WO2012077703A1 - Solar power generation system and connection box used therein - Google Patents

Abstract

A solar power generating system comprising: solar cell modules; strings connecting a plurality of said solar cell modules in series; and a connection box connecting a plurality of said strings. The connection box has connection terminals for connecting the strings, and the connection terminals are mounted at an angle.

Description

Solar power generation system and junction box used for the solar power generation system

The present invention relates to a solar power generation system and a junction box used for the solar power generation system.

In recent years, solar power generation has attracted attention as an environmentally friendly power generation that does not generate carbon dioxide. Moreover, the price of the solar cell module is also on a downward trend. For these reasons, the use of solar power generation has expanded from household power auxiliary means to large-scale industrial power generation.

In such a photovoltaic power generation system using photovoltaic power generation, regardless of the scale, a string in which a plurality of solar cell modules are connected to a connection box that combines the power of the strings, and a collection that combines power from the plurality of connection boxes. It is comprised from the power converter device which carries out the alternating current conversion of the electric power from an electrical box and a current collection box.

Since conventional solar cell power generation systems are small in scale and often installed in homes, etc., and the roof area that can be installed is limited, power converters that collect power from solar cell modules are It was installed inside (JP-A-10-201086, JP-A-2002-33502).

In addition, the connection box used in the industrial solar cell power generation system includes a connection terminal for connecting a plurality of wires connected to a plurality of strings, a switch for opening and closing an input from each terminal, and these in parallel. It has internal wiring for connection, a breaker that is a safety device, a connection terminal for wiring for connection to a power conversion device or a current collection box, etc., and the size must be increased as a whole.

When installing a solar cell module on a relatively large base in a state of tilting southward, the highest point of installation of the solar cell array, which is a unit of a plurality of solar cell modules, is a relatively high position. For this reason, a connection box may be installed in the lower part on the north side of the solar cell array mount. On the other hand, when the platform is relatively small or the tilt angle is small, the solar cell module is affected by shadows from peripheral devices such as a junction box, so these peripheral devices are located sufficiently away from the solar cell module. Had been placed.

JP-A-10-201086 JP2002-33502

However, if there is a distance between the installation location of the solar cell array and the installation location of peripheral equipment such as a junction box, the efficiency of wiring deteriorates. Therefore, when these peripheral devices are installed near the solar cell array, if the highest point of the peripheral device is higher than the highest point of the solar cell array, The power generation efficiency of the battery system is reduced.

The present invention has been made in view of the above problems, and the object thereof is to suppress the height of peripheral devices used in the solar power generation array, and the peripheral devices in the vicinity of the solar cell array regardless of the installation method of the solar cell array. Is to realize a solar power generation system in which is arranged.

The solar power generation system according to the present invention is a solar power generation system having a solar cell module, a string in which a plurality of the solar cell modules are connected in series, and a connection box to which a plurality of the strings are connected. It has a connection terminal for connecting with the said string, and this connection terminal is characterized by having an attachment angle.

The solar power generation system according to the present invention is a solar power generation system including a solar cell module, a string in which a plurality of the solar cell modules are connected in series, and a connection box to which a plurality of the strings are connected. Is characterized by having metal plate wiring connecting the power of the plurality of strings in parallel.

In this configuration, the connection box has wiring of a metal plate that connects the power of the plurality of strings in parallel, and a part of the metal plate is formed in a comb shape, and each end of the comb shape and the string The wiring may be electrically connected to the other wiring.

In the above configuration, the solar cell module is installed on the roof surface, and the wiring from the string is held at the lower part of the connection box so as not to contact the roof surface at the lower part of the connection box. The structure which has a wiring holding mechanism may be sufficient.

Furthermore, in the above-described configuration, the solar cell module is installed on a folded roof surface, the width of the connection box is narrower than the width of the peak portion of the folded plate roof, and the bottom surface of the connection box is lower than the peak portion of the roof portion. Alternatively, the configuration may be fixed at a low position.

Further, in the above configuration, with reference to the lower end of the installed solar cell module, the height of the junction box is H, the solar altitude at 9 or 15 o'clock of the winter solstice of the installation location of the solar power generation system is A, When the azimuth is B, it is preferable that the solar cell module be installed on the north side of the junction box with a distance of H × (1 / tanA) × cosB.

Alternatively, with reference to the lower end of the installed solar cell module, the height of the junction box is H, the solar altitude at 9 or 15 o'clock of the winter solstice at the installation location of the photovoltaic power generation system is A, and the azimuth is B In this case, the solar cell module may be installed on the east or west side of the junction box with a distance of H × (1 / tanA) × sinB.

Alternatively, a plurality of arrays in which a plurality of the strings are arranged in parallel are provided, and a passage is provided between the arrays, and the height of the junction box is set to H with respect to the lower end of the installed solar cell module, When the solar altitude at 9 or 15 o'clock in the winter solstice is A and the azimuth angle is B, the width in the north-south direction of the passage is H × (1 / tanA) × cosB or more. A certain configuration may be used.

Alternatively, in a solar power generation system having a solar cell module, a string in which a plurality of the solar cell modules are connected in series, and a connection box to which the strings are connected, a plurality of arrays in which the strings are arranged in parallel are provided. , A passage is provided between the arrays, the height of the junction box is set to H with respect to the lower end of the installed solar cell module, and the winter solstice of the installation place of the solar power generation system is 9 o'clock or 15 o'clock When the solar altitude is A and the azimuth angle is B, the width of the passage in the east-west direction may be H × (1 / tanA) × sinB or more.

A connection box according to the present invention is characterized in that a plurality of strings in which a plurality of solar cell modules are connected in series are connected in parallel, and a connection terminal for connecting to the string has an attachment angle. Yes.

Moreover, the connection box according to the present invention is a connection box in which a plurality of strings of solar cell modules connected in series are connected in parallel, and has wiring of a metal plate that connects the power of the strings in parallel. It is characterized.

Since the solar power generation system according to the present invention can reduce the height of the connection box for connecting the power from the solar cell string in parallel, it can be installed near the solar cell module, and the wiring efficiency can be increased. As a result, the efficiency of the entire photovoltaic power generation system is increased.

It is a perspective view showing the outline of one embodiment of the photovoltaic power generation system of the present invention. It is a perspective view of the appearance of a junction box used in one embodiment of the photovoltaic power generation system of the present invention. It is a perspective view which shows the terminal block and metal wiring of a connection box used by one Embodiment of the solar energy power generation system of this invention. The relationship of the height and installation distance of the solar cell array used in one Embodiment of the solar power generation system of this invention and a connection box is shown. The arrangement | positioning relationship of the maintenance channel | path of one embodiment of the solar energy power generation system of this invention, a solar cell array, and a connection box is shown. It is a perspective view which shows the terminal block of the connection box used with the conventional solar power generation system.

[Embodiment 1]
The photovoltaic power generation system according to the first embodiment will be described with reference to the drawings.

FIG. 1 shows an outline of an embodiment of the photovoltaic power generation system of the present invention.

This solar power generation system includes a solar cell string in which a plurality of solar cell modules are connected in series on a folded roof 102 of a building 101, a plurality of solar cell arrays 103 arranged in combination of the strings, and a solar cell string. And a connection box 105 electrically connected using a connection cable 104 for connecting the connection box and a connection cable 106 to the current collection box for electrically connecting the connection box and the current collection box (not shown). Yes. Between the solar cell arrays 103, a passage 107 is secured for a worker to pass during maintenance. In this embodiment, the solar cell array 103 is installed in parallel with the folded plate roof 102.

FIG. 2 is an enlarged view around the connection box 105. The end of the metal plate that constitutes the roof material of the folded plate roof 102 is bent and hooked, and the goblet metal fitting 110 is fixed to the gouge part that is joined, and the fixing bar 111 is hung between the goblet holding metal pieces 110. Further, the connection box 105 is installed on the fixing bar 111. In order to suppress the height of the connection box 105 from the folded-plate roof 102 as much as possible, the bottom of the connection box 105 has a space from the valley of the folded-plate roof 102 so that the bottom does not touch the valley. It has become. Since the bottom of the junction box 105 has a space between the valley of the folded-plate roof 102, rainwater flowing in the valley of the folded-plate roof 102 does not directly touch the junction box. Moreover, the bottom of the connection box 105 has a hole for taking in the connection cable 104 from the solar cell string and the connection cable 106 to the current collection box. When holes for taking in these wirings (104, 106) are provided on the side surfaces, it is necessary to seal with a sealing material so that rainwater transmitted through the wirings (104, 106) and the connection box 105 does not enter the inside. Arise.

Furthermore, a wiring guide 112 is provided at the bottom of the connection box 105. The wiring guide 112 can mount the wiring 104 connecting the solar cell string and the connection box and the connection cable 106 connecting the connection box and the current collection box on the upper surface of the wiring guide 112. Is prevented from touching the folded-plate roof 102. If the connection cable 104 and the connection cable 106 are in contact with the folded plate roof 102, dust accumulated on the roof surface may be caught by these wirings (connection cables 104, 106) and the flow of rainwater may be blocked. Then, water enters from the hole at the bottom of the junction box. Thus, the wiring guide 112 is effective as a rainwater countermeasure.

[Embodiment 2]
The photovoltaic power generation system according to the second embodiment will be described with reference to the drawings.

FIG. 6 is a perspective view showing the inside of the conventional junction box, particularly the periphery of the terminal block to which the wiring 104 from the solar cell string is connected. A terminal block 201 is attached to the side surface 202 of the connection box inside the connection box. For this reason, the terminal block 201 is attached perpendicularly to the junction box bottom 203. There is a hole 204 for taking in the wiring 104 from the solar cell string in the bottom 203 of the connection box, and the wiring 104 is taken into the inside through this hole 204.

The wiring 104 from the solar cell string is connected by arranging a high potential wiring 104a and a low potential wiring 104b from each string in pairs. A connection terminal 205 is provided at each end of the high potential wiring 104 a and the low potential wiring 104 b from each string, and the connection terminal 205 is connected to the terminal block 201 by a screw 207. The terminal block 201 is connected to a high potential wiring 206a and a low potential wiring 206b. Note that a switch is provided between the terminal block 201 and the high potential wiring 206a and the low potential wiring 206b to the inside for disconnecting the solar cell module from the inside of the connection box 105 during maintenance. Not shown.

On the other hand, FIG. 3 is a perspective view showing the inside of the connection box 105 used in the photovoltaic power generation system of the present invention, particularly the periphery of the terminal block to which the wiring 104 from the solar cell string is connected. Inside the connection box 105, a terminal block 301 having an attachment angle inclined with respect to the vertical direction with respect to the bottom surface 203 is provided. The bottom 203 of the connection box 105 has a hole 204 for taking in the wiring 104 from the solar cell string, and the wiring 104 is taken into the inside through this hole 204. Wirings 104 from the solar cell strings taken in are arranged in pairs of high potential wirings 104a and low potential wirings 104b from each string. A connection terminal 205 is provided at each end of the high potential wiring 104 a and the low potential wiring 104 b from each string, and the connection terminal 205 is connected to the terminal block 301 by a screw 207. The terminal block 301 has an inclination angle in the range of 0 to 90 degrees with respect to the vertical direction. If the inclination angle is 0 degree or close to it, the effect of reducing the height of the junction box 105 is small compared to the conventional one. When the inclination angle is 90 degrees, the thickness of the terminal block 301 is occupied with respect to the vertical direction of the terminal block 301, so that the height can be minimized. However, in order to connect the wiring 104 from the solar cell string to the hole 204 in the bottom surface 203, it is necessary to bend the wiring 104 at a right angle. If the hole 204 for taking in the wiring 104 is opened in the wall surface of the connection box 105, a means for preventing rainwater from entering is necessary, and a measure for waterproofing is a great effort. Further, when the wiring 104 is screwed to the terminal block 301, the screwing work is performed from the vertical direction, and the tool comes into contact with the internal structure, and the working efficiency is lowered. If the terminal block 301 is designed to have an appropriate inclination angle in a range larger than 0 degrees and smaller than 90 degrees, the occupation in the vertical direction is reduced, and extra time is required when attaching the connection terminal 205 to the terminal block 301. There is no need for it. Actually, the inclination angle of the terminal block 301 is designed in consideration of the occupation in the vertical direction and the efficiency of wiring connection work, depending on the size of the bottom surface 203 and the wiring and structure inside the connection box. In the present embodiment, since the operator works in a state where the operator is squatting from the upper side with respect to the junction box partially contained in the valley portion of the folded plate roof, the inclination angle of the terminal block is approximately 30 degrees or more and 60 degrees or less. If there is, workability is good.

The terminal block 301 is connected to a high potential wiring metal plate 306a and a low potential wiring metal plate 306b. Note that a switch is provided between the terminal block 301 and the high potential wiring 206a and low potential wiring 206b to the inside for disconnecting the solar cell module from the inside of the connection box 105 during maintenance. Not shown. Since the high potential wiring metal plate 305a and the low potential wiring metal plate 305b are metal plates, processing such as bending is easy. Although it is necessary to route the internal wiring inside the connection box 105, the bending radius can be made smaller than that by using a metal plate and the space can be saved.

Furthermore, the connection part with the terminal block 301 has a comb shape. The terminal block 301 has high-potential connection terminals 205 and low-potential connection terminals 205 arranged alternately. This is because the wirings 104 from a plurality of strings are connected so that the high potential wiring 104a and the low potential wiring 104b are paired in consideration of ease of later maintenance. In the present embodiment, since the connection portion is comb-shaped, the connection terminals 205 arranged alternately can be easily connected to realize further space saving.

When a backflow prevention diode is connected for each solar cell string, a backflow prevention diode may be inserted between the connection terminal 205 and the comb-shaped portion of the high potential wiring metal plate 305a or the low potential wiring metal plate 305b. In this case, since the backflow prevention diode is connected to the connection terminal 205 and the wiring metal plate 306, it is fixed more stably than being connected between the cables.

[Embodiment 3]
A photovoltaic power generation system according to a third embodiment will be described with reference to the drawings.

FIG. 4 is a diagram showing the relationship between the height and the installation distance between the junction box 105 used in the photovoltaic power generation system of the present invention and the solar cell array 103 in which a plurality of solar cell modules are collected. In the photovoltaic power generation system of the present embodiment installed on the roof surface 102, the height of the connection box 105 is higher than the height of the solar cell array 103. Accordingly, when the solar cell array 103 and the connection box 105 are installed adjacent to each other, the connection box 105 is shaded on the solar cell array 103. In a large-scale photovoltaic power generation system, the solar cell array is installed parallel to the installation surface such as the roof 102 in consideration of wind pressure or at an angle toward the south in order to receive sunlight more efficiently. The By appropriately designing the relationship between the distance between the connection box 105 and the solar cell array 103 and the height of the connection box 105 from the lower end of the light receiving surface of the solar cell array 103, power generation by the shadows of the devices constituting the solar power generation system It is possible to construct an efficient system without reducing the amount of space and reducing the installation area to prevent the influence of shadows.

In general, regarding the installation of solar cell modules, it is said that there will be no effect on the annual power generation unless it becomes a shadow during the winter solstice from 9:00 to 15:00. Here, if the length of the shadow that can be formed on the bar having the height L1 is L2, the solar altitude (elevation angle) is A, and the azimuth angle B of the sun from the north-south axis is the shadow length magnification R, the north-south direction is possible. The shadow magnification Ry and the shadow magnification Rx in the east-west direction are respectively
R = L2 / L1 = (1 / tanA)
Ry = L2y / L1y = (1 / tanA) × cosB
Rx = L2x / L1x = (1 / tanA) × sinB
It becomes.

Here, assuming that the altitude (elevation angle) at 9 o'clock or 15 o'clock of the winter solstice of the installation site is A and the azimuth angle from the north-south axis is B, the highest arrival point of the junction box 105 is higher than the highest arrival point of the solar cell array. If the height of the connection box 105 from the lower end of the light receiving surface of the solar cell array 103 is H, the distance from the solar cell array 103 located closest to the connection box 105 is set in the north-south direction.
H × (1 / tanA) × cosB or more,
If each of H × (1 / tanA) × sinB or more is opened in the east-west direction, it can be considered that the influence of the shadow of the connection box 105 does not reach the annual power generation amount of the solar cell array 103.

In this embodiment, the distance relationship between the solar cell array 103 and the connection box 105 is described. However, since the solar cell array 103 is an assembly of solar cell modules, the distance between the solar cell module and the connection box 105 is about the above distance. The distance is the same.

[Embodiment 4]
The photovoltaic power generation system according to the fourth embodiment will be described with reference to the drawings.

In the photovoltaic power generation system shown in FIG. 5, the connection box 105 is arranged at the corner of the solar cell array 103. In the case where as many solar cell modules as possible are arranged on a limited roof surface as in a solar power generation system for a house, it is desired to configure a solar cell array without a gap on the installation surface.

In this embodiment, it is a large-scale solar power generation system, and the number of solar cell modules used is very large. In the case of such a structure, instead of laying the modules all over the installation surface to form the solar cell array 103, a maintenance passage 107 is provided so that a person can pass between the solar cell arrays during maintenance. If a plurality of solar cell arrays 103 are arranged in the provided state, it is convenient for system operation. Note that no solar cell module is installed in the maintenance passage 107.

Therefore, in this embodiment, the connection box 105 is installed in the periphery of the solar cell array 103, but even if the shadow is applied to the maintenance passage 107, the solar cell module is present in the maintenance passage 107. Does not affect power generation.

When the width in the north-south direction of the maintenance passage 107 is Wy and the width in the east-west direction is Wx, when the height H from the lower end of the light receiving surface of the solar cell array 103 of the connection box 105 is set,
Wy ≧ H × (1 / tanA) × cosB,
Wx ≧ H × (1 / tanA) × sinB
If the relational expression is satisfied, the shadow of the junction box 105 is designed so as not to affect the annual power generation amount of the photovoltaic power generation system. For example, if the north latitude is roughly 35 degrees, the sun altitude at 9 or 15 o'clock in the winter solstice is 18 degrees and the azimuth is 43 degrees.
(1 / tan 18 °) × cos 43 ° = 2.3
(1 / tan18 °) × sin 43 ° = 2.1
It becomes. If the height from the lower end of the solar cell array 103 surface of the junction box 105 is 30 cm, a system that does not shadow the module is constructed if a passage width of 69 cm in the north-south direction and 62 cm in the east-west direction is secured. it can.

In addition, even if the passage width larger than this is provided, there is no influence of the shadow, but since the area occupied by the passage increases, the installation area where the solar cell module can be installed is reduced, and the power generation amount of the system is reduced. become.

From the above, by constructing the solar power generation system using the above formula, the most efficient solar power generation system can be constructed in consideration of the arrangement space of the solar cell array 103 and peripheral devices. Further, by using the junction box 105 of this embodiment, the width of the maintenance passage 107 can be reduced, and the efficiency of the photovoltaic power generation system can be improved.

In addition, although the case of the folded-plate roof was demonstrated in this embodiment, it is not restricted to a folded-plate roof, For example, a flat roof may be used and it may be used for the photovoltaic power generation system further installed on land.

Note that the present invention can be implemented in various other forms without departing from the spirit or main features thereof. Therefore, the above-mentioned embodiment is only a mere illustration in all points, and should not be interpreted limitedly. The scope of the present invention is indicated by the claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

The photovoltaic power generation system according to the present invention can be widely applied to all photovoltaic power generation systems.

DESCRIPTION OF SYMBOLS 101 Building 102 Folded plate roof 103 Solar cell array 104 Connection cable of solar cell string and connection box 105 Connection box 106 Connection cable of connection box and current collection box 107 Maintenance passage 110 Haze grip metal 111 Fixing bar 112 Wiring guide 201 Conventional Terminal block 202 Rear surface of connection box 203 Bottom surface of connection box 204 Hole for wiring at bottom surface of connection box 205 Connection terminal 206a High-potential wiring to the inside 206b Low-potential wiring to the inside 207 Screw 301 Connection used in the photovoltaic power generation system of the present invention Box terminal block 305a High potential wiring metal plate 305b Low potential wiring metal plate

Claims (11)

In a solar power generation system having a solar cell module, a string in which a plurality of the solar cell modules are connected in series, and a connection box to which a plurality of the strings are connected,
The said connection box has the connection terminal for connecting with the said string, and this connection terminal has an attachment angle, The solar power generation system characterized by the above-mentioned. In a solar power generation system having a solar cell module, a string in which a plurality of the solar cell modules are connected in series, and a connection box to which a plurality of the strings are connected,
The said connection box has the wiring of the metal plate which connects the electric power of these strings in parallel, The solar power generation system characterized by the above-mentioned. The solar power generation system according to claim 2,
The connection box has wiring of a metal plate for connecting the power of the plurality of strings in parallel, a part of the metal plate is formed in a comb shape, and each end of the comb shape and the wiring from the string are connected An electrically connected photovoltaic power generation system. The photovoltaic power generation system according to any one of claims 1 to 3,
The solar cell module is installed on the roof surface,
The solar power generation system which has the wiring holding mechanism for hold | maintaining the wiring from the said string so that it may not contact the said roof surface of the said connection box lower part in the lower part of the said connection box. The photovoltaic power generation system according to any one of claims 1 to 4,
The solar cell module is installed on a folded roof surface,
A width of the junction box is narrower than a width of a mountain portion of the folded plate roof, and the bottom surface of the junction box is fixed at a position lower than a mountain portion of the roof portion. The photovoltaic power generation system according to any one of claims 1 to 5,
With reference to the lower end of the installed solar cell module, the height of the junction box is H, the solar altitude at 9 or 15 o'clock of the winter solstice at the installation location of the solar power generation system is A, and the azimuth angle is B. sometimes,
A solar power generation system in which the solar cell module is installed with a distance of H × (1 / tanA) × cosB on the north side of the junction box. The photovoltaic power generation system according to any one of claims 1 to 5,
With reference to the lower end of the installed solar cell module, the height of the junction box is H, the solar altitude at 9 or 15 o'clock of the winter solstice at the installation location of the solar power generation system is A, and the azimuth angle is B. sometimes,
A solar power generation system in which the solar cell module is installed at a distance of H × (1 / tanA) × sinB on the east or west side of the junction box. The photovoltaic power generation system according to any one of claims 1 to 5,
A plurality of arrays in which the strings are arranged in parallel, and a passage is provided between the arrays,
With reference to the lower end of the installed solar cell module, the height of the junction box is H, the solar altitude at 9 or 15 o'clock of the winter solstice at the installation location of the solar power generation system is A, and the azimuth angle is B. sometimes,
A solar power generation system, wherein a width of the passage in a north-south direction is H × (1 / tanA) × cosB or more. The photovoltaic power generation system according to any one of claims 1 to 5,
In a solar power generation system having a solar cell module, a string in which a plurality of the solar cell modules are connected in series, and a connection box to which a plurality of the strings are connected,
A plurality of arrays in which the strings are arranged in parallel, and a passage is provided between the arrays,
With reference to the lower end of the installed solar cell module, the height of the junction box is H, the solar altitude at 9 or 15 o'clock of the winter solstice at the installation location of the solar power generation system is A, and the azimuth angle is B. sometimes,
The solar power generation system whose width in the east-west direction of the passage is not less than H × (1 / tanA) × sinB. A string in which a plurality of solar cell modules are connected in series is a connection box connected in parallel,
A connection box, wherein a connection terminal for connecting to the string has an attachment angle. A string in which a plurality of solar cell modules are connected in series is a connection box connected in parallel,
A junction box comprising metal plate wiring for connecting the power of the plurality of strings in parallel.

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