JPWO2019163414A1 - Photovoltaic power generation failure judgment device, photovoltaic power generation failure judgment method, program - Google Patents

Abstract

SOLUTION: An acquisition unit that acquires various amount information indicating various amounts of electricity output from each of a plurality of solar cells, and the plurality of units at a predetermined time in a predetermined period in the past based on the amount information. Of the various amounts of electricity output from a predetermined specific solar cell among the solar cells of the above, the first electric amounts showing a predetermined value are extracted, and the electricity output from each of the plurality of solar cells. Of the various quantities, at the predetermined time, an extraction unit that extracts the second electrical quantity showing a predetermined value, a calculation unit that calculates the third electrical quantity based on the plurality of the second electrical quantity, and the predetermined time. , A comparison unit that compares the ratio of the first electricity amount to the third electricity amount and the first threshold value, and a predetermined situation based on the comparison result compared by the comparison unit in the past predetermined period. It is provided with a determination unit for determining whether or not the continuation time exceeds the second threshold value and determining the state of the specific solar cell based on the determination result. [Selection diagram] Fig. 1

Description

The present invention relates to a photovoltaic power generation failure determination device, a photovoltaic power generation failure determination method, and a program.

For example, a system for diagnosing a failure of a solar cell string is known.

Japanese Unexamined Patent Publication No. 2016-149832

In Patent Document 1, a time zone in which the amount of change in solar radiation is stable is selected when determining a failure, and whether the difference between the maximum value and the minimum value of the amount of solar radiation in the selected time zone is larger than a predetermined value. A system for determining whether or not to start a failure diagnosis by determining whether or not to perform is disclosed.

However, in this technique, when the threshold value for the time that is the reference for determining the time when the amount of solar radiation is stable is shortened, it is determined that the amount of solar radiation is stable even if it is affected by the shadow. In the subsequent processing, there is a risk of erroneously determining that the solar cell string has failed even though it has not failed.

The main invention that solves the above-mentioned problems is an acquisition unit that acquires various amount information indicating various amounts of electricity output from each of a plurality of solar cells, and based on the various amount information, in a predetermined period in the past. At a predetermined time, among the electric quantities output from the predetermined specific solar cells among the plurality of solar cells, the first electric quantity showing a predetermined value is extracted, and the plurality of solar cells An extraction unit that extracts a second electric amount showing a predetermined value from the electric amounts output from each, and a calculation unit that calculates a third electric amount based on a plurality of the second electric amounts. And a comparison unit that compares the ratio of the first electrical quantity to the third electrical quantity and the first threshold value at the predetermined time, and a comparison that is compared by the comparison unit in the past predetermined period. A determination unit for determining whether or not the duration of the predetermined situation exceeds the second threshold based on the result and determining the state of the specific solar cell based on the determination result is provided.

Other features of the invention will become apparent with reference to the accompanying drawings and the description herein.

According to the present invention, it is possible to realize an appropriate failure determination in which a temporary change due to a shadow or the like is not determined as a failure.

It is a figure which shows an example of the structure of a photovoltaic power generation system. It is a figure which conceptually shows the communication state between a string monitoring device and a management device. It is a figure which shows an example of the structure of the string monitoring apparatus. It is a figure which shows an example of the hardware composition of the 1st communication device. It is a figure which shows an example of the software structure of the 1st communication apparatus. It is a figure which shows an example of the hardware configuration of a management device. It is a figure which shows an example of the software structure of the 2nd communication device. It is a figure which shows an example of the hardware composition of the photovoltaic power generation failure determination apparatus. It is a figure which shows an example of the software structure of the photovoltaic power generation failure determination apparatus. It is a table which shows an example of the string monitoring apparatus arrangement management table. It is a table which shows an example of the electric quantity table. It is a table which shows an example of the extraction table. It is a table which shows an example of the average electric quantity table. It is a flow chart which shows an example of the operation procedure of the photovoltaic power generation failure determination apparatus in this embodiment. It is a 1st graph which plotted the current of a predetermined string in a predetermined period. It is a 2nd graph which extracted and plotted the maximum value of the current of a predetermined string in a predetermined period. It is a flow chart which shows another example of the operation procedure of the photovoltaic power generation failure determination apparatus in this embodiment. It is a 3rd graph which plotted the voltage of a predetermined string in a predetermined period. It is a 4th graph which extracted and plotted the minimum value of the voltage of a predetermined string in a predetermined period.

The description of the present specification and the accompanying drawings will clarify at least the following matters. In addition, it should be noted
In FIGS. 1 to 19, the same items will be described with the same numbers.

=== Configuration of photovoltaic power generation system 100 ===
The photovoltaic power generation system 100 in which the photovoltaic power generation failure determination device 10 determines a failure will be described with reference to FIGS. 1 and 2.

FIG. 1 is a diagram showing an example of the configuration of the photovoltaic power generation system 100. As shown in FIG.
The photovoltaic power generation system 100 is, for example, a power conditioner 110 (PCS: Power Co.
nditioning System), current collector box 120, junction box 121, and solar cell panels 131,1
String 130 composed of 32 and string monitoring device 140 (SSU: String Sen)
sor Unit), management device 150 (MU: Management Unit), and network device 160
(NW: Network Device) and is configured to include.

The power conditioner 110 is a device that converts the electric power transmitted from the current collector box 120 from direct current to alternating current. The electric power output from the power conditioner 110 is supplied to the electric power system.

The current collector box 120 is a member to which a plurality of junction boxes 121 are electrically connected. Junction box 121
Is a member to which a plurality of strings 130 are electrically connected. The DC power transmitted from each string 130 is transmitted to the power conditioner 110 via the junction box 121 and the current collector box 120.

The string 130 is a unit of a solar cell panel formed by connecting a plurality of solar cell panels 131 and 132 in series. In FIG. 1, the solar cell panel 131 shows a solar panel in which the string monitoring device 140 is installed, and the solar cell panel 132 shows a solar panel in which the string monitoring device 140 is not installed. In addition, FIGS. 1 to 2
At 0, a number such as "1-1-1" attached to the string 130 indicates a string ID which is an identifier uniquely identifying each string 130, and in the following, for example, "1-1-1". The string 130 of the number may be described as "1-1-1 string 130". In addition, a plurality of strings 130 connected to the junction box 121 may be collectively referred to as all strings 130. Solar panel 131,1
32 is composed of a plurality of solar cell panels in which the light receiving surfaces are arranged in a plane facing upward and the surface side is protected by resin, tempered glass, or the like.

The string monitoring device 140 measures or calculates the current, voltage, or impedance (hereinafter, referred to as “electrical quantities”) of a predetermined string 130, and has a function of wirelessly communicating with another string monitoring device 140 and the management device 150. Has. As shown in FIG.
The string monitoring device 140 is connected between a plurality of solar cell panels connected in series. Thereby, the current flowing in the string 130 and the voltage in the string 130 can be measured. The first communication device 144 of the string monitoring device 140 transmits various quantity information indicating the measured electric quantities to the management device 150. The configuration of the string monitoring device 140 will be described in detail later.

The management device 150 is a device that transfers various quantity information received from the string monitoring device 140 to the photovoltaic power generation failure determination device 10 via the network device 160. Management device 150
The configuration of is described in detail later.

The management device 150 constitutes, for example, a multi-hop wireless communication network (hereinafter, referred to as “multi-hop network”) with the string monitoring device 140. In a multi-hop network, for example, radio waves in a frequency band such as 2.4 GHz band or 920 MHz band are used, and communication is performed in accordance with a wireless communication standard such as IEEE802.15.4. The optimum frequency band and wireless communication standard are appropriately selected according to the reach of radio waves, the distance between adjacent string monitoring devices 140, and the like. The connection form of the multi-hop network is not necessarily limited, for example, a tree type in which the string monitoring device 140 is hierarchically connected with the management device 150 as the root, and a star type in which a plurality of string monitoring devices 140 are directly connected to the management device 150. ..

FIG. 2 is a diagram conceptually showing the communication status between the string monitoring device 140 and the management device 150. As shown in FIG. 2, the management device 150 and the string monitoring device 140 have a management device ID and a string monitoring device ID, which are identifiers uniquely identified in the multi-hop network in order to construct the multi-hop network. It is given to each. The management device ID and the string monitoring device ID are, for example, physical addresses uniquely assigned to each, for example, a MAC address. The management device 150 and the string monitoring device 140 store the management device ID and the string monitoring device ID assigned to them, respectively.

Although the management device 150 and the string monitoring device 140 are described as wireless communication in the present embodiment, a network may be constructed by wired communication using a communication cable such as an optical cable.

The network device 160 is a device for connecting the management device 150 to the network 170. The network device 160 is a wired or wireless relay device, such as a switching hub or a router. The network 170 is, for example, the Internet or a dedicated line, and the photovoltaic power generation failure determination device 10 and the network device 160 are communicably connected via the network 170. The network device 160 may be, for example, a power plant monitoring device or a monitoring camera having a relay function.

In the above description, it has been described that the photovoltaic power generation failure determination device 10 is connected to the management device 150 via the network 170 and the network device 160, but the present invention is not limited to this. For example, the photovoltaic power generation system 100 may be configured such that the photovoltaic power generation failure determination device 10 receives various amounts of information directly from the management device 150 without going through the network 170 and the network device 160. In this case, the photovoltaic power generation failure determination device 10
For example, it is provided in the enclosure 180. Even in this case, the network is not limited to wireless communication, and may be constructed by a wired communication network using a communication cable such as an optical cable.

Hereinafter, the string monitoring device 140, the management device 150, and the photovoltaic power generation failure determination device 10 in the present embodiment will be described in detail.

== Configuration of string monitoring device 140 ==
The string monitoring device 140 will be described as follows with reference to FIGS. 3, 4, and 5.

FIG. 3 is a diagram showing an example of the configuration of the string monitoring device 140. As shown in FIG.
The string monitoring device 140 includes a voltage detector 141, a current detector 142, an AD converter 143, and a first communication device 144. The string monitoring device 140 is supplied with drive power from the current lines (positive side line and negative side line) of the string 130. The string monitoring device 140 may be provided with an emergency auxiliary power supply.

The voltage detector 141 is provided to measure, for example, the voltage value between the positive side line and the negative side line of the current line. The voltage detector 141 has, for example, a circuit that amplifies the measured voltage value (analog signal) and outputs it to the AD converter 143.

The current detector 142 has, for example, an element that detects a current flowing through a current line, and has a circuit that amplifies the detected current value (analog signal) and outputs it to the AD converter 143.

The AD converter 143 is a device that converts an analog signal indicating various amounts of electricity (voltage value, current value) input from each of the voltage detector 141 and the current detector 142 into a digital signal and outputs the analog signal to the first communication device 144. Is.

The first communication device 144 is a device for communicating with the management device 150 and other string monitoring devices 140 via a multi-hop network. FIG. 4 is a diagram showing an example of the hardware configuration of the first communication device 144. As shown in FIG. 4, the hardware of the first communication device 144 includes a processor 1441, a memory 1442, a timing device 1443, and a communication circuit 14.
44 and. The processor 1441 is, for example, an MPU (Micro Process i).
ng Unit), CPU (Central Processing Unit), etc. The memory 1442 includes, for example, a RAM (Random Access Memory), a ROM (Read Only Memory), and an NVRAM (Non Vo).
latile RAM) and so on. The processor 1441 and the memory 1442 are the first communication device 1.
44 has a role to function as an information processing device. Programs and data such as firmware are stored in the memory 1442. The timekeeping device 1443 is, for example, RTC (
It is configured using Real Time Clock) and outputs time information. The communication circuit 1444
For example, it includes a high-frequency amplifier circuit, a modulation / demodulation circuit (frequency conversion circuit, filter circuit, oscillation circuit, orthogonal demodulation circuit, orthogonal modulation circuit, etc.), an AD converter, a DA converter, and the like.

FIG. 5 is a diagram showing an example of the software configuration of the first communication device 144. As shown in FIG. 5, the software of the first communication device 144 can realize the functions of the multi-hop communication unit 144a and the various quantity information transmission unit 144b. These functions are, for example, the first communication device 144.
This is realized by the processor 1441 of the above reading and executing the program stored in the memory 1442. Note that these functions may be realized by hardware such as ASIC.

The multi-hop communication unit 144a is a function for communicating with other string monitoring devices 140 and management devices 150 via a multi-hop network. The multi-hop communication unit 144a includes, for example, a route control function, an access control function, a channel estimation / allocation function, an error control function, a flow control function, a congestion control function, a QoS management function, and the like for performing communication. When the multi-hop communication unit 144a receives a packet of a destination other than itself via the multi-hop network, for example, the route control function selects a route, and the received packet is selected by another string monitoring device 140 on the selected route. And has a function of transferring to the management device 150.

The quantity information transmission unit 144b is a function for transmitting the electrical quantities input from the AD converter 143 as quantity information to the management device 150 via the multi-hop network.
The quantity information transmission unit 144b transmits the quantity information to the management device 150 at predetermined time intervals (for example, every 60 seconds).

== Configuration of management device 150 ==
The management device 150 will be described as follows with reference to FIGS. 6 and 7.

FIG. 6 is a diagram showing an example of the hardware configuration of the management device 150. As shown in FIG. 6, the management device 150 is configured to include the second communication device 151. Second communication device 151
Has an interface such as a wireless LAN adapter or a NIC for connecting to the network 170, and is connected to the network 170 via the network device 160.
The second communication device 151 communicates with the string monitoring device 140 via the multi-hop network.

As shown in FIG. 6, the hardware of the second communication device 151 includes a processor 1511, a memory 1512, a timing device 1513, and a communication circuit 1514. Since each component is the same as that of the first communication device 144, the description thereof will be omitted.

FIG. 7 is a diagram showing an example of the software configuration of the second communication device 151. As shown in FIG. 7, the software of the second communication device 151 can realize the functions of the multi-hop communication unit 151a and the determination device transmission unit 151b. These functions are, for example, the second communication device 151.
This is realized by the processor 1511 of the above reading and executing the program stored in the memory 1512. Note that these functions may be realized by hardware such as ASIC.

The multi-hop communication unit 151a is a function for communicating with the string monitoring device 140 via the multi-hop network. The multi-hop communication unit 151a includes, for example, a route control function, an access control function, a channel estimation / allocation function, an error control function, a flow control function, a congestion control function, a QoS management function, and the like for performing communication. The determination device transmission unit 151b is a function for communicating with the photovoltaic power generation failure determination device 10 via the network device 160.

== Configuration of photovoltaic power generation failure determination device 10 ==
The configuration of the photovoltaic power generation failure determination device 10 will be described as follows with reference to FIGS. 8 to 13.

The photovoltaic power generation failure determination device 10 is a string 130 in the photovoltaic power generation system 100.
It is a device that determines whether or not the string 130 has failed by utilizing the phenomenon that the various amounts of electricity output from the string 130 fluctuate at the time of failure. In the following, it is described that the photovoltaic power generation failure determination device 10 performs failure determination in string units composed of a plurality of solar cell panels 131 and 132, but the present invention is not limited to this. For example, the failure determination may be performed for each solar cell panel constituting the string 130, or for each junction box, current collector box, or power conditioner. In this case, the description of the string 130 in the following description is replaced with the solar cell panels 131, 132, the junction box 121, the current collector box 120, or the power conditioner 110, and is applied to the failure determination.

FIG. 8 is a diagram showing an example of the hardware configuration of the photovoltaic power generation failure determination device 10. FIG. 8
As shown in the above, the hardware of the photovoltaic power generation failure determination device 10 includes a processor 11, a memory 12, a storage device 13, an input device 14, an output device 15, and a third communication device 16. It is configured. The processor 11 is, for example, an MPU, a CPU, or the like. The memory 12 is, for example, a RAM, a ROM, an NVRAM, or the like. The storage device 13 is, for example, R.
AM, ROM, NVRAM, etc. The input device 14 is a user interface that receives operation input from the user, and is, for example, an operation input device (keyboard, mouse, touch panel, etc.), a voice input device (microphone, etc.), and the like. The output device 15 is a user interface that provides various information to the user, and is, for example, a display device (liquid crystal monitor or the like), an audio output device (speaker or the like), or the like. The third communication device 16 is an interface for connecting to the network 170, for example, a wireless LAN adapter and a NIC (Network Inte).
rface Card) and so on.

FIG. 9 is a diagram showing an example of the software configuration of the photovoltaic power generation failure determination device 10. Figure 9
As shown in the above, the software of the photovoltaic power generation failure determination device 10 includes an acquisition unit 10a, an extraction unit 10b, a first calculation unit 10c, a solar radiation stability determination unit 10d, a second calculation unit 10e, and a threshold value comparison unit. It has the functions of 10f and the failure determination unit 10g. These functions are realized, for example, by the processor 11 of the photovoltaic power generation failure determination device 10 reading and executing the program stored in the memory 12. In addition, these functions may be realized by hardware such as ASIC. Further, the processor 11 may be realized by reading and executing a program stored in an external storage medium.

Note that FIG. 9 shows that the photovoltaic power generation failure determination device 10 realizes each function with one information processing device (computer), but the present invention is not limited to this. For example, each of the above-mentioned functions may be distributed and realized by two or more information processing devices. In the following, as an example, each function will be realized by one information processing device.

The photovoltaic power generation failure determination device 10 stores various amount information input via the third communication device 16, various information calculated by each of the above-mentioned functions, and various information input from an external device (not shown). Has a function to record in.

Specifically, the storage device 13 includes a string arrangement management table 10h showing an example in which the string ID as shown in FIG. 10 and the physical address (for example, MAC address) of the string monitoring device 140 are associated with each other. An electrical quantity table 10i showing an example in which the string ID as shown in FIG. 11 and the quantity information of each string 130 are associated with each other, and the string ID as shown in FIG. 12, for example, from March 1 to March. FIG. 13 shows an extraction table 10j showing an example in which various quantity information indicating the maximum value or the minimum value of the electrical quantities extracted by the extraction unit 10b is associated with each time in a predetermined period up to 3 days. An average electric quantity table 10k showing an example in which a time ID indicating a time as shown and an average electric quantity are associated with each other is stored.

Hereinafter, each function of the photovoltaic power generation failure determination device 10 will be described in detail.

The acquisition unit 10a is a function of acquiring various quantity information indicating various electrical quantities output from the string 130. Further, when it is necessary to access a publicly available database such as the Japan Meteorological Agency database 200, it has a function of acquiring predetermined information from the database.

The extraction unit 10b is a string 13 at a predetermined time in a predetermined period.
It is a function to extract electric quantities showing a predetermined value from electric quantities output from 0. Here, the predetermined value is, for example, a maximum electric quantity value indicating a maximum value or a minimum electric quantity value indicating a minimum value. As an example, the extraction unit 10b is based on the electrical quantity table 10i shown in FIG. 11, for example, the maximum electrical quantity value for each string 130 from March 1st to March 3rd at 12:00. Or extract the minimum electrical quantity values. In the following, among the maximum electric quantity values, those related to current may be referred to as maximum current value, those related to voltage may be referred to as maximum voltage value, and those related to impedance may be referred to as maximum impedance value. Further, among the minimum electrical quantity values, those related to current may be indicated as the minimum current value, those related to voltage may be indicated as the minimum voltage value, and those related to impedance may be indicated as the minimum impedance value.

The first calculation unit 10c is a function of calculating the average electric amount indicating the average of the maximum electric amount value or the minimum electric amount value of the extracted electric amounts in each string 130. The average electric quantity includes, for example, an average current value indicating an average of current values, an average voltage value indicating an average of voltage values, or an average impedance value indicating an average of impedance values. The first calculation unit 1
In addition to the function of calculating the average electric quantity, 0c may have a function of calculating the median electrical quantity indicating the median value among the plurality of maximum electrical quantity values or the minimum electrical quantity values. In the following, it will be described that the first calculation unit 10c calculates the average electric quantity and realizes other functions by using the average electric quantity, but the central electric quantity is used instead of the average electrical quantity. It may be used to realize other functions.

The solar radiation stability determination unit 10d is a function of determining whether or not the average current value is larger than the solar radiation stable current value, which is a predetermined constant. The solar radiation stability determination unit 10d is a function for executing failure determination in a situation where the solar radiation is stable. The same value may be set for the solar radiation stable current value throughout the day, or a different value may be set for each predetermined time of the day.

Instead of determining whether or not the solar radiation is stable by the solar radiation stability determination unit 10d, the photovoltaic power generation failure determination device 10 acquires weather information from, for example, the Japan Meteorological Agency database (not shown).
You may extract the amount of electricity at a sunny time. Further, the sunny time is determined based on the solar radiation amount information at a predetermined time acquired from the solar radiation meter (not shown) provided in the vicinity of the photovoltaic power generation system 100, and the electric quantities of the sunny time are determined. May be extracted. This will
Since the processing by the solar radiation stability determination unit 10d can be reduced, the processing time can be reduced.

The second calculation unit 10e is the maximum electricity in the string 130 (hereinafter, referred to as “specific string 130”) to be determined for failure based on various information associated with the string ID or the time ID in a predetermined period. It is a function to calculate the amount deviation rate by dividing the various amount value or the minimum electric amount value by the average electric amount value.

The threshold value comparison unit 10f is a function of comparing the deviation rate of various quantities with a predetermined deviation threshold value.
The threshold value comparison unit 10f has a function of incrementing the failure determination time based on the comparison result between the deviation rate of various quantities and the deviation threshold value.

The failure determination unit 10g is a function of comparing the failure determination time with a predetermined failure threshold value and determining whether or not there is a failure based on the comparison result.

== First flow showing an example of failure determination of the photovoltaic power generation failure determination device 10 ==
The failure determination flow of the photovoltaic power generation failure determination device 10 will be described below with reference to FIG. FIG. 14 is a flow chart showing an example of a failure determination procedure of the photovoltaic power generation failure determination device 10. In the following description, when each function is the subject, the processor 11
Means that reads a program and realizes a predetermined function.

An example of the failure determination procedure of the photovoltaic power generation failure determination device 10 is to extract the maximum electric value and fail in order to utilize the phenomenon that the electric value of the string 130 decreases when the string 130 fails. This is the judgment procedure.

The photovoltaic power generation failure determination device 10 repeatedly executes the following processes S11 to S18 at predetermined time intervals from the present time (S10). In the following, as an example, the specific string 130 for identifying the failure is the 1-1-1 string 130, and the current time is 12:00 on March 4th.
Minutes and electric currents will be described as currents. In the following processing, a failure can be similarly determined by using various amounts of electricity as voltage or impedance, and therefore the description of voltage and impedance will be omitted.

First, the acquisition unit 10a acquires various quantity information indicating the electrical quantities output from the string 130, associates the quantity information with the string ID, and stores the quantity information in the storage device 13.

Next, the extraction unit 10b extracts the maximum current value indicating the largest value among the current values at a predetermined time in the past predetermined period (S11). Specifically, when the predetermined period in the past is set to "3 days", the extraction unit 10b is associated with, for example, 1-1-1 string 130 from the electrical quantity table 10i shown in FIG. "7" indicating the largest value (maximum current value) among the current values at a predetermined time from March 1st to March 3rd, for example, 12:00.
Is extracted. Similarly, the extraction unit 10b extracts the maximum current value for the strings 130 other than the 1-1-1 string 130 (1-1-2 strings 130 to). Extraction unit 10b
Stores the extracted maximum current value at a predetermined time in the storage device. The storage device stores the maximum current value in association with the string ID, for example, as shown in the extraction table 10j shown in FIG.

The processing of the extraction unit 10b described above will be described with reference to FIGS. 15 and 16 using a graph. First, plotting the current values of the 1-1-1 string 130 at each time from March to March 3 produces the first graph as shown in FIG. Then, the extraction unit 10b
Extracts and plots the maximum current value of the currents output from each of all the strings 130 at each time, and a second graph as shown in FIG. 16 is generated. That is, the extraction unit 10b
With the function of, a second graph obtained by extracting and plotting the maximum current value at each time in a predetermined period is obtained.

Next, the first calculation unit 10c is a string connected to the junction box 121 at a predetermined time (for example, 12:00) in the past predetermined period (for example, March 1st to March 3rd). Calculate the average current value indicating the average value of each maximum current value in 130 (S12).
.. For example, at the maximum current value at 12:00 associated with each of the string IDs shown in FIG. 12, the average current value indicating the average of the maximum current values of all the strings 130 is calculated. Specifically, the average current values are "7" and 1 of the maximum current values of the 1-1-1 string 130.
-1-2 Calculates the sum of the maximum current value of string 130 "7.2" and the maximum current value of other strings 130 (not shown), and divides the sum by the number of strings to be calculated. .. 1st
The calculation unit 10c associates the calculated average current value with the time ID and stores it in the storage device 13 as shown in the average electrical quantity table 10k shown in FIG.

Next, the solar radiation stability determination unit 10d determines whether or not the average current value at a predetermined time is equal to or greater than the solar radiation stable current value which is a predetermined constant (S13). Specifically, for example, 12
At 00:00, the solar radiation stability determination unit 10d acquires the average current value of "7.1" from the average electric quantity table 10k. Then, in the solar radiation stability determination unit 10d, the solar radiation stability current value is, for example, ".
When it is set to "4", it is determined that the average current value (7.1) is equal to or higher than the solar radiation stable current value (4). As a result, it is determined that the solar radiation is stable and the process is shifted to S14. (S13)
: YSE). On the other hand, when the average current value is, for example, "3", the solar radiation stability determination unit 10d determines that the average current value (3) is less than the solar radiation stable current value (4). As a result, it is determined that the solar radiation is not stable, and the process is repeated from S10 (S13: NO). By this process, the photovoltaic power generation failure determination device 10 can execute the failure determination in the situation where the solar radiation is stable.

Next, the second calculation unit 10e calculates the various quantity deviation rate by dividing the maximum current value in the specific string 130 by the average current value (S14). Specifically, for example, at 12:00, the second calculation unit 10e acquires "7", which is the maximum current value of the 1-1-1 string 130, from the extraction table 10j, and the average electrical quantity table 10k. The average current value "7.1" is obtained from. The second calculation unit 10e calculates the amount deviation rate as "99%" by converting the value obtained by dividing the maximum current value by the average current value as a percentage. By the processing of the second calculation unit 10e, the failure determination can be realized by relative comparison, so that the accuracy of the failure determination can be improved.

Next, the threshold value comparison unit 10f compares the calculated various quantity deviation rate with the predetermined deviation threshold value (S15). Specifically, the threshold comparison unit 10f has a deviation threshold of, for example, "90%".
When set to, since the quantity deviation rate is calculated as "99%" as described above, it is determined that the quantity deviation rate (99%) is equal to or higher than the deviation threshold value (90%). As a result, it is determined that the specific string 130 has not failed, and the process is repeated from S10 (S15: NO). On the other hand, when the deviation threshold is set to, for example, "90%", for example, when the quantity deviation rate is calculated as "80%" by the second calculation unit 10e, the quantity deviation rate (80%) is the deviation threshold. It is determined that it is less than (90%). As a result, it is determined that the specific string 130 may have failed, and the process shifts to S16 (S15: YES). When the quantity deviation rate is "80%", it indicates that the ratio of the maximum current value of the specific string 130 to the average current value of all the strings 130 is small. That is, it is shown that the current value of the specific string 130 is relatively reduced with respect to the current values of all the strings 130.

The failure determination unit 10g counts the number of times the threshold value comparison unit 10f determines that there is a possibility of failure (S16), and compares the determined number of times with a predetermined failure threshold value for comparison. Based on the result, it is determined whether or not there is a failure (S17). Specifically, when it is determined that the threshold value comparison unit 10f may have failed at 12:00, if the failure determination time is set to, for example, the initial value "1", the failure determination value is incremented to "1". 2 ”
To. Then, the failure determination unit 10g compares the incremented failure determination value (2) with the failure threshold value preset to, for example, “10”. In this case, since the failure determination value (2) is less than the failure threshold value (10), the failure determination unit 10g repeats the process from S11 (S17).
: NO). S11 to S16 are repeated until the failure determination value becomes equal to or higher than the failure threshold value. This process is for not determining a decrease in the amount of electricity in a short time due to a shadow or the like as a failure. S11
When the failure determination value becomes “10” as a result of repeating the processes of to S16, the failure determination unit 10
Since the failure determination value (10) is equal to or higher than the failure threshold value (10), it can be determined that g is not a temporary decrease in the amount of electricity due to shadows or the like, and it is determined that the specific string 130 has failed (S).
19).

In the failure determination unit 10g, when the threshold value comparison unit 10f determines that the deviation rate is larger than the deviation threshold value (S15: NO), or when the solar radiation stability determination unit 10d determines that the average current value is larger than the solar radiation stable current value. If it is determined that the value is also small (S13: NO), the failure determination value is reset (S).
18). As a result, since the situation in which the specific string 130 may have failed does not continue, it can be determined that the output of the specific string 130 is temporarily reduced due to a shadow or the like. That is, it is possible to eliminate the failure determination due to a temporary influence such as a shadow.

== Second flow showing another example of failure determination of the photovoltaic power generation failure determination device 10 ==
With reference to FIG. 17, another example of the failure determination flow of the photovoltaic power generation failure determination device 10 will be described as follows. FIG. 17 is a flow chart showing another example of the failure determination procedure of the photovoltaic power generation failure determination device 10.

Another example of the failure determination procedure of the photovoltaic power generation failure determination device 10 is a solar cell panel 132 in which the string monitoring device 140 is not installed when a failure occurs in the specific string 130.
In order to utilize the phenomenon that the voltage value and the impedance value detected by the string monitoring device 140 increase when (see FIG. 1) fails, the failure is determined by extracting the minimum electrical amount value in the voltage value or the impedance value. The procedure. Although the voltage value will be described below, the impedance value will be applied by replacing the voltage value with the impedance value because the same tendency is shown, and the description thereof will be omitted.

First, the extraction unit 10b extracts the minimum voltage value indicating the smallest value among the voltage values at a predetermined time in the past predetermined period (S21). The extraction method is S11 of the first flow.
Since it is the same as the above, a specific example is omitted.

The processing of the extraction unit 10b will be described in a graph format with reference to FIGS. 18 and 19. First, by plotting the voltage values at each time from March to March 3 on the 1-1-1 string 130, a third graph as shown in FIG. 18 can be generated. Then, when the extraction unit 10b extracts and plots the minimum voltage value among the voltages output from each of all the strings 130 at each time, a fourth graph as shown in FIG. 19 can be generated. That is, the fourth graph is
It is a graph which extracted and plotted the minimum of the voltage value at each time in the 3rd graph.

Next, the first calculation unit 10c receives each string connected to the junction box 121 at a predetermined time (for example, 12:00) in the past predetermined period (for example, March 1st to March 3rd). The average current value indicating the average value of each maximum current value in 130 and the average minimum voltage value indicating the average of each minimum voltage value in each string 130 connected to the junction box 121 are calculated (S22). ). Since the calculation method is the same as S12 in the first flow, a specific example will be omitted.

Next, the solar radiation stability determination unit 10d determines whether or not the average current value at a predetermined time is equal to or greater than the solar radiation stable current value which is a predetermined constant (S23). The determination method is S1 of the first flow.
Since it is the same as No. 3, the description thereof will be omitted.

Next, the second calculation unit 10e divides the minimum voltage value in the specific string 130 by the average minimum voltage value to calculate the amount deviation rate (S24). Since the calculation method is the same as the one in which the maximum current value in S14 of the first flow is replaced with the minimum voltage value and the average current value is replaced with the average minimum voltage value, a specific example is omitted.

Next, the threshold value comparison unit 10f compares the calculated various quantity deviation rate with the predetermined deviation threshold value (S25). Specifically, the threshold comparison unit 10f has a deviation threshold of, for example, "110%".
When set to, for example, when the amount deviation rate is calculated to be "105%", it is determined that the amount deviation rate (105%) is equal to or less than the deviation threshold value (110%). , It is determined that the specific string 130 has not failed, and the process is repeated from S20 (S25: NO).
). On the other hand, when the deviation threshold is set to, for example, "110%", for example, the amount deviation rate is ".
When it is calculated to be "111%", it is determined that the amount deviation rate (111%) is larger than the deviation threshold value (110%). As a result, it is determined that the specific string 130 may be out of order. Then, the process is shifted to S26 (S25: YES). For example, the deviation rate of various quantities is "111%".
In the case of ", the ratio of the minimum voltage value of the specific string 130 to the average minimum voltage value of all strings 130 is large. That is, the minimum voltage value of the specific string 130 is each of the total strings 130. It is shown that it increases relative to the minimum voltage value.

Next, the failure determination unit 10g counts the number of times that the threshold value comparison unit 10f determines that there is a possibility of failure (S26), and compares the determined number of times with a predetermined failure threshold value. , It is determined whether or not there is a failure based on the comparison result (S27). Since the determination method is the same as S26 and S27 in the first flow, the description thereof will be omitted.

In the failure determination unit 10g, when the threshold value comparison unit 10f determines that the deviation rate is equal to or less than the deviation threshold value (S25: NO), or when the solar radiation stability determination unit 10d determines that the average current value is smaller than the solar radiation stable current value. If it is determined (S23: NO), the failure determination value is reset (S28).

=== Summary ===
As described above, the photovoltaic power generation failure determination device 10 according to the present embodiment has the acquisition unit 10a for acquiring various quantity information indicating various amounts of electricity output from each of the plurality of strings 130, and the various quantity information. Based on, at a given time in a given period in the past, a plurality of strings 1
Among the electric quantities output from the predetermined specific string 130 out of 30, the electric quantities (maximum value or minimum value) indicating a predetermined value are extracted, and the electricity output from each of the plurality of strings 130. Of the various quantities, the extraction unit 10b that extracts the electrical quantities (maximum value or minimum value) indicating a predetermined value, and the plurality of electrical quantities (maximum value or minimum value) output from each of the plurality of strings 130. First calculation unit 10c that calculates the amount of electricity (average amount of electricity or central amount of electricity) based on, and the amount of electricity with respect to the amount of electricity (average amount of electricity or central electricity amount) at a predetermined time. The predetermined situation continues based on the comparison result of the threshold comparison unit 10f for comparing the deviation rate of various quantities (maximum value or the minimum value) and the deviation threshold, and the threshold comparison unit 10f in the past predetermined period. It is provided with a failure determination unit 10g that determines whether or not the time exceeds the failure threshold and determines the state of the specific string 130 based on the determination result.
According to the present embodiment, it is possible to appropriately determine a failure without determining a temporary change due to a shadow or the like as a failure. In addition, it is possible to appropriately determine a failure state in which the output is stably reduced due to deterioration.

Further, the electric powers in the photovoltaic power generation failure determination device 10 according to the present embodiment are any of current, voltage, and impedance, and the extraction unit 10b extracts the maximum value of the electric powers. Further, the failure determination unit 10g determines the duration of the situation in which the deviation rate is equal to or less than the deviation threshold value, and when the continuation time exceeds the failure threshold value, the specific string 13
It is determined that 0 is out of order. According to the present embodiment, there is a possibility that the specific string 130 has failed when the electric quantity values of the specific string 130 are relatively small with respect to the electric quantity values of all the strings 130. It can be determined that there is. That is, the specific string 13
Since the failure is determined by relative comparison of the electric quantity values using the characteristic that the electric quantity values decrease when 0 fails, the failure determination accuracy can be further improved.

Further, the electric powers in the photovoltaic power generation failure determination device 10 according to the present embodiment are either voltage or impedance, and the extraction unit 10b extracts the minimum value of the electric powers.
Further, the failure determination unit 10g determines the duration of the situation in which the various quantity deviation rate is larger than the deviation threshold value, and when the continuation time exceeds the failure threshold value, the specific string 13
It is determined that 0 is out of order. According to the present embodiment, when the electric quantity values of the specific string 130 increase relative to the electric quantity values of all the strings 130, it is possible that the specific string 130 has failed. It can be determined that there is. That is, when the solar cell panel 132 in which the string monitoring device 140 is not installed fails, the string monitoring device 1
Since the failure is determined by making a relative comparison between the voltage value and the impedance value using the characteristic that the voltage value and the impedance value detected by the 40 increase, the failure determination accuracy can be further improved.

It should be noted that the above embodiment is for facilitating the understanding of the present invention, and is not for limiting the interpretation of the present invention. The present invention can be modified and improved without departing from the spirit thereof, and the present invention also includes an equivalent thereof.

10 Photovoltaic power generation failure determination device 10a Acquisition unit 10b Extraction unit 10c First calculation unit 10e Second calculation unit 10f Threshold comparison unit 10g Failure determination unit

Claims (10)

An acquisition unit that acquires various amount information indicating the amount of electricity output from each of multiple solar cells,
A first indicating a predetermined value among the electric quantities output from a predetermined specific solar cell among the plurality of solar cells at a predetermined time in a predetermined period in the past based on the various quantity information. An extraction unit that extracts various amounts of electricity and extracts a second amount of electricity indicating a predetermined value among the various amounts of electricity output from each of the plurality of solar cells.
A calculation unit that calculates the third electrical quantity based on the plurality of second electrical quantities,
A comparison unit that compares the ratio of the first electrical quantities to the third electrical quantities and the first threshold value at the predetermined time.
In the predetermined period in the past, it is determined whether or not the time for which the predetermined situation continues exceeds the second threshold value based on the comparison result compared by the comparison unit, and the specific solar cell is determined based on the determination result. Judgment unit that determines the state of
A photovoltaic power generation failure determination device characterized by being equipped with. The electrical quantities are either current, voltage or impedance.
The photovoltaic power generation failure determination device according to claim 1, wherein the extraction unit extracts the maximum value of the electric quantities as the first electric quantity and the second electric quantity. The determination unit determines the duration of the situation in which the ratio is equal to or less than the first threshold value, and when the continuation time exceeds the second threshold value, the specific solar cell is out of order. The solar power generation failure determination device according to claim 2, wherein the determination is made. The electrical quantities are either voltage or impedance and
The photovoltaic power generation failure determination device according to claim 1, wherein the extraction unit extracts the minimum value of the electric quantities as the first electric quantity and the second electric quantity. The determination unit determines the duration of the situation in which the ratio becomes larger than the first threshold value, and when the continuation time becomes equal to or greater than the second threshold value, the specific solar cell fails. The solar power generation failure determination device according to claim 4, wherein the solar cell is determined to be present. The photovoltaic power generation failure determination device according to claim 1 to 5, wherein the calculation unit calculates an average value of a plurality of the second electric quantities as the third electric quantities. The failure determination device according to claim 1 to 5, wherein the calculation unit calculates the median value of a plurality of the second electric quantities as the third electric quantities. On the computer
An acquisition function that acquires various amount information indicating the amount of electricity output from each of multiple solar cells,
A first indicating a predetermined value among the electric quantities output from a predetermined specific solar cell among the plurality of solar cells at a predetermined time in a predetermined period in the past based on the various quantity information. An extraction function that extracts various amounts of electricity and extracts a second amount of electricity that indicates a predetermined value from the various amounts of electricity output from each of the plurality of solar cells.
A calculation function that calculates the third electrical quantity based on the plurality of second electrical quantities, and
A comparison function for comparing the ratio of the first electric quantity to the third electric quantity and the first threshold value at the predetermined time.
In the past predetermined period, it is determined whether or not the duration of the predetermined situation exceeds the second threshold value based on the comparison result compared by the comparison function, and the specific solar cell is determined based on the determination result. Judgment function to judge the state of
A program to realize. An acquisition function that acquires various amount information indicating the amount of electricity output from each of multiple solar cells to the computer,
A first indicating a predetermined value among the electric quantities output from a predetermined specific solar cell among the plurality of solar cells at a predetermined time in a predetermined period in the past based on the various quantity information. An extraction function that extracts various amounts of electricity and extracts a second amount of electricity that indicates a predetermined value from the various amounts of electricity output from each of the plurality of solar cells.
A calculation function that calculates the third electrical quantity based on the plurality of second electrical quantities, and
A comparison function for comparing the ratio of the first electric quantity to the third electric quantity and the first threshold value at the predetermined time.
In the past predetermined period, it is determined whether or not the duration of the predetermined situation exceeds the second threshold value based on the comparison result compared by the comparison function, and the specific solar cell is determined based on the determination result. Judgment function to judge the state of
A computer-readable recording medium that records programs to achieve this. The computer
The acquisition step to acquire the quantity information indicating the quantity of electricity output from each of the plurality of solar cells,
A first indicating a predetermined value among the electric quantities output from a predetermined specific solar cell among the plurality of solar cells at a predetermined time in a predetermined period in the past based on the various quantity information. An extraction step of extracting various amounts of electricity and extracting a second amount of electricity indicating a predetermined value from the various amounts of electricity output from each of the plurality of solar cells.
A calculation step of calculating the third electric quantity based on the plurality of the second electric quantities, and
A comparison step of comparing the ratio of the first electric quantity to the third electric quantity and the first threshold value at the predetermined time.
In the predetermined period in the past, it is determined whether or not the duration of the predetermined situation exceeds the second threshold value based on the comparison result compared in the comparison step, and the specific solar cell is determined based on the determined result. Judgment step to judge the state of
Solar power generation failure judgment method to realize.

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