Solar panel anomaly detection device

Abstract

The objective is to provide a solar panel anomaly detection device that can identify the factors causing a decrease in the power generation efficiency of solar panels. [Solution] The power generation prediction unit 20 predicts the power generation amount (West) of the solar cell panel, the power generation calculation unit 22 obtains the solar cell generation voltage and solar cell generation current detected by the power generation detection device and calculates the actual power generation amount of the solar cell panel at the time of prediction, and the deviation calculation unit 24 calculates the difference between the predicted power generation amount and the actual power generation amount of the solar cell panel 14, as well as the difference twice. The determination unit 26 then determines that the solar cell panel is deteriorating if the deviation is greater than or equal to a predetermined first threshold and continues for a predetermined first hour or longer, and determines that an obstruction is attached to the solar cell panel if the condition of the deviation being greater than the first threshold exceeds a second threshold and continues for a second hour which is shorter than the first hour.

Description

Technical Field

[0001] The present invention relates to an abnormality determination device for a solar cell panel.

Background Art

[0002] Patent Document 1 discloses an abnormality determination device for a solar system in which a first solar cell module and a second solar cell module are connected in series, the first acquisition unit for acquiring the first power generation state showing the relationship between the power generation voltage of the entire first and second solar cell modules and the power generation voltage of the second solar cell module alone during vehicle parking, the second acquisition unit for acquiring the second power generation state showing the relationship between the power generation voltage of the entire first and second solar cell modules and the power generation voltage of the second solar cell module alone during vehicle travel, and a determination unit for determining whether or not an abnormality that reduces the power generation power has occurred in the solar cell module based on the change between the first power generation state and the second power generation state.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the technology of Patent Document 1, it is possible to easily determine whether or not an abnormality that reduces the power generation power of the solar cell module has occurred without using information regarding changes in solar radiation. However, as factors for reducing the power generation efficiency, various factors such as aging deterioration and adhesion of shielding materials to the panel are conceivable, and there is room for improvement in order to grasp the factors for reducing the power generation efficiency.

[0005] This invention has been made in consideration of the above facts, and aims to provide a solar panel anomaly detection device that can identify the factors causing a decrease in the power generation efficiency of a solar panel. [Means for solving the problem]

[0006] The solar panel abnormality detection device according to the first embodiment includes: a power generation prediction unit that predicts the amount of power generated by the solar panel; a power generation calculation unit that calculates the actual amount of power generated by the solar panel at the time of the prediction; and a determination unit that determines that the solar panel is deteriorating if the discrepancy between the prediction result of the power generation prediction unit and the calculation result of the power generation calculation unit is greater than or equal to a predetermined first threshold and continues for a predetermined first hour or longer, and determines that an obstruction has adhered to the solar panel if the discrepancy exceeds a second threshold greater than the first threshold and continues for a second hour shorter than the first hour.

[0007] According to the first embodiment, the power generation prediction unit predicts the amount of power generated by the solar panel, and the power generation calculation unit calculates the actual amount of power generated by the solar panel at the time of prediction.

[0008] The determination unit determines that the solar panel has deteriorated if the discrepancy between the prediction result of the power generation prediction unit and the calculation result of the power generation calculation unit exceeds a predetermined first threshold and continues for a predetermined first hour or longer. If the discrepancy exceeds a second threshold (which is greater than the first threshold) and continues for a second hour (shorter than the first hour), it determines that an obstruction has adhered to the solar panel. This makes it possible to identify the factors causing a decrease in the power generation efficiency of the solar panel. [Effects of the Invention]

[0009] As described above, the present invention provides a solar panel abnormality detection device that can identify the factors causing a decrease in the power generation efficiency of a solar panel. [Brief explanation of the drawing]

[0010] [Figure 1]This figure shows the schematic configuration of the solar system according to this embodiment. [Figure 2] This is a block diagram showing the functional configuration of the abnormality detection ECU. [Figure 3] This figure shows the change in power output from solar panels and the change in the deviation rate from the prediction. [Figure 4] This flowchart shows an example of the processing flow performed in the abnormality detection ECU of the solar system according to this embodiment. [Modes for carrying out the invention]

[0011] Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. Figure 1 is a diagram showing the schematic configuration of a solar system according to this embodiment.

[0012] The solar system 10 according to this embodiment includes an abnormality detection ECU (Electronic Control Unit) 12 as an example of an abnormality detection device, a solar cell panel 14, and a power generation amount detection device 16. In this embodiment, the solar system 10 is described as being mounted on a vehicle as an example, but it is not limited to this and may not be mounted on a vehicle.

[0013] The solar cell panel 14 generates electricity when exposed to sunlight. In this embodiment, an example is shown that includes a single solar cell panel 14, but multiple solar cell panels 14 may be included.

[0014] The power generation detection device 16 is connected to the solar panel 14 and is provided to detect the total amount of power generated by the solar panel 14. The power generation detection device 16 detects the voltage generated by the solar panel and the current generated by the solar panel.

[0015] The abnormality detection ECU 12 determines abnormalities in the solar panel 14 based on the total power generated by the solar panel 14 detected by the power generation detection device 16. In this embodiment, the abnormality detection ECU 12 determines abnormalities such as deterioration of the solar panel 14 or the attachment of obstructing materials (e.g., bird droppings, garbage, sand, dirt, etc.).

[0016] The abnormality detection ECU 12 consists of a general-purpose microcomputer including a CPU (Central Processing Unit) 12A, ROM (Read Only Memory) 12B, RAM (Random Access Memory) 12C, storage 12D, interface (I / F) 12E, and bus 12F.

[0017] The CPU 12A is a central processing unit that controls the overall operation of the device by executing various programs. The ROM 12B stores various control programs and parameters, such as an abnormality detection program that determines abnormalities in the solar panel 14. The RAM 12C is used as a work area when the CPU 12A executes various programs. The storage 12D is composed of various storage units such as an HDD (Hard Disk Drive), SSD (Solid State Drive), and flash memory, and stores various data and application programs. The I / F 12E is connected to a power generation amount detection device 16, and the detection results of the power generation amount detection device 16 can be input to the abnormality detection ECU 12.

[0018] The various parts of the abnormality detection ECU 12 described above are electrically interconnected by the bus 12F. In this embodiment, the abnormality detection program is described as being stored in the ROM 12B, but it may also be stored in the storage 12D.

[0019] Next, we will explain the functions of the abnormality detection ECU12. Figure 2 is a block diagram showing the functional configuration of the abnormality detection ECU12.

[0020] The abnormality determination ECU 12 functions as a power generation amount prediction unit 20, a power generation amount calculation unit 22, a deviation calculation unit 24, and a determination unit 26 by the CPU 12A executing an abnormality determination program stored in the ROM 12B.

[0021] The power generation amount prediction unit 20 predicts the power generation amount (West) of the solar cell panel 14. For example, since the power generation amount of the solar cell panel 14 changes according to the vehicle position, date and time, solar irradiance amount, etc., the power generation amount of the solar cell panel 14 is predicted using at least one of the vehicle position, date and time, and solar irradiance amount. The vehicle position and date and time are acquired from the GPS, for example, by providing a GPS (Global Positioning System). Also, the solar irradiance amount may be predicted from weather forecast information, for example, or the detection result of a solar radiation sensor may be acquired. Using these, the power generation amount of the solar cell panel 14 is predicted.

[0022] The power generation amount calculation unit 22 acquires the solar cell generated voltage and the solar cell generated current detected by the power generation amount detection device 16 and calculates the actual power generation amount at the time of prediction of the solar cell panel 14. The calculation of the power generation amount is calculated by the following formula. Wobs(t)=Vp(t)×Ip(t) (Vp: solar cell generated voltage, Ip: solar cell generated current)

[0023] The deviation calculation unit 24 calculates the deviation between the predicted power generation amount and the actual power generation amount of the solar cell panel 14 based on the prediction result of the power generation amount prediction unit 20 and the calculation result of the power generation amount calculation unit 22. For example, the difference (Wdiff) and the second difference (Wdiff2) between the predicted power generation amount and the actual power generation amount are calculated as the deviation between the predicted power generation amount and the actual power generation amount. Wdiff(t)=West(t)-Wobs(t) Wdiff2(t)=Wdiff(t)-Wdiff(t - 1)

[0024] The determination unit 26 determines the abnormality of the solar cell panel 14 based on the calculation result of the deviation calculation unit 24.

[0025] Specifically, in outer space, since there is no influence from weather, as shown in Figure 3, the amount of power generated by the solar panel 12 changes according to the movement of the sun, and if the rate of discrepancy between the predicted amount of power generated and the actual amount of power generated gradually decreases, it can be determined that the solar panel 14 is deteriorating. On the other hand, if the tilt changes midway through, or if the deterioration is greater than the expected reduction, it can be determined that there is an obstruction. On Earth, the above determination is made by adding the weather element to the above determination. In the case of clear skies, the same determination as in outer space is made. The predicted amount of power generated is variable according to the weather. However, even on cloudy days, the degree of cloud cover and even on sunny days, temporary cloud formation can cause fluctuations. Therefore, the above determination is made when a similar rate of discrepancy continues for a certain period of time or longer.

[0026] Therefore, the determination unit 26 determines whether the solar cell panel 14 is deteriorating or has an obstruction attached, based on the deviation calculated by the deviation calculation unit 24 and the duration of the deviation. In this embodiment, if the deviation calculated by the deviation calculation unit 24 is greater than or equal to a predetermined first threshold and continues for a predetermined first hour or longer, it is determined that the solar cell panel 14 is deteriorating. On the other hand, if the condition in which the deviation exceeds a second threshold, which is greater than the first threshold, continues for a second hour that is shorter than the first hour, it is determined that an obstruction has attached to the solar cell panel 14. For example, if the condition Wdiff2(t)>Δ(predetermined second threshold) continues for a predetermined period of time, it is determined that an obstruction has attached.

[0027] Next, we will describe the specific processing performed by the abnormality detection ECU 12 of the solar system 10 configured as described above. Figure 4 is a flowchart showing an example of the processing flow performed by the abnormality detection ECU 12 of the solar system 10 according to this embodiment. Note that the processing in Figure 4 is started, for example, at predetermined intervals.

[0028] In step 100, the CPU 12A predicts the amount of power generated by the solar panel 14 and proceeds to step 102. That is, the power generation prediction unit 20 predicts the amount of power generated by the solar panel 14.

[0029] In step 102, the CPU 12A calculates the amount of power generated by the solar panel 14 and proceeds to step 104. Specifically, the power generation calculation unit 22 acquires the solar cell generation voltage and solar cell generation current detected by the power generation detection device 16, and calculates the actual amount of power generated by the solar panel 14 during the prediction period using the formula Wobs(t) = Vp(t) × Ip(t).

[0030] In step 104, the CPU 12A calculates the difference in power generation and proceeds to step 106. Specifically, the deviation calculation unit 24 calculates the difference between the predicted power generation and the actual power generation using the formula Wdiff(t) = West(t) - Wobs(t).

[0031] In step 106, the CPU 12A calculates the difference twice as the deviation and proceeds to step 108. That is, the deviation calculation unit 24 calculates the difference twice using the formula Wdiff2(t) = Wdiff(t) - Wdiff(t-1).

[0032] In step 108, the CPU 12A determines whether the calculated deviation (difference over two steps) is greater than or equal to the first threshold and continues for more than one hour. The determination unit 26 makes this determination, and if the determination is affirmative, the process proceeds to step 110; otherwise, the process proceeds to step 112.

[0033] In step 110, the CPU 12A terminates the series of processes as a degradation determination. That is, the determination unit 26 determines that the solar cell panel 14 has deteriorated.

[0034] On the other hand, in step 112, it is determined whether the calculated deviation (difference over two steps) has remained above a predetermined second threshold for a predetermined second time. The determination unit 26 makes this determination, and if the determination is affirmative, the process proceeds to step 114; if negative, the series of processes ends.

[0035] In step 114, the CPU 12A determines that an obstruction has been found and terminates the series of processes. That is, the determination unit 26 determines that an obstruction has been found on the solar panel 14. If an obstruction has been found, a warning may be issued to remove the obstruction.

[0036] By performing this processing, the solar system 10 according to this embodiment can determine the deterioration of the solar cell panel 14 and the adhesion of shading substances, making it possible to estimate the factors causing the decrease in power generation efficiency. Furthermore, if it is determined that the cause is the adhesion of shading substances, it becomes possible to quickly remove the adhesion and improve power generation efficiency.

[0037] Furthermore, the solar system 10 according to this embodiment can detect abnormalities in the solar panels 12 even when the vehicle is not moving. However, on Earth, there may be buildings or other structures around the vehicle that block the sun for a certain period of time. In this case, by performing the check over a period of one day or more, it becomes possible to perform the check without being affected by the surroundings. On the other hand, in environments where there is nothing to block the sun, such as outer space, it is possible to perform the check in a short period of time.

[0038] In the above embodiment, an example of calculating the deviation by calculating the difference twice was described, but this is not the only method, and the deviation may be calculated using other methods.

[0039] Furthermore, although the processing performed by the abnormality detection ECU12 in each of the above embodiments has been described as software processing performed by executing a program, it is not limited to this. For example, it may be processing performed by hardware such as a GPU (Graphics Processing Unit), ASIC (Application Specific Integrated Circuit), and FPGA (Field-Programmable Gate Array). Alternatively, it may be processing that combines both software and hardware. In the case of software processing, the program may be stored on various storage media and distributed.

[0040] Furthermore, the present invention is not limited to the above, and it is of course possible to implement it in various modified forms without departing from its spirit. [Explanation of symbols]

[0041] 10 Solar Systems 12 Abnormality judgment ECU (abnormality judgment device) 14 Solar panels 16 Power generation amount detection device 20 Power generation forecasting section 22 Power generation calculation unit 24. Discrepancy Calculation Unit 26 Judgment section

Claims

[Claim 1] A power generation prediction unit that predicts the amount of power generated by a solar panel, A power generation calculation unit that calculates the actual power generation amount of the solar cell panel at the time of the prediction, A determination unit determines that if the discrepancy between the prediction result of the power generation prediction unit and the calculation result of the power generation calculation unit exceeds a predetermined first threshold and continues for a predetermined first hour or longer, the solar cell panel is degraded. If the discrepancy exceeds a second threshold, which is greater than the first threshold, for a second hour shorter than the first hour, the determination unit determines that an obstruction has adhered to the solar cell panel. A solar panel anomaly detection device, including one for solar panels.

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