JP2002315229A - Uninterruptible power source equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide uninterruptible power source equipment which reduces a loss occurring in a converter and an inverter of a defect of a conventional normal inverter power supply system, which reduces the capacity of a necessary secondary cell and which decreases a commercial power source usage amount. SOLUTION: The uninterruptible power source equipment supplies power to load equipment 8 via an inverter 6 according to an output from a control circuit 3 connected to an AC commercial power source 1 and an external DC power source 4, inputs a part of the output to a secondary cell 9 via a charger 7, and inputs the output of the cell 9 to the inverter 6. The control circuit 3 controls to supply the power to the equipment 8 from the output singly from the power source 4 at the time of receiving the power from the power source 1 or from the outputs from both the power source 4 and the power source 1 and to simultaneously charge the cell 9 via the charger 7, and controls to supply the output singly from the power source at the time of interrupting the power source 1 or the outputs from both the power source 4 and the cell 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a solar cell panel,
The present invention relates to an uninterruptible power supply device that uses an external DC power supply such as a fuel cell as an auxiliary power supply, operates in conjunction with a commercial power supply, and supplies power to connected load devices.

[0002]

2. Description of the Related Art In a conventional uninterruptible power supply of a constant inverter power supply type, power is always supplied to a load device connected via a converter circuit and an inverter circuit when commercial power is received. Also, at the time of a power failure of the commercial power supply, power is supplied to a load device connected to the uninterruptible power supply connected using the built-in secondary battery as a power supply instead of the commercial power supply.

Therefore, in the event of a commercial power failure, the backup time of the uninterruptible power supply is determined by the capacity of the secondary battery because power is supplied to the connected load device using the built-in secondary battery as a power source instead of the commercial power supply. Determined by
Therefore, the capacity of the secondary battery is determined according to the load and the necessary backup time, and there is a problem that a large-capacity secondary battery is naturally required when the load is large or the backup time is long.

[0004] In addition, when power is received from the commercial power supply, the power input from the commercial power supply is supplied to the load equipment while constantly passing through the converter and the inverter, so that lost power is generated inside the uninterruptible power supply. There was a problem.

[0005]

SUMMARY OF THE INVENTION The present invention reduces the loss that occurs in the converter and the inverter, which are the drawbacks of the conventional continuous inverter power supply type uninterruptible power supply, and reduces the required secondary battery. It is an object of the present invention to provide an uninterruptible power supply with reduced capacity and reduced commercial power consumption.

[0006]

According to a first aspect of the present invention, an AC power supply from an AC commercial power supply is input to a control circuit via a converter, and an external DC power supply is provided. Is supplied to a control circuit via a first DC / DC converter, an output from this control circuit is supplied to a load device via an inverter, and a part of an output from the control circuit is supplied to the control circuit. It is input to the secondary battery via the charger, and the output of this secondary battery is
Input to the control circuit via the DC converter, the control circuit supplies power to the load equipment from the output of the external DC power supply alone or from both the DC power supply and the AC commercial power supply at the time of receiving the AC commercial power supply, and at the same time, supplies the power to the load equipment via the charger. An uninterruptible power supply that controls charging of the secondary battery and controls the external DC power supply alone or the output of both the external DC power supply and the secondary battery to be supplied to the load equipment when the AC commercial power supply fails. is there.

According to a second aspect of the present invention, in the uninterruptible power supply having the configuration of the first aspect, when the commercial power is received, the sum of the power supplied to the load device and the charger is W2. When the maximum output power of the first DC / DC converter is W1, if W1 ≧ W2, the output voltage of the converter is V1, and the first DC / D converter is V1.
V2> V1 when the output voltage of the C converter is V2, and V2 = V1 when W1 <W2.

According to a third aspect of the present invention, there is provided an uninterruptible power supply having the configuration according to the first or second aspect,
When the sum of the power supplied to the load device and the charger at the time of the commercial power outage is W2 and the maximum output power of the first DC / DC converter is W1, the first output is obtained when W1 ≧ W2. The output voltage of the DC / DC converter is V2, and the output voltage of the second DC / DC converter is V2.
3, V2> V3, and W1 <W2, V2
This indicates that control is performed at 2 = V3.

[0009]

FIG. 1 shows the configuration of an uninterruptible power supply according to an embodiment of the present invention.

As shown in FIG. 1, AC power from a commercial power supply 1 is converted into DC power of a voltage V1 by a converter 2,
Input to the control circuit 3. The control circuit 3 receives a DC output from an external DC power supply 4 in addition to the commercial power supply 1,
The voltage is converted to V2 via the C / DC converter 5 and input.

Here, the external DC power supply 4 is a fuel cell,
It is composed of a DC power supply independent of the commercial power supply 1 such as a solar power generator or a wind power generator.

The output from control circuit 3 is input to inverter 6 and charger 7. The DC power input to the inverter 6 is converted into AC power and supplied to the load device 8. A secondary battery 9 is connected to the charger 7 to charge the secondary battery 9, and the output of the secondary battery 9 is the second DC
The DC voltage is converted into a DC voltage V3 via the / DC converter 10 and input to the control circuit 3. By operating the relay 11, the electric power DC-converted by the converter 2 can be supplied to the load device 8 via the bypass circuit 12.

Next, the operation of the uninterruptible power supply shown in FIG. 1 will be described.

When receiving the commercial power, the sum of the power supplied to the load device 8 and the charger 7 is represented by W2, and the output power from the first DC / DC converter 5 is represented by W2.
1, when W1 ≧ W2 (or W1> W2), that is, when the output of the external DC power supply 4
If the power supplied to the
Of the DC / DC converter 5 is controlled to be higher than the output voltage V1 of the converter 2 (V2> V1).

In such a case, since W2 is all supplied from the external DC power supply 4, the commercial power supply need not be used. When W1 <W2 (or W1 ≦ W2) due to a decrease in output power of the external DC power supply 4 or an increase in supply power to the load device 8, the first DC / D
The output voltage V2 of the C converter 5 is controlled so as to be equal to the output voltage V1 of the converter 2, and the converter 2 supplies insufficient power W3, that is, W2-W1.
As described above, since the electric power supplied from the external DC power supply 4 is utilized to the maximum, the power consumption of the commercial power supply can be reduced, and the cost for operation can be reduced. Further, since converter 2 does not always operate, power loss can be suppressed as compared with a conventional uninterruptible power supply in which a converter always operates. When the power load for charging the secondary battery 9 is extremely lower than the load device 8, there is substantially no problem even if only the power supplied to the load device 8 is set to W2.

When W1 ≧ W2 (or W1> W2) at the time of a commercial power failure, the output voltage V2 of the first DC / DC converter 5 is changed to the second DC / DC
Higher than the output voltage V3 of the DC converter 10 (V2>
V3) Control. By performing such control, power is supplied from the external DC power supply 4 to the load device 8 without discharging the secondary battery. If W1 <W2, the first DC /
The output voltage V2 of the DC converter 5 is controlled to be the same as the output voltage V3 of the second DC / DC converter 10, and the insufficient power W3, that is, W2-W1, is supplied from the secondary battery 9 to the second DC / DC converter. It is supplied via a DC converter 10. At this time, the charger 7 may stop charging.

As described above, in order to make maximum use of the power supplied from the external DC power supply 4, the backup time can be extended as compared with the conventional method in which the power is supplied only from the built-in secondary battery. Further, in the case of the same backup time as in the conventional case, a secondary battery having a smaller capacity can be used, and the price of the entire apparatus can be reduced.

[0018]

As described above, according to the uninterruptible power supply according to the present invention, when the commercial power is received, the consumption of the commercial power is reduced and the power loss in the converter is reduced. Can be. Furthermore, in the event of a commercial power failure, the amount of discharge of the secondary battery is reduced, so that a longer backup time can be secured and a secondary battery with a smaller capacity than the conventional one can be selected. This is also industrially very useful because it can also obtain the effect of reducing the price of

[Brief description of the drawings]

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Commercial power supply 2 Converter 3 Control circuit 4 External DC power supply 5 First DC / DC converter 6 Inverter 7 Charger 8 Load equipment 9 Secondary battery 10 Second DC / DC converter

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 5G015 FA08 GA07 HA16 JA11 JA24 JA52

Claims (3)

[Claims] 1. An AC power supply from an AC commercial power supply is input to a control circuit via a converter, and a DC power supply from an external DC power supply is input to the control circuit via a first DC / DC converter. Supply power to a load device via an inverter, a part of the output from the control circuit is input to a secondary battery via a charger, and the output of the secondary battery is supplied to a second DC / DC converter, and the control circuit supplies power to a load device from the output of the external DC power supply alone or from both the external DC power supply and the AC commercial power supply when the AC commercial power is received. At the same time, the secondary battery is controlled to be charged via the charger, and when the AC commercial power supply fails, the external DC power supply alone or the external DC power supply and the secondary An uninterruptible power supply device that controls output of both batteries to the load device. 2. When the commercial power is received, the sum of the power supplied to the load device and the charger is W2, and the maximum output power of the first DC / DC converter is W1, W1 ≧ W2. In this case, when the output voltage of the converter is V1, the output voltage of the first DC / DC converter is V2, V2> V1. When W1 <W2, V2 = V1. The uninterruptible power supply according to claim 1. 3. The power supply to the load device and the charger at the time of the commercial power failure is represented by W2, and the maximum output power of the first DC / DC converter is represented by W1. In this case, when the output voltage of the first DC / DC converter is V2 and the output voltage of the second DC / DC converter is V3, V2> V3, and W
3. The uninterruptible power supply according to claim 1, wherein V1 = V3 when 1 <W2.