WO2019150777A1

WO2019150777A1 - Monitoring device and determining method

Info

Publication number: WO2019150777A1
Application number: PCT/JP2018/045592
Authority: WO
Inventors: 谷村晃太郎; 近藤麻由; 池上洋行; 下口剛史
Original assignee: 住友電気工業株式会社
Priority date: 2018-02-02
Filing date: 2018-12-12
Publication date: 2019-08-08
Also published as: DE112018007008T5; JP7226338B2; JPWO2019150777A1

Abstract

This monitoring device is to be used in a photovoltaic power generation system wherein an output line from a power generation unit, which includes a solar cell panel, is electrically connected to a power conversion device. The monitoring device is provided with: an acquisition unit that acquires measurement results of a current of the power generation unit; and a determining unit, which identifies the operation state of the power conversion device on the basis of the measurement results, and determines an abnormality on the basis of the operation state thus identified, and the measurement results.

Description

Monitoring device and determination method

The present invention relates to a monitoring device and a determination method.
This application claims priority based on Japanese Patent Application No. 2018-16842 filed on Feb. 2, 2018, the entire disclosure of which is incorporated herein.

JP 2012-205078 A (Patent Document 1) discloses a monitoring system for photovoltaic power generation as follows. That is, the photovoltaic power generation monitoring system is a photovoltaic power generation monitoring system that monitors the power generation status of the solar cell panel for a photovoltaic power generation system that aggregates outputs from a plurality of solar cell panels and sends them to a power converter. A measuring device for measuring the power generation amount of each solar cell panel provided in a place where the output electric circuits from the plurality of solar cell panels are aggregated, and connected to the measurement device, 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 solar cell panel via the upper communication device And a management device having a function of collecting the measurement data for each. The management device determines the presence or absence of abnormality based on the difference in power generation amount at the same time for each solar cell panel, or the maximum value or integration of the power generation amount for a predetermined period for each solar cell panel The presence or absence of abnormality is determined based on the value.

JP 2012-205078 A

(1) The monitoring device of the present disclosure is a monitoring device used in a solar power generation system in which an output line from a power generation unit including a solar battery panel is electrically connected to a power conversion device, and the current of the power generation unit An acquisition unit that acquires the measurement result of the power converter, and a determination unit that determines an operation state of the power converter based on the measurement result and determines an abnormality based on the determined operation state and the measurement result.

(7) The determination method of the present disclosure is a determination method in a monitoring device used in a solar power generation system in which an output line from a power generation unit including a solar battery panel is electrically connected to a power conversion device. Obtaining a current measurement result of the unit; determining an operation state of the power converter based on the measurement result; determining an abnormality based on the determined operation state and the measurement result; including.

One aspect of the present disclosure can be realized not only as a monitoring apparatus including such a characteristic processing unit, but also as a program for causing a computer to execute such characteristic processing. In addition, one embodiment of the present disclosure can be realized as a semiconductor integrated circuit that realizes part or all of the monitoring device, or can be realized as a system including the monitoring device.

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 the PCS unit according to the embodiment of the present invention. FIG. 3 is a diagram showing a configuration of the current collecting unit according to the embodiment of the present invention. FIG. 4 is a diagram showing a configuration of the solar cell unit according to the embodiment of the present invention. FIG. 5 is a diagram showing a configuration of the power generation state determination system according to the embodiment of the present invention. FIG. 6 is a diagram illustrating a configuration of a monitoring device in the power generation state determination system according to the embodiment of the present invention. FIG. 7 is a diagram showing an example of normal string current data in the power generation state determination system according to the embodiment of the present invention. FIG. 8 is a diagram illustrating an example of a state in which an output line from the power generation unit in the photovoltaic power generation system according to the embodiment of the present invention is short-circuited between positive and negative electrodes. FIG. 9 is a diagram showing an example of string current data in the output line short-circuited between the positive and negative electrodes in the power generation state determination system according to the embodiment of the present invention. FIG. 10 is a diagram showing a short-circuit failure state of the backflow prevention diode in the power generation state determination system according to the embodiment of the present invention. FIG. 11 is a diagram illustrating an example of string current data of the power generation unit corresponding to the backflow prevention diode having a short circuit failure in the power generation state determination system according to the embodiment of the present invention. FIG. 12 is a diagram illustrating another example in which the output line from the power generation unit in the solar power generation system according to the embodiment of the present invention is short-circuited between the positive and negative electrodes. FIG. 13 is a diagram showing another example of string current data in the output line in which the positive and negative electrodes are short-circuited in the power generation state determination system according to the embodiment of the present invention. FIG. 14 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. 15 is a flowchart that defines an operation procedure when the monitoring apparatus according to the embodiment of the present invention performs abnormality determination. FIG. 16 is a flowchart defining an operation procedure when the monitoring apparatus according to the embodiment of the present invention performs abnormality determination in the PCS stop state. FIG. 17 is a flowchart that defines an operation procedure when the monitoring apparatus according to the embodiment of the present invention performs abnormality determination in the operating state of the PCS.

In recent years, techniques for monitoring solar power generation systems and determining abnormalities have been developed.

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

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

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

[Description of Embodiment of Present Invention]
First, the contents of the embodiment of the present invention will be listed and described.

(1) A monitoring device according to an embodiment of the present invention is a monitoring device used in a photovoltaic power generation system in which an output line from a power generation unit including a solar battery panel is electrically connected to a power conversion device, An acquisition unit that acquires a measurement result of the current of the power generation unit, a determination that determines an operation state of the power converter based on the measurement result, and determines an abnormality based on the determined operation state and the measurement result A part.

With such a configuration, the operation state of the power conversion device is determined using the current measurement result of the power generation unit, and the abnormality determination is performed using the current measurement result of the power generation unit and according to the determination result. be able to. Thereby, the abnormality in a solar power generation system can be determined favorable. Therefore, the abnormality determination of the solar power generation system can be improved.

(2) Preferably, the determination unit determines that the operating state of the power converter is in a stopped state, and determines an abnormality based on the measurement result in the stopped state.

Thus, paying attention to the measurement result of the current of the power generation unit when the power conversion device is stopped, the configuration for determining the abnormality using the measurement result of the output current of the power generation unit makes a good determination of the abnormality in the photovoltaic power generation system can do.

(3) More preferably, a measurement unit that measures a current of the power generation unit is connected between the power generation unit and the power conversion device, and the determination unit indicates the measurement result indicating an output current of the power generation unit. Based on the above, a circuit abnormality between the measurement unit and the power converter is determined.

With such a configuration, it is possible to satisfactorily determine an abnormality in a circuit between the measurement unit and the power converter using the measurement result of the output current of the power generation unit.

(4) More preferably, in the photovoltaic power generation system, output lines from the plurality of power generation units are aggregated in the aggregation unit and electrically connected to the power converter, and a backflow prevention diode is connected to the plurality of power generation units. Among the units, a measuring unit that is connected between a part or all of the power generation units and the aggregation unit and measures a current of the corresponding power generation unit is a counter current corresponding to the part or all of the power generation units. The determination unit is connected to a prevention diode, and the determination unit determines an abnormality of the backflow prevention diode based on the measurement result indicating a backflow current to the part or all of the power generation units.

With such a configuration, it is possible to satisfactorily determine the abnormality of the backflow prevention diode using the measurement result of the backflow current to the power generation unit.

(5) Preferably, the measurement part which measures the electric current of the said electric power generation part is connected between the said electric power generation part and the said power converter device, and the said determination part is an operation state for the said power converter device. And determining an abnormality in the circuit between the power generation unit and the measurement unit based on the measurement result indicating the output current of the power generation unit in the operating state of the power converter.

Thus, paying attention to the current measurement result of the power generation unit in the operating state of the power conversion device, the configuration for determining the abnormality using the measurement result of the output current of the power generation unit, the circuit abnormality between the power generation unit and the measurement unit Can be determined satisfactorily.

(6) More preferably, in the photovoltaic power generation system, output lines from a plurality of the power generation units are aggregated in the aggregation unit and electrically connected to the power conversion device, and current of the corresponding power generation unit is measured. A measuring unit is connected between a part or all of the plurality of power generation units among the plurality of power generation units and the power conversion device, and the determination unit is configured to operate the one of the plurality of power generation units in an operating state of the power conversion device. An abnormality in a circuit between the measurement unit and the aggregation unit is determined on the basis of the measurement result indicating the output current of a part or all of the plurality of power generation units.

Thus, paying attention to the measurement result of the current of the power generation unit in the operating state of the power conversion device, the configuration of determining abnormality using the measurement result of the output current of each power generation unit, the circuit between the measurement unit and the aggregation unit Abnormality can be determined satisfactorily.

(7) The determination method according to the embodiment of the present invention is a determination method in a monitoring device used in a photovoltaic power generation system in which an output line from a power generation unit including a solar battery panel is electrically connected to a power conversion device. A step of acquiring a current measurement result of the power generation unit, a step of determining an operation state of the power converter based on the measurement result, an abnormality based on the determined operation state, and the measurement result Determining.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated. Moreover, you may combine arbitrarily at least one part of embodiment described below.

[Configuration of solar 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.

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

FIG. 1 representatively shows four PCS units 80, but a larger or smaller number of PCS units 80 may be provided.

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

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

In FIG. 2, four current collecting units 60 are representatively shown, but a larger or smaller number of current collecting units 60 may be provided.

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

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

In FIG. 3, four solar cell units 74 are representatively shown, but a larger number or a smaller number of solar cell units 74 may be provided.

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

Referring to FIG. 4, solar cell unit 74 includes four power generation units 78 A, 78 B, 78 C, 78 D and connection box 76. The power generation unit 78 includes a solar cell panel 79. The connection box 76 has a copper bar 77. Hereinafter, each of the

power generation units

78A, 78B, 78C, and 78D is also referred to as a power generation unit 78.

FIG. 4 representatively shows four power generation units 78, but a larger or smaller number of power generation units 78 may be provided.

The power generation unit 78 is a string in which four solar cell panels 79 are connected in series in this example.

FIG. 4 representatively shows four solar cell panels 79, but a larger or smaller number of solar cell panels may be provided.

In the solar power generation system 401, output lines and aggregated lines, that is, power lines from the plurality of power generation units 78 are electrically connected to the cubicles 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 an aggregation line 5 via a copper bar 77. The copper bar 77 is provided, for example, inside the connection box 76.

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

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

With reference to FIGS. 1 to 4, in the photovoltaic power generation system 401, as described above, the output lines 1 from the plurality of power generation units 78 are aggregated into the aggregation line 5, and the aggregation lines 5 are aggregated into the aggregation line 2. Then, each aggregation line 2 is aggregated to 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 the 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 conversion unit 9.

In the PCS 8, the power conversion unit 9 uses, for example, the DC power generated in 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. Is received, 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, 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 Power Generation State Determination System 301]
FIG. 5 is a diagram showing a configuration of the power generation state determination system according to the embodiment of the present invention.

Referring to FIG. 5, the solar power generation system 401 includes a power generation state determination system 301. The power generation state determination system 301 includes a management device 101, a plurality of monitoring devices 111, and a collection device 151.

FIG. 5 representatively shows four monitoring devices 111 provided corresponding to one current collecting unit 60, but a larger or smaller number of monitoring devices 111 may be provided. In addition, the power generation state determination system 301 includes one collection device 151, but may include a plurality of collection devices 151.

In the power generation state determination system 301, sensor information in the monitoring device 111 as a slave is transmitted to the collection device 151 regularly or irregularly.

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

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

The collection device 151 collects the measurement results of each monitoring device 111. The collection device 151 is provided in the vicinity of the PCS 8, for example. More specifically, the collection 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 collection device 151 perform transmission and reception of information by performing power line communication (PLC: Power Line Communication) via the

aggregation lines

2 and 5.

More specifically, each monitoring device 111 transmits monitoring information indicating the current and voltage measurement results and abnormality determination results of the corresponding output line.

The collection device 151 can send and receive information via the

aggregation lines

2 and 5. Specifically, the collection device 151 performs power line communication with the monitoring device 111 via the signal line 46 and the

aggregation lines

2 and 5, for example, and receives monitoring information from the monitoring device 111.

The collection device 151 transmits and receives information to and from other devices such as the management device 101 via the network.

[Configuration of Monitoring Device 111]
FIG. 6 is a diagram illustrating a configuration of a monitoring device in the power generation state determination system according to the embodiment of the present invention. In FIG. 6, the inside of the junction box 76 is shown in more detail.

Referring to FIG. 6, the connection box 76 includes an aggregation portion 91, switches 93 A, 93 B, 93 C, 93 D, backflow prevention diodes 94 A, 94 B, 94 C, 94 D, an output line 1, an aggregation line 5. A copper bar 77.

Hereinafter, each of the

switches

93A, 93B, 93C, and 93D is also referred to as a switch 93, and each of the

backflow prevention diodes

94A, 94B, 94C, and 94D is also referred to as a backflow prevention diode 94.

Each of the output lines 1 includes plus side output lines 1pa, 1pb, 1pc and minus side output lines 1na, 1nb.

The aggregation line 5 includes a plus-side aggregation line 5p and a minus-side aggregation line 5n. The aggregation unit 91 includes a copper bar 77 and aggregates the output lines 1 from the plurality of power generation units 78. The copper bar 77 has a plus side copper bar 77p and a minus side copper bar 77n.

Although not shown, the copper bar 72 in the current collection 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 backflow prevention diode 94 is connected between the power generation unit 78 and the aggregation unit 91.

More specifically, the plus side output line 1pa has a first end connected to the corresponding power generation unit 78 and a second end connected to the corresponding switch 93. The plus side output line 1pb has a first end connected to the corresponding switch 93 and a second end connected to the anode of the corresponding backflow prevention diode 94. The positive side output line 1pc has a first end connected to the cathode of the corresponding backflow prevention diode 94 and a second end connected to the corresponding positive side copper bar 77p.

The negative output line 1na has a first end connected to the corresponding power generation unit 78 and a second end connected to the corresponding switch 93. The minus side output line 1nb has a first end connected to the corresponding switch 93 and a second end connected to the minus side copper bar 77n.

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

The monitoring device 111 includes an acquisition unit 11, a communication unit 14, a determination unit 15, a voltage sensor 17, a storage unit 18, and a measurement unit 19. The measurement unit 19 includes four current sensors 16. Note that 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 in the vicinity of the power generation unit 78, for example. Specifically, the monitoring device 111 is provided, for example, inside a connection box 76 provided with a copper bar 77 to which the output line 1 to be measured is connected. Note that the monitoring device 111 may be provided outside the connection box 76.

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

The acquisition unit 11 acquires the current measurement result of the power generation unit 78. More specifically, the acquisition unit 11 acquires a measurement result indicating the current of the output line 1 measured by the current sensor 16.

Specifically, the current sensor 16 is, for example, a Hall element type current probe. The current sensor 16 is connected between the power generation unit 78 and the PCS 8 and uses the electric power received from the power supply circuit (not shown) of the monitoring device 111 to cause the current flowing through the corresponding positive output line 1p to be, for example, every predetermined time. Measure and output a signal indicating the measurement result to the acquisition unit 11. The current sensor 16 may measure the current flowing through the negative output line 1n.

The voltage sensor 17 measures the voltage of the output line 1 every predetermined time, for example. More specifically, the voltage sensor 17 measures the voltage between the plus side copper bar 77p and the minus side copper bar 77n, and outputs a signal indicating the measurement result to the acquisition unit 11.

The acquisition unit 11 includes a measurement result included in each signal received from the current sensor 16 and the voltage sensor 17, 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, referred to as “current sensor ID”). Is also stored in the storage unit 18.

The determination unit 15 determines the operation state of the PCS 8 based on the measurement result of the power generation unit 78, and determines an abnormality based on the determined operation state and the measurement result of the power generation unit 78.

For example, the determination unit 15 determines an abnormality based on the current measurement result of the power generation unit 78 when the PCS 8 is stopped.

[Abnormality judgment 1]
For example, the determination unit 15 determines an abnormality in the circuit between the measurement unit 19 and the PCS 8 based on a measurement result indicating the output current of the power generation unit 78.

Specifically, for example, the determination unit 15 acquires each measurement result of the current sensor 16 having the same current sensor ID from the storage unit 18 every day, and arranges the acquired measurement results in time series. Create string current data.

FIG. 7 is a diagram showing an example of normal string current data in the power generation state determination system according to the embodiment of the present invention. In FIG. 7, the horizontal axis indicates time, and the vertical axis indicates the measurement result of the current sensor 16, that is, the current value.

Referring to FIG. 7, in the output line 1, no current flows until time t 1, current corresponding to the generated power in the corresponding power generation unit 78 flows from time t 1 to evening time t 2, and current after time t 2. Does not flow.

The PCS 8 is operated by the electric power generated by the power generation unit 78, for example. Monitoring device 111 determines whether PCS 8 is in an operating state or a stopped state from the measurement results included in the signals received from each of current sensor 16 and voltage sensor 17.

More specifically, the determination unit 15 in the monitoring device 111 is electrically connected to the PCS 8 measured by the current sensor 16 and the voltage measured by the voltage sensor 17 is sufficient to operate the PCS 8. When the total current flowing through the output line 1 is sufficient to operate the PCS 8, it is determined that the PCS 8 is in an operating state.

Specifically, for example, the determination unit 15 acquires the measurement results of the current sensor 16 and the voltage sensor 17 from the storage unit 18 every day, and arranges the acquired measurement results in time series.

And the determination part 15 discriminate | determines the operation state of PCS8 based on the measurement result of the electric power generation part 78. FIG.

Specifically, the determination unit 15 determines that the operating state of the PCS 8 is in the operating state in a time zone in which the voltage is equal to or higher than a predetermined value and the current is equal to or higher than the predetermined value from the measurement results arranged in time series. It is determined that the operation state of the PCS 8 is the stop state in the time zone excluding the zone.

In the example of FIG. 7, the determination unit 15 determines that the PCS 8 is in an operating state during a period from time t1 to time t2.

The PCS 8 stops power conversion until the morning time t1 because power that can operate the PCS 8 is not supplied from the power generation unit 78.

At this time, since the PCS 8 has a high impedance, no current flows through the output line 1 electrically connected to the PCS 8.

From the time t1 in the morning to the time t2 in the evening, power that can operate the PCS 8 is supplied from the power generation unit 78, so that a current flows through the output line 1.

After the evening time t2, the PCS 8 stops power conversion because the power that can be used by the PCS 8 is not supplied from the power generation unit 78.

FIG. 8 is a diagram illustrating an example of a state in which the output line from the power generation unit in the solar power generation system according to the embodiment of the present invention is short-circuited between the positive and negative electrodes.

Referring to FIG. 8, for example, in the stop state of PCS 8 before morning time t 1 and after evening time t 2, plus-side output line 1 pb and minus-side output line 1 nb are short-circuited between current sensor 16 and PCS 8. The current I1 flows through the output line 1.

FIG. 9 is a diagram showing an example of string current data in the output line short-circuited between the positive and negative electrodes in the power generation state determination system according to the embodiment of the present invention. In FIG. 9, the horizontal axis indicates time, and the vertical axis indicates the measurement result of the current sensor 16, that is, the current value.

Referring to FIG. 9, graph D1 is the same as the graph shown in FIG. 7, and shows an example of normal string current data. Graph D2 shows an example of string current data in the output line shorted between the positive and negative electrodes.

In the graph D2, the current flowing through the output line 1 before time t1 and after time t2 can be confirmed.

For example, when the current flowing through the output line 1 is greater than or equal to a predetermined value before the time t1 when the PCS 8 is in a stopped state and after the time t2, the determination unit 15 includes a circuit between the measurement unit 19 including the current sensor 16 and the PCS 8. Judged to be abnormal.

That is, the determination unit 15 can detect a short circuit between the positive and negative electrodes between the measurement unit 19 and the PCS 8.

The determination unit 15 outputs to the communication unit 14 monitoring information that associates the determination result indicating the circuit abnormality between the determined measurement unit 19 and the PCS 8, the string current data, and the measurement result of the voltage sensor 17.

The communication unit 14 can perform power line communication via the aggregation line with the collection device 151 that collects the measurement results of the plurality of monitoring devices 111. More specifically, the communication unit 14 can transmit 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 line 26 and the

aggregation lines

2 and 5.

The communication unit 14 transmits the monitoring information received from the determination unit 15 to the collection device 151.

[Abnormality judgment 2]
For example, the determination unit 15 determines abnormality of the backflow prevention diode based on the measurement result indicating the backflow current to the power generation unit 78 in the stop state of the PCS 8.

FIG. 10 is a diagram showing a short-circuit failure state of the backflow prevention diode in the power generation state determination system according to the embodiment of the present invention.

Referring to FIG. 10, for example, the backflow prevention diode 94A is short-circuited, and the output voltage of the power generation unit 78A electrically connected to the failed backflow prevention diode 94 is affected by shadows, dirt, parallel arcs, ground faults, and the like. When the voltage decreases due to factors such as initial failure, the output current I2 of the other three

power generation units

78B, 78C, 78D flows into the power generation unit 78A.

FIG. 11 is a diagram showing an example of string current data of the power generation unit corresponding to the backflow prevention diode having a short circuit failure in the power generation state determination system according to the embodiment of the present invention. In FIG. 11, the horizontal axis indicates time, and the vertical axis indicates the measurement result of the current sensor 16, that is, the current value.

Referring to FIG. 11, graph D3 shows string current data of power generation unit 78B that is normal power generation unit 78, and graph D4 shows power generation unit 78A that is power generation unit 78 corresponding to the short-circuit backflow prevention diode. String current data is shown.

In the current sensor 16 corresponding to the power generation unit 78B, for example, when the backflow prevention diode 94A corresponding to the power generation unit 78A fails due to, for example, a short circuit and the voltage of the power generation unit 78A decreases, the PCS 8 is stopped, that is, at time t1. Before and after time t2, the output current of the power generation unit 78B is measured.

In the current sensor 16 corresponding to the power generation unit 78A, a negative current value, that is, a reverse current to the power generation unit 78A is measured before time t1 and after time t2.

For example, when a reverse current flows through the output line 1 in the stop state of the PCS 8, the determination unit 15 determines that the reverse current prevention diode 94 corresponding to the output line 1 is abnormal.

That is, the determination unit 15 can detect a short circuit failure of the backflow prevention diode 94.

The determination unit 15 outputs the determination result indicating the determined abnormality of the backflow prevention diode 94 and the monitoring information in which the string current data and the measurement result of the voltage sensor 17 are associated with each other to the communication unit 14.

[Abnormality judgment 3]
The determination unit 15 determines, for example, an abnormality in the circuit between the power generation unit 78 and the measurement unit 19 based on a measurement result indicating the output current of the power generation unit 78 in the operating state of the PCS 8.

FIG. 12 is a diagram showing another example of a state in which the output line from the power generation unit in the photovoltaic power generation system according to the embodiment of the present invention is short-circuited between the positive and negative electrodes.

Referring to FIG. 12, for example, in the operating state of PCS 8, when plus side output line 1pb and minus side output line 1nb are short-circuited between power generation unit 78 and measurement unit 19, plus side output line 1pa causes plus side output. The current that flows to the line 1pb branches into a current I3a that flows through the short-circuited portion and a current I3b that flows to the aggregation unit 91. The current I3b is much smaller than the current I3a.

FIG. 13 is a diagram showing another example of string current data in the output line short-circuited between the positive and negative electrodes in the power generation state determination system according to the embodiment of the present invention. In FIG. 13, the horizontal axis indicates time, and the vertical axis indicates the measurement result of the current sensor 16, that is, the current value.

Referring to FIG. 13, as shown in graph D5, the current flowing through output line 1 decreases after time t3 because the output line has a short circuit between positive and negative electrodes at time t3.

For example, when the current flowing through the output line 1 or the like is less than a predetermined value in at least a part of the period from time t1 to time t2 in which the PCS 8 is operating, the determination unit 15 is connected between the power generation unit 78 and the measurement unit 19. Is determined to be abnormal.

That is, the determination unit 15 can detect a short circuit between the positive and negative electrodes between the power generation unit 78 and the measurement unit 19.

The determining unit 15 outputs to the communication unit 14 monitoring information that associates the determined determination result indicating the abnormality of the circuit between the power generation unit 78 and the measuring unit 19, the string current data, and the measurement result of the voltage sensor 17.

[Abnormality judgment 4]
The determination part 15 determines the abnormality of the circuit between the measurement part 19 and the aggregation part 91 based on the measurement result which shows the output current of the electric power generation part 78 in the operating state of PCS8, for example.

Referring to FIG. 9 again, as shown in graphs D1 and D2, in the operating state of PCS 8, that is, in the period from time t1 to time t2, the current flowing through output line 1 short-circuited between the positive and negative electrodes is a normal output. It becomes larger than the current flowing through the line 1.

FIG. 14 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. 14, the horizontal axis represents voltage, and the vertical axis represents current.

Referring to FIG. 14, in power generation unit 78, current and voltage are controlled by maximum power point tracking (MPPT: Maximum Power Point Tracking) so that the generated power is maximized.

The point pm shown in FIG. 14 is a point at which the generated power is maximized. At this time, the output voltage of the power generation unit 78 is Vpm, and the output current of the power generation unit 78 is Ipm.

In the power generation unit 78 in which a short circuit between the positive and negative electrodes occurs, for example, the output voltage decreases to Vsc. At this time, the output current at which the generated power is maximum is Isc, which is larger than Ipm. For this reason, as shown in the graph D1 and the graph D2 shown in FIG. 9, the current flowing through the output line 1 short-circuited between the positive and negative electrodes is larger than the current flowing through the normal output line 1.

For example, in the operating state of the PCS 8, the determination unit 15 compares the current flowing through each output line 1, and the circuit corresponding to the output line 1 in which a current larger than the current flowing through the other output lines 1 flows is abnormal. Is determined.

More specifically, the determination unit 15 creates string current data for each power generation unit 78. And the determination part 15 calculates the average value AVE of the electric current value of each electric power generation part 78 in the time t4 of the period from the time t1 to the time t2. The time t4 is, for example, the time when the output current of a certain power generation unit 78 becomes maximum in one day.

When the current value at time t4 of the power generation unit 78 is larger than the average value AVE by the determination unit 15, the circuit between the measurement unit 19 and the aggregation unit 91 in the output line 1 corresponding to the power generation unit 78 is abnormal. Is determined.

That is, the determination unit 15 can detect a short circuit between the positive and negative electrodes between the measurement unit 19 and the aggregation unit 91.

The determination unit 15 outputs to the communication unit 14 monitoring information in which the determination result indicating the abnormality of the circuit between the determined measurement unit 19 and the aggregation unit 91, the string current data, and the measurement result of the voltage sensor 17 are associated.

[Flow of operation]
Each device in the power generation state determination system 301 includes a computer, and an arithmetic processing unit such as a CPU in the computer reads and executes a program including a part or all of each step of the following flowchart from a memory (not shown). Each of the programs of the plurality of apparatuses can be installed from the outside. The programs of the plurality of apparatuses are distributed while being stored in a recording medium.

FIG. 15 is a flowchart that defines an operation procedure when the monitoring apparatus according to the embodiment of the present invention performs abnormality determination.

Referring to FIG. 15, first, the monitoring device 111 acquires current and voltage measurement results of the

power generation units

78A, 78B, 78C, and 78D (step S101).

Next, the monitoring device 111 determines the operating state of the PCS 8 based on the acquired measurement result. More specifically, the monitoring device 111 determines a time zone in which the PCS 8 is in an operating state and a time zone in which the PCS 8 is in a stopped state based on the acquired measurement result (step S102).

Next, the monitoring device 111 creates string current data of each power generation unit 78 from the acquired measurement result (step S103).

Next, the monitoring device 111 makes an abnormality determination based on the measurement result in the time zone in which the PCS 8 is stopped (step S104).

Next, the monitoring device 111 performs abnormality determination based on the measurement result in the time zone in which the PCS 8 is in operation (step S105).

Next, the monitoring device 111 acquires new measurement results of the currents and voltages of the

power generation units

78A, 78B, 78C, and 78D (step S101).

The order of step S102 and step S103 is not limited to the above, and the order may be changed.

Further, the order of step S104 and step S105 is not limited to the above, and the order may be changed.

FIG. 16 is a flowchart that defines an operation procedure when the monitoring apparatus according to the embodiment of the present invention performs abnormality determination in the PCS stop state.

Referring to FIG. 16, first, the monitoring device 111 starts abnormality determination for a certain power generation unit 78. When the reverse current is measured in the stop state of the PCS 8 (YES in step S201), the monitoring device 111 determines that the short circuit failure of the backflow prevention diode 94 in the corresponding output line 1 is abnormal (step S202).

Next, the monitoring device 111 transmits monitoring information including the determination result, the string current data, and the measurement result of the voltage sensor 17 to the collection device 151 (step S203).

On the other hand, when the output current of a predetermined value or more is measured in the stop state of the PCS 8 (NO in step S201 and YES in step S204), the monitoring device 111 measures the measurement unit 19 and the aggregation unit in the corresponding output line 1 It is determined that there is an abnormality in the short circuit between positive and negative electrodes 91 (step S205).

On the other hand, when the reverse current is not measured in the stop state of the PCS 8 (NO in step S201) and the current less than the predetermined value is measured (NO in step S204), the monitoring device 111 detects the corresponding circuit of the output line 1 Is determined to be normal (step S206).

Next, when the monitoring device 111 has not performed abnormality determination on the measurement result of the other power generation unit 78 (NO in step S207), the monitoring apparatus 111 performs abnormality determination on the measurement result of the other power generation unit 78 (step S201).

On the other hand, when the monitoring device 111 performs abnormality determination on the measurement results of all the power generation units 78 (YES in step S207), the abnormality determination in the PCS stop state ends.

FIG. 17 is a flowchart defining an operation procedure when the monitoring apparatus according to the embodiment of the present invention performs abnormality determination in the operating state of the PCS.

Referring to FIG. 17, first, monitoring device 111 starts an abnormality determination for a certain power generation unit 78. When the output current of less than a predetermined value is measured in the operating state of the PCS 8 (YES in step S301), the monitoring device 111 detects a short circuit between the positive and negative electrodes between the power generation unit 78 and the measurement unit 19 in the corresponding output line 1. (Step S302).

Next, the monitoring device 111 transmits the monitoring information including the determination result, the string current data, and the measurement result of the voltage sensor 17 to the collection device 151 (step S303).

On the other hand, in the operating state of the PCS 8, the monitoring device 111 measures an output current greater than or equal to a predetermined value (NO in step S301) and measures an output current that is greater than a predetermined value compared to other string current data. (YES in step S304), it is determined that there is an abnormality in the short circuit between the positive and negative electrodes between the measurement unit 19 and the aggregation unit 91 in the corresponding output line 1 (step S305).

On the other hand, in the operating state of the PCS 8, the monitoring device 111 measures a current that is equal to or greater than a predetermined output value (NO in step S301) and measures an output current that is less than a predetermined value compared to other string current data. (NO in step S304), it is determined that the corresponding circuit of the output line 1 is normal (step S306).

Next, when the monitoring device 111 has not performed abnormality determination on the measurement result of the other power generation unit 78 (NO in step S307), the monitoring apparatus 111 performs abnormality determination on the measurement result of the other power generation unit 78 (step S301).

On the other hand, if the monitoring device 111 performs abnormality determination on the measurement results of all the power generation units 78 (YES in step S307), the abnormality determination in the operating state of the PCS ends.

In the power generation state determination system according to the embodiment of the present invention, the PCS 8 is configured to stop power conversion when operable power is not supplied from the power generation unit 78. However, the present invention is not limited to this. Absent. For example, the PCS 8 may be configured to stop power conversion when the power generation unit 78 generates power exceeding the PCS 8 conversion capacity or when output to the system is suppressed.

In the power generation state determination system according to the embodiment of the present invention, the monitoring device 111 is configured to determine abnormality, but the present invention is not limited to this. The monitoring device 111 transmits each measurement result, the current sensor ID and the voltage sensor ID to the collection device 151 or the management device 101, and the collection device 151 or the management device 101 is based on each measurement result transmitted from the monitoring device 111. It may be configured to determine abnormality. In this case, the management device 101 includes an acquisition unit that acquires each measurement result transmitted from the monitoring device 111, and a determination unit that performs abnormality determinations 1 to 4 based on each measurement result acquired by the acquisition unit.

In the power generation state determination system according to the embodiment of the present invention, the monitoring device 111 is configured to perform the abnormality determinations 1 to 4, but the present invention is not limited to this. The monitoring device 111 may be configured to perform part of the abnormality determinations 1 to 4.

In the power generation state determination system according to the embodiment of the present invention, the monitoring device 111 is configured to include the measurement unit 19, but the present invention is not limited to this. The measurement unit 19 may be configured to be provided outside the monitoring device 111.

In the solar power generation system according to the embodiment of the present invention, the backflow prevention diode 94 is provided for each power generation unit 78, but the present invention is not limited to this. The solar power generation system 401 may have a configuration in which some or all of the

backflow prevention diodes

94A, 94B, 94C, and 94D are not provided.

In the power generation state determination system according to the embodiment of the present invention, the current sensor 16 is provided for each power generation unit 78, but the present invention is not limited to this. The power generation state determination system 301 may have a configuration in which some of the current sensors 16 are not provided. However, the monitoring device 111 performs the abnormality determination 4 when the plurality of current sensors 16 are provided in the corresponding power generation unit 78.

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

In the monitoring apparatus according to the embodiment of the present invention, the acquisition unit 11 acquires the current measurement result of the power generation unit 78 including the solar cell panel 79. The determination unit 15 determines the operating state of the PCS 8 based on the measurement result, and determines an abnormality based on the determined operating state and the measurement result.

With such a configuration, the operation state of the PCS 8 is determined using the current measurement result of the power generation unit 78, and abnormality determination using the current measurement result of the power generation unit 78 is performed according to the determination result. be able to. Thereby, the abnormality in the solar power generation system 401 can be determined satisfactorily.

Therefore, in the monitoring apparatus according to the embodiment of the present invention, the abnormality determination of the solar power generation system 401 can be improved.

In the monitoring device according to the embodiment of the present invention, the determination unit 15 determines that the operating state of the PCS 8 is a stopped state, and determines an abnormality based on the measurement result in the stopped state.

Thus, paying attention to the current measurement result of the power generation unit 78 in the stop state of the PCS 8, the configuration in which the abnormality is determined using the measurement result of the output current of the power generation unit 78 improves the abnormality in the solar power generation system 401. Can be determined.

In the power generation state determination system according to the embodiment of the present invention, the measurement unit 19 that measures the current of the power generation unit 78 is connected between the power generation unit 78 and the PCS 8, and in the monitoring device 111, the determination unit 15 is Based on the measurement result indicating the output current of the power generation unit 78, the abnormality of the circuit between the measurement unit 19 and the PCS 8 is determined.

With such a configuration, it is possible to satisfactorily determine a circuit abnormality between the measurement unit 19 and the PCS 8 using the measurement result of the output current of the power generation unit 78.

Further, in the power generation state determination system according to the embodiment of the present invention, in the solar power generation system 401, output lines from the plurality of power generation units 78 are aggregated in the aggregation unit 91 and electrically connected to the PCS 8 to prevent backflow. The diode 94 is connected between a part or all of the power generation units 78 and the aggregation unit 91 among the plurality of power generation units 78, and the measurement unit 19 that measures the current of the corresponding power generation unit 78 includes the part. Alternatively, all the power generation units 78 and the corresponding backflow prevention diodes 94 are connected, and in the monitoring device 111, the determination unit 15 is based on the measurement result indicating the backflow current to the part or all of the power generation units 78. The abnormality of the backflow prevention diode 94 is determined.

With such a configuration, it is possible to satisfactorily determine the abnormality of the backflow prevention diode 94 using the measurement result of the backflow current to the power generation unit 78.

In the power generation state determination system according to the embodiment of the present invention, the measurement unit 19 that measures the current of the power generation unit 78 is connected between the power generation unit 78 and the PCS 8, and in the monitoring device 111, the determination unit 15 is Then, it is determined that the operating state of the PCS 8 is the operating state, and the abnormality of the circuit between the power generating unit 78 and the measuring unit 19 is determined based on the measurement result indicating the output current of the power generating unit 78 in the operating state of the PCS 8.

Thus, paying attention to the measurement result of the current of the power generation unit 78 in the operating state of the PCS 8, the circuit between the power generation unit 78 and the measurement unit 19 is configured to determine abnormality using the measurement result of the output current of the power generation unit 78. Can be determined satisfactorily.

Further, in the power generation state determination system according to the embodiment of the present invention, in the solar power generation system 401, output lines from the plurality of power generation units 78 are aggregated in the aggregation unit 91 and electrically connected to the PCS 8 for handling. The measuring unit 19 that measures the current of the power generation unit 78 is connected between some or all of the plurality of power generation units 78 and the PCS 8, and in the monitoring device 111, the determination unit 15 is The abnormality of the circuit between the measurement unit 19 and the aggregation unit 91 is determined based on the measurement result indicating the output current of the plurality of power generation units 78 in the operating state of the PCS 8.

Thus, paying attention to the current measurement result of the power generation unit 78 in the operating state of the PCS 8, the configuration in which the abnormality is determined using the measurement result of the output current of each power generation unit 78, between the measurement unit 19 and the aggregation unit 91. A circuit abnormality can be determined satisfactorily.

In the determination method in the monitoring apparatus according to the embodiment of the present invention, first, the current measurement result of the power generation unit 78 is acquired. Next, the operating state of the PCS 8 is determined based on the measurement result. Next, abnormality is determined based on the determined operation state and the measurement result.

Therefore, in the determination method in the monitoring apparatus according to the embodiment of the present invention, the abnormality determination of the solar power generation system 401 can be improved.

It should be considered that the above embodiment is illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

The above description includes the following features.
[Appendix 1]
A monitoring device used in a photovoltaic power generation system in which an output line from a power generation unit including a solar battery panel is electrically connected to a power conversion device,
An acquisition unit for acquiring a current measurement result of the power generation unit;
A determination unit that determines an abnormality based on the measurement result in a stopped state of the power converter,
The power generation unit is a monitoring device that is a string in which a plurality of solar cell panels are connected in series.

1

Output line

2, 4, 5 Aggregation line 3 Internal line 6 Cubicle 7 Copper bar 8 PCS
DESCRIPTION OF SYMBOLS 9 Power conversion part 11 Acquisition part 14 Communication part 15 Determination part 16 Current sensor 17 Voltage sensor 18 Memory | storage part 19 Measurement part 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 Junction box 78 Power generation unit 79 Solar panel 80 PCS unit 81 Determination unit 84 Communication processing unit 85 Storage unit 86 Acquisition unit 91 Aggregation unit 92 Measurement unit 93 Switch 94 Backflow prevention diode 101 Management device 111 Monitoring device 151 Collection device 301 Power generation State determination system 401 Photovoltaic power generation system

Claims

A monitoring device used in a photovoltaic power generation system in which an output line from a power generation unit including a solar battery panel is electrically connected to a power conversion device,
An acquisition unit for acquiring a current measurement result of the power generation unit;
A monitoring device comprising: an operating state of the power converter based on the measurement result; and a determination unit that determines the abnormality based on the determined operating state and the measurement result.
The monitoring device according to claim 1, wherein the determination unit determines that the operation state of the power conversion device is a stopped state, and determines an abnormality based on the measurement result in the stopped state.
A measuring unit that measures the current of the power generation unit is connected between the power generation unit and the power converter,
The monitoring device according to claim 2, wherein the determination unit determines an abnormality in a circuit between the measurement unit and the power converter based on the measurement result indicating the output current of the power generation unit.
In the solar power generation system, output lines from the plurality of power generation units are aggregated in an aggregation unit and electrically connected to the power conversion device,
A backflow prevention diode is connected between a part or all of the power generation units and the aggregation unit among the plurality of power generation units,
A measuring unit for measuring the current of the corresponding power generation unit is connected between the part or all of the power generation unit and the corresponding backflow prevention diode;
The monitoring device according to claim 2, wherein the determination unit determines an abnormality of the backflow prevention diode based on the measurement result indicating a backflow current to the part or all of the power generation units.
A measuring unit that measures the current of the power generation unit is connected between the power generation unit and the power converter,
The determination unit determines that the operation state of the power conversion device is an operation state, and based on the measurement result indicating the output current of the power generation unit in the operation state of the power conversion device, the power generation unit and the measurement The monitoring device according to claim 1, wherein an abnormality of a circuit between the units is determined.
In the solar power generation system, output lines from the plurality of power generation units are aggregated in an aggregation unit and electrically connected to the power conversion device,
A measuring unit that measures the current of the corresponding power generation unit is connected between a part or all of the plurality of power generation units and the power converter among the plurality of power generation units,
The determination unit determines an abnormality in a circuit between the measurement unit and the aggregation unit based on the measurement result indicating output currents of the some or all of the plurality of power generation units in the operating state of the power conversion device. The monitoring device according to claim 5.
A determination method in a monitoring device used in a photovoltaic power generation system in which an output line from a power generation unit including a solar battery panel is electrically connected to a power conversion device,
Obtaining a current measurement result of the power generation unit;
Determining the operating state of the power converter based on the measurement results;
Determining the abnormality based on the determined operating state and the measurement result.