JPH02193539A - Power source device - Google Patents

Abstract

PURPOSE:To prevent the overdischarge of a storage battery by a method wherein it is decided that a solar cell is shaded from the sun and a load is limited when a value, detected by a solar array current monitor, is smaller than a threshold value and another value, detected by a discharging current monitor, is larger than the threshold value. CONSTITUTION:The output current of a solar cell 1 is supplied to a load 8 through a solar array current monitor 9 and charges a storage battery 2 by a charger 6 when the output capacity has surplus power. When the output is short, electric power is supplied to the load 8 from the storage battery 2 through a discharging current monitor. A shade decider 11 is provided with an internal reference power source 12 and outputs a threshold value. When the output current is compared with the telemetry signal of the current monitor 9 in a comparator 13 and a significant level reducing signal is outputted to an exclusive logical adder 15 when the output current is lower than the threshold value. On the other hand, the output current is compared with the telemetry signal of a current monitor 10 in another comparator 14 and a significant level increasing signal is outputted to the exclusive logical adder 15 when the value of the current is higher than the threshold value. Simultaneously with the input of the significant signal, a load lightening command is outputted. According to this method, the overdischarge of the battery can be prevented automatically.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention supplies power to a load from a solar cell during sunshine, and also charges a storage battery with power.

In a power supply device for an artificial satellite, etc. that supplies power to a load by discharging a storage battery in the shade, it automatically disconnects unnecessary loads in the shade to reduce the burden on the storage battery, and automatically restarts the disconnected load when the sun comes out. The present invention relates to a power supply device having shade determination means that outputs a signal for connection.

[Conventional technology]

Figure 2 is a configuration diagram of a conventional power supply device for an artificial satellite, etc., with loads connected. (l) is a solar battery, (2) is a storage battery, (
3) is a first diode whose anode is connected to the output terminal of the solar cell +11, and whose cathode constitutes a power supply bus. (41 is a second diode whose cathode is connected to the cathode of the first diode (3),
(51 is between the anode of the first diode (3) and the return line (hereinafter referred to as RTN)
) is connected in parallel with the shunt device that consumes the surplus power generated by the solar cell +11.

(61 is a charger connected between the power supply bus and the storage battery (2) to charge the storage battery (2) during sunshine hours.

(7) is a capacitor bank connected between the power supply bus and the RTN, and (8) is a load, the amount of which is set by a command from the ground station.

(9) is a solar array current monitor that detects the current level flowing into the stain source bus through the first diode (3), converts it into a telemetry signal, and sends it out; αG represents the second diode (4) and the storage battery. (2) is a discharge current monitor that is connected between the storage battery (2) and the second diode (4) and detects the discharge current flowing out from the storage battery (2) to the power supply bus, converts it into a telemetry signal, and sends it out. . The operation of the conventional power supply device will be described in detail below.

During sunshine, the power generated by the solar cell (11) is supplied to the load (8) via the first diode (3).
A part of the surplus power generated by the il is converted by the charger (61) and becomes charging power for the storage battery (2), and the remaining power is consumed by the shunt device (5). The voltage (7) (hereinafter referred to as pass voltage) is stabilized to the shunt voltage vSHNT.

The above load (8) is the load reduction command C8 from the ground station.
Normally, the power required for in-orbit services is consumed within a range that does not exceed the power generated by the solar cell (1), but in rare cases the power consumption by the load (8) exceeds the power consumption above. In some cases, the power generated by the solar cell (1) may be exceeded, and in this case, the power consumed by the load (8) is supplemented by discharging the storage battery (2).

In the shade, the power generated by the solar cell (1) stops, so the power supply to the load (8) is entirely provided by the discharge of the storage battery (21) via the second diode (41).

For the purpose of reducing the load amount by limiting the allowable discharge amount of the storage battery (2), the unnecessary loads that do not perform on-orbit service in the shade of the load (8) are subject to load reduction command C.
E is disconnected from the above power supply bus.

The solar array current monitor (9) converts the current consumed by the load (8) into the charger (61) and becomes the charging power for the storage battery (2). The sum of the necessary currents is detected, converted to telemetry signal equipment, ATLM, and sent to the ground station, and the discharge current monitor α. detects the current flowing into the power supply bus, converts it into a telemetry signal IDCHTLM, and sends it to the ground station.

Regarding the operation of the power supply system described above, the following relational expression holds true for #ISATLM and IDCHTLM.

ISATLM in sunlight > 0 (11 ISATLM in shade ” O and IDCHTLM >
O (21 [Problem to be Solved by the Invention] When disconnecting the load (8) that is unnecessary in the shade, conventionally the telemetry signal of the solar array current monitor (9) is connected to the A'TLM and the discharge current. From the telemetry signal of monitor αυ, CHTLM is observed at the ground station, and according to the telemetry signal ISATLM, the normal current generated at the solar lightning pond (11) becomes sufficiently small and the telemetry signal IDCHT is detected.
A human determines that the storage battery (2) is discharging due to the LM.2 A human recognizes that the storage battery (2) has shifted to a shaded state, and a human determines that the load (8) is disconnected from the unnecessary load. C load reduction commands were being sent to the ground station.

However, this method requires that the ground station can always communicate with the satellite, such as with a geostationary satellite.For low-orbit satellites, such as single-orbit satellites, there are many times when it is not possible to communicate with the ground station, and the allowable discharge of the storage battery in the shade is Due to capacity limitations, there were issues such as the inability to effectively use the electricity generated by solar cells during a single day of sunshine.

The present invention was made in order to solve the above-mentioned problems, and an object of the present invention is to provide a configuration of a power supply device that automatically determines a shaded state and sends a load reduction signal to a load.

[Means to solve the problem]

The power supply device according to the present invention uses a telemetry signal of a solar array current monitor and a telemetry signal of a discharge current monitor as input signals, and serves as an internal reference power supply.

Consists of two comparators that compare the levels of the internal reference power supply output signal and the IJ flaw signal (each telemeter), and an exclusive OR adder that outputs a load reduction signal only after receiving significant signals from the two comparators. This is a device that adds a shade determination device to the conventional power supply device.

[Effect]

The power supply device according to the present invention operates in a shaded state when the telemetry signal of the solar array current monitor is smaller than the threshold value generated by the internal reference power source, and when the telemetry signal of the discharge current monitor is larger than the threshold value generated by the internal reference power source. It determines that there is a load on the load and outputs a load reduction signal.

〔Example〕

FIG. 1 is a block diagram of a power supply device connected to a load showing an embodiment of the present invention. fi, +11 to αG are completely the same as the conventional components.

(2) is a shade determination device, az is an internal reference power supply, 3 is a first comparator, (141 is a second comparator, and α is an exclusive OR adder.

Examples of the present invention will be described in detail below.

The first comparator α3 is connected to the telemetry output terminal of the solar array monitor (9) and the output terminal of the internal reference power supply a'a, and is connected to the telemetry output ISATLM of the solar array current monitor (9) and the internal reference power supply When the output vREF of t12 is compared and ISATLM<vREF, the first comparator fi3 sends a significant level reduction signal to the exclusive OR adder αta.

The second comparator α4 is connected to the telemetry output terminal of the discharge stream monitor αG and the output terminal of the internal reference power supply fi3, and is connected to the telemetry output terminal of the discharge stream monitor αG.
DCHTLM and the output vREF of the above internal reference power supply a'a
When IDCHTLM>VREF, the second comparator σ4 sends a significant level increase signal to the exclusive OR circuit α9.

The exclusive OR adder fis is connected to the first comparator 03.
and the output terminal of the second comparator α,
The level reduction signal from the first comparator a3 and the second
The exclusive OR adder αS outputs a load reduction signal to the load (8) only after simultaneously receiving two significant signals including the level increase signal from the comparator αI.

During sunshine, if the power of the load (8) is smaller than the power generated by the solar cell (1), then the output of the discharge current monitor aυ. Since HTLM is zero, equation (4) is not satisfied. When the power of the load (8) is larger than the power generated by the solar cell fil during sunshine.

Since there is a discharge from the storage battery (2), from the output of the discharge current monitor +11. HTLM must be a positive value (4)
The formula may be satisfied. However, in this case, all the current generated in the solar cell (1) flows into the load +81, so the output IS of the solar array current monitor (9)
ATLM must be a fairly large positive value, and the output of the internal reference power supply aZ can be selected to be small (3).
It never satisfies the formula.

Therefore, since Equation 31 and Equation 41 are never satisfied at the same time during sunshine, the load reduction signal is not output from the shade determiner αV to the load (8).

In the shade, the output of the solar cell +11 is zero, so the output ISATLM of the solar array current monitor (9) is also zero, satisfying equation (3). At this time, the above load (8
), the storage battery (2) is discharging and supplying power, so the output of the discharge current monitor +11 is I DCHTL.
M takes a fairly large positive value υ, and formula (4) is satisfied by selecting the output VREF of the internal reference power supply α2 to be small. Furthermore, if vREF is set to zero, the simultaneous establishment of equations (3) and (4) is nothing but equation (2).

Therefore, the output "REF t" of the internal reference power supply (1z)
If it is set to an appropriately small value, equations (3) and (4) can only be satisfied at the same time when it is in the shade.It is possible to determine whether it is in the shade or not, and at the same time, the amount of load can be controlled.

In the above embodiment, the case where the load on the power supply system of an artificial satellite, etc. is reduced during one day in the shade has been described.

An automatic activation function of a load such as a heater used in the shade may be used, and the same effect as the above embodiment can be achieved.

〔Effect of the invention〕

As described above, the power supply device according to the present invention has a terminal for inputting the output signal of the solar array current monitor and the output signal of the discharge current monitor, and has a terminal that is smaller than the threshold value at which the output signal level of the solar array current monitor becomes. determining that the output signal level of the discharge stream monitor is greater than a threshold level;

A shade detector that outputs a load reduction signal to the load has been added, so the power generated by the solar cells can be effectively used during sunshine.When it is in the shade, it is determined that it is in the shade and the unnecessary load is automatically removed. It has the advantage that it can be disconnected to limit the amount of discharge from the storage battery.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a power supply device connected to a load showing an embodiment of the present invention, and FIG. 2 is a configuration diagram of a conventional power supply device connected to a load. In the figure, (1) is a solar cell, (2) is a storage battery, +
31 (41 is a diode, (5) is a shunt device, (
6) is a charger. (7) is the capacitor bank, (8) is the load, (9) is the solar array current monitor, aυ is the discharge current monitor, αB is the shade judge, +13 is the internal reference power supply, α3 (141 is the comparator, aS is exclusive) It is a logical summator. Note that the same symbols in the two figures indicate the same or equivalent parts.

Claims (1)

[Claims] a solar cell, a shunt device connected between the output terminal of the solar cell and a return line, a first diode having an anode connected to the output terminal of the solar cell, and a shunt device connected in series with the cathode of the first diode. a solar array current monitor that is connected and whose output end constitutes a power bus; a charger and a storage battery that are connected in series between the power bus and the return line; a second diode whose cathode is connected to the power bus; and the charger. and a discharge current monitor connected between the connection point of the storage battery and the anode of the second diode,
In a power supply system consisting of a power supply device and its load, which is composed of a power supply bus and a capacitor bank connected between a power supply bus and a return line, the detection signals of the solar array current monitor and the discharge current monitor are input, and the detection signals of the solar array current monitor are inputted. When the detection signal is smaller than a certain threshold and the detection signal of the discharge current monitor is larger than a certain threshold, it is determined that the area is in the shade, and a load reduction signal is sent to the load to control the load on the power supply system. A power supply device characterized by being provided with a shade determination device.