JPH10308523A - Solar cell device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar cell device in which a light-receiving face can be cleaned quickly when a contamination is stuck to the light-receiving face. SOLUTION: Cooling water which is pumped up from a drain 16 by a pump 18 is supplied to a cooling-water tank 20, the cooling water flows to a cooling- water passage 14, and a solar cell element 10 is cooled. A control unit 26 monitors the temperature of the solar cell element 10, and it monitors whether a bypass circuit is operated or not. When the temperature of the solar cell element 10 is high, or when the bypass circuit of the solar cell element 10 is operated, the control unit 26 increases the discharge amount of the pump 18, and it increases the water level of the cooling-water tank 20. As a result, the cooling water flows from a discharge port 28 on a light-receiving face which is formed by covering the solar cell element 10 with a glass 12, the cooling capacity of the solar cell element 10 is increased, or a contamination such as a leaf or the like which is stuck to the solar cell element 10 is cleaned.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar cell device, and more particularly to an improvement in a solar cell device capable of cooling and cleaning a light receiving surface of the solar cell device.

[0002]

2. Description of the Related Art Since a solar cell device is usually used outdoors, leaves, dust and the like may accumulate on the light receiving surface of the solar cell device, which may lower the power generation efficiency of the solar cell device. Therefore, it is necessary to periodically clean the light receiving surface. JP-A-59-96
Japanese Patent Application Laid-Open No. 833 discloses a technique for cleaning the light receiving surface of such a solar cell device. In this conventional example, it is detected that the power generation amount of the solar cell device has dropped below the reference value, and at this time, water is caused to flow down to the light receiving surface of the solar cell device, or dirt on the light receiving surface is washed with a wiper device. , So as to recover the amount of power generated by the solar cell device.

[0003]

However, an ordinary solar cell device is composed of a plurality of solar cell elements. However, if the power generation amount of any of a small number of solar cell elements is reduced, the power generation of the solar cell apparatus is performed. There is a problem that it is difficult to detect a decrease in the amount. This is because, when the power generation of a specific solar cell element is reduced, a bypass circuit is provided to eliminate this effect. By the operation of the bypass circuit, it is excluded from the row of solar cell elements that are performing solar power generation. Thereby, even if the power generation amount of a small number of specific solar cell elements is reduced, the power generation amount of the entire solar cell device is not significantly reduced. Therefore,
This is because even if there is partial contamination due to leaves or the like on the light receiving surface of the solar cell device, it is difficult to reflect the decrease in power generation. For this reason, there is also a problem that it is difficult to accurately remove the deposits.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a solar cell device that can quickly clean a light receiving surface when dirt adheres to the light receiving surface.

[0005]

In order to achieve the above object, the present invention relates to a solar cell device comprising a plurality of solar cell elements, wherein a solar cell receives light according to the operation of a bypass circuit of the solar cell elements. It is characterized by comprising washing means for supplying a fluid to the surface.

[0006]

Embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings.

FIG. 1 shows a configuration of an embodiment of a solar cell device according to the present invention. In FIG. 1, the solar cell device has a plurality of solar cell elements 10, and the front side of the solar cell element 10 is covered with glass 12 to form a light receiving surface. A cooling water passage 14 for cooling the solar cell element 10 is provided on the back side of the solar cell element 10.
Is provided.

During normal operation, cooling water is pumped from a cooling water drain 16 by a pump 18 and supplied to a cooling water tank 20. The entire amount of the cooling water supplied to the cooling water tank 20 passes through the cooling water passage 14, and falls on the cooling water tray 22 while cooling the solar cell element 10.
The cooling water that has fallen into the cooling water tray 22 is cooled by the radiator 24 and collected again by the drain 16. As described above, during normal operation, the cooling water is circulated in the above-described cycle, and the solar cell element 10 is cooled. In this case, the operation of the pump 18 is controlled by the control unit 26.

On the other hand, when the temperature of the solar cell element 10 becomes higher than a specified value during operation, or when a bypass diode of a specific solar cell element 10 is activated, the control unit 26 detects this and the pump 18 Is controlled so as to increase the discharge amount. Accordingly, the discharge amount from the pump 18 increases, and the amount of cooling water supplied to the cooling water tank 20 increases. Therefore, the cooling water is supplied to the cooling water passage 1
4 alone will not be able to flow, and part will be discharged from the discharge port 28 provided in the cooling water tank 20. This allows
Cooling water can be supplied to the light receiving surface of the solar cell device, and the light receiving surface can be cleaned. Note that the cooling water discharged from the discharge port 28 flows on the light receiving surface, and the cooling water tray 22
In this case, and is collected in the drain 16 via the radiator 24 in this case as well.

FIG. 2 shows a state of connection of n solar cell elements constituting the solar cell device. In FIG.
Usually, the voltage generated by each solar cell element 10 is V
₀ , n of which are connected in series to generate a total voltage of nV ₀ . This voltage nV ₀ is consumed by the load 32. At this time, when a failure occurs in any of the solar cell elements 10 or when a leaf or the like adheres to a specific solar cell element 10, the power generation capability of the solar cell element 10 is significantly reduced. For this reason, no current flows through the solar cell element 10, and the amount of power generation as a whole is greatly reduced. To prevent this,
With respect to the solar cell element 10 in which the above-described trouble has occurred, the solar cell element 10
Is bypassed, and the influence of the solar cell element 10 in which a trouble has occurred is removed. Therefore, FIG.
The control unit 26 shown in FIG. 2 constantly monitors the operation of the bypass circuit 30. When the bypass circuit 30 operates, the control unit 26 increases the discharge amount of the pump 18 as described above. Has been implemented.

When the temperature of the solar cell element 10 rises, it is considered that only the cooling water passage 14 shown in FIG. 1 has insufficient cooling capacity. Therefore, the control unit 26 constantly monitors the temperature of the solar cell element 10 and, even when the temperature becomes higher than the reference value, performs control so as to increase the discharge amount of the pump 18 as described above.

FIG. 3 shows a flowchart of the control operation of the pump 18 of the solar cell device shown in FIG. 3, the control unit 26 constantly monitors the temperature Ts of the solar cell element 10, the temperature Ts is determined whether higher than a predetermined reference temperature T ₀ (S1). The control unit 26 also monitors whether the bypass circuit 30 of the solar cell element 10 is operating (S2).

In the above S1, S2, if the temperature Ts is and the bypass circuit 30 lower than the reference temperature T ₀ is not operating, the pump 18 is a normal operation, flows the discharge amount in the cooling water passage 14 (S
3).

[0014] On the other hand, in S1, S2, is higher or the bypass circuit 30 than the temperature Ts is the reference temperature T ₀ of the solar cell element 10 is in operation, the control unit 26 to the high power operation of the pump 18 Switch (S4). Thereby, the discharge amount of the pump 18 increases,
The cooling water cannot flow through the cooling water passage 14 alone, and is discharged from the discharge port 28 of the cooling water tank 20.

According to the above steps, when the cooling capacity in the cooling water passage 14 is insufficient, or when dirt such as leaves adhere to the light receiving surface and the power generation capacity of the specific solar cell element 10 is reduced, the discharge is performed. By flowing the cooling water from the outlet 28 to the light receiving surface, it is possible to recover the cooling capacity and to clean dust and the like. Further, according to the present embodiment, the discharge amount of the pump 18 is switched when necessary, so that the pump 1
8, the power consumption of the solar cell element 10 can be effectively used.

As a method for detecting whether or not the bypass circuit 30 has operated, for example, a method in which an ammeter is inserted in series with the bypass circuit 30 and the control unit 26 detects the operation of the bypass circuit 30 based on this value is considered. Can be Alternatively, for example, a method may be used in which a photocoupler is connected to the bypass circuit 30 to detect the operation of the bypass circuit 30. Further, the voltage between both ends of the bypass diode constituting the bypass circuit 30 may be monitored. In addition, as a method of confirming which solar cell element 10 has an abnormality, the solar cell elements 10 are divided into groups, and the two groups are compared with each other by the above-described current value or voltage value. It is also possible to take a method of narrowing down the generated solar cell elements 10.

As described above, it is possible to specify which solar cell element 10 has a trouble. For this reason, it is also possible to clean only the portion of the solar cell element 10 where a trouble has occurred. FIG. 4 shows a configuration example in this case. In FIG.
, A solenoid valve 34 is attached. This solenoid valve 3
The opening and closing of 4 is controlled by the control unit 26. As described above, the control unit 26 can determine which of the solar cell elements 10 has a trouble such as the attachment of leaves by operating the bypass circuit 30 (FIG. 2). For this reason, if only the electromagnetic valve 34 corresponding to the solar cell element 10 in which a trouble has occurred is opened, the light receiving surface can be cleaned only in that portion.
Thus, the discharge amount of the pump 18 can be further reduced, and the power consumption of the pump 18 can be reduced.

FIG. 5 shows a configuration diagram of another embodiment of the solar cell device according to the present invention. In FIG. 5, the cooling water in the drain 16 is supplied to the pump 1 through the radiator 24.
1 is different from FIG. 1 in that it is pumped up by the cooling water 8 and flows upward from the bottom in the cooling water passage 14. Cooling water passage 1
The cooling water flowing in 4 enters the cooling water tank 20,
It returns to the drain 16 again via the valve 36.

Also in this embodiment, the control unit 26 controls the temperature of the solar cell element 10 and the bypass circuit 3
0 is monitored for activation. When the control unit 26 detects such a trouble of the solar cell element 10, the valve 36 is closed. When the valve 36 is closed by the control unit 26, the cooling water circulated by the pump 18 cannot return from the valve 36 to the drain 16. Therefore, the cooling water tank 2
The water level in 0 rises, and the cooling water flows from the discharge port 28 to the light receiving surface as in FIG. The cooling water flowing on the light receiving surface is dropped to the cooling water tray 22 and returns to the drain 16 from the cooling water tray 22.

FIG. 6 shows a flow of the opening / closing control of the valve 36 of the embodiment shown in FIG. In FIG.
Control unit 26 monitors whether a higher or not than the temperature monitors, the reference temperature T ₀ the temperature Ts of the solar cell elements 10 (S11). Further, the control unit 26 also monitors whether or not the bypass circuit 30 is operating (S12).

In steps S11 and S12, the solar cell element 1
When the temperature Ts of ₀ is lower than the reference temperature T0 and the bypass circuit 30 is not operating, the valve 36 is opened as a normal operation.

[0022] On the other hand, S11, in S12, if the higher or the bypass circuit 30 than the temperature Ts is the reference temperature T ₀ of the solar cell element 10 is in operation, the valve 3
6 is closed (S13).

With the above operation, the solar cell element 1
If a trouble occurs at 0 or the cooling capacity is insufficient only with the cooling water passage 14, the valve 36 is closed and the cooling water is discharged from the discharge port 28.

In the present embodiment, the discharge amount of the pump 18 is fixed. Therefore, control for switching the discharge amount of the pump 18 becomes unnecessary, and the cost of the pump 18 can be reduced.

FIG. 7 shows still another embodiment of the solar cell device according to the present invention. In FIG. 7, the pump 18
The configuration in which the cooling water pumped by the cooling water cools the solar cell element 10 while passing through the cooling water passage 14 and returns to the drain 16 again is the same as the embodiment shown in FIG. In the present embodiment, a pump 38 is provided as a cooling water circulation pump in addition to the pump 18. The cooling water discharged by the pump 38 is supplied to the cooling water tank 20 from the cooling water pipe 42 or 44 via the switching valve 40. The cooling water supplied to the cooling water tank 20 is discharged from the discharge port 28 to the light receiving surface of the solar cell device, and the cooling water
Is collected in the drain 16 via the radiator 46.

In the cooling water tank 20, there is provided a deer playing part 48 as shown in FIG. The deer mascot 48 has a container 50 for receiving cooling water at one end, and a rod 54 having a weight 52 attached to the other end, which is attached to a support bar 56 at a fulcrum 58. This 5
4 is attached so as to be rotatable about a fulcrum 58. When the cooling water is supplied from the cooling water pipe 44 to the container 50 of the deer masquerade section 48, the container 50 is kept lifted by the weight 52 up to a certain amount. Becomes heavier than the weight 52, and the container 50 tilts downward as shown by the broken line in FIG. As a result, the cooling water supplied into the container 50 spills into the cooling water container 20 at a stretch, and the cooling water flows from the discharge port 28 of the cooling water container 20 to the light receiving surface at a stretch. As described above, by flowing the cooling water to the light receiving surface at a stretch, the effect of cleaning dusts such as leaves attached to the light receiving surface can be enhanced. The switching of the switching valve 40 is performed by the control unit 26 (not shown) shown in FIGS. Also,
The start / stop of the pump 38 is also controlled by the control unit 26.

FIG. 7 also shows a plan view of a light receiving portion constituted by the solar cell element 10 and a side view as viewed from the direction of arrow A. As shown in this side view, walls 60 are formed on both ends of the light receiving section. By forming the walls 60 at both ends as described above, it is possible to prevent the cooling water flowing on the light receiving surface from scattering.

FIG. 9 shows a flow of the operation of the embodiment shown in FIG. In FIG. 9, first, the value of the counter k is set to 0 (S21). The counter k indicates the number of times of the cleaning operation in which the cooling water is applied to the light-receiving surface at once by using the above-described deer masquerade section 48.

Next, the operation of the pump 18 (pump P1) for flowing the cooling water through the cooling water passage 14 is started (S2).
2).

The control unit 26 not shown in FIG. 7 monitors whether a higher or not than the reference temperature T ₀ temperature Ts of the solar cell elements 10 (S23). In S23, when the temperature Ts of the solar cell element 10 is higher than the reference temperature T _0, it means that missing in cooling capacity of the cooling water passage 14, the pump 38 (pump P
The operation of 2) is started (S24). Further, the switching valve 40 is switched by the control unit 26,
The cooling water pipe 42 is used (S25). This allows
The cooling water from the pump 38 is supplied to the cooling water tank 2 at a constant flow rate.
0, and flows from the discharge port 28 to the light receiving surface at a constant flow rate. For this reason, the shortage of the cooling capacity by the cooling water passage 14 can be compensated.

On the other hand, in S23, the solar cell element 10
Of if the temperature Ts is lower than the reference temperature T ₀ is, the pump 38 is stopped (S26), the counter k is is confirmed whether greater than a predetermined value k ₀ (S27).

At S27, the counter k is set to a predetermined value k ₀
If smaller, it is confirmed whether or not the bypass circuit 30 is operating (S28). In S28, when the bypass circuit is not operating, the normal operation is performed,
Solar power generation is performed while cooling the solar cell element 10 with cooling water by the pump 18.

If the bypass circuit is operating in S28, the pump 38 is started (S29),
The switching valve 40 is switched to the cooling water pipe 44 side to supply the cooling water to the container 50 of the deer monster unit 48. Deer Odds Club 4
According to 8, as described above, the cooling water is flushed to the light receiving surface at once, and the light receiving surface is washed once (S30), and then the pump 38 is stopped (S31).

Next, the counter k is incremented by 1 (S32), and the steps from S23 are repeated. At this time, if the counter k has become larger than the predetermined value k ₀ in S27, it means that dust on the light receiving surface is not removed even if the cleaning is performed by the deer adobe unit 48 a predetermined number of times. A cell abnormality is displayed on the control panel (S33). Thereby, the administrator is notified of the abnormality of the solar cell device. After waiting for T time in this state (S34), the steps from S23 are repeated again.

Through the above steps, dust such as leaves of a tree attached to the light receiving surface can be efficiently removed. If the cooling capacity is insufficient, cooling water can be flowed over the light receiving surface at a constant flow rate. Further, by displaying an abnormality display on the control panel, it is possible to prompt the administrator to perform early repair.

In each of the embodiments described above, it is also possible to spray the cooling water by connecting the cooling water from the pump 18 or the pump 38 to the discharge port 28 as a spray. As a result, the efficiency of foreign matter removal can be further improved.

[0037]

As described above, according to the present invention,
When dust such as leaves of a small number of trees adheres to the light receiving surface of the solar battery device, the sunlight is interrupted, the power generation amount of the solar battery element is reduced, and it is detected that the bypass circuit has been activated. Thereby, a fluid such as water is supplied to the light receiving surface,
Garbage can be efficiently removed. As a result, it is possible to quickly recover the power generation amount of the solar cell element.

It is also possible to confirm which bypass circuit has been activated, and to selectively flow the fluid only in the portion of the solar cell element where the bypass circuit has been activated.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of a solar cell device according to the present invention.

FIG. 2 is a circuit diagram showing a connection method of a solar cell element and a bypass circuit.

FIG. 3 is a flowchart of operation control of the pump of the embodiment shown in FIG. 1;

FIG. 4 is a diagram showing a modified example when cooling water is caused to flow on a light receiving surface.

FIG. 5 is a configuration diagram of another embodiment of the solar cell device according to the present invention.

FIG. 6 is a flowchart of valve opening / closing control of the embodiment shown in FIG. 5;

FIG. 7 is a configuration diagram of still another embodiment of the solar cell device according to the present invention.

FIG. 8 is a diagram showing a structure of a deer mascot in the embodiment of FIG. 7;

FIG. 9 is a flowchart of the operation of the embodiment shown in FIG. 7;

[Explanation of symbols]

Reference Signs List 10 solar cell element, 12 glass, 14 cooling water passage, 16 drain, 18 pump, 20 cooling water tank, 22 cooling water tray, 24 radiator, 26 control unit, 28 outlet, 30 bypass circuit, 32 load, 34 solenoid valve , 36 valves, 38
Pump, 40 switching valve, 42, 44 cooling water piping, 4
6 radiators, 48 deer mascots, 50 containers, 52
Weight, 54, 56 support rod, 58 fulcrum, 6
0 wall.

Claims (1)

[Claims] 1. A solar cell device comprising a plurality of solar cell elements, comprising a washing unit for supplying a fluid to a light receiving surface of a solar cell according to an operation of a bypass circuit of the solar cell element. Solar cell device.