JP2002339591A - Snow-melting device for solar cell attached roof and snow-melting controlling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a snow-melting device for a solar cell attached roof capable of promoting snow-melting efficiency and power generating efficiency. SOLUTION: The snow-melting device 20 includes an invertor 14 applying a predetermined voltage to a solar cell panel 11, a current detecting section 22 for detecting a current value flowing to the solar cell panel 11 in the case the predetermined voltage is applied to the solar cell panel 11 and a power source control section 23 for stopping the applied voltage from a power source section 21 when the current value detected by the current detecting section 22 becomes a set point set in advance. A state of fallen snow on the solar cell panel 11 can be decided by the current value flowing to the solar call panel 11, and when the fallen snow on the solar cell panel 11 is melted away, the applied voltage to the solar cell panel 11 can be automatically stopped. For that purpose, though there is no snow on the solar cell attached roof, the solar cell panel 11 is not heated, and the snow-melting efficiency and the power generating efficiency can be promoted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a snow melting apparatus and a snow melting control method for a roof with solar cells in which a plurality of solar cell panels for receiving sunlight and converting it into electric power are arranged vertically and horizontally on a roof surface. .

[0002]

BACKGROUND ART Conventionally, solar energy has been known as clean energy which does not adversely affect the environment and ecosystem. In using solar energy, a solar cell that converts sunlight into electricity is used. In order to make such a solar cell usable at home, a roof with a solar cell in which a solar cell is installed on a roof surface is known. Solar cells installed on roofs with solar cells need to prevent accidents such as electrical leakage and short circuits due to water.Solar cells, which are solar cells, are housed inside a flat, completely waterproof case, and solar cell panels It is installed as. This solar cell panel has a predetermined number of solar cells so that a predetermined voltage and power can be obtained by one sheet (see Japanese Patent Application Laid-Open No. H10-140770).

Here, when snow falls in a snowfall zone or the like and the snow piles up on the roof with solar cells, the solar cell panels cannot receive the light of the sun and cannot generate electricity. This state continues until the snow on the solar cell roof melts even if the snow stops. For this reason, a sprinkler or an electric heating sheet is installed on the roof surface to forcibly melt snow accumulated on the roof with solar cells. However, installing a sprinkler or electric heating sheet on the roof surface reduces the number of solar panels installed by that amount and reduces the power generation efficiency of the roof with solar cells. A technique has been developed in which the applied solar cell panel generates heat to melt snow accumulated on a roof with solar cells.

[0004]

However, while the solar cell panel is generating heat and melting the snow accumulated on the roof with solar cells, power cannot be generated, and in particular, power is applied to the solar cell panel. Since the operation of stopping the voltage is performed manually, the solar cell panel may generate heat even though the roof with the solar cell does not already have snow, and there is a problem that the snow melting efficiency and the power generation efficiency are poor.

An object of the present invention is to provide a snow melting apparatus for a roof with a solar cell and a snow melting control method capable of improving snow melting efficiency and power generation efficiency.

[0006]

The present invention will be described with reference to the accompanying drawings. Referring to the drawings, a plurality of solar cell panels 11 for receiving sunlight and converting it into electric power are provided on a roof surface 2A. A power supply unit (for example, an inverter 14) that applies a predetermined voltage to the solar cell panel 11, which is a snow melting device 20 of the roof 2, and a solar cell panel 11 when a predetermined voltage is applied to the solar cell panel 11. A current detecting unit 22 for detecting a flowing current value; and, when the current value detected by the current detecting unit 22 becomes a preset current value,
A power supply control unit that stops application of a voltage by the power supply unit. Here, as the power supply unit, for example, an inverter that converts DC power generated by the solar cell panel into AC power and outputs the AC power,
Any bi-directional inverter that can convert AC power to DC power and output the DC power may employ this bi-directional inverter, or may be dedicated to configuring a snow melting device separately from this inverter. A thing may be adopted. Further, when a predetermined voltage is applied, the value of the current flowing through the solar cell panel is such that the surface temperature is around 0 ° C. (specifically, −5 ° C.
The temperature is preferably + 5 ° C, more preferably -3 ° C to + 3 ° C, and even more preferably -2 ° C to + 2 ° C. ) Is preferably a value obtained from the voltage-current characteristics of the solar cell panel. The set current value is such that the surface temperature of the solar cell panel is close to 0 ° C. (specifically, −5 ° C. to + 5 ° C.).
C is preferable, more preferably -3C to + 3C, and still more preferably -2C to + 2C. ) Can be adopted as the value of the current flowing when the temperature is out of the range.

[0007] That is, the internal resistance of the solar cell panel changes according to the temperature. If the voltage is constant, the current flowing through the solar cell panel changes according to the temperature. Utilizing this characteristic, when a predetermined voltage is applied, if the current value is a value obtained from the voltage-current characteristic of the solar cell panel whose surface temperature is close to 0 ° C., snow is accumulated on the solar cell panel. Is determined to be
Snow melting operation is continued. On the other hand, when a predetermined voltage is applied, if the current value is a set current value that flows when the surface temperature of the solar cell panel becomes a temperature outside the vicinity of 0 ° C.,
It is determined that the surface temperature is not close to 0 ° C., in other words, that there is no snow on the solar cell panel,
Snow melting operation stops.

According to the present invention, it is possible to determine the snow condition on the solar cell panel based on the value of the current flowing through the solar cell panel, and when the snow accumulated on the solar cell panel disappears, it is automatically determined. Since the application of voltage to the solar cell panel can be stopped, the solar cell panel does not generate heat even though there is no snow on the roof with solar cells. Efficiency can be improved.

In the above, the above-described snow melting apparatus 20 is capable of performing power generation control for bringing the solar cell panel 11 into a power generation state, and the power supply control unit 23 operates after the power supply unit stops applying voltage. It is desirable to switch to the eleventh power generation control. With this configuration, it is possible to automatically set the solar cell panel to the power generation state after the application of the voltage to the solar cell panel is stopped. Can be almost eliminated, whereby the snow melting efficiency and the power generation efficiency can be further improved.

The above-mentioned snow melting apparatus 20 has a timer 24 for switching the operation according to a set time, and the power control section 23 can automatically control the power section by the timer 24. preferable. In this way, it is possible to automatically start and end the snow melting operation of the roof with the solar cell, and to perform the power generation control, thereby performing the automatic switching operation between the snow melting operation and the power generation operation. So,
Snow melting efficiency and power generation efficiency can be further improved.

[0011] The present invention is not limited to the above-described device.
A voltage application step of applying a predetermined voltage to the solar cell panel 11, a current detection step of detecting a current flowing through the solar cell panel 11 when a predetermined voltage is applied to the solar cell panel 11, and a current detection step When the current detected in step (b) reaches a preset current value, a method for controlling snow melting of the roof with solar cell 2 including a power control step of stopping the voltage application step is also realized. Can be obtained.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a house 1 according to an embodiment of the present invention. The house 1 is built in a snowfall area, and transmits sunlight to a plurality of solar cell panels 11 (described later).
And a snow melting device 20 for melting the snow accumulated on the solar cell panel 11 for receiving power from the received sunlight.

More specifically, the photovoltaic power generator 10 includes a solar cell panel 11 in which a solar cell, which is a solar cell that generates power from sunlight, is housed in a flat waterproof case.
It converts sunlight into electricity for use. The photovoltaic power generation device 10 includes a plurality of solar panels 11 arranged on a roof surface 2A of a sloped roof 2 of a house 1, a terminal box 12 which is a connector for integrating outputs from the respective solar panels 11, and An inverter 14 converts the electricity collected by the terminal box 12 from DC to AC. Thus, the sloped roof 2 is a roof with solar cells. Therefore, the DC power converted by each solar cell panel 11 is supplied to the terminal box 12.
And output to the inverter 14. And
The DC power input to the inverter 14 is converted into AC power, and is supplied to equipment (not shown) such as lighting equipment and air conditioners in the house 1 via the distribution board 15.

The snow melting device 20 performs a snow melting operation for melting snow accumulated on the solar cell panel 11, and includes the inverter 14 as a power supply unit and the snow melting controller unit 2.
0A. That is, inverter 1
4 converts the DC power converted by each solar cell panel 11 into AC power and outputs the AC power to the distribution board 15 and the like, and converts the AC power used in the house 1 into DC power. This is a bidirectional inverter that can output to the solar cell panel 11.

The inverter 14 during the snow melting operation applies a predetermined voltage to each of the solar cell panels 11.
By applying a predetermined voltage from the inverter 14 to the solar cell panel 11, the solar cell panel 11 generates heat. Here, the solar cell panel 11
The internal resistance changes according to the temperature. If the voltage is constant, the current flowing through the solar cell panel 11 changes according to the temperature. Specifically, as shown in FIG.
° C, a voltage-current characteristic as shown by a curve A is shown. Similarly, when the surface temperature is about 5 ° C, a voltage-current characteristic is shown as a curve B. When the surface temperature is about -5 ° C, a curve C is shown. Voltage-current characteristics as shown in FIG. In the present embodiment, the predetermined voltage output from the inverter 14 is set to 30 to 35 (V) per solar cell panel.

The snow melting controller 20A includes a current detector 22, a power controller 23, and a timer 24. The current detection unit 22 detects a current value flowing through the inverter 14 when a predetermined voltage is applied from the inverter 14 to the solar cell panel 11.
The detected current values are sequentially output to the power supply control unit 23.

The power supply control unit 23 has a built-in voltage-current characteristic database obtained by converting the graph shown in FIG. 2 into a database. The voltage-current database, the current value input from the current detection unit 22, and a timer 24 described later Thus, the control of the inverter 14 and the power generation control are performed. Specifically, the power supply control unit 23
2, when a predetermined voltage is applied to the solar cell panel 11 from the inverter 14, the surface temperature becomes zero.
C. (approximately −5 ° C. to + 5 ° C., more preferably −3 ° C. to + 3 ° C., even more preferably −2 ° C.)
If the set current value (current value in the area P1 in FIG. 2) flows when the temperature is out of the range from (° C. to + 2 ° C.), it is determined that there is no snow on the solar cell panel 11 and the inverter 14
Is stopped. Then, the power control unit 23
Outputs the inverter 14 stop signal and the power generation control start signal of the solar cell panel 11 to the photovoltaic power generation device 10 after stopping the application of the voltage by the inverter 14 (not shown). In other words, the conversion and output directions of the inverter 14 are reversed, so that the inverter 14 converts the DC power converted by each solar cell panel 11 into AC power and outputs the AC power to the distribution board 15 and the like. As a result, power generation control for bringing the solar cell panel 11 into a power generation state is automatically performed.

On the other hand, the power supply control unit 23
When a predetermined voltage is applied to the solar cell panel 11 from the inverter 14 when the surface temperature is 0 ° C.
Near (specifically, -5 ° C to + 5 ° C is preferable, more preferably -3 ° C to + 3 ° C, and still more preferably -2 ° C.
To + 2 ° C.) (the region P in FIG. 2).
(Current value of 2), it is determined that snow is piled up on the solar cell panel 11, and the application of the voltage by the inverter 14 is continued.

The timer 24 switches the operation in accordance with the set time, and is connected to the power control unit 23.
In the timer 24, only the start time of the snow melting operation or the start time and the end time are set. That is, when the start time comes, the timer 24 outputs a start signal to the power supply control unit 23, and the power supply control unit 23 starts the application of the voltage by the inverter 14 based on the start signal.
On the other hand, when the end time comes, the timer 24 sets the power control unit 2
Then, the power control unit 23 stops the application of the voltage by the inverter 14 based on the end signal. When the set time of the timer 24 is only the start time, when the current value input from the current detection unit 22 to the power control unit 23 becomes the above-described set current value, the application of the voltage by the inverter 14 is stopped. Stop automatically. Here, the start time and the end time set in the timer 24 indicate that the sun rises, the snow accumulated on the solar cell panel 11 is easily melted, and the intensity of sunlight that has not yet been generated by the solar power generation device 10. It is preferable that the time zone is set to be around 7:00 to 9:00 in the morning.
In other words, it is possible to melt the snow accumulated on the solar cell panel 11 by the snow melting operation for about 2 hours in this time zone. When it is not desired to allow snow to be piled on the roof 2 due to prevention of falling snow, etc., there is a method of performing a snow melting operation every certain time. Also in this case, the snow melting operation is performed by the current detection unit 22.
It is controlled by the current value detected at.

Next, the procedure for controlling snow melting of the roof with solar cells 2 will be described with reference to the flowchart of FIG. here,
In the house 1, power is generated by the photovoltaic power generator 10 in the daytime, and snow is piled up on the solar panel 11 of the roof 2 at night. 1) First, when the set start time comes, the timer 24 outputs a start signal to the power control unit 23 (process S1). 2) When the start signal is input from the timer 24, the power control unit 23 causes the inverter 14 to start applying a voltage to the solar cell panel 11 (process S2). At the time of starting the voltage application, the current value may become the set current value. Therefore, for a certain time after the start, the control is performed so that the snow melting operation is performed even if the current value is the set current value. ing. 3) The current detector 22 detects the value of the current flowing through the solar cell panel 11 according to the voltage applied by the inverter 14 (process S3).

4) If the detected current detected by the current detector 22 is the current value in the area P1 shown in FIG. 2, that is, the set current value (step S4), the power supply controller 23 Judging that there is no snow above, the inverter 14
Is stopped (process S5), and thereafter, the inverter 14 stop signal and the power generation control start signal of the solar cell panel 11 are output to the photovoltaic power generator 10 (process S5).
6). The photovoltaic power generator 10 receives this signal and starts power generation. 5) On the other hand, the power supply control unit 23
2 is the current value of the area P2 shown in FIG. 2 (process S4), and if the end signal from the timer 24 is not input to the power control unit 23 (process S4).
7), it is determined that snow has accumulated on the solar cell panel 11, and the application of the voltage by the inverter 14 is continued;
Subsequently, the current detection unit 22 detects the current. 6) When the end signal from the timer 24 is input to the power control unit 23 (process S7), the power control unit 23 stops the application of the voltage by the inverter 14 (process S5). Then, an inverter 14 stop signal and a power generation control start signal for the solar cell panel 11 are output (process S6).
In this manner, the snow melting control of the roof with solar cells 2 is performed.

According to this embodiment, the following effects can be obtained. That is, the snow melting apparatus 20 including the inverter 14, the current detecting unit 22, and the power control unit 23
Is used, the state of snow on the solar cell panel 11 can be determined based on the value of the current flowing through the solar cell panel 11, and when the snow accumulated on the solar cell panel 11 disappears, the solar cell panel 11 is automatically It is possible to stop the application of the voltage to. For this reason, the solar cell panel 11 does not generate heat even though the roof 2 with solar cells does not already have snow, and the snow melting efficiency and the power generation efficiency can be improved.

The power supply control unit 23 includes an inverter 14
After the application of the voltage to the solar cell panel 11 is stopped, the solar cell panel 11 can be automatically set to the power generation state, so that loss such as time when switching from the snow melting state to the power generation state can be almost eliminated. Accordingly, snow melting efficiency and power generation efficiency can be further improved.

Further, since the snow melting apparatus 20 has a timer, the snow melting operation of the roof with solar cells 2 can be automatically started and ended, and the snow melting operation can be performed by controlling the power generation. Automatic switching operation of the power generation operation can be performed. Thereby, snow melting efficiency and power generation efficiency can be further improved.

Further, since the inverter 14 of the photovoltaic power generator 10 is used as the power supply unit of the snow melting device 20, when the snow melting device 20 is installed in the house, only the snow melting controller 20A needs to be installed. ,
Installation work of the snow melting device can be easily performed.

It should be noted that the present invention is not limited to the above-described embodiment, but includes other configurations that can achieve the object of the present invention, and also includes the following modifications and the like.
For example, in the above-described embodiment, the snow melting apparatus is provided with the timer. However, the present invention is not limited to this. For example, the snow melting operation may be omitted if the operator manually starts and ends the snow melting operation.

In the above-described embodiment, the snow melting device can control the power generation of the solar power generation device.
The present invention is not limited to this. For example, if the operator manually controls the power generation of the photovoltaic power generation device after the snow melting operation is completed, the snow melting device may not have the function.

Further, in the above-described embodiment, the stop of the application of the voltage by the inverter is determined from the voltage-current characteristics shown in FIG. 2. However, the present invention is not limited to this. For example, it is determined from other characteristics such as temperature characteristics. And it may be appropriately selected in implementation.

Further, the predetermined voltage by the inverter is not limited to the numerical value described in the above-described embodiment, but may be appropriately determined in the implementation.

Further, in the above-described embodiment, the inverter of the photovoltaic power generator is used as the power supply unit of the snow melting apparatus. However, the present invention is not limited to this. For example, as shown in FIG. The power supply unit 21 may be separately prepared. In this way, it can be attached to an existing house having a normal solar power generation device, and the range of use of the snow melting device can be expanded.

[0031]

As described above, according to the snow melting apparatus for a roof with a solar cell and the snow melting control method of the present invention, the following effects can be obtained. That is, according to the snow melting apparatus and the snow melting control method for a roof with a solar cell according to the first, second, fifth, and sixth aspects, it is possible to determine the snow accumulation state on the solar cell panel based on the current value flowing through the solar cell panel. When the snow accumulated on the solar panel disappears, the application of voltage to the solar panel can be automatically stopped. Without causing fever,
Snow melting efficiency and power generation efficiency can be improved.

Further, according to the snow melting apparatus and the snow melting control method for a roof with a solar cell according to the third and seventh aspects, after the application of the voltage to the solar cell panel is stopped, the solar cell panel is automatically turned into a power generation state. Therefore, it is possible to substantially eliminate loss such as time when switching from the snow melting state to the power generation state, and thereby further improve the snow melting efficiency and the power generation efficiency.

Further, according to the snow melting apparatus and the snow melting control method for a roof with a solar cell according to the fourth and eighth aspects, the snow melting operation of the roof with a solar cell can be automatically started and terminated, and the power generation can be performed. By performing the control, the automatic switching operation between the snow melting operation and the power generation operation can be performed, so that the snow melting efficiency and the power generation efficiency can be further improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a house according to an embodiment of the present invention.

FIG. 2 is a diagram showing voltage-current characteristics of the solar cell panel in the embodiment.

FIG. 3 is a flowchart showing a procedure of a snow melting operation in the embodiment.

FIG. 4 is a modification of the present invention, and is a schematic configuration diagram showing a house.

[Explanation of symbols]

 2 Roof 2A Roof surface 11 Solar panel 20 Snow melting device 21 Power supply unit 22 Current detection unit 23 Power supply control unit 24 Timer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hirofumi Ida 2-4-5 Takaido Higashi, Suginami-ku, Tokyo Inside Misawa Homes Co., Ltd. (72) Inventor Masato Iijima 2-4-5 Takaido Higashi, Suginami-ku, Tokyo Misawa Home Co., Ltd. (72) Inventor Norikazu Sakai 2-45-5 Takaido Higashi, Suginami-ku, Tokyo Misawa Home Co., Ltd. (72) Inventor Hironobu Hisashi 801 Domachi Omron Co., Ltd. (72) Masao Mabuchi Inventor Masao Mabuchi 801 Shimogyo, Shimogyo-ku, Kyoto Shimogyo Horikawa Higashi-iri Minami Fudomachi Omron Co., Ltd. (72) Inventor Takashi Ito 1 Nishishinjuku, Shinjuku-ku, Tokyo 24F, S-Tech Information Building 19F, M.S.K. Co., Ltd. (72) Inventor Kengo Wakabayashi West of Shinjuku-ku, Tokyo 1-24-1, Shinjuku S-Tech Information Building 19F M-S-K Co., Ltd. F-term (reference) 2E108 AA02 GG12 GG18 KK04 LL01 MM00 NN07 5F051 BA03 JA11

Claims (8)

[Claims] 1. A snow melting device for a roof with solar cells, wherein a plurality of solar cell panels for receiving sunlight and converting it into electric power are arranged vertically and horizontally on a roof surface, wherein a predetermined voltage is applied to the solar cell panels. A power supply unit, a current detection unit that detects a current value flowing through the solar cell panel when a predetermined voltage is applied to the solar cell panel, and a current value detected by the current detection unit is set in advance. A power control unit for stopping application of a voltage by the power supply unit when the current value reaches a set current value. 2. The solar cell with a solar cell according to claim 1, wherein a current value flowing through the solar cell panel when the predetermined voltage is applied has a surface temperature of about 0 ° C. A snow melting device for a roof with solar cells, wherein the value is obtained from the voltage-current characteristics of the panel. 3. The snow melting device for a roof with a solar cell according to claim 1, wherein power generation control for bringing the solar cell panel into a power generation state can be performed. After the voltage application by the power supply unit is stopped, the control is switched to the power generation control of the solar cell panel. 4. The snow melting device for a roof with a solar cell according to claim 1, further comprising a timer for switching an operation according to a set time, wherein the power control unit includes: A snow melting device for a roof with a solar cell, wherein the timer automatically controls the power supply unit. 5. A snow melting control method for a roof with solar cells, wherein a plurality of solar cell panels for receiving sunlight and converting it into electric power are arranged vertically and horizontally on a roof surface, wherein a predetermined voltage is applied to the solar cell panels. A voltage application step of applying, a current detection step of detecting a current flowing through the solar cell panel when a predetermined voltage is applied to the solar cell panel, and a current detected in the current detection step is set in advance. A power control step of stopping the voltage application step when the current value reaches a set current value. 6. The method for controlling snow melting of a roof with solar cells according to claim 5, wherein the current value flowing through the solar cell panel when the predetermined voltage is applied is a solar current whose surface temperature is set to near 0 ° C. A snow melting control method for a roof with solar cells, characterized in that the value is obtained from the voltage-current characteristics of the battery panel. 7. The method for controlling snow melting of a roof with solar cells according to claim 5 or 6, wherein the voltage applying step is performed by the power supply control step in order to perform power generation control for bringing the solar cell panel into a power generation state. A power generation control step of switching to power generation control of the solar cell panel after the stop of the operation. 8. The method for controlling snow melting of a roof with a solar cell according to claim 5, wherein the power control step is automatically performed by a timer that switches operation according to a set time. A method for controlling snow melting on a roof with solar cells, characterized in that: