power corresponding to the amount of the battery discharged at the time of AC power failure can be supplied from the solar power generation device or the like.

[0022] (2) Battery fully charged can be powered as part of the output power by <br/> operation of the boost chopper in the inverse transform unit of the uninterruptible power supply (inverter), a rectifier, an inverter, etc. More energy can be supplied than power loss.

(3) The energy of the photovoltaic power generator is natural renewable energy, and as long as sunlight is emitted, it can be used as much as desired and is environmentally friendly.

(4) When the solar power generation device is generally used, an inverter for converting direct current into alternating current is required. However, according to the present invention, since the inverter of the uninterruptible power supply is used, it is not necessary to additionally install an inverter for the photovoltaic power generation device, and it can be automatically used as a power generation inverter.

(5) When the AC power supply is interrupted, the power is once supplied from the battery, then the emergency generator starts to start, and the uninterruptible power supply device starts to send electric power in response to the power supply from the battery. At this time, the charge of the battery discharge may be canceled during this period due to the capacity of the generator, but according to the present invention, the energy from the photovoltaic power generator or the fuel cell is generating power even when the power company is out of power, This energy can be used for battery charging. Therefore, charging of the battery can be accelerated.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a reference example related to the present invention.

FIG. 3 is a circuit diagram showing an embodiment of a main part of the present invention.

FIG. 4 is a circuit diagram showing an example of a conventional uninterruptible power supply device.

[Explanation of symbols]

1 ... Rectifier 2 ... Inverter 3 ... Battery 11 ... Photovoltaic generator 12, 34, 35, 40 ... Diode 13 ... Step-up chopper 23 ... Buck-boost chopper 31 ... Reactor 32, 36 ... Switching transistor

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H02J 9/06 504 H02J 9/06 503 H01L 31/04 H02J 7/35

Claims (3)

(57) [Claims] 1. A forward conversion unit that converts the power of an AC power supply into DC power, and an inverse conversion unit that is connected to the DC output side of the forward conversion unit and that converts DC power into AC power and supplies the load.
A battery connected to the DC input side of the inverse conversion unit, and when the AC power supply is normal, supplies the AC power of the AC power supply to the load via the forward conversion unit and the inverse conversion unit, and the power failure of the AC power supply. At the time, in the uninterruptible power supply device for converting the DC power of the battery into the AC by the inverse conversion unit and supplying it to the load, the DC energy supply source arranged in parallel with the battery, the common connection point of the inverse conversion unit and the battery, and the and a step-up chopper interposed path connecting the DC energy source, when the battery voltage is low operating said boosting chopper
To charge the battery from the DC energy source
However, when fully charged, raise the output side voltage of the boost chopper.
DC power of the DC energy supply source to the inverse conversion unit
An auxiliary energy power supply circuit for an uninterruptible power supply that is characterized by supplying power. 2. The auxiliary energy power supply circuit for an uninterruptible power supply according to claim 1, wherein the DC energy supply source is a photovoltaic power generator. 3. The auxiliary energy power supply circuit for an uninterruptible power supply according to claim 1, wherein the DC energy supply source comprises a fuel cell.