JP2003009419A - Power supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that a user can not choose the usage and can not extend a time of use in the conventional composition. SOLUTION: In this power source equipment, a control circuit 16 which controls the output voltage of an inverter 14 adjusts the output voltage of the inverter according to the condition set in an output voltage setting means 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device capable of converting DC output power of a solar cell into AC power of commercial frequency and supplying the AC power to household AC equipment.

[0002]

2. Description of the Related Art FIG. 8 is a connection diagram showing a configuration of a conventional power supply device. This power supply is a solar cell 1
And a converter 2 for charging the battery 3 with the DC output of the solar cell 1, and an inverter 4 for converting the DC voltage of the battery 3 into an AC voltage. The inverter 4 is composed of four switching elements each having a diode connected in parallel, a reactor, and a capacitor. The output of the inverter 4 is output through the AC output outlet 5. The control circuit 6 that controls the inverter 4 detects the AC output voltage of the inverter 4, compares the detected voltage with an internal reference wave, and switches so that the detected voltage matches the target voltage. It determines the pulse width of the device.

The operation will be described below. The converter 2 charges the battery 3 with the electric power obtained from the solar cell 1 by performing control to track the maximum output of the solar cell 1 which changes depending on the sunshine. The inverter 4 converts the DC voltage of the battery 3 into an AC voltage of a commercial frequency by operating based on a command from the control circuit 6. That is, the inverter 4 controls the DC voltage of the battery 3 by pulse width control (PW) based on the command from the control circuit 6.
M), a high-frequency pulse voltage train is generated, and the high-frequency ripple is removed by passing the pulse voltage through the reactor and the capacitor to generate a sinusoidal voltage waveform.

The output of the inverter 4 is supplied to an AC output outlet 5, and when an electric device is connected to the AC output outlet 5, the electric device is supplied with 50 Hz or 6 Hz.
An AC voltage of 100 V with a sine wave of 0 Hz is supplied.

[0005]

The above-mentioned conventional structure has a problem in that the user may not be able to select the usage, and the usage time cannot be extended.

That is, regardless of the type of equipment connected, a voltage of 100 V of commercial frequency is always supplied.

[0007]

The present invention comprises a solar cell,
A converter connected in parallel to the output of the solar cell,
A battery connected to the converter, an inverter that converts DC power of the solar cell or the battery into AC power, and a control circuit that controls the output voltage of the inverter are provided as constituent elements, and the control circuit is an output voltage setting unit. The power supply device is configured to adjust the output voltage of the inverter according to the conditions set in.

Since the output voltage of the inverter is adjusted according to the setting of the output voltage setting means, it is possible for the user to select the usage such as saving the power consumption and extending the usage time of the power supply device. And the power supply device.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention described in claim 1 is a solar cell, a converter connected in parallel to the output of the solar cell, a battery connected to the converter, and a direct current of the solar cell or the battery. A configuration in which an inverter that converts electric power into AC power and a control circuit that controls the output voltage of the inverter are provided as constituent elements, and the control circuit adjusts the output voltage of the inverter according to the conditions set by the output voltage setting means. Power supply device.

Since the output voltage of the inverter is adjusted according to the setting of the output voltage setting means, it is possible for the user to select the usage such as saving the power consumption and extending the usage time of the power supply device. And the power supply device.

According to a second aspect of the present invention, in addition to the configuration according to the first aspect, the control circuit adjusts the output voltage of the inverter according to the output of the battery capacity detecting means for detecting the capacity of the battery. Power supply device.

The control circuit sets the output of the inverter to a small value when the capacity of the battery falls below a certain level, so that the power supply device can be used for a long time.

According to a third aspect of the present invention, in addition to the configuration according to the first or second aspect, the control circuit sets the output voltage of the inverter according to the setting condition of the output waveform setting means for setting the output waveform of the inverter. The power supply is configured to control the waveform.

In the sine wave and the rectangular wave, the rectangular wave has less high-frequency loss generated in the inverter. Therefore, when a device other than a device that needs a sine wave is used, a power supply device that can be used for a long time can be obtained by setting a rectangular wave output.

According to a fourth aspect of the present invention, in addition to the configuration according to the second or third aspect, the control circuit changes the waveform of the output voltage of the inverter when the output of the battery capacity detecting means becomes equal to or less than the set capacity. The power supply device is configured to change from a sine wave to a rectangular wave.

In the sine wave and the rectangular wave, the rectangular wave has less high frequency loss generated in the inverter. Therefore, when a device other than a device that needs a sine wave is used, a power supply device that can be used for a long time can be obtained by setting a rectangular wave output.

[0017]

(Embodiment 1) A first embodiment of the present invention will be described below. FIG. 1 is a block diagram showing the configuration of this embodiment. The power supply device according to the present embodiment includes a solar cell 11 and a converter 12 connected in parallel to the output of the solar cell 11.
A battery 13 connected to the converter 12, an inverter 14 for converting the DC power of the solar cell 11 or the battery 13 into AC power, and a control circuit 16 for controlling the output voltage of the inverter 14.

The inverter 14 has a structure in which four switching elements 14a to 14d are connected to a full bridge, and a reactor 14e and an output capacitor 14f are connected to intermediate terminals of the full bridge connection.

The control circuit 16 has an output voltage setting means 17 composed of switches, and drives the four switching elements 14a to 14d in accordance with the conditions set in the output voltage setting means 17. In this way, the output voltage of the inverter 14 is adjusted. The control circuit 16 compares the detected AC output voltage with an internal reference wave, determines the pulse widths of the switching elements 14a to 14d so as to match the target voltage, and supplies a gate signal to each switching element. .

The operation of this embodiment will be described below.
The inverter 14 uses the solar cell 11 as an input power source, supplies the DC power of the solar cell 11 whose power obtained by the sunshine conditions fluctuates to the battery 13 via the converter 12, and charges the battery 13. It is used as a stable DC voltage source. The electric power stored in the battery 13 is converted into an AC voltage having a commercial frequency by the inverter 14 and supplied to the AC output outlet 15. Therefore, when an electric appliance (not shown) is connected to the AC output outlet 5, the electric appliance is driven at a commercial frequency. At this time, in the sunshine condition where the electric power from the solar cell 11 is not obtained, the inverter 14 is used in reverse,
The battery 13 is charged by the inverter 14. That is, a commercial power source (not shown) is connected to the AC output outlet 15 to drive the inverter 14.
In this state, the reactor 14e and the capacitor 14f form a resonance circuit, and the switching elements 14a to 1
By turning on and off 4d, the resonance voltage generated in the resonance circuit is converted into a high frequency pulse voltage, and the battery 13 is charged.

As described above, the inverter 14 supplies the AC voltage of the commercial frequency to the AC output outlet 15 regardless of the sunshine conditions. However, as described above, when the direct current output of the solar cell 11 is reduced due to the sunshine conditions or the like, the inverter 14 must be supplied with commercial power from the input outlet 15 to sufficiently charge the battery 13.
Therefore, it is impossible to supply sufficient electric power to the electric appliances connected to the AC output outlet 15.

In this respect, in this embodiment, as shown in FIG. 1, the control circuit 16 is provided with the output voltage setting means 17. The output voltage setting means 17 is set by the user.

FIG. 2 is an explanatory diagram for explaining the operation of the control circuit 16 when the output voltage setting means 17 is set to ON and when it is set to OFF. As shown in FIG. 2, the control circuit 16 detects the connection state of the output voltage setting means 17 and changes the amplitude of the AC output voltage. That is, the output voltage is changed.

For example, when the output voltage setting means 17 is on, the setting means signal fetched by the control circuit 16 is Lo.
Becomes At this time, the control circuit 16 controls the switching elements 14a to 14d of the inverter 14 as described above to control the output voltage to AC100V. Further, when the output voltage setting means 17 is off, the setting means signal fetched by the control circuit 16 becomes Hi. At this time, the output voltage is controlled to 90V AC. That is, the control circuit 16
Is for changing the gate signal supplied to the inverter 4 according to the setting condition of the output voltage setting means 17.

As described above, according to the present embodiment, the output voltage setting means 17 is provided so that the user can easily change the output voltage. It is also possible for the user to select the usage such as extending. Therefore, it is possible to realize a highly convenient photovoltaic power generation system with a built-in battery.

(Embodiment 2) Next, a second embodiment of the present invention will be described. FIG. 3 is a block diagram showing the configuration of this embodiment. In this embodiment, the battery capacity detecting means 18 for detecting the capacity of the battery 13 is used. In the present embodiment, the battery capacity detecting means 18 measures the terminal voltage of the battery 13, and this information is transmitted to the control circuit 16.

FIG. 4 is an explanatory diagram showing the operation of the control circuit 16. That is, the control circuit 16 compares the detection information of the battery capacity detection means 18 with an internal threshold value,
The target output voltage is determined according to the result of this comparison.
When the detected amount of the battery capacity detecting means 18 is a predetermined amount or more (threshold value or more), a gate signal corresponding to AC100V is output, and when the detected amount is less than the predetermined amount (threshold value or less), the output voltage is AC90V The pulse width (gate signal) is changed so that For example, in the case of lighting, if the supply voltage is low, the illuminance is reduced but the power consumption is reduced, so that it can be used for a long time.

As described above, according to the present embodiment, the battery capacity is detected, and the output voltage is lowered when the battery capacity is reduced, so that the power consumption of the connected equipment can be reduced, and therefore, it can be used. A power supply device that can extend the time can be realized.

(Embodiment 3) Next, a third embodiment of the present invention will be described. FIG. 5 is a block diagram showing the configuration of this embodiment. In this embodiment, the control circuit 16 is provided with output waveform setting means 19.

FIG. 6 is an explanatory diagram for explaining the operation of the control circuit 16 of this embodiment. The control circuit 16 detects the connection state of the output waveform setting means 19 and changes the AC output waveform. That is, when the output waveform setting means 19 is on, the setting means signal taken into the control circuit 16 becomes Lo, and the output voltage waveform is controlled to be a sine wave. When the output waveform setting means 19 is off, the setting means signal taken into the control circuit 16 is Hi, and the output waveform is controlled to be a rectangular wave. That is, the control circuit 16 changes the gate signal supplied to the inverter 4 in accordance with the setting of the system setting means 19.

In the case of the sine wave output, since the direct current is switched at a high frequency, the switching elements 14 (a) ...
In (d), switching loss occurs in addition to conduction loss. However, in the case of rectangular wave output, since the switching elements 14 (a) to (d) are switched at the commercial frequency, almost no switching loss occurs, so that the loss of the inverter 14 can be reduced. Therefore, since the loss can be reduced, the home electric appliance can be used for a long time.

As described above, according to the present embodiment, the output waveform setting means 19 is provided so that the output waveform can be changed by the user's will, and even when the sine wave is required and the rectangular wave is required. It is possible to distinguish between good cases and good cases. In particular, when the capacity of the battery 13 is small, it is possible to use it for a long time by reducing the loss, and it is possible to realize a highly convenient power supply device.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described. FIG. 7 is a waveform diagram showing the operation of this embodiment. In this embodiment, the change of the output waveform described in the third embodiment is operated in conjunction with the detection signal of the battery capacity detection means 18 described in FIG. That is, the control circuit 16 determines the output waveform by comparing the detection amount of the battery capacity detection means 18 with a threshold value inside the control circuit 16.

The operation of the battery built-in type photovoltaic power generation system configured as described above will be described. Control circuit 1
Reference numeral 6 detects a signal generated from the battery capacity detecting means 18, compares it with an internal threshold value, and outputs a sine wave to the inverter 14 when the battery capacity is large. However, when the battery capacity decreases and becomes less than or equal to the threshold value, the gate signal is changed to on / off at the commercial frequency that outputs a rectangular wave. When a sine wave is output, direct current is switched at a high frequency, so that the switching elements 14 (a) to (d) generate switching loss in addition to conduction loss. However, in the case of rectangular wave output, switching loss hardly occurs, so that the loss of the inverter can be reduced. Since the loss can be reduced, it becomes possible to use the home electric appliance for a long time.

As described above, according to the present embodiment, based on the detection signal obtained by the battery capacity detection means 18, when the battery capacity is small, a rectangular waveform in which the switching loss is almost zero from the sine wave output with a large high frequency loss. By changing the output waveform into a wave, a power supply device that can be used for a long time can be realized.

[0036]

According to the invention described in claim 1, the solar cell, the converter connected in parallel to the output of the solar cell, the battery connected to the converter, and the DC power of the solar cell or the battery. An inverter for converting to AC power and a control circuit for controlling the output voltage of the inverter are provided, and the control circuit adjusts the output voltage of the inverter in accordance with the condition set by the output voltage setting means to reduce power consumption. The present invention realizes a power supply device that allows a user to select how to use the power supply device by saving power and extending the usage time of the power supply device.

In the invention described in claim 2, the control circuit is
The present invention realizes a power supply device that can be used for a long time as a configuration in which the output voltage of an inverter is adjusted according to the output of a battery capacity detection unit that detects the capacity of a battery.

According to the invention described in claim 3, the control circuit comprises:
(EN) A power supply device that can be used for a long time is realized as a configuration for controlling the waveform of the output voltage of the inverter according to the setting conditions of the output waveform setting means that sets the output waveform of the inverter.

According to the invention described in claim 4, the control circuit comprises:
When the output of the battery capacity detecting means becomes equal to or less than the set capacity, the waveform of the output voltage of the inverter is changed from a sine wave to a rectangular wave to realize a power supply device that can be used for a long time.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a power supply device that is a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the same operation.

FIG. 3 is a block diagram showing the configuration of a power supply device that is a second embodiment of the present invention.

FIG. 4 is an explanatory diagram showing the same operation.

FIG. 5 is a block diagram showing the configuration of a power supply device that is a third embodiment of the present invention.

FIG. 6 is an explanatory diagram showing the same operation.

FIG. 7 is an explanatory diagram showing the operation of the power supply device according to the fourth embodiment of the present invention.

FIG. 8 is a block diagram showing a configuration of a conventional power supply device.

[Explanation of symbols]

11 solar cells 12 converter 13 battery 14 Inverter 14a-14d switching element 14e Reactor 14f output capacitor 14g input capacitor 15 AC output outlet 16 Control circuit 17 Output voltage setting means 18 Battery capacity detection means 19 Output waveform setting means

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takahiro Miyauchi             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Kazuo Fujishita             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 5G003 AA06 BA01 DA18 GB06                 5H030 AS20 BB07 BB21 FF41

Claims (4)

[Claims] 1. A solar cell, a converter connected in parallel to the output of the solar cell, a battery connected to the converter, an inverter for converting DC power of the solar cell or the battery into AC power, and an inverter. And a control circuit for controlling the output voltage of the inverter, the control circuit adjusting the output voltage of the inverter according to the condition set by the output voltage setting means. 2. The power supply device according to claim 1, wherein the control circuit adjusts the output voltage of the inverter according to the output of the battery capacity detection means for detecting the capacity of the battery. 3. The power supply device according to claim 1, wherein the control circuit controls the waveform of the output voltage of the inverter according to the setting condition of the output waveform setting means that sets the output waveform of the inverter. 4. The control circuit changes the waveform of the output voltage of the inverter from a sine wave to a rectangular wave when the output of the battery capacity detecting means becomes less than or equal to a set capacity.
Power supply described in.