JPS6252477B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a solar cell power supply device in which a solar cell that does not emit light has the function of a blocking diode used when combining a solar cell array in which a plurality of solar cells are connected in series or in parallel. It is related to.

In general, solar battery power supplies that use solar cells as a power source generate very little power per solar cell in order to supply a predetermined amount of power.
For example, as shown in FIG. 1, solar cells are electrically and mechanically connected in series and parallel to form a solar cell array 1 with m series x n parallel solar cells, and these solar cell arrays 1 are connected with blocking diodes. 2 and are connected in parallel. This solar array 1
The diodes 2 and diodes 2 are arranged side by side on the solar cell substrate, and the diodes 2 are high power diodes, and one or two diodes 2 are provided for redundancy. The purpose of this blocking diode 2 is to prevent power loss caused by current flowing from a high output array to a low output array due to variations in the output voltage of each solar cell array 1. For example, in the case of artificial satellites, solar cell arrays may become hot due to damage caused by meteorite collisions or bending of metal fittings connecting solar cells due to temperature cycles.
Even if a short-circuit failure occurs between the (+) side and COLD (-) side electrodes, a blocking diode 2 isolates the failed array so that output from the remaining normal solar cell array can be obtained.

In particular, when this solar cell is used as a power source for an artificial satellite, it is impossible to repair it if it breaks down, so the blocking diode 2 must be used.

This solar power supply is mounted on the outside of the satellite to receive as much sunlight as possible, but the blocking diode is protected from radiation, solar UV rays, and severe temperature changes. Since the king diode is surrounded by a metal case, the weight of the blocking diode portion increases. In addition, the operating temperature of the blocking diode itself is -65℃~+
Since it is necessary to use the device within a temperature range of 120°C, the temperature of the solar cell board on which the blocking diode is mounted is designed so that it does not drop below -65°C, so at high temperatures it can reach +80°C. They were forced to create a thermal design similar to that of the previous one. Generally, the output of solar cells decreases by about 5% for every 10°C rise in temperature, so this thermal design has caused the problem of lower efficiency of solar cell output.

Furthermore, since the blocking diode 2 is usually cylindrical in shape, it is not easy to connect it to the solar cell array 1 or attach the blocking diode to the substrate, and it is difficult to withstand vibration, shock, and acceleration. There was a problem that the implementation method was complicated.

In order to solve these drawbacks, the present invention provides a solar cell power supply device that uses the solar cells themselves used in the solar cell array 1 as blocking diodes instead of using ordinary diodes.

The present invention will be explained in detail below with reference to the drawings.

FIGS. 2a and 2b are an equivalent circuit diagram of a solar cell and a side configuration diagram thereof. This solar cell 6 is represented by a constant current source 4 that is generated in proportion to the intensity of irradiated light, a source 5 having diode characteristics, and an internal resistance. If the light entering the solar cell 6 is blocked here, the constant current source 4 is removed and only the diode 5 and internal resistance are left, so the solar cell 6 can be used as a diode. Furthermore, the solar cell 6 is n
-Since the p-junction area is extremely large compared to a normal diode (for example, 2 cm x 2 cm square), it has high current and high breakdown voltage characteristics.

FIG. 3 is a block diagram of an embodiment of the present invention. As shown in this figure, a blocking diode can be realized by connecting a light-shielded solar cell 7 to the solar cell array 1 with reverse polarity.

FIG. 4 is a side view showing the specific configuration of FIG. 3. This is made by integrating a solar cell 6 and a transparent cover glass 8 with an anti-reflection coating on the substrate 3 in order to let in as much light as possible and to prevent deterioration of the output of the solar cell due to radiation. The components are electrically and mechanically connected in series and parallel by connecting fittings 9 to form a solar cell array.
Furthermore, in order to prevent deterioration of the diode characteristics due to radiation and to block light, we have combined the same solar cells as those used in solar cell arrays with a light-shielding substance on the surface of the cover glass. Cover 10 made of metal such as aluminum
The integrated solar cell 7 is operated as a blocking diode by connecting it to the solar cell array with a connecting fitting 11 with opposite polarity.

As explained above, the solar cells used as blocking diodes are exactly the same solar cells as the solar cell array, and the technology for attaching the cover that shields the light added to the solar cells also depends on the solar cells. Since the structure is exactly the same as that of the conventional blocking diode, there is no need for a different structure when using it as a blocking diode. Furthermore, the operating temperature range is -150℃~+
Since it can spread up to 150℃, the temperature can be lowered by about 80℃ compared to the -65℃ of conventional blocking diodes, increasing the solar cell array output by about 40% and simplifying thermal design. In addition, since the cover 10 of the solar cell, which serves as a blocking diode, only needs to be attached to the surface of the solar cell, the radiation prevention means is simpler than the structure of a conventional diode. Furthermore, since it can be electrically and mechanically coupled using the same means as a solar cell array, implementation is extremely simple. It should be noted that if a Mylar sheet or a Kapton sheet having a thickness of about several tens of microns to several hundreds of microns is used for the solar cell substrate 3 shown in FIG. 4, the structure will be thinner, which is advantageous in terms of mounting.

Although the embodiments of the present invention have been described with respect to N/P type solar cells, the same can be applied to P/N type solar cells.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a conventional solar cell power supply device, Fig. 2 a and b are an equivalent circuit diagram of a solar cell and its side view, Fig. 3 is a block diagram of an embodiment of the present invention, and Fig. 4 is a block diagram of a conventional solar cell power supply device. FIG. 4 is a side cross-sectional view of the solar battery power source of FIG. 3; In the figure, 1... solar cell array, 2... blocking diode, 3... solar cell substrate, 4... constant current source, 5... diode, 6... solar cell, 7... solar cell with cover, 8... cover glass, 9,11
...Connection fitting, 10...Cover.

Claims (1)

[Claims] 1 A solar cell group configured by connecting a plurality of solar cells in series or parallel, the light-receiving surface of which is covered with a material that does not transmit light, and the solar cell group is connected in the opposite direction to the connection polarity of each solar cell in the solar cell group. A solar cell power supply device characterized in that a second solar cell is connected to one end of the solar cell, and a plurality of solar cell groups to which the second solar cell is connected are connected in parallel.