JPS6151881A - Solar-ray power generating system - Google Patents

Abstract

PURPOSE:To reduce the capacitance of a resistor by forming a specific solar-cell in constitution in which a contactor and the resistor are fitted only to a module. CONSTITUTION:When sunshine is insufficient and load 6 is not supplied with power, a contactor 2 is closed and currents only of a solar-cell module 1a are flowed through a resistor 3. When the value of the resistor 3 is sufficiently low, the currents are taken into a controller for a system apparatus 5 while using the terminal voltage of the resistor 3 as a control element because the currents are approximately proportional to the intensity of sunshine, and a pumping through which a system is started when the value exceeds some reference value can be prevented. A contactor 4 is left as it is opened on the suspension of the system, but it may be left as it is closed when the input impedance of the system apparatus 5 is sufficiently large. Accordingly, the same function as conventional devices can be displayed even when the contactor 2 and the resistor 3 are mounted to the solar-cell module 1a as one part of a solar-cell 1, thus, reducing currents flowing through the resistor 3.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a solar power generation system, and relates to a so-called pumping system in which solar energy is detected using a specific module of a group of solar cell modules, and the system repeatedly generates and stops generating power during periods of low sunlight. It was designed to prevent this.

[Prior art]

Figure 9E1 is a circuit diagram showing the configuration of a conventional system disclosed in, for example, Japanese Patent Laid-Open No. 59-76122. In the figure, (1) is a solar cell, and a plurality of solar cell modules (1a
). (2) is a contactor, and (3) is a resistor. As the resistor (3), a low value resistor is selected for the purpose of measuring solar energy. (4) is a contactor that is opened when the energy generated by the solar cell (1) is not taken into the system. (5) is system equipment, which shows the C converter, power storage device, control device, etc. in blocks. And solar cells (1)
The output of is supplied to the load (6) via the system equipment (5). If there is enough solar energy, contactor (
2) is opened and the contactor (4) is closed to send the generated energy to the system equipment (5). When there is not enough sunlight, such as in the morning or evening, or when the system is covered with thick clouds, the power generated by the solar cell (1) is so small that it cannot cover the power loss that is self-consumed by the system equipment (5).

Figure 2 shows a solar cell (with current on the vertical axis and voltage on the horizontal axis).
1) shows the power generation characteristics. In the figure, A is the power generation characteristic when there is sufficient sunlight. The system operates with two people at the point where it intersects with the load characteristic C, and the output voltage of the solar cell (11 is v people. B is the power generation characteristic when there is insufficient sunlight. The system operates at the point where it intersects with the load characteristic 0, PB. The output voltage of the solar cell (1) at this time will be VD.Va
becomes lower than the minimum voltage required by the system, and the system becomes stable (no longer able to operate and stops).

Then solar type/11! Since Fil is in a no-load state, it rises to Voa, which is an open circuit voltage. When the voltage becomes high, the system tries to extract power from the solar cell (11), but the voltage increases again and the system stops. This operation repeats, which is called a pumping state. This pumping is prevented. Therefore, in Figure 1, the solar cell (
A resistor (31) is connected to the output terminal of
Install the contactor + when the sunlight energy is insufficient.
21 is closed and the generated current of the solar 1u pond (1) is connected to the resistor (3).
), and this terminal voltage is taken into the control device of the system equipment (5). If the value of resistor (3) is low enough, this terminal voltage will be approximately proportional to the intensity of sunlight, so when the sunlight becomes strong enough, that is, the terminal voltage of this resistor (3) will exceed a certain value. Pumping can be prevented by opening the contactor (2) and starting the system when the system is turned on. However, as shown in Figure 1 (when the solar cell module (1a) has a 1 series configuration,
If the capacity as 1) is small, the current flowing through the resistor (31) is small and the resistor (3) is not very large, but by connecting many groups of solar cell modules (1a) in parallel, A,! In cases where the contactor (2) operates inconveniently, a resistor (31) is used. 3) could be burnt out.

[Summary of the invention]

The present invention was made for the purpose of improving such drawbacks,
A contactor and resistor are attached only to a specific solar cell module, and the same function as conventional devices can be achieved using a small-capacity metal resistor.

[Embodiments of the invention]

FIG. 3 is a circuit diagram showing one embodiment of the present invention.
The same symbols as in the figures indicate the same or equivalent parts.

If there is insufficient sunlight and power is not being supplied to the load (6), the contactor (2) is closed and the current of only the solar cell module (1a) flows through the resistor (3). If the value of resistor (3) is sufficiently low, this current is approximately proportional to the intensity of sunlight, so the terminal voltage of resistor (3) is taken into the control device of system equipment (5) as a control element, and this value is Pumping can be prevented by activating the system when a certain reference value is exceeded. The contactor (4) is opened when the system is stopped (but may remain closed if the input impedance of the system equipment (5) is sufficiently large. Even if a contactor (2) and a resistor (3) are attached to 1a), the same function as the conventional device can be achieved, so the current flowing through the resistor (3) becomes smaller, and the capacitance of the resistor (3) decreases. It is small and there is no risk of burnout.Furthermore, when there is sufficient sunlight, the solar cell module (1a) for measuring solar energy can be used as a solar cell for city departure by opening the contactor (2).

FIG. 4 shows another embodiment of the present invention, in which the solar cell module (1) for measuring irradiation energy shown in FIG.
a) is attached to the common bus (1b) side.

In this way, the common bus (1b) can be shared as a lead wire for taking in the terminal voltage of the resistor (3) to the control device, so the number of lead wires can be reduced by one.

In each of the above embodiments, a mechanical switch is used as the contactor (3), but a semiconductor switch such as a transistor can also be used since the required spout is small. In this case, maintenance-free and long life can be expected.

〔Effect of the invention〕

As described above, the present invention has a structure in which a contactor and a resistor are attached only to a specific solar cell module, and therefore has the effect of reducing the resistance of the resistor.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing the configuration of a conventional solar power generation system, Figure 2 is a diagram showing the power generation characteristics of a solar cell, and Figure 3 is a circuit diagram showing the configuration of a solar power generation system in an embodiment of the present invention. , FIG. 4 is a circuit diagram showing the configuration of a solar power generation system in another embodiment of the present invention. In the figure, (1) is a solar cell, (1a) is a solar cell module, (1b) is a common bus, (2) is a contactor,
(3) is a resistor, F4) is a contactor, (5) is a system device, and (6) is a load. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (4)

[Claims] (1) In a device that supplies power to a load using a solar cell configured by connecting a plurality of solar cell modules between a common bus, a resistor is connected between the terminals of a specific solar cell module via a contactor. , a solar power generation system characterized in that the terminal voltage of the resistor is used as a control element. (2) The solar power generation system according to claim 1, characterized in that when the load is released, the contacts are closed and the terminal voltage of the resistor is used as a control element as the output of the solar cell. (3) The solar power generation system according to claim 1 or 2, wherein the contact is a semiconductor switch such as a transistor. (4) The solar power generation system according to any one of claims 1 to 3, wherein a solar cell module connected to a common bus bar is used as the specific solar cell module.