JPH07123594A - Abnormality detector for solar cell - Google Patents

Abstract

PURPOSE:To allow positive detection of abnormality in a solar cell by comparing a newly measured generated power amount data with a generated power amount data measured under corresponding state and stored in a memory means thereby deciding whether the solar cell is abnormal or not. CONSTITUTION:A measured generated power amount data of a solar cell 8 and a measuring condition data, e.g. weather, are stored sequentially in a memory 19. A decision section 22 decides whether the solar cell 8 is abnormal by comparing the measured generated power amount data with a generated power amount data measured under corresponding conditions and stored in the memory 19. In other words, the decision is made by comparing the amounts measured under similar weather conditions. This constitution allows positive detection of abnormality in the solar cell 8 with no influence of variation in the ambient conditions, e.g. variation in the quantity of solar radiation due to the weather.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar cell abnormality detecting device for detecting abnormality such as deterioration, failure or adhesion of a substance on the surface of a solar cell used for photovoltaic power generation.

[0002]

2. Description of the Related Art In recent years, a system has been developed in which a distributed power source by solar power generation and a commercial power source are interconnected, and when the distributed power source cannot supply the power, the system side supplies the power. Has been done.

[0003]

The amount of power generated by a solar cell used in such a system is unstable because it greatly depends on the surrounding conditions such as changes in the amount of solar radiation due to the weather and temperature changes. .

For this reason, even if an abnormality such as aging deterioration of the solar cell, failure, or adhesion of an object (falling leaves or bird droppings) to the surface of the solar cell arranged outdoors, the amount of power generation is reduced. It is difficult to determine whether the cause is the mere unevenness of the amount of power generation based on the characteristics of the solar cell due to the above-mentioned change in the surrounding conditions or the abnormality that has occurred in the solar cell.

The present invention has been made in view of the above points, and an object of the present invention is to make it possible to reliably detect an abnormality occurring in a solar cell.

[0006]

In order to achieve the above-mentioned object, the present invention is constructed as follows.

That is, in the abnormality detecting device for a solar cell according to the present invention, the power generation amount data of the solar cell which is sequentially measured in a unit of a fixed period is sequentially stored together with the situation data indicating the state of the measured fixed period. Storage means, the power generation amount data of the solar cell measured for a certain period of time, and the power generation amount data measured in a situation corresponding to the situation in which this power generation amount data is measured and already stored in the storage means, And a determination unit that determines whether or not there is an abnormality in the solar cell by comparison.

[0008]

According to the above configuration, the measured power generation amount data and the measured condition, for example, the condition data indicating the weather and the like are sequentially stored in the storage means, and the measured power generation amount data and the power generation amount data are stored. Since the presence or absence of abnormality is determined by comparing with the power generation amount data that has been measured in a situation corresponding to the measured condition and already stored in the storage means, for example, the power generation amount measured when the weather is similar. It will be judged by comparing the data, therefore it will be possible to detect the change in the power generation data due to the abnormality of the solar cell without being affected by the change in the surrounding conditions such as the change in the amount of solar radiation due to the weather. .

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a system including a solar cell abnormality detecting device according to an embodiment of the present invention. In this embodiment, a distributed power source by solar power generation and a commercial power source are system-interconnected. It will be explained by applying it to the system.

In FIG. 1, reference numeral 1 denotes a power system of a commercial power source, which is provided in a main power source 2 of a power station, a substation 3 for stepping down the power from the power station 2 and distributing the power, and a distribution line 4. The circuit breaker 5 and the pole transformer 6 for stepping down the supplied power and supplying it to each home are provided.

Reference numeral 7 denotes a distributed power source installed in each home. The distributed power source 7 includes a solar cell 8 and an inverter 9 for converting DC power output from the solar cell 8 into AC power. I have it. Reference numeral 10 is a protection device that disconnects the distributed power supply 7 from the power system 1 of the commercial power supply when some accident occurs, and 13 is a domestic load.

In such a system, when DC power is output from the solar cell 8, it is converted into AC power of a predetermined frequency by the inverter 9 and the AC power is supplied to the domestic load 13, which can be covered by this AC power. The non-existing power is supplied from the power grid 1 of the commercial power supply.

Reference numeral 14 denotes a solar cell abnormality detecting device according to the present invention. The abnormality detecting device 14 measures the amount of power generation of the solar cell 8 to determine whether there is an abnormality, and when it determines that there is an abnormality, A message to that effect is displayed.

The abnormality detecting device 14 of this embodiment measures the power generation amount of the solar cell 8 every day and shows the power generation pattern and the peak power generation amount showing the change of the power generation amount, such as the weather, temperature or sunshine duration of the day. When the power generation pattern and peak power generation amount for a day are newly stored together with the status data indicating the status, the power generation pattern and peak power generation amount that have been measured and stored in a situation similar to the condition of the day are already stored. Is read out and compared, and when the power generation pattern and the peak power generation amount are clearly reduced, it is judged to be abnormal and displayed.

FIG. 2 is a block diagram of the solar cell abnormality detecting device 14.

In the figure, reference numeral 15 is a power generation amount measuring section for measuring the power generation amount of the solar cell 8, 16 is a weather condition sensor such as a temperature sensor or a sunshine sensor, 17 is a counter for counting the date, and 18 is an output of these. A data creating section for creating data to be stored based on 19 is a memory as a storage means for storing the data created by the data creating section 18, 2
0 is a memory control unit that controls writing or reading of data to or from the memory 19 on a daily basis based on the output from the counter 17, and 21 is a unit of reading data of the day in which measured conditions are similar. The similar data reading unit, 22 is a judging unit for comparing the latest day's data with the previous day's data measured in a similar situation to judge whether or not there is an abnormality in the solar cell 8, and 23 is an abnormality. When it is determined that it is, it is a display unit that displays that effect.

The data creating section 18 stores in advance what kind of power generation pattern the solar cell 8 will have in accordance with the weather when the solar cell 8 is normal. That is, the solar cell 8
The amount of power generation in one day changes depending on the weather, for example, as shown in FIG. 3 (A) in fine weather and as shown in FIG. 3 (B) in cloudy weather. As described above, in the solar cell 8, since the power generation pattern differs depending on the weather, the data creation unit 18 stores the power generation patterns according to the plurality of types of weather stored in advance and the power generation pattern measured every day. The weather of the measurement day is determined by comparing

In the data creating section 18, the data of the measured power generation pattern, peak power generation amount, temperature and sunshine duration from the weather condition sensor 16 and date (year / month / day) of the measurement date from the counter 17 are obtained as described above. Memory 1 together with the weather data indicating the weather of the measurement day determined in this way
Created as data to be stored in 9.

The memory control unit 20 stores the data created by the data creating unit 18, that is, the data including the power generation pattern, the peak power generation amount, the temperature, the sunshine duration, the date, and the weather, in the memory 19 every day. Also, the latest data of the day is read and given to the determination unit 22.

The similar data reading section 21 reads the similar day data already stored in the memory 19 when the weather, temperature and sunshine time are measured on a similar day on the latest day, and the similar data reading section 21 judges. Give to 22. In this embodiment, as will be described later, the data of the most similar day within the last 10 days of the latest day is read, and it is determined that there is no abnormality.
Further, when the determination section is executed, the data of the most similar day within the 20 days before and after the latest one year before is read out.

The judging section 22 compares the latest data of the day with the data of the day in which the situation is similar, and when the power generation pattern and the peak power generation amount are clearly decreased, it is judged as abnormal. The determination is made and the determination output is given to the display unit 23, and this determination is made every time new data is obtained.

FIG. 4 is a flow chart for explaining the operation of the solar cell abnormality detecting device having the above configuration.

First, the Y, Z, X year (for example, 1
Data measured on January 18th)
Date (October 8, 1993) to Year X, Year X Z-1 (Heisei 5
(October 17, 2016) and compare it with the data on the day when the measurement situation was similar (step n1), and judge that the power generation amount has clearly decreased. If so, it is determined that some abnormality has occurred in the solar cell within the past few days, and a message to that effect is displayed (step n).
4).

When it is determined in step n1 that the amount of power generation has not decreased, Y, Y, Z year X
Data measured on (October 18th) and Y-1 / X-Y year X-1
From 10th (October 8th, 1992) to X-1 year Y month Z + 10
Day (October 28, 1992) by comparing with the data of the day when the measurement situation is similar, it is judged whether or not the power generation amount is obviously decreased (step n2), and it is obviously decreased. If it is determined that the power generation amount is lower than that of one year ago due to deterioration of the solar cell, a message to that effect is displayed (step n5).

When it is determined in step n2 that the power generation amount does not decrease, it is determined that the solar cell is normal, and the process ends.

The above processing is carried out each time data for one day is obtained.

As described above, the power generation amount data measured every day and the measured conditions, for example, the condition data indicating the weather, temperature, sunshine duration, etc. are stored in the memory 19, and the newly measured power generation amount is also stored. Whether or not there is an abnormality is determined by comparing the data with the power generation amount data of the previous day, which is measured in a situation similar to that of the power generation amount data and is already stored in the memory 19. ,the weather,
Since the presence or absence of abnormality of the solar cell is determined by comparing the power generation amount data measured when the conditions such as temperature or sunshine time are similar, without being affected by changes in conditions such as weather, temperature or sunshine time, It is possible to reliably detect abnormalities such as aging deterioration of the solar cell, failure, or adhesion of an object (fallen leaves or bird droppings) to the surface of the solar cell arranged outdoors.

In the above-described embodiment, the presence or absence of abnormality of the solar cell is determined on a day-by-day basis.
The present invention need not necessarily be on a daily basis, for example,
The data may be averaged on a weekly basis for determination.

In the above embodiment, the abnormality detecting device for the solar cell is provided separately from the protection device or the inverter, but as another embodiment of the present invention, it may be provided integrally with the protection device or the inverter.

Although the above embodiments have been described by applying to the system interconnection system of the distributed power source and the commercial power source, the present invention is not limited to such a system and can be applied to other solar power generations. Of course.

[0032]

As described above, according to the present invention, the measured power generation data of the solar cell and the measured condition, for example,
The situation data indicating the weather and the like are sequentially stored in the storage means, and the newly measured power generation amount data and the power generation which is measured in the situation corresponding to the situation in which the power generation amount data is measured and is already stored in the storage means Since it determines whether or not there is an abnormality in the solar cell by comparing it with the amount data, it will be determined by comparing the power generation amount data measured under similar conditions, and therefore changes in conditions such as weather and temperature. It is possible to reliably determine the abnormality of the solar cell without being affected by.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a system to which an embodiment of the present invention is applied.

FIG. 2 is a functional block diagram of the embodiment shown in FIG.

FIG. 3 is a diagram showing a difference in power generation pattern due to weather.

FIG. 4 is a flowchart for explaining the operation.

[Explanation of symbols]

 8 Solar Cell 14 Solar Cell Abnormality Detection Device 19 Memory 22 Judgment Section

Claims (3)

[Claims] 1. A storage unit for sequentially storing power generation amount data of a solar cell, which is sequentially measured in a unit of a fixed period, together with status data indicating a status of the measured fixed period, and a measured solar of a fixed period. It is determined whether or not there is an abnormality in the solar cell by comparing the power generation amount data of the battery and the power generation amount data measured in a situation corresponding to the situation in which the power generation amount data is measured and already stored in the storage means. An abnormality detecting device for a solar cell, comprising: 2. The abnormality detecting device for a solar cell according to claim 1, wherein the fixed period is one day, the power generation amount data is a peak power generation amount, and the situation data includes weather data. 3. The fixed period is one day, and the power generation amount data is a power generation pattern showing a change in the power generation amount of one day.
The abnormality detecting device for a solar cell according to claim 1, wherein the situation data includes weather data.