JP3241822B2 - Safety device for solar cell module - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device for a solar cell module, and is useful, for example, in connection work.

[0002]

2. Description of the Related Art When a solar cell module is installed, electrical wiring is always required. Since solar cells generate electricity when light enters from the surface, after fixing the solar cell module,
Power is always generated during wiring work. At present, there is no safety measure against electric shock in commercially available solar cell modules.

[0003] Therefore, if you touch the electrode part by mistake,
There is a risk of electric shock. Therefore, be careful not to get an electric shock during the connection work, or use insulating gloves. Alternatively, the entire solar cell array may be covered with sunlight shielding means to prevent power generation.

[0004]

The use of insulating gloves has a problem that workability is significantly reduced.

[0005] When the solar cell is covered with sunlight shielding means,
It is necessary to shield all the solar cell arrays, and light passing through the sheet and light enters even from the seam, and even if a little light enters, a voltage is generated, and it is difficult to prevent electric shock by completely shielding the light. .

[0006] Therefore, even if the electrode portion is accidentally touched during wiring work, there is no electric shock, and after the installation and wiring work is completed, it is possible to safely and easily move to a power-generating state without restriction of the work space, and impair the appearance. There has been a demand for a method capable of generating electricity without power loss.

[0007]

In the present invention, the solar cell module is provided with means for short-circuiting the output of the solar cell and means for canceling the output.

[0008]

During the wiring work, there is no danger of electric shock because the solar cell output is short-circuited. After the wiring work is completed, the short-circuit state is released, so that normal power generation can be performed without power loss.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Various methods of short-circuiting the output of a solar cell, such as a mechanical switch and a semiconductor switch, can be considered. However, since the solar cell module is installed outdoors, it is necessary to drive the switch while maintaining the waterproof and insulating properties of the solar cell output.

When a switch is driven by a mechanical operation, a movable part is required. If the movable part is not completely insulated and waterproof, moisture may enter from the movable part and cause a failure. The life of the solar cell module is said to be 20 years or more, and it is difficult to maintain the waterproofness of the movable part until the end of the life.

In addition, arranging some components on the surface of the solar cell module lowers the mounting density of the solar cells, and also degrades the appearance.

If any protrusions appear on the side surface of the solar cell module, the mounting density of the solar cell module is reduced.

When the operation on the back side of the solar cell module is required, the operation cannot be performed if there is no working space on the back side.

When providing a short circuit means in a solar cell module, it is necessary to solve the above problems.

The circuit shown in FIG. 1 is a first embodiment of the present invention. In this embodiment, a normally-off reed relay 3 which is opened and closed by magnetic force is used for insulation and waterproofing, and energy for driving the transistor 2 which is a short-circuit means by a semiconductor element is unnecessary when wiring is performed. Use the output of the battery. Since the material constituting the solar cell module is a non-magnetic material, it easily transmits magnetic force. Therefore, the reed relay 3 of the solar cell module 7 can be driven by an external magnetic field. Insulation and waterproofing are exactly the same as in the prior art, and do not affect the life.

First, a magnetic field is applied to the reed relay 3 from the outside of the solar cell module 7 by using a magnet 8, and the reed relay 3 is turned on. The reed relay 3 is connected to the base of the transistor 2 and the + side of the solar cell 1, the collector and the emitter of the transistor 2 are connected in parallel with the solar cell 1,
Further, a bypass diode 4 is connected in parallel with this. Reference numerals 10 and 11 are output terminals.

First, the transistor 2 is off.
When light enters the solar cell module, it generates electricity. Since the base of the transistor 2 has the same potential as the solar cell output by the reed relay 3, the base current flows, the transistor 2 is turned on, and the solar cell output is short-circuited.

Therefore, even if the solar cell output is erroneously contacted during the generating operation, an electric shock accident does not occur.

After completion of the connection work, by removing the magnet 8, the reed relay 3 is turned off and the base current of the transistor 2 is cut off, so that the transistor 2 is turned off and normal power generation becomes possible.

The magnetic field can be easily applied by bringing or sticking a permanent magnet to the front or back surface of the solar cell. At this time, if one of the solar cells 1 is covered by the permanent magnet from the front side, the output of the solar cell is reduced, the current flowing through the transistor 2 is reduced, and the heat generation is reduced. Transistors can be used.

In this embodiment, since a short circuit can be caused again by applying a magnetic field, wiring work can be performed without fear of electric shock even in the case of replacement work in the event of a solar cell failure.

The circuit shown in FIG. 2 is a second embodiment of the present invention. In this case, since only the fuse 5 is inserted in parallel with the solar cell 1 inside the solar cell module 7, there is no problem in waterproofness and insulation of the solar cell module. Initially, the solar cell module is short-circuited inside, so that the solar cell output does not flow to the outside and is safe.

After completion of the wiring of the solar cell, as shown in FIG. 2, the positive terminal of the external power supply 6 for disconnecting the fuse is connected to the positive output terminal 10 of the solar cell, and the positive terminal of the external power supply 6 is connected to the negative output terminal 11 of the solar cell. When the terminal is connected, a fuse cut-off current flows through the fuse 5, and the fuse 5 is blown.
Normal power generation becomes possible. Since it is electrically cut off, it can be cut off from indoor terminal boards and the like, and work on rooftops and other high places is not required.

When a plurality of solar cell modules are connected in series, after the fuse 5 of one solar cell module is turned off, the current flowing through that module may flow through the bypass diode 4 to the next solar cell module. Therefore, all the fuses 5 can be turned off.

In this case, the use of the bypass diode, the fuse and the external power supply must be in the following range.

Solar cell rated short-circuit current <fuse breaking current <external power supply current <bypass diode maximum rated current, and (number of solar cells in series × bypass diode voltage) <
External power supply voltage and (fuse cutoff current (A) × fuse resistance (Ω)) <bypass diode breakdown voltage (V). The fuse cutoff current is not the rated current of the fuse but the current that is actually turned off. It is.

FIG. 3 shows a third embodiment. The electrical wiring inside the solar cell module 7 is the same as that in FIG. 2 and there is no problem relating to insulation and waterproofing, since only a part of the surface of the solar cell 1 is provided with a means for shielding sunlight temporarily. . Since the output of the solar cell is used for breaking the fuse, no external power supply is required.

It is well known that in a solar cell module, the output current of the entire solar cell module decreases when the power generation current of at least one solar cell decreases.
Therefore, first, the surface of some of the solar cells is shielded from light by the light-shielding means 9 which can be freely opened and closed. The slightly generated solar cell output current flows to the fuse 5, and there is no danger of causing an electric shock accident. Therefore, simple light shielding means is sufficient.

After the wiring work is completed, if the light shielding means 9 is removed,
Solar cells begin normal power generation. When the output current of the solar cell exceeds the rated current of fuse 5, fuse 5 is cut off.

By partially covering one or more solar cells with the light shielding means 9, the output potential can be easily reduced to several% of the rated output.
It is possible to drop. The reason why the value does not become 0% at this time is that light is sneak from the surroundings and power is thus generated.

The fuse 5 used in the circuit of FIG. 2 completely satisfies the conditions that it must endure the rated current of the solar cell as described above and must be able to reliably shut off the bypass diode 4 with a current that does not destroy it. There is a need.

Since the generated current of the solar cell at the time of shielding sunlight can be easily reduced to 10% or less of the rating, when the light shielding means 9 is used as shown in FIG. It may be as small as 10% or less compared to the case. Therefore, if the light shielding means 9 is removed after the wiring work, the solar cell can output a current of 50% or more of the rated value in fine weather, so that a current several times or more than the rated value flows through the fuse 5 and can be cut off easily.

[0033]

According to the present invention, during the wiring work of the solar cell module, the output of the solar cell does not flow to the outside by short-circuiting the output using a semiconductor element that can be opened and closed by magnetic force. With this configuration, it is possible to prevent a wiring worker from accidentally causing an electric shock accident, and to exert a great effect on the safety of wiring work. Also, apply a magnetic field
To release the short circuit once and perform normal power generation.
The output can be short-circuited again after
Even when replacing work in the event of a malfunction,
Line work can be performed. Furthermore, the end of wiring work
Later, indoor electrical terminals
Normal power generation is started from the subboard, etc.
You can start. Also, some solar cells are shielded from light and wiring
Operation, the short-circuit current is suppressed and the fuse is reduced.
can do.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a first embodiment of the present invention.

FIG. 2 is a wiring diagram according to a second embodiment of the present invention.

FIG. 3 is a plan view of a third embodiment of the present invention.

[Description of Signs] 1 solar cell 2 transistor 3 reed relay 4 bypass diode 5 fuse 6 external power supply 7 solar cell module 9 light blocking means

Claims (7)

(57) [Claims] A short-circuiting means for short-circuiting an output; and a releasing means for releasing the short-circuit , wherein the short-circuiting means has a semiconductor element, and the releasing means is opened and closed by a magnetic force, and Turn the semiconductor element off
A safety device for a solar cell module, comprising: a relay for turning off the solar cell module. 2. Short-circuit means for short-circuiting an output, and short- circuit control means for controlling the short-circuit, wherein the short-circuit means includes a semiconductor element connected between the outputs.
Have the short-circuit control unit, the semiconductor device is opened and closed by magnetic force
Safety device for solar cell modules that further comprising a relay for controlling the ON and OFF. 3. A method for short-circuiting the output of a solar cell module.
And a short-circuit means for disconnecting the fuse by an external power supply.
Safety device for solar cell modules that comprising the element. 4. The fuse according to claim 1, wherein said fuse element has a breaking current.
The safety device for a solar cell module according to claim 3, wherein the safety output module is larger than a rated output current of the solar cell module. 5. The external power source is connected to the fuse element.
Then, the polarity is opposite to the output of the solar cell module.
4. The solar cell according to claim 3, wherein a voltage is applied.
Pond module safety device. 6. A method for short-circuiting the output of a solar cell module.
Shorting means for releasing the short circuit, and openable and closable light shielding provided on the surface of some of the solar cells
Means, wherein the short-circuit means comprises a fuse element coupled between the outputs.
Safety device for a solar cell module, characterized by comprising:
Place. 7. A method for short-circuiting the output of a solar cell module.
Open / closed light shield provided on the surface of some solar cells
Means and the short circuit means are coupled between the outputs.
The ratio of smaller rated current than the rated output current of the pond module
Solar cell module characterized by including a fuse element
Safety equipment.