JPS634358B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in solar power generation devices that are used, for example, in artificial satellites and obtain electric energy from light energy.

As is well known, solar power generation devices that obtain electrical energy from light energy have been developed. Figure 1 is an example of a partial shunt method in which only the lower array of the solar cell circuit is shunted.
1 to 14 are solar cell circuits. These solar cell circuits 11-14 are composed of upper arrays 11a-14a and lower arrays 11b-14b, and upper arrays 11a-14a and lower arrays 11b-14
b are connected in series. This upper array 11a to 14a includes blocking diodes 1.
5 to 18 anodes are connected respectively.
The cathodes of the diodes 15 to 18 are grouped together and connected to the lower arrays 11b to 14b via a load 19 such as a secondary battery, for example. Therefore, in the solar cell circuits 11-14, the upper arrays 11a-14a and the lower arrays 11b-14b are connected in series and parallel to the load 19. Also,
An error voltage detector 20 is connected in parallel to the load 19, and the voltage fluctuation (excess power) of the load 19 is detected by this detector 20. This detector 20
The output signal of is amplified by a shunt drive circuit 21 composed of, for example, a transistor amplifier. The output signal of this drive circuit 21, that is, the shunt drive signal is a control circuit that sequentially operates a shunt circuit, which will be described later.
5. Of these, the diode circuit 22
consists of a diode 22 ₁ , and the diode circuit 2
3 consists of a series circuit of diodes 23 ₁ and 23 ₂ . Further, the diode circuit 24 is made up of a series circuit of diodes 24 ₁ , 24 ₂ , 24 ₃ , and the diode circuit 25 is made up of a series circuit of diodes 25 ₁ , 25 ₂ , 25
It consists of _3,25,4 series circuits _. However,
The shunt drive signal controls conduction of the diode circuits 22-25 according to the signal level, and is supplied to the control signal input terminal _C1 of the shunt circuits 26-29, respectively. This shunt circuit 26,
27, 28, and 29 are each composed of a transistor Tr and resistors R ₁ , R ₂ , and R ₃ as shown in FIG. That is, one end of resistor _R1 is connected to the transistor
It is connected to the emitter of the transistor Tr, and one ends of the resistors R ₂ and R ₃ are connected to the base of the transistor Tr. Further, the other end of the resistor _R3 is connected to the control signal input terminal _C1 , and the other ends of the resistors _R1 and _R2 are each connected to the ground terminal _C2 . Furthermore, the collector of the transistor Tr is connected to the terminal _C3 .
Therefore, these shunt circuits 26, 27, 28,
The ground terminals _C2 of 29 are collectively connected to the lower array 11b.
~14b, and the terminal _C3 is connected to the upper array 11a~14a and the lower array 11b~1, respectively.
4b are connected to the connecting portions _P1 to _P4 .

In the above configuration, the solar cell circuit 1 is connected to the load 19.
1 to 14, for example, if excess power is supplied, this is detected by the error voltage detector 20. This detector 20 outputs a signal proportional to the excess power, and this output signal is used by the shunt drive circuit 2.
After being amplified by 1, the diode circuit 22-2
5. This diode circuit 22-25
are conducted sequentially starting from the circuit with the least number of diodes,
Accordingly, the shunt circuits 26 to 29 are sequentially controlled to be conductive. However, solar cell circuits 11 to 14
A shunt current is drawn from the lower arrays 11b to 14b, the output power of the solar cell circuits 11 to 14 is controlled, and the voltage supplied to the load 19 is held constant.

In addition, the shunt circuit 2 that started the shunt operation
6 to 29, the power consumption increases as the drive signal increases, and the power of the lower arrays 11b to 14b of each solar cell circuit 11 to 14 is consumed thereby. Further, when the drive signal becomes higher, the short-circuit current of the solar cell circuits 11 to 14 flows through the shunt circuits 26 to 29, the voltage of the solar cell circuit breaks down, and the power consumption becomes minimum. At this time, solar cell circuits 11 to 1
The diodes 15 to 18 of No. 4 are put into a reverse bias state, and power supply to the load 19 is stopped.

Next, the above operation will be further explained for only the solar cell circuit 11. The voltage-current characteristics of the array 11a and the lower array 11b are shown in FIGS. 3a and 3b, respectively. Here, if the output current i _u of the upper array 11a and the voltage across both ends are v _u , then
The output current of the lower array 11b is the output current of the upper array 11a.
output current i _u and shunt current of shunt circuit 29
It is a composite of i and _s . Therefore, load 1
The voltage across the terminal 9 is obtained by subtracting the voltage drop v _d of the diode 25 from v _u +v _l , and this value is always controlled to be constant by the shunt circuit 29 and the like.

Further, FIG. 4 is a diagram showing the relationship between the shunt drive signal and the shunt current, and shows the relationship between the shunt drive signal and the shunt current.
~29, the shunt operation starts when the shunt drive signals (voltage levels) are respectively v ₂₆ , v ₂₇ , v ₂₈ , and v ₂₉ , and the total shunt current i _T increases linearly with respect to the shunt drive signal. It shows how to do it. However, since the operating points of the shunt circuits 26 to 29 are different as described above, if the operating points change due to temperature changes, the shunt circuits 26 to 29
6-29 Overlapping or discontinuing mutual operations occur, and the total shunt current i _T has the disadvantage that it does not increase smoothly at the handover point. For this reason, the power control operation becomes unstable, causing a problem that it becomes difficult to supply constant power to the load 19.

This invention was made based on the above circumstances, and by operating the succeeding shunt circuit at a low level while the preceding shunt circuit is operating, the handover operation between the preceding shunt circuit and the succeeding shunt circuit is carried out smoothly, and the load is reduced. The present invention provides a solar power generation device that can supply stable power.

An embodiment of the present invention will be described below with reference to the drawings. Incidentally, the same parts as in FIG. 1 are given the same reference numerals, and the description thereof will be omitted.

In FIG. 5, the feature of the present invention is that the control signal input terminals of shunt circuits 26 to 29
A resistive element, which serves as a current limiting element, between each _C1 ,
For example, resistors 30, 31, and 32 are provided. As a result, for example, when the diode 22 ₁ of the diode circuit 22 becomes conductive, the shunt circuits 27 and 2 become conductive due to the operation of the shunt circuit 26.
8 and 29 are sequentially operated at a low level by the conduction current of the diode 22 ₁ flowing through the resistors 30, 31 and 32. Therefore, since the shunt circuits 26 to 29 start operating at different operating levels at the same time, even if the operating point changes due to temperature change, the operations of the preceding shunt circuit and the subsequent shunt circuit can be smoothly taken over. , the total shunt current i _T also increases linearly at the time of the takeover operation. Incidentally, FIG. 6 shows the relationship between the shunt drive signal and the shunt current at this time, and at the same time the shunt current i 26 flows in the preceding shunt circuit 26, the shunt current i ₂₆ flows in the subsequent shunt circuits 27, 28, 2.
9 shows that shunt currents i ₂₇ , i ₂₈ , and i ₂₉ flow in sequence at low levels.

According to the above embodiment, the shunt circuits 26-2
The control signal input terminals _C1 of 9 are connected by resistors 30, 31, and 32, respectively, and while the preceding shunt circuit is operating, the subsequent shunt circuits are sequentially operated at a low level. Therefore, even if the operating points of the shunt circuits 26 to 29 change due to temperature changes, the operations of the preceding shunt circuit and the subsequent shunt circuit are smoothly taken over, so that duplication or intermittent operation between the shunt circuits is avoided. This has the advantage that the total shunt current i _T increases smoothly at the takeover point. Moreover, since the power control operation is stable, it is possible to supply constant power to the load 19.

Next, other embodiments of the invention will be described. Incidentally, the same parts as in FIG. 5 are given the same reference numerals, and the description thereof will be omitted.

In FIG. 7, heat-sensitive elements such as thermistors 40, 41, and 42 are used in place of the resistors 30, 31, and 32 as resistance elements serving as current limiting elements. That is, the thermistors 40, 41, and 42 are provided _between the control signal input terminals C1 of the shunt circuits 26 to 29, respectively, and the thermistors 40, 41, and 42 are transistors provided in the shunt circuits 26, 27, and 28, respectively. It is designed to operate based on temperature changes in the transistor.

With the above configuration, it is possible to sequentially operate the subsequent shunt circuits at a low level while the preceding shunt circuit is operating, similar to the embodiments described above. Moreover, since the thermistors 40, 41, and 42 detect and compensate for variations in the operating point due to temperature changes in the preceding shunt circuit, it is possible to carry out the handover operation between the preceding shunt circuit and the succeeding shunt circuit even more smoothly. Therefore, it is possible to perform even more stable power control operation.

It should be noted that the present invention is not limited to the embodiments described above, and it goes without saying that various modifications can be made without departing from the gist of the invention.

As detailed above, according to the present invention, by operating the succeeding shunt circuit at a low level while the preceding shunt circuit is operating, the handover operation between the preceding shunt circuit and the succeeding shunt circuit is performed smoothly, and the load is stabilized. It is possible to provide a solar power generation device that can supply electric power.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing an example of a solar power generation device, Fig. 2 is a circuit diagram showing a part of Fig. 1, and Figs. 3 a, b, and 4 are for explaining the operation of Fig. 1. FIG. 5 is a configuration diagram showing an embodiment of the solar power generation device according to the present invention, and FIG.
FIG. 7 is a diagram showing another embodiment of the present invention. 11-14...Solar cell circuit, 19...Load,
20...Error voltage detector, 22-25...Diode circuit, 26-29...Shunt circuit, 30-
32...Resistance, 40-42...Thermistor.

Claims (1)

[Claims] 1. A solar cell circuit in which multiple sets of solar cell arrays each consisting of a plurality of solar cells connected in series are connected in parallel, a load to which the power generated by this solar cell circuit is supplied, and fluctuations in the load voltage of this load. an error voltage detector for detecting the error voltage detector; a shunt drive circuit to which the error output of the error voltage detector is supplied and generates a shunt drive signal with a level proportional to the error output; and a shunt drive circuit connected to each of the solar cell arrays. each of which consumes the power generated by the connected solar cell array when conductive due to the application of the shunt drive signal, and the input ends of the shunt drive signal located adjacent to each other are connected via a resistive element. A solar power generation device equipped with a plurality of shunt circuits.