JPH1146450A - Solar battery power unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power unit by which stable voltage can be obtained even in a day with less sunshine and stable voltage can be obtained for a long time, and which can effectively consume power charged in an accumulator. SOLUTION: An accumulating circuit 2 is provided with a plurality of accummulators 3 to which switch circuits 4 are connected each in series, and each of these switching circuits 4 is controlled for opening and closing, whereby each accumulator 3 is charged with the power of a solar battery 1 sequentially one by one so that the terminal voltage may be above the reference value, and also the voltage above the reference value is outputted from the accumulating circuit 2 by making the charged accumulators 3 output power sequentially one by one. Moreover, this power unit is so arranged that the voltage above the reference value is outputted from the accumulating circuit 2 by connecting a given number of accumulator 3 in series according to the terminal voltage, when the terminal voltage of charged all accumulators 3 fall under the reference value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar cell type power supply suitably used for a self-luminous road tack or a road sign using a light emitting diode or the like.

[0002]

2. Description of the Related Art Conventionally, a solar cell type power supply device used for a self-luminous road tack or a road sign using a light emitting diode or the like directly supplies power output from a solar cell to a load such as a light emitting diode. Instead, the power output from the solar cell is generally once charged in the power storage device, and the charged power is boosted to a constant voltage required by the load by a constant voltage circuit, and then supplied to the load. I have. As such a solar battery type power supply device, a device which charges all the power of a solar battery to one large-capacity power storage device or a plurality of small-capacity power storage devices connected in parallel to increase the capacity is used. Some power storage devices are charged at the same time. Further, in the solar battery type power supply device as described above, in order to boost the load voltage required by the load by the constant voltage circuit, the voltage input to the constant voltage circuit from the power storage device, that is, the terminal voltage of the power storage device is used. The load voltage must be equal to or higher than the reference value. If the terminal voltage of the power storage device becomes equal to or lower than the reference value and the voltage difference between the terminal voltage of the power storage device and the load voltage increases, the voltage cannot be boosted well.

[0003]

However, when the capacity of a power storage device is increased for both a device that stores all power in one power storage device and a device that stores power in a plurality of power storage devices connected in parallel at the same time, discharge occurs. The time until the battery becomes unusable, i.e., the time until the terminal voltage of the power storage device becomes lower than the reference value and the voltage cannot be boosted by the constant voltage circuit becomes longer, but conversely until the terminal voltage becomes higher than the reference value. It takes a long time to charge the battery, and there is a problem that the terminal voltage does not easily become a voltage higher than the reference value, especially during a day when the amount of sunlight is small, and a stable voltage cannot be obtained during that time. Conversely, when the capacitance is reduced, the time required for the terminal voltage to reach a voltage equal to or higher than the reference value is shortened. There is a problem that a stable voltage cannot be obtained.

[0004] In addition, even when power is consumed and the terminal voltage falls below the reference value, these power storage devices are not completely discharged and cannot be boosted well by a constant voltage circuit, but the power remains. And the remaining power is not effectively consumed.

Accordingly, the present invention solves the above-mentioned problems, provides a stable voltage even on a day with a small amount of sunshine, obtains a stable voltage for a long time, and effectively uses the electric power charged in the power storage device. It is an object of the present invention to provide a solar cell type power supply device which can be consumed for a long time.

[0006]

In order to achieve the above object, the present invention has the following arrangement. That is, in the solar battery type power supply device according to the present invention, the power output from the solar battery is charged in the power storage circuit, the output voltage from the power storage circuit is input to the constant voltage circuit, and the constant voltage circuit makes the voltage constant. A solar battery type power supply device adapted to be supplied to a load, wherein a plurality of power storage devices are provided in a power storage circuit, and a switch circuit is connected in series to each of the power storage devices, and controls opening and closing of each switch circuit. Thereby, each power storage device is charged with the power of the solar cell one by one so that the terminal voltage becomes a voltage equal to or higher than the reference value, and
When the charged power storage devices are output one by one in order and a voltage higher than the reference value is output from the power storage circuit, and when the terminal voltages of all the charged power storage devices become lower than the reference value, the terminal voltage becomes In this case, a predetermined number of power storage devices are connected in series, and a voltage equal to or higher than a reference value is output from the power storage circuit.

The reference value is a lower limit voltage in a range of an input voltage that can be boosted to a constant voltage by a constant voltage circuit, and depends on a load voltage required by a load and characteristics of the constant voltage circuit. However, the rated voltage of the power storage device used may be set as the reference value. If the voltage from the power storage circuit input to the constant voltage circuit is higher than the reference value, the voltage can be boosted to a constant voltage by the constant voltage circuit, and if the voltage is lower than the reference value, the voltage cannot be stably boosted.

According to the present invention, a plurality of power storage devices each having a switch circuit connected in series are provided in the power storage circuit, and by controlling the opening and closing of each switch circuit, the terminal voltage of each power storage device is equal to or higher than a reference value. The power of the solar cells is charged one by one so that the voltage of the solar battery becomes one, and the charged power storage devices are sequentially output one by one so that a voltage equal to or higher than the reference value is output from the power storage circuit. I have.

Therefore, even on a day when the amount of sunlight is small, the terminal voltages of all the power storage devices do not become voltages higher than the reference value, and each power storage device is connected to another power storage device in accordance with the amount of sunlight. Power storage devices are charged one by one so as to have a voltage equal to or higher than the reference value one by one, and the power storage devices thus charged above the reference value are switched from one power storage device according to the load consumption. Since the charging power is output from the power storage circuit to the other power storage devices one by one in sequence, a stable voltage can be obtained even on a day with a small amount of sunlight, and a stable voltage can be obtained for a long time.

When the terminal voltages of all charged power storage devices become equal to or lower than the reference value, or when the terminal voltages are equal to or lower than the reference value, a predetermined number of power storage devices are connected in series in accordance with the terminal voltages, and are connected in series. Since the voltage is output from the power storage circuit, even if the power of all the power storage devices is consumed and the terminal voltage becomes equal to or lower than the reference value, the power remaining in these power storage devices remains in series. The power is effectively consumed by being connected to a voltage higher than the reference value and being output again from the power storage circuit.

In the present invention, each switch circuit connected in series to the power storage device detects an output voltage from the power storage circuit and / or a load-side voltage supplied to the load from the constant voltage circuit, and detects the voltage. It is preferable to control the opening and closing based on the applied voltage.

That is, in the case of controlling the opening and closing of each switch circuit by detecting the output voltage from the power storage circuit, the output voltage from the power storage circuit is detected by the output voltage detection circuit and the detected output voltage is set to a predetermined reference. When the output voltage from the power storage circuit becomes lower than the reference value as compared with the value, each switch circuit may be opened and closed to control the output voltage from the power storage circuit to be higher than the reference value.

In the case of controlling the opening and closing of each switch circuit by detecting the voltage on the load side supplied to the load from the constant voltage circuit, the voltage on the load side supplied to the load from the constant voltage circuit is detected by the load voltage detection circuit. The detected voltage on the load side is detected and compared with a preset load voltage.When the load voltage is lower than the load voltage, the output voltage from the power storage circuit is lower than the reference value. It may be controlled so as to be opened and closed so that the output voltage from the power storage circuit becomes equal to or higher than the reference value.

In order to more accurately control the opening and closing of each switch circuit, the output voltage from the power storage circuit and the load voltage supplied to the load from the constant voltage circuit are detected. May be controlled so that the output voltage from the power storage circuit is equal to or higher than the reference value by opening and closing each switch circuit.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a circuit configuration diagram showing one embodiment of the present invention, and FIGS. 2 to 5 are circuit configuration diagrams showing an operation example of a switch circuit in a power storage circuit.

In the drawings, reference numeral 1 denotes a solar cell, and a suitable solar cell such as a monocrystalline or polycrystalline crystalline silicon solar cell, an amorphous amorphous silicon solar cell, or a compound semiconductor solar cell is used. It is not limited.

Reference numeral 2 denotes a power storage circuit for charging the electric power output from the solar cell 1. A plurality of power storage devices 3 are used, and a switch circuit 4 is connected to each power storage device 3 in series. The power storage device 3 generally uses a storage battery such as a lead storage battery or a Ni-Cd battery, or a capacitor such as an electric double layer capacitor, and generally has a capacity smaller than the amount of power generated by the solar cell 1. The total capacity of the plurality of power storage devices 3 is set to be approximately equivalent to the amount of power generated by the solar cell 1, but is not particularly limited.
Are charged one by one without charging them at the same time, so long as they can charge one power storage device 3 as quickly as possible.

Reference numeral 5 denotes a backflow prevention diode connected between the solar cell 1 and the power storage circuit 2, such as at night when the voltage output from the solar cell 1 becomes lower than the voltage of the power storage circuit 2.
This is for preventing a current from flowing backward from the power storage circuit 2 to the solar cell 1 side.

Reference numeral 6 denotes an output voltage detection circuit connected in parallel with the power storage circuit 2, which detects an output voltage from the power storage circuit 2 and compares it with a preset reference value.

Reference numeral 7 denotes a constant voltage circuit, which includes a switching circuit 71, a coil 72, a diode 73, and a capacitor 74.
It consists of. The constant voltage circuit 7 controls the voltage fluctuation of the charging power input from the power storage circuit 2 by a transistor or the like, stabilizes the voltage, constantly boosts the voltage to a constant voltage, and supplies the voltage to a load 9 described later. In order to boost the voltage by the constant voltage circuit 7 to the load voltage required by the load 9, the power storage circuit 2
The input voltage must be equal to or higher than a predetermined reference value with respect to the load voltage. When the voltage from the power storage circuit 2 becomes equal to or lower than the reference value and the voltage difference from the load voltage increases, the voltage can be boosted well. become unable. The reference value is set according to the load voltage required by the load 9 and the characteristics of the constant voltage circuit 7, but may be set to the rated voltage of the power storage device 3.

Reference numeral 8 denotes a load voltage detection circuit which detects a voltage on the load side supplied to the load 9 from the constant voltage circuit 7, and determines a load voltage set in advance according to the load 9 to operate the load 9. Be compared.

The output voltage from the power storage circuit 2 is compared with a preset reference value by the output voltage detection circuit 6 and the load voltage detection circuit 8, and the load supplied to the load 9 from the constant voltage circuit 7. The side voltage is compared with a preset load voltage, whereby each of the switch circuits 4 is controlled to open and close.

By controlling the opening and closing of each switch circuit 4, each power storage device 3 transfers one power storage device 3 to another power storage device 3 such that the terminal voltage becomes equal to or higher than the reference value.
The power of the solar cells 1 is charged one by one, and the charged power storage devices 3 are output one by one in order, and a voltage equal to or higher than the reference value is output from the power storage circuit 2. This voltage is input to the constant voltage circuit 7, boosted to a load voltage, and supplied to the load 9.

When the terminal voltages of all the charged power storage devices 3 are equal to or lower than the reference value, or are equal to or lower than the reference value,
Further, a predetermined number of power storage devices 3 are connected in series according to the terminal voltage, and a voltage equal to or higher than a reference value is output from power storage circuit 2. This voltage is input to constant voltage circuit 7, and is boosted to a load voltage to be loaded. 9.

Reference numeral 9 denotes a load such as a light emitting diode including a control circuit. The load 9 is boosted to a load voltage by the constant voltage circuit 7 according to the load 9, and can operate stably with the supplied voltage.

Next, an example of an operation procedure of the switch circuit 4 which is opened and closed by the output voltage detection circuit 6 and the load voltage detection circuit 8 as described above will be described with reference to FIGS.

At the time of charging, first, the first switch circuit 41 and the other second to sixth switch circuits 42 to 46 are connected to each other as shown in FIG.
Thus, only the first power storage device 31 is connected to the solar cell 1 and charged. Next, as shown in FIG. 3, by switching between the first switch circuit 41 and the fourth switch circuit 44, the first power storage device 31 is disconnected from the solar cell 1, and only the second power storage device 32 is connected to the solar cell 1 for charging. Let it. Thus, the first to sixth switch circuits 41 to 46
Is appropriately switched, the first power storage device 31 to the second power storage device 32, and the third power storage device 3
The power of the solar cell 1 is charged such that the terminal voltage becomes equal to or higher than the reference value, one by one in order.

When supplying the charged power to the load,
As in the case of the charging, first, only the first power storage device 31 is connected as shown in FIG. 2 and the power of the first power storage device 31 is output, so that a voltage equal to or higher than the reference value is output from the power storage circuit 2,
This voltage is input to the constant voltage circuit 7, boosted to a load voltage, and supplied to the load 9. Next, the first power storage device 31
Is consumed by the load 9, and when the output voltage detection circuit 6 and the load voltage detection circuit 8 determine that the output voltage of the power storage circuit 2 has become equal to or lower than the reference value, the first power storage device 31 is turned off as shown in FIG. Disconnect and connect only the second power storage device 32,
By causing the power of the second power storage device 32 to be output, a voltage equal to or higher than the reference value is subsequently output from the power storage circuit 2. In this way, the first to sixth switch circuits 41 to 46 are appropriately switched in the same manner as when charging, and the first to sixth switch circuits 41 to 46 are sequentially connected one by one from the first power storage device 31 to the second power storage device 32 and the third power storage device 33. By outputting the voltage, the voltage equal to or higher than the reference value is continuously output from the power storage circuit 2, and the voltage is increased to the load voltage by the constant voltage circuit 7 and supplied to the load 9. In the present embodiment, the first power storage device 31 is sequentially output from the same first power storage device 31 as at the time of charging.
4, the first power storage device 31 may be output last.

Then, all charged power storage devices 31 to 3
4 is consumed, and when the terminal voltages of all the power storage devices 31 to 34 become lower than the reference value, for example, as shown in FIG.
By appropriately switching the switch circuits 41 to 46, the first power storage device 31 and the second power storage device 32, and the third power storage device 33 and the fourth
The power storage device 34 is connected in series, the series voltage is higher than the reference value, a voltage higher than the reference value is output from the power storage circuit 2, the voltage is increased to the load voltage by the constant voltage circuit 7, and the load 9 is supplied to the load 9. Let it be supplied. Next, when power is consumed from this state and the output voltage from the power storage circuit 2 becomes equal to or lower than the reference value, the first to fourth power storage devices 31 to 34 are all connected in series again as shown in FIG. The voltage equal to or higher than the reference value is further output from the power storage circuit 2 so that the series voltage becomes equal to or higher than the reference value.

The power of the power storage device 3 is thus consumed,
When one power storage device 3 cannot output a voltage higher than the reference value from the power storage circuit 2, a predetermined number of power storage devices 3 are appropriately selected according to the terminal voltage of the power storage device 3, and a voltage higher than the reference value is selected. By connecting them in series as follows, a voltage equal to or higher than the reference value can be continuously output from the power storage circuit 2, and the voltage can be boosted to the load voltage by the constant voltage circuit 7. In the above embodiment, four power storage devices 3 are provided, but the number is not particularly limited. Note that it is preferable to use a self-holding contact for the switch circuit 4 and use a low power consumption circuit that does not require power consumption for state holding.

[0031]

According to the present invention, a plurality of power storage devices each having a switch circuit connected in series are provided in the power storage circuit, and by controlling the opening and closing of each switch circuit, the terminal voltage of each power storage device is set to a reference voltage. 1 so that the voltage is
The power of the solar cells is charged one by one, and the charged power storage devices are output one by one so that a voltage higher than a reference value is output from the power storage circuit.

Therefore, even on a day with a small amount of sunlight, the terminal voltages of all the power storage devices do not become voltages higher than the reference value. Power storage devices are charged one by one so as to have a voltage higher than the reference value one by one, and the power storage devices thus charged above the reference value are charged from one power storage device in accordance with the load consumption. Since the charging power is output from the power storage circuit to the other power storage devices one by one in sequence, a stable voltage can be obtained even on a day with a small amount of sunlight, and a stable voltage can be obtained for a long time.

When the terminal voltages of all charged power storage devices become equal to or lower than the reference value, or when the terminal voltages are equal to or lower than the reference value, a predetermined number of power storage devices are connected in series in accordance with the terminal voltages, and when the terminal voltages exceed the reference value. Since the voltage is output from the power storage circuit, even if the power of all the power storage devices is consumed and the terminal voltage becomes equal to or lower than the reference value, the power remaining in these power storage devices remains in series. It is effectively consumed by being connected and having a voltage equal to or higher than the reference value and output from the power storage circuit.

[Brief description of the drawings]

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

FIG. 2 is a circuit configuration diagram illustrating an operation example of a switch circuit in a power storage circuit.

FIG. 3 is a circuit configuration diagram illustrating another operation example of the switch circuit in the power storage circuit.

FIG. 4 is a circuit configuration diagram showing another operation example of the switch circuit in the power storage circuit.

FIG. 5 is a circuit configuration diagram illustrating another operation example of the switch circuit in the power storage circuit.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 solar cell 2 power storage circuit 3 power storage device 31 first power storage device 32 second power storage device 33 third power storage device 34 fourth power storage device 4 switch circuit 41 first switch circuit 42 second switch circuit 43 third switch circuit 44 fourth Switch circuit 45 Fifth switch circuit 46 Sixth switch circuit 5 Backflow prevention diode 6 Output voltage detection circuit 7 Constant voltage circuit 71 Switching circuit 72 Coil 73 Diode 74 Capacitor 8 Load voltage detection circuit 9 Load

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H02J 7/35 H02M 3/07 H02M 3/07 H01L 31/04 K

Claims (2)

[Claims] An electric power output from a solar battery is charged in a power storage circuit, an output voltage from the power storage circuit is input to a constant voltage circuit, and a constant voltage is supplied to the load by the constant voltage circuit. A solar-powered power supply,
In the power storage circuit, a plurality of power storage devices are provided, and a switch circuit is connected to each power storage device in series, and by controlling the opening and closing of each switch circuit, the terminal voltage of each power storage device becomes equal to or higher than the reference value. As described above, the power of the solar cells is charged one by one, and the charged power storage devices are output one by one so that the voltage equal to or higher than the reference value is output from the power storage circuit. When the terminal voltage of the power storage device is equal to or lower than the reference value, a predetermined number of power storage devices are connected in series according to the terminal voltage, and a voltage higher than the reference value is output from the power storage circuit. Solar power supply. Detecting an output voltage from a power storage circuit and / or a load-side voltage supplied to a load from a constant voltage circuit;
2. The solar cell type power supply according to claim 1, wherein the switching circuit is controlled to open and close based on the detected voltage.