JPWO2019187525A1 - Judgment device, photovoltaic power generation system and judgment method - Google Patents

Abstract

The determination device is a determination device used in a photovoltaic power generation system including a plurality of power generation units including a solar cell panel, and acquires and acquires a plurality of measurement information indicating the measurement results of the output currents of the plurality of power generation units. A unit, a detection unit that detects the occurrence of a state due to overloading of the photovoltaic power generation system, and the power generation corresponding to the output current based on the fluctuation of the output current when the state occurs. It is provided with a determination unit for determining an abnormality of the unit.

Description

The present invention relates to a determination device, a photovoltaic power generation system, and a determination method.
This application claims priority on the basis of Japanese application Japanese Patent Application No. 2018-58753 filed on March 26, 2018, and incorporates all of its disclosures herein.

Japanese Unexamined Patent Publication No. 2012-205878 (Patent Document 1) discloses the following monitoring system for photovoltaic power generation. That is, the photovoltaic power generation monitoring system is a photovoltaic power generation monitoring system that monitors the power generation status of the solar panel with respect to the photovoltaic power generation system that aggregates the outputs from the plurality of solar panel and sends them to the power conversion device. Therefore, a measuring device that is provided at a place where output electric circuits from the plurality of solar panel panels are integrated and measures the amount of power generated by each solar panel, and a measuring device that is connected to the measuring device and has a power generation amount by the measuring device. The solar panel via a lower communication device having a function of transmitting measurement data, an upper communication device having a function of receiving the measurement data transmitted from the lower communication device, and the upper communication device. It is provided with a management device having a function of collecting the measurement data for each. The management device determines the presence or absence of an abnormality based on the difference in the amount of power generation at the same time point for each of the solar cell panels, or the maximum value or the total amount of the amount of power generation for each of the solar cell panels for a predetermined period. The presence or absence of an abnormality is determined based on the value.

Japanese Unexamined Patent Publication No. 2012-205878

(1) The determination device of the present disclosure is a determination device used in a photovoltaic power generation system including a plurality of power generation units including a solar cell panel, and a plurality of determination devices showing measurement results of output currents of the plurality of power generation units. The output is based on an acquisition unit that acquires measurement information, a detection unit that detects the occurrence of a state due to overloading of the photovoltaic power generation system, and a fluctuation in the output current when the state occurs. It is provided with a determination unit for determining an abnormality of the power generation unit corresponding to the current.

(4) The photovoltaic power generation system of the present disclosure is a photovoltaic power generation system including a plurality of power generation units including a solar cell panel and a determination device, and the determination device is the output current of the plurality of power generation units. A plurality of measurement information indicating each measurement result is acquired, the occurrence of a state due to overloading of the photovoltaic power generation system is detected, and the output current fluctuates when the state occurs. The abnormality of the power generation unit corresponding to the output current is determined.

(5) The determination method of the present disclosure is a determination method in a determination device used in a photovoltaic power generation system including a plurality of power generation units including a solar cell panel, and is in a state caused by overloading of the photovoltaic power generation system. It includes a step of detecting the occurrence and a step of determining an abnormality of the power generation unit corresponding to the output current based on fluctuations in output currents of the plurality of power generation units when the state occurs.

One aspect of the present disclosure can be realized not only as a determination device provided with such a characteristic processing unit, but also as a program for causing a computer to execute such a characteristic processing step. Further, one aspect of the present disclosure may be realized as a semiconductor integrated circuit that realizes a part or all of the determination device, or may be realized as a system including the determination device.

Further, one aspect of the present disclosure can be realized not only as a photovoltaic power generation system provided with such a characteristic processing unit, but also as a determination method in which the characteristic processing is a step, or such a step. Can be realized as a program for causing a computer to execute. Further, one aspect of the present disclosure can be realized as a semiconductor integrated circuit that realizes a part or all of a photovoltaic power generation system.

FIG. 1 is a diagram showing a configuration of a photovoltaic power generation system according to an embodiment of the present invention. FIG. 2 is a diagram showing a configuration of a PCS unit according to an embodiment of the present invention. FIG. 3 is a diagram showing a configuration of a current collector unit according to an embodiment of the present invention. FIG. 4 is a diagram showing a configuration of a solar cell unit according to an embodiment of the present invention. FIG. 5 is a diagram showing a configuration of a monitoring system according to an embodiment of the present invention. FIG. 6 is a diagram showing a configuration of a monitoring device in the monitoring system according to the embodiment of the present invention. FIG. 7 is a diagram showing a configuration of a determination device in the monitoring system according to the embodiment of the present invention. FIG. 8 is a diagram showing an example of monitoring information held by the determination device in the monitoring system according to the embodiment of the present invention. FIG. 9 is a diagram showing the generated power of the power generation unit in the overloaded state. FIG. 10 is a diagram showing the relationship between the output current and the output voltage of the power generation unit in the power generation state determination system according to the embodiment of the present invention. FIG. 11 is a diagram showing an example of the output currents of the normal power generation unit and the abnormal power generation unit in the overloaded state. FIG. 12 is a flowchart defining an operation procedure when the determination device according to the embodiment of the present invention determines an abnormality related to the power generation unit.

In recent years, techniques for monitoring a photovoltaic power generation system and discriminating abnormalities have been developed.

[Issues to be solved by this disclosure]
A technique capable of improving the abnormality determination of the photovoltaic power generation system beyond the technique described in Patent Document 1 is desired.

The present disclosure has been made to solve the above-mentioned problems, and an object thereof is to provide a determination device, a photovoltaic power generation system, and a determination method capable of improving the abnormality determination of the photovoltaic power generation system. is there.

[Effect of the present disclosure]
According to the present disclosure, it is possible to improve the abnormality determination of the photovoltaic power generation system.

[Explanation of Embodiments of the Invention]
First, the contents of the embodiments of the present invention will be listed and described.

(1) The determination device according to the embodiment of the present invention is a determination device used in a photovoltaic power generation system including a plurality of power generation units including a solar cell panel, and is a measurement result of output currents of the plurality of power generation units. The acquisition unit that acquires a plurality of measurement information indicating each of the above, the detection unit that detects the occurrence of a state due to the overloading of the photovoltaic power generation system, and the fluctuation of the output current when the state occurs. Based on this, a determination unit for determining an abnormality of the power generation unit corresponding to the output current is provided.

With such a configuration, in a photovoltaic power generation system, it is possible to focus on a phenomenon that occurs in a state caused by overloading and to satisfactorily detect a power generation unit suspected of having an abnormality. Therefore, it is possible to improve the abnormality determination of the photovoltaic power generation system.

(2) Preferably, the detection unit determines that the state has occurred when the total power generation based on the output current of each power generation unit or the total output current satisfies a predetermined condition.

With such a configuration, in the photovoltaic power generation system, a state caused by overloading occurs using the measurement results of each power generation unit without acquiring information on whether or not the solar power generation system is overloaded. Can be detected.

(3) Preferably, the output line from each power generation unit is electrically connected to the power conversion device, and the detection unit acquires information indicating the occurrence of the state from the power conversion device.

With such a configuration, it is possible to more reliably detect the occurrence of a state due to overloading in the photovoltaic power generation system.

(4) The photovoltaic power generation system according to the embodiment of the present invention is a photovoltaic power generation system including a plurality of power generation units including a solar cell panel and a determination device, and the determination device is the plurality of power generation units. A plurality of measurement information indicating the measurement result of the output current of the unit is acquired, the occurrence of a state due to overloading of the photovoltaic power generation system is detected, and the fluctuation of the output current when the state occurs. Based on the above, the abnormality of the power generation unit corresponding to the output current is determined.

With such a configuration, in a photovoltaic power generation system, it is possible to focus on a phenomenon that occurs in a state caused by overloading and to satisfactorily detect a power generation unit suspected of having an abnormality. Therefore, it is possible to improve the abnormality determination of the photovoltaic power generation system.

(5) The determination method according to the embodiment of the present invention is a determination method in a determination device used in a photovoltaic power generation system including a plurality of power generation units including a solar cell panel, and is an overload of the photovoltaic power generation system. A step of detecting the occurrence of a state caused by the above, and a step of determining an abnormality of the power generation unit corresponding to the output current based on fluctuations in output currents of the plurality of power generation units when the state occurs. And include.

With such a configuration, in a photovoltaic power generation system, it is possible to focus on a phenomenon that occurs in a state caused by overloading and to satisfactorily detect a power generation unit suspected of having an abnormality. Therefore, it is possible to improve the abnormality determination of the photovoltaic power generation system.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals, and the description thereof will not be repeated. In addition, at least a part of the embodiments described below may be arbitrarily combined.

[Solar power generation system configuration]
FIG. 1 is a diagram showing a configuration of a photovoltaic power generation system according to an embodiment of the present invention.

With reference to FIG. 1, the photovoltaic power generation system 401 includes four PCS (Power Conditioning Subsystem) units 80 and a cubicle 6. The cubicle 6 includes a copper bar 73.

Although four PCS units 80 are typically shown in FIG. 1, a large number or a small number of PCS units 80 may be provided.

FIG. 2 is a diagram showing a configuration of a PCS unit according to an embodiment of the present invention.

With reference to FIG. 2, the PCS unit 80 includes four current collector units 60 and a PCS (power conversion device) 8. The PCS 8 includes a copper bar 7 and a power conversion unit 9.

Although the four current collecting units 60 are typically shown in FIG. 2, a large number or a small number of current collecting units 60 may be provided.

FIG. 3 is a diagram showing a configuration of a current collector unit according to an embodiment of the present invention.

With reference to FIG. 3, the current collector unit 60 includes four solar cell units 74 and a current collector box 71. The current collector box 71 has a copper bar 72.

Although the four solar cell units 74 are typically shown in FIG. 3, a larger number or a smaller number of solar cell units 74 may be provided.

FIG. 4 is a diagram showing a configuration of a solar cell unit according to an embodiment of the present invention.

With reference to FIG. 4, the solar cell unit 74 includes four power generation units 78 and a junction box 76. The power generation unit 78 has a solar cell panel. The junction box 76 has a copper bar 77.

Although the four power generation units 78 are typically shown in FIG. 4, a large number or a small number of power generation units 78 may be provided.

In this example, the power generation unit 78 is a string in which four solar cell panels 79A, 79B, 79C, and 79D are connected in series. Hereinafter, each of the solar cell panels 79A, 79B, 79C, and 79D will also be referred to as a solar cell panel 79.

Although four solar cell panels 79 are typically shown in FIG. 4, a larger number or a smaller number of solar cell panels 79 may be provided.

In the photovoltaic power generation system 401, the output lines and the aggregation lines, that is, the power lines from the plurality of power generation units 78 are electrically connected to the cubicle 6, respectively.

More specifically, the output line 1 of the power generation unit 78 has a first end connected to the power generation unit 78 and a second end connected to the copper bar 77. Each output line 1 is aggregated into the aggregation line 5 via the copper bar 77. The copper bar 77 is provided inside, for example, the junction box 76.

When the power generation unit 78 receives sunlight, it converts the energy of the received sunlight into DC power and outputs the converted DC power to the output line 1.

With reference to FIGS. 3 and 4, the aggregation line 5 has a first end connected to the copper bar 77 in the corresponding solar cell unit 74 and a second end connected to the copper bar 72. Each aggregation line 5 is aggregated into the aggregation line 2 via the copper bar 72. The copper bar 72 is provided inside, for example, the current collector box 71.

With reference to FIGS. 1 to 4, in the photovoltaic power generation system 401, as described above, each output line 1 from the plurality of power generation units 78 is aggregated in the aggregation line 5, and each aggregation line 5 is aggregated in the aggregation line 2. Then, each aggregation line 2 is aggregated into the aggregation line 4, and each aggregation line 4 is electrically connected to the cubicle 6.

More specifically, each aggregation line 2 has a first end connected to a copper bar 72 in the corresponding current collecting unit 60 and a second end connected to the copper bar 7. In the PCS 8, the internal line 3 has a first end connected to the copper bar 7 and a second end connected to the power converter 9.

In the PCS8, for example, the power conversion unit 9 transmits the DC power generated by each power generation unit 78 via the output line 1, the copper bar 77, the aggregation line 5, the copper bar 72, the aggregation line 2, the copper bar 7, and the internal line 3. When it is received at, the received DC power is converted into AC power and output to the aggregation line 4.

The aggregation line 4 has a first end connected to the power conversion unit 9 and a second end connected to the copper bar 73.

In the cubicle 6, the AC power output from the power conversion unit 9 in each PCS 8 to each aggregation line 4 is output to the system via the copper bar 73.

[Configuration of monitoring system 301]
FIG. 5 is a diagram showing a configuration of a monitoring system according to an embodiment of the present invention.

With reference to FIG. 5, the photovoltaic power generation system 401 includes a monitoring system 301. The monitoring system 301 includes a determination device 101, a plurality of monitoring devices 111, and a collecting device 151.

Although FIG. 5 typically shows four monitoring devices 111 provided corresponding to one current collecting unit 60, a larger number or a smaller number of monitoring devices 111 may be provided. Further, although the monitoring system 301 includes one collecting device 151, a plurality of collecting devices 151 may be provided.

In the monitoring system 301, the information of the sensor in the monitoring device 111, which is a slave unit, is transmitted to the collecting device 151 periodically or irregularly.

The monitoring device 111 is provided in, for example, the current collecting unit 60. More specifically, four monitoring devices 111 are provided corresponding to each of the four solar cell units 74. Each monitoring device 111 is electrically connected to, for example, the corresponding output line 1 and aggregation line 5.

The monitoring device 111 measures the current of each output line 1 in the corresponding solar cell unit 74 by a sensor. Further, the monitoring device 111 measures the voltage of each output line 1 in the corresponding solar cell unit 74 by a sensor.

The collection device 151 is provided, for example, in the vicinity of the PCS 8. More specifically, the collecting device 151 is provided corresponding to the PCS 8 and is electrically connected to the copper bar 7 via the signal line 46.

The monitoring device 111 and the collecting device 151 transmit and receive information by performing power line communication (PLC) via the aggregation lines 2 and 5.

More specifically, each monitoring device 111 transmits monitoring information indicating the current and voltage measurement results of the corresponding output lines. The collection device 151 collects the measurement results of each monitoring device 111.

[Configuration of monitoring device 111]
FIG. 6 is a diagram showing a configuration of a monitoring device in the monitoring system according to the embodiment of the present invention. In FIG. 6, the output line 1, the aggregation line 5 and the copper bar 77 are shown in more detail.

With reference to FIG. 6, the output line 1 includes a plus side output line 1p and a minus side output line 1n. The aggregation line 5 includes a plus-side aggregation line 5p and a minus-side aggregation line 5n. The copper bar 77 includes a positive side copper bar 77p and a negative side copper bar 77n.

Although not shown, the copper bar 72 in the current collector box 71 shown in FIG. 3 includes a plus side copper bar 72p and a minus side copper bar 72n corresponding to the plus side aggregation line 5p and the minus side aggregation line 5n, respectively.

The positive output line 1p has a first end connected to the corresponding power generation unit 78 and a second end connected to the positive copper bar 77p. The negative side output line 1n has a first end connected to the corresponding power generation unit 78 and a second end connected to the negative side copper bar 77n.

The positive-side aggregation line 5p has a first end connected to the positive-side copper bar 77p and a second end connected to the positive-side copper bar 72p in the current collector box 71. The minus side aggregation line 5n has a first end connected to the minus side copper bar 77n and a second end connected to the minus side copper bar 72n in the current collector box 71.

The monitoring device 111 includes a detection processing unit 11, four current sensors 16, a voltage sensor 17, and a communication unit 14. The monitoring device 111 may further include a large number or a small number of current sensors 16 depending on the number of output lines 1.

The monitoring device 111 is provided, for example, in the vicinity of the power generation unit 78. Specifically, the monitoring device 111 is provided inside, for example, a junction box 76 provided with a copper bar 77 to which the output line 1 to be measured is connected. The monitoring device 111 may be provided outside the junction box 76.

The monitoring device 111 is electrically connected to, for example, the plus side aggregation line 5p and the minus side aggregation line 5n via the plus side power supply line 26p and the minus side power supply line 26n, respectively. Hereinafter, each of the positive power supply line 26p and the negative power supply line 26n is also referred to as a power supply line 26.

Each monitoring device 111 transmits monitoring information indicating the measurement result regarding the corresponding power generation unit 78 via the power line connected to itself and the collecting device 151.

Specifically, the communication unit 14 in the monitoring device 111 can perform power line communication via the aggregation line with the collecting device 151 that collects the measurement results of the plurality of monitoring devices 111. More specifically, the communication unit 14 can send and receive information via the aggregation lines 2 and 5. Specifically, the communication unit 14 performs power line communication with the collection device 151 via the power supply line 26 and the aggregation lines 2 and 5.

The detection processing unit 11 is set to, for example, create monitoring information indicating the current and voltage measurement results of the corresponding output line 1 at predetermined time intervals.

The current sensor 16 measures the current of the output line 1. More specifically, the current sensor 16 is, for example, a Hall element type current probe. The current sensor 16 measures the current flowing through the corresponding negative output line 1n using the electric power received from the power supply circuit (not shown) of the monitoring device 111, and outputs a signal indicating the measurement result to the detection processing unit 11. The current sensor 16 may measure the current flowing through the positive output line 1p.

The voltage sensor 17 measures the voltage of the output line 1. More specifically, the voltage sensor 17 measures the voltage between the positive side copper bar 77p and the negative side copper bar 77n, and outputs a signal indicating the measurement result to the detection processing unit 11.

The detection processing unit 11 converts, for example, a signal that has undergone signal processing such as averaging and filtering for each measurement signal received from each current sensor 16 and voltage sensor 17 into a digital signal at predetermined time intervals.

The detection processing unit 11 includes a measured value indicated by each of the created digital signals, an ID of the corresponding current sensor 16 (hereinafter, also referred to as a current sensor ID), and an ID of the voltage sensor 17 (hereinafter, also referred to as a voltage sensor ID). , And the ID of its own monitoring device 111 (hereinafter, also referred to as a monitoring device ID).

The detection processing unit 11 creates a monitoring information packet in which the source ID is its own monitoring device ID, the destination ID is the ID of the collecting device 151, and the data portion is monitoring information. Then, the detection processing unit 11 outputs the created monitoring information packet to the communication unit 14. The detection processing unit 11 may include the sequence number in the monitoring information packet.

The communication unit 14 transmits the monitoring information packet received from the detection processing unit 11 to the collection device 151.

With reference to FIG. 5 again, the collecting device 151 can transmit and receive information via the aggregation lines 2 and 5. Specifically, the collecting device 151 performs power line communication with the monitoring device 111 via the signal line 46 and the aggregation lines 2 and 5, and receives the monitoring information packet from the plurality of monitoring devices 111.

The collecting device 151 has a counter and a storage unit, and when it receives a monitoring information packet from the monitoring device 111, it acquires monitoring information from the received monitoring information packet and also acquires a count value in the counter as a reception time. Then, after including the reception time in the monitoring information, the collecting device 151 stores the monitoring information in a storage unit (not shown).

More specifically, the counter resets the count value at midnight of every day, and increments the count value every time the same time as the measurement cycle of the monitoring device 111 elapses. In this case, when the collecting device 151 receives a plurality of monitoring information packets from each of the plurality of monitoring devices 111 between the timing of incrementing the count value and the elapse of the above time, the collecting device 151 acquires from each of the plurality of monitoring information packets. Include the same current count value as the reception time in the monitored monitoring information.

[Configuration and operation of judgment device]
FIG. 7 is a diagram showing a configuration of a determination device in the monitoring system according to the embodiment of the present invention.

With reference to FIG. 7, the determination device 101 includes a determination unit 81, a communication processing unit 84, a storage unit 85, an acquisition unit 86, and a detection unit 87.

In the storage unit 85 of the determination device 101, for example, the ID of the monitoring device 111 to be managed, that is, the monitoring device ID is registered. Further, in the storage unit 85, the correspondence relationship R1 between the monitoring device ID and the ID of each sensor included in the monitoring device 111 having the monitoring device ID, that is, the current sensor ID and the voltage sensor ID is registered.

The determination device 101 is, for example, a server, periodically acquires monitoring information from the collecting device 151, and processes the acquired monitoring information. The determination device 101 may be built in, for example, the collection device 151.

More specifically, the communication processing unit 84 in the determination device 101 transmits / receives information to / from other devices such as the collection device 151 via the network.

The communication processing unit 84 performs monitoring information collection processing at a designated daily processing timing, for example, at midnight every day. If the determination device 101 is built in the collection device 151, monitoring information can be easily collected at shorter intervals.

More specifically, when the daily processing timing arrives, the communication processing unit 84 refers to each monitoring device ID registered in the storage unit 85, corresponds to each referenced monitoring device ID, and has a daily processing timing of 24 hours. A monitoring information request for requesting monitoring information including a reception time belonging to the processing day from the front to the processing timing (hereinafter, also referred to as a processing day) is transmitted to the collection device 151.

When the collecting device 151 receives the monitoring information request from the determination device 101, the collecting device 151 transmits one or a plurality of monitoring information satisfying the contents of the monitoring information request to the determination device 101 according to the received monitoring information request.

FIG. 8 is a diagram showing an example of monitoring information held by the determination device in the monitoring system according to the embodiment of the present invention.

With reference to FIG. 8, the monitoring information includes a monitoring device ID, a current sensor ID of each current sensor 16 in the monitoring device 111, a current value measured by each current sensor 16, and a voltage sensor ID of the voltage sensor 17. And the voltage value which is the measured value of the voltage sensor 17, and the reception time. The reception time is the time when the collection device 151 receives the monitoring information transmitted from the monitoring device 111.

When the communication processing unit 84 receives one or more monitoring information from the collecting device 151 as a response to the monitoring information request, the communication processing unit 84 stores each received monitoring information in the storage unit 85 and outputs a processing completion notification to the detection unit 87. ..

The detection unit 87 detects the occurrence of a state (hereinafter, also referred to as an overload state) caused by the overload of the photovoltaic power generation system 401.

In the photovoltaic power generation system 401, providing a number of solar panels capable of generating electric power exceeding the power conversion capacity of the PCS 8 is referred to as overloading.

Further, in the photovoltaic power generation system 401, the overloaded state is a state in which the generated power of each power generation unit 78 is limited to the power conversion capacity of the PCS 8.

FIG. 9 is a diagram showing the generated power of the power generation unit in the overloaded state. In FIG. 9, the horizontal axis represents time and the vertical axis represents generated power.

With reference to FIG. 9, in the photovoltaic power generation system 401, an overloaded state occurs in the daytime, and the generated power of the power generation unit 78 is limited.

For example, the detection unit 87 determines that an overloaded state has occurred when the total of the measurement results indicated by the monitoring information of each power generation unit 78 satisfies a predetermined condition.

More specifically, when the detection unit 87 receives the processing completion notification from the communication processing unit 84, the detection unit 87 refers to the correspondence relationship R1 and measures the current sensor 16 included in the monitoring information of each monitoring device 111 from the storage unit 85. The current value, which is a value, and the voltage value, which is a measured value of the corresponding voltage sensor 17, are acquired.

Then, the detection unit 87 calculates the generated power of each power generation unit 78 at the reception time included in the monitoring information by multiplying the current value and the voltage value in a plurality of sets of the acquired current value and voltage value.

When the total value of the generated powers at the same received time calculated is, for example, a predetermined threshold Th1 or more, the detection unit 87 determines that the overloaded state has occurred at the received time.

The threshold value Th1 is determined, for example, based on the generated power of the power generation unit 78 predicted from the numerical value of the pyranometer, or is determined based on the rated capacity of the power generation unit 78.

The detection unit 87 determines the overload period from the occurrence of the overload state to the end of the overload state based on the reception time when the overload state has occurred, and acquires information indicating the determined overload period. Output to 86.

In addition, instead of confirming whether or not the total generated power of each power generation unit 78 satisfies the predetermined condition, the detection unit 87 confirms whether or not the total output current of each power generation unit 78 satisfies the predetermined condition. It may be a configuration. For example, when the total value of the output currents of the power generation units 78 at the same reception time is the threshold value Th3 or more, the detection unit 87 determines that the overloaded state has occurred at the reception time.

As another example, the detection unit 87 acquires information indicating the occurrence of an overloaded state from the PCS 8.

More specifically, the detection unit 87 receives, for example, information indicating the overload period from the PCS 8 via the signal line 46, the collection device 151, and the communication processing unit 84, and outputs the received information to the acquisition unit 86. ..

The acquisition unit 86 acquires measurement information indicating the measurement results of the output currents of the plurality of power generation units 78.

More specifically, for example, the acquisition unit 86 receives the information indicating the overload period, refers to the correspondence relationship R1 registered in the storage unit 85, and refers to each of the overload period and the time immediately before the overload period. The monitoring information of each monitoring device 111 including the measured value of the current sensor 16 is acquired from the storage unit 85 and output to the determination unit 81.

The detection unit 87 both confirms whether or not the total generated power or the total output current of each power generation unit 78 satisfies a predetermined condition, and acquires information indicating the occurrence of an overloaded state from the PCS 8. It may be a configuration.

In this case, for example, when the total generated power or the total output current of each power generation unit 78 satisfies the predetermined condition and the detection unit 87 acquires the information indicating the occurrence of the overload state from the PCS8, the overload state is changed. Judge that it has occurred. Alternatively, for example, when the detection unit 87 satisfies the predetermined condition for the total generated power or the total output current of each power generation unit 78, or when the information indicating the occurrence of the overload state is acquired from the PCS 8, the overload state is changed. Judge that it has occurred.

FIG. 10 is a diagram showing the relationship between the output current and the output voltage of the power generation unit in the power generation state determination system according to the embodiment of the present invention. In FIG. 10, the horizontal axis represents voltage and the vertical axis represents current.

With reference to FIG. 10, graph A1 shows the relationship between the output current and the output voltage of the normal power generation unit 78. Graph A2 shows, for example, the relationship between the output current and the output voltage of the power generation unit 78 (hereinafter, also referred to as an abnormal power generation unit) having a low open circuit voltage and a possibility of abnormality. Here, it is assumed that the normal power generation unit 78 and the abnormal power generation unit are connected in parallel.

In the power generation unit 78, the current and voltage are controlled so that the generated power is maximized by maximum power point tracking (MPPT).

The point Pma in the graph A1 is the maximum power point of the normal power generation unit 78, that is, the point where the generated power is the maximum. At the point Pma, the output voltage of the power generation unit 78 is Vpm, and the output current is Ipma.

The point Pmb in the graph A2 is the maximum power point of the abnormal power generation unit. At the point Pmb, the output voltage of the abnormal power generation unit is Vpm, and the output current is Ipmb.

As shown in Graph A1, when an overload state occurs in the normal power generation unit 78, the output voltage of the power generation unit 78 becomes a Voc larger than Vpm. Further, the output current of the power generation unit 78 is Ioca, which is smaller than Ipma.

As shown in Graph A2, when an overloaded state occurs in the abnormal power generation unit, the output voltage becomes Voc and becomes larger than Vpm. The output current is Iocb, which is smaller than Ipmb.

As shown in FIG. 10, the fluctuation of the output current of the abnormal power generation unit when transitioning from the normal state to the overloaded state, that is, the difference d2 between Ipmb and Iocb is the normal power generation when transitioning from the normal state to the overloaded state. The fluctuation of the output current of the unit 78, that is, the difference d1 between Ipma and Ioca becomes larger.

FIG. 11 is a diagram showing an example of the output currents of the normal power generation unit and the abnormal power generation unit in the overloaded state. In FIG. 11, the horizontal axis represents time and the vertical axis represents output current.

With reference to FIG. 11, graph A3 shows the output current of the normal power generation unit 78. Graph A4 shows the output current of the abnormal power generation unit.

As shown in Graphs A3 and A4, the fluctuation of the output current of the abnormal power generation unit in the transition from the normal state to the overloaded state is larger than the fluctuation of the output current of the normal power generation unit 78.

The determination unit 81 determines the abnormality of the corresponding power generation unit 78 based on the fluctuation of the output current when such an overload state occurs.

More specifically, the determination unit 81 calculates the average value of the measured values of the current sensor 16 received from the acquisition unit 86 in the overload period for each current sensor 16.

Then, the determination unit 81 calculates the fluctuation amount Ic of the measured value for each current sensor 16 by subtracting the calculated corresponding average value from the measured value of the current sensor 16 at the time immediately before the overload period.

For example, when the calculated fluctuation amount Ic is equal to or higher than the predetermined threshold Th2, the determination unit 81 determines that the corresponding power generation unit 78 is abnormal.
[Operation flow]
Each device in the monitoring system 301 includes a computer, and an arithmetic processing unit such as a CPU in the computer reads a program including a part or all of each step in the following flowchart from a memory (not shown) and executes the program. The programs of these plurality of devices can be installed from the outside. The programs of these plurality of devices are distributed in a state of being stored in a recording medium.

FIG. 12 is a flowchart defining an operation procedure when the determination device according to the embodiment of the present invention determines an abnormality related to the power generation unit.

With reference to FIG. 12, first, the determination device 101 detects the overloaded state (step S101).

Next, the determination device 101 acquires the measured value of the current of each power generation unit 78 in the overload period and the measured value of the current in the time immediately before the overload period from the monitoring information stored by itself ( Step S102).

Next, the determination device 101 calculates the average value of the measured values in the acquired overload period for each current sensor 16 (step S103).

Next, the determination device 101 subtracts the calculated corresponding average value from the measured value of the current in the time immediately before the overload period for each current sensor 16, so that the fluctuation amount Ic of the measured value of the current sensor 16 Is calculated (step S104).

Next, when the calculated fluctuation amount Ic is equal to or greater than the predetermined threshold value Th2 (YES in step S105), the determination device 101 determines that the corresponding power generation unit 78 is abnormal (step S106).

On the other hand, when the calculated fluctuation amount Ic is less than the predetermined threshold value Th2 (NO in step S105), the determination device 101 determines that the corresponding power generation unit 78 is normal (step S107).

Next, when the determination device 101 makes an abnormality determination for all the power generation units 78 (YES in step S108), the determination device 101 ends the abnormality determination.

On the other hand, when the determination device 101 has not made an abnormality determination for all the power generation units 78 (NO in step S108), the determination device 101 makes an abnormality determination for the other power generation units 78 (step S105).

By the way, a technique capable of improving the abnormality determination of the photovoltaic power generation system beyond the technique described in Patent Document 1 is desired.

In the determination device according to the embodiment of the present invention, the acquisition unit 86 acquires a plurality of measurement information indicating the measurement results of the output currents of the plurality of power generation units 78. The detection unit 87 detects the occurrence of an overloaded state of the photovoltaic power generation system 401. The determination unit 81 determines an abnormality of the power generation unit 78 corresponding to the output current based on the fluctuation of the output current when the overload state occurs.

With such a configuration, in the photovoltaic power generation system 401, the phenomenon that occurs in the overloaded state can be focused on, and the power generation unit 78 suspected of being abnormal can be satisfactorily detected.

Therefore, the determination device according to the embodiment of the present invention can improve the abnormality determination of the photovoltaic power generation system.

Further, in the determination device according to the embodiment of the present invention, the detection unit 87 is overloaded when the total generated power based on the output current of each power generation unit 78 or the total output current satisfies a predetermined condition. Judge.

With such a configuration, in the photovoltaic power generation system 401, the occurrence of an overloaded state is detected by using the measurement results of each power generation unit 78 without acquiring information on whether or not the solar power generation system 401 is overloaded. be able to.

Further, in the determination device according to the embodiment of the present invention, the detection unit 87 acquires information indicating the occurrence of an overloaded state from the PCS 8.

With such a configuration, the occurrence of the overloaded state can be detected more reliably in the photovoltaic power generation system 401.

Further, in the photovoltaic power generation system 401 according to the embodiment of the present invention, the determination device 101 acquires a plurality of measurement information indicating the measurement results of the output currents of the plurality of power generation units 78. Further, the determination device 101 detects the occurrence of a state due to the overloading of the photovoltaic power generation system 401, and based on the fluctuation of the output current when the state occurs, the power generation unit corresponding to the output current. Judge 78 abnormalities.

With such a configuration, in the photovoltaic power generation system 401, the phenomenon that occurs in the overloaded state can be focused on, and the power generation unit 78 suspected of being abnormal can be satisfactorily detected.

Therefore, in the photovoltaic power generation system 401 according to the embodiment of the present invention, it is possible to improve the abnormality determination of the photovoltaic power generation system 401.

Further, in the determination method according to the embodiment of the present invention, first, the occurrence of an overloaded state of the photovoltaic power generation system 401 is detected. Next, based on the fluctuation of the output currents of the plurality of power generation units 78 when the overload state occurs, the abnormality of the power generation unit 78 corresponding to the output current is determined.

With such a configuration, in the photovoltaic power generation system 401, the phenomenon that occurs in the overloaded state can be focused on, and the power generation unit 78 suspected of being abnormal can be satisfactorily detected.

Therefore, the determination method according to the embodiment of the present invention can improve the abnormality determination of the photovoltaic power generation system.

It should be considered that the above embodiments are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and it is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

The above description includes the features described below.
[Appendix 1]
A determination device used in a photovoltaic power generation system having a plurality of power generation units including a solar cell panel.
An acquisition unit that acquires a plurality of measurement information indicating the measurement results of the output currents of the plurality of power generation units, respectively.
A detector that detects the occurrence of a state caused by overloading of the photovoltaic power generation system, and
A determination unit for determining an abnormality of the power generation unit corresponding to the output current based on the fluctuation of the output current when the state occurs is provided.
The power generation unit is a string in which a plurality of solar cell panels are connected in series.
The determination unit is a determination device that determines a corresponding abnormality of the power generation unit by comparing the fluctuation of the output current in the power generation unit with the fluctuation of the output current in another power generation unit.

1 Output line 2, 4, 5 Aggregate line 3 Internal line 6 Cubicle 7 Copper bar 8 PCS
9 Power conversion unit 11 Acquisition unit 14 Communication unit 16 Current sensor 17 Voltage sensor 26 Power supply line 46 Signal line 60 Current collection unit 71 Current collection box 72,73,77 Copper bar 74 Solar cell unit 76 Connection box 78 Power generation unit 79 Solar cell Panel 80 PCS unit 81 Judgment unit 84 Communication processing unit 85 Storage unit 86 Acquisition unit 87 Detection unit 101 Judgment device 111 Monitoring device 151 Collection device 301 Monitoring system 401 Solar power generation system

Claims (5)

A determination device used in a photovoltaic power generation system having a plurality of power generation units including a solar cell panel.
An acquisition unit that acquires a plurality of measurement information indicating the measurement results of the output currents of the plurality of power generation units, respectively.
A detector that detects the occurrence of a state caused by overloading of the photovoltaic power generation system, and
A determination device including a determination unit that determines an abnormality of the power generation unit corresponding to the output current based on a fluctuation of the output current when the state occurs. The determination device according to claim 1, wherein the detection unit determines that the state has occurred when the total power generation based on the output current of each power generation unit or the total output current satisfies a predetermined condition. The output lines from each of the power generators are electrically connected to the power converter.
The determination device according to claim 1 or 2, wherein the detection unit acquires information indicating the occurrence of the state from the power conversion device. With multiple power generators, including solar panels,
It is a photovoltaic power generation system equipped with a judgment device.
The determination device acquires a plurality of measurement information indicating the measurement results of the output currents of the plurality of power generation units, detects the occurrence of a state due to overloading of the photovoltaic power generation system, and the state occurs. A photovoltaic power generation system that determines an abnormality of the power generation unit corresponding to the output current based on the fluctuation of the output current in the case of. It is a judgment method in a judgment device used in a photovoltaic power generation system having a plurality of power generation units including a solar cell panel.
A step of detecting the occurrence of a state caused by overloading of the photovoltaic power generation system, and
A determination method including a step of determining an abnormality of the power generation unit corresponding to the output current based on fluctuations in output currents of the plurality of power generation units when the state occurs.

Images