JP2022012723A - Power supply - Google Patents

Abstract

To enable the continued use of stable power while suppressing instantaneous interruption of power supply to a load and increase in heat quantity in a switch unit.SOLUTION: An autonomous driving control unit 30 having a constant threshold compares a detection result of a voltage detection circuit which detects the voltages of batteries 10a, 10b (first and second main batteries) with a threshold, so as to control a changeover of a switch unit 70 which is composed of a plurality of transistors 70a-70d in series connection, and a charging operation of a charging circuit which charges a battery 10a or 10b from a battery 20 (sub-battery).SELECTED DRAWING: Figure 1

Description

The present invention relates to a power supply device suitable for the use of natural energy.

In recent years, in consideration of environmental problems, the development of power supply devices using natural energy such as solar power and wind power has been promoted. However, the power generation method that uses natural energy has the disadvantages that the energy density is low, the output amount of the power generation is easily affected by the weather conditions, and stable power supply cannot be performed at all times. Various devices capable of supplying have been proposed.

As one of them, in Patent Document 1, electric energy from a solar cell is stored in a plurality of capacitors via a storage switch at the time of storage, and the storage switch is opened at the time of discharge to output the electric energy stored in the capacitors. In the configured power supply device, a capacitor switching means for switching a plurality of capacitors to series connection or parallel connection is provided, and in particular, a power supply for switching from a storage state to a discharge state when the terminal voltage of the capacitors reaches a voltage indicating a storage expiration state. We are proposing a device.

Japanese Unexamined Patent Publication No. 2006-042523

In the power supply device according to Patent Document 1 described above, since the capacitors are connected in series at the time of storage and switched to the parallel connection at the time of discharging, it is considered that the charging / discharging of the capacitors can be efficiently performed.

By the way, in this power supply device, switching between series connection and parallel connection of capacitors is performed by a mechanical power storage switch. In this way, if the series connection or parallel connection of the capacitors is switched by the mechanical power storage switch, the chattering that occurs when the power storage switch is switched may cause the power supply to the load to be interrupted momentarily.

In this case, it is considered that the occurrence of chattering can be suppressed by performing the mechanical storage switch by a switching element such as a transistor. However, in order to switch the flow of electric energy from the solar cell, it is necessary to increase the input impedance of the switching element. As described above, if the input impedance of the switching element is increased, the amount of heat generated by the switching element itself may increase.

Further, if the electric energy stored in the capacitor is from a solar cell, the energy supply from sunlight cannot be obtained as in bad weather or at night. In such a situation, if the stored electric power is exhausted, the electric power may not be used until the electric energy is supplied from the solar cell.

For these reasons, it is desired to develop a device capable of continuing stable power use while suppressing a momentary interruption of power supply to a load and an increase in heat generation amount of a switch.

The present invention has been made in view of such a situation, and an object of the present invention is to provide a power supply device capable of solving the above-mentioned problems.

The power supply device of the present invention uses the first main battery, the second main battery connected in parallel to the first main battery, the sub-battery, and the electric power from the sub-battery to be the first or the first. A charging circuit for charging the second main battery, an inverter for converting the electric power of the first or second main battery into AC, and a connection path between the first and second main batteries and a natural energy source. Automatic operation capable of controlling the switching of the switch unit for switching the connection path between the first and second main batteries, the inverter and the charging circuit, the switching of the switch unit, and the charging operation of the charging circuit. The switch unit includes a control unit, and is characterized in that the switch unit is composed of a plurality of transistors connected in series.
Further, a voltage detection circuit for detecting the voltage of the first and second main batteries is provided, and the switch unit connects the first main battery, the natural energy source, and the charging circuit in series. A plurality of connected first transistors and a plurality of second transistors connected in series connecting the second main battery, the natural energy source, the charging circuit, and the second main battery. , A plurality of series-connected third transistors connecting the first main battery and the inverter, and a plurality of series-connected fourth transistors connecting the second main battery and the inverter. The automatic operation control unit has a transistor, has a constant threshold value, and is based on any one of the first to fourth transistors based on a comparison result between the detection result of the voltage detection circuit and the threshold value. It is characterized in that a control signal is applied to the.
In the power supply device of the present invention, for example, the automatic operation control unit having a constant threshold value is a comparison result between the detection result and the threshold value of the voltage detection circuit that detects the voltage of the first and second main batteries connected in parallel. Based on this, it controls the switching of the switch unit composed of a plurality of transistors connected in series and the charging operation of the charging circuit for charging the first or second main battery with the power from the sub-battery.
Here, since the switch unit is composed of a plurality of transistors connected in series, chattering does not occur at the time of on / off switching.
Further, since the switch unit is composed of a plurality of transistors connected in series, the input impedance of each transistor can be reduced.
Further, since the automatic operation control unit controls the charging operation of the charging circuit that charges the first or second main battery with the electric power from the sub battery, the charging of the first or second main battery is insufficient at night or the like. Can be suppressed.

According to the power supply device of the present invention, since the switch unit is composed of a plurality of transistors connected in series, chattering does not occur at the time of on / off switching, so that the momentary interruption of the power supply to the load is suppressed. can. Further, since the switch unit is composed of a plurality of transistors connected in series, the input impedance of each transistor can be reduced, so that an increase in the amount of heat generated by each transistor can be suppressed. Further, since the automatic operation control unit controls the charging operation of the charging circuit for charging the first or second main battery with the electric power from the sub-battery, it is possible to suppress the insufficient charge of the first or second main battery. Even in a situation where the supply of energy from sunlight is cut off, such as at night, it is possible to continue to use electric power in a stable manner.

It is a circuit diagram for demonstrating one Embodiment of the power supply device of this invention.

Hereinafter, the details of one embodiment of the power supply device of the present invention will be described with reference to FIG.
The power supply device shown in FIG. 1 mainly includes batteries 10a, 10b, 20, an automatic operation control unit 30, a voltage detection circuit 40, an inverter 50, a charging circuit 60, and a switch unit 70. Although the details will be described later, the batteries 10a and 10b are used as the main battery, and the battery 20 is used as the sub-battery.

That is, the batteries 10a and 10b charge the electric power from the solar cell 90 and supply the charged electric power to the load. The batteries 10a and 10b are divided into two systems, but the battery 10a and 10b are not limited to this example and may be three or more systems. Further, as each of the batteries 10a, 10b and 20, a large capacity battery can be used. Further, the batteries 10a and 10b have a small capacity and can be used by connecting a plurality of batteries in parallel.

Further, although the details will be described later, reference numeral 20a indicates a switching circuit for connecting or disconnecting a path to and from the switch unit 70. Further, reference numeral 90 indicates a solar cell having a power generation capacity of, for example, 18V-100W. As the solar cell, a solar cell having an arbitrary power generation capacity may be used. Further, reference numeral D1 indicates a diode for preventing backflow.

Here, the + terminal of the battery 10a is connected to the emitters of the transistors 70a and 70c of the switch unit 70. The + terminal of the battery 10b is connected to the emitters of the transistors 70b and 70d of the switch unit 70. Further, the + terminals of the batteries 10a and 10b are connected to the + terminals of the battery 20 and the switching circuit 20a. The − terminals of the batteries 10a and 10b are connected to the − terminals of the voltage detection circuit 40, the solar cell 90, and the battery 20.

When the power from the solar cell 90 cannot be obtained from the solar cell 90 at night time or the like and the voltage of the battery 10a or 10b drops due to discharge to the load, the charged power is recharged to the battery 10a or 10b. It is used as a sub-battery for discharging. Further, the battery 20 is used as a drive source for the switching circuit 20a, the automatic operation control unit 30, the voltage detection circuit 40, the inverter 50, and the charging circuit 60. The + terminal and-terminal of the battery 20 are connected to the + terminal and-terminal of the charging circuit 60 via the switching circuit 20a. Further, the + terminal of the battery 20 is connected to the emitter side of the transistors 70a and 70b via the switching circuit 20a. Further, the − terminal of the battery 20 is connected to the − terminal of the solar cell 90.

The switching circuit 20a switches so that when the electric power from the solar cell 90 is charged to the battery 10a or 10b via the transistor 70a or 70b, the electric power from the solar cell 90 is charged to the battery 20. Further, the switching circuit 20a switches so as to disconnect the path between the transistor 70a or 70b when the electric power from the battery 20 is charged to the battery 10a or 10b.

The automatic operation control unit 30 controls the operations of the switching circuit 20a, the voltage detection circuit 40, the inverter 50, the charging circuit 60, and the switch unit 70. The automatic operation control unit 30 starts operation when a start setting switch (not shown) is turned on. The automatic operation control unit 30 has a constant threshold value (for example, 10V) set in advance by an activation setting switch or the like (not shown). The certain threshold value may be arbitrarily changed. The automatic operation control unit 30 compares the detection result of the voltage detection circuit 40 with the threshold value. The automatic operation control unit 30 will be described in detail later, but when it confirms that the voltage of the battery 10a or 10b has fallen below the threshold value due to discharge, the control signal A that causes the switch unit 70 to turn on any of the transistors 70a to 70d. Any one of ~ D is output via a wiring (not shown). The control signals A and B are positive voltages, and the control signals C and D are negative voltages. As a result, the switch unit 70 switches the battery 10a or 10b below the threshold value to charging, and switches the other battery 10a or 10b to discharging.

Further, although the details will be described later, the automatic operation control unit 30 confirms that the battery 10a or 10b has fallen below the threshold value in a situation where the energy supply from sunlight is cut off such as at night. , The switching circuit 20a, and the charging circuit 60 are operated. In this case, the automatic operation control unit 30 outputs any of the control signals A to D to the switch unit 70, and charges the battery 10a or 10b below the threshold value with the electric power from the battery 20. Further, the automatic operation control unit 30 operates the switching circuit 20a to switch so as to disconnect the path between the battery 20 and the transistor 70a or 70b. As a result, when the power from the battery 20 is charged to the battery 10a or 10b, the decrease in the charging capacity of the battery 20 caused by the voltage of the battery 20 itself can be suppressed, so that the power from the battery 20 can be transferred to the battery 10a or 10b. It can be charged reliably. In addition, in the case of charging from the battery 20 in a situation where the supply of energy from sunlight is cut off such as at night, even if the automatic operation control unit 30 can be controlled based on a preset timer. good.

The voltage detection circuit 40 detects the voltages of the battery 10a and the battery 10b under the control of the automatic operation control unit 30. The voltage detection circuit 40 may be omitted if, for example, the automatic operation control unit 30 has a voltage detection function. Under the control of the automatic operation control unit 30, the inverter 50 converts the 12V DC voltage of the battery 10a or 10b into an AC voltage of 100V and supplies it to the load. The charging circuit 60 outputs the electric power of the battery 20 to the switch unit 70 side under the control of the automatic operation control unit 30. As a result, although the details will be described later, the electric power of the battery 20 is charged to the battery 10a or 10b via the switch unit 70.

The switch unit 70 has NPN-type transistors 70a and 70b and PNP-type transistors 70c and 70d. Each of the transistors 70a, 70b, 70c, and 70d is composed of three combinations, and each of them is connected in series. The transistors 70a to 70d are not limited to a combination of three transistors. It may be a combination of two or a combination of four or more. Here, the transistors 70a and 70c correspond to switching between charging and discharging of the battery 10a. Further, the transistors 70b and 70d correspond to switching between charging and discharging of the battery 10b. Further, the transistors 70a and 70b have a role for charging. Further, the transistors 70c and 70d have a role for discharging.

In this way, by making each of the transistors 70a to 70d a combination of three connected in series, the input impedance of each of the three transistors 70a to 70d can be reduced. As a result, the amount of heat generated by each of the transistors 70a to 70d can be reduced. In this embodiment, the case where the switch unit 70 is composed of two systems of charging transistors 70a and 70b and discharging transistors 70c and 70d is shown, but there are three charging and discharging systems. The above may be applied. In this case, even if the number of solar cells 90 increases, problems such as heat generation in the switch unit 70 can be avoided, and the batteries 10a, the batteries 10b, and the like can be efficiently charged. Further, an element such as a capacitor may be provided on the base side of each of the transistors 70a to 70d, for example. In this case, for example, the influence of chattering generated on the automatic operation control unit 30 side or the like can be avoided.

Next, the operation of the power supply device having the above-described configuration will be described. In the following, in the switching of charge / discharge by the automatic operation control unit 30, as described above, the automatic operation control unit 30 compares the detection result of the voltage detection circuit 40 with the threshold value, and the battery 10a below the threshold value. Alternatively, the switch unit 70 is controlled so that one of 10b is switched to charging and the other is switched to discharging. This explanation shall be given as appropriate.

First, when the electric power from the solar cell 90 is charged to, for example, the battery 10a, the automatic operation control unit 30 applies a positive voltage control signal A to the bases of each of the three transistors 70a of the switch unit 70. Further, the automatic operation control unit 30 operates the switching circuit 20a to switch so that the path between the battery 20 and the switch unit 70 is connected. At this time, when the transistor 70a is turned on, the electric power from the solar cell 90 is supplied to the battery 10a, and the battery 10a is charged. At this time, the battery 20 is also charged.

Next, when the battery 10a is switched to charging, the automatic operation control unit 30 applies a negative voltage control signal D to the bases of the three transistors 70d of the switch unit 70, respectively. Further, the automatic operation control unit 30 operates the inverter 50. At this time, when the transistor 70d is turned on, the battery 10b is switched to discharge, and the electric power of the battery 10b is discharged to the inverter 50 side. Then, the inverter 50 converts the 12V DC voltage of the battery 10b into an AC voltage of 100V and supplies it to the load.

Next, when the discharging battery 10b is switched to charging the electric power from the solar cell 90, the automatic operation control unit 30 applies a positive voltage control signal B to the bases of each of the three transistors 70b of the switch unit 70. do. At this time, when the transistor 70b is turned on, the electric power from the solar cell 90 is supplied to the battery 10b, and the battery 10b is charged. At this time, the battery 20 is also charged.

Next, when the battery 10b is switched to charging, the automatic operation control unit 30 applies a negative voltage control signal C to the bases of each of the three transistors 70c of the switch unit 70. At this time, when the transistor 70c is turned on, the battery 10a is switched to discharge, and the electric power of the battery 10a is discharged to the inverter 50 side. Then, the inverter 50 converts the 12V DC voltage of the battery 10a into an AC voltage of 100V and supplies it to the load.

Next, a case where the electric power of the battery 20 is charged to the battery 10a or 10b will be described in a situation where the supply of energy from sunlight is cut off such as at night. First, the automatic operation control unit 30 determines whether or not the supply of energy from sunlight is cut off. In this case, the automatic operation control unit 30 can make a determination by confirming from the detection result of the voltage detection circuit 40 that the voltage of the battery 10a or 10b being charged does not rise for a certain period of time (for example, 5 minutes).

Here, it is assumed that the battery 10a is switched to charging and the battery 10b is switched to discharging. In this case, when the automatic operation control unit 30 confirms that the voltage of the battery 10a does not rise for a certain period of time based on the detection result of the voltage detection circuit 40, the detection result of the voltage detection circuit 40 with respect to the battery 10b and the threshold value are obtained. Compare and see if it is below the threshold. When the automatic operation control unit 30 confirms that the voltage of the battery 10b has fallen below the threshold value, the automatic operation control unit 30 operates the charging circuit 60. Further, the automatic operation control unit 30 operates the switching circuit 20a to switch so as to disconnect the path between the battery 20 and the switch unit 70. Further, the automatic operation control unit 30 applies a positive voltage control signal B to the base of the transistor 70b of the switch unit 70. At this time, when the transistor 70b is turned on, the electric power of the battery 20 obtained through the charging circuit 60 is supplied to the battery 10b, and the battery 10b is charged. Further, while the battery 10b is being charged, the automatic operation control unit 30 applies a negative voltage control signal C to the base of the transistor 70c of the switch unit 70. As a result, the electric power from the battery 10a switched to discharge is discharged to the inverter 50 side, and the inverter 50 converts the 12V DC voltage of the battery 10a into an AC voltage of 100V and supplies it to the load.

Next, after the battery 10a is switched to discharge, the automatic operation control unit 30 compares the detection result of the voltage detection circuit 40 with the threshold value and confirms whether or not the voltage has fallen below the threshold value. When the automatic operation control unit 30 confirms that the voltage of the battery 10a has fallen below the threshold value, the automatic operation control unit 30 operates the charging circuit 60. Further, the automatic operation control unit 30 applies a positive voltage control signal A to the base of the transistor 70a of the switch unit 70. At this time, when the transistor 70a is turned on, the electric power of the battery 20 obtained through the charging circuit 60 is supplied to the battery 10a, and the battery 10a is charged. Further, while the battery 10a is being charged, the automatic operation control unit 30 applies a negative voltage control signal D to the base of the transistor 70d of the switch unit 70. As a result, the electric power from the battery 10b switched to discharge is discharged to the inverter 50 side, and the inverter 50 converts the 12V DC voltage of the battery 10b into an AC voltage of 100V and supplies it to the load.

As described above, in the present embodiment, the automatic operation control unit 30 having a constant threshold value determines the detection result and the threshold value of the voltage detection circuit that detects the voltage of the batteries 10a and 10b (first and second main batteries). By comparison, it controls the switching of the switch unit 70 composed of a plurality of transistors 70a to 70d connected in series and the charging operation of the charging circuit for charging the battery 10a or 10b from the battery 20 (sub-battery). ..

Here, since the switch unit 70 is composed of a plurality of transistors 70a to 70d connected in series, chattering does not occur at the time of on / off switching, so that it is possible to suppress a momentary interruption of power supply to the load. Further, since the switch unit 70 is composed of a plurality of transistors 70a to 70d connected in series, the input impedance of each transistor 70a to 70d can be reduced, so that an increase in the amount of heat generated by each transistor 70a to 70d is suppressed. can. Further, since the automatic operation control unit 30 controls the charging operation of the charging circuit 60 that charges the battery 10a or 10b with the electric power from the battery 20 (sub-battery), it is possible to suppress the insufficient charging of the battery 10a or 10b. Even in a situation where the supply of energy from sunlight is cut off, such as at night, it is possible to continue to use electric power in a stable manner.

In this embodiment, the present invention can be applied not only to a power supply device using natural energy of sunlight but also to a power supply device using other natural energy such as wind power.

10a, 10b, 20 Battery 20a Switching circuit 30 Automatic operation control unit 40 Voltage detection circuit 50 Inverter 60 Charging circuit 70 Switch unit 70a to 70d Transistor 90 Solar cell A to D Control signal D1 Diode

Claims (2)

The first main battery and
A second main battery connected in parallel to the first main battery,
With the sub-battery
A charging circuit for charging the first or second main battery with electric power from the sub-battery,
An inverter that converts the power of the first or second main battery into alternating current,
A switch unit that switches between a connection path between the first and second main batteries and a renewable energy source, and a connection path between the first and second main batteries, the inverter, and the charging circuit.
It is provided with an automatic operation control unit capable of controlling the switching of the switch unit and the charging operation of the charging circuit.
The switch unit is a power supply device characterized by being composed of a plurality of transistors connected in series. A voltage detection circuit for detecting the voltage of the first and second main batteries is provided.
The switch part is
A plurality of first transistors connected in series connecting the first main battery, the natural energy source, and the charging circuit.
A plurality of second transistors connected in series connecting the second main battery, the natural energy source, the charging circuit, and the second main battery.
A plurality of series-connected third transistors connecting the first main battery and the inverter,
It has the second main battery and a plurality of fourth transistors connected in series to connect the inverter.
The automatic operation control unit has a constant threshold value, and applies a control signal to the base of any of the first to fourth transistors based on the detection result of the voltage detection circuit and the comparison result of the threshold value. The power supply device according to claim 1, wherein the power supply device is characterized by the above.

Images