JPS5815434A - Solar battery power source device - 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 The present invention relates to a solar battery power supply device that uses a solar battery as a power supply source and supplies energy to a load while floatingly charging a storage battery.

In such devices, since the power generation capacity of solar cells differs significantly between sunlight and shade, a storage battery is inserted between the solar cells and the load in order to provide a stable power supply to the load at all times. A conceivable solution is to supply the charging capacity from this storage battery to the load when the power generation capacity of the solar cell decreases.

However, if the solar cell, storage battery, and load are directly connected in parallel in sequence, high voltage will be applied to the Hf battery even after it reaches charge, and there is a risk of overcharging and destruction. be.

One possible method for preventing overcharging of the storage battery is to insert a commonly used constant voltage power supply device between the solar cell and the storage battery.

Such a system will be explained with reference to FIGS. 1 and 2, thereby clarifying the object of the invention.

For example, a constant voltage power supply device consisting of a resistor 31, an energy diode 33, and a transistor 32 as shown in FIG. When inserted, this shunt device: 3 is composed of three terminals 371 H2S, 36, and the terminal 34 is for receiving power from the solar cell 2.
The terminal 35 is used for charging the storage battery 5 or supplying power to the load 6, and the remaining terminal 36d is used for branching 4. In the figure, 1 indicates sunlight that causes the solar cell 2 to generate electricity.

In the above configuration, the potential between the terminal 35 and the terminal 36 is clamped by the sum of the Zener voltage of the Zener diode 330 and the voltage between the base and emitter of the transistor 32 and is constant3. Therefore, the Zener voltage of the Zener diode 33 By selecting the value to be equal to the terminal voltage of the storage battery 5 at the time of completion of charging, that is, by setting the operating point of the shunt device 3 here, an excessive voltage is not applied between the terminals of the storage battery 5. When this happens, the shunt device 3 is activated to divert the current and prevent overcharging.

However, when a constant voltage power supply device is used as a constant voltage device in the above case, a voltage drop and a voltage loss occur due to the resistor 31 even while charging the storage battery 5, which causes a decrease in power conversion efficiency, and also when the constant voltage charging Since a branch current is passed through the transistor 32 while performing this, in order to ensure this, it is necessary to increase the area of the solar cell 20 or increase the number of parallel connections1.As a result, the cost of the solar cell is high9, and The overall size of the device is also on the verge of becoming larger.

The purpose of the present invention is to eliminate the above-mentioned disadvantages, reduce the area and number of solar cells used, and increase the conversion efficiency of waste power. In a solar battery power supply device that supplies power to a load while floatingly charging a storage battery with a solar type connection, a diode for reverse current is inserted between the Taiko battery and the storage battery, and a diode for when the storage battery is fully charged is inserted. p is achieved by connecting in parallel to the solar cell a two-terminal structure consisting of a power transistor connected between the collector and the base of a Zener diode having a Zener voltage corresponding to the voltage J+. .

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Fig. 3 is a circuit diagram showing an embodiment of the device of the present invention, and Fig. 4 is a circuit diagram of a shunt device used in the present invention. The terminal 34 and one terminal of the diode 4 are connected to the solar type M2.
Connect to one terminal of the Unfortunately, the other terminal 36 of the shunt device 3 is connected to the other terminal of the solar cell 2 and one of the storage battery 5.
one terminal of the load 6 and one terminal of the load 6. moreover,
The other terminal of the diode 4 is connected to the other terminal of the power storage/1i 25 and the other terminal of the load 6.

Therefore, a circuit is constructed by sequentially connecting a shunt device 3, a storage battery 5, and a load 6 in parallel to the solar cell 2, and inserting a diode 4 for backflow prevention between the shunt device 3 and the storage battery 5 in the forward direction. It is.

In addition, the Nyanto device @3 is composed of a Zener diode 33, a transistor 32, and a resistor 31 as in the conventional example, but as shown in FIG. It consists of connected series circuits, and a Zener diode 33 is inserted and connected between the collector terminal and base terminal of a transistor 32.

On the other hand, for the solar cell 2Kl′i, the voltage V
When P exceeds the peak point of the generated power P by +11g, there is a so-called drooping characteristic in which the electric current is attenuated3. Next, the operation will be explained4.It is assumed that the charging voltage of the large storage battery 5 has reached the terminal point. 1) At this time, set the Zener voltage of the Zener diode 3:3 to a value equal to or close to the terminal voltage of the storage battery 5, and set the terminal voltage of the solar cell 2 to the peak point 1 of the power P shown in FIG. E J-
Set so that it is equal to the Zener electric FE value.

In this way, even when the generated voltage of the solar cell 2 increases, the solar cell output current is activated and the solar cell output current is transferred to the circuit formed by the emitter 1 of the transistor 32, the resistor 31, and the solar cell 2. It works to reach a constant current range, lowering the terminal voltage of the solar cell 2.

As a result, the solar cell voltage becomes lower than the terminal voltage of the storage battery 5, the charging current to the storage battery 5 is cut off by the diode 4, and charging is stopped.

On the other hand, if the charging of the discharged storage battery 5 does not reach the end point 1, the shunt device 3 is not activated and the predetermined charging is continued. Therefore, since no current flows through the resistor 31 at this time, no power loss occurs.

As described above, in the solar battery power supply device of the present invention, the shunt device 3 is configured with two terminals and is configured not to operate while the storage battery is being charged, so that no power loss occurs.
This makes it possible to improve power conversion efficiency.

Furthermore, since there is no power loss, the number of solar cells used in series can be reduced, and overcharging of the storage battery can be reliably prevented with a small and low-cost device.

It can be used in a wide range of fields, including alarm power supplies for ultra-high voltage transformers using solar cells, power supplies for wireless lighthouses, and power supplies for municipal disaster prevention administrative radio systems.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of a conventional constant voltage power supply device, Fig. 2 is a circuit diagram of a solar battery power supply device using a constant voltage power supply device, and Fig. 3 is an embodiment of the solar battery power supply device of the present invention. The circuit diagram, FIG. 4, is a schematic diagram used in the present invention. 1...Solar light 2...Solar cell;...Nyanto device a1...j,'ll:
J'A: 32t・Langister; (3...Tsue)-
p-iode 34, . 35, 36...terminal 4
...Diode 5 ...Storage battery 6
...Load applicant Fuji Electric Manufacturing Co., Ltd.

Claims (1)

[Claims] In a solar battery power supply device that connects a solar battery and a storage battery in parallel and supplies power to the load while floating charging the storage battery, a backflow prevention diode is inserted between the solar battery and the storage battery, and a 1. A solar battery power supply device comprising: a two-terminal device having a two-terminal configuration consisting of a power transistor connected between a collector and a base and a Zener diode having a Zener voltage corresponding to a voltage in a fully charged state, and connected in parallel to a solar cell.