JPH03224898A - 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] [Industrial Application Field] The present invention converts the stress generated by the earth's gravitational force acting from the satellite center of mass toward the earth-directing surface and the centrifugal force acting from the counter-earth-directing surface into electrical energy. By supplying the load along with the solar panel output.

This invention relates to an artificial satellite that increases the power generated by the satellite system and reduces the depth of discharge of the battery during shade.

[Prior Art] Figure 3 is an external view showing the structure of a conventional satellite, and Figure 4 is a block diagram showing a power control system using a partial shunt regulator system, which is a typical power control system for conventional satellites. It is a diagram. In the figure, (1) is the east panel that is the satellite structure, (2) is the west panel that is the satellite structure, (
3) is the south panel that is the satellite structure, (4) is the north panel that is the satellite structure, and [5] is the earth-oriented panel that is the satellite structure.

(6) is the satellite structure's anti-earth orientation panel, (7) is the communication antenna attached to the earth orientation panel (5), (8) is the solar battery paddle that holds the solar cells, (9)
) is the load of mission equipment, heaters, etc.

(lO) is the boost converter that controls the battery voltage according to the control current from the error amplifier, (11) is the battery that supplies the shade special power of the load (9), and (12) is the power consumption of the load (9) or an error amplifier that outputs a control current that corrects fluctuations in power output from the solar panel;
(13) is a shunt assembly that shunts a part of the output current of the solar panel according to the control current and releases it as thermal energy; (14) is a backflow prevention that prevents the shunt current flowing through the shunt assembly (13) from flowing backwards; The diode (15) is a solar panel that supplies solar power to the load (9).

Conventional satellites were constructed as described above, and had a structural structure in which panels of aluminum honeycomb structure were combined, as shown in Figure 3. The power control system is configured as shown in Fig. 4, and when the output power of the solar panel (15) exceeds the power consumption of the load (9) and the -order power supply voltage fluctuates, the error amplifier ( The control current from 12) is compared with the reference voltage and amplified to the shunt assembly (13).
sent to. Here, the shunt assembly (13) shunts a part of the output of the solar panel (15) according to the control current by the function of the transistor as a rectifying element, passes it through an internal pure resistance, and releases it as Joule heat. Therefore, the negative power supply voltage is stabilized.

Conversely, when the power consumption of the load (9) exceeds the output power of the solar panel (15) and the primary power supply voltage fluctuates, the control current from the error amplifier (12) is transferred to the boost converter (
10). The boost converter (10) performs pulse width control in accordance with the control current so as to compensate only for the difference obtained by subtracting the output voltage of the battery (11) from the satellite bus voltage.
-The secondary power supply voltage is stabilized.

[Problems to be Solved by the Invention] As described above, conventional artificial satellites have supplied power to loads using solar panels and batteries. Therefore, in satellite system design, when it becomes clear that the required power will increase due to factors such as an increase in the number of mission equipment systems or an increase in the power consumption of individual components, a method has been taken to increase the mounting area of the solar cells. However, in order to increase the mounting area of solar cells, it is necessary to increase the size of the paddle that holds the solar cells, which affects mechanical compatibility with the rocket during launch, and specifically the interface with the fairing. The challenge was to give. Also, when the power supply from the solar panel ceases in the shade, power is supplied to the load by the battery via the boost converter, but there is a limit to the power that the battery can supply based on the battery capacity and maximum depth of discharge. . When designing a satellite system, we take into consideration the power requirements of the mission equipment, the battery capacity, maximum depth of discharge9, weight, footprint, and permissible environmental conditions, and ensure that the system is electrically, mechanically, and thermally stable. However, in broadcasting and communication satellites that carry a large number of high-power-consuming devices such as high-output amplifiers and traveling wave tubes as part of their missions, the power load on the battery is a design issue. As a result, the battery's maximum depth of discharge in the shade becomes a large value that is just on the edge of the allowable limit, resulting in a problem that the life of the battery in orbit is shortened.

The present invention was made in order to solve this problem, and the stress generated by the earth's gravitational force acting on the earth-oriented side from the satellite center of mass (center of gravity) and the centrifugal force acting on the counter-earth-oriented side is absorbed by each of the structures. By converting the energy into electrical energy using piezoelectric ceramics in the panel and supplying it to the load along with the solar panel output, we aim to create an artificial satellite that can increase the power generated by the satellite system and keep the battery discharge depth to a minimum in the shade. purpose.

[Means for solving the problem] The artificial satellite according to the present invention has a center of mass (center of gravity) of nine artificial satellites.
The four panels of the structure, the east panel, the west panel, the south panel, and the north panel, are equipped with stress generated by the earth's gravitational force acting in the earth-oriented direction and the centrifugal force acting in the counter-earth direction. By converting it into electrical energy using piezoelectric ceramics and supplying it to the load along with the output of the solar cell panel, there is no need to increase the mounting area of the solar cell (it increases the power generated as a satellite system and keeps the depth of discharge of the battery in the shade small). .

[Operation] In the present invention, the earth's gravitational force, which is proportional to the length of the center of gravity and the mass of the satellite, acts on the center of mass (center of gravity) of a satellite orbiting the earth in the direction of the earth orientation plane. Further, a centrifugal force proportional to the length of the double center of gravity and the orbital speed acts on the center of mass (center of gravity) of the satellite in the direction opposite to the Earth's directional plane. this,
Each force is applied as stress to each piezoelectric ceramic provided in the east panel, west panel, south panel, and north panel of the satellite structure. This stress induces an amount of electricity (charge) inside the piezoelectric ceramics provided on the earth-oriented surface side and the piezoelectric ceramics provided on the counter-earth-oriented surface side, producing opposite potential differences in each. Since ceramics with this potential difference are connected by lead wires and electrically connected to the solar panel, stress (
Electric power proportional to gravity (gravitational force, centrifugal force) is supplied to the load along with the output power of the solar panel.

[Embodiment] Fig. 1 is an external view showing the structure of an artificial satellite which is an embodiment of the present invention, and Fig. 2 is a block diagram showing the power control system of the artificial satellite which is an embodiment of the present invention. be. In the figure (1
1 to (15) are exactly the same as the conventional device described above, and (16) is the earth-oriented surface side provided on the earth-oriented surface side of the east panel, west panel, south panel, and north panel that are the structure. Piezoelectric ceramics (17) is a piezoelectric ceramic on the anti-earth oriented surface side of the east panel, west panel, south panel, and north panel of the structure.

(18) is the center of mass of a satellite orbiting the earth, (19)
is the earth's gravitational force acting on the earth-oriented surface side of medium mass (18).

(20) is the centrifugal force acting on the anti-earth oriented side of the center of mass 8), and (21) is a lead wire that electrically connects the piezoelectric ceramics. The artificial satellite which is an embodiment of the present invention is constructed as described above, and as shown in FIG. (4) Each panel is equipped with piezoelectric ceramics on the earth-oriented side and the anti-earth-oriented side.

Each piezoelectric ceramic is electrically connected by a lead wire (21) as shown in the block diagram of FIG. As shown in Figure 1, an artificial satellite, which is a spacecraft that orbits the Earth at high speed, has the Earth's gravitational force (
19) comes into play. Also.

A centrifugal force (20) that is proportional to the length from the center and the orbiting speed of the satellite acts on the center of mass (18) in the anti-Earth orientation direction. Each of these forces is applied as stress to the piezoelectric ceramics provided in each panel.

This stress causes piezoelectric ceramics (16
) and the piezoelectric ceramics (17) on the anti-earth oriented surface side, an electric quantity (charge) is induced inside the piezoelectric ceramic (17), and opposite potential differences are generated. Ceramics with this potential difference are connected by lead wires (21) and are electrically connected to the solar panel (15), so they are not affected by stress, that is, earth's gravitational force (19) and centrifugal force (20). Proportional power is supplied to the load along with the output power of the solar panel (15). Stress changes as the satellite orbits at high speed, and the total output power of the solar panel (15) and piezoelectric ceramics changes accordingly, exceeding the power consumption of the load (9), and - When the power supply voltage fluctuates, the error amplifier (12) sends a control current that is compared with a reference voltage and amplified to the shunt assembly (13). Here, the shunt assembly (13) operates as a rectifying element of the transistor to control the solar panel (13) according to the controlled current.
15) and a part of the total output power of the piezoelectric ceramic is shunted and passed through an internal pure resistance, thereby dissipating it as Joule heat. Therefore, the negative power supply voltage is stabilized. On the other hand, as the satellite orbits at high speed, the stress changes, and the total output power of the solar panel (15) and piezoelectric ceramics changes accordingly, falling below the power consumption of the load (9), - When the next power supply voltage fluctuates, the control current from the error amplifier (12) is sent to the boost converter (lO). The boost converter (lO) performs panel width control in accordance with the control current to compensate for only the difference obtained by subtracting the output power of the battery (11) from the satellite bus voltage, and the -order power supply voltage is stabilized.

As described above, the artificial satellite, which is an embodiment of the present invention, is operated by the earth's gravitational force acting on the earth-directing surface side and the centrifugal force acting on the anti-earth-directing surface side with respect to the center of mass of the satellite. By converting the stress applied by the piezoelectric ceramics provided in the panel into electrical energy and supplying it to the load along with the solar cell panel output, the power generated as a satellite system is increased without increasing the solar cell mounting area. ) The depth of discharge of the battery can be reduced.

[Effects of the Invention] As explained above, the present invention converts the force acting from the center of mass of one artificial satellite in the earth pointing direction and the anti-earth pointing direction into electrical energy, which can be supplied to the load along with the output of the solar battery panel. The power generated by the satellite system can be increased without increasing the mounting area of the solar panel.

This has the effect of making it possible to cope with increased power consumption of the load without affecting the fairing interface with the launch vehicle. In addition, it is possible to supply power to the load along with the battery even in the shade when the solar panel is unable to supply power to the load, reducing the electrical load on the battery, which has the effect of reducing the depth of discharge of the battery. This has the effect of contributing to extending the life of the battery in orbit. Furthermore, since the stress applied to the satellite structure is converted into electrical energy, it has the effect of eliminating mechanical stress applied to the satellite body (12).

[Brief explanation of drawings]

FIG. 1 is an external view showing the structure of a satellite showing an embodiment of the present invention, FIG. 2 is a block diagram showing a power control system of a satellite showing an embodiment of the present invention, and FIG. 3 is a conventional FIG. 4 is a block diagram showing a power control system using a partial shunt regulator system, which is a typical power control system for conventional satellites. In the diagram, (1) is the east panel, (2) is the west panel,
(3) is the south panel, (4) is the north panel, (5) is the earth-oriented panel, (6) is the counter-earth-oriented panel, (7)
is a communication antenna, (8) is a solar array paddle, (9) is a load, and (10) is a boost converter. (11) is the battery, (12) is the error amplifier, (1
3) is the shunt assembly, and (14) is the backflow prevention diode. (15) is the solar array paddle, (16) is the piezoelectric ceramic on the earth-oriented side, (17) is the piezoelectric ceramic on the anti-earth-oriented side, (18) is the center of mass, (19)
is the earth's gravitational force. (20) indicates the centrifugal force, and (21) indicates the lead wire. still. Same symbols in each figure. Indicates the same or equivalent part.

Claims (1)

[Claims] The four panels of the satellite structure are the east and west panels, the west panel, the south panel, and the north panel, and the piezoelectric ceramics installed on the earth-oriented west side of each panel and the leads that electrically connect the ceramics on each side. A wire, piezoelectric ceramics provided on the anti-earth oriented surface side of each panel, lead wires that electrically connect the ceramics on each surface, and a solar cell panel that supplies power to the load during sunlight. A battery that supplies power to the load in the shade, an error amplifier that outputs a control current that corrects fluctuations in power consumption of the load or output power of the solar panel and piezoelectric ceramics, and controls the battery voltage according to this control current. From a boost converter, a shunt assembly that shunts a part of the output current of the solar panel and piezoelectric ceramic according to the control current and releases it as thermal energy, and a backflow prevention diode that prevents the shunt current flowing through this shunt assembly from flowing back. By converting the stress caused by the earth's gravitational force acting from the satellite center of mass toward the earth-oriented side and the centrifugal force acting from the counter-earth-oriented side into electrical energy and supplying it to the load along with the solar panel output, the solar cell An artificial satellite that is characterized by increasing the power generated as a system without increasing the mounting area and reducing the depth of battery discharge in the shade.