Photovoltaic power generating apparatus, method of producing same and photovoltaic power generating

专利摘要:
PURPOSE: A photovoltaic power generating apparatus, a method of producing the same, and a photovoltaic power generating system are provided to reduce costs and influences of partial shadows. CONSTITUTION: A photovoltaic power generating apparatus comprises a single solar battery cell(1) formed on a substrate; and a plurality of power converters individually connected to the solar battery cell so as to convert an output from the solar battery cell. The power converters are DC-DC converters(2) for boosting DC voltages output from the solar battery cell.
公开号:KR20040045387A
申请号:KR1020030083988
申请日:2003-11-25
公开日:2004-06-01
发明作者:토요무라후미타카；미무라토시히코
申请人:캐논 가부시끼가이샤；
IPC主号:

专利说明:

Photovoltaic device, manufacturing method and photovoltaic system {PHOTOVOLTAIC POWER GENERATING APPARATUS, METHOD OF PRODUCING SAME AND PHOTOVOLTAIC POWER GENERATING SYSTEM}
[48] Background of the Invention
[49] Field of invention
[50] The present invention relates to a photovoltaic device, a photovoltaic system and a method for manufacturing the photovoltaic device.
[51] Related Background
[52] Recently, due to the release of carbon dioxide, for example, accidents in nuclear facilities and nuclear waste, due to radioactive pollution and the use of fossil fuels, serious problems such as global warming have emerged, and interest in the environment and energy of the earth has increased. have. Under these circumstances, photovoltaic power generation using solar radiation, geothermal power generation using geothermal power, and wind power generation using wind power, etc., have been put to practical use worldwide as an infinite and clean energy source.
[53] Among these energy sources, there are various forms of photovoltaic power generation using solar cells depending on the output range of several W to several thousand KW. A typical system using solar cells converts DC power generated by solar cells into AC power (DC-AC conversion) by an inverter or the like and converts the generated power into a consumer or commercial power system load (hereinafter referred to as a "system"). It is a photovoltaic power generation system to supply.
[54] 2 is a schematic configuration diagram of a conventional general photovoltaic system. As shown in the figure, the photovoltaic power generation system 8 generally uses a solar cell module 6 composed of a plurality of solar cells connected in series as a unit, and includes a plurality of solar cell modules connected in series ( Forming a solar cell stringing 7 (also referred to as a "solar cell array") consisting of 6), and also forming a solar cell array consisting of a plurality of these solar cell strings 7 connected in parallel, The DC outputted from the solar cell array is collected by the current collector box 9, the collected power is converted into AC power by the inverter 3, and the AC power is transferred to the load 4 or the commercial system 5 from each other. Connect it.
[55] In such a photovoltaic system 8, when the outputs of the plurality of solar cell strings 7 are changed from one string to another due to a change in the output characteristics of the solar cell or a partial shadow of a building, The solar power generation system 8 may not be able to operate at the optimum power generation point.
[56] In order to cope with such a problem, Japanese Patent Laid-Open No. 2000-112545 has a DC-DC converter installed in each solar cell array via a connection box, and the DC output power is inputted to the inverter at the same time. A photovoltaic power generation system for converting electric power into AC power is disclosed. In the above arrangement, each DC-DC converter performs the optimum power point tracking control on the connected solar cell array, thereby improving the accuracy of the optimum power point tracking control for the photovoltaic system.
[57] In addition, Japanese Patent Application Laid-Open No. H 08-70533 includes an inverter for each solar cell array, solar cell module, or solar cell, and changes in output between the solar cell array, solar cell module, or solar cell. In addition, the present invention discloses the possibility of increasing or decreasing the amount of power generated by the solar cells at the lowest cost by installing an inverter for each solar cell module or solar cell while reducing the difference in power efficiency due to the partial shadow. have.
[58] However, in the photovoltaic power generation system disclosed in Japanese Patent Laid-Open No. 2000-112545, which inputs the DC output of a solar cell array or a solar cell module to a DC-DC converter, a plurality of solar cells are connected in series. There is a need to manufacture a battery cell module.
[59] In general, a cutting process of dividing a photovoltaic layer stacked on a substrate into solar cells, an end etching process for forming a non-power generation region that insulates between one solar cell and another, and interconnection such as an interconnector The process of connecting the solar cells in series by using a member, connecting the bypass diodes in order to reduce the effect of partial shadows, coating the group of series connected solar cells, and applying the solar cell In order to manufacture a solar cell module, such as a process of fixing a frame to an end, a very large number of steps are required, and at the same time, the cost of each member used is high, which increases the cost of the photovoltaic device. .
[60] In particular, when manufacturing a solar cell module having a large area, the process of connecting a plurality of solar cells in series takes time and has a problem, a serious problem occurs in the production of a solar cell module having a large area. .
[61] In addition, the configuration of a plurality of solar cells connected in series using a wiring member such as an inter-connector requires a gap for inserting inter-connectors between the solar cells, and the number of caps is connected in series. As the number of photovoltaic cells increased, the number of non-generated regions not used for power generation is increased in the solar cell module.
[62] In addition, since the solar cells are connected in series, the influence of the partial shadow on power generation efficiency also increases. For example, if one of the solar cells connected in series is covered by the partial shadow, the current generated from the cell is reduced and the ratio of current generated from the other cell is also limited by the cell.
[63] In order to reduce the influence on the partial shadow, a bypass diode connected in parallel to each of the solar cells connected in series is required. However, even when the above method is used, the effect of the partial shadow on other power generation cells cannot be completely eliminated.
[64] Further, as disclosed in Japanese Patent Application Laid-Open No. H08-70533, the provision of an inverter for each solar cell can alleviate the work of the series connection process, which is the problem described above, but when manufacturing these solar cells, the solar cells are individually. The cutting and etching process at the end of the cell is still time consuming and problematic.
[65] In addition, in the case of using a structure in which solar cells are installed on a support, in order to improve electrical insulation, appearance, and area power generation efficiency between each solar cell, it is necessary to accurately install these solar cells at regular intervals. However, this work is difficult and causes a cost increase.
[66] In US Pat. No. 4,773,944, all of the above-mentioned problems, such as a multiple step of serial connection, an increase in cost, the influence of partial shadows, and the difficulty of installation work, are individually formed on a single substrate, and all are connected in parallel. Disclosed is a solar cell module consisting of individual solar cell.
[67] These solar cell modules are configured in such a manner that a current collecting bus bar is connected to a current collecting electrode of each solar cell and the outputs of the plurality of solar cells are collected at a single output.
[68] However, in these configurations, the value of the current flowing through the current collecting busbar is the sum of the output currents of the plurality of solar cells, so that the number of solar cells increases and the area of the solar cell module increases, resulting in loss of current collection. It also leads to other problems that increase markedly.
[69] In order to solve the problem of current collecting loss, the cross-sectional area of the current collecting bus bar is increased, but this solution significantly increases the weight and volume of the current collecting bus bar, making manufacturing / transporting work difficult.
[70] Summary of the Invention
[71] The present invention is realized in view of the above-described situation, and an object of the present invention is to provide a photovoltaic device having a simple configuration capable of reducing manufacturing costs and reducing the influence of partial shadows and changes in their characteristics, and photovoltaic power generation. Provided are a photovoltaic power generation system using the device and a method of manufacturing the photovoltaic device.
[72] The present invention is configured as follows.
[73] That is, the first aspect of the present invention is a photovoltaic device comprising a single solar cell formed on a substrate and a plurality of power converters individually connected to the solar cell for converting the output of the solar cell.
[74] The plurality of power converters are preferably DC-DC converters for boosting the DC voltage output from the solar cell.
[75] In addition, the plurality of power converters are preferably inverters.
[76] In addition, the wiring member for electrically connecting the solar cell and the power converter preferably has a live section exposed at least in part.
[77] In addition, in the photovoltaic cell consisting of a photoelectric conversion layer, a current collecting electrode disposed on the light receiving portion side of the photoelectric conversion layer, a surface wiring member and a projection thin film resin layer,
[78] At least a part of the current collecting electrode or the surface wiring member preferably has an exposed portion not covered by the transparent thin film resin layer.
[79] In addition, the photoelectric conversion layer preferably includes thin film silicon.
[80] In addition, it is preferable that the substrate is conductive and the substrate side of the photoelectric conversion layer is composed of a positive electrode.
[81] Further, it is preferable that the substrate is conductive and one of the output of the solar cell and one of the output of the DC-DC converter are electrically connected to the substrate.
[82] In addition, it is preferable that one of the output of the solar cell and one of the output of the DC-DC converter is on the low voltage side.
[83] It is also preferable that one of the outputs of the solar cell and one of the outputs of the DC-DC converter are on the high voltage side.
[84] In addition, the solar cell preferably has a portion in which the power generation unit is not formed on the two outer peripheral side.
[85] In addition, the solar cell is preferably fixed to the support through a portion where the power generation unit is not formed.
[86] In addition, the solar cell or the photovoltaic device itself is preferably sealed by a resin.
[87] In addition, the solar cell is preferably the lowest power generation unit having a function as a solar cell.
[88] In addition, in the photovoltaic power generation system which is also composed of a plurality of current collecting electrodes for collecting the respective power of the solar cell,
[89] Each of the plurality of integrated electrodes is connected to one of the plurality of power converters so that the power individually collected by the plurality of current collectors is individually converted.
[90] The second aspect of the present invention,
[91] A photovoltaic device comprising a single solar cell formed on a substrate and a plurality of DC-DC converters converting the DC output of the solar cell and individually connected to the solar cell;
[92] A photovoltaic power generation system including an inverter that converts outputs of a plurality of DC-DC converters into AC power and supplies AC power to a load or interconnects AC power to commercial power.
[93] The inverter has a wiring member for connecting the insulated transformer and the DC-DC converter, and is preferably grounded.
[94] A third aspect of the invention includes a photovoltaic device comprising a single solar cell formed on a substrate and a plurality of inverters individually connected to the solar cell for converting the output of the solar cell into AC power. In photovoltaic power generation system,
[95] The plurality of inverters are photovoltaic power generation systems that supply output power to a load or interconnect output power to a commercial power system.
[96] According to a fourth aspect of the present invention, in the method for manufacturing a photovoltaic device,
[97] Forming a solar cell on a substrate through a semiconductor manufacturing process;
[98] A method of manufacturing a photovoltaic device comprising a step of connecting a plurality of power converters to a predetermined portion of a solar cell.
[99] It is preferable to form a solar cell by continuously forming a photoelectric conversion layer, a collecting electrode and a surface wiring member on a substrate, and to connect a power converter to a predetermined portion of the solar cell continuously.
[100] According to the present invention, a photovoltaic device using only one solar cell formed on a substrate can be configured. For this reason, in the case of a solar cell module of a type which requires a cutting process, an end etching process, a series connection process and a bypass wired connection process, etc. for the manufacture of a solar cell module, a cutting process, an end etching The step, serial connection step and bypass diode connection step are unnecessary. This fact reduces manufacturing and material costs. In addition, since the non-power generation area not used for power generation is reduced, the efficiency of the power generation area of the photovoltaic device is significantly improved.
[101] In addition, it is not necessary to install a plurality of solar cells at regular intervals on the support, and the time required to install the photovoltaic device by installing the photovoltaic device having the solar cells in a wider area as a unit. Can be greatly shortened and the cost required for installation can be reduced.
[102] In addition, since the influence of the partial shadow is limited only to the power converter contained in the shadow area, it has no influence on other power converters. In addition, since only one solar electronic element is formed on the substrate, the variation of the electrical characteristics of the solar cell in the photovoltaic device is also small. Therefore, compared to the conventional system having a plurality of solar cells connected in series, the influence of the partial shadow and the variation of the characteristics can be made very small.
[103] Therefore, for example, one large-length solar cell having a large area can be used and a photovoltaic device using the same can be constructed. This reduces manufacturing and material costs by eliminating the need for a cutting process, end etching process, series connection process, bypass diode connection process, and the like, which are conventionally required for manufacturing a solar cell module. It also improves the efficiency of the power generation area of the photovoltaic device.
[104] Since the photovoltaic device is composed of only one solar cell on a substrate, a semiconductor layer, an electrode layer, or the like can be obtained on one conductive substrate by continuous film formation. This can significantly reduce the variation of characteristics and the effect of partial shadows compared to conventional systems having solar cells connected in series.
[105] In addition, by significantly reducing current collection losses, the cross-sectional area of the member-connected DC-DC converter in parallel is significantly reduced, the material cost is significantly reduced, the weight is reduced, and the ease of installation is improved.
[106] Other features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings.
[1] 1 is a schematic diagram showing the configuration of a photovoltaic power generation system according to a first embodiment of the present invention.
[2] 2 is a diagram showing a schematic configuration of a conventional general photovoltaic system.
[3] 3 is a cross-sectional view illustrating a configuration example of the solar cell of FIG. 1.
[4] 4 is a diagram illustrating a schematic configuration of the solar cell of FIG. 1.
[5] FIG. 5 is a diagram illustrating a process of manufacturing the solar cell of FIG. 1. FIG.
[6] 6 is an external view showing an outline of a photovoltaic power generation system according to a first embodiment of the present invention.
[7] 7 is a circuit diagram showing an example of a DC-DC converter.
[8] 8 is a circuit diagram illustrating an example of an inverter.
[9] 9 illustrates a PWM control system of an inverter according to the present invention.
[10] 10 is an external view showing an outline of a photovoltaic power generation system according to a second embodiment of the present invention.
[11] FIG. 11 is a circuit diagram showing a schematic configuration of the photovoltaic system of FIG. 10. FIG.
[12] FIG. 12 is an enlarged view showing a connection portion between an individual solar cell of FIG. 10 and a DC-DC converter; FIG.
[13] FIG. 13 is a circuit diagram showing a connection between a main circuit of the DC-DC converter of FIG. 10 and a conductive substrate of a solar cell.
[14] 14 is a view for explaining the installation method of the photovoltaic power generation system of FIG.
[15] FIG. 15 is a diagram showing a schematic configuration of an inverter of a high frequency link method used in the photovoltaic power generation system of FIG. 10; FIG.
[16] FIG. 16 shows a potential-pH diagram of copper. FIG.
[17] 17 is an external view showing an outline of a photovoltaic power generation system according to a third embodiment of the present invention.
[18] FIG. 18 is a circuit diagram showing a schematic configuration of the photovoltaic system of FIG. 17. FIG.
[19] FIG. 19 is a circuit diagram showing a connection between a main circuit of the DC-DC converter of FIG. 17 and a conductive substrate of a solar cell. FIG.
[20] 20 is an external view showing an outline of a photovoltaic device according to a fourth embodiment of the present invention.
[21] 21 is an external view showing an outline of a photovoltaic power generation system according to a fifth embodiment of the present invention.
[22] FIG. 22 is a cross sectional view along line 22-22 in FIG. 21;
[23] <Detailed Description of Symbols in Drawings>
[24] 1: solar cell 2, 2004: DC-DC converter
[25] 3: inverter 4: load
[26] 5: Commerce Industry 6: Solar Cell Module
[27] 7: solar cell stringing 8: solar power system
[28] 9: current collector box 10: conductive substrate
[29] 11: lower electrode layer 12: semiconductor layer
[30] 13: upper electrode layer 14: etching electrode
[31] 16: light receiving surface terminal member 23: transparent thin film resin layer
[32] 25: insulating double-sided adhesive tape 29, 30: MOSFET
[33] 35: control power supply generation circuit 36: reference waveform generation circuit
[34] 37: MOSFET driver 38: Input terminal
[35] 39: smoothing capacitors 40a, 40b, 40c, 40d: transistors
[36] 41: full bridge circuit 42: coil
[37] 43: Capacitor 46: Band Pass Filter
[38] 47: output current detector 49: DC voltage reference voltage source
[39] 50: multiplier 51: output current control error amplifier
[40] 52: PWM modulation circuit 53: gate driving circuit
[41] 62: copper band 130: mounting portion
[42] 106: photovoltaic device 115: etching line
[43] 401, 501: solar cell assembly 2001: photovoltaic device
[44] 2002: solar cell cell 2005: light receiving surface terminal member
[45] 2006: Weatherable film 2007: Filler
[46] 2008: Lee, Jaejae2009: Light-Receiving Terminal
[47] 2010: double sided adhesive tape
[107] <Description of the Preferred Embodiment>
[108] Hereinafter, an embodiment of a photovoltaic device and a photovoltaic system according to the present invention will be described in detail with reference to the accompanying drawings.
[109] (First embodiment)
[110] 1 is a schematic diagram showing the configuration of a photovoltaic power generation system according to a first embodiment of the present invention. (1) shows one solar cell formed on a conductive substrate, (2) shows a DC-DC converter, (3) shows an inverter, (4) shows a load, and (5) The commercial system is shown.
[111] The term "solar cell" used below refers to a minimum unit having a function as a solar cell capable of drawing power. For example, when a power generation region is divided by an etching line, a solar cell refers to a constant region having a photovoltaic layer divided by an etching line or the like, and has a minimum function as a solar cell capable of drawing power therefrom. Refers to the unit. The solar cell is not limited to having one photoelectric conversion device, and may also have a plurality of photoelectric conversion layers stacked on each other. Examples of a solar cell having a plurality of stacked photoelectric conversion layers include a series structure and the like, and a stack of a plurality of photoelectric conversion layers having different spectral sensitivities is a solar cell capable of drawing power and has a minimum power generation unit. Configure.
[112] Here, the DC power output from the solar cell is formed in the solar cell at predetermined intervals, and the voltage is boosted at a predetermined step-up ratio, and these outputs are all input together to the inverter 3, and the AC power at the commercial frequency. The power is supplied to the load 4 and the excess power is transmitted to the commercial system 5.
[113] Hereinafter, a device consisting of a plurality of DC-DC converters 2 and solar cells 1 connected to a solar cell is referred to as a "photovoltaic device 106".
[114] Hereinafter, the components used in the photovoltaic device and the photovoltaic system according to the embodiment will be described in detail.
[115] (Solar cell)
[116] FIG. 3 is a cross-sectional view showing the laminated structure of the solar cell element 1 formed on the conductive substrate, and is composed of the lower electrode layer 11, the semiconductor layer 12, and the upper electrode layer 13 stacked on the conductive substrate 10. As shown in FIG. . The lower electrode layer 11 may be omitted depending on the structure of the conductive substrate 10.
[117] Here, as the conductive substrate 10, a substrate which is pre-wound in a roll shape is preferable, and the roll-to-roll method is obtained by laminating the above-described layers while sequentially feeding the substrate and rewinding it at the other end. It is preferable to manufacture a conductive substrate by a continuous film forming method such as) from the viewpoint of productivity, and the case where the method is used will be mainly described below. Of course, a batch system device can also be used.
[118] The lower electrode layer 11, the semiconductor layer 12, and the upper electrode layer 13 are disclosed in detail in Japanese Patent Laid-Open No. 11-186572 by the applicant of the present application. Since these components are not an essential part of the present invention, detailed descriptions are omitted.
[119] As the semiconductor layer 12, thin film silicon is preferable, amorphous silicon is particularly preferable, and when amorphous silicon is used as the semiconductor layer, n-type semiconductors, i-type semiconductors, and p-type semiconductors are sequentially turned from the conductive substrate 10 side. Stacked pin junctions are commonly used.
[120] It is also preferable to use a double or triple structure in which two or three layers of the above-described pin junction or pn junction are laminated.
[121] In this embodiment, it is also preferable to use a nip junction composed of p-type semiconductors, i-type semiconductors, and n-type semiconductors stacked from the conductive substrate 10 side in some cases.
[122] As the film forming method of each layer, a vapor deposition method, sputtering method, high frequency plasma CVD method, microplasma CVD method, ECR method, thermal CVD method, LPCVD method and the like can be appropriately selected from various known and common methods.
[123] Next, in order to cut and divide the solar cell laminate formed by the above method into a desired length, an etching paste containing FeCl ₃ , AlCl ₃ , or the like is formed between the conductive substrate and the upper electrode manufactured by the division / cutting. By applying the screen printing method to the upper electrode side so that the short circuit does not affect the effective light receiving range, and heating the etching paste and then cleaning, a part of the upper electrode layer of the solar cell laminate is removed in a linear shape, FIG. 4. An etching line 115 is formed as shown in FIG.
[124] Next, as shown in Fig. 4, the insulating double-sided adhesive tape 25 is continuously festated on one side of the light-receiving surface of the conductive substrate, and the current collecting electrodes 14 are fixed at predetermined intervals with the upper electrode and the insulating double-sided adhesive body. It is formed on the tape 25. Further, the light receiving surface terminal member 16 is attached to the upper portion of the insulating double-sided adhesive tape 25 by heating / pressing bonding. The current collecting electrode 14 used here will be described later in detail.
[125] In the above-described process, as shown in FIG. 4, the solar cell assembly 401 formed by the current collecting electrode 14 and the light receiving surface terminal member 16 is manufactured.
[126] Next, as shown in FIG. 5, the transparent thin film resin layer 23 is laminated on the light receiving surface of the solar cell assembly 401 to form a solar cell assembly 501. Here, it is referred to as a solar cell assembly in the present specification regardless of the presence of the transparent thin film resin layer (23). In addition, as will be described later, this is referred to as a "solar cell" with or without a transparent thin film resin layer. The structure and the formation method of the said transparent thin film layer are demonstrated in detail later.
[127] When the transparent thin film resin layer 23 is formed, the solar cell assembly 501 may be formed by forming the transparent thin film resin layer 23 on the entire light receiving surface and a part thereof. This configuration eliminates the need for extra insulation material, reducing the cost of the photovoltaic device and the overall system.
[128] More specifically, instead of forming the transparent thin film resin layer 23 on the entire surface of the solar cell assembly 401, the projection thin film layer 23 is coated only on the minimum necessary portion to affect the power generation performance in the outdoor environment. Do not disturb. That is, without forming the transparent thin film resin layer 23 on the light receiving side terminal member 16 or the etching line 115, only a portion (active region) having photoelectric conversion characteristics is applied to at least incident light of the solar cell. Can be.
[129] Next, the solar cell assembly 501 having the above-described transparent thin film resin layer 23 stacked thereon is cut along the above-described etching line 115 to a desired length to form the solar cell 1. In addition, by arranging and electrically connecting the plurality of DC-DC converters 2 described later at predetermined intervals in the solar cell 1, the photovoltaic device 106 is shown as shown in FIG. Can be configured. In this case, the solar cell assembly 501 may be cut after connecting the DC-DC converters 2 to each other.
[130] By the configuration of the photovoltaic device, by removing the etching line separating the photoelectric conversion layer between the DC-DC converter, it has the effect of increasing the area of the active region and the efficiency of the area conversion of the solar cell. . That is, the solar cell is formed by one lowest unit having a function as a solar cell capable of drawing power from the photovoltaic layer.
[131] In the following step, the solar cell 1 is sealed with a weatherproof film, a filler, a back reinforcing material, and the like in the following steps, and protected from the outdoor environment, and the solar cell in the above configuration is also in the present invention. Similarly can be used.
[132] Next, the components of the solar cell 1 of the present embodiment will be described in detail below.
[133] (Conductive Board)
[134] The conductive substrate 10 used in the solar cell according to this embodiment is a member that mechanically supports the semiconductor layer against photoelectric conversion and is also used as an electrode on the non-light-receiving side of the solar cell. Such a substrate is preferably used as a heat resistant substrate capable of withstanding a heating temperature in the case of forming a semiconductor layer.
[135] In addition, since the conductive substrate becomes an adherend when the solar cell is adhered to a support such as a concrete block, it is preferable to use a material having good adhesion by the adhesive used.
[136] In addition, when the conductive substrate is fixed to the support using a fixing member, the conductive substrate preferably has mechanical strength, weather resistance, and corrosion resistance that withstand the fixing.
[137] As the material of the conductive substrate, for example, metals such as Fe, Ni, Cr, Al, Mo, Au, Nb, Ta, V, Ti, Pt and Pb or alloys of these metals, for example, brass and stainless steel Such as thin sheets or composites thereof, carbon sheets, galvanized steel plates, and the like.
[138] As the substrate, an electrically insulating material may be used, and a heat-resistant synthetic resin film or sheet such as polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, and epoxy Alternatively, they may be used by depositing or laminating dissimilar metal thin films on the surfaces of glass fibers, carbon fibers, boron fibers, composites of metal fibers, and their thin plates and resin sheets.
[139] Current collector electrode
[140] In general, the current collecting electrode 14 is formed in a comb shape in the upper electrode layer and the semiconductor layer of the solar cell, and determines the appropriate width or pitch from the value of the sheet resistance of the semiconductor layer or the upper electrode layer.
[141] In addition, the contact electrode requires low resistance and does not constitute a series resistance of the solar cell, and the non-constant value is preferably 10 ⁻² cm to 10 ⁻⁶ cm. As the material of the current collecting electrode, for example, Ti, Cr, Mo, W, Al, Ag, Ni, Cu, Sn or Pt or an alloy of these metals or a metal wire coated with a lead or conductive adhesive on the surface is used. . Generally, metal pastes in which the metal powder and the polymer resin binder are in the form of pests are used, but the material is not limited thereto.
[142] (Terminal member)
[143] The terminal member 16 is a member electrically connected to the current collecting electrode 14 to form a positive or negative drawing electrode. The terminal member 16 is attached to the etched surface from which the upper electrode layer of the conductive substrate or the solar cell is removed using laser welding, a conductive adhesive, soldering, or the like so as to form an electrical low resistance and mechanically firmly attached thereto. Alternatively, the terminal member 16 is attached to the current collecting electrode by pressing. The present specification distinguishes between the "light-receiving surface terminal member" and the "non-light-receiving surface terminal member" according to the position of the solar cell to which the terminal member is attached.
[144] The electrical performance and material required for the terminal member are almost the same as those of the current collector electrode described above, but it is preferable that the terminal member has a flake shape to maintain the flatness of the solar cell and have low resistance.
[145] The non-light-receiving surface terminal member may be diffused in a comb shape or radially to the entire non-light-receiving surface to improve current collection efficiency.
[146] In addition, when a terminal member for connecting to a DC-DC converter or an inverter is required, the terminal member is attached to the light receiving surface terminal member or the non-light receiving surface terminal member by using a laser welding method, a conductive adhesive, or soldering.
[147] (Projection thin film layer)
[148] In the present embodiment, the transparent thin film resin layer 23 positioned on the light receiving surface of the solar cell is at least transparent and is not particularly limited to the resin layer, provided that the lower current collector electrode, the upper electrode, and the like are protected. However, the transparent thin resin layer preferably has excellent coating property, weather resistance, and adhesiveness, and needs to be particularly excellent in water resistance.
[149] As a specific material, fluororesin, acrylic resin, polyester, polycarbonate, or the like can be used. More specifically, polyvinylidene fluoride (PVDF) resin, polyvinyl fluoride (PVF) resin, or tetrafluorethylene-ethylene copolymer (ETFE) resin can be used. The polyvinylidene fluoride resin is excellent in terms of weather resistance, but the tetrafluoroethylene-ethylene copolymer is excellent in terms of compatibility and transparency of weather resistance and mechanical strength. In addition, in order to further reduce the cost, use of a non-film material such as an acrylic resin or a fluororesin transparent paint is preferable. In this case, a coding method such as curtain coating used for conventional coating is used.
[150] From the requirements of the manufacturing process, it is preferable to use a paint having a low viscosity of less than 0.3 Pa · s as the resin coating material in which the curtain coating method can be used. In addition, from the viewpoint of improving higher productivity, the spray coating method is preferable, and in this case, a resin coating material having a low viscosity of less than 0.05 Pa · s is preferable.
[151] As the lower limit of the viscosity, there is no particular limitation, and any appropriate viscosity can be selected based on the desired film thickness. However, as the viscosity decreases, since a plurality of coatings are required to form the required film thickness, it is actually desirable to have a viscosity of 0.001 Pa · s or more.
[152] Regarding the thickness of the transparent thin film resin layer 23, the thickness that can be applied without pinholes is preferably 1 μm or more, and preferably less than about 200 μm from the following viewpoints.
[153] From the viewpoint of coating and protecting the current collecting electrode, the upper electrode or the photovoltaic layer by the transparent thin film resin layer, a thicker one is preferable. However, as the thickness increases, the sunlight passing through the transparent thin film layer is lowered, which worsens the power generation performance. In addition, the flexibility of the resin layer can be deteriorated by forming a thick layer. In addition, as the thickness increases, the current collecting electrode, the upper electrode layer, or the photovoltaic layer may be destroyed by shrinkage during curing, and when the resin layer is thicker than 200 μm when used outdoors, it is applied during thermal expansion or installation. The force can no longer be followed, the resin layer may be stressed, and cracks may occur, and peel off at the interface with the current collecting electrode, the upper electrode layer, or the photovoltaic layer.
[154] However, the transparent thin resin layer does not necessarily need to be formed of only one type of material, and for example, may constitute two layers formed using two types of materials. In this case, a material having good adhesion with the upper electrode layer can be selected just above the upper electrode layer of the solar cell, and a material having excellent weather resistance can be selected thereon. In this case, a typical forming method can be performed twice in the coating process.
[155] (Parallel connection member)
[156] The configuration of the photovoltaic device in this embodiment requires parallel connection between the DC-DC converters 2 connected to the solar cells individually. The member used for making these connections is a parallel connection member. When a conductive substrate is used as one common terminal in a solar cell, this member is used only for one electrode.
[157] More specifically, this is a member connected to one output terminal of the individual DC-DC converter 2, and an example of the example used in the present embodiment may be used as well as insulated electrode wiring or insulated cable for general use. For example, bare conductive witr without insulation coating or the like may be used. As the non-conductive wiring, a copper wiring, a spiral copper wiring or a copper band is preferable as the non-conductive wiring.
[158] (Device connection member)
[159] In this embodiment, the connecting member between the DC-DC converter 2 and the inverter 3 is defined as an inter-device connecting member. As the inter-device connection member, the same shape and material as the above-described parallel connection member can be used. The parallel connection member used for the connection between the DC-DC converters can be extended to connect to the inverter, and can be used as an inter-device connection member.
[160] (Support)
[161] The support refers to a member for fixing the solar cell, and is generally a member for forming a frame or mounting surface.
[162] The means for fixing the solar cell to the support is not limited, but the fixing method using the adhesive is preferable because it requires only a small area among the non-power generation regions of the solar cell. In addition, a non-power generation area for installation is provided in a part of the solar cell, and the part is fixed by using fixing members such as nails, screws, and bolts.
[163] In order to simplify the structure and facilitate the installation work, it is preferable to use a concrete material in this embodiment. This is because if the support is a material having a large weight such as concrete, the support is simply installed to complete the arrangement of the support. In addition, the concrete is convenient to use as a frame of the solar cell because it has excellent outdoor durability and low cost.
[164] Furthermore, for example, it is preferable to form a support by separately dividing a fixed support (support) that is a flat plate for solar cell fixing and a back support for providing the fixed support. This is convenient because the installation angle of the solar cell can be arbitrarily changed by providing a back support having a cuboid shape and the like, and arranging a fixed support having a flat shape on the back support.
[165] Next, the DC-DC converter and the inverter of this embodiment will be described in detail below.
[166] (DC-DC converter)
[167] The DC-DC converter connected to the solar cell controls a voltage boosting circuit for boosting the DC voltage to the input voltage of the inverter circuit, starting / stopping power conversion, optimizing the operating point of the solar cell, operating mode, and the like. Circuit, a grid connection protection circuit, a communication circuit, an input terminal, and the like, and its output can be directly connected to a load. However, multiple outputs of solar cells are generally input to one inverter, and the converted AC power is used for load or interconnection.
[168] As the voltage boosting circuit, various publicly known circuit configurations can be used regardless of insulation. For example, the control circuit includes a CPU, a PWM waveform control circuit, a maximum power point tracking control circuit, a control power generation circuit, a frequency / voltage reference generator, a switching control circuit, and the like. In addition, the control circuit may be operated from the outside through a communication cable or the like, or a part of the control circuit may be arranged outside the DC-DC converter to control all of the plurality of power converters together.
[169] However, in order to make the structure as simple as possible, the present embodiment reduces the cost and improves the reliability of the DC-DC converter, and the control circuit generates at least a control power supply generation circuit and a switching reference waveform generation specifying the switching frequency. It consists of a switching element driving circuit which can drive the switching element in the circuit and the fixed head.
[170] In addition, the main circuit preferably comprises a switching element which is turned on / off by the switching element driving circuit described above and a switching transformer which is manufactured at a predetermined turn ratio.
[171] In a system in which a plurality of DC-DC converters for driving switching elements in the above-mentioned fixed heads are connected in parallel, an embodiment is provided by changing the input voltage of the DC-DC converter by changing the input voltage of the inverter in the following steps. The operating point of the battery cell can be moved.
[172] In addition, a series of operations for connecting a DC-DC converter to a solar cell can be simplified by making one chip of the DC-DC converter and electrically connecting the surface wiring member and the conductive substrate in the manufacturing process of the solar cell. Can be.
[173] In order to efficiently input the output from the solar cell, the DC-DC converter is preferably disposed close to the solar cell so as to reduce the wiring loss, and is preferably attached directly to the solar cell.
[174] In addition, the exterior material of the DC-DC converter needs to have performances such as heat resistance, moisture resistance, water resistance, electrical insulation, cold resistance, oil resistance, weather resistance, impact resistance, and water resistance. In addition, in order to fix firmly to the solar cell or the back reinforcement material, it is preferable that the adhesive material with the adhesive is made of a good material.
[175] In view of the factors described above, the exterior material is a resin, i.e. polycarbonate, polyamide, polyacetel, modified PPO (PPE), polyester, polyallylate, unsaturated polyester, phenolic resin, epoxy resin, polybutylene terephthal It is composed of plastics such as eight resins and nylon, and engineer plastics. In addition, thermoplastic resins such as ABS resin, polypropylene, and polyvinyl chloride may be used.
[176] In addition, it is preferable that a DC-DC converter is attached to the light-receiving side, and carbon black is used as the pigment or a resin coating material that absorbs UV rays is applied to the light-receiving surface to improve ultraviolet light resistance.
[177] (inverter)
[178] In general, an inverter used in a solar power system includes a voltage boosting circuit for boosting an input DC voltage to an input voltage of an inverter circuit, an inverter circuit for converting DC power to AC power, starting / stopping power conversion, and It consists of control circuits, communication circuits, and input / output terminals for optimizing the operating point and operating mode, etc., and its output is used for load or interconnection.
[179] As a voltage boosting circuit, various well-known circuit systems can be used regardless of insulation or non-insulation. As the inverter circuit, a voltage inverter using an IGBT or a MOSFET as the switching element is preferable. By driving the gate of the switching element through the control signal of the control circuit, AC power having a desired frequency, phase and voltage can be obtained.
[180] The control circuit is formed by, for example, a CPU, a PWM waveform control circuit, a frequency / voltage reference generator, a maximum power point tracking control circuit, a current reference generator, a mode switch and a switching control circuit. In addition, when a plurality of inverters of the present embodiment are connected to one solar cell, the control circuit may be operated from the outside side through a communication wiring or the like, and the control circuit itself is centrally arranged outside the inverter, You can control the interleaver collectively.
[181] When the inverter of the present embodiment is electrically connected to the solar cell, the inverter is preferably arranged in close proximity to the solar cell in order to efficiently input the output from the solar cell, and is preferably connected directly to the solar cell.
[182] In addition, there are two types of inverter 3 having an insulating transformer or an inverter 3 having no insulating transformer, and any type can be used depending on the application. When the inter-device connecting member is grounded between the DC-DC converter and the inverter, an inverter with an insulated transformer is used.
[183] The inverter needs to have performances such as heat resistance, moisture resistance, water resistance, electrical insulation, cold resistance, oil resistance, weather resistance, impact resistance, and water resistance, depending on its operating conditions. It is preferable that the inverter is made of a material having an adhesive with good adhesion in order to be firmly fixed to the solar cell.
[184] In consideration of the above-described elements, the exterior material is a resin, i.e., polycarbonate, polyamide, polyacetel, modified PPO (PPE), polyester, polyallylate, unsaturated polyester, phenol resin, epoxy resin, polybutylene terephthal It is composed of plastics such as eight resins and nylon, and engineer plastics. In addition, thermoplastic resins such as ABS resin, polypropylene, and polyvinyl chloride may be used.
[185] In addition, it is preferable to improve the ultraviolet light resistance by attaching an inverter to the light-receiving side and using carbon black as a pigment or applying a resin coating material that absorbs UV rays to the light-receiving surface.
[186] Next, the photovoltaic device and the method of manufacturing the photovoltaic system of the present embodiment will be described.
[187] (Manufacturing method)
[188] 6 is a schematic external view of the photovoltaic power generation system of this embodiment, 602 is a solar cell in the above-described configuration, 2 is a DC-DC converter, and 3 is an inverter, 4 shows a load and 5 shows a commercial system.
[189] More specifically, first, as the conductive substrate 10, a roll of a cleaned long stainless steel substrate having a thickness of 0.1 mm, a width of 250 mm, and a length of 300 mm is conveyed, and the Al layer containing 1% of Si as the lower electrode layer 11. Is formed to a thickness of 5,000Å by sputtering method. Next, p / i / n-type amorphous silicon semiconductor layer 12, an n-type semiconductor PH _3, SiH ₄ and H ₂ gases and, as the i-type semiconductor, SiH ₄ and H ₂ gas, and a p-type semiconductor B By forming using ₂ H ₆ , SiH _4, and H ₂ gases, an N-type semiconductor layer having a thickness of 300 μs, an i-type semiconductor layer having a thickness of 4000 μs, and a p-type semiconductor layer having a thickness of 100 μs are formed by a CVC method. It is formed for each film forming apparatus that passes.
[190] Next, as the upper electrode layer 13, ITO having a film thickness of 800 GPa is formed by resistance heating deposition.
[191] Next, in order to divide the photovoltaic layer prepared in the above manner into a plurality of parts, an etching paste containing FeCl ₃ , AlCl _3, etc. was applied by using a screen printing method, the divided upper electrode was heated, washed and A portion of the upper electrode is removed in a linear shape, and an etching line 115 having a width of 1 mm is formed at an interval of 5,500 mm, and a photovoltaic layer is separated by an etching line.
[192] Next, as shown in Fig. 4, first, the polyimide substrate double-sided adhesive tape 25 (200 μm in thickness (base 100 μm)) is an insulating double-sided adhesive tape having a width of 7.5 mm on one side of the light receiving side of the conductive substrate. Fest continuously.
[193] Next, carbon wiring made of φ100 μm copper wiring previously coated with carbon fest is formed as a current collecting electrode 14 by a 5.6 mm pitch and a polyimide base double-sided adhesive tape 25 in the power generation region of the photovoltaic layer.
[194] Next, a width of 5 mm, a length of 245 mm, and a thickness of 100 μm were placed on the polyimide base double-sided adhesive tape 25, which is a plated copper foil, which is a light receiving surface terminal member 16, and 200 ° C., about 4 × 10 ⁵ Pa cm ² ), and simultaneously heated and pressure-bonded under the condition of 180 seconds.
[195] In addition, as shown in Fig. 5, the transparent thin film resin layer 23 is laminated on the light receiving surface of the solar cell by coating a fluorine resin pigment to a thickness of 100㎛ using a spray coating method. The transparent thin film resin layer is laminated to cover only a portion having photoelectric conversion characteristics with respect to the incident surface of the solar cell.
[196] Next, the transparent thin film resin layer is cut from the roll along the etching line at an interval of 5,500 mm to obtain a solar cell 602 (FIG. 6) having a transparent thin film resin layer formed on the conductive substrate.
[197] As a connection terminal to the DC-DC converter 2, a drawing member (not shown) is connected to the light receiving surface terminal member 16 and the conductive substrate 10, and received at 500 mm intervals using a silicone adhesive. Ten DC-DC converters 2 are adhered to cover a part of the side terminal member 16, and the input member of the drawing member and the DC-DC converter 2 described above are connected to the DC-DC converter 2; After connecting to the inside of the cover, the cover covers the DC-DC converter 2, and in this way forms a photovoltaic device 601 installed by the DC-DC converter 2 shown in FIG. . In this embodiment, the conductive substrate 10 functions as an electrode with drawing power from the solar cell.
[198] Next, the photovoltaic device 601 is fastened to the support 56 using an epoxy resin adhesive.
[199] Next, the ten DC-DC converters 2 attached to the solar cell 602 are sequentially connected using the connection cable 24 and collectively input to the inverter 3.
[200] The connecting cable 24 includes two positive and negative electrical wirings, each of which is electrically connected to an output terminal of the DC-DC converter inside the DC-DC converter, and also adjacent to the DC-DC. It is electrically connected to a cable connected to the converter.
[201] Using the same method, the photovoltaic devices 601 are sequentially installed on the ten supports 56 using the same method, and their outputs are converted into AC power through the inverter 3 to load 4 or Supplied to the system 5.
[202] (Explanation of the action)
[203] Here, using the circuit diagram of the DC-DC converter 2 shown in FIG. 7 and the inverter 3 shown in FIG. 8, the main circuit, the control circuit, and their respective operations will be described in detail.
[204] In the DC-DC converter 2 shown in FIG. 7, the output of the solar cell is accumulated in the capacitor 28 through the input terminal 27 of the DC-DC converter 2 to form a MOSFET 29, 30. ) Is converted to AC power by turning ON / OFF alternately.
[205] Next, the AC power input to the switching transformer 31 is converted into AC power according to a predetermined transformer ratio (1: 175 in the present embodiment), and further rectified by the diode bridge 32 to filter the filter capacitor ( After passing through 33, it is output from the DC-DC converter 2 to the inverter 3.
[206] Although not used in the present embodiment, the filter coil may be provided between the diode bridge 32 and the filter capacitor 33, and both the filter capacitor and the filter coil may be omitted depending on the configuration of the system.
[207] Next, the control circuit of the DC-DC converter 2 will be described. The control circuit 34 of the present embodiment includes a control power supply generation circuit 35, a reference waveform generation circuit 36, and a MOSFET driver 37. An input of the control power supply generation circuit 35 is a capacitor 28. Are connected at both ends, and the control signal output of the MOSFET driver 37 is connected to the gates of the MOSFETs 29 and 3.
[208] The detailed operation of the control circuit 34 will be described below. When the voltage of the solar cell 1 reaches the start voltage of the control power supply generation circuit 35, the output voltage of the control power generation circuit 35 is applied to the reference waveform generation circuit 36 and the MOSFET driver 37. Is entered.
[209] Next, first, the reference waveform generation circuit 36 operates, inputs a square wave of a preset reference frequency to the waveform input unit of the MOSFET driver 37, and inputs the gate driving signals S1 and S2 to the MOSFET driver 37. By inputting from the gates of the MOSFETs 29 and 30 to the MOSFETs, the MOSFETs 29 and 30 are alternately turned on and off at fixed heads.
[210] As shown in FIG. 8, the main circuit of the inverter 3 includes an input terminal 38, a smoothing capacitor 39, and a transistor 40a to which output power of the plurality of DC-DC converters 2 is input. A full bridge circuit 41 composed of 40b, 40c and 40d, a coil 42, and a capacitor 43.
[211] In addition, the control circuit of the inverter 3 is divided into parts for controlling start / stop of power conversion, optimization of an operating point of a solar cell, operation mode, and the like, but related to PWM control according to the present invention. Only the part will be described in detail with reference to FIG.
[212] As shown in the figure, the PWM control section input voltage detection circuit 45, band pass filter (BPF) 46, output current detector 47 (shown in Figure 8), DC voltage constant control circuit 48 Gate driving circuit for driving the transistors 40a to 40d of the DC voltage reference voltage source 49, the multiplier 50, the output current control error amplifier 51, the PWM modulation circuit 52 and the full bridge circuit 41; Furnace 53.
[213] In addition, as a specific method of PWM control, first, the input voltage detection circuit 45 detects the inverter input voltage V _DC , and the DC voltage constant control circuit 48 is connected to the DC voltage reference voltage source 49. The error signal S7 is generated to indicate the difference between the inverter input voltage V _DC and the reference voltage V _ref , and the error signal S7 is used as an input to the amplifier 50. In addition, the commercial system voltage V _cs is detected, the BPF 46 is taken out as a reference wave component, and its reference sinusoidal wave signal S8 is input to the amplifier 50 as the other input. The amplifier 50 multiplies the input error signal S7 by the reference sine wave signal S8 to generate the inverter output current reference signal S9.
[214] In addition, the error amplifier 51 receives the inverter output current reference signal S9 and the inverter output current I _OUT detected by the output current detector 47 from the amplifier 50 as an input, and receives the difference between the two. The modulation reference error signal S10 obtained by the amplification is output to the PWM modulation circuit 52. The PWM modulation circuit 52 performs PWM control based on the input modulation reference error signal S10, and the transistors 40a to (S6) by the gate driving signals S3 to S6 via the gate driving circuit 53. 40d), and the transistor is controlled to obtain an inverter input voltage (V _DC ) that matches the reference voltage (Vref).
[215] Since the operation of the full bridge circuit is well known, a description thereof will be omitted below.
[216] Therefore, when the outputs of the plurality of DC-DC converters 2 which control the switching operation of the MOSFET at a fixed duty so that the boost ratio is constant, the DC-DC conversion is connected to the inverter 3 which performs the input voltage constant control. The device 2 operates at a constant input voltage. This is because the DC-DC converter which performs the boost voltage ratio constant control at the fixed duty acts as an impedance converter, and as a result, the operation voltage of the solar cell is controlled to be constant.
[217] That is, when the input voltage of the inverter 3 is set to 175V in this embodiment, the output voltages of all the DC-DC converters 2 connected to the input side of the inverter 3 are about 175V, and the solar cell The operating voltage is operated at about 1 V, which is the optimum operating voltage in accordance with the boosted voltage ratio of the switching transformer.
[218] Although the case where the inverter 3 performs the input voltage constant control so far has been described, the electric current from the voltage and the current of the inverter input unit can be measured by using a current detection circuit (not shown) for the input unit of the inverter. The magnitude of the power can be maximized by controlling the input voltage of the inverter to perform maximum power point tracking control.
[219] In this case, the input voltage of the DC-DC converter 2 can be changed by changing the input voltage of the inverter 3, that is, the output voltage of the solar cell can be changed, so that the fluctuation of daylight occurs. Even so, the output voltage of the solar cell can be set only through the maximum power tracking control of the inverter 3 so as to maximize the input power to the inverter 3.
[220] As shown above, this embodiment forms a large and long solar cell on a conductive substrate, which is essential for a conventional solar cell module, which is a conventional manufacturing process, such as a cutting process, an end etching process, a serial connection process, and a bypass diode connection. By eliminating the process and the like, the manufacturing and material costs are reduced and the area luminous efficiency of the photovoltaic device is significantly improved.
[221] In addition, instead of sequentially setting the solar cells at regular intervals, the present embodiment is installed by requiring only a photovoltaic device having a large area of long solar cells formed on one conductive substrate to be installed on a support. Keep your work simple Therefore, in comparison with the installation work in which each sheet is installed one by one and connected individually, the present embodiment can shorten the time required for installation in a photovoltaic device and can reduce the installation cost.
[222] In this embodiment, since a plurality of DC-DC converters are connected in parallel to a large area long solar cell formed on one conductive substrate, the plurality of solar cells are connected in parallel by a wiring member and outputted. When the voltage step-up ratio is almost n times in the DC-DC converter, compared to the conventional configuration in which the inverter is collectively connected to the inverter, when the wiring (same resistance value) of the same cross-sectional area is used, current loss is (1 / n). It can reduce to an extent. By significantly reducing the cross-sectional area of the members connecting the DC-DC converters in parallel, the material cost can be greatly reduced and the weight can be reduced to facilitate the installation.
[223] In addition, due to the absence of series-connected solar cells, the partial shadow is limited only to the DC-DC converter in the vicinity of the region where the partial shadow occurs and does not affect other DC-DC converters. This can constitute a photovoltaic power generation system with a very small effect of partial shadows as compared with a conventional series connected solar cell. Compared with the conventional system of the same generating capacity, this has a very significant effect compared to the generating capacity.
[224] Further, in the above-described conventional system having the solar cells connected in series, the output characteristics of the individual solar cells vary, so that the solar cells having poor output characteristics affect other solar cells so that the whole solar cell is affected. Reduce the output of the photovoltaic system. On the other hand, the photovoltaic power generation system of this embodiment is composed of one solar cell on a conductive substrate, and a semiconductor layer, an electrode layer, and the like of one conductive substrate can be obtained through continuous film formation, resulting from manufacturing. The change in the characteristics of the solar cell can be reduced and the change in output characteristics can be significantly reduced.
[225] Therefore, the photovoltaic power generation system of the present embodiment can obtain a special effect that has not been conventionally obtained that reduces the loss caused by the shadow loss or the loss due to the characteristic change.
[226] In addition, the DC-DC converter connected to the solar cell can control the fixed voltage step-up ratio with a fixed duty, and the inverter connected in parallel to a plurality of such DC-Dc converters performs input voltage constant control or maximum power. By performing the point tracking control, one inverter can control the operating points of the individual solar cells, simplifying the control unit of the individual DC-DC converters, improving reliability and reducing costs.
[227] In a conventional photovoltaic power generation system having a solar cell connected in series, a structure in which such live pavt is exposed, for example, simplifying and / or parallelizing the radiation resistant coating of the solar cell. Although the solar cell is connected to a member that can be used without the insulation coating, it causes the following problems.
[228] That is, since the wiring member and the electrode of the solar cell and at least part of the charging part of the series or parallel connection member of the solar cell are exposed and non-insulated, the moisture and wet conditions (resistance between the solar cell charger and the ground) due to rain or the like. The solar cell charging section]-[rain]-[wet support material]-[rain]-[ground] or [solar cell charging section]- A leakage current path is formed in the path of [ratio]-[ground].
[229] This causes a problem that the metal ions constituting the charging part flow out from the charging part and promote corrosion of the electrode, the wiring member or the series / parallel connection member. In particular, when copper is used for the parallel-parallel connection member, it is understood that a current path is formed, copper is ionized, elution is remarkable, and the life of the connection member is significantly reduced.
[230] That is, in the above-described conventional photovoltaic power generation system, when a plurality of solar cells are connected in series, the potential difference with the earth becomes very large at the end closest to both electrodes of the series connection body, so that the corrosion of the connection member is easily facilitated. do. In order to cope with this, it is conceivable to connect the solar cells in parallel, but in this case, the number of solar cells connected in parallel increases and the current flowing increases. Since current collection loss is proportional to the square of the current, attempting to suppress current collection loss below a certain value causes a problem that the cross-sectional area of the parallel connection member becomes considerably large.
[231] In this embodiment, in order to promote low cost, a plurality of DC-DC converters are connected to one solar cell even in a case where the charging unit is exposed to the solar power generation system. As a result, since the potential of the solar cell is very small with respect to the earth, compared with the conventional system which performs serial connection, corrosion promotion of a wiring member can be prevented and reliability improves.
[232] (Second embodiment)
[233] A second embodiment of the photovoltaic power generation system according to the present invention will be described below. The description of the same parts as those of the first embodiment will be omitted, and the characteristic parts of this embodiment will be mainly described below.
[234] FIG. 10 is an external view showing a schematic configuration of a second embodiment, and FIG. 11 is an equivalent circuit diagram of a second embodiment.
[235] As the solar cell 1 of this embodiment, the same one as that of the first embodiment is used, and detailed description thereof is omitted.
[236] 12 is an enlarged view of a connection portion between the solar display cell 1 and the DC-DC converter 2 of the present embodiment. Here, the position of the solar cell to which the DC-DC converter 2 is attached is the same as that of the first embodiment, but in the second embodiment, the output terminal 59 has an exterior of the DC-DC converter 2. The points derived from wealth are different.
[237] The output terminal 59 is a terminal member which is connected to the high voltage side output terminal of the DC-DC converter 2, and moisture or the like enters the DC-DC converter 2 through the outlet roll of the output terminal 59. In order to prevent that, the inside of the DC-DC converter 2 is charged with a filler.
[238] Incidentally, the same circuit in the first embodiment described with reference to FIG. 7 is used as the internal main circuit of the DC-DC converter 2 of the present embodiment, but as shown in the circuit shown in FIG. In the embodiment, the first low voltage side is electrically connected to the conductive substrate 10 of the solar cell 1 by connecting the first low voltage side terminal and the second low voltage side terminal of the switching transformer 31 to the same potential as the second low voltage side. To have.
[239] Next, as shown in FIG. 14, the copper band 62 having a cross-sectional area of 0.1 mm is previously disposed on the support body 56 using an epoxy adhesive as a parallel connection member, and the DC-DC converter 2 Is bonded to the support body 56 using an epoxy-based adhesive, and the output terminals derived from the DC-DC converter 2 are electrically connected to the copper band 62 one by one.
[240] In addition, the inter-device wiring member 63 on the low voltage side is connected to the conductive substrate 10, the inter-device connecting member 63 and the copper band 62 are input to the inverter 3, and respective DC-DCs are connected. The DC power output from the converter 2 is converted into AC power and interconnected to a load or a commercial system.
[241] This embodiment uses the high frequency link type inverter 64 as shown in FIG. 15 as the inverter 3. The inverter 64 converts DC output from the DC-DC converter 2 into high-frequency AC by the high-frequency inverter 65, applies insulation by the small high-frequency transformer 67, and provides AC / The DC converter 67 converts AC into DC, and the DC / AC converter 68 converts AC into commercial AC and outputs the AC.
[242] Next, the present embodiment completes the photovoltaic power generation system by grounding the copper band 62 as shown in FIG. That is, in the configuration of this embodiment, since each DC-DC converter 2 is electrically united through the conductive substrate 10 of the solar cell 1, the output terminal of each DC-DC converter One side of the circuit board has excellent characteristics that only one wiring member is sufficient for wiring to a conductive substrate and for connecting a DC-DC converter.
[243] In addition, in order to reduce the cost, the above embodiment employs a technique of coating only the active region by the transparent thin film layer without using any sealing member.
[244] As described above, by grounding the copper band 62 which is the parallel connection member, the copper band 62 which is the high voltage side of the parallel connection member has a zero potential with respect to the earth as shown in the equivalent circuit diagram of the photovoltaic system of FIG. Has
[245] Therefore, the low voltage side of the parallel connection member becomes negative potential with respect to the earth, the conductive substrate 10 connected thereto has the same potential, and the low voltage side of the solar cell 10 becomes negative potential.
[246] At this time, the voltage at both ends of the solar cell 1 is smaller than the potential difference between the copper band 62 and the conductive substrate 10, and the member of the high voltage side such as the light receiving surface terminal part of the solar cell 1 is grounded. By maintaining the negative potential with respect to, it is possible to prevent corrosion of the wiring member.
[247] This embodiment uses the parallel connection member 62 and the device interconnection member 63. However, as the physical property of copper, copper is applied when the positive electrode is applied as shown in the potential -pH diagram shown in FIG. It can be seen that it is easy to elute. In view of the physical properties, the present embodiment is designed to prevent the elution of copper by keeping the wiring member made of copper at zero or negative potential with respect to the earth.
[248] As shown above, according to the photovoltaic power generation system of this embodiment, in addition to the effect obtained in the first embodiment, the potential of the solar cell and the wiring portion with respect to the ground is zero or a negative potential, and the corrosion of the wiring electrodes and the like is prevented. This has the effect of improving reliability.
[249] (Third Embodiment)
[250] A third embodiment of the photovoltaic power generation system according to the present invention will be described below. The description of the same parts as those of the first and second embodiments will be omitted, and the characteristic parts of the present embodiment will be mainly described below.
[251] The solar cell used in this embodiment has almost the same structure as that used in the first embodiment, but differs only in the lamination structure of the semiconductor layer.
[252] More specifically, A1 containing 1% of Si as the lower electrode layer is formed on the cleaned 0.1 mm thick roll-shaped long sterile steel substrate with a film thickness of 5000 kPa by the sputtering method. Next, n / i / p type amorphous silicon semiconductor layer, using B ₂ H _6, SiH ₄ and H ₂ gas as a p-type semiconductor, and the use of SiH ₄ and H ₂ gas is used as the i-type semiconductor and n-type semiconductor By using the PH ₃ SiH ₄ and H ₂ gas to form a p-type semiconductor layer having a thickness of 100 Å, an i-type semiconductor layer with a thickness of 4,000 ,, an n-type semiconductor layer having a thickness of 300 Å Form.
[253] Next, another n / i / p type amorphous silicon semiconductor layer is laminated to form a dual layer.
[254] Next, ITO having a film thickness of 800 kW is formed as an upper electrode by using resistance heating deposition to form a solar cell.
[255] Next, from here, the same process as that of the first embodiment is used, and one solar cell is completed on the conductive substrate. Next, the plurality of DC-DC converters are connected to the present solar cell at regular intervals.
[256] In this embodiment, since the n / i / p type amorphous silicon semiconductor layer is used for the solar cell, the conductive substrate side becomes a high voltage on the high voltage side of the solar cell differently from the first embodiment. As shown in FIG. 19, inside the main circuit of the DC-DC converter 2, the high voltage side on the primary side and the high voltage side on the secondary side of the switching transformer 31 are connected to the solar cell 1801. By electrically connecting to the conductive substrate 10, the high voltage side on the primary side and the high voltage side on the secondary side have coin positions.
[257] Next, as in the case of the second embodiment, in the present embodiment, the photovoltaic device is installed on the support 56, and is connected to the inverter 3 and the conductive substrate 10 is grounded, as shown in FIG. As described above, the photovoltaic power generation system of the present embodiment is obtained.
[258] As the inverter 3, a high frequency link type inverter is used as in the case of the second embodiment.
[259] In this embodiment, a bare copper band is used as the low voltage side member 62 of the parallel connection member, but one having an insulating coating can be preferably used.
[260] In order to reduce costs, the present embodiment uses a technique of coating a transparent thin film layer only in an active region in which no sealing member is used, and the entire circuit configuration of the photovoltaic system can be expressed as shown in FIG. 18. have.
[261] As shown in the equivalent circuit diagram of the photovoltaic power generation system shown in FIG. 18, the high voltage side of the solar cell 1801 is grounded by grounding the conductive substrate 10, which is a common electrode of each solar cell 1801. The inter-device wiring member 63 becomes zero potential with respect to the ground.
[262] Therefore, all other wiring members can maintain the negative potential with respect to the earth and in this way can prevent the progress of corrosion of the wiring members.
[263] Therefore, according to the photovoltaic power generation system of the present embodiment, in addition to the effects obtained in the first embodiment, the potential of the solar cell and the wiring member becomes zero or a negative potential with respect to the ground, thereby preventing corrosion of the wiring electrode or the like. Can improve the reliability.
[264] (Example 4)
[265] A fourth embodiment according to the present invention will be described below. The description of the same parts as those in the first to third embodiments will be omitted, and the characteristic parts of this embodiment will be mainly described below.
[266] 20 shows a part of a solar cell used in the photovoltaic device of this embodiment. As shown in the figure, the solar cell 1 used in this embodiment has the same configuration as the solar cell of the first to third embodiments, but the conductive substrate is provided without a semiconductor layer at both ends of the conductive substrate. The unit 130 is installed.
[267] The specific manufacturing method is the same as that of the first embodiment, and the rolled clean stainless steel substrate of 0.1 mm thickness is used as the conductive substrate, and the lower electrode layer, the semiconductor layer, and the upper electrode layer have a margin of 20 mm from both ends of the conductive substrate. And an area which is stacked on the conductive substrate and on which these layers are not provided is used as the mounting portion 130.
[268] Next, as shown in FIG. 20, the etching line 131 is formed to separate the installation part 130 and the charging part by removing the region between the upper electrode layer and the installation part 130 in a linear manner.
[269] In addition, as in the case of the first embodiment, a DC-DC converter 2 is installed to form a photovoltaic device and then mounted on a support.
[270] In this embodiment, the concrete nail is placed on the mounting portion 130 by the tracker at a 30cm interval to fix the DC-DC converter to the support.
[271] Although a concrete material is used as the support, the support can be formed by wood, plastic, or the like, and in this case, the support can be fixed using nails and screws or the like.
[272] Therefore, this embodiment reduces the installation cost by using a configuration that also facilitates installation of the photovoltaic device.
[273] (Example 5)
[274] A fifth embodiment according to the present invention will be described below. The description of the same parts as in the above-described embodiment will be omitted, and the characteristic parts of the embodiment will be mainly described below.
[275] FIG. 21 is a schematic configuration diagram of the present embodiment, and as shown in the drawing, the photovoltaic device 2001 according to the present embodiment includes a plurality of DC-DC converters 2004 connected to the solar cell 2002. do.
[276] As the solar cell 2002 used in this embodiment, the same thing as the solar cell is used before performing the coating process of the transparent thin film resin layer of the second embodiment, and the plurality of DC-DC converters 2004 receive light. The surface terminal member 2005 is electrically connected to the conductive substrate.
[277] In addition, the output terminal (not shown) of each DC-DC converter is connected to the terminal member 2005, so that all the DC-DC converters 2004 are connected in parallel.
[278] In this embodiment, the entire solar cell assembly is hermetically sealed in a state where the DC-DC converter is connected by the weather resistant film, the filler, and the backing material. FIG. 22 is a cross-sectional view taken along the line 22-22 in FIG. 21 (2006) is a weather resistant film, (2007) is a filler, (2008) is a backing material, (2009) is a light receiving surface terminal and (2010) is a double-sided adhesive tape.
[279] As an example of a specific material used for the sealing, ETFE (ethylene tetrafluoroethylene) is preferred as weather resistant film 2006, EVA (ethylene-vinyl acetate copolymer, weather resistant glade) is preferred as filler (2007) PVF / Al / PVF and the like are preferred as the backing material (2008).
[280] As a sealing method, the laminated body formed by laminating | stacking a back material, a filler, a solar cell assembly, a filler, and a weatherproof film in order is manufactured by melting a filler at 150 degreeC using a vacuum laminator.
[281] In this case, the terminal member 2005 drawn from the solar cell assembly is exposed from the end of the sealing member, and the terminal member 2005 is electrically connected to the solar power generator or the inverter.
[282] The photovoltaic device of this embodiment has the same effect as that of the second embodiment.
[283] (Other embodiment)
[284] The photovoltaic power generation system according to the embodiment of the present invention described above supplies electric power to a commercial power system. However, the photovoltaic power generation system of the present invention is an AC power system other than a commercial AC power generation system such as a self-flow generator in a factory or the like. It can be used by supplying power to it.
[285] As described above, the present invention can configure a solar power generator using a single large-length solar cell having a large area. This reduces manufacturing and material costs by eliminating the need for a cutting process, end etching process, series connection process, bypass diode connection process, and the like, which are conventionally required for manufacturing a solar cell module. It also improves the efficiency of the power generation area of the photovoltaic device.
[286] Since the photovoltaic device is composed of only one solar cell on a substrate, a semiconductor layer, an electrode layer, and the like can be obtained for one conductive substrate by continuous film formation. This can significantly reduce the variation of characteristics and the effect of partial shadows compared to conventional systems having solar cells connected in series.
[287] In addition, by significantly reducing current collection losses, the yellow cross-sectional area of the member-connected DC-DC converter in parallel is significantly reduced, material costs are significantly reduced, weight is reduced, and installation ease is improved.

权利要求:
Claims (20)
[1" claim-type="Currently amended] One solar cell formed on a substrate,
A plurality of power converters connected to the solar cells individually to convert output from the solar cells;
Photovoltaic device comprising a.
[2" claim-type="Currently amended] The method of claim 1,
The plurality of power converter is a photovoltaic device, characterized in that the DC-DC converter for boosting the DC voltage output from the solar cell.
[3" claim-type="Currently amended] The method of claim 1,
The plurality of power converter is a photovoltaic device, characterized in that the inverter.
[4" claim-type="Currently amended] The method of claim 1,
And a wiring member electrically connected to the solar cell and the power converter having an exposed portion at least in part of the charging portion.
[5" claim-type="Currently amended] The method of claim 1,
The solar cell includes a photoelectric conversion layer, a current collecting electrode disposed on the light receiving side of the photoelectric conversion layer, a surface wiring member and a transparent thin film resin layer, and at least a part of the current collecting electrode or the surface wiring member is covered by a transparent thin film resin layer. Photovoltaic device characterized in that it has an exposed portion that does not support.
[6" claim-type="Currently amended] The method of claim 1,
The photovoltaic device is a photovoltaic device, characterized in that made of thin film silicon.
[7" claim-type="Currently amended] The method of claim 1,
And the substrate is conductive and the substrate side of the photoelectric conversion layer is formed of a positive electrode.
[8" claim-type="Currently amended] The method of claim 1,
And the substrate is conductive and one of the output of the solar cell and one of the output of the DC-DC converter are electrically connected to the substrate.
[9" claim-type="Currently amended] The method of claim 1,
And one of the output of the solar cell and one of the output of the DC-DC converter are at a low voltage side.
[10" claim-type="Currently amended] The method of claim 1,
And one of the outputs of the solar cell and one of the outputs of the DC-DC converter are connected to a high voltage side.
[11" claim-type="Currently amended] The method of claim 1,
The solar cell is a photovoltaic device, characterized in that the power generator has a portion that is not formed on the two outer peripheral side.
[12" claim-type="Currently amended] The method of claim 11,
The solar cell is a photovoltaic device, characterized in that fixed to the support via a portion where the power generation unit is not formed.
[13" claim-type="Currently amended] The method of claim 1,
The solar cell or the photovoltaic device itself is a photovoltaic device, characterized in that sealed by a resin.
[14" claim-type="Currently amended] The method of claim 1,
The solar cell is a photovoltaic device characterized in that the lowest power generating unit that functions as a solar cell.
[15" claim-type="Currently amended] The method of claim 14,
And a plurality of current collecting electrodes for separately collecting power of the solar cell, wherein each of the plurality of current collectors is connected to one of a plurality of power converters to collect power individually collected by the plurality of current collecting electrodes. Photovoltaic device, characterized in that converted individually.
[16" claim-type="Currently amended] A photovoltaic device comprising a single solar cell formed on a substrate and a plurality of DC-DC converters individually connected to the solar cell to convert the DC output of the solar cell;
An inverter that converts the output of a plurality of DC-DC converters into AC power and supplies AC power to a load or interconnects AC power and commercial power systems.
Photovoltaic power generation system, characterized in that consisting of.
[17" claim-type="Currently amended] The method of claim 16,
The inverter has an insulation transformer, and the wiring member for connecting the DC-DC converter and the inverter is grounded.
[18" claim-type="Currently amended] In a photovoltaic device consisting of a single solar cell formed on a substrate and a photovoltaic power generation system consisting of a plurality of inverters individually connected to a solar cell for converting the output of the solar cell into AC power,
And said plurality of inverters supply output power to a load or interconnect output power to a commercial power system.
[19" claim-type="Currently amended] Forming a solar cell on a substrate by a semiconductor manufacturing process;
A process of connecting a plurality of power converters to predetermined portions of the solar cell
Method of manufacturing a photovoltaic device comprising a.
[20" claim-type="Currently amended] The method of claim 19,
Forming photovoltaic cells by continuously forming photoelectric conversion and collecting electrodes and surface wiring members on a substrate, and continuously connecting a power conversion device to a predetermined portion of the solar cells. Method of manufacturing a power generation device.

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同族专利:

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公开号 | 公开日

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US20040159102A1|2004-08-19|

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CN1503379A|2004-06-09|

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AU2003262482A1|2004-06-10|

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EP1429394A2|2004-06-16|

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US6966184B2|2005-11-22|

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KR100563687B1|2006-03-28|

引用文献:

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公开号 | 申请日 | 公开日 | 申请人 | 专利标题

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法律状态:
2002-11-25|Priority to JP2002340304

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2002-11-25|Priority to JPJP-P-2002-00340304

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2003-11-25|Application filed by 캐논 가부시끼가이샤

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2004-06-01|Publication of KR20040045387A

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2006-03-28|Application granted

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2006-03-28|Publication of KR100563687B1

优先权:

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申请号 | 申请日 | 专利标题

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JP2002340304|2002-11-25|

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JPJP-P-2002-00340304|2002-11-25|