JP2014212148A - Solar cell panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that the series number of solar cell arrays and a mounting layout must be reviewed in a design of the conventional solar cell panel at every time when design condition such as radiation environment is different.SOLUTION: Solar battery cells are prepared on which shields such as glass having different thickness are mounted. A solar cell array is created in which these solar battery cells having different shield thickness are connected in series based on a predetermined mounting ratio. The mounting ratio is determined on the basis of output voltage at the end of design life in an assumed dose of total radiation exposure. As a result, reduction and optimization of the series number of the solar cell arrays can be achieved, and cost of a solar cell panel can be reduced.

Description

The present invention relates to a solar cell panel. In particular, the present invention relates to a solar battery panel that is mounted on a spacecraft such as an artificial satellite or a spacecraft and needs to take into account the deterioration of the voltage of the solar battery cell due to radiation.

Many spaceships equipped with solar panels have been launched in outer space, but as spacecraft become more sophisticated, solar panels that can supply large amounts of power are required, making up solar panels. The number of solar cells in series and the number of parallel arrays of solar cells tend to increase.

As a factor of the voltage deterioration of the solar battery cell in the space environment, radiation incident on the solar battery cell can be cited. Conventionally, a method of protecting a solar battery cell with a shield such as glass is known as a measure for alleviating voltage degradation of the solar battery cell due to radiation (see, for example, Patent Document 1).

JP 2010-21350 A

Conventionally, as a countermeasure when the design conditions such as the radiation environment of the solar cell panel are changed, (1) reviewing the series number and mounting layout of the solar cell array, and (2) mounting on the solar cell. Change of shield thickness of glass or the like. In the review of the number of solar cell arrays in series and mounting layout in (1), there is a problem that an increase in cost due to an increase in the number of solar cells and, in some cases, a significant increase in cost / weight due to an increase in the number of panels. It was. In addition, in (2) changing the shield thickness of glass or the like mounted on a solar cell, solar cell panels used for spacecraft and satellites are required to have high reliability. Only those that have passed verification / certification tests simulating the environment to which ships and satellites are exposed can be mounted on spacecrafts and satellites, but changing the shield thickness of glass, etc. requires a second verification / certification test. There was a problem of having a large impact on panel costs and manufacturing plans.

Further, in the conventional solar cell panel design, when the number of series of solar cell arrays required for the design is not an integer, the number of series rounded up to the nearest decimal point must be mounted. There was a problem that extra material costs were required for the number of parallel lines.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a solar cell panel capable of reducing cost in a solar cell panel that needs to consider voltage degradation due to radiation.

A solar battery panel according to the present invention is a solar battery panel that is mounted on a spacecraft and includes a plurality of solar battery arrays in which solar battery cells are connected in series using an interconnector,
In the solar cell array, solar cells each having a plurality of shields having different thicknesses are connected to the light receiving surface side at a predetermined ratio.

According to the present invention, it is possible to reduce the number of mounted solar cells constituting the solar cell array with respect to solar cell panels having different design conditions such as radiation environment. By reducing the number of mounted solar cells, the cost can be reduced.

It is a side view of the solar cell array which comprises the solar cell panel which concerns on Embodiment 1 of this invention. It is a voltage-current characteristic view of each solar battery cell constituting the solar battery array of the solar battery panel according to Embodiment 1 of the present invention. It is a side view of the solar cell array which comprises the conventional solar cell panel. It is a side view of the solar cell panel corresponding to the radiation exposure dose increase by increasing the conventional serial stage number. It is a side view of a solar cell panel corresponding to an increase in predicted radiation exposure by thickening a shield such as glass on a conventional solar cell.

Embodiment 1 FIG.
1 is a side view of a solar cell array constituting the solar cell panel according to Embodiment 1. FIG. In FIG. 1, solar cells 1 are connected to each other by an interconnector 3, and a shield 2 such as glass is disposed on the light receiving surface side of the solar cells 1.
The number of solar cells 1 in series is N, and each of the solar cells 1 connected in series is classified by a subscript (1 ₁ to 1 _N ). Similarly, the shield 2 arranged on the light receiving surface side of each solar cell 1 (1 ₁ to 1 _N ) is divided by a subscript attached to the solar cell (2 ₁ to 2 _N ).

FIG. 3 is a side view of a solar cell array constituting a conventional solar cell panel. The solar cells 1 are connected to each other by an interconnector 3, and a shield 2 such as glass is disposed on the light receiving surface side of the solar cells 1.
Serial number of the solar cell 1 is N pieces, the solar cell 1 of each connected in series are denoted by the subscript 1 ₁ to 1 _N.

In the conventional solar cell panel, the shield 2 having the same thickness A is mounted on all the solar cells ( ₁₁ to 1 _N ) on the solar cell panel as shown in FIG.
On the other hand, in the solar cell panel according to Embodiment 1, two types of shields 2 having thicknesses A and B are arranged for the solar cells (1 ₁ to 1 _N ).
In the example of FIG. 1, K solar cells (1 ₁ to 1 _K ) on which a shield 2 (2 ₁ to 2 _k ) having a thickness B is mounted, and a shield 2 (2 _{k + 1} to _2N ) mounted (NK) solar cells (1 _{k + 1} to 1 _N ) are connected in series to form a solar cell array.

Here, consider the case where the total radiation exposure at the end of the design life of spacecraft and satellites is Φ.
FIG. 2 shows the voltage-current characteristic in the case of the total radiation exposure Φ of the solar cell mounted with the shield 2 having the thickness A, and the case of the total radiation exposure Φ of the solar cell mounted with the shield 2 of the thickness B. It is the figure which showed the voltage-current characteristic.

The maximum output voltage VAst in the thickness design life end of a solar array that implements the shield 2 (2 ₁ to 2 _N) of glass or the like of A, the glass of thickness A shield 2 (2 ₁ to 2 _N) The maximum output voltage of the mounted solar cell 1 (1 ₁ to 1 _N ) is VApmax, the required operating voltage of the satellite is VL, N is an integer, and s is a decimal number of 0 or less. The following two situations can be considered depending on the presence or absence.

Pattern 1 indicates that the number of solar cell arrays to be mounted needs to be (N + 1) in order to satisfy the required satellite operating voltage VL.
When the parallel number of the solar battery arrays constituting the solar battery panel is M, (1−s) × M solar battery cells are required.

Here, in this embodiment,

A solar cell array in which a shield B having a thickness B satisfying the above condition is selected and a solar battery cell mounted with a shield having a thickness A (for example, glass) and a shield having a thickness B (for example, glass) are connected in series at a predetermined ratio Newly provided. At this time, the output voltage of the solar cell array connected in series at a predetermined ratio is

It becomes. Thus, by adjusting the ratio of the number of series solar cells (N−k) on which the shield 2 of thickness A is mounted and the number of series solar cells k on which the shield 2 of thickness B is mounted, (1− s) The cost of M solar cells can be reduced.

In the above description, solar cells using two types of shields having different thicknesses have been described. However, the thickness of the shield is not limited to two types, and three or more types of shields are used. You may make it comprise a solar cell array using.

Next, consider the case where the total radiation exposure at the end of the design life of spacecraft and satellites becomes Φ + ΔΦ.
In both cases of pattern 1 and pattern 2 shown in equations (1) and (2), VApmax is

It becomes. here,

To meet

Thus, when the number of parallel solar cell arrays is M, n × M or more solar cells are additionally required.
here,

If you select a shield 2 of thickness B that satisfies

As shown in FIG. 1, the ratio of the series number (Nk) of solar cells on which a shield 2 such as glass of thickness A is mounted and the number k of series of solar cells on which shield 2 such as glass of thickness B is mounted. By adjusting, an increase in n × M or more solar cells can be avoided.

FIG. 4 is a side view of a conventional solar cell panel corresponding to an increase in radiation exposure by increasing the number of series stages, but this method increases the cost because the number of series of solar cell arrays increases. It was. FIG. 5 shows a change in the shield thickness of glass or the like mounted on a conventional solar battery cell, but this method has a great influence on the cost and the production plan.

As described above, according to the first embodiment, when the qualification test of the solar cell panel in which the shields of two kinds of glass or the like are mounted is completed, the mounting ratio is changed to change the design of the radiation environment or the like It is possible to reduce / optimize the number of solar cell arrays in series for solar cell panels with different conditions. Costs can be reduced by reducing / optimizing the number of solar cells.

1 solar cell, 2 glass shield, 3 interconnector.

Claims (2)

A solar battery panel comprising a plurality of solar battery arrays mounted on a spacecraft and connected in series with solar battery cells using an interconnector,
The solar cell array is formed by connecting solar cells each having a plurality of shields having different thicknesses on a light receiving surface side at a predetermined ratio. 2. The solar cell panel according to claim 1, wherein the predetermined ratio is determined based on an output voltage of each of the solar cells provided with shields having different thicknesses in a total radiation exposure amount.

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