JPS59195499A - Power supply device for artificial satellite - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] This invention provides an artificial satellite on an orbit in outer space.
Using a solar array consisting of solar cells that convert solar energy into electricity as a secondary power source, the main path line is stabilized during sunshine by consuming the surplus power of the solar array with a shunt circuit connected between the solar arrays. This invention relates to a shunt-regulator type artificial satellite power supply device.

FIG. 1 shows a typical configuration example of a conventional power supply device for this type of artificial satellite.

In the figure, (1) is a solar array that supplies power to one satellite during two days of sunshine. (2) is a non-shunt solar array, (3) is a shunt solar array, (4) is an intermediate tap, (5) is a main path line, (6) is a return path line, and (71 is a control path line).

(8) is a shunt circuit that consumes surplus power generated in the shunt part solar array (3), and is constructed of, for example, Darlington-connected power transistors.

(9) is an error amplifier, and the main path line (
The voltage of 5) (hereinafter referred to as main bus voltage) is compared with the reference voltage and the error signal is output. Power is supplied to the satellite when the solar array (1) cannot supply the necessary power, such as during the bieclipse period. α is a boost converter.

The purpose is to boost and stabilize the battery voltage at level 1, which is approximately the same as the main bus voltage during sunshine, and supply battery power to the main pass line (5).

OJ is the satellite load on the main path line (5).

Next, the operation of the power supply device shown in FIG. 1 will be explained.

When the satellite is illuminated by the sun, the power generated by the solar array (1) is transferred to the main path line (
5) and is supplied to the satellite load. During sunshine, the main bus voltage VBUS is compared with the reference voltage in the error amplifier (9), and its redundant error output signal is similarly subjected to a majority comparison in the majority logic circuit of the error amplifier (9), and then the The error signal is sent to the shunt driver 0.

During sunshine, the error signal is amplified by the drive amplifier in the shunt driver (!71-) in the operating area of the shunt driver (1@), and is output as a drive signal for the shunt circuit (8), and is output as a drive signal to the solar array (1). middle tap (
The control bus (7) connected to the shunt solar array (3) is connected to the shunt circuit, and the shunt solar array (3) is connected to the shunt circuit.
The surplus power generated in step 3) is consumed in the shunt circuit.

The operating principle of the above-mentioned shunt regulator system is shown in FIG.

In Fig. 2, the output current 1 of the non-shunt solar array f2+ is equal to the load current, and the output voltage ■1 is determined for ■1, and the output voltage v2 at the intermediate tap (4) of the shunt solar array (3) Then, V2 is adjusted so that v1+■2 becomes equal to the predetermined stabilized main bus voltage VB.
9. The shunt part n-raare-ki 3 for v2 with
)'s output current is determined.

Shunt electrician SH determined by Takumi = Technique and +ISR is the intermediate tamp (4) Kara control pass line (flowing to the sword).

It is supplied to the shunt circuit (8). In the diagram of Figure 2.

The part surrounded by V1+V2 and Δ is the satellite's load power.The shaded part is the surplus current consumed by the shunt circuit.

Figure 2 (') V+, ' 2. VBUS, ■1. I'2
+”SH correspond to those in FIG.

During the negative period or when the output of the solar array (1) is lower than the power consumption of the satellite, power is supplied from the power source αυ.

In the configuration shown in Fig. 1, a boost converter az is used to stabilize the main bus voltage to be approximately equal to the main bus voltage during sunshine even when power is supplied from the battery συ.Boost converter (12) The operating region of is provided so as not to overlap with the operating region of the shunt regulator, and when the error signal from the error amplifier (9) is in the operating region of the boost converter (121), the error signal causes the boost converter u2 to The bus voltage is stabilized by adding the difference between the battery voltage and the bus voltage.

FIG. 3 shows the current and voltage changes of the power supply shown in FIG. 1 during the satellite's decay period. Figure 3 (
a) is the positional relationship between the two satellites, the earth, and the sun, and the sunlight
It shows the relationship between the penumbra and penumbra of an eclipse. Figure 3 (b
) shows the current change of the power supply device during the two-meal period, and FIG. 3(c) similarly shows the voltage change. As shown in Figure 3(C), in the conventional configuration, the shunt part solar array (3
) output voltage v2 is.

It temporarily increases during the eclipse penumbra and after-eclipse penumbra.

This is because the two satellites enter the penumbra, and as the amount of sunlight decreases, the output current (short circuit current) of the solar array (1) decreases, and the output of the solar array (1) falls below the supply limit for the satellite load (131). Then, the shunt part solar array (
3) Output voltage ■2754 r solar array (1)
When the voltage falls below the lower limit operating point, which is determined by , a voltage increase occurs. If it enters the penumbra, there is no output from the solar array (t1), so the output voltage of the solar array (1),
The output current becomes zero.

Since the output voltage of a solar cell is inversely proportional to temperature, the output voltage of a solar array increases with the length of time in the eclipse. Therefore, after the satellite of time comes out of the wooden carving, the 9th eclipse is in the penumbra, so the amount of sunlight is low and the shunt regulation function is not working at all. Therefore, the output voltage of the shunt solar array (3) is approximately equal to a very large open circuit voltage, resulting in a lifetime voltage increase.

As the sun approaches, the output of the solar array (1) increases, and the shunt regulation function begins to work, resulting in an output voltage (2) determined by the relationship as shown in FIG. Particularly in the penumbra after the second eclipse, the voltage may be lower than the main bus voltage VBUS, as shown by the dotted line in Figure 3 (C), depending on the temperature conditions of Saugebrae (1), the temperature percentage of the solar cell, the load conditions, etc. The rise may become large, causing a negative effect on the non-shunt area.

Generally, when a solar array is reverse biased, stress is applied to some of the solar cells due to variations in the characteristics of the solar cells, causing the solar cells to generate heat, causing hollow spots and dou spots, and modules in parallel stages. If there is an oven failure force in one cell of the cell, the other cell will have a negative force).

As a result of further increasing it, high heat generation may occur, and in some cases, the interconnector may melt.

This may cause a problem in which output cannot be obtained from the module.

Therefore, in the configuration of the conventional shunt regulator shown in FIG. However, there is a drawback in that a reverse bias is added to the solar cell, which may cause stress on the solar cell and cause a failure.

This invention was made in order to improve these drawbacks, and is an artificial satellite that prevents the non-shunt part solar array (2) from being reversed against the rise in 'αL pressure of the shunt part solar array (3). It provides a power supply device.

An embodiment of the present invention shown in FIG. 4 will be explained below. The numbers (1) to 0 in the Nageme diagram are the same as the conventional structure shown in FIG. In the figure, (14) is a Zener diode,
One tap (4) is connected to the shunt part solar array (3) and the solar array 11. The Zener voltage vzll-1l'2 of the Zener diode (3) is set higher than the maximum operating voltage of the shunt unit nuller array (3) during sunlight,
Also, use a voltage lower than the main bus voltage.

With this configuration, during one day of sunshine,
Since the Zener voltage of the Zener diode circuit α is always higher than the operating voltage of the shunt solar array (3), the current generated by the shunt solar array (31-&- et al.) flows into the Zener diode circuit 04. Instead, the same seat regulator function as before is performed. When the shunt regulator function stops working in the eclipsed penumbra.

When the shunt regulator function is not yet working in the penumbra after the eclipse, the output voltage of the shunt element at the intermediate tap (4) increases due to the Zener voltage VZ of the Zener diode I. , any more than that is clipped by the Zener diode, so it does not rise, and no reverse bias is applied to the non-shunt solar array (2).

It's a luxury in the case of the penumbra and the wood carving.

Power is supplied to the satellite load (I3) from batch IJ (1,1
), so it does not affect the power supply function during two meals.

Therefore, the voltage change shown in FIG. 2 (fc) in FIG. 3 can be improved as shown in FIG.

For 1 or more, connect the Zener diode α (A) with an intermediate tap (
In 4), the shunt section was connected in parallel with the solar array (3), but the present invention is not limited to this. A similar effect can be obtained by connecting in parallel instead of the intermediate tap (4).

1 and 2 For the sake of explanation, the configuration with the boost converter α2 has been described above, but even in a configuration in which the boost converter α is removed, the Zener voltage of the Zener diode [14) can be changed to the batch 'J [1υ of It goes without saying that the present invention can be applied as long as it can be set lower than the bus voltage which depends on the output voltage and higher than the operating voltage of the shunt array (3) during sunlight. Although the partial shunt regulator system has been described in the past two or more, the present invention is not limited to this, and may be applied to a shunt regulator system in which a shunt circuit is connected between the solar array (1).

° As described above, in the satellite power supply device according to the present invention, in contrast to the shunt regulator power supply system in which a shunt circuit is connected in the middle of the solar array, a Zener diode is connected in parallel to the shunt part of the solar array. The switching on and off has the effect of preventing the voltage of the solar array in the shunt section from rising and preventing the solar array from being biased in the non-shunt section, thereby preventing stress from being applied to the solar cell. Although it has a simple configuration, such as being able to be used by adding it to a power supply, its practical effects are extremely large.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of a power supply system for a satellite using a shunt regulator, in which a shunt circuit is connected in the middle of a conventional solar array; Figure 2 is an explanatory diagram of the function of the shunt regulator; Figure 3 is for one meal. FIG. 4 is a diagram showing the characteristics of a conventional satellite power supply device, and FIG. 4 is a schematic configuration diagram of an embodiment of the device of the present invention. FIG. 5 is a voltage characteristic diagram during the eclipse. In the figure, (1) FL-T solar array, (2) non-shunt solar array, (3) shunt solar array, (4) intermediate tap, (5) main pass line, (
6) is the return path line, +7114 control path line, (8) is the shunt circuit, (9) is the error amplifier, ue is the shunt driver, α1) is the battery,
(I2 is the boost converter, (131 is the satellite load,
(I4) is a Zener diode. Note that in FIGS. 2A and 2B, corresponding parts of the same cavities are designated by the same reference numerals. Agent Masuo Oiwa

Claims (1)

[Claims] A solar array that converts solar energy into electricity is used as the primary power source, and a shunt circuit is connected between the solar arrays to stabilize the voltage in the middle of the main path line that supplies power from the solar array to the satellite load. In a power supply system for an artificial satellite using a shunt regulator system, in which the surplus power of the shunt solar array of the solar array connected to the circuit is consumed in a shunt circuit, the voltage is lower than the main bus voltage, and the voltage of the shunt solar array is lower than the main bus voltage. A power supply device for an artificial satellite, characterized in that a Zener diode having a Zener voltage higher than the maximum operating voltage of the antenna is connected in parallel to the shunt unit array.