power supply

Abstract

To provide a power supply device that can obtain a stable output of electric power while utilizing electric power generated using natural energy. [Solution] The power supply device 10 comprises a power generation unit 12, an internal battery 16 that charges with power generated by external power generation means 50, 52, a voltage conversion means 24 that converts the input voltage based on the power generated by the power generation unit 12 and the power charged in the internal battery 16 into single-phase or three-phase AC and outputs it to the outside, and a power generation control means 18 that controls the power generation by the power generation unit 12, and the power generation control means 18 puts the power generation unit 12 into a stopped state when the voltage conversion means 24 is in a state where it can output single-phase or three-phase AC of a predetermined voltage to the outside based on the power of the internal battery 16, and puts the power generation unit 12 into a power generation state when the voltage conversion means 24 is in a state where it cannot output single-phase or three-phase AC of a predetermined voltage to the outside based on the power of the internal battery 16.

Description

[Technical Field]

[0001] The present invention relates to a power supply device configured to be able to output alternating current. [Background technology]

[0002] In recent years, the diversification of power supplies has progressed, and many power generation systems that utilize natural energy, such as photovoltaic power generation using solar panels and wind power generation, have been put into practical use to complement conventional power generation facilities such as thermal power generation, hydroelectric power generation, and nuclear power generation. Furthermore, such power generation systems are not limited to configurations in which they are used in parallel with the power company's transmission system, and have the advantage that they can be introduced in areas where the power company's transmission facilities are insufficient, such as mountainous areas and remote areas, as long as natural energy can be used for power generation.

[0003] While power generation systems that utilize natural energy have advantages, they have inherent problems, such as the amount of power generated being dependent on the natural environment and unstable output power. To solve this problem, for example, Patent Document 1 proposes a technology in which power generated by a power generation system that utilizes natural energy as external power generation means is charged into a battery, and the power output from the battery is converted into single-phase or three-phase alternating current and then output externally. In this way, by charging a battery with power generated using natural energy as well, the output power can be stabilized. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Utility Model Registration No. 3219331 Summary of the Invention [Problem to be solved by the invention]

[0005] However, even when charging batteries with electricity generated using natural energy, if an environment unsuitable for power generation continues, there is a problem that the battery may not be able to store enough electricity or the stored electricity may be depleted, making it impossible to obtain a stable output of electricity. For example, in a power generation system using solar power generation, a drop in output voltage is unavoidable not only at night but also during prolonged cloudy or rainy weather when sufficient sunlight does not penetrate. Similar problems of unstable power output are unavoidable when generating electricity using other natural energy sources.

[0006] In other words, the present invention has been proposed to effectively solve the above-mentioned problems inherent in conventional technology, and aims to provide a power supply device that can obtain a stable output of power while utilizing electricity generated using natural energy. [Means for solving the problem]

[0007] In order to solve the above problems and achieve the intended purpose, the first invention is: A power supply device configured to be able to output AC, an internal power generation means; a battery that charges with power generated by an external power generation means; a voltage conversion means for converting the voltage of the electric power generated by the internal power generation means and the electric power charged in the battery into a single-phase or three-phase AC voltage and outputting the converted AC voltage to an external device; power generation control means for controlling power generation by the internal power generation means; The power generation control means is configured to stop the internal power generation means when the voltage conversion means is in a state where single-phase or three-phase AC of a predetermined voltage can be output to the outside based on the power of the battery, and to put the internal power generation means into a power generation state when the voltage conversion means is in a state where single-phase or three-phase AC of a predetermined voltage cannot be output to the outside based on the power of the battery. In this way, by providing an internal power generating means and a battery that charges with power generated by the external power generating means, the power output can always be provided from either the battery or the internal power generating means as a power source, depending on whether a predetermined power output can be achieved based on the battery's power. In other words, a power supply device not previously available can be configured that combines the functions of an inverter generator that outputs power based on power generated by the internal power generating means with the functionality of a power conditioner that outputs power based on power stored in the battery. Therefore, even when a power generating system that utilizes natural energy, which is easily affected by the natural environment, is used as the external power generating means, a continuous, stable power output can be achieved without interruption, even in environments where the power generation by the external power generating means is unstable. Furthermore, by using the power generated by the power generating system that utilizes natural energy as the external power generating means as the primary power source and the internal power generating means as a secondary power generating means, fuel costs can be reduced. Furthermore, because a power generating system that utilizes natural energy can be used as the external power generating means, the power supply device of the present invention can be suitably used in areas where the power transmission facilities of electric power companies are insufficient, such as mountainous regions and remote areas.

[0008] The second idea is a voltage monitoring means for monitoring the output voltage of the battery; The internal power generating means is configured to switch between a stopped state and a power generating state based on the monitored voltage of the voltage monitoring means. In this way, by monitoring the battery power, it is possible to stabilize the output power.

[0009] The third idea is The gist is that the battery is configured to be able to be charged with the electric power generated by the internal power generation means. In this way, by making it possible to charge the battery with the power generated by the internal power generation means, the surplus power generated by the internal power generation means can be charged into the battery, and by filling the battery with power, it becomes possible to output power at all times.

[0010] The fourth idea is The gist is that the device is provided with an external connection part that is connected to the battery, and is configured so that an external battery can be connected to the external connection part. In this way, by making it possible to connect an external battery, it is possible to increase the storage capacity according to the installation environment of the power supply device according to the present invention.

[0011] The fifth idea is The voltage conversion means DC voltage conversion means for converting an input DC voltage using the battery and the internal power generation means as power sources into a predetermined voltage; The power supply unit further comprises a DC-AC converter that converts the DC voltage converted by the DC voltage converter into a single-phase or three-phase AC voltage and outputs the AC voltage to an external device. In this way, stable power output can be obtained while utilizing power generated using natural energy. [Effects of the Invention]

[0012] According to this invention, stable power output can be obtained while utilizing electricity generated using natural energy. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a block diagram illustrating a power supply device according to the present invention; [Figure 2] 1 is a block diagram showing a power supply device according to the present invention, illustrating a current flow when an external power generating means is used as a power source and a current is output to the outside. [Figure 3] 1 is a block diagram of a power supply device according to the present invention, showing the current flow when the internal power generating means is used as a power source and current is output to the outside. DETAILED DESCRIPTION OF THE INVENTION

[0014] Next, a preferred embodiment of the power supply device according to the present invention will be described with reference to the accompanying drawings. In this embodiment, the components constituting the power supply device are housed inside a housing (not shown) to form a unit, and in the following description will be referred to as power supply unit 10.

[0015] As shown in FIG. 1 , the power supply unit 10 includes a power generation unit (internal power generation means) 12 that generates power within the power supply unit 10, an internal battery 16 that charges with power (current) generated by power generation means (external power generation means 50, 52) provided outside the power supply unit 10, and a voltage conversion means 24 that converts input voltage based on the power generated by the power generation unit 12 and the power charged in the internal battery 16 into single-phase or three-phase AC and outputs the power. The power generation unit 12 may be a generator using an internal combustion engine, such as a gasoline generator, diesel generator, or gas generator, capable of generating power, or any of various conventional generators, such as a steam turbine generator. Furthermore, a DC generator may also be used instead of an AC generator. In this embodiment, a gasoline generator, diesel generator, or gas generator is used as the power generation unit 12, and the AC generated by the power generation unit 12 is converted by the AC-DC conversion means 14 to a DC voltage, which is input to the first voltage conversion means 24. An AC / DC converter is preferably used as the AC-DC conversion means 14.

[0016] The internal battery 16 may be a conventionally known storage battery such as a rechargeable lead-acid battery, alkaline battery, or lithium-ion secondary battery, with lithium-ion secondary batteries being particularly preferred due to their high energy density, excellent charge / discharge efficiency, and wide operating temperature range. The external power generation means 50, 52 may be any conventionally known means capable of generating electric power, with a power generation system utilizing natural energy being particularly preferred. Such a power generation system utilizing natural energy may be a DC power generation device 50 such as a solar power generation device that uses sunlight to output DC, or an AC power generation device 52 such as a wind power generation device or a hydroelectric power generation device.

[0017] The power supply unit 10 is also provided with an expansion terminal (external connection section) 32 to which an external battery 56 can be connected. The external battery 56 connected to the expansion terminal 32 is adapted to be connected to the built-in battery 16 provided in the power supply unit 10, and by connecting the external battery 56, it is possible to expand the overall power storage capacity of the power supply unit 10. In the following description, the built-in battery 16 and the external battery 56 may sometimes be simply referred to as batteries without any distinction being made between them.

[0018] The power supply unit 10 includes a power generation control means 18 that controls power generation by the power generation unit 12. This power generation control means 18 controls the power generation unit 12 to stop power generation when the voltage conversion means 24 can output a predetermined voltage of single-phase or three-phase AC power to an external device based on power supplied from the internal battery 16, and controls the power generation unit 12 to operate and generate power when the voltage conversion means 24 cannot output a predetermined voltage of single-phase or three-phase AC power to an external device based on power supplied from the internal battery 16. Switching the power generation unit 12 between the stopped state and the generating state can be performed based on whether the output voltage of the internal battery 16 meets a set threshold, or can also be performed based on whether the input / output power difference between the amount of power input to and the amount of power output from the internal battery 16 meets a set threshold. The control based on the output voltage of the internal battery 16 will now be described in detail. Since the control based on the input / output power difference can be performed based on the same criteria as the control based on the output voltage, details thereof will be omitted. That is, in the power supply unit 10, the power generation unit 12, AC-DC conversion means 14, and voltage conversion means 24 constitute an inverter generator 11, and the voltage conversion means 24 of the inverter generator 11 is configured to be used as a power conditioner that converts the power of the built-in battery 16 into single-phase or three-phase AC of a predetermined voltage and outputs it.

[0019] Specifically, the power generation control means 18 incorporates a voltage monitoring circuit (voltage monitoring means) 18a that monitors the output voltage of the built-in battery 16, and is configured to monitor the output voltage (monitored voltage) of the built-in battery 16 connected to the power generation control means 18. When the monitored voltage monitored by the voltage monitoring circuit 18a falls below a predetermined threshold, the power generation unit 12 is placed in a power generating state to generate electricity, and when the monitored voltage exceeds the predetermined threshold, the power generation unit 12 is placed in a stopped state to stop power generation. In other words, the power generation unit 12 is switched between a stopped state and a power generating state based on the monitored voltage, and single-phase or three-phase AC can be output to the outside continuously without interruption depending on the charge state of the built-in battery 16.

[0020] Here, the monitoring voltage threshold for switching the power generating unit 12 from the stopped state to the generating state does not need to be the same as the monitoring voltage threshold for switching the power generating unit 12 from the generating state to the stopped state, and may be set to different values. By setting the monitoring voltage threshold for switching the power generating unit 12 to the stopped state to a value higher than the monitoring voltage threshold for switching the power generating unit 12 to the generating state, the frequency with which the operating state of the power generating unit 12 is switched can be reduced.

[0021] To explain the configuration of the power supply unit 10 in more detail, the internal battery 16 is connected to a first DC voltage conversion means 20 that increases or decreases DC voltage to different levels. The power supply unit 10 is configured so that external power generation means 50, 52 can be connected to the first DC voltage conversion means 20 via an input terminal 22 (input connection section) provided on the power supply unit 10. That is, the first DC voltage conversion means 20 converts the DC input from the external power generation means 50, 52 to a voltage suitable for charging, thereby charging the internal battery 16. A so-called DC / DC converter is preferably used as this first DC voltage conversion means 20. Note that when an AC power generation device 52 is used as the external power generation device, the AC generated by the AC power generation device 52 is converted to DC using an AC-DC conversion means 54, and the converted DC is input to the first DC voltage conversion means 20, thereby enabling the AC power generation device 52 to be used as the external power generation device. Here, an AC / DC converter is preferably used as the AC-DC conversion means 54.

[0022] The voltage conversion means 24 includes second DC voltage conversion means 26 connected to be able to receive DC voltage from the power generation unit 12 and the built-in battery 16 as its power source, and is configured to convert the DC voltage input from the power generation unit 12 and the built-in battery 16 as its power source into a predetermined voltage. That is, when an AC generator is used as the power generation unit 12, the DC voltage obtained by converting the AC generated by the power generation unit 12 using the AC-DC conversion means 14 is input to the second DC voltage conversion means 26, and when a DC generator is used, the DC voltage generated by the power generation unit 12 is input to the second DC voltage conversion means 26. Here, a DC / DC converter can be suitably used as the second DC voltage conversion means 26, similar to the first DC voltage conversion means 20.

[0023] DC-AC conversion means 28 is connected to second DC voltage conversion means 26, and is configured to convert the DC from the second voltage conversion means into single-phase or three-phase AC by DC-AC conversion means 28. An inverter can be suitably used as DC-AC conversion means 28. This voltage conversion means 24 is configured to be connected to output terminals 30, and the single-phase or three-phase AC converted by voltage conversion means 24 (DC-AC conversion means 28) is output to external equipment (not shown) connected to the output terminals.

[0024] The voltage conversion means 24 is configured to input the power generated by the power generation unit 12 to the built-in battery 16 to charge the built-in battery 16. In this embodiment, the built-in battery 16 is charged by the power supplied by the power generation unit 12, which has been converted to DC voltage by the AC-DC conversion means 14. That is, when a state occurs in which single-phase or three-phase AC of a predetermined voltage cannot be output to the outside based on the power of the built-in battery 16, the built-in battery 16 is charged while single-phase or three-phase AC of a predetermined voltage is output to the outside based on the power generated by the power generation unit 12, so that a state in which external output is possible based on the power of the built-in battery 16 can be quickly restored.

[0025] The operation of the power supply unit 10 according to the present invention configured as above will now be described. As shown in FIG. 2, DC voltage generated by a DC power generator (external power generating means 50, 52) or DC voltage converted by an external AC / DC converter from AC power generated by an AC power generator (external power generating means 50, 52) is input to the first DC voltage conversion means 20 via the input terminal 22 of the power supply unit 10, and the internal battery 16 is charged at a voltage suitable for charging. If an external battery 56 is connected to the extension terminal 32, charging of the external battery 56 is also performed simultaneously. When the output voltage of the internal battery 16 exceeds a predetermined threshold, the DC voltage is input to the voltage conversion means 24 using the internal battery 16 as a power source. The voltage conversion means 24 then converts the DC voltage to a predetermined voltage using the second DC voltage conversion means 26, which may be a DC / DC converter, and then converts the converted voltage to single-phase or three-phase AC using the DC-AC conversion means 28, which outputs the converted voltage to the outside. At this time, the power generation unit 12 is stopped by the power generation control means 18. The arrows in FIG. 2 indicate the flow of current.

[0026] Furthermore, when the internal battery 16 is insufficiently charged and the voltage of the internal battery 16 monitored by the voltage monitoring circuit of the power generation control means 18 falls below a predetermined threshold, the power generation control means 18 controls the power generation unit 12 to a power generating state, as shown in FIG. 3, and the power generation unit 12 generates power. When the power generation unit 12 generates power, the power generated by the power generation unit 12 is input to the voltage conversion means 24. Then, in the voltage conversion means 24, the power is converted to a predetermined voltage by second DC voltage conversion means 26, which is composed of a DC / DC converter or the like, and the converted single-phase or three-phase AC voltage is output to the outside by the DC-AC conversion means 28. At this time, the internal battery 16 and the external battery 56 are simultaneously charged with the power generated by the power generation unit 12. Note that the arrows in FIG. 3 indicate the flow of current.

[0027] Then, when the internal battery 16 is charged by power generation by the power generation unit 12 and power generation by the external power generation means 50, 52, and the output voltage (monitored voltage) of the internal battery 16 exceeds a predetermined threshold, the power generation control means 18 switches the power generation unit 12 to a stopped state, as shown in Fig. 2, whereby the internal battery 16 is used as a power source and a voltage is input to the voltage conversion means 24, which converts the power from the internal battery 16 to single-phase or three-phase AC and outputs it to the outside, as described above. In this way, when the power supply unit 10 of the present invention is in a state where it is possible to output single-phase or three-phase AC of a predetermined voltage to the outside based on the power of the internal battery 16, it stops power generation by the power generation unit 12 and outputs it to the outside based on the power of the internal battery 16, and when it is not possible to output single-phase or three-phase AC of a predetermined voltage to the outside based on the power of the internal battery 16, it outputs it to the outside based on the power generated by the power generation unit 12.

[0028] In this way, the system is provided with the built-in battery 16 that charges the power input from the external power generating means 50, 52, and the power generating unit 12, and depending on whether or not a predetermined power can be output to the outside based on the voltage of the built-in battery 16, single-phase or three-phase AC of a predetermined voltage can be output to the outside using either the built-in battery 16 or the power generating unit 12 as a power source. Therefore, even in an environment where the power generation of the external power generating means 50, 52 is unstable, a continuous stable output is possible without interruption of power output. Also, by using the power generated by a power generating system that uses natural energy as the main power source for the external power generating means 50, 52 and using the power generating unit 12 as a supplementary power generating means, the consumption of fossil fuels such as gasoline can be reduced, and carbon dioxide (CO2) and nitrogen oxides (NO2) can be reduced. x ), and fuel costs can be kept low. Furthermore, because a power generation system that utilizes natural energy can be employed as the external power generation means 50, 52, the power supply unit 10 of the present invention can be suitably used in mountainous regions, remote areas, and other areas where the power transmission facilities of electric power companies are inadequate.

[0029] Furthermore, switching between operating and stopped states of the power generating unit 12 can be achieved by monitoring the output voltage of the built-in battery 16, making it possible to stabilize the output power with a simple configuration. Here, the threshold value of the output voltage (monitored voltage) that puts the power generating unit 12 into a power generating state and the threshold value of the output voltage (monitored voltage) that puts the power generating unit 12 into a stopped state do not need to be the same value, and by setting the threshold value of the output voltage (monitored voltage) that puts the power generating unit 12 into a stopped state to a higher value, it is possible to reduce the frequency at which the power generating unit 12 switches between operating and stopped states.

[0030] By making it possible to charge the built-in battery 16 with the power generated by the power generation unit 12 and the external power generation means 50, 52, it is possible to charge the built-in battery 16 with surplus power generated by the power generation unit 12, and it is possible to set the built-in battery 16 to a state where it can be output externally as a power source. Furthermore, by making it possible to connect an external battery 56 to the power supply unit 10, it is possible to increase the storage capacity according to the installation environment of the power supply unit 10, thereby improving versatility.

[0031] Although the power supply unit 10 according to the present invention has been described with reference to a preferred embodiment, the configuration of the power supply unit 10 is not limited to that shown in the embodiment, and it goes without saying that various modifications are possible within the scope of the present invention. For example, although the present embodiment shows an example in which the components that make up the power supply device are housed inside a housing and integrated into a unit, the components may be provided individually and connected together. [Explanation of symbols]

[0032] 12 power generation unit (internal power generation means), 16 built-in battery (battery) 18 power generation control means, 18a power supply monitoring circuit (power supply monitoring means) 24 voltage conversion means, 32 expansion terminal (external connection part), 56 external battery 26 Second DC voltage conversion means (DC voltage conversion means) 28 DC-AC conversion means, 50 DC power generation device (external power generation means) 52 AC generator (external power generation means)

Claims

1. A power supply device configured to be able to output AC, an internal power generation means; a battery that charges with power generated by an external power generation means; a voltage conversion means for converting an input voltage based on the power generated by the internal power generation means and the power charged in the battery into a single-phase or three-phase AC voltage and outputting the converted voltage to an external device; power generation control means for controlling power generation by the internal power generation means; The power generation control means is configured to stop the internal power generation means when the voltage conversion means is in a state where it is possible to output single-phase or three-phase AC at a predetermined voltage to the outside based on the power of the battery, and to put the internal power generation means into a power generation state when the voltage conversion means is in a state where it is not possible to output single-phase or three-phase AC at a predetermined voltage to the outside based on the power of the battery. A power supply device characterized by:

2. a voltage monitoring means for monitoring the output voltage of the battery; 2. The power supply device according to claim 1, wherein the internal power generating means is switched between a stopped state and a power generating state based on the monitored voltage of the voltage monitoring means.

3. 3. The power supply device according to claim 1, wherein the battery is charged with the electric power generated by the internal power generating means.

4. 4. The power supply device according to claim 1, further comprising an external connection section that is connected to the battery, and that is configured so that an external battery can be connected to the external connection section.

5. The voltage conversion means DC voltage conversion means for converting an input DC voltage using the battery and the internal power generation means as power sources into a predetermined voltage; 5. The power supply device according to claim 1, further comprising a DC-AC converter for converting the DC voltage converted by said DC voltage converter into a single-phase or three-phase AC voltage and outputting it to an external device.

Images