JP2001249727A - Photovoltaic power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photovoltaic power generation system capable of operating a display unit even at nights in an extremely simple device constitution. SOLUTION: This system is provided with a system linking inverter 3 for controlling a power outputted from a solar battery array 1 for performing photoelectric conversion by connecting plural solar battery modules in serial parallel and a display unit 4 having a display means 8 for displaying the generated electric power of the solar battery array 1 from the system linking inverter 3 and a control circuit having a microprocessor. The display unit 4 is provided with a detecting means being a means for detecting the presence or absence of the power generation of the solar battery array 1 and at least one power storage means being a means for storing a power necessary for driving the display unit 4 and an inputting means 9 being a means for allowing a user to instruct the classification of display at the display means 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photovoltaic power generation system having a display unit for displaying a power generation amount and the like.

[0002]

2. Description of the Related Art As a typical photovoltaic power generation system, there is a grid interconnection system. In general, this system collects DC power from a plurality of solar cell strings (a plurality of solar cell modules wired in series and / or in parallel) in a current collection box to connect to a grid-connected inverter as a power conversion means. , Converted into AC power, and output to the system. The instantaneous generated power, the integrated generated power amount, and the like at that time are displayed on a display unit that is a display unit connected to the grid-connected inverter.

[0003] Conventionally, as a configuration example of a power supply unit of a system interconnection inverter and a display unit, for example, Japanese Patent Laid-Open Publication
No. 0661 is known. As described in this publication, there is an apparatus in which a grid-connected inverter and a display unit are connected by a cable, and power is supplied to the display unit by a control power supply built in the grid-connected inverter. In this configuration, as the input power source for the control power source, there are a type using a solar cell module and a type using a commercial system.

[0004] Among them, the solar battery module of the type using the input power source receives control power only from the solar battery module, so that there is no power consumption at night, when the sun is not illuminated, and power saving is achieved. Excellent as a system.

Further, as disclosed in Japanese Patent Application Laid-Open No. 9-215339, a system for driving a display unit by providing a dedicated solar cell module for the display unit has been considered.

[0006]

However, there is the following problem in the case where the control power supply of the system interconnection inverter is driven by using the solar cell module as the input power supply to supply power to the display unit.

[0007] When the solar cell module does not generate power, such as at night, the control power supply of the grid-connected inverter is not driven, and the display unit does not operate. Therefore,
For example, if a housekeeper with a photovoltaic system (user of a photovoltaic system) returns home at night,
The inconvenience that the accumulated power generated in one day cannot be confirmed occurs.

[0008] On the other hand, in the case where the control power supply of the grid-connected inverter is driven by using the commercial power supply as an input power supply to thereby operate the display unit, the display unit is operated even when the solar cell module does not generate power, such as at night. Is possible, but consumes a lot of power for a low frequency of use.

In addition, since the control power supply of the grid-connected inverter has a power capacity for controlling all of the grid-connected inverter, there is a disadvantage that the conversion efficiency is poor at a small power used in the display unit. . Generally, for a 3kW class grid-connected inverter for residential use, 1
A control power supply of about 0 to 30 W is often provided. On the other hand, the power consumption of the display unit is less than 3 W in most cases. At this time, the efficiency of the control power supply is drastically reduced to about 50 to 60%, and the loss is about 3 W.

Further, in the case of using a dedicated solar cell module provided in the display unit, it must be installed in a relatively bright place. When driving a unit with large power consumption, disadvantages such as the necessity of using a large solar cell module arise.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has a display unit of a grid-connected inverter that can operate the display unit even at night with a very simple device configuration. The task is to provide

[0012]

In order to solve the above problems, a photovoltaic power generation system according to the present invention comprises a solar cell array, a power control device for controlling electric power photoelectrically converted by the solar cell array, and In a solar power generation system having a display unit having a display unit and a control circuit for displaying a power generation amount of the solar cell array from a power control device, the display unit indicates the power generation amount of the solar cell array from the power control device. Input means for instructing a display type, the display unit includes detection means for detecting the presence or absence of power generation by the solar cell array, and power storage means for storing power required to drive the display unit. Features.

[0013] In the present invention, the power mode of the power required to use the display unit is set by the solar cell array based on an input from the input means or based on a detection signal from the detection means. It is preferable to have switching means for switching to a normal operation mode when the power is being supplied or to a power saving mode when the solar cell array is not generating power.

The power storage means comprises first and second power storage means for storing power, and comprises the first power storage means and a diode connected in a forward direction to a negative pole of the first power storage means. A first power supply path, and a second power supply path including a diode connected in a forward direction to the second power storage means and a positive pole of the second power storage means; Placed between the power supply paths,
A serial / parallel switching means for switching the first power storage means and the second power storage means in series or in parallel, wherein the first power supply path and / or the second power supply path And control means for controlling the output of the control means, and the series / parallel switching means and / or the control means can be driven according to a detection signal from the detection means.

Further, the power storage means stores the power.
And at least three power supply paths comprising at least three power storage means, and at least three power storage means, and at least three power supply paths comprising diodes connected in a forward direction to the at least three power storage means. The series-parallel switching means is disposed between each, and has control means for controlling the output of the power supply path of part or all of the three or more power supply paths, the detection signal from the detection means The series / parallel switching means and / or the control means can be driven accordingly.

Further, the power storage means includes a first power storage means for driving the control circuit in the display unit and a second power storage means for driving a display element in the display unit.
It is preferable that the power storage device includes two power storage devices, and the first power storage device and the second power storage device have different storage voltages.

It is preferable that the power storage means is an electric double layer capacitor. Further, the photovoltaic power generation system includes a calculating means for performing a calculation for displaying the display type on the display means, a storing means for storing the display type calculated by the calculating means in a memory, and a timer for measuring time. It is preferable that the display type includes a power generation amount, an integrated power amount, and a total integrated power amount, and the display of the display type on the display unit is switched by the input unit.

[0018]

The power supply to the display means is configured such that power can be supplied from the power control device using the solar cell as a power source and also from the power storage means provided in the display unit, and further, the display switch provided on the display unit is operated. Thus, the display means operates even when the solar cell is in a non-power generation state, such as at night, so that the accumulated power generation amount and the like can be constantly checked. In the daytime or the like, the display means can be supplied with the output power of the solar cell as a supply source.

[0019]

Next, embodiments of the present invention will be described with reference to the drawings. Embodiment 1 (Configuration Example of Solar Power Generation System) FIG. 1 is a schematic configuration diagram of a solar power generation system used in the present embodiment. Reference numeral 1 denotes a solar cell array in which a plurality of solar cell modules are connected in series and / or in parallel. There are various types of solar cells, solar cell modules and their installation forms. In the present embodiment, these types may be of any type.

Reference numeral 2 denotes a current collecting box having a current collecting function for collecting the output of the solar cell array 1. Reference numeral 3 denotes a system interconnection inverter that is a power control device that converts DC power from the current collection box 2 into AC and outputs the converted AC power to the AC system. Reference numeral 4 denotes a display unit for displaying a power generation amount of the solar cell array 1 and the like, which is a system interconnection inverter.

Reference numeral 5 denotes a connection cable for transmitting the amount of power generated by the system interconnection inverter to the display unit. One end of the connection cable 5 can be connected to a connector that outputs the generated power information of the grid interconnection inverter 3 and the display unit drive power supply power, and the other end can be connected to the input connector of the display unit 4. Reference numeral 6 denotes an AC distribution panel provided between the system interconnection inverter 3 and the AC system 7, and has an opening / closing function capable of opening and closing the current generated from the system interconnection inverter 3.

Reference numeral 8 denotes a display unit for displaying the amount of power generated by the solar cell array 1 from the grid-connected inverter 3 in the display unit 4. Reference numeral 9 denotes an input unit on the display unit 8 of the display unit 4 for instructing a display type indicating a power generation amount or the like of the solar cell array 1 by a user.

(Example of Internal Configuration of Grid-Connected Inverter 3) FIG. 2 shows the internal configuration of the grid-connected inverter 3 used in the first embodiment. In FIG. 2, the flow of electric power is indicated by a solid line, and the flow of a signal is indicated by a dotted line. Reference numeral 11 denotes an input terminal for inputting the generated power of the solar cell array 1 (FIG. 1) via the current collection box 2 (FIG. 1). Reference numeral 12 denotes an input-side noise filter including a capacitor and the like, and reference numeral 13 denotes an orthogonal transformation circuit including a smoothing capacitor, a reactor, a diode, a switching element, and the like.

Reference numeral 14 denotes an interconnection switch for switching between connection and disconnection with the AC system, reference numeral 15 denotes an output-side noise filter constituted by a capacitor or the like, and reference numeral 16 denotes an output terminal for outputting AC power to the distribution board 6. 17 is an AC voltage detector and 18 is an AC current detector.

Reference numeral 19 denotes a control circuit composed of a microprocessor or the like. The control circuit 19 performs various controls and protection of the chopper circuit and the inverter circuit of the orthogonal transform circuit 13. Further, the control circuit 19 includes the AC voltage detector 17
And a calculating means for calculating the AC power generated by the grid interconnection inverter 3 based on the voltage and the current detection value of the AC current detector 18. The calculated generated power (displayed power, integrated power, total integrated power, etc.) as the display type is output to the output connector 20 as generated power data.

Reference numeral 21 denotes a DC / DC converter that inputs DC power from the solar cell array 1 and the current collection box 2 (both shown in FIG. 1) and outputs DC power for driving the control circuit 19. D
The C / DC converter 21 is configured to also supply power for driving the display unit 4 (FIG. 1), and outputs power for driving to the output connector 20.

(Example of Internal Configuration of Display Unit 4) Embodiment 1
FIG. 3 shows the internal configuration of the display unit 4 used in the embodiment.
Also in FIG. 3, the flow of electric power is indicated by a solid line, and the flow of a signal is indicated by a dotted line. Reference numeral 31 denotes an input connector for inputting a display type (a power generation amount, an integrated power amount, a total integrated power amount, etc.) such as a power generation amount from the grid-connected inverter 3 (FIG. 1) by the solar cell array. Reference numeral 32 denotes a circuit including power storage means for storing driving power for the display unit 4 at night, the details of which are shown in FIG. Reference numeral 33 denotes a control circuit (control means) including a microprocessor and the like provided in the display unit 4. Reference numerals 34, 35, and 36 denote push switches, which are input means for the user to operate display contents, respectively. Reference numeral 34 denotes a night display switch, reference numeral 35 denotes a power mode switch, and reference numeral 36 denotes a clear switch. 38 is a display LED which is a display means for displaying a display type such as a power generation amount.
(Light Emitting Diode), 37
Is a drive circuit for driving the display LED.

The generated power data input from the input connector 31 is sent to the control circuit 33, and the driving power
2, control circuit 33, display LED 38, display L
It is sent to the ED drive circuit 37.

(Example of Configuration of Circuit 32) FIG. 4 shows an example of the configuration of the circuit 32 in FIG. The circuit 32 has a detecting unit for detecting the voltage of the drive power supply from the grid-connected inverter 3 and a power storage means for storing the drive power supply from the grid-connected inverter 3 (FIG. 1).

Reference numeral 41 denotes a drive power input terminal which is input from the system interconnection inverter 3 (FIG. 1) via the connection cable 5 (FIG. 1) and the input connector 31 (FIG. 3). Reference numeral 42 denotes a drive power supply output terminal that outputs drive power supply to the control circuit 33 and the LED drive circuit 37 in the display unit 4 (FIG. 3). 43 is a backflow prevention diode, and 44 is an electric double layer capacitor.

The drive power input from the input terminal 41 is connected to the electric double layer capacitor 44 via the backflow prevention diode 43. By connecting the backflow prevention diode 43 in this way, when the solar cell does not generate power at night, the stored charge of the electric double layer capacitor 44 as the storage means is prevented from flowing back to the input terminal 41 side and discharged. be able to.

Reference numeral 45 denotes an input voltage detection circuit, which is a detection means for detecting the presence or absence of power generation by the solar cell array 1 (FIG. 1) and the system interconnection inverter 3 (FIG. 1). In this embodiment, the input terminal voltage is divided by resistance.
The resistance used for the resistance voltage division should be as high as possible to reduce power consumption. The detected voltage is sent to the microprocessor in the control circuit 33 (FIG. 3) via the output terminal 46. When the detection voltage decreases, the control circuit 33
(FIG. 3) is configured to shift to a power saving (low power consumption) mode.

Further, the system interconnection inverter 3 of this embodiment
Since the drive power from (FIG. 1) is 15 V and the drive power of the microprocessor in the control circuit 33 (FIG. 3) is 5 V, a DC / DC converter 47 as a DC transformer is provided.

Display unit 4 used in this embodiment (FIG. 1)
In the normal operation mode, the average power consumption was 200 mW. Therefore, in the specification in which the night check is performed only once or twice, about 18 W is required to light the display unit 4 for one minute.
s of power is required. In this embodiment, in order to satisfy this, an electric double layer capacitor 44 of 12 V and 0.5 F is used.

The reason for using the electric double layer capacitor 44 will be described below. (1) Since the charge and discharge cycle is infinite, replacement is not required unlike a secondary battery or the like. (2) It can be made smaller and more compact than using an aluminum electrolytic capacitor. (3) If a failure occurs, an open mode failure occurs and it is safe.
If a failure occurs in the short mode when a secondary battery or the like is used, the display unit 4 (FIG. 3) cannot be used even in the daytime.

(Example of Operation of Display Unit 4) FIG. 5 shows an external view of the display unit 4. In FIG. 5, reference numeral 38 denotes a display LED as display means, 34 denotes a night display switch, and 35 denotes a display LED.
Is a power mode changeover switch which is a power mode changeover means, and 36 is a clear switch.

The display unit 4 is usually installed at a position that is easy for the user to see, and can display the current power generation amount, the integrated power amount, the total integrated power amount, and the like (display type). By pressing the power mode changeover switch 35 provided on the display unit 4, the power generation amount, the integrated power amount, and the total integrated power amount are switched and displayed on the display LED 38. The display contents of the generated power, the integrated power, and the total integrated power are shown below. -Power generation (unit: kW): The current power generation from the solar cell array in the grid-connected inverter is displayed.・ Integrated power (unit kWh): Generated power from the clear switch to the present is integrated and displayed.・ Total integrated power (unit: kWh): Total power generated from the operation start date of the grid-connected inverter to the present is integrated and displayed.

(Example of state transition of normal operation of display unit)
FIG. 6 is a state transition diagram showing an example of a transition of the normal operation of the display unit 4 (FIG. 5). The display type of the generated power to be displayed is switched by the power mode changeover switch 35 (FIG. 5), and is sequentially switched from the power generation amount display → the integrated power amount display → the total integrated power amount display → the power generation amount display.

Further, in the display state of the power generation amount or the total integrated power amount, even if the clear switch 36 is pressed, the operation is not affected. However, if the clear switch 36 is pressed in the display state of the accumulated electric energy, the accumulated electric energy display is cleared (return to zero).

In the above configuration, the system interconnection inverter 3
By transmitting the power generation amount data from (FIG. 1) to the display unit 4 (FIG. 1), various data are updated.
3, the control circuit 33 (FIG. 3) in the display unit 4 recognizes the current power generation amount (unit: kW) based on the power generation amount data transmitted from the grid interconnection inverter 3. Also,
In the control circuit 33, the power generation amount of the grid-connected inverter 3 is added, and the total integrated power amount (unit k
Wh) is obtained and sequentially stored in a non-volatile memory (not shown) provided in the control circuit 33 by the storage means. Similarly, by adding the amount of power generation, the integrated power amount during the period from when the clear switch 36 (FIG. 5) is pressed is obtained, and is sequentially stored in a nonvolatile memory (not shown) provided in the control circuit 33 by the storage unit. I do.

As described above, in FIG. 3, the control circuit 33 (FIG. 5) in the display unit 4 controls the power generation amount, the integrated power amount, the total integrated power amount, etc. Display LED
The display LED drive circuit 37 is driven so as to display on the display 38.

(Example of State Transition of Power Mode of Display Unit) While the above-described three display modes are provided, the display unit 4 (FIG. 5) has two power modes: a normal operation mode and a power saving mode. The mode changes according to a predetermined condition.

The normal operation mode is a mode in the daytime when the solar battery is generating power and the grid-connected inverter 3 (FIG. 1) is operating. This is a mode for performing a display switching operation.

On the other hand, the power saving mode is a mode in which the solar battery is not generating power at night and the system interconnection inverter 3 is stopped, and the display LED 38 (FIG. 3) is turned off. The power consumption of the display unit 4 (FIG. 1) is suppressed to a minimum by, for example, putting the microprocessor in (FIG. 3) into a sleep state.

FIG. 7 is a state transition diagram showing an example of transition of the power mode of the display unit 4 (FIG. 1). Now, it is assumed that the display unit 4 is in the normal working mode. After the power supply from the grid interconnection inverter 3 (FIG. 1) is stopped, a predetermined time (t1) is measured by the timing unit in the control unit 33 (FIG. 3).
When the continuation is detected, the display unit 4 shifts to the power saving mode by the power mode switching unit. The display of the display LED 38 (FIG. 3) is turned off, and the microprocessor in the control circuit 33 is put into the sleep state.
In the present embodiment, t1 = 1 minute (arrow).

In the power saving mode, when power supply is started from the grid interconnection inverter 3 (FIG. 1), the voltage detection circuit 4
5 (FIG. 4) rises and the control circuit 33 (FIG. 3)
The microprocessor inside detects the rise of the driving power from the grid interconnection inverter 3. Thereby, the microprocessor returns from the sleep state to the normal state, and the display unit 4 (FIG. 5) shifts to the normal operation mode (arrow).

When it is desired to check the integrated power amount, the total integrated power amount, and the like in the power saving mode, the night display switch 34 (FIG. 5) is pressed. As a result, the microprocessor returns from the sleep state to the normal state, and the display unit 4 (FIG. 5) shifts to the normal operation mode (arrow).

In this embodiment described above, when it is desired to check the integrated power amount and the total integrated power amount at night, the display unit 4 (FIG. 5) is operated in the normal operation mode when the night display switch 34 (FIG. 5) is pressed. And the displayed contents can be confirmed. Also, at this time, since the output of the voltage detection circuit 45 (FIG. 4) is equal to or less than the predetermined value, the display unit 4 switches to the power saving mode again after t1 = 1 minute.

In the solar power generation system shown in FIG. 1 of the present embodiment, in the daytime, when the solar cell array 1 (FIG. 1) is generating power, the drive power supply from the grid-connected inverter 3 (FIG. 1) is used. Electric double layer capacitor 44 (FIG. 4)
Is charged.

At night, when it is detected that the solar cell array 1 has stopped generating power and the drive power supply from the grid-connected inverter 3 (FIG. 1) has stopped feeding, the control circuit 33
(FIG. 3) shifts to the power saving mode to suppress the use of the stored power of the electric double layer capacitor 44 (FIG. 4).

When detecting that the night display switch 34 (FIG. 3) is pressed, the control circuit 33 (FIG. 3) switches to the normal mode for a certain period of time using the stored power of the electric double layer capacitor 44 (FIG. 4). In addition, it is possible to confirm the integrated power amount, the total integrated power amount, and the like.

In this embodiment, the night display switch 34 (FIG. 3) is separately provided.
It is also possible to reduce the number of switches in the display unit 4 (FIG. 3) by sharing the function of 4 with other switches. For example, in FIG.
One example is a method in which the role of the night display switch 34 is also used.

In the configuration of this embodiment, the display unit 4 (FIG. 3) is provided with the electric double layer capacitor 44 (FIG. 4) as a power storage means so that the display can be viewed for a certain time in accordance with the operation of the switch. Regardless of whether or not the solar cell generates electric power, it is possible to check the accumulated electric energy, the total accumulated electric energy, and the like.

Further, since the drive power from the system interconnection inverter 3 (FIG. 1) is no longer supplied, the display and control of the display unit 4 (FIG. 1) are controlled to the power saving mode, so that the efficiency is improved. Power consumption can be suppressed. Further, by controlling based on the timing information, it is possible to efficiently control the power saving state while suppressing unnecessary mode changes.

As described above, by displaying the solar cell as power supply power in the daytime and displaying for a certain period of time only at the time of operation by the user in the nighttime, power consumption can be suppressed low.

In this embodiment, the detection means for detecting the presence or absence of power generation by the solar cell array 1 and the grid interconnection inverter 3 shown in FIG. Although the method of sending the voltage to the microprocessor is used, various methods are conceivable, such as a method of comparing the measurement point with a reference voltage by a comparator or the like and sending the voltage to the microprocessor.

In this embodiment, an LED is used as an element for displaying the electric energy. However, for example, when a liquid crystal is used, power consumption can be suppressed lower than that of an LED. Therefore, the capacity of the power storage means can be reduced, and the number of times of display at night and the display time can be easily extended.

Further, in this embodiment, the system interconnection inverter 3 (FIG. 1) which is a system interconnection system has been described. However, the system interconnection inverter 3 may be employed in a system for supplying generated power of a solar cell to a load other than the system. It is possible.

[Embodiment 2] In the circuit of Embodiment 1,
With a very simple configuration, it is possible to check the amount of accumulated power at night. In a second embodiment, a circuit configuration that effectively uses the amount of power stored in the power storage unit will be described.

The configuration of the photovoltaic power generation system in this embodiment (FIG. 1), the internal configuration of the grid interconnection inverter 3 (FIG. 2), and the operation of the display unit 4 (FIGS. 6 and 7) are the same as those in the first embodiment. . For this reason, the above-described (the configuration example of the photovoltaic power generation system of the first embodiment), (the internal configuration example of the grid interconnection inverter 3 of the first embodiment), and (the operation example of the display unit 4).
See

This embodiment is different from the first embodiment only in the internal configuration of the display unit. FIG. 8 shows the configuration of the display unit 50 used in this embodiment.

(Example of Internal Configuration of Display Unit 50) In FIG. 8 used in the second embodiment, the flow of electric power is indicated by a solid line, and the flow of signals is indicated by a dotted line. Reference numeral 51 denotes a circuit including a power storage means for storing driving power at night, the details of which are shown in FIG. 8, the display unit 4 of the first embodiment (FIG. 3)
Only the circuit 51 is different from the above, and the other configuration is the same as (an example of the internal configuration of the display unit 4).

(Example of Configuration of Circuit 51) FIG. 9 shows an example of the configuration of the circuit 51 shown in the internal configuration diagram of the display unit 50 of FIG. The circuit 51 includes the system interconnection inverter 3 (FIG. 1)
And means for storing the voltage of the driving power supply from the inverter 3.

In FIG. 9, reference numeral 41 designates a connection cable 5, a connector 31 (FIG. 8) from the grid-connected inverter 3 (FIG. 1).
Is a drive power supply input terminal, and a drive power supply output terminal 42 outputs drive power supply to the control circuit 33 and the LED drive circuit 37 (both in FIG. 8) in the display unit. 43 is a backflow prevention diode.

Reference numerals 53 and 54 denote first and second electric double-layer capacitors as power storage means, and reference numerals 52 and 55 denote diodes. 47 is a DC / DC converter and 56 is a series / parallel switch. 58 is a switching signal input terminal of the serial / parallel switch 56 from the control circuit 33 (FIG. 8), 57 is a DC
Control circuit 3 which detects the input voltage of DC / DC converter 47
3 (FIG. 8).

The positive pole of the first electric double layer capacitor 53 is connected to the anode of the diode 52 (connected in the forward direction), and the DC / DC converter 47
, And the negative electrode is connected to the ground side of the DC / DC converter 47 to form a first power supply path.

The positive pole of the second electric double layer capacitor 54 is connected to the power supply input of the DC / DC converter 47, and the negative pole is connected to the cathode of the diode 55 (forward connection). It is connected to the ground side of the DC / DC converter 47 to form a second power supply path.

A series-parallel switch 56 is connected between the first power supply path and the second power supply path.
When the series / parallel switch 56 is ON, the electric double layer capacitors 53 and 54 are connected in series, and when OFF, they are connected in parallel. The series-parallel changeover switch 56 can be configured by a relay having a mechanical contact, but can also be configured by an electronic element such as an FET. FIG. 10 shows an example in which the series-parallel changeover switch 56 in FIG.

(Operation Example of Circuit 51) As in the first embodiment, the display unit 50 (FIG. 8) has two power modes, a normal operation mode and a power saving mode, and each mode changes according to a predetermined condition. In the daytime, when the solar cell array 1 (FIG. 1) is generating power, the electric double layer capacitors 53 and 54 are charged by the drive power from the grid interconnection inverter 3 (FIG. 1).

Whether or not the system interconnection inverter 3 (FIG. 1) supplies drive power to the display unit 4 (FIG. 1) is detected by a voltage detection circuit 45 as detection means, and is output via an output terminal 42. The judgment is made by the control circuit 33 (FIG. 8) as the control means. At this time, the control circuit 33 outputs an ON signal to the changeover switch to the terminal 58, and the electric double layer capacitors 53 and 54 are charged in a state of series connection. Although not used in FIG. 9, a circuit configuration may be adopted in which a bleeder resistor is attached in order to charge the electric double layer capacitors 53 and 54 uniformly.

At night, when it is detected that the power generation of the solar cell array 1 (FIG. 1) has ceased and the drive power supply from the grid interconnection inverter 3 (FIG. 1) has ceased to be supplied, the control circuit 33 (FIG. 8) saves. Move to power mode. Then, the stored power of the electric double layer capacitors 53 and 54 is used.

The input voltage of the DC / DC converter 47 is output to a terminal 57.

The system interconnection inverter 3 in this embodiment
The drive power supply from (FIG. 1) is 15V, and the drive power supply for the microprocessor in the control circuit 33 (FIG. 8) is 5V.
The input voltage range of the DC / DC converter 47 used in this embodiment is 5.5 V or more. DC / DC
The converter 47 has a characteristic that the amount of heat generation increases, such as a large step-down voltage value, and the conversion efficiency deteriorates. This tendency is particularly noticeable when the DC / DC converter 47 is configured by a drawbar type regulator (series regulator).

With such a configuration, the operation in FIG. 9 is as follows. Daytime, electric double layer capacitors 53, 54
Reduces the step-down voltage of the diode 43 by 0.8 V to 14.2
V is charged in the series circuit of the electric double layer capacitors 53 and 54, and each is charged at 7.1V (maximum charge state).

At night, when the control circuit (FIG. 8) detects that the supply of the drive power from the grid interconnection inverter 3 (FIG. 1) has been interrupted by the input from the terminal 46, the series-parallel switch 56 is switched by the terminal 58. Is output and DC /
The DC converter 47 includes electric double layer capacitors 53 and 5
4 in parallel. Electric double layer capacitors 53, 54
Is in the maximum charged state of 7.1 V, the diode 5
Reduce the voltage drop of 2,55 by 0.8V and 6.3V is DC
/ DC converter 47. This supply voltage is
The information is grasped by the control circuit 33 through the terminal 57. Due to the power consumption of the display unit 50 (FIG. 8), the discharge of the electric double layer capacitors 53 and 54 proceeds, and the detection voltage of the terminal 57 becomes D.
It is assumed that the input voltage of the C / DC converter drops to 5.5V. At this time, the control power supply 33 issues an ON command to the terminal 58 to turn on the series / parallel changeover switch 56, and connects the electric double layer capacitors 53 and 54 in series.

By operating as described above, DC /
By increasing the conversion efficiency by reducing the step-down voltage value in the DC converter 47, the electric double layer capacitor 5
The system is configured to effectively utilize 3,54 stored power.

FIG. 11 shows a graph of the input voltage and time of the DC / DC converter when the series-parallel switching circuit (FIGS. 9 and 10) of this embodiment is employed. 'Is 2 in the present embodiment.
When two storage means (electric double layer capacitors) are supplied to a DC / DC converter using a series-parallel switching circuit,
'DC / DC by simply connecting two storage means in series
When supplied to a converter, 'is a graph when two power storage means are simply connected in parallel and supplied to a DC / DC converter.

In the case of ', the discharge is initially started in the display state from the parallel connection of 6.3 V, and when the minimum input voltage of the DC / DC converter reaches 5.5 V, the discharge is performed by connecting in series. It is shown. 'Is 14.2V (because there is no diode voltage drop of 0.8V, (6.3 + 0.8) ×
2 shows a state in which the discharge is caused by the series connection of 2V). '
Is 7.1V (6.
(3 + 0.8 V) is shown in FIG. At this time, when the duration of the series connection is set to 100, and when the series-parallel switching circuit of
The 0, 'parallel connection was about 55 durations.

As can be seen from this graph, when the series-parallel switching circuit is employed, the driving time of the display unit can be extended even if the storage means having the same capacity is used.

In the present embodiment, an example is shown in which the number of capacitors used by switching between series and parallel is two, and the first and second power supply paths are provided. However, the number of capacitors is increased to three or four, and the first and second power supply paths, the third power supply path, and the fourth power supply path are provided by a plurality of series-parallel switching means and a plurality of diodes. Is also possible.

FIG. 12 shows an example of a circuit having four capacitors and four power supply paths. 12, the same elements as those in FIGS. 9 and 10 are denoted by the same reference numerals as in FIGS. 9 and 10.

[Embodiment 3] In Embodiment 3, a further configuration for effectively using the stored power will be described. In the present embodiment, the above-described object is achieved by separately storing the drive power for the control circuit and the drive power for the LED display.

The configuration of the photovoltaic power generation system in this embodiment (FIG. 1), the internal configuration of the grid-connected inverter (FIG. 2),
The operation of the display unit 4 (FIGS. 6 and 7) is the same as in the first embodiment. Therefore, reference is made to (the configuration example of the photovoltaic power generation system of the first embodiment), (the internal configuration example of the system interconnection inverter 3 of the first embodiment) and (the operation example of the display unit 4).

This embodiment differs from Embodiment 1 only in the internal configuration of the display unit. FIG. 13 shows the internal configuration of the display unit 60 used in this embodiment.

(Example of Internal Configuration of Display Unit 60) In FIG. 13, the flow of electric power is indicated by a solid line, and the flow of signals is indicated by a dotted line. Reference numeral 61 denotes a circuit including a power storage means for storing driving power during the night, and its configuration is shown in FIG. 13, only the circuit 61 is different from the display unit 4 of the first embodiment (FIG. 3), and the other configuration is the same as (internal configuration example of the display unit 4).

FIG. 14 shows a control circuit 33 used in FIG.
FIG. 2 is a circuit diagram showing an example of a configuration of a microprocessor and an LED display in the apparatus. 62 is a microprocessor in the control power supply 33; 63 is a drive power supply for the microprocessor;
Reference numeral 4 denotes an LED driving power supply. 72 is an LED driving element,
73 is an LED, and 65 is a current limiting resistor for LED current.

In the first embodiment, the driving power supply 63 for the microprocessor and the driving power supply 64 for the LED
Was used. At this time, if the current supply specification of the LED 73 is 20 mA, the power consumption is 100 mW.

On the other hand, when the LED drive power supply 64 is provided separately from the microprocessor drive power supply 63 and is set to 3 V, the power consumption is 60 mW, and power saving can be achieved.

Therefore, in the circuit 61 of the present embodiment, the microprocessor drive power supply 63 and the LED drive power supply 64 are separately provided, and a storage capacitor is provided in each of them.

(Example of Configuration of Circuit 61) FIG. 15 shows an example of the configuration of the circuit 61 shown in FIG. 66 and 67 are backflow prevention diodes, storage capacitors, and DC / D
This is a circuit having a C converter and the like. The circuit 66 is a control power supply circuit, and the DC / DC converter in the circuit 66 uses a 5V output. The circuit 67 is a power supply circuit for driving the LED, and the DC / DC converter in the circuit 67 uses a 3V output. Reference numeral 68 denotes an output terminal for control power supply power, and reference numeral 69 denotes an output terminal for LED drive power supply power.

(Operation Example of Circuit 61) As in the first embodiment, the display unit 60 (FIG. 13) has two power modes, a normal operation mode and a power saving mode, and the mode changes according to predetermined conditions. In the daytime, when the solar cell array 1 (FIG. 1) is generating power, the two electric double layer capacitors 91 and 92 in FIG. 15 are charged by the drive power from the grid interconnection inverter 3 (FIG. 1). .

At night, when it is detected that the solar cell array 1 has stopped generating power and the drive power from the grid interconnection inverter 3 is no longer supplied, the control circuit 33 (FIG. 13) shifts to the power saving mode. Then, the control circuit 33 suppresses the use of the stored power of the two electric double layer capacitors 91 and 92 in FIG.

When detecting that the night display switch 34 (FIG. 13) is pressed, the control circuit 33 (FIG. 13) switches to the normal mode for a certain period of time using the stored power of the two electric double layer capacitors 91 and 92. . Then, it is possible to confirm the integrated power amount, the total integrated power amount, and the like.

Further, as shown in FIG. 16, if the detection terminals 70 and 71 are provided so as to detect the stored power of the electric double layer capacitors 91 and 92, the microprocessor can be changed to the sleep mode in the power saving mode. And various applications such as changing the LED lighting duty.

As described above, in FIG. 15, the control power supply circuit 66 and the display LED drive power supply circuit 67 are separately provided at different voltages. Then, the LED 73 (FIG. 14)
Thus, the power consumption of the power storage means is effectively utilized by suppressing the power consumption of the power storage device.

In the case of this embodiment, the LED 73 (FIG. 1)
The power supply to 4) was changed from 5V to 3V. Therefore, L
When the energization current specifications of the ED 73 are equal, the LED 73
Power consumption can be reduced to 60%.

[0097]

According to the present invention, in a solar power generation system in which the control power supply of the grid-connected inverter operates during daytime when the solar cell array is generating power, the present invention can be implemented even when the solar cell array is not generating power. When necessary, the amount of power generation can be checked.

As in the first embodiment, if an electric double layer capacitor is used for the power storage means, it is possible to check the amount of power generated at night without replacing the power storage means.

Further, as in the second embodiment, the continuity control of the series / parallel switching is performed by the series / parallel switching means according to the detection voltage detected by the detection means on the first power supply path and the second power supply path. With this configuration, it is possible to efficiently use the stored power of the power storage means. As a result, the capacity of the power storage means can be reduced, and the display time of the power generation amount at night can be lengthened.

Also, as in Embodiment 3, the power consumption of the display element can be reduced by separately providing a power storage means for the display element. As a result, the capacity of the power storage means can be reduced, and the display unit can display for a longer time, such as the amount of generated power at night.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a solar power generation system used in one embodiment of the present invention.

FIG. 2 is an internal configuration diagram of a system interconnection inverter 3 used in FIG.

FIG. 3 shows a display unit 4 according to the first embodiment used in FIG.
FIG.

4 is a diagram showing an example of the configuration of a circuit 32 shown in the schematic internal configuration diagram of the display unit 4 in FIG.

FIG. 5 is an external view of a display unit 4 used in FIG.

FIG. 6 is a state transition diagram showing a normal operation of the display unit 4 used in FIG.

FIG. 7 is a state transition diagram showing an example of transition of a power mode of the display unit 4 used in FIG.

FIG. 8 is an internal configuration diagram of a display unit 50 used in a second embodiment.

FIG. 9 is a diagram illustrating an example of a configuration of a circuit 51 illustrated in a schematic configuration diagram of a display unit 50.

FIG. 10 is a diagram showing an example in which the changeover switch 56 in FIG.
9 is a diagram showing an example of a circuit constituted by No. 9;

FIG. 11 is a diagram illustrating a graph of input voltage and time of a DC / DC converter when the series-parallel switching circuit according to the second embodiment is employed.

FIG. 12 is a diagram showing an example of a circuit having four capacitors and four power supply paths.

FIG. 13 is an internal configuration diagram of a display unit 60 used in a third embodiment.

FIG. 14 is a circuit diagram showing an example of a configuration of a microprocessor and an LED display in a control circuit 33 used in FIG.

FIG. 15 is a diagram showing an example of a configuration of a circuit 61 used in FIG.

FIG. 16 is a configuration diagram in which stored power of two electric double layer capacitors can be detected by two detection terminals.

[Explanation of symbols]

1: solar cell array, 2: current collection box, 3: grid-connected inverter, 4: display unit, 5: connection cable, 6: AC distribution board, 7: AC system, 8: display means, 9: input means ,
11: input terminal, 12: input side noise filter, 13:
Orthogonal transformation circuit, 14: interconnection switch, 15: output side noise filter, 16: output terminal, 17: AC voltage detector, 1
8: AC current detector, 19: control circuit, 20: output connector, 21: DC / DC converter, 31: input connector, 32: circuit (of the first embodiment including power storage means for storing drive power), 33 : Control circuit, 34: night display switch, 35: power mode changeover switch, 36: clear switch, 37: drive circuit for driving display LED, 38:
LED for display, 41: power input terminal, 42: power output terminal, 43: backflow prevention diode, 44: electric double layer capacitor, 45: input voltage detection circuit, 46: output terminal for extracting detection voltage, 47: DC / DC converter,: State transition direction when power supply from grid-connected inverter is detected not continuing for t1 or more,: State when power supply from grid-connected inverter is detected or night display switch ON is detected Transition direction, 50:
Display unit, 51: circuit (of Embodiment 2 including power storage means for storing drive power), 52, 55: diode, 5
3, 54: an electric double layer capacitor, 56: a serial / parallel changeover switch, 57: an output signal terminal (which detects an input voltage of the DC / DC converter and sends a signal to the control circuit 33);
58: Switching signal input terminal (to the series / parallel switch 56 from the control circuit 33), 59: FET, ': Discharge of two storage units is started from a parallel connection using a series / parallel switch. A curve obtained by connecting two storage means in series and discharging was performed. ': A curve obtained by simply connecting two storage means in series and': A discharge was performed by simply connecting two storage means in parallel. Curve, 60: display unit, 6
1: (Embodiment 3 including power storage means for storing drive power)
Circuit), 62: microprocessor, 63: drive power supply for microprocessor, 64: drive power supply for LED, 6
5: current limiting resistor, 66: control power supply circuit, 67: LE
D drive power supply circuit, 68: control power supply power output terminal, 6
9: LED power supply power output terminal, 70, 71: detection terminal for detecting the stored power of the electric double layer capacitor, 7
2: LED drive element, 73: LED, 81, 82: electric double layer capacitor.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Naoki Manabe 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term (reference) in Canon Inc. 5G066 HA13 HB06 JA07 JB04 5H420 CC03 DD03 EB26 EB39 FF05 FF10 FF29 LL10

Claims (7)

[Claims] 1. A solar cell array, a power control device for controlling electric power photoelectrically converted by the solar cell array,
In a photovoltaic power generation system having a display unit having a display unit and a control circuit for displaying a power generation amount of the solar cell array from the power control device, the display unit displays a power generation amount of the solar cell array from the power control device. Input means for indicating a display type to be shown;
The photovoltaic power generation system, wherein the display unit includes a detection unit that detects the presence or absence of power generation by the solar cell array, and a power storage unit that stores power required to drive the display unit. 2. The solar cell array generates a power mode of electric power required to use the display unit based on an input from the input unit or based on a detection signal from the detection unit. Normal operation mode,
2. The solar power generation system according to claim 1, further comprising a switching unit configured to switch to a power saving mode when the solar cell array is not generating power. 3. 3. The power storage means comprises first and second power storage means for storing power, and comprises the first power storage means and a diode connected in a forward direction to a negative pole of the first power storage means. A first power supply path, and a second power supply path including a diode connected in a forward direction to the second power storage means and a positive pole of the second power storage means; A serial / parallel switching unit that is arranged between power supply paths and that switches the first power storage unit and the second power storage unit in series or in parallel; And / or control means for controlling the output of the second power supply path, wherein the serial / parallel switching means and / or the control means are driven in accordance with a detection signal from the detection means. Item 1 or 2 Sunlight power generation system. 4. The power storage means includes three or more power storage means for storing power, and three or more power storage means including three or more power storage means and diodes connected in a forward direction to the three or more power storage means. Wherein the serial / parallel switching means is respectively arranged between the three or more power supply paths, and controls the output of the power supply path in part or all of the three or more power supply paths. The photovoltaic power generation according to any one of claims 1 to 3, further comprising a control unit that drives the series / parallel switching unit and / or the control unit in accordance with a detection signal from the detection unit. system. 5. The power storage unit includes: a first power storage unit for driving the control circuit in the display unit; and a second power storage unit for driving a display element in the display unit. The solar power generation system according to claim 1, further comprising a power storage unit, wherein a storage voltage of the first power storage unit is different from a storage voltage of the second power storage unit. 6. The photovoltaic power generation system according to claim 1, wherein said power storage means is an electric double layer capacitor. 7. A photovoltaic power generation system, comprising: a calculating means for performing a calculation for displaying the display type on the display means; a storing means for storing the display type calculated by the calculating means in a memory; The display type includes a power generation amount, an integrated power amount, and a total integrated power amount, and the display of the display type on the display unit is switched by the input unit. The photovoltaic power generation system according to claim 1.