JP2022177517A - Photovoltaic system management device - Google Patents

Abstract

A photovoltaic power generation system management device that facilitates optimization of power generation loss due to weeds and weeding costs is provided. A management device for a photovoltaic power generation system having a first photovoltaic power generation section and a second photovoltaic power generation section where shadows of weeds are more likely to fall on the power generation surface than the first photovoltaic power generation section. , an information acquisition unit 12 that acquires first information that is information related to the amount of power generation in the first solar power generation unit, and second information that is information related to the amount of power generation in the second solar power generation unit; A comparison unit 14 that compares the first information and the second information and calculates the degree of power generation loss, which is the degree of decrease in the amount of power generation due to weeds, the calculated degree of power generation loss, and the weeding cost required to remove the predetermined weeds. and a proposing unit 16 for obtaining a weeding day, which is a day for removing weeds, based on the above. [Selection diagram] Fig. 2

Description

The present invention relates to a photovoltaic system management device.

2. Description of the Related Art In a photovoltaic power generation system, it is required to secure an amount of power generation in order to improve business profitability (see Patent Document 1, for example).

JP 2019-208350 A

Patent Literature 1 mentions weeds and shadows of buildings as causes for lowering the amount of power generated by a photovoltaic power generation system. Specifically, it is described that when a shadow falls on the solar panels of a solar power generation system, the amount of power generated decreases.

The decrease in the amount of power generation due to the shadow of the building is determined by the positional relationship between the building and the solar panel. Therefore, measures against shadows of buildings are taken at the time of construction of buildings or at the time of installation of solar panels. After the countermeasures are taken, there is no increase in the decrease in power generation due to shadows of buildings.

On the other hand, when weeds grow thick around the solar panels placed near the ground surface, the shadow of the weeds reduces the amount of power generation. As for the shade of weeds, measures are taken to remove the weeds to prevent a decline in power generation.

However, even if weeds are removed, the weeds will grow again, and the shadow of the weeds will again reduce the amount of power generation. In other words, regular weeding is necessary to prevent a decrease in power generation. There is a problem that the cost of this weeding is a heavy burden on power generation companies.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a photovoltaic power generation system management device that facilitates optimization of power generation loss due to weeds and weeding costs.

In order to achieve the above object, the present invention provides the following means.
A photovoltaic power generation system management device of the present invention includes a first photovoltaic power generation unit and a second photovoltaic power generation unit where shadows of weeds are more likely to fall on the power generation surface than the first photovoltaic power generation unit. A power generation system management device that acquires first information that is information related to the power generation amount of the first solar power generation unit and second information that is information related to the power generation amount of the second solar power generation unit. an information acquisition unit that compares the acquired first information and the second information and calculates a power generation loss degree that is a degree of decrease in power generation amount due to the weeds; the calculated power generation loss degree; and a proposing unit that obtains a weeding day, which is the day on which the weeds are to be removed, based on a predetermined weeding cost required to remove the weeds.

According to the solar power generation system management device of the present invention, the weeding day to be proposed to the manager of the solar power generation system is determined based on the degree of power generation loss and the weeding cost. Specifically, based on the degree of power generation loss based on information on the power generation amount of the first solar power generation unit and the second solar power generation unit, which differ in the ease with which weed shadows fall on the power generation surface, the power generation amount decreases and Decrease in electricity sales profit is calculated based on the electricity sales unit price set in advance, and compared with the weeding cost, the date of weeding is obtained. Therefore, compared to methods based on weather information and solar radiation, this power generation loss degree can more accurately calculate the decrease in power generation, making it easier to find a more appropriate weeding day.

In the above invention, the comparison unit includes a power conditioner connected to a first time period when a shadow of an object other than the weeds falls on the power generation surface, and to the first solar power generation unit and the second solar power generation unit. It is preferable that the power generation loss degree is calculated excluding the second time period in which the control is changed.

By calculating the degree of power generation loss excluding the first time period and the second time period in this way, compared to the case where the first time period and the second time period are not excluded, It is easy to obtain the degree of power generation loss.

In the above invention, the storage unit stores the power generation loss degree obtained by the comparison unit, and the subsequent value of the power generation loss degree is estimated based on the transition of the power generation loss degree stored in the storage unit. and an estimating unit, wherein the proposing unit obtains the weeding date using the power generation loss degree estimated by the estimating unit instead of the power generation loss degree calculated by the comparing unit. preferable.

By obtaining the weeding day based on the subsequent power generation loss degree estimated by the estimation unit in this way, it is easier to increase the appropriateness of the obtained weeding day compared to the case where the weeding day is not based on the estimated power generation loss degree.

In the above invention, the estimating unit estimates the subsequent power generation loss degree value based on weather data including weather information in an area where the first solar power generation unit and the second solar power generation unit are installed. is preferred.

By estimating the degree of power generation loss thereafter based on the weather data in this manner, the degree of power generation loss including the growth of weeds that change with weather conditions can be obtained. Therefore, it is easier to obtain a power generation loss degree with higher accuracy than when it is not based on meteorological data.

According to the solar power generation system management device of the present invention, the weeding day to be proposed to the manager of the solar power generation system is obtained based on the degree of power generation loss and the weeding cost. It is effective in facilitating optimization with

BRIEF DESCRIPTION OF THE DRAWINGS It is a model drawing explaining the structure of the photovoltaic power generation system which concerns on one Embodiment of this invention. 2 is a block diagram for explaining the configuration of a management device in FIG. 1; FIG. It is a flowchart explaining the process which calculates|requires the power generation loss degree of a management apparatus. FIG. 4 is a diagram showing the relationship between output currents of a first string and a second string; It is a flowchart explaining the process which estimates the weeding day of a management apparatus. FIG. 4 is a diagram showing an example of an estimated power generation loss degree; FIG. 5 is a diagram showing another example of estimated power generation loss degree;

A management device for a photovoltaic power generation system according to one embodiment of the present invention will be described with reference to FIGS. 1 to 7. FIG. As shown in FIG. 1, the management device 10 of the present embodiment is a device that measures the amount of power generated in the solar power generation system 50 for each string 51 and optimizes power generation loss due to weeds and weeding costs.

In the present embodiment, the first string (first solar power generation unit) 51A and the second string 51A are based on the ease with which weeds cast shadows on the power generation surface of the strings 51 (hereinafter also referred to as the degree of influence of weeds). (Second photovoltaic power generation unit) 51B, and will be described. The weed influence degree is determined in advance for each string 51 and stored in the storage unit 17 described later in association with the corresponding string 51 .

In the present embodiment, a string 51 with a relatively low weed influence is classified as a first string 51A, and a string 51 with a relatively high weed influence is classified as a second string 51B. .

In addition, the first string 51A and the second string 51B are arranged at positions where conditions other than shadows by weeds are similar, in other words, positions close to each other. For example, they are arranged in the same photovoltaic system 50 .

By arranging the first string 51A and the second string 51B close to each other, the difference in conditions that affect the amount of power generation, such as the amount of solar radiation and temperature, becomes smaller than when they are arranged at distant positions.

The classification of the first strings 51A and the second strings 51B is performed in the grouping section 13, which will be described later. Henceforth, when there is no need to distinguish between the first string 51A and the second string 51B, they will simply be referred to as the string 51 as well.

As a method of determining the weed influence degree, a method based on the height of the power generation surface of the string 51, in other words, the distance from the ground to the power generation surface can be exemplified. If the distance from the ground to the power generation surface is short, the weed influence will be high. The longer the distance from the ground to the power generation surface, the lower the weed influence.

Here, the photovoltaic power generation system 50 has a configuration in which a plurality of strings 51 are connected in parallel. The string 51 has a structure in which a plurality of solar panels 52 are electrically connected in series. The solar panel 52 is also called a solar module.

A solar panel 52 is composed of a plurality of clusters 53 . The cluster 53 is composed of a plurality of cells (also referred to as elements) 54 that generate power from incident sunlight. Note that the photovoltaic power generation system 50 may have any known configuration, and is not limited to any specific configuration.

In this embodiment, an example in which three strings 51 are provided in the photovoltaic power generation system will be described. is not limited to

As shown in FIG. 2, the management device 10 of the photovoltaic power generation system 50 includes a processor having a CPU (Central Processing Unit), ROM, RAM, input/output interfaces, etc., a microcomputer, a personal computer, a server, and the like. Information processing equipment.

The program stored in the storage device such as the above-mentioned ROM cooperates with the CPU, ROM, RAM, and input/output interface to at least the communication unit 11, the information acquisition unit 12, the grouping unit 13, the comparison unit 14, and the simulation unit. It functions as (estimation unit) 15 , proposal unit 16 , storage unit 17 , data output unit 18 and display unit 19 .

The communication unit 11 is an interface connected to the measurement unit 31 and the weather database 35 so as to be able to communicate information. The communication unit 11 is connected to the measurement unit 31 and the weather database 35 using known wired or wireless information communication means.

The measurement unit 31 is a sensor that measures the amount of power generated, which is the amount of power output from the string 51 . Information on the power generation amount measured by the measurement unit 31 is output to the communication unit 11 of the management device 10 . In the present embodiment, an example will be described in which the measurement unit 31 is a known sensor capable of measuring electric energy, and the information related to the amount of power generation is the value of the output electric energy.

Note that the measurement unit 31 may be a known sensor capable of measuring current or voltage, and the information related to the amount of power generation may be the value of the output current or the value of the output voltage. The measurement unit 31 may be a known sensor that measures the intensity of solar radiation, and the information related to the amount of power generation may be the value of the intensity of solar radiation.

The weather database 35 is a database in which weather data including weather information in the area where the string 51 is installed is stored. The meteorological data may be data provided by the Japan Meteorological Agency, or data acquired by various sensors placed in the area where the string 51 is installed.

The information acquisition unit 12 is a device that performs processing for acquiring information related to the power generation amount in the string 51 via the communication unit 11 . The acquired information related to the power generation amount includes first information related to the power generation amount in the first string 51A and second information related to the power generation amount in the second string 51B.

The grouping unit 13 groups each of the plurality of strings 51 into a group of first strings 51A and a group of second strings 51B based on the weed influence degree stored in the storage unit 17. Department.

The comparison unit 14 is a processing unit that compares the first information of the first string 51A acquired by the information acquisition unit 12 and the second information of the second string 51B to calculate the degree of power generation loss. The degree of power generation loss is a value that indicates the degree to which the power generation amount of the string 51 has decreased due to weeds. A specific processing content for calculating the power generation loss degree in the comparison unit 14 will be described later. The power generation loss degree calculated by the comparison unit 14 is stored in the storage unit 17 .

The simulation unit 15 is a processing unit that estimates the subsequent value of the power generation loss degree based on the transition of the power generation loss degree stored in the storage unit 17 . The details of processing for estimating the value of the power generation loss degree in the simulation unit 15 will be described later. The power generation loss degree estimated by the simulation unit 15 is output to the proposal unit 16 .

The proposing unit 16 is a processing unit that obtains a weeding day, which is a day to remove weeds, based on the degree of power generation loss estimated by the simulation unit 15 and a predetermined weeding cost required to remove weeds. The details of processing for determining the weeding day in the proposal unit 16 will be described later. Information on the date of weeding estimated by the proposal unit 16 is output to the data output unit 18 .

The storage unit 17 is a device that stores at least the weed influence degree of the plurality of strings 51 , the power generation loss degree calculated by the comparison unit 14 , and the weather data acquired from the weather database 35 . It is also a device that outputs the stored power generation loss degree and the stored weather data to the simulation unit 15 .

The data output unit 18 is a device that outputs information on the date of weeding estimated by the proposal unit 16 to the display unit 19 . The data output unit 18 is connected to the display unit 19 by wire or wirelessly so that information can be communicated.

The display unit 19 is a device that presents the weeding day information output from the data output unit 18 . In this embodiment, an example in which the display unit 19 is a liquid crystal display screen will be described. Note that the display unit 19 may be a known device that presents information other than the liquid crystal display screen. Moreover, the display unit 19 may be formed integrally with the management device 10 or may be formed separately from the management device 10 .

Next, weeding date estimation processing in the management device 10 of the photovoltaic power generation system 50 having the above configuration will be described. Here, the processing for obtaining the power generation loss degree used for estimating the weeding date and the processing for estimating the weeding date based on the power generation loss degree will be described separately.

The processing for obtaining the degree of power generation loss is continuously performed throughout the operating period of the photovoltaic power generation system 50 . On the other hand, the process of estimating the date of weeding is performed at predetermined intervals.

First, the processing for obtaining the degree of power generation loss will be described with reference to FIG. When the processing in the management device 10 is started, the management device 10 performs processing to determine whether it is within the operating period of the photovoltaic power generation system 50 (S11). If it is determined to be outside the operating period (in the case of NO), the determination process of S11 is performed again.

Examples of the operating period include a time zone during which the string 51 generates power (a time zone from sunrise to sunset), and a period during which the string 51 is installed and capable of generating power.

When it is determined to be within the operating period in the determination process of S11 (in the case of YES), the information acquisition unit 12 performs a process of acquiring information related to the power generation amount (S12). Specifically, the information acquisition unit 12 performs a process of acquiring information related to the amount of power generation of the string 51 measured by the measurement unit 31 via the communication unit 11 .

After obtaining the information related to the power generation amount, the grouping unit 13 performs grouping processing (S13). Specifically, the grouping unit 13 performs a process of acquiring the weed influence degree stored in the storage unit 17 . Information specifying the corresponding string 51 is associated with the weed influence degree.

The grouping unit 13 performs a process of classifying the string 51 with a relatively small degree of influence of weeds associated therewith into the first string 51A. In addition, processing is performed to classify the linked string 51 having a relatively high weed influence degree into the second string 51B. An arbitrarily determined value can be used as the threshold used for classification.

Hereinafter, among the information related to the power generation amount of the string 51, the information related to the power generation amount of the first string 51A will be referred to as first information, and the information related to the power generation amount of the second string 51B will be referred to as second information. do.

After the grouping process is performed, the comparison unit 14 performs a process of calculating the degree of power generation loss (S14). In this embodiment, the comparison unit 14 compares the first information of the first string 51A acquired by the information acquisition unit 12 and the second information of the second string 51B to calculate the degree of power generation loss.

The degree of power generation loss is a parameter that expresses the power generation amount with respect to the reference, with the power generation amount in a state where the shadow of weeds does not fall on the power generation surface of the string 51 as a reference. In this embodiment, an example of calculating the power generation loss degree of the second string 51B with the first string 51A as a reference will be described.

FIG. 4 shows an example of the relationship between the first information of the first string 51A and the second information of the second string 51B. FIG. 4 shows an example in which the first information of the first string 51A is the output current and the second information of the second string 51B is the output current.

In FIG. 4, hatched circles indicate the data Db before weeding, and white circles indicate the data Da after weeding. In the data Db affected by the weed shadow, the output current of the second string 51B is lower than that of the first string 51A. The output current of the second string 51B is equivalent to that of the first string 51A with the data Da without the shadow of weeds.

Therefore, comparing the power generation loss after weeding before weeding, which is affected by the shadow of weeds, and after weeding, which is not affected by the shadow of weeds, increases. Also, the power generation loss degree before weeding, which is influenced by the shadow of weeds, tends to be calculated as a value smaller than one. After weeding without the influence of shadows of weeds, the degree of power generation loss tends to be calculated as a value of about 1.

The comparison unit 14 further performs a process of calculating the power generation loss degree in time periods other than the first time period and the second time period. The first time period is a time period in which shadows of objects other than weeds fall on the power generating surface of the string 51 . The second time period is the time period when the power conditioner connected to the string 51 changed control. In this embodiment, an example will be described in which the second time period is a time period in which the voltage output from the string 51 is changed from the maximum power point.

When the power generation loss degree is calculated, the storage unit 17 performs processing for storing the calculated power generation loss degree (S15). In the power generation loss degree, information on the date and time when information related to the corresponding amount of power generation was acquired and information specifying the corresponding string 51 are linked and stored.

After the power generation loss degree is stored, a process of determining whether it is outside the operating period of the photovoltaic power generation system 50 is performed (S16). If it is determined that it is not outside the operating period (in the case of NO), the process returns to S11 and the above-described processing is repeated. If it is determined that it is outside the operating period (if YES), the processing for obtaining the degree of power generation loss ends.

Next, the processing for estimating the date of weeding will be described with reference to FIG. When the processing in the management device 10 is started, the management device 10 performs processing for determining whether it is time to estimate the weeding day (S21). If it is determined that it is not the time to estimate the date of weeding (in the case of NO), the determination process of S21 is performed again.

When it is determined that it is time to estimate the date of weeding (in the case of YES), the simulation unit 15 performs a process of acquiring the degree of power generation loss (S22). When the power generation loss degree is acquired, the simulation unit 15 performs a process of acquiring weather data (S23). The weather data to be acquired includes items that affect power generation, such as temperature, humidity, wind speed, amount of rainfall, and amount of clouds in the area where the photovoltaic power generation system 50 is located.

When the weather data is acquired, the simulation unit 15 performs processing for estimating the value of the power generation loss degree (S24). The simulation unit 15 estimates the subsequent power generation loss degree value based on the change in the power generation loss degree stored in the storage unit 17, the weather data, and the weeding date.

The simulation unit 15 estimates the value of the degree of power generation loss and the value of the power generation amount when the conditions such as the date of weeding are changed. As a method for estimating the value of the power generation loss degree, a known method such as a method using regression analysis or a method using a neural network can be used.

FIG. 6 is a diagram showing an example of the degree of power generation loss estimated by the simulation unit 15. As shown in FIG. The horizontal axis is the month, and the vertical axis is the degree of power generation loss. In FIG. 6, weeding days Hd are provided in June, September, and November of 2020. It is estimated that the value of the power generation loss degree decreases due to the growth of weeds during the period between the weeding days Hd.

From January to June 2020, weeds have not grown enough to cast a shadow on the power generation surface, so it is estimated that the value of the power generation loss degree will not decrease. Also, the value of the power generation loss degree may be 1 or more. This is because sunlight may be reflected by weeds and the amount of solar radiation incident on the power generation surface may increase.

FIG. 7 is a diagram showing another example of the degree of power generation loss estimated by the simulation unit 15. In FIG. The horizontal axis is the month, and the vertical axis is the degree of power generation loss. In FIG. 7, weeding days Hd are provided in April, July, and November 2020. In FIG.

In addition, Typhoon Ty passed in October 2019. When typhoon Ty passes through, weeds tend to fall over due to strong winds, so it is presumed that the weeds are less likely to cast shadows on the power generation surface. In other words, it is estimated that the speed at which the power generation loss degree decreases becomes slower.

After estimating the value of the power generation loss degree, the proposal unit 16 performs a process of determining the date of weeding (S25). The proposing unit 16 obtains a weeding day, which is a day for weeding, based on the degree of power generation loss estimated by the simulation unit 15 and a predetermined weeding cost required to remove weeds.

Examples of methods for determining the weeding day include a method of selecting a weeding day on which both the degree of power generation loss and the weeding cost are low, and a method of selecting a weeding day on which the weeding cost is the lowest.

When the date of weeding is obtained, the management device 10 performs processing for displaying the date of weeding (S26). The manager of the photovoltaic power generation system 50 determines the weeding day based on the weeding day obtained by the management device 10 . This completes the processing for estimating the date of weeding.

According to the management device 10 configured as described above, the weeding day to be proposed to the administrator of the photovoltaic power generation system 50 is obtained based on the degree of power generation loss and the weeding cost. Specifically, based on the degree of power generation loss based on information on the power generation amounts of the first strings 51A and the second strings 51B, which differ in the ease with which weed shadows fall on the power generation surface, the power generation amount is reduced and the preset Decrease in electricity sales profit based on electricity sales unit price is calculated and compared with weeding cost to obtain weeding day.

Therefore, compared to methods based on weather information and solar radiation, this power generation loss degree can more accurately calculate the decrease in power generation, making it easier to find a more appropriate weeding day. In other words, it is easy to obtain a weeding day on which the power generation amount and the weeding cost are well balanced.

By calculating the power generation loss degree excluding the first time period and the second time period, the power generation loss degree due to the shadow of weeds is compared with the case where the first time period and the second time period are not excluded. easy to find.

By determining the weeding day based on the subsequent power generation loss degree estimated by the simulation unit 15, it is easier to improve the appropriateness of the determined weeding day compared to the case where it is not based on the estimated power generation loss degree.

By estimating the degree of power generation loss after that based on the weather data, the degree of power generation loss including the growth of weeds that change with weather conditions can be obtained. Therefore, it is easier to obtain a power generation loss degree with higher accuracy than when it is not based on meteorological data.

The technical scope of the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention.

10 Management device 12 Information acquisition unit 14 Comparison unit 15 Simulation unit (estimation unit) 16 Proposal unit 17 Storage unit 50 Solar power generation system 51A First string (first solar power generation section), 51B... 2nd string (second solar power generation section)

Claims (4)

A management device for a photovoltaic power generation system having a first photovoltaic power generation unit and a second photovoltaic power generation unit in which shadows of weeds are more likely to fall on a power generation surface than the first photovoltaic power generation unit,
an information acquisition unit that acquires first information that is information related to the power generation amount of the first solar power generation unit and second information that is information related to the power generation amount of the second solar power generation unit;
a comparison unit that compares the acquired first information and the second information and calculates a power generation loss degree, which is a degree of decrease in the amount of power generation due to the weeds;
a proposal unit that obtains a weeding day, which is a day for removing the weeds, based on the calculated degree of power generation loss and a predetermined weeding cost required to remove the weeds;
A solar power generation system management device provided with. The comparison unit controls a power conditioner connected to the first photovoltaic power generation unit and the second photovoltaic power generation unit during a first time period when a shadow of an object other than the weeds falls on the power generation surface. The photovoltaic power generation system management device according to claim 1, wherein the power generation loss degree is calculated excluding the changed second time period. a storage unit that stores the degree of power generation loss obtained by the comparison unit;
an estimating unit for estimating a subsequent value of the power generation loss degree based on the transition of the power generation loss degree stored in the storage unit,
The photovoltaic power generation system according to claim 1 or 2, wherein the proposing unit obtains the weeding date using the power generation loss degree estimated by the estimation unit instead of the power generation loss degree calculated by the comparison unit. management device. 4. The estimation unit according to claim 3, wherein the estimation unit estimates the subsequent power generation loss degree value based on weather data including weather information in an area where the first solar power generation unit and the second solar power generation unit are installed. solar power generation system management equipment.

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