JP2013230063A - Power supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply capable of supplying power with a small fluctuation to a load, with smooth activation of an internal combustion engine using an electric power storage in the event of a blackout.SOLUTION: A power supply 1 includes: a power storage device 4 for storing power; an electric generator 5 for supplying power to a load 10 by the internal combustion engine when a commercial power supply is lost; a first switch SW1 for switching between a commercial power supply 2 and the electric generator 5; a first power converter 7 for converting the AC power of the commercial power supply 2 or the electric generator 5 into DC power; a bidirectional DC/DC converter 8 for converting a DC voltage; a second power converter 9 for converting DC into AC; a second power converter 9 for converting the DC power from the first power converter 7 or the bidirectional DC/DC converter 8 into AC power; and a second switch SW2 for switching between the second power converter 9 and the commercial power supply 2.

Description

  The present invention relates to a power supply device that supplies electric power from an internal combustion engine during a power failure.

  There is a power supply device that drives an internal combustion engine and continues power supply to a load when power supply from a commercial power supply is stopped due to a power failure or the like. A predetermined time is required from when the power failure occurs until stable electric power is supplied by the internal combustion engine, and this time delay becomes a problem in important load facilities. Therefore, an uninterruptible power supply that supplies electric power from a power storage to a load is already in use until the internal combustion engine moves to a stable operation. There is a demand for shortening the transition time from the occurrence of a power failure to an internal combustion engine.

  As an example of such a power supply device, in the power supply device shown in Patent Document 1, when an activation inverter is installed between the power generation device and the power storage and the power generation device is activated, the activation inverter is interposed. Thus, power from the power storage is supplied to the power generator. Therefore, the start-up time of the power generation device can be shortened because the power generation device operates as an electric motor based on the electric power from the power storage. Further, since the power from the power generation device and the power storage device are combined and supplied to the load when the power from the power generation device is unstable, stable power can be supplied to the load.

  Moreover, in the emergency power supply apparatus shown by patent document 2, while supplying electric power from a commercial power supply to load at the time of normal operation, a battery is charged. Immediately after the power failure, power from the battery is converted into AC power by an inverter, AC power is supplied to the load, and the cell motor is rotated to operate a high-frequency (400 Hz) generator. When the output voltage from the generator stabilizes after a lapse of a certain time, the AC power from the generator is supplied to the rectifier circuit to obtain DC power, and the DC power is converted into AC power by an inverter, and then passed through the UPS switch. To supply the load. As a result, the cost of the emergency power supply device can be reduced and the number of discharges from the battery can be reduced, so that the life of the battery can be extended.

JP 2006-304400 A JP 2001-103679 A

  However, in the power supply device of Patent Document 1, a system for integrating (sharing) a power storage device is disclosed, but a capacitor and three types (startup, charge / discharge, and output) are bidirectional. Since an inverter is used, the system becomes complicated and the current flows in both directions, resulting in poor efficiency. Further, there is a problem that even if the load amount increases, the engine / generator cannot perform a high efficiency operation while maintaining a constant load operation.

  Moreover, in the emergency power supply apparatus of patent document 2, although an example of the emergency power supply apparatus which supplies electric power for starting of an emergency generator directly from the battery incorporated in the uninterruptible power supply apparatus is disclosed. The uninterruptible power supply device is provided with a diode for preventing backflow, and the battery cannot be charged / discharged when the load fluctuates in the steady operation region of the emergency generator. However, there is a problem that high-efficiency operation cannot be performed while maintaining constant load operation.

  The present invention has been made in order to solve the above-described problems, and can smoothly start an internal combustion engine by a power storage during a power failure, and can supply power with less fluctuation to a load. The object is to provide a possible power supply.

  In order to solve the above problems, a power supply apparatus according to the present invention is driven by an electric power storage unit that stores electric power and an internal combustion engine that is started by the electric power stored in the electric power storage unit when commercial power is lost, and supplies electric power to the load. A generator to be supplied; a first switch that switches between the commercial power source and the generator; a first power converter that converts AC power of the commercial power source or the generator into DC power; and the first A bidirectional DC / DC converter provided between the power converter and the power storage, for converting a direct current voltage; connected to the first power converter and the bidirectional DC / DC converter; A second power converter that converts the DC power of the power converter or the power storage into AC power, and a second switch that switches between the second power converter and a commercial power supply. What to do A.

  According to the power supply device of the present invention, the load storage power storage unit and the power storage unit for driving the internal combustion engine starting DC motor are integrated (shared), and the internal combustion engine / generator is in a steady operation. At the time of load feeding, the internal combustion engine / generator can be operated at a constant load, and charging or discharging of the power storage device using the bidirectional DC / DC converter can be controlled to cope with load fluctuations. There is an effect that it is possible to realize high-efficiency operation by lowering the fuel consumption rate.

1 shows an overall configuration diagram of a power supply system to which a power supply device according to Embodiment 1 is applied. FIG. It is a figure which shows the state at the time of commercial power supply use in the power supply device which concerns on Embodiment 1 (at the time of normal). It is a figure which shows the state at the time of the commercial power failure generation | occurrence | production in the power supply device which concerns on Embodiment 1. FIG. It is a figure which shows the state at the time of the generator start in the power supply device which concerns on Embodiment 1. FIG. It is a figure which shows the state at the time of generator steady operation in the power supply device which concerns on Embodiment 1. FIG. It is a figure which shows the state at the time of the commercial power recovery in the power supply device which concerns on Embodiment 1. FIG. It is a figure which shows the time transition of load electric power feeding, electrical storage device electrical storage amount, and generator output in a series of operation | movement of the power supply device which concerns on Embodiment 1. FIG. It is a figure which shows the other embodiment of the state at the time of the generator starting in the power supply device which concerns on Embodiment 1. FIG. It is a figure which shows the state at the time of commercial power supply use (normal time) in the power supply device which concerns on Embodiment 2. FIG. It is a figure which shows the state at the time of the commercial power failure generation | occurrence | production in the power supply device which concerns on Embodiment 2. FIG. It is a figure which shows the time transition of load electric power feeding, the electrical storage device electrical storage amount, and a generator output in a series of operation | movement of the power supply device which concerns on Embodiment 2. FIG.

The power supply device according to the present invention continues power supply to the load by the generator of the internal combustion engine at the time of commercial power failure (when lost), and starts the internal combustion engine by the power storage device and supplies power to the load. It is. Hereinafter, a power supply device according to an embodiment of the present invention will be described with reference to FIGS.

Embodiment 1 FIG.
FIG. 1 is a diagram illustrating an overall configuration of a power supply system to which the power supply device according to the first embodiment is applied, and FIG. 2 illustrates a state of the power supply device according to the first embodiment when the commercial power supply is used (normal time). FIG. 3 is a diagram showing a state when a commercial power failure occurs in the power supply device according to the first embodiment, and FIG. 4 is a state when the generator is started in the power supply device according to the first embodiment. FIG. 5 is a diagram illustrating a state during the steady state operation of the generator in the power supply device according to the first embodiment. FIG. 6 is a diagram illustrating a state when the commercial power supply is restored in the power supply device according to the first embodiment. Further, FIG. 7 is a diagram showing a time transition of load power feeding, power storage device power storage amount, and generator output in a series of operations of the power supply device according to the first embodiment.

  First, the overall configuration of a power supply system to which the power supply device according to the first embodiment is applied will be described with reference to FIG. The power supply device 1 is installed between the commercial power source 2 and the load 10 and includes a power failure detection relay (27R) 3 that monitors the supply state of AC power supplied from the commercial power source 2, and a power storage device 4 that stores power. When the commercial power source is lost, the generator 5 by the internal combustion engine that is started by the power of the power storage device 4 and supplies power to the load 10, the starting DC motor 6 that starts the internal combustion engine, the commercial power source 2, and the generator 5 are switched. Between the first switch SW 1, the first power converter (converter) 7 that converts the AC power of the commercial power source 2 or the generator 5 into DC power, and between the first power converter 7 and the power storage device 4. A bidirectional DC / DC converter 8 provided for converting a DC voltage; a second power converter 9 connected to the bidirectional DC / DC converter 8 for converting DC to AC; and a first power converter 7. Or A second power converter (inverter) 9 for converting DC power from the directional DC / DC converter 8 into AC power; a second power converter 9 for supplying AC power to the load 10; Are configured by a second switch SW2 for switching between and an internal combustion engine start switch SW3.

Next, details of a series of operations of the power supply device according to Embodiment 1 of the present invention will be described with reference to FIGS.
[When using commercial power (normal)]
The operation of the power supply device 1 at the normal time shown in FIG. 2 will be described. Both the first changeover switch SW1 and the second changeover switch SW2 are set on the commercial power source 2 side. Therefore, power is supplied to the load 10 from the commercial power source 2 side. At the same time, after the AC power of the commercial power supply 2 is converted to DC by the first power converter (converter) 7 through the first switching SW1, the voltage is adjusted by the bidirectional DC / DC converter 8, and then the power It is stored in the electricity storage device 4 which is a storage.

[Commercial power failure (when lost)]
The operation of the power supply device 1 when the commercial power source 2 shown in FIG. 3 is no longer supplied with power due to a power failure or the like will be described. When power is not supplied from the commercial power source, first, it is detected that a power failure has occurred by the power failure detection relay (27R) 3 that monitors the supply state of AC power from the commercial power source 2. In this state, the supply of power to the load 10 is cut off. When the power failure is detected by the power failure detection relay (27 </ b> R) 3, the internal combustion engine start switch SW <b> 3 is turned on, DC power is supplied from the power storage device 4 to the starter DC motor 6 of the internal combustion engine, and is connected to the generator 5. Start the engine.

[When starting the generator]
The operation of the power supply device 1 when the generator 5 is started after a power failure of the commercial power supply 2 shown in FIG. 4 will be described. The internal combustion engine is started, power generation by the generator 5 is started, and supply of AC power is started. When the AC power from the generator 5 is stabilized, the first changeover switch SW1 is switched to the generator 5 side. At the same time, the second changeover switch SW2 is also switched to the load 10 side. The power supplied from the generator 5 is once converted from AC power to DC power by the first power converter (converter) 7. This DC power is supplied to the load 10 through the second change-over switch SW2 as AC power matched to the commercial power supply frequency by the second power converter (inverter) 9. At this time, a time delay of several tens of seconds occurs from the start of the power failure until the output power of the generator 5 is stabilized and the power is supplied to the load 10. A part of the power supplied from the generator 5 converted from AC power to DC power by the first power converter (converter) 7 is adjusted in voltage by the bidirectional DC / DC converter 8 and then stored in the storage device. 4 is also stored.

[During steady generator operation]
Next, the operation of the power supply device 1 when the generator 5 shown in FIG. 5 is in steady operation will be described. In steady operation, the internal combustion engine is in a stable state and enters constant load operation. Accordingly, the output power of the generator 5 is also constant. In the internal combustion engine, the fuel consumption rate (unit power, fuel consumption per unit time) increases due to the fluctuation of the load 10. The bidirectional DC / DC converter 8 provided between the power storage device 4 and the load 10 can flatten the load fluctuation by charging / discharging the power storage device 4. As a result, it is possible to operate the internal combustion engine with high efficiency, which can reduce the fuel consumption rate.

[When the commercial power is restored]
The operation of the power supply apparatus 1 when the commercial power supply 2 shown in FIG. 6 is restored and the power supply is resumed will be described. When it is detected by the power failure detection relay (27R) 3 that the supply of power from the commercial power source 2 has been resumed, the second changeover switch SW2 is switched to the commercial power source 2 side and power is supplied to the load 10. . Since the internal combustion engine needs to perform after-cooling operation at low load after load operation, only the electricity storage device 4 stores electricity during the after-cooling operation. When this cooling operation is completed, the first switching SW1 also selects the commercial power supply 2 side, stops the internal combustion engine, and returns to the state of the power supply device 1 in the normal state of FIG.

  FIG. 7 shows time transitions of the load power supply, the power storage device power storage amount, and the generator output in the series of operations of the power supply device 1 of FIGS. These show the operation when the power supply device of the present invention is used as an emergency power supply device. There is a power outage period until power is supplied to the load by the generator, but as an emergency power supply, within 40 seconds from the start of the power outage until the output power of the generator is stabilized and power is supplied to the load If it is good.

  FIG. 4 shows the operation of the power supply device 1 when the load 10 at the time of initial application is small when the generator 5 is started after a power failure of the commercial power supply 2. When the load 10 is large, FIG. As shown in FIG. 8, the power storage device 4 can be discharged instead of charged if the load is large when the load is fed. Usually, the capacity of the internal combustion engine / generator is often influenced by the load at the time of initial charging (a large capacity internal combustion engine / generator is required by the load at the time of initial charging even if the rated load is small). Since the power storage device 4 bears a part of the initial load, the capacity of the internal combustion engine / generator can be reduced, and the power supply device can be reduced in size.

  Thus, according to the power supply device according to the first embodiment, the load storage power storage unit and the power storage unit that drives the starting DC motor of the internal combustion engine are integrated (shared), and the internal combustion engine / At the time of load feeding in steady operation of the generator, the internal combustion engine / generator is operated at a constant load, and the charge or discharge of the storage device is controlled using a bidirectional DC / DC converter to cope with load fluctuations Therefore, it is possible to expect an effect that the fuel consumption rate of the internal combustion engine can be lowered and high-efficiency operation can be realized.

Embodiment 2. FIG.
The power supply device according to the second embodiment is the same as the power supply device according to the first embodiment applied to the power supply system shown in FIG. 1, and FIG. 9 shows the use of the commercial power supply in the power supply device according to the second embodiment. FIG. 10 is a diagram illustrating a state in a normal state, and FIG. 10 is a diagram illustrating a state when a commercial power failure occurs in the power supply device according to the second embodiment. FIG. 11 is a diagram showing time transition of load power feeding, power storage device power storage amount, and generator output in a series of operations of the power supply device according to the second embodiment.

  The difference between the power supply device according to the second embodiment and the power supply device according to the first embodiment is that the power supply device is used as an uninterruptible power supply (UPS). The components of the power supply device according to the second embodiment are the same as those of the first embodiment, and thus description thereof is omitted.

Next, details of a series of operations of the power supply device according to Embodiment 2 of the present invention will be described with reference to FIGS.
[When using commercial power (normal)]
The operation of the power supply device 1 at the normal time shown in FIG. 9 will be described. The first changeover switch SW1 is set on the commercial power supply 2 side, and the second changeover switch SW2 is set on the second power converter (inverter) 9. The power supplied from the commercial power source 2 is once converted from AC power to DC power by the first power converter (converter) 7. This DC power is supplied to the load 10 through the second change-over switch SW2 as AC power matched to the commercial power supply frequency by the second power converter (inverter) 9. At the same time, after the AC power of the commercial power supply 2 is converted to DC by the first power converter (converter) 7 through the first switching SW1, the voltage is adjusted by the bidirectional DC / DC converter 8, and then the power It is stored in the electricity storage device 4 which is a storage. Therefore, the first embodiment is different from the first embodiment in that the first changeover switch SW1 is set on the commercial power source 2 side and power is not directly supplied from the commercial power source 2 to the load 10, but the first power converter. The power is supplied to the load 10 through the (converter) 7 and the second power converter (inverter) 9.

[Commercial power failure (when lost)]
An operation of the power supply device 1 when the commercial power source 2 shown in FIG. 10 is not supplied with power due to a power failure or the like will be described. When power is not supplied from the commercial power source 2, it is first detected that a power failure has occurred by the power failure detection relay (27 </ b> R) 3 that monitors the supply state of AC power from the commercial power source 2. When a power failure is detected by the power failure detection relay (27R) 3, the DC power converted from the voltage from the power storage device 4 via the bidirectional DC / DC converter 8 is adjusted to the commercial power frequency by the second power converter (inverter) 9. Electric power is supplied to the load 10 as AC power. At the same time, the internal combustion engine start switch SW3 is turned on, DC power is supplied from the power storage device 4 to the start DC motor 6 of the internal combustion engine, and the internal combustion engine connected to the generator 5 is started.

  Since the operation of the power supply device 1 at the time of starting the generator 5, during steady operation of the generator 5, and at the time of power recovery of the commercial power supply 2 is the same as that described in the first embodiment, description thereof is omitted (FIG. 4). To FIG. 6).

  FIG. 11 shows time transitions of load power feeding, power storage device power storage amount, and generator output in a series of operations of the power supply device 1 according to the second embodiment. FIG. 11 shows an operation when the power supply device 1 of the present invention is used as an uninterruptible power supply device. After a power failure is detected, power can be supplied from the storage device instantaneously, and the power failure time can be almost eliminated.

  In the second embodiment, a commercial power source is converted into direct current by a converter, and alternating current synchronized with the commercial power source is constantly generated by a constant voltage constant frequency control inverter while charging the power storage device. In principle, switching fluctuations when the commercial power supply is stopped do not occur, so that it can be used for applications in which voltage drop and power waveform disturbance are not allowed.

  As described above, according to the power supply device according to the second embodiment, the power failure time can be eliminated by supplying power from the power storage device simultaneously with the occurrence of the power failure of the commercial power supply, and the same as in the first embodiment. When the load is fed during steady operation of the internal combustion engine / generator, the internal combustion engine / generator is operated at a constant load, and charging or discharging of the power storage device using a bidirectional DC / DC converter is controlled. Since the fluctuation can be dealt with, it is possible to expect an effect that the fuel consumption rate of the internal combustion engine can be lowered and high-efficiency operation can be realized.

  In addition, as an electrical storage device, a secondary battery and an electric double layer capacitor can be used, and the secondary battery includes a lead storage battery, a nickel cadmium battery, a nickel hydrogen battery, a lithium ion battery, a sodium sulfur battery, and the like.

  Also, within the scope of the present invention, the embodiments can be freely combined, or the embodiments can be appropriately modified or omitted.

  Moreover, in the figure, the same code | symbol shows the same or an equivalent part.

DESCRIPTION OF SYMBOLS 1 Power supply device 2 Commercial power supply 3 Power failure detection relay 4 Power storage device 5 Internal combustion engine / generator 6 DC motor for starting 7 First power converter (converter)
8 Bidirectional DC / DC converter 9 Second power converter (inverter)
10 Load SW1 First changeover switch SW2 Second changeover switch SW3 Internal combustion engine start switch

Claims (6)

A power reservoir for storing power;
A generator driven by an internal combustion engine that is started by stored power of the power storage device when commercial power is lost, and supplies power to the load;
A first switch for switching between the commercial power source and the generator;
A first power converter that converts AC power of the commercial power source or the generator into DC power;
A bidirectional DC / DC converter that is provided between the first power converter and the power storage and converts a DC voltage;
A second power converter that is connected to the first power converter and the bidirectional DC / DC converter and converts direct current power of the first power converter or the power storage into alternating current power;
A power supply apparatus comprising: a second switch for switching between a second power converter and a commercial power supply.   The power supply apparatus according to claim 1, wherein the power of the commercial power supply is stored in the power storage unit.   3. The power supply device according to claim 1, wherein when the commercial power is lost, power is supplied from the power storage to the load until output power of the generator is stabilized.   The power supply device according to any one of claims 1 to 3, wherein a part of the electric power of the generator is stored in the power storage unit when the commercial power supply is lost.   4. The power supply device according to claim 1, wherein when the commercial power is lost, the power of the generator and the power storage is supplied together to the load. 5.   The power supply device according to claim 5, wherein the generator is driven at a constant output, and a load variation is supplemented with electric power from the power storage.

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