JPH05122866A - Bus voltage controller - Google Patents

Abstract

PURPOSE:To supply power by a stabilized voltage required for a device to be placed of a load and to supply power to be used for a solar cell array in a maximum efficiency in a bus voltage controller for a power source to be used for a spacecraft. CONSTITUTION:The bus voltage controller comprises a solar cell array 1, a shunt circuit 4 for consuming its excess power, a switch 6 for disconnecting a voltage controller 3 and the circuit 4 from a bus line 5, and a bus voltage regulating resistor 7 connected in parallel with a load 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bus voltage control device used as a power supply device for a spacecraft such as an artificial satellite.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 4, a bus voltage control device of this type is supplied to a solar cell array 1 mounted on a spacecraft, a load 2 such as on-board equipment, and a load 2. A voltage controller 3 for detecting surplus power of the solar cell array 1 from the voltage, and a shunt circuit 4 having a transistor control function of shunting the surplus power by the control of the voltage controller 3.
And a floating type battery 22 that stores the electric power of the solar cell array 1. Here, the bus voltage is a system in which the shunt circuit 4 controls the power generated by the solar cell, and the upper limit value of the bus voltage is controlled to a single voltage set in advance.

[0003]

In the above-mentioned conventional bus voltage control device, the upper limit value of the bus voltage is always fixed to a single value, so that various on-board devices use the same bus voltage. Become. Since the voltage value is determined by the mounted device using the component having the minimum withstand voltage, when the device that consumes a large amount of power is mounted, the device can withstand a high input voltage, and Even if the power consumption type is constant, a low bus voltage must be used, and a high output solar cell array is required.

[0004]

A bus voltage control device of the present invention is a voltage for detecting surplus power of a solar cell array from a voltage value of a bus line that supplies the power generated by the solar cell array to a load of a device mounted on a satellite. In a bus voltage control device including a controller and a shunt circuit that divides the generated power by control of the voltage controller, a shunt resistor for adjusting a bus voltage connected in parallel with the load, and the solar cell A switch for turning off the shunt circuit in order to use the array with high efficiency.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an embodiment of the present invention. The bus voltage control device of this embodiment is roughly classified and has two functions. First, as a conventional bus voltage control function, a solar cell array 1 for converting light energy into electric energy
In order to supply the output power of the solar cell 1 to the load 2 of the on-board equipment, which is a load, with the voltage controller 3, the solar cell array 1
The surplus status of the output is detected, and a signal according to the surplus status is sent to the shunt circuit 4, and the shunt circuit 4 consumes the surplus portion of the solar cell array and stabilizes the bus line voltage which is the power supplied to the on-board equipment. .. At this time, the shunt circuit 4 is connected by the switch 6 for connecting to or disconnecting from the bus line 5. Next, in order to use the output of the solar cell array 1 with high efficiency, which is another function, a function of supplying electric power at a voltage higher than a voltage controlled by a shunt circuit called a steady bus voltage will be described. First, one or a plurality of bus voltage adjusting resistors 7 are provided in parallel with a load 2 of an on-board device which is a load of the solar cell array 1. When it is desired to supply the load 2 with a voltage higher than the steady bus voltage, the adjustment resistor 7 is selected according to the output of the solar cell array 1 and connected in parallel to the load 2. The solar cell output changes due to seasonal changes over the years and changes over time due to radiation exposure. FIG. 5 shows an example of the relationship between the solar cell array output characteristics and the load. In FIG. 5, 8 is the array output characteristic in the summer solstice of the early mission life (BOL), 9 is the array output characteristic in the equinox of the BOL, 10 is the output characteristic in the summer solstice of the end of mission life (EOL), and 11 and 12 are for adjustment. Power consumption by the resistor 7, 13 is a curve of power consumption characteristics of the load 2, 1
4 is a power consumption curve obtained by adding 13 and 11, and 15 is 13
This is a power consumption curve obtained by adding 12 and 12. 16 indicates the position of the steady bus voltage, and 17 indicates the high bus voltage line. a, b, and c are the intersections of the array output characteristics of 8, 9 and 10 and the steady bus voltage 16. First, in the steady state, 16 steady bus voltages are set by the operation of the shunt circuit 4 even when the array output characteristics and the load change like 8 to 10, and power is supplied to the on-board equipment of the load 2 at a stable voltage. .. The power supplied at this time is a value obtained by multiplying the current values on the X-axis of a, b, and c and the voltage value on the Y-axis. Next, in order to set the high bus voltage 17 for the purpose of using the solar cell array output with high efficiency (increasing the supply power), the power consumption 13 of the mounted device and the power consumptions 11 and 12 by the adjustment resistor 7 are set. The load is applied to the combined solar cell array 1. In the example of FIG. 5, the load solstice 13 and the adjusting resistor 12 are combined in the summer solstice of the BOL, and the combinations 13 and 11 are the EOL in the equinox of the BOL.
There are only 13 in the summer solstice. The power supply at this time is d,
This is a value obtained by multiplying the current values of e and f on the X-axis and the voltage value of the Y-axis, and the supplied power is larger than when the steady bus voltage 16 is used. Since the output of the solar cell array 1 changes every moment, the point of the high bus voltage 17 is not constant and moves on the array output characteristic, and the voltage becomes the intersection of the array output characteristic at that time and the power consumption curve of the combined load.
2 and 3 are application examples of the embodiment of FIG. 1, there are a plurality of on-board devices that are loads, the load 18 uses a steady bus voltage, and the load 19 is a solar cell at one or all times during the mission life. A case where a high bus voltage is used for the purpose of using the array output with high efficiency is shown. FIG. 2 shows a case in which the load separation switch 20 and the battery changeover switch 21 are provided, and the switch 20 is turned off to temporarily supply the array output to the load 19 at a high bus voltage. Discharge power of the battery 22 is supplied by. 3 (a) and 3 (b) respectively show the load 18 and the load 19 completely separated, and the steady bus voltage stabilized by the shunt circuit 4 is supplied to the load 18 shown in FIG. 3 (a). . To the load 19 shown in FIG. 3B, the switch 21 is operated as necessary to supply electric power at a steady bus voltage or a high bus voltage. FIG. 6 shows the power that can be supplied by the solar cell array when a constant and stable bus voltage is used at all times and when the high bus is used. If the bus voltage is fixed at CV, B
To obtain W power, voltage-current (VI) characteristic 2
3. A solar cell array having a voltage-power (V-P) characteristic 25 is required, but when the array output is used with high efficiency, the V-I characteristic 22 and the V-P characteristic are required to obtain the BW output. A solar array with 23 would be good. In the former case, the power between B and A is consumed as excess power in the shunt circuit.

[0006]

As described above, the present invention includes a switch for turning on / off the bus voltage control function of the conventional shunt circuit and one or a plurality of bus voltage adjusting resistors, thereby providing a stable bus voltage. There is an effect that the mode and the high bus voltage mode, which is also intended to use the solar cell array output with high efficiency, can be properly used.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a block diagram showing an application example of the present embodiment.

FIG. 3 is a block diagram showing another application example of the present embodiment.

FIG. 4 is a block diagram of a conventional bus voltage control device.

FIG. 5 is a characteristic diagram illustrating the present embodiment.

FIG. 6 is an explanatory diagram of power supply for explaining the present embodiment.

[Explanation of symbols]

 1 solar cell array 2 load 3 voltage controller 4 shunt circuit 5 bus line 6, 20, 21 switch 7 adjusting resistor 8 BOL array output characteristic in summer solstice 9 BOL array output characteristic in spring equinox 10 EOL array output characteristic in summer solstice 11, 12 Power consumption of resistor 7 13 Load power consumption curve 14, 15 Added power consumption curve 16 Steady bus voltage line 17 High bus voltage line 18, 19 Load 22 Battery

Claims (2)

[Claims] 1. A voltage controller that detects surplus power of the solar cell array from a voltage value of a bus line that supplies the power generated by the solar cell array to a load of a device mounted on an artificial satellite, and the voltage controller controls the voltage controller to detect the surplus power of the solar cell array. In a bus voltage control device including a shunt circuit that diverts generated power, a shunt resistor for bus voltage adjustment that is connected in parallel with the load,
A switch for turning off the shunt circuit in order to use the solar cell array with high efficiency, and a bus voltage control device. 2. The shunt resistor for adjusting the bus voltage has a function of switching and using at least three kinds of shunt resistors at the beginning of the mission life of the summer solstice and spring equinox and at the end of the mission solstice of the summer solstice. The bus voltage controller according to claim 1.