JP2000077697A - Solar power generator - Google Patents

Abstract

(57) [Summary] To provide a photovoltaic power generator excellent in maintainability. A solar cell includes a plurality of solar cells electrically connected in series, and a bypass diode and a light emitting diode connected in parallel to each of the plurality of solar cells.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photovoltaic power generator for generating electric power by converting solar energy into electric energy, and more particularly, to preventing output from being stopped when a solar cell fails. The present invention relates to a technology for facilitating the discovery of a failed solar cell.

[0002]

2. Description of the Related Art Conventionally, as a photovoltaic power generation system, a flat plate type power generation system and a condensing and tracking type power generation system are known. The flat-panel power generation system is configured to extract electric power from, for example, solar cell panels arranged two-dimensionally on the roof of a house. In this flat-panel power generation system, since the solar cells are fixedly arranged, there is a disadvantage that much of the sunlight is lost depending on the azimuth and elevation of the sun, and the effective power generation time is short.

On the other hand, the concentrating-tracking type power generation system includes a power generation unit in which a plurality of solar cells having a condensing lens are arranged on a frame that can rotate up, down, left, and right.
Then, by driving the frame according to a signal from the sun position sensor, the power generation unit is controlled so as to always face the sun. In this concentrating and tracking power generation system, the solar cell is controlled so that the incident angle of the sunlight is always zero or a value near the solar cell, so that power is generated as long as the sunlight is present. Therefore, there is an advantage that the effective power generation time is substantially increased.

[0004]

Since the solar cell used in the above-described solar power generation system has a small output by itself, a plurality of solar cells are connected so that a required voltage and current can be obtained. Have been. An actual photovoltaic power generation system is constructed by, for example, modularizing a plurality of solar cells connected in series to form a power generation module, and connecting a plurality of the power generation modules in series to obtain a required voltage and current. Have been.

When an open-mode failure occurs in any of the solar cells used in the photovoltaic power generation system configured as described above, all the solar cells are connected in series. The output of the photovoltaic system goes to zero. However, since the probability that a plurality of solar cells fail at the same time is very low, there is a demand that the power generation be continued in the remaining normal solar cells even if the output is low.

Further, when a failure occurs in any of the solar cells, the failed solar cell cannot be visually confirmed. Therefore, conventionally, the failure is repaired in the following procedure. That is, the maintenance person first specifies the failed power generation module by individually measuring the output of each power generation module using, for example, a tester.

Next, in order to know the failed solar cell in the specified power generation module, the work of measuring the output of each solar cell by using a tester or replacing the solar cell itself is performed. Therefore, it is necessary to carry the equipment for the repair to the place where the photovoltaic power generation system is set, and it takes a lot of time to identify and replace the solar cell, so that the maintainability is poor. There is a problem.

[0008] The present invention meets the above requirements and
The purpose of the present invention is to solve the above-mentioned problem. The purpose of the solar power generation system is to maintain the output even if the solar cell breaks down, and to easily perform repairs. It is to provide a device.

[0009]

In order to achieve the above object, a photovoltaic power generator according to a first aspect of the present invention includes a plurality of solar cells electrically connected in series, and a plurality of solar cells. A light emitting diode connected in parallel to each of the cells. According to this configuration, since the light emitting diode also has a function as a bypass diode, even if an open mode failure occurs in any of the solar cells, the output of the solar power generation device becomes zero. No, and the failed solar cell can be visually confirmed. In this solar power generation device, the light emitting diode connected in parallel to each of the plurality of solar cells and the solar cells can be integrally formed by a semiconductor process. According to this configuration, the number of components can be reduced, so that reliability can be improved and cost can be reduced.

Further, the photovoltaic power generator according to the first aspect can be configured by further connecting a bypass diode in parallel with each of the plurality of solar cells.
According to this configuration, since a bypass diode is provided in addition to the light emitting diode, an inexpensive light emitting diode, for example, which is commercially available, can be used.
Also in this solar power generation device, at least one of the light emitting diode and the bypass diode connected in parallel to each of the plurality of solar cells and the solar cell can be integrally formed by a semiconductor process. The same effect as described above is achieved.

A photovoltaic power generator according to a second aspect of the present invention comprises a plurality of power generation modules electrically connected in series for the same purpose as described above, wherein each power generation module is electrically The power generation module includes a plurality of solar cells connected in series, and a light emitting diode connected in parallel to each of the plurality of power generation modules. According to this configuration, the number of light emitting diodes used can be reduced as compared with the photovoltaic power generator according to the first aspect, so that reliability can be improved and cost can be reduced.

[0012] The photovoltaic power generator according to the second aspect,
A bypass diode may be further connected in parallel to each of the plurality of power generation modules. According to this configuration, there is an advantage that an inexpensive light emitting diode can be used as in the solar power generation device according to the first aspect.

[0013] Each of the plurality of power generation modules of the photovoltaic power generation device according to the second aspect has a condensing mechanism for guiding sunlight to each of a plurality of solar cells provided in the power generation module, It can be configured to include a sun position sensor for detecting a sun position, and a tracking mechanism for tracking the sun based on a signal from the sun position sensor so that the plurality of power generation modules face the sun.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings, taking a concentrating and tracking power generation system to which the present invention is applied as an example.

FIG. 1 is a perspective view, partially cut away, showing the entire appearance of a converging / tracking power generation system to which the present invention is applied. This condensing and tracking power generation system has 5 × 3 power generation modules 1 on a frame 12 supported by a support 11.
0 is fixed. Hereinafter, the 15 power generation modules are collectively referred to as a power generation unit 16.

At the lower end of the column 11, a horizontal drive mechanism 13 for rotating the entire frame 12 in the azimuth direction is provided. Also, a frame 1 is provided at the upper end of the support 11.
Vertical drive mechanism 14 for rotating the whole 2 in the elevation direction
Is provided. The tracking mechanism of the present invention is composed of the horizontal drive mechanism and the vertical drive mechanism.

Each power generation module 10 has a plurality of solar cells which generate DC power by being irradiated with light condensed by a lens, as will be described in detail later. The DC power generated by each solar cell is Are integrated and output to the outside. In this concentrating and tracking power generation system, each power generation module 10 is electrically connected in serial. As a result, the DC power from each power generation module 10 is integrated and output from an external terminal (not shown) to the outside as the power generated by the present concentrating and tracking power generation system.

A sun position sensor 15 for detecting the sun position is provided at a predetermined portion (upper portion in FIG. 1) of the frame 12. A signal indicating the direction of the sun obtained from the sun position sensor 15 (hereinafter, referred to as a "sun position sensor signal") is supplied to a control unit (not shown). The control unit operates the horizontal drive mechanism 13 and the vertical drive mechanism 14 based on the sun position sensor signal from the sun position sensor 15 so that the light receiving surface of the power generation unit 16 always vertically faces the sun. As a result, in this concentrating and tracking power generation system, power is generated while always tracking the sun.

Next, the details of the power generation module 10 will be described with reference to FIG.
This will be described with reference to FIG. In this embodiment, 4 × 3 solar cells are used for one power generation module 10. Note that the number of solar cells used in the power generation module 10 is not limited to the above, and can be arbitrarily determined.

As shown in the exploded perspective view of FIG. 2, the power generation module 10 includes a lens 20, a lens frame 21, a base panel 22, and a heat sink panel 23.

The lens 20 is constituted by a plate member made of, for example, an acrylic resin functionally divided into 4 × 3 regions, and a Fresnel lens 30 is formed in each of the 12 regions. . The light collecting mechanism of the present invention includes the Fresnel lens 30 and a secondary light collecting lens 53 described later.

The twelve Fresnel lenses 30 are formed to correspond to twelve cell assemblies 40 (details will be described later) provided on the base panel 22. When the Fresnel lens 30 is exposed to the atmosphere, the light transmittance of the Fresnel lens 30 may deteriorate over time. In order to avoid such a problem, it is preferable to provide, for example, an ultraviolet cut glass on the upper surface of the lens 20.

The lens frame 21 is formed in a box shape with upper and lower surfaces opened, and the lens 20 is fixedly supported by a frame on the upper surface. The lens frame 21 functions as a spacer for securing a distance corresponding to the focal length of each Fresnel lens 30 in cooperation with the base panel 22.

The base panel 22 is formed in a box shape having an open upper surface, and the frame on the upper surface is used to form the lens frame 21.
Is fixedly supported. As shown in FIG. 3, 4 × 3 cell assemblies 4 are provided on the bottom of the base panel 22.
0 is arranged. These 12 cell assemblies 4
Numerals 0 are electrically connected in series via the electrode leads of each cell assembly 40. This series connection is realized by connecting different electrode leads of adjacent cell assemblies 40 with a bus bar 41.

The positive electrode lead of the cell assembly 40 at one end of the twelve cell assemblies 40 connected in series is connected to the first output terminal 24 provided on one side surface of the base panel 22, The negative electrode lead of the cell assembly 40 is provided on a second side provided on the other side of the base panel 22.
They are connected to output terminals 25, respectively. Then, power is taken out from the first output terminal 24 and the second output terminal 25.

The heat sink panel 23 supports the base panel 22 by bonding the base panel 22 to the upper surface thereof with a heat radiation adhesive. The heat sink panel 23 is provided with a plurality of radiating fins, and is used for dissipating heat generated in each cell assembly 40 disposed on the base panel 22.

Next, the configuration of the cell assembly 40 is as follows.
This will be described with reference to the side view shown in FIG.

In the cell assembly 40, for example, a ceramic substrate 51 on which an electrode pattern is formed is bonded on a heat spreader 50 for diffusing heat, and a solar cell 52 is fixed thereon.
A secondary condensing lens (SOE) 53 is adhered to the upper surface of the device. A positive electrode lead 54 connected to the positive electrode of the solar cell 52 is provided from one end of the substrate 51, and a negative electrode lead 55 connected to the negative electrode of the solar cell 52 is provided from the other end. .

Further, the positive electrode lead 54 and the negative electrode lead 5
5, a bypass diode 60 and a light emitting diode 61 are connected in parallel. Light emitting diode 61
The light emitting state is disposed at a position visible through the lens 20, for example, or at a position visible from a hole (not shown) formed in the joint surface between the bottom surface of the base panel 22 and the heat sink panel 23.

The light condensed by the Fresnel lens 30 is guided to the upper surface of the secondary condensing lens 53. The secondary condenser lens 53 is provided to absorb the optical axis shift of the Fresnel lens 30. That is, even if the light from the Fresnel lens 30 is incident on a position shifted from the center of the upper surface of the secondary condenser lens 53, the total incident light is totally reflected by the inner wall surface of the secondary condenser lens 53, so that the total incident light is It is led to the cell 52. As a result, light energy is converted into electric energy in the solar cell 52, and output as electric power from the positive electrode lead 54 and the negative electrode lead 55.

Next, the electrical configuration of the photovoltaic power generator configured as described above will be described. FIG. 5 shows the first embodiment of the present invention.
FIG. 2 is a circuit diagram showing an electrical configuration of a power generation module 10 used in the solar power generation device according to the embodiment. The power generation module 10 is configured by connecting 12 solar cells 52 in series. The output of the power generation module 10 is taken out from the first output terminal 24 and the second output terminal 25. In each solar cell 52,
The bypass diode 60 and the light emitting diode 61 are respectively connected in parallel.

The bypass diode 60 is reverse biased when the solar cell 52 is operating normally. As a result, no current flows through this bypass diode 60. Similarly, the light emitting diode 61 is also
Is reverse biased when is operating normally. As a result, no current flows through the light emitting diode 61, so that the light emitting diode 61 is not turned on. The maintenance person can confirm that the solar cell 52 is normal by confirming that the light emitting diode 61 is turned off.

On the other hand, when an open mode failure occurs in the solar cell 52, the bypass diode 60 becomes forward biased. Thereby, the bypass diode 60
Current flows through Therefore, even if a failure in the open mode occurs in the solar cell 52, the output from the power generation module 10 only decreases and does not become zero. Similarly, when an open mode failure occurs in the solar cell 52,
The light emitting diode 61 is also forward biased. This allows
Since current flows through the light emitting diode 61, the light emitting diode 61 is turned on. Therefore, the maintenance person can recognize that the solar cell 52 is out of order by confirming that the light emitting diode 61 is turned on.
Cell assembly 4 including failed solar cell 52
By replacing 0, repair work can be performed in a short time.

It should be noted that one or both of the bypass diode 60 and the light emitting diode 61 can be formed on the same cell as the solar cell 52 by a semiconductor process. In this case, the number of components constituting the cell assembly 40 is reduced, so that the reliability can be improved and the component cost and the operation cost can be reduced. Further, the bypass diode 60, the light emitting diode 61, and the solar cell 52 can be configured as a hybrid module. In this case, the same effect as above can be obtained.

The light emitting diode 6 having a rated current larger than the current flowing through the entire circuit of the power generation module 10
If 1 is used, the bypass diode 60 can be omitted.

Next, a photovoltaic power generator according to a second embodiment of the present invention will be described with reference to the circuit diagram shown in FIG.

The power generation unit 16 of this solar power generation device
Is configured by connecting a plurality of power generation modules 10 in series. The output of the power generation unit 16 is taken out from the first external terminal 17 and the second external terminal 18 and supplied to a load. A bypass diode 70 and a light emitting diode 71 are connected to each power generation module 10 in parallel.

The bypass diode 70 is reverse-biased when the power generation module 10 is operating normally, that is, when none of the twelve solar cells 52 included in the power generation module 10 has a failure in the open mode.
Thus, no current flows through the bypass diode 70. Similarly, the light emitting diode 71 is also reverse biased when the power generation module 10 is operating normally. As a result, no current flows through the light emitting diode 71, so that the light emitting diode 71 is not turned on. The maintenance person can recognize that the power generation module 10 is normal by confirming that the light emitting diode 71 is turned off.

On the other hand, when an open mode failure occurs in the power generation module 10, that is, when any of the solar cell cells in the power generation module 10 has an open mode failure, or when the electrode leads of each cell assembly 40 are connected to these. When a disconnection occurs with the bus bar 41, the bypass diode 70 becomes forward biased. As a result, a current flows through the bypass diode 70.
Similarly, the light emitting diode 71 is also forward biased when the power generation module 10 is operating normally. As a result, a current flows through the light emitting diode 71, so that when an open mode failure occurs in the power generation module 10, the light emitting diode 71 is turned on. Therefore, the maintainer
By confirming that the light emitting diode 61 is lit, it is possible to recognize that the power generation module 10 is out of order. Therefore, by replacing the faulty power generation module 10, repair work can be performed in a short time. .

The light emitting diode 71 having a rated current larger than the current flowing through the entire circuit of the power generation unit 16
, The bypass diode 60 can be omitted.

In the solar power generation device according to the second embodiment, each solar cell 52 in each power generation module 10 is not provided with a bypass diode and a light emitting diode.
Each power generation module 10 is simply provided with a bypass diode and a light emitting diode. Therefore, there is an advantage that the number of components of the entire solar power generation device can be reduced.

In the first and second embodiments described above, the case where the present invention is applied to the converging / tracking type power generation system has been described. However, it is needless to say that the present invention can also be applied to a flat plate type power generation system. In this case, a bypass diode and a light emitting diode may be provided in parallel for each of all the solar cells used in the flat panel power generation system, or a solar cell panel on which a plurality of solar cells are mounted is regarded as one module. The bypass diode and the light emitting diode may be provided for each module.

[0043]

As described in detail above, according to the present invention,
Since a bypass diode is provided for each solar cell, the output can be continued even if one of the solar cells fails, and the maintenance can be performed easily because the failed solar cell or power generation module can be visually recognized. It is possible to provide an excellent solar power generation device.

[Brief description of the drawings]

FIG. 1 is a perspective view, partially cut away, showing the entire appearance of a converging / tracking type power generation system to which the present invention is applied.

FIG. 2 is an exploded perspective view showing the power generation module according to the embodiment of the present invention.

FIG. 3 is an exploded perspective view showing the base panel shown in FIG. 2 in detail.

FIG. 4 is a side view showing a schematic configuration of the cell assembly shown in FIG.

FIG. 5 is a circuit diagram illustrating an electrical configuration of a power generation module included in the solar power generation device according to the first embodiment of the present invention.

FIG. 6 is a circuit diagram showing an electrical configuration of a photovoltaic power generator according to a second embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 power generation module 11 support 12 frame 13 horizontal drive mechanism 14 vertical drive mechanism 15 sun position sensor 16 power generation unit 17 first external terminal 18 second external terminal 20 lens 21 lens frame 22 base panel 23 heat sink panel 24 first output terminal 25 first 2 output terminal 30 Fresnel lens 40 Cell assembly 41 Bus bar 50 Heat spreader 51 Substrate 52 Solar cell 53 Secondary condenser lens 54 Positive electrode lead 55 Negative electrode lead 60, 70 Bypass diode 61, 71 Light emitting diode

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Naofumi Nagata 1-10-1, Shinsayama, Sayama City, Saitama Prefecture Honda Engineering Co., Ltd. (72) Inventor Yuzo Nagai 1-10-1, Shinsayama, Sayama City, Saitama Prefecture Hong DA Engineering Co., Ltd. F term (reference) 5F051 JA02 JA09 JA10 JA13 JA20 KA02 KA07 KA08

Claims (7)

[Claims] 1. A photovoltaic power generator comprising: a plurality of solar cells electrically connected in series; and a light emitting diode connected in parallel to each of the plurality of solar cells. 2. The photovoltaic power generator according to claim 1, wherein the light emitting diode connected in parallel to each of the plurality of solar cells and the solar cells are integrally formed by a semiconductor process. 3. The photovoltaic power generator according to claim 1, wherein a bypass diode is further connected in parallel to each of said plurality of solar cells. 4. The solar cell according to claim 3, wherein at least one of the light emitting diode and the bypass diode connected in parallel to each of the plurality of solar cells and the solar cell are integrally formed by a semiconductor process. Power generator. 5. A plurality of power generation modules electrically connected in series, each power generation module including a plurality of solar cells electrically connected in series, and each of said plurality of power generation modules And a light emitting diode connected in parallel to the solar power generation device. 6. The photovoltaic power generator according to claim 5, wherein a bypass diode is further connected in parallel to each of said plurality of power generation modules. 7. Each of the plurality of power generation modules includes:
A light-condensing mechanism that guides sunlight to each of a plurality of solar cells provided in the power generation module, further comprising: a sun position sensor that detects a sun position; and The solar power generation device according to claim 5, further comprising: a tracking mechanism that tracks the sun so that the module faces the sunlight.