JP2004229439A - Power supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply device that can feed power required by a satellite in abnormality using the other unit of a battery, while one unit is in reconditioning operation, by dividing one battery into a plurality of units, to enable reconditioning operation for each unit. <P>SOLUTION: This power supply device is provided with the battery that comprises the plurality of units for accumulating electrical energy; a battery voltage detection circuit that detects a voltage of each unit of the battery; a reconditioning circuit that charges and discharges the unit, based on an output of the battery voltage detection circuit; and a first switch that is connected to each unit of the battery in series and switches connection to the reconditioning circuit. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a power supply device mounted on a satellite.
[0002]
[Prior art]
The battery used in the satellite power supply is often used only in the shade, and the capacity at the time of discharge is reduced due to the memory effect due to a long service life, a long period of non-use, etc., and the usable capacity is reduced. There are cases. Therefore, in order to restore the capacity of the battery to the originally held capacity, it is necessary to perform a reconditioning operation of once discharging the battery to empty and performing recharging.
[0003]
On the other hand, in particular, a small satellite requires one satellite bus and one battery in some cases because the satellite power supply device is required to be small and low cost. The battery needs to supply power instead of the solar cell when solar light does not enter the solar cell, so that power can be supplied even if the satellite attitude is disturbed due to a malfunction and solar light does not enter the solar cell. Need to be kept.
[0004]
However, in the reconditioning operation, there is a period in which the capacity of the battery is empty, and there is a period in which power cannot be supplied to the satellite. Therefore, the conventional power supply device having only one battery cannot perform the reconditioning operation. there were.
[0005]
[Patent Document 1]
JP-A-3-281497 (FIG. 1)
[0006]
[Problems to be solved by the invention]
In the above-mentioned conventional apparatus, since there is only one battery, the reconditioning operation cannot be performed. If the reconditioning operation is performed using only one battery, there is a period in which the capacity of the battery becomes almost empty.
[0007]
In the event that an abnormality occurs in the satellite during this period and the solar cell loses sunlight, power cannot be supplied from the battery and the satellite loses its function. For this reason, a memory effect occurs in the battery, and even if the capacity of the battery is reduced, the capacity cannot be recovered. Therefore, there is a problem that the capacity that can be taken out from the battery is reduced, and the operation of the satellite must be greatly restricted.
[0008]
SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and divides one battery into a plurality of units, and enables a reconditioning operation for each unit. During the reconditioning operation of one unit, power can be supplied to the other unit in the event of an abnormality required by the satellite.
[0009]
[Means for Solving the Problems]
A power supply device according to the present invention includes a battery including a plurality of units that store electric energy, a battery voltage detection circuit that detects a voltage of each unit of the battery, and discharging of the unit based on an output of the battery voltage detection circuit. A reconditioning circuit that performs charging; and a first switch that is connected in series to each unit of the battery and that switches connection with the reconditioning circuit.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
In FIG. 1, during sunshine, power generated by a solar cell 1 is supplied to a satellite load 3 via a power controller 2. Excess power in which the power generated by the solar cell 1 exceeds the satellite load 3 is shunted to the shunt device 4 by a control signal from the power controller 2. The control signal of the power controller 2 operates to stabilize the voltage supplied to the satellite load 3 and controls the shunt device 4.
[0011]
Although the battery 6 is divided into two or more units, an example shown in FIG. 1 in which the battery 6 is divided into three units will be described for the sake of simplicity.
[0012]
The battery units 6a, 6b, 6c are connected in series by first switches 9a, 9b, 9c and connected to the boost converter 5. When the sunlight does not enter the solar cell 1, the solar cell 1 cannot supply power to the satellite load 3, so that power is supplied from the batteries 6a, 6b, 6c.
[0013]
The output voltages of the battery units 6a, 6b, and 6c are supplied to the satellite load 3 at a predetermined value by the boost converter 5 by converting and stabilizing the voltage. During normal operation of the satellite, the reconditioning circuit 8 is separated from the battery units 6a, 6b, 6c by the first switches 9a, 9b, 9c and does not operate. Bypass diode 11a connected in parallel with battery unit 6a and first switch 9a, bypass diode 11b connected in parallel with battery unit 6b and first switch 9b, and in parallel with battery unit 6c and first switch 9c. Since the connected bypass diode 11c is reverse-biased with the output voltage of each battery unit, no current flows during normal operation.
[0014]
The second switches 10a, 10b, and 10c connected in parallel to the bypass diodes 11a, 11b, and 11c are open during normal operation of the satellite, so that the charging current does not flow from the charging controller 7 during daylight. During the normal operation, the trickle charge current from the charge controller 7 is supplied to the batteries 6a, 6b, 6c.
[0015]
The battery cell voltage detection circuit 12 detects the voltage of each battery unit or each battery cell, and detects whether each battery unit or battery cell is operating normally. The diodes 13 and 14 are used for the purpose of preventing current from flowing backward.
[0016]
Next, during operation of the satellite, when the battery cell voltage detection circuit 12 performs a reconditioning operation of the battery unit 6b on the assumption that a cell voltage is reduced in some cells of the battery unit 6b due to a memory effect. Will be described with reference to FIG.
[0017]
After confirming that power is being supplied from the solar cell 1 to the satellite load 3, the trickle charge from the charge controller 7 is stopped. The first switch 9b is switched to a contact on the reconditioning circuit 8 side. After confirming that the first switch 9b has been switched, the contact of the second switch 10b is closed. After confirming that the contact of the second switch 10b is closed, trickle charging of the charge controller 7 is restarted. In this state, the battery units 6a and 6c resume trickle charging and continue. On the other hand, the battery unit 6b is connected to the reconditioning circuit 8 by the first switch 9b, and is discharged by the discharge resistor 16b by closing the third switch 15b. This discharge is continued until the battery unit 6b is almost empty. After the predetermined discharge is completed, the third switch 15b is opened to stop the discharge.
[0018]
Thereafter, the reconditioning charge controller 17 is operated to charge the battery unit 6b until the battery unit 6b reaches a predetermined charge state. After the predetermined charge is completed, the operation of the reconditioning charge controller 17 is stopped. By this reconditioning operation, it is possible to recover a part or all of the decrease in battery capacity due to the memory effect of the battery cells.
[0019]
After confirming that the operation of the reconditioning charge controller 17 has stopped, the trickle charging operation of the charge controller 7 is stopped again, and the second switch 10b is opened. After confirming that the second switch 10b is open, the contact of the first switch 9b is switched to the boost converter 5 side. Thereafter, by starting the trickle charging operation of the charging controller 7, the battery units 6a, 6b, 6c are connected to the state before the reconditioning operation, and the battery units 6a, 6b, 6c can supply power to the satellite load 3 again. State.
[0020]
During the reconditioning operation of the battery unit 6b, if power cannot be supplied from the solar battery paddle due to a satellite failure and power must be supplied from the battery, the battery units 6a and 6c that are not performing the reconditioning operation are bypassed. It discharges through the diode 11b and supplies power to the satellite load 3 at a voltage stabilized at a predetermined voltage by the boost converter 5.
[0021]
In this way, even in the event of a satellite failure, the battery unit that has failed can be reconditioned without losing the function of supplying power to the satellite. In this embodiment, the case where a plurality of second switches and a discharge resistor are used has been described. However, the same effect can be obtained even when switching is performed by using a set of a second switch and a discharge resistor. I can do it.
[0022]
FIG. 3 is a diagram showing an embodiment of the reconditioning charge controller 17 in the reconditioning circuit 8. After the discharging of the battery unit 6b is completed, the third switch 15b is opened, and the switch operation of the switch control circuit 18 is turned on. By the operation of the switch control circuit 18, a current flows through the primary winding 20 of the transformer 19, and a voltage is induced on the secondary windings 21a, 21b, 21c.
[0023]
Since the first switch 9b has a contact connected to the reconditioning circuit 8 side, it forms a closed circuit with the current control circuit 22b, so that current is supplied from the current control circuit 22b to the transformer battery unit 6b. This current charges the battery unit 6b to a predetermined value.
[0024]
Note that no current flows through the current control circuits 22a and 22c because no load is connected. In this embodiment, the case where one transformer 19 is used has been described, but the same effect can be obtained by using a plurality of transformers.
[0025]
As described above, it is possible to recondition the battery, and it is not necessary to mount a large-capacity battery in advance to reduce the battery capacity, so that the battery can be reduced in size and cost. In addition, since the battery can be reduced in size and its mass can be reduced, a large amount of fuel can be mounted on the satellite, and the life of the satellite can be increased.
【The invention's effect】
According to the present invention, as described above, one battery is divided into a plurality of units, and a reconditioning operation can be performed for each unit. During the reconditioning operation of one unit, it is possible to supply power to the other unit in the event of an abnormality required by the satellite.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of the present invention, and is a diagram showing a normal operation state of a satellite.
FIG. 2 is a view showing an embodiment of the present invention, and is a view showing a reconditioning operation state of one battery unit.
FIG. 3 is a diagram illustrating an embodiment of the present invention, and is a diagram illustrating a detailed example of a reconditioning charge controller.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 solar cell 2 power controller 3 satellite load 4 shunt device 5 boost converter 6a battery unit 6b battery unit 6c battery unit 7 charge controller 8 reconditioning circuit 9a first switch 9b first switch 9c first switch 10a 2 switch 10b 2nd switch 10c 2nd switch 11a bypass diode 11b bypass diode 11c bypass diode 12 battery cell voltage monitor circuit 13 diode 14 diode 15a third switch 15b third switch 15c third switch 16a discharge resistance 16b Discharge resistor 16c Discharge resistor 17 Reconditioning charge controller 18 Switch control circuit 19 Transformer 20 Primary winding 21a Secondary winding 21b Secondary winding 21c Secondary winding 22a Current control circuit 22b Current control circuit 22c Current Control circuit

Claims (4)

A battery including a plurality of units that store electrical energy, a battery voltage detection circuit that detects a voltage of each unit of the battery,
A reconditioning circuit for discharging and charging the unit based on the output of the battery voltage detection circuit,
A first switch connected in series to each unit of the battery and switching connection with the reconditioning circuit;
A power supply device comprising: Solar cells that convert light into electrical energy,
A charge controller that supplies electric energy from the solar cell to each unit of the battery;
A second switch that switches a bypass of electric energy from the charge controller supplied to each unit of the battery;
The power supply device according to claim 1, further comprising: The power supply device according to claim 2, further comprising a diode connected in parallel with the second switch to prevent a current from flowing backward. The power supply device according to claim 1, wherein the reconditioning circuit includes a resistor for discharging the unit.

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