JP2012099764A - Photovoltaic power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photovoltaic power generation system in which the workability is enhanced, the amount of power generated from solar cell panels is increased, and deterioration of the solar cell panels due to extension of the solar cell panels or diffusion of Na plus ions in a glass substrate to the inside of a photoelectric conversion layer can be retarded.SOLUTION: The photovoltaic power generation system comprises a solar cell array connecting a plurality of solar cell strings each connecting a plurality of solar cell panels 1 generating power, and power conversion means 41 provided in each solar cell panel 1 and converting a DC power generated from each solar cell panel 1 into a desired AC power. Each solar cell panel 1 has ground means 43 for panel that grounds a part of the solar cell panel 1. The ground means 43 for panel is branched to connect the solar cell panel 1 and the negative electrode side where a DC power is input to the power conversion means 41.

Description

  The present invention relates to a solar cell, and more particularly to a thin film solar cell in which a power generation layer is formed by film formation.

  Conventionally, as shown in FIG. 17, the photovoltaic power generation system 100 includes a solar cell array 103 and power control for converting DC power generated by a plurality of solar cell panels 101 constituting the solar cell array 103 into AC power. Device (power conditioner) 105, and supplies AC power output from the power control device 105 to the power system 110 via the insulation transformer 106, distribution board 107, switch 108, and transformer 109. .

  The solar battery panel array 103 of such a solar power generation system 100 includes, for example, four solar battery panels 101 connected in parallel to form a solar battery panel string 102, and, for example, three rows of solar battery panels The strings 102 are connected to each other in series.

  The DC power generated by each solar cell panel 101 is guided to the connection box 104 for each solar cell string 102. Therefore, the connection cables are connected to the connection box 104 by the amount corresponding to the solar cell strings 102 (for example, three circuits).

  The DC power from each solar cell panel string 102 guided to the connection box 104 by each wiring cable is collected by the connection box 104, output to one circuit, and guided to the power control device 105.

  The power control device 105 includes a booster circuit 105a, an inverter 105b, and a filter 105c. The power control device 105 converts the collected DC power guided from the connection box 104 to the power control device 105 into AC power and outputs the AC power. To do.

  The AC power converted by the power control device 105 is supplied to a distribution board 107 that is a power receiving facility through an insulating transformer 106. The AC power supplied to the distribution board 107 is converted to a desired AC voltage by the transformer 109 and then transmitted to the power system 110. Note that a switch 108 is provided between the distribution board 107 and the transformer 109 so that the circuit of the photovoltaic power generation system 100 linked to the power system 110 can be opened and closed.

  When a microcrystalline tandem thin-film silicon solar cell containing amorphous silicon is used for such a photovoltaic power generation system 100, as shown in FIG. 17, between the connection box 104 and the power control device 105. By providing the negative electrode grounding unit 111 and grounding the negative side of the power control device 105, or by applying a bias voltage to the positive side with a slight voltage, Na ions in the surface glass of the thin-film silicon-based solar cell generate power. Some have applied an electric field that is difficult to diffuse to the inside of the cell to suppress deterioration and deterioration (for example, Patent Document 1).

  However, in the photovoltaic power generation system 100 shown in FIG. 17, power control is performed after collecting a plurality of solar cell strings 102, so that a power control device 105 including an inverter 105 b having a relatively large capacity is required. Therefore, the wiring connection of the photovoltaic power generation system 100 is complicated, and it takes a lot of work.

  Normally, the capacity of the solar cell panel 101 is designed so that the output of the solar cell panel 101 matches the capacity of the inverter 105b of a predetermined standard. However, when the solar cell panel 101 is added, the power generation system is designed. Therefore, it is necessary to newly provide the capacity of the inverter 105b in accordance with the capacity of the photovoltaic power generation system 100, and it is necessary to replace the power converter 105 having the inverter 105b.

  Therefore, conventionally, a photovoltaic power generation system in which a small inverter unit is provided for each solar cell panel, the output from each solar cell panel is set to AC, and the solar cell panels are connected in parallel has been studied.

  However, when an inverter unit is provided for each solar cell panel, the inverter unit is heated by self-heating and a temperature rising atmosphere (for example, 50 ° C. to 70 ° C.) due to sunlight of the solar cell. . Therefore, since it becomes easy to generate | occur | produce the failure of an inverter, the effective cooling method of an inverter unit has been examined (for example, patent document 2 and patent document 3).

  Moreover, in order to suppress the rapid fluctuation | variation of the electric power output from a solar cell by the fluctuation | variation of solar radiation conditions, in patent document 4, an insulating film is provided in the photoelectric conversion layer side formed in the glass substrate of each solar cell panel. An invention in which a sheet-like electric double capacitor is installed is disclosed.

  Further, Patent Document 5 discloses that a GPS reception signal is used as an AC wave synchronization adjusting means of an inverter unit provided for each solar cell panel.

JP 2008-47819 A Japanese Patent Laid-Open No. 9-271179 JP 2002-111038 A Japanese Patent Publication No. 6-36431 JP-A-2005-116835

  However, the invention disclosed in Patent Document 1 has not been studied for a photovoltaic power generation system in which an inverter unit is provided for each panel of a thin film silicon solar cell.

  Moreover, in a thin film silicon solar cell, there is a light deterioration phenomenon. Therefore, in order to recover this deterioration, it is desirable that the temperature of the solar cell panel is about a temperature increased by sunlight (about 50 ° C. to 70 ° C.) rather than a low temperature. Therefore, when an inverter unit is installed in each solar cell panel, a method of cooling the inverter unit by effectively using the flow of airflow such as wind in a limited space, especially self-heating of the inverter unit is simple and effective. A method of dissipating heat is desired.

  Further, by providing a small capacity leveling capacitor for each output of the solar cell panel 101, the large capacity leveling capacitor installed at the input portion of the inverter 105b in FIG. 17 can be reduced in size and dispersed. it can. However, as in the invention described in Patent Document 4, in the form in which the entire photoelectric conversion layer and the entire electric double capacitor are electrically connected, in order to exert the leveling effect, the resistance of the electric double capacitor is reduced. A rise in voltage and further miniaturization are desired.

  The present invention has been made in order to solve the above-described problems, and improves workability, increases the power generation amount of the solar cell panel, increases the number of solar cell panels, and Na plus ions in the glass substrate. A photovoltaic power generation system capable of suppressing deterioration of a solar cell panel due to diffusion inside a photoelectric conversion layer is provided.

  In order to solve the above problems, according to the photovoltaic power generation system of the present invention, a solar cell array in which a plurality of solar cell strings in which a plurality of solar cell panels for generating electric power are connected is connected to each of the solar cell panels. Power conversion means for converting DC power generated by each solar cell panel into desired AC power, and each solar cell panel includes panel grounding means for grounding a part of the solar cell panel. The panel grounding means is branched to connect the solar cell panel and a negative electrode side for inputting DC power to the power conversion means.

  In general, in the case of a solar power generation system including a solar cell array in which a plurality of solar cell panels that generate DC output power are connected, a wiring cable led from each solar cell string constituting the solar cell array Each battery string is connected to a junction box. Therefore, as many wiring circuits as the number of solar cell strings are led from the solar cell array to the connection box. Thereafter, the DC voltage derived from each solar cell string is collected from the junction box and output as one circuit. The DC power output from the connection box is converted into AC power by the power converter and guided to the power supply system.

  Therefore, in the present invention, each solar cell panel is provided with power conversion means for converting DC power generated by the solar cell panel into desired AC power. Therefore, it can collect electric current from each solar cell panel as alternating current power. Further, the panel grounding means for grounding a part of the solar cell panel is branched to connect between the solar cell panel and the negative electrode side input to the power conversion means. The panel grounding means is connected to a frame or the like provided around the solar cell panel, and can discharge an electrostatic component generated in the solar cell panel and has a ground potential. Therefore, it is possible to perform grounding on the negative electrode side that is input to the power conversion means for each power conversion means. Therefore, the connection wiring of the solar power generation system is easily connected to each solar cell panel portion, so that the workability is improved, and Na plus ions in the glass substrate easily diffuse into the power generation cell inside the solar cell panel. In order not to apply the electric field, the solar cell power generation system using the solar cell panel in which the back surface electrode side potential of the solar cell is brought close to the ground potential and the alteration or deterioration is suppressed can be provided.

  In addition, in the case of a solar power generation system that converts DC power collected from the solar cell array into AC power using a power converter, when adding a solar cell panel, the capacity of the additional solar power generation system It was necessary to replace the power converter with an inverter having a suitable capacity.

  However, in the present invention, even if the capacity of the solar power generation system is changed by adding a solar cell panel or the like, the power conversion unit is provided for each solar cell panel. It is possible to respond by installing solar cell panels necessary for expansion instead of exchanging. Therefore, it becomes easy to increase the number of solar cell panels and to make individual designs.

  According to the solar power generation system of the present invention, the panel grounding portion provided in each solar cell panel, the external output unit to which the AC power converted by the power conversion unit is guided, and each solar cell string are configured. The panel grounding means connected to the panel grounding portion of each solar cell panel, and common grounding means for grounding via each panel grounding means, the common grounding means having the external output A synchronization signal for AC output is transmitted from the means to the power conversion means.

The common grounding means is electrically connected to the panel grounding portion of each solar cell panel constituting each solar cell string via the panel grounding means. The synchronization signal is transmitted from the external output means to the common grounding means of the solar cell array configured as described above. Therefore, the synchronization signal is transmitted to the power conversion means provided in each solar cell panel via the common grounding means and each panel grounding means. Therefore, the phase of the AC output of each solar cell panel can be easily and accurately synchronized.
Further, it is also possible to provide string grounding means for connecting to each panel grounding means in each solar cell string, and to connect to the common grounding means via this string grounding means. When the number of solar cell panels of each solar cell string is large and is located away from the common grounding means, it is preferable because the connection wiring is simplified.

  According to the photovoltaic power generation system of the present invention, it is provided with a recording device and a monitoring device to which a part of the common grounding means is connected, and each of the power conversion means has a unique signal for each power conversion means and the power. When there is an abnormality in the solar cell panel having the conversion means, an abnormality signal is transmitted.

  Each power conversion means transmits a unique signal for each power conversion means to identify each solar cell panel, and it is possible to check the power generation state of each solar cell panel, and there is an abnormality in the solar cell panel. If there is, an abnormal signal is transmitted, and each solar cell panel can be monitored. A part of the common grounding means is connected to the recording apparatus. As a result, the unique signal and abnormality signal transmitted from the power conversion means for each power conversion means can be transferred to the recording apparatus via the common grounding means and each panel grounding means for monitoring. For this reason, the common grounding means and the grounding means for each panel where the generated power does not flow can be used for signal transmission. Therefore, it becomes easy to receive and process signals such as unique signals and abnormal signals in the recording apparatus.

  According to the solar power generation system of the present invention, the power conversion is provided on the back side opposite to the light receiving surface of the solar cell panel for generating electric power, and converts the DC power generated by each solar cell panel into desired AC power. And a heat dissipating means for dissipating the self-heating of the power conversion means is provided on the back surface of each of the solar cell panels in the vicinity of the power conversion means. A plurality of projecting portions projecting from the surface of the means main body and extending away from the power conversion means, and the installation direction of the heat dissipating means main body is adjustable. To do.

  The heat dissipating means provided on the back surface of the solar cell panel in the vicinity of the power converting means and dissipating the heat generated by the power converting means is extended toward the heat dissipating means main body and the direction away from the power converting means. And having a plurality of protrusions. In addition, the heat dissipating means main body having the projecting portion has a variable installation direction. The airflow flowing on the back side of the solar cell panel varies depending on the installation form, but the installation direction of the heat dissipating means is adjusted for each solar cell panel in the direction in which the airflow on the back side easily flows along the protruding portion of the heat dissipating means. Thereby, the heat dissipation performance of the heat dissipation means can be improved. Therefore, the self-heating of the power conversion means can be effectively radiated by the heat radiating means regardless of the installation form of the solar cell panel.

  According to the solar power generation system of the present invention, the heat radiating means body has a shape that tapers in a direction away from the power conversion means.

  As it goes away from the power conversion means, the amount of heat transferred from the power conversion means to the heat dissipation means is reduced.

  For this reason, the heat radiating means main body is tapered toward the direction away from the power conversion means. Thereby, the surface area of a heat radiating means main body can be made small toward the direction away from a power conversion means. Therefore, it is possible to reduce the size of the heat radiating means and reduce the cost of creating the heat radiating means. In addition, by not providing heat dissipation means in a region where the effect of heat dissipation is low, it becomes difficult to block the entire airflow on the back side of the solar cell panel, and the airflow heated by heat dissipation can be sequentially eliminated, so The heat radiation becomes more effective, and it becomes possible to suppress the failure of the power conversion means and improve the reliability.

  According to the solar power generation system of the present invention, the solar battery panel includes power conversion means that is provided in each solar cell panel and converts DC power generated by each solar cell panel into desired AC power. Capacitors are provided between the constituent cells.

  Normally, a leveling capacitor is installed between the solar cell array and the power converter to stabilize the operation of the inverter provided in the power converter by suppressing sudden fluctuations in the DC power of the solar panel due to fluctuations in solar radiation. It is preferable to install. However, since the leveling capacitor provided in such a photovoltaic power generation system has a large capacity, there is a problem that an installation space of the power conversion device provided with the inverter is increased and the cost of the power conversion device is increased. .

  Therefore, power conversion means is provided in each solar cell panel, a leveling capacitor is held for each solar cell panel, and this leveling capacitor is further provided between cells constituting the solar cell panel. Therefore, even if there is a sudden fluctuation in the output due to a decrease in the amount of power generated by some cells of the solar panel due to the occurrence of shade, the output of the solar panel is provided by each capacitor provided between the cells. Can be effectively smoothed. Therefore, since the output fluctuation can be absorbed for each solar cell panel, the performance of the photovoltaic power generation system can be improved.

  Moreover, since a small-capacitance capacitor is used for a low voltage between cells, the withstand voltage of each leveling capacitor can be reduced. Therefore, the manufacturing management of the capacitor becomes easy. Therefore, it can be set as the solar power generation system excellent in withstand voltage.

  According to the method for grounding a photovoltaic power generation panel of the present invention, a panel for grounding a part of each of the solar cell panels constituting a solar cell array in which a plurality of solar cell strings in which a plurality of solar cell panels for generating electric power are connected are connected. The grounding means is branched, and each of the solar cell panels and the DC power to the power conversion means provided in each of the solar cell panels and converting the DC power generated by each of the solar cell panels into desired AC power Is connected to the negative electrode side for inputting.

  According to the monitoring method by the solar power generation system of the present invention, each solar cell panel constituting a solar cell array in which a plurality of solar cell strings in which a plurality of solar cell panels for generating electric power are connected is connected is provided. A unique signal from power conversion means for converting DC power generated by the solar cell panel into desired AC power, and an abnormal signal transmitted when there is an abnormality in the solar cell panel having the power conversion means. Monitoring is performed by a panel grounding means for grounding a part of the solar battery panel, and a recording device and a monitoring device connected to the common grounding means for grounding via the panel grounding means.

  According to the cooling method of the power conversion means of the present invention, the direct-current power generated by each of the solar cell panels is provided on the back side opposite to the light receiving surface of the plurality of solar cell panels that generate electric power. A heat dissipating body of the heat dissipating means for dissipating the self-heating of the power converting means on the back surface of each of the solar cell panels in the vicinity of the power converting means for converting to electric power, and protruding from the surface of the heat dissipating means main body A plurality of protrusions extending in a direction away from the conversion means are provided, and the installation direction of the heat dissipation means main body is adjusted for each installation direction of the solar cell panel.

  According to the leveling method of the generated power of the solar cell panel according to the present invention, the power conversion means provided in each of the plurality of solar cell panels and converting the DC power generated by each solar cell panel into desired AC power is provided. A capacitor is provided between each cell of the solar cell panel provided, and the power generated by each solar cell panel is leveled.

  Each solar cell panel is provided with power conversion means for converting the DC power generated by the solar cell panel into desired AC power. Therefore, it can collect electric current from each solar cell panel as alternating current power. Furthermore, a common grounding means is provided via a panel grounding means for grounding the solar cell panel, and the solar cell panel and the negative electrode input to the power conversion means are connected. Therefore, grounding can be performed for each power conversion means. Accordingly, the back electrode of the solar cell is provided so that the connection wiring of the solar power generation system is facilitated and the workability is improved and the solar cell panel is not provided with an electric field in which Na plus ions in the glass substrate easily diffuse into the power generation cell. A solar power generation system using a solar cell panel in which the side potential is brought close to the ground potential and deterioration and deterioration are suppressed can be obtained.

  Moreover, even if the capacity of the photovoltaic power generation system changes due to the addition of solar cell panels, etc., power conversion means is provided for each solar cell panel, so there is no need to replace the already installed power conversion means It becomes. Therefore, it becomes easy to increase the number of solar cell panels and to make individual designs.

  In addition, since the synchronization signal is transmitted from the external output means to the common grounding means of the solar cell array, the phase of the AC output from the power conversion means provided in each solar cell panel can be easily and accurately synchronized. The quality of the AC output of the solar cell array can be easily ensured.

  Since a part of the common grounding means of the solar cell array is connected to the recording device and the monitoring device, each power conversion means determines the power generation state of each solar cell panel from a unique signal sent to each power conversion means. In addition to being able to confirm, when there is an abnormality in the solar cell panel, an abnormal signal is transmitted, monitoring, recording and processing of each solar cell panel are facilitated, and the reliability of the photovoltaic power generation system is improved.

  Further, a heat dissipating means for dissipating the heat generated by the power converting means is provided on the back surface of the solar cell panel in the vicinity of the power converting means, and the disposing direction of the heat dissipating means is variable. Therefore, by adjusting the installation direction of the heat dissipation means for each solar cell panel in the direction in which the airflow flowing on the back side of the solar cell panel is easy to flow, the heat dissipation performance of the heat dissipation means is improved and the self-heating of the power conversion means is effectively dissipated. It is possible to suppress the failure of the power conversion means and improve the reliability.

  In addition, the power conversion means is provided in each solar cell panel, and the leveling capacitor is provided between the cells constituting each solar cell panel. Therefore, even if the power generation amount of some cells of the solar battery panel is reduced and the output fluctuates suddenly, the output change of the solar battery panel can be effectively smoothed. Therefore, it is possible to improve the performance of the photovoltaic power generation system by absorbing sudden fluctuations in output.

It is a schematic diagram explaining the structure of the photovoltaic cell which concerns on 1st Embodiment of this invention. It is a part of schematic diagram explaining the manufacturing process of the solar cell module which concerns on 1st Embodiment. It is a part of schematic diagram explaining the manufacturing process of the solar cell module which concerns on 1st Embodiment. It is a part of schematic diagram explaining the manufacturing process of the solar cell module which concerns on 1st Embodiment. It is a part of schematic diagram explaining the manufacturing process of the solar cell module which concerns on 1st Embodiment. It is a part of schematic diagram explaining the manufacturing process of the solar cell module which concerns on 1st Embodiment. 1 is a schematic configuration diagram of a photovoltaic power generation system according to a first embodiment. It is a schematic block diagram of the solar cell panel provided with the AC conversion unit shown in FIG. It is the schematic which shows that a heat sink with a fin is provided in the solar cell panel provided with the AC-ized unit shown in FIG. It is a longitudinal cross-sectional schematic block diagram of the solar cell panel provided with the heat sink with a fin shown in FIG. It is a schematic block diagram of the heat sink with a fin shown in FIG. It is a schematic block diagram of the solar energy power generation system which concerns on 2nd Embodiment. It is a schematic block diagram of the solar energy power generation system which concerns on 3rd Embodiment. It is a longitudinal cross-sectional schematic block diagram of the solar cell panel which has a capacitor | condenser for every solar cell power generation cell which concerns on 4th Embodiment. It is an equivalent circuit schematic of the solar cell panel shown in FIG. It is an equivalent circuit schematic of the solar cell panel which has a capacitor | condenser between several solar cell power generation cells which concern on 5th Embodiment. It is a schematic block diagram of the conventional solar power generation system.

[First Embodiment]
Hereinafter, the solar cell module used for the solar power generation system according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 6.
FIG. 1 is a schematic diagram illustrating the configuration of the solar battery cell of this embodiment. 2 to 6 are schematic views showing manufacturing steps for modularizing the solar battery cell shown in FIG.

The solar cell module described in this embodiment is a tandem silicon solar cell module in which the photoelectric conversion layer 4 is formed, and is sealed with an unillustrated adhesive filling sheet (EVA) and a back sheet (PET / AL / PET structure). The aluminum frame frame is attached to the periphery of the solar cell panel through a gasket (not shown).
The back sheet (PET / AL / PET structure) may be a glass substrate, and the aluminum frame frame provided around the solar cell panel can be omitted if the solar cell module strength can be secured.

  As shown in FIG. 1, the photoelectric conversion device 5 includes a substrate 6, a transparent electrode layer 7, a first cell layer 91 (amorphous silicon type) and a second cell layer 92 (crystalline silicon type) as the photoelectric conversion layer 4. The intermediate contact layer 93 and the back electrode layer 8 are provided. Here, the silicon-based is a general term including silicon (Si), silicon carbide (SiC), and silicon germanium (SiGe). Further, the crystalline silicon system means a silicon system other than the amorphous silicon system, and includes microcrystalline silicon and polycrystalline silicon.

(1) FIG. 2 (a):
A soda float glass substrate (for example, 1.4 m × 1.1 m × plate thickness: 3.0 mm to 4.5 mm) is used as the substrate 6. The end face of the substrate 6 is preferably subjected to corner chamfering or R chamfering to prevent damage due to thermal stress or impact.

(2) FIG. 2 (b):
A transparent electrode film mainly composed of a tin oxide film (SnO ₂ ) is formed as the transparent electrode layer 7 at a film thickness of about 500 nm to 800 nm at a temperature of about 500 ° C. using a thermal CVD apparatus (not shown). At this time, a texture film (not shown) having appropriate irregularities may be formed on the surface of the transparent electrode film. As the alkali barrier film, a silicon oxide film (SiO ₂ ) may be formed at a temperature of about 50 to 150 nm and a thermal CDV device at about 500 ° C. (not shown).

(3) FIG. 2 (c):
Thereafter, the substrate 6 is grounded to an XY table (not shown), and the first harmonic (1064 nm) of the YAG laser is irradiated from the film surface side of the transparent electrode film as indicated by the arrow in the figure. The laser power is adjusted so as to be suitable for the processing speed, and the substrate 6 and the laser beam are moved relative to each other in the direction perpendicular to the series connection direction of the power generation cells so that the groove 10 is formed. And laser etching into a strip shape having a predetermined width of about 6 mm to 15 mm.

(4) FIG. 2 (d):
As the first cell layer 91, a p layer, an i layer, and an n layer made of an amorphous silicon thin film are formed by a plasma CVD apparatus (not shown). Using SiH ₄ gas and H ₂ gas as main raw materials, a reduced pressure atmosphere: 30 Pa or more and 1000 Pa or less, a substrate temperature: about 200 ° C., an amorphous silicon p layer on the transparent electrode layer 7 from the side where sunlight enters, An amorphous silicon i layer and an amorphous silicon n layer are formed in this order. The amorphous silicon p layer is mainly made of amorphous B-doped silicon and has a thickness of 10 nm to 30 nm. The amorphous silicon i layer has a thickness of 200 nm to 350 nm. The amorphous silicon n layer is mainly P-doped silicon containing microcrystalline silicon in amorphous silicon and has a thickness of 30 nm to 50 nm. A buffer layer may be provided between the amorphous silicon p layer and the amorphous silicon i layer in order to improve interface characteristics.

  Next, a crystalline material as the second cell layer 92 is formed on the first cell layer 91 by a plasma CVD apparatus at a reduced pressure atmosphere: 3000 Pa or less, a substrate temperature: about 200 ° C., and a plasma generation frequency: 40 MHz or more and 100 MHz or less. A silicon p layer, a crystalline silicon i layer, and a crystalline silicon n layer are sequentially formed. The crystalline silicon p layer is mainly composed of B-doped microcrystalline silicon and has a thickness of 10 nm to 50 nm. The crystalline silicon i layer is mainly microcrystalline silicon and has a film thickness of 1.2 μm or more and 3.0 μm or less. The crystalline silicon n layer is mainly composed of P-doped microcrystalline silicon and has a thickness of 20 nm to 50 nm. The crystalline silicon n layer may be an amorphous n layer.

  In forming the i-layer film mainly composed of microcrystalline silicon by the plasma CVD method, the distance d between the plasma discharge electrode and the surface of the substrate 6 is preferably 3 mm or more and 10 mm or less. If it is smaller than 3 mm, it is difficult to keep the distance d constant from the accuracy of each component device in the film forming chamber corresponding to the large substrate, and there is a possibility that the discharge becomes unstable because it is too close. When it is larger than 10 mm, it is difficult to obtain a sufficient film forming speed (1 nm / s or more), and the uniformity of the plasma is lowered and the film quality is lowered by ion bombardment.

  An intermediate contact layer 93 serving as a semi-reflective film is provided between the first cell layer 91 and the second cell layer 92 in order to improve contact and to obtain current matching. As the intermediate contact layer 93, a ZnO (Ga or AL-doped ZnO) film having a film thickness of 20 nm to 100 nm is formed by a sputtering apparatus (not shown) using a target: Ga-doped ZnO sintered body. Further, the intermediate contact layer 93 may not be provided.

(5) FIG. 2 (e)
The substrate 6 is grounded to the XY table, and the second harmonic (532 nm) of the laser diode pumped YAG laser is irradiated from the film surface side of the photoelectric conversion layer 4 as indicated by the arrow in the figure. Pulse oscillation: 10 kHz to 20 kHz, laser power is adjusted so as to be suitable for the processing speed, and laser etching is performed so that grooves 11 are formed on the lateral side of the laser etching line of the transparent electrode layer 7 from about 100 μm to 150 μm. To do. Further, this laser may be irradiated from the substrate 6 side. In this case, the photoelectric conversion layer 4 is photoelectrically generated by utilizing a high vapor pressure generated by the energy absorbed by the amorphous silicon-based first cell layer 91. Since the conversion layer 4 can be etched, a more stable laser etching process can be performed. The position of the laser etching line is selected in consideration of positioning intersection so as not to intersect with the etching line in the previous process.

(6) FIG. 3 (a)
An Ag film / Ti film is formed as the back electrode layer 8 by a sputtering apparatus at a reduced pressure atmosphere and at a film forming temperature of 150 ° C. to 200 ° C. In this embodiment, an Ag film: 150 nm or more and 500 nm or less, and a Ti film having a high anticorrosion effect: 10 nm or more and 20 nm or less are stacked in this order to protect them. Alternatively, the back electrode layer 8 may have a laminated structure of an Ag film having a thickness of 25 nm to 100 nm and an Al film having a thickness of 15 nm to 500 nm. In the case where long wavelength side reflected light of 600 nm or more is required, a laminated structure of a Cu film having a thickness of about 100 nm to 450 nm and a Ti film having a thickness of about 5 nm to 150 nm may be used. . For the purpose of reducing contact resistance between the crystalline silicon n layer and the back electrode layer 8 and improving light reflection, a ZnO film having a thickness of 50 nm or more and 100 nm or less is formed between the photoelectric conversion layer 4 and the back electrode layer 8 by a sputtering apparatus. A (Ga or AL-doped ZnO) film may be formed.

(7) FIG. 3 (b)
The substrate 6 is grounded to an XY table, and the second harmonic (532 nm) of the laser diode pumped YAG laser is irradiated from the substrate 6 side as indicated by the arrow in the figure. The laser light is absorbed by the photoelectric conversion layer 4, and the back electrode layer 8 is exploded and removed using the high gas vapor pressure generated at this time. Pulse oscillation: laser power is adjusted so as to be suitable for the processing speed from 1 kHz to 50 kHz, and laser etching is performed so that grooves 12 are formed on the lateral side of the laser etching line of the transparent electrode layer 7 from 250 μm to 400 μm. .

(8) FIG. 3 (c) and FIG. 4 (a)
By dividing the power generation region, the effect of the short-circuiting of the serially connected portion by laser etching at the film edge around the edge of the substrate 6 is removed. The substrate 6 is grounded to the XY table, and the second harmonic (532 nm) of the laser diode pumped YAG laser is irradiated from the substrate 6 side. Laser light is absorbed by the transparent electrode layer 7 and the photoelectric conversion layer 4, and the back electrode layer 8 explodes using the high gas vapor pressure generated at this time, and the back electrode layer 8 / photoelectric conversion layer 4 / transparent electrode layer 7 is removed. Pulse oscillation: 1 kHz or more and 50 kHz or less, the laser power is adjusted so as to be suitable for the processing speed, and the position of 5 nm to 20 mm from the end of the substrate 6 is placed in the X-direction insulating groove as shown in FIG. Laser etching is performed to form 16. 3C is a cross-sectional view in the X direction in which the photoelectric conversion layer 4 is cut in the direction connected in series. Therefore, the back electrode layer 8 / photoelectric sensor is originally located at the insulating groove 16 position. A state corresponding to the peripheral film removal region 14 where the conversion layer 4 / transparent electrode layer 7 has been removed by polishing should be present (see FIG. 4A). For convenience, the insulating groove formed to represent the Y-direction cross section at this position will be described as the X-direction insulating groove 16. At this time, the Y-direction insulating groove does not need to be provided because the film surface polishing removal process of the peripheral film removal region 14 of the substrate 6 is performed in a later process.

  The insulating groove 16 is preferable because etching is terminated at a position of 5 nm to 15 mm from the edge of the substrate 6, thereby exhibiting an effective effect for suppressing moisture penetration from the outside into the solar cell module from the end of the solar cell panel. .

  The laser light in the above steps is a YAG laser, but there are some that can use a YVO4 laser, a fiber laser, and the like.

(9) FIG. 4 ((a): view from the solar cell film surface side, (b): view from the substrate side of the light receiving surface)
In order to ensure a sound adhesion / seal surface with the back sheet 24 (see FIG. 5) through EVA or the like in a later process, the laminated film around the substrate 6 (peripheral film removal region 14) has a step and is peeled off. Therefore, the peripheral film removal region 14 is formed by removing this film. In removing the film over the entire periphery of the substrate 6 at 5 to 20 mm from the end of the substrate 6, the X direction is closer to the end of the substrate 6 than the insulating groove 16 provided in the step of FIG. Removes the back electrode layer 8 / photoelectric conversion layer 4 / transparent electrode layer 7 on the edge side of the substrate 6 with respect to the groove 10 near the edge side of the substrate 6 using grinding stone polishing, blast polishing, or the like. Polishing debris and abrasive grains are removed by cleaning the substrate 6.

(10) FIG. 4 (a) and FIG. 4 (b)
Current is collected using a copper foil from the back electrode layer 8 of the solar power generation cell 15 at one end arranged in series and the back electrode layer 8 of the current collecting cell connected to the solar power generation cell 15 at the other end. Then, processing is performed so that power can be taken out from the portion of the terminal box 23 (see FIG. 5A) on the back surface of the solar cell panel. The copper foil for current collection arrange | positions the insulating sheet wider than copper foil width | variety, in order to prevent a short circuit with each part.
After the current collecting copper foil is disposed at a predetermined position, an adhesive filler sheet (not shown) made of EVA (ethylene vinyl acetate copolymer) or the like is provided so as to cover the entire solar cell module 2 and not protrude from the substrate 6. )).
A back sheet 24 having a high waterproof effect is grounded on the adhesive filler sheet. In the present embodiment, the back sheet 24 has a three-layer structure of PET sheet / AL foil / PET sheet so that the waterproof and moisture proof effect is high.
An opening through window is provided at the attachment portion of the terminal box 23 of the back sheet 24 to take out the copper foil for current collection. In the opening through window portion, a plurality of insulators are grounded between the back sheet 24 and the back electrode layer 8 to suppress intrusion of moisture and the like from the outside.
The adhesive sheet (EVA) is cross-linked while degassing the inside of the backsheet 24 up to a predetermined position in a reduced pressure atmosphere with a laminator device (not shown) and pressing at about 150-160 ° C. And tightly seal.
The adhesive filler sheet is not limited to EVA, and an adhesive filler having a similar function such as PVB (polyvinyl butyral) can be used. In this case, the processing is performed by optimizing the conditions such as the pressure bonding procedure, temperature and time.

(11) FIG. 5 (a)
The terminal box 23 is attached to the back surface of the solar cell module 2 (see FIG. 4) with an adhesive.
(12) FIG. 5 (b)
The copper foil and the output cable of the terminal box 23 are connected by solder or the like, and the inside of the terminal box 23 is filled with a sealing agent (potting agent) and sealed. This completes the solar cell panel 1 (see FIG. 5C).
(13) FIG. 5 (c)
A power generation inspection and a predetermined performance test are performed on the solar cell panel 1 formed through the steps up to FIG. The power generation inspection is performed using a solar simulator of AM1.5 and solar radiation standard sunlight (1000 W / m ² ). The power generation inspection may be performed after the solar cell module 2 is completely completed, or may be performed before the aluminum frame frames 3L and 3S (see FIG. 6) are attached, and is not particularly limited.
(14) FIG. 5 (d)
Before and after the power generation inspection (FIG. 5C), a predetermined performance inspection is performed including an appearance inspection.

(15) FIG.
Around the solar cell module 2, strength is added to the solar cell module 2, and aluminum frame frames 3 </ b> L and 3 </ b> S serving as attachment seats are attached. It is preferable to securely hold the solar cell module 2 and the aluminum frame frames 3L and 3S through rubber gaskets or the like while maintaining elasticity. Thus, the solar cell panel 1 is completed.

In the above embodiment, the tandem silicon solar cell has been described as the solar cell, but the present invention is not limited to this example. For example, amorphous silicon solar cells, crystalline silicon solar cells including microcrystalline silicon, silicon germanium solar cells, and other types such as triple solar cells that are appropriately selected from the above solar cells and multi-junction The same applies to solar cells.
Furthermore, the present invention can be similarly applied to a solar cell manufactured on a non-light-transmitting substrate such as a metal substrate or the like, on which light is incident from the side opposite to the substrate.

Next, a solar power generation system using the solar battery panel manufactured as described above will be described with reference to FIGS.
FIG. 7 shows a schematic configuration diagram of the photovoltaic power generation system of the present embodiment. FIG. 8 is a schematic configuration diagram of the solar cell panel shown in FIG.

  The solar cell panel 1 has a plurality (for example, four rows) of solar cell panels 1 that generate DC power (electric power) connected in parallel (for example, three columns) connected in parallel (for example, three rows). A solar cell array 33 and an AC unit (power conversion means) that is provided in each solar cell panel 1 and converts the DC power generated by each solar cell panel 1 into AC power (desired AC power). ing.

The solar power generation system 30 can convert DC power generated by power generation from each solar cell panel 1 into AC power by an AC unit (not shown) described later and output the AC power. The solar cell panels 1 including such AC units are connected in parallel to each other to form, for example, three rows of solar cell strings 32.
In each solar cell panel 1, the AC output of the solar cell array 33 is performed by performing MPPT control (Maximum Power Point Tracking) that follows the optimum operating point at which the output is maximized in the AC unit. Is preferable for efficiently obtaining.

  Such solar cell strings 32 are connected to each other in parallel to form a solar cell array 33 and connected to a connection box 34. The solar cell array 33 connecting the solar cell strings 32 in parallel and the connection box 34 are connected by a single circuit wiring cable, and the connection wiring is simplified.

  The AC power collected from the solar cell array 33 to the connection box 34 is guided from the connection box 34 to a power controller (external output means) 35. The two-phase AC power collected in the connection box 34 is three-phased by the power controller 35 and output.

The AC power that has been three-phased by the power controller 35 is supplied to a distribution board 37 that is a power receiving facility through an insulating transformer 36. The AC power supplied to the distribution board 37 is converted to a desired AC voltage by the transformer 39 and then transmitted to the power system 40. A switch 38 is provided between the distribution board 37 and the transformer 39 so that a power transmission circuit for power to the power system 40 can be opened and closed.
The connection box 34, power controller 35, insulation transformer 36, distribution board 37, and switch 38 are each grounded by a grounding means such as a ground wire.

FIG. 8 shows a schematic configuration diagram of a solar cell panel including an AC unit.
The solar cell panel 1 includes an AC unit 41 in a terminal box (indicated by a dotted line) 23 provided on the back surface thereof. The solar cell panel 1 has a panel ground wire (panel grounding means) 43 connected to an aluminum frame 3L (see FIG. 6) or an aluminum frame 3S (see FIG. 6) attached to the outer periphery thereof. Yes. Here, as an example, it is assumed that a panel ground wire is connected to the aluminum frame 3L.

  The AC unit 41 is connected to a copper foil (collecting copper foil) 42 from which the DC power of the solar cell panel 1 is output, and the DC power generated by the solar cell panel 1 is guided. . The AC unit 41 includes a booster circuit 41a, an inverter 41b, and a filter 41c.

  The DC power generated by the solar cell panel 1 transmitted to the AC unit 41 is boosted by the booster circuit 41a and then converted into AC power by the inverter 41b. The AC power converted by the inverter 41 b is output from the output cable 45 connected to the AC unit 41 with noise removed by the filter 41 c.

  An aluminum frame 3L or 3S is used as a panel grounding portion of the solar cell panel 1. Moreover, in the solar cell panel without the aluminum frame frames 3L and 3S, it is preferable to provide a terminal portion capable of connecting a ground potential around the terminal box 23 or a part of the periphery of the solar cell panel.

  The opposite end of the panel ground wire 43 connected to the aluminum frame 3L is grounded. In addition, the panel ground wire 43 is branched at a midway position and connected to the negative electrode side to be input to the AC unit 41 via a backflow prevention diode. If the AC unit 41 itself has a protection circuit, the backflow prevention diode may be omitted.

  In this way, the panel ground wire 43 is branched and connected to the negative electrode side that is input from the solar cell panel 1 to the AC unit 41, thereby using the panel ground wire 43 for each AC unit 41. In addition, the negative electrode side can be set to the ground potential. Therefore, even when a microcrystalline tandem thin film silicon solar cell containing amorphous silicon is used as the solar cell module 2 (see FIG. 6), Na plus ions in the surface glass of the thin film silicon solar cell generate power. It is possible to improve the reliability by suppressing deterioration and deterioration of the solar battery power generation cell 15 (see FIG. 6) due to the application of an electric field that is difficult to diffuse inside the cell.

Next, the finned heat dissipating plate provided in the solar cell panel including the AC unit shown in FIG. 8 will be described with reference to FIGS. 9 to 11.
FIG. 9 shows that a finned heat dissipating plate is provided on the back side opposite to the light receiving surface of the solar cell panel. FIG. 10 is a schematic vertical sectional view of a solar cell panel provided with the finned heat dissipation plate shown in FIG. Further, FIG. 11 shows a schematic configuration diagram of the finned heat dissipation plate shown in FIG.

  The AC unit 41 built in the terminal box 23 (shown by a dotted line) provided on the back side opposite to the light receiving surface of the solar cell panel 1 is a booster circuit 41a constituting the AC unit 41. (See FIG. 8) and the inverter 41b (see FIG. 8) self-heat. Therefore, on the back surface side of the solar cell panel 1 in the vicinity of the terminal box 23 in which the AC unit 41 is built in, as shown in FIG. ) 50 is provided.

  As shown in FIG. 11, the finned heat sink 50 protrudes from the surfaces of the heat sink main body (heat dissipating means main body) 51 and the finned heat sink 50 on the side opposite to the solar cell panel 1 and from the AC unit 41. And a plurality of fins (protrusions) 52 extending in a direction away from each other.

  The heat sink main body 51 has a shape that tapers in a direction away from the AC unit 41. For example, as shown in FIG. 9, the bottom side is the terminal box 23 and the AC unit 41 side. The apex side has a substantially triangular shape in a direction away from the AC unit 41.

  The heat radiating plate body 51 is formed in a substantially triangular shape by a thin flat plate parallel to the back surface of the solar cell panel 1, and is made of a material having high thermal conductivity such as copper subjected to corrosion resistance treatment by aluminum alloy or nickel plating. It is manufactured.

  The self-heating of the terminal box 23 that is a heat source is less likely to be transferred as the distance from the terminal box 23 increases. Therefore, the surface area of the heat sink main body 51 can be gradually reduced by making the heat sink main body 51 into a tapered substantially triangular shape. Therefore, it is possible to reduce the cost by miniaturizing the finned heat sink 50. Moreover, by not providing the finned heat sink 50 in the region where the effect of heat dissipation is low, it becomes difficult to inhibit the entire airflow on the back surface side of the solar cell panel 1, and the airflow heated by heat dissipation can be sequentially eliminated. Therefore, the heat radiation by the finned heat sink 50 becomes more effective, and the failure of the AC unit 41 can be suppressed and the reliability can be improved.

  The fin 52 provided in the heat sink main body 51 is the same as the heat sink main body 51 and is a high thermal conductivity material such as an aluminum alloy or copper, and protrudes from the surface of the heat sink main body 51 opposite to the back surface of the solar cell panel 1. A plurality are provided. Each fin 52 extends in a direction away from the AC unit 41 and is provided to be substantially parallel to each other.

  A heat transfer body 53 that transfers the self-heating of the AC unit 41 to the finned heat sink 50 is provided on the bottom side of the substantially triangular heat sink main body 51. The heat transfer body 53 is a high thermal conductivity material such as an aluminum alloy or copper, similar to the heat sink main body 51 and the fins 52. The self-heating of the AC unit 41 is transferred to the heat transfer body 53 made of aluminum alloy or copper and radiated from the heat dissipating body 51 and the fins 52.

  As shown in FIGS. 9 and 10, the heat transfer body 53 is inserted and fixed while being sealed at one end of the side wall of the terminal box 23. Further, the other end of the heat transfer body 53 is connected to the heat radiating plate main body 51 by a mounting direction fixture 54. The heat transfer body 53 has a substantially cylindrical shape, and the end of the heat transfer body 53 on the side of the heat radiating plate main body 51 is formed in a concave shape. Due to the concave shape of the heat transfer body 53, a part of the bottom side of the heat radiating plate body 51 is sandwiched between the heat transfer bodies 53 as shown in FIG. Yes.

  Bolts 54 a constituting the mounting direction fixtures 54 penetrate through the ends of the heat sink body 51 and the heat transfer body 53 so as to be orthogonal to the axial direction of the heat transfer body 53. . Between the heat transfer body 53 and the bolt 54a, a washer 54b constituting the mounting direction fixture 54 is provided.

Next, adjustment of the direction of the finned heat transfer plate 50 provided in each solar cell panel 1 will be described with reference to FIGS. 9 and 11.
The solar cell array 33 (see FIG. 7) installed outdoors or the like passes through each solar cell panel 1 through an air flow such as wind. It has been found that the direction of the flow often depends on the installation location and installation direction of the solar cell panel 1.

  Therefore, the heat sink main body 51 of the finned heat sink 50 provided in each solar cell panel 1 can be fixed at an angle θ from the axial direction Z of the heat transfer body 53. The inclination angle θ of the heat radiating plate main body 51 may be appropriately changed depending on the installation location and installation direction of the solar cell panel 1, and the main flow direction of the air flow passing through each solar cell panel 1 (in FIG. 11). Each solar cell panel 1 is installed as a solar cell array 33 by adjusting so as to be substantially parallel to the direction in which the fins 52 extend).

  After the heat sink main body 51 is inclined by the angle θ with respect to the axial direction Z of the heat transfer body 53, the bolt 54b is tightened. Thereby, the finned heat sink 50 can be fixed to the solar cell panel 1 so that the extending direction of the fins 52 is oriented in a direction suitable for the air flow passing through the solar cell panel 1. Therefore, the main flow direction of the air flow passing through the solar cell panel 1 is easy to pass between the fins 52. Accordingly, the self-heating of the AC unit 41 can be transferred to the finned radiator plate 50 using the air flow passing through the solar panel 1 to effectively radiate the heat, and the solar cell panel by the irradiated sunlight. Since the temperature of 1 is not excessively cooled, deterioration of the solar cell panel due to the thin film silicon photoelectric conversion layer can be continuously suppressed.

As described above, the photovoltaic power generation system 30 according to the present embodiment has the following effects.
An AC unit (power conversion means) 41 that converts DC power (power) generated by the solar cell panel 1 into AC power (desired AC power) is provided in the terminal box 23 of each solar cell panel 1. Therefore, AC power can be collected from each solar cell panel 1 and collected in the junction box 34 in one circuit. Furthermore, the panel ground wire (panel grounding means) 43 that grounds the solar cell panel 1 is branched to connect the solar cell panel 1 and the negative side of the AC unit 41. Therefore, the AC unit 41 can be grounded. Therefore, the connection wiring of the solar cell system 30 is facilitated, the workability is improved, and the back electrode side potential of the solar cell is set so that the Na plus ion in the glass substrate is not easily applied to the inside of the photoelectric conversion cell. It can be set as the solar power generation system 30 using the solar cell panel 1 which suppressed the quality change and the deterioration close to the ground potential.

  Even when the capacity of the solar power generation system 30 changes due to the addition of the solar cell panel 1 or the like, the AC unit 41 is provided for each solar cell panel 1, so that the solar cell panel 1 necessary for the extension is provided. It becomes possible to respond by installing. Therefore, the expansion and individual design of the solar cell panel 1 are facilitated.

  A finned heat radiating plate (heat radiating means) 50 that is provided on the back side of the solar cell panel 1 near the AC unit 41 and radiates the heat generated by the AC unit 41 by itself is a heat radiating plate main body (heat radiating means main body). 51 and fins (protruding portions) 52 extending in a direction away from the AC unit 41. Moreover, the installation direction of the heat sink main body 51 having the fins 52 is variable. Thus, for each solar cell panel 1, the installation direction of the finned radiator plate 50 in the direction in which the air flow (airflow) flowing through the solar cell panel 1 easily flows along the extending direction of the fins 52 of the finned radiator plate 50. Can be adjusted. Therefore, the self-heating of the AC unit 41 can be effectively radiated by the finned heat sink 50 regardless of the installation form of the solar cell panel 1.

  The heat sink main body 51 is formed in a substantially triangular shape that tapers in a direction away from the AC unit 41. Thereby, the surface area of the heat sink main body 51 can be reduced in the direction away from the AC unit 41. Accordingly, the finned heat sink 50 is reduced in size, the production cost of the finned heat sink 50 is reduced, and no heat dissipating means is provided in an area where the effect of heat dissipation is low. Without hindering, the exchange of airflow is promoted and the heat radiation becomes more effective. Accordingly, it is possible to suppress the failure of the AC unit 41 and improve the reliability.

[Second Embodiment]
The present embodiment is basically the same as the first embodiment, but the first embodiment is different from the panel ground wire (panel) provided between the panel ground portions provided on the aluminum frame of each solar cell panel. Are connected to a common earth line (common grounding means) after being connected by a grounding means for the purpose, and the clock pulse is transmitted to the common earth line. Therefore, in this embodiment, this different part is demonstrated and about the adjustment of installation of another overlapping component and a finned heat sink, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

FIG. 12 shows a schematic configuration diagram of the photovoltaic power generation system of the present embodiment.
The photovoltaic power generation system 60 is a power controller to which an aluminum frame (frame) provided on the outer periphery of each solar cell panel 1 and AC power (power) converted by an AC unit (power conversion means) is guided. (External output means) 35, string ground wire (string ground means) 62 connected to each solar cell string 32, and panel ground for each solar cell panel 1 constituting each solar cell string 32 A panel ground wire (panel grounding means) 61 connecting portions (in this embodiment, an aluminum frame frame (not shown)) and a string ground wire 62 are joined together and grounded. A line (common grounding means) 63.

  Since each solar cell panel 1 constituting each solar cell string 32 has aluminum frame frames connected to each other by a panel ground wire 61, a panel grounding portion of each solar cell panel 1 (in this embodiment, aluminum). The frame frame) is electrically connected to a ground potential.

  Moreover, since the string ground wire 62 connected to each solar cell string 32 merges with the common ground wire 63 between the solar cell strings 32, the panels of each solar cell panel 1 of each solar cell string 32. Between the ground parts for electrical use, they are electrically connected to have a ground potential.

  The common ground wire 63 is joined with a connection box ground wire 64 for grounding the connection box 34. The common ground wire 63 joined with the connection box ground wire 64 joins the power controller ground wire 65 connected to the power controller 35 and is grounded.

Next, a method of synchronizing the phases when the AC unit (not shown) converts the DC power generated in each solar cell panel 1 into AC power will be described.
A clock pulse (synchronization signal) is transmitted from the power controller 35 to the common ground line 63 as indicated by an arrow. Since the power controller 35 is electrically connected to each solar cell panel 1 via the power control ground wire 65 and the common ground wire 63, the clock pulse transmitted from the power controller 35 is controlled by the power control. The ground wire 65, the common ground wire 63, the string ground wire 62, the panel ground wire 61, and the panel ground portion flow in this order and are transmitted to the AC unit provided in each solar cell panel 1.

In this way, by transmitting the clock pulse to each solar cell panel 1 using each ground wire 61, 62, 63, 65, the AC power phase is adjusted by the AC unit provided in each solar cell panel 1. It can be accurately and easily synchronized.
Further, the string ground wires 62 are not necessarily provided separately, and the panel ground wires 61 in each solar cell string 32 may be extended as they are and connected to the common ground wire 63.
Here, the synchronization of the clock pulse is guided by the power controller 35 so that the AC wave period of the power system 40 is accurately acquired from the insulating transformer 36 to the power controller 35, and the frequency period of the power system 40 is obtained. It matches.

As described above, the photovoltaic power generation system 60 according to the present embodiment has the following effects.
The common ground line (common grounding means) 63 is connected to each solar cell string 32 via a string ground line (string grounding means) 62, and each solar cell panel constituting each solar cell string 32. 1, aluminum frame frames (frames) of solar cell panels 1 are electrically connected to each other by panel ground wires (panel grounding means) 61. A clock pulse (synchronization signal) is transmitted from the power controller (external output means) 35 to the common ground line 63 of the solar cell array 33 configured as described above. Therefore, the clock pulse is transmitted to the AC unit (power conversion means) provided in each solar cell panel 1 through the common ground line 63, each string ground line 62, and each panel ground line 61. It will be. Therefore, the phase of the alternating current power of each solar cell panel 1 can be synchronized.

[Third Embodiment]
The present embodiment is basically the same as the second embodiment, but the second embodiment is that the AC unit transmits an abnormal signal and the abnormal signal is transferred to the data logger. Is different. Therefore, in this embodiment, this different part will be described, and other overlapping components, adjustment of the installation of the finned heat sink, and the synchronization method will be given the same reference numerals and redundant description will be given. Omitted.

FIG. 13 shows a schematic configuration diagram of a photovoltaic power generation system according to the present embodiment.
The photovoltaic power generation system 70 according to the present embodiment includes a data logger (recording device and monitoring device) 71 to which a part of a common ground wire (common grounding means) 63 is connected.
The data logger 71 outputs a signal specific to each AC unit (power conversion means) transmitted from the common ground line 63 and the presence / absence of an abnormality based on the abnormality signal.

  The AC unit (not shown) provided in each solar cell panel 1 includes a signal specific to each AC unit and an abnormal signal when the solar cell panel 1 including the AC unit has an abnormality. Send.

Next, a method for detecting an abnormality in each solar cell panel 1 will be described.
From the AC unit provided in the solar cell panel 1, signals unique to each AC unit are transmitted to the panel ground wire (panel grounding means) 61, the string ground wires (string grounding means) 62 and the common. The data is transferred to the data logger 71 through the ground wire 63. The string ground wire 62 may be substituted by the panel ground wire 61.

  Here, each panel ground wire 61, each string ground wire 62, and common ground wire 63 are for obtaining a common ground potential, and since no power is flowing, they can be used for signal transmission. It has become.

  When there is an abnormality in the solar cell panel 1, an abnormality signal is transmitted together with a signal specific to the AC unit from the AC unit provided in the solar cell panel 1 having the abnormality. The unique signal and the abnormal signal transmitted from the AC unit are the panel ground wire 61, each string ground wire 62 (the string ground wire 62 may be replaced by the panel ground wire 61) and common. The data is transferred to the data logger 71 through the ground wire 63. The data logger 71 outputs an alarm and records based on the transferred abnormality signal and a signal specific to each AC unit.

Since the AC unit transmits a signal unique to each AC unit together with the abnormality signal to the data logger 71, it is possible to identify the solar cell panel 1 having the abnormality.
Moreover, the power generation state (voltage, current, output power, etc.) of each solar cell panel 1 is transmitted together with the unique signal for each AC unit, thereby monitoring the power generation state of each solar cell panel 1 unit. And can be recorded.

As described above, the photovoltaic power generation system 70 according to the present embodiment has the following effects.
From each AC conversion unit (power conversion means), a unique signal is transmitted for each AC conversion unit (not shown), and when there is an abnormality in the solar cell panel 1, an abnormality signal is transmitted. A part of a common ground wire (common grounding means) 63 is connected to the data logger (recording device and tube device) 71. Thus, the unique signal and the abnormal signal transmitted from the AC unit are transmitted through the common ground wire 63, each string ground wire (string grounding means) 62, and each panel ground wire (panel grounding means) 61. It can be transferred to the data logger 71. Therefore, the common ground wire 63 through which power does not flow, each string ground wire 62, and each panel ground wire 61 can be used for signal transmission. Therefore, signal reception such as a signal unique to each AC unit or an abnormal signal in the data logger 71 is facilitated.

[Fourth Embodiment]
This embodiment is basically the same as the first embodiment, but differs from the first embodiment in that a capacitor is provided between the solar battery power generation cells of the solar battery panel. Therefore, in this embodiment, this different part is demonstrated and about the adjustment of installation of another overlapping component and a finned heat sink, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

  FIG. 14 shows a schematic vertical cross-sectional configuration diagram of a solar battery panel having a capacitor between solar battery power generation cells according to this embodiment. FIG. 15 shows an equivalent circuit of the solar cell panel shown in FIG. In FIG. 15, Rs indicates a series resistance, Rsh indicates a shunt resistance, Iph indicates a photocurrent, and Io indicates a reverse saturation current.

As shown in FIG. 14, a dielectric layer 80, which is a dielectric layer, is provided on the back electrode layer 8 of each solar battery power generation cell (cell) constituting the solar battery panel 1. The dielectric layer 80 is deposited on the back electrode layer 8 by, for example, an MO-CVD apparatus (not shown) and then corresponds to each solar cell 15 (see FIG. 4) by a laser etching apparatus (not shown). In this way, it is cut into a strip shape, or formed into a thin plate and cut into a predetermined size, and then installed in close contact with the back electrode layer 8.
A metal electrode 81 described later enters the cut position (separation groove) of the dielectric layer 80 and is electrically connected to the back electrode layer 8 of the adjacent solar battery cell 15.

  Further, a metal electrode 81 is provided so as to face the back electrode layer 8 with the dielectric layer 80 provided on the back electrode layer 8 interposed therebetween. The metal electrode 81 is provided in a strip shape so as to correspond to each solar battery power generation cell 15 by a laser etching apparatus or chemical etching by masking together with the dielectric layer 80. Here, Ti, Al, or the like is used for the back electrode layer 8 and the metal electrode 81.

  By configuring the dielectric layer 80 to be sandwiched between the back electrode layer 8 and the metal electrode 81, the capacitor 82 is provided between the solar battery power generation cells 15. For the first electrode of the capacitor 82, the back electrode layer 8 of the solar battery power generation cell 15 is used in common.

  The capacitor 82 is provided between the solar battery power generation cells 15. Each photovoltaic power generation cell 15 provided with the capacitor 82 is, for example, approximately 1.4 m × 0.01 m in size and has 100 cell stages, and each is electrically connected in series. The solar cell panel 1 is configured.

  The dielectric layer 80 is filled with polypropylene (dielectric constant ε: 2.6) as a dielectric. The dielectric layer 80 has a thickness d of, for example, about 30 μm.

Capacitance C of each capacitor 82 is about 100 μF with respect to the solar cell panel 1 with an output of 150 W, so that instantaneous fluctuation output in milliseconds (msec) can be absorbed. For example, 96 μF / cell.
Capacitor capacity C = 8.854 × 10 ⁻⁴ × (ε × S / d) = 96 μF / cell In the above formula, ε represents the dielectric constant of the dielectric, S represents the surface area of the solar cell 15, d Indicates the thickness of the dielectric layer 80.

FIG. 15 shows an equivalent circuit in which the capacitors 82 as described above are installed between the solar battery power generation cells 15.
The capacitor 82 is provided between the solar battery power generation cells 15 connected in series. Since the capacitors 82 are thus provided between the solar power generation cells 15, the solar panel 1 is partially shaded by fluctuations in solar radiation, and the power generation amount of some of the solar power generation cells 15 is reduced. Even when a sudden fluctuation occurs in the output of the solar battery panel 1 or the like, the fluctuation in the output can be absorbed (smoothed) for each solar battery power generation cell 15. Therefore, the inverter (not shown) etc. which comprise the AC conversion unit (not shown) built in the terminal box (not shown) of each solar cell panel 1 suppressing the rapid fluctuation | variation of an output, etc. The operation can be stabilized.

In addition, the withstand voltage of the small-capacitance capacitor 82 having a capacitor capacity C of 96 μF / cell is lower than the electromotive force of each solar power generation cell 15, and is therefore a low voltage of 5 V or less, for example, about 2 V. Therefore, the capacitor 82 can be easily manufactured.
Furthermore, since rapid fluctuations in the output of the solar cell panel 1 can be suppressed without using a large-capacity electrolytic capacitor, the photoelectric conversion device 5 (see FIG. 1) due to leakage of the electrolytic solution in the electrolytic capacitor or the like. No effect. Further, unlike the electrolytic capacitor, there is no need to worry about the life of the electrolytic solution, and there is no concern about the life of the capacitor 82 such as the service life of the capacitor 82.

As described above, the photovoltaic power generation system according to this embodiment has the following effects.
Capacitors 82 are provided between the solar power generation cells (cells) 15 (see FIG. 4) constituting the solar battery panel 1. Therefore, even if there is a sudden change in the output from the solar cell panel 1 due to a decrease in the amount of power generated by some of the solar cell power generation cells 15 of the solar cell panel 1, the solar cell power generation by each capacitor 82. The change in output can be absorbed (smoothed) for each cell 15. Therefore, since an AC output unit (power conversion means) provided in each solar cell panel 1 can absorb a sudden change in output, it is possible to improve the workability of the photovoltaic power generation system.

  In addition, since a small-capacitance capacitor 82 is used, the withstand voltage of the capacitor 82 can be reduced, so that manufacturing management of the capacitor 82 is facilitated. Therefore, it can be set as the solar power generation system excellent in withstand voltage.

  In this embodiment, the dielectric is described as polypropylene, but polyethylene (dielectric constant ε: 2.4), polyester (dielectric constant ε: 2.8), or the like may be used.

[Fifth Embodiment]
This embodiment is basically the same as the fourth embodiment, but differs from the fourth embodiment in that a capacitor is provided between a plurality of cells. Therefore, in this embodiment, this different part is demonstrated and about the adjustment of installation of another overlapping component and a finned heat sink, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

FIG. 16 shows an equivalent circuit of a solar battery panel having a capacitor between a plurality of solar battery power generation cells according to this embodiment.
For example, one capacitor 92 is provided for every two (plural) photovoltaic power generation cells (cells) 15 (see FIG. 4). The capacitor 92 thus provided can be easily installed by changing the position of the separation groove that separates the dielectric and the metal electrode.

  In FIG. 16, a capacitor 82 is provided between the solar power generation cells 15 in parallel with the capacitor 92 provided for each of the two solar power generation cells 15.

  As described above, since one capacitor 92 is provided for each of the two solar power generation cells 15, the capacity of the capacitor 92 can be interchanged and increased with the two solar power generation cells 15. Therefore, even if a sudden change occurs in the output of the solar cell panel, the change in the output can be absorbed (smoothed).

  In addition, the capacitor 92 provided for each of the plurality of solar battery power generation cells 15 includes at least three solar batteries in order to suppress a decrease in the performance of the solar battery due to an increase in leakage current that has passed through the dielectric. It is preferable to be provided for each power generation cell 15.

DESCRIPTION OF SYMBOLS 1 Solar cell panel 30 Solar power generation system 32 Solar cell string 33 Solar cell array 41 AC conversion unit (electric power conversion means)
43 Ground wire for panel (grounding means for panel)

Claims (10)

A solar cell array in which a plurality of solar cell strings in which a plurality of solar cell panels for generating electric power are connected are connected;
Power conversion means provided on each of the solar cell panels and converting the DC power generated by each of the solar cell panels into desired AC power, and
Each of the solar cell panels has a panel grounding means for grounding a part of the solar cell panel,
The panel grounding means is branched to connect between the solar cell panel and a negative electrode side for inputting DC power to the power conversion means. A panel grounding portion provided in each of the solar cell panels;
External output means to which AC power converted by the power conversion means is guided;
The panel grounding means connected to the panel grounding portion of each solar cell panel constituting each solar cell string;
A common grounding means for grounding via each panel grounding means,
2. The photovoltaic power generation system according to claim 1, wherein an AC output synchronization signal is transmitted from the external output unit to the power conversion unit. A recording device and a monitoring device to which a part of the common grounding means is connected;
Each of the power conversion means transmits a signal unique to each of the power conversion means and an abnormal signal when there is an abnormality in the solar cell panel having the power conversion means. The photovoltaic power generation system according to claim 2. Provided on the back side opposite to the light receiving surface of the solar cell panel for generating electric power, comprising power conversion means for converting the DC power generated by each solar cell panel into desired AC power,
On the back surface of each solar cell panel in the vicinity of the power conversion means, a heat dissipation means for dissipating the self-heating of the power conversion means is provided,
The heat dissipating means has a heat dissipating means main body, and a plurality of protrusions that protrude from the surface of the heat dissipating means main body and extend in a direction away from the power conversion means,
The solar radiation power generation system characterized in that the installation direction of the heat dissipating means body can be adjusted.   The solar power generation system according to claim 4, wherein the heat dissipating means body has a shape that tapers in a direction away from the power conversion means. Provided in each solar cell panel, comprising power conversion means for converting the DC power generated by each solar cell panel into desired AC power,
A photovoltaic power generation system, wherein a capacitor is provided between each cell constituting the solar battery panel.   Branching a panel grounding means for grounding a part of each of the solar cell panels constituting a solar cell array in which a plurality of solar cell strings in which a plurality of solar cell panels for generating electric power are connected are connected, and each of the solar cell panels The solar cell panel is connected to a negative electrode side that inputs the DC power to power conversion means that converts the DC power generated by each solar cell panel into desired AC power. The grounding method of the photovoltaic power generation panel.   Provided in each solar cell panel constituting a solar cell array in which a plurality of solar cell strings in which a plurality of solar cell panels for generating electric power are connected are connected, and the DC power generated by each solar cell panel is converted into desired AC power Panel grounding means for grounding a part of each of the solar cell panels with a specific signal from the power conversion means for converting and an abnormal signal transmitted when there is an abnormality in the solar cell panel having the power conversion means; A monitoring method using a photovoltaic power generation system, wherein monitoring is performed by a recording device and a monitoring device connected to a common grounding means for grounding via the panel grounding means. Each of the suns in the vicinity of the power conversion means provided on the back side opposite to the light receiving surface of the plurality of solar cell panels for generating electric power and converting the DC power generated by each solar cell panel into desired AC power A heat dissipating means main body of the heat dissipating means for dissipating the self-heating of the power conversion means on the back surface of the battery panel, and a plurality of protrusions projecting from the surface of the heat dissipating means main body and extending away from the power conversion means. Protruding part of
The cooling method of the power conversion means characterized by adjusting the installation direction of the said heat radiating means main body for every installation direction of the said solar cell panel. Provided in each of a plurality of solar cell panels, provided with a capacitor between each cell of the solar cell panel provided with power conversion means for converting DC power generated by each solar cell panel into desired AC power, A method for leveling generated power of a solar cell panel, wherein the power generated by the solar cell panel is leveled.

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