JP6753297B2 - Monitoring device - Google Patents

Description

The present invention relates to a monitoring device.

In recent years, techniques for detecting failures in photovoltaic power generation systems have been developed. For example, Japanese Patent Application Laid-Open 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.

Japanese Unexamined Patent Publication No. 2012-205878

In the photovoltaic power generation monitoring system described in Patent Document 1 as described above, sensors corresponding to each of a plurality of solar cell panels are provided, and each sensor measures the current and the like output from the corresponding solar cell panels. Monitors the photovoltaic power generation system. There is a demand for a technique capable of further reducing the power consumption of such a monitoring device.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a monitoring device capable of further reducing power consumption in a configuration for monitoring a photovoltaic power generation system using a plurality of sensors. Is to provide.

(1) In order to solve the above problems, the monitoring device according to a certain aspect of the present invention is provided to a plurality of sensors for measuring a plurality of solar cell panels, a power supply circuit for supplying power, and the plurality of sensors. A first switching circuit capable of switching the presence or absence of power supply from the power supply circuit, and the plurality of sensors are assigned different measurement periods in a predetermined measurement cycle, and the power supply circuit of the sensor is assigned a different measurement period. It includes a control unit that controls the first switching circuit so that electric power is selectively supplied.

The present invention can be realized not only as a monitoring device provided with such a characteristic processing unit, but also as a monitoring method in which the characteristic processing is a step, or for causing a computer to execute such a step. It can be realized as a program. Further, it can be realized as a semiconductor integrated circuit that realizes a part or all of the monitoring device, or can be realized as a system including the monitoring device.

According to the present invention, power consumption can be further reduced in a configuration in which a plurality of sensors are used to monitor 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 current collector unit according to an embodiment of the present invention. FIG. 3 is a diagram showing a configuration of a solar cell unit according to an embodiment of the present invention. FIG. 4 is a diagram showing a configuration of a monitoring system according to an embodiment of the present invention. FIG. 5 is a diagram showing a configuration of a monitoring device according to an embodiment of the present invention. FIG. 6 is a diagram showing in detail the configuration of the monitoring device according to the embodiment of the present invention. FIG. 7 is a diagram showing power consumption due to measurement of each sensor and output of measurement signals in the monitoring device according to the embodiment of the present invention. FIG. 8 is a diagram showing power consumption due to measurement of each sensor and output of measurement signals in the monitoring device according to the embodiment of the present invention, and power consumption due to transmission of measurement information. FIG. 9 is a diagram showing the power consumption of each of the plurality of monitoring devices in the monitoring system according to the embodiment of the present invention.

First, the contents of the embodiments of the present invention will be listed and described.

(1) The monitoring device according to the embodiment of the present invention includes a plurality of sensors for measuring a plurality of solar cell panels, a power supply circuit for supplying power, and power from the power supply circuit to the plurality of sensors. A first switching circuit capable of switching the presence or absence of supply and the plurality of sensors are assigned different measurement periods in a predetermined measurement cycle, and power from the power supply circuit is selectively supplied during the measurement period of the sensor. A control unit that controls the first switching circuit is provided.

With such a configuration, a plurality of sensors perform time-division measurement within the measurement cycle, and power is supplied to each sensor only during the corresponding measurement period. Therefore, compared with the case where a plurality of sensors constantly perform measurement. Therefore, the power consumption in the monitoring device can be reduced. Therefore, in a configuration in which a plurality of sensors are used to monitor the photovoltaic power generation system, the power consumption can be further reduced.

(2) Preferably, the monitoring device further supplies a processing unit that receives a measurement signal indicating a measurement result by the sensor and processes the measurement signal, and a processing unit that processes the measurement signal from the plurality of sensors. The control unit includes a second switching circuit capable of switching the presence or absence of output, and the control unit selectively outputs the measurement signal from the sensor to the processing unit during the measurement period of the sensor. Control the switching circuit.

With such a configuration, measurement signals from a plurality of sensors are output to the processing unit at different timings, so that the configuration of the processing unit can be simplified.

(3) Preferably, the monitoring device further includes a communication unit that transmits measurement information based on the measurement result by the sensor via a power line, and a plurality of the monitoring devices are connected to the power line. The control unit controls the transmission timing of the measurement information by the communication unit in its own monitoring device so that the transmission timing of the measurement information by the plurality of monitoring devices is different from each other.

With such a configuration, it is possible to prevent interference between signals transmitted from a plurality of monitoring devices that transmit information via the same power line.

(4) More preferably, the control unit controls the transmission timing of the measurement information by the communication unit in its own monitoring device so that the transmission timing of the measurement information by the communication unit does not overlap with the measurement period. To do.

With such a configuration, it is possible to prevent the measurement period by the sensor from overlapping with the transmission timing of the measurement information and to lower the peak value of the power consumption, so that the increase in the capacity of the power supply circuit can be suppressed and the monitoring device can be downsized. can do.

(5) Preferably, the monitoring device further includes a communication unit that transmits measurement information based on the measurement result of the sensor, and the communication unit performs the measurement in a predetermined reporting cycle including a plurality of the measurement cycles. Information is transmitted, and the measurement information indicates the average of the measurement results in each measurement cycle included in the report cycle.

The amount of power generated by the solar cell panel may change temporarily due to the influence of the amount of solar radiation, etc., but as described above, the configuration that averages the measurement results of each of the multiple measurement cycles, for example, Even if there is a temporary change in the amount of power generation, it is possible to prevent an erroneous determination that one solar cell panel is abnormal as compared with the other solar cell panels.

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

<Configuration of 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.

With reference to FIG. 1, the photovoltaic power generation system 401 includes four current collecting units 60 and a PCS 8. The PCS 8 includes a copper bar 7 and a power conversion unit 9.

Although four current collecting units 60 are typically shown in FIG. 1, a large number or a small number of current collecting units 60 may be provided.

FIG. 2 is a diagram showing a configuration of a current collector unit according to an embodiment of the present invention. With reference to FIG. 2, the current collecting unit 60 includes four solar cell units 75 and a copper bar 72.

Although four solar cell units 75 are typically shown in FIG. 2, a large number or a small number of solar cell units 75 may be provided.

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

With reference to FIG. 3, the solar cell unit 75 includes three solar cell panels 78 and a copper bar 77.

Although three solar cell panels 78 are typically shown in FIG. 3, a larger number or a smaller number of solar cell panels 78 may be provided.

The solar cell panel 78 is, for example, a string in which a plurality of solar cell panels are connected in series. The solar cell panel 78 is not limited to the configuration including a plurality of solar cell panels, and may be configured to include one solar cell panel.

In the photovoltaic power generation system 401, output lines 1, 5, and 2, that is, power lines from the plurality of solar cell panels 78 are electrically connected to the PCS 8.

More specifically, the output line 1 of the solar cell panel 78 has a first end connected to the solar cell panel 78 and a second end connected to the copper bar 77. Each output line 1 is integrated into the output line 5 via the copper bar 77. The copper bar 77 is provided inside, for example, a junction box 76, which is an example of a housing.

When the solar panel 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. 2 and 3, the output line 5 has a first end connected to the copper bar 77 in the corresponding solar cell unit 75 and a second end connected to the copper bar 72. Each output line 5 is integrated into the output line 2 via the copper bar 72. The copper bar 72 is provided inside, for example, a current collector box 71, which is an example of a housing.

With reference to FIG. 1 again, in the photovoltaic power generation system 401, as described above, each output line 1 from the plurality of solar cell panels 78 is integrated into the output line 5, and each output line 5 is integrated into the output line 2. , Each output line 2 is electrically connected to a PCS 8 which is an example of a power conversion device.

More specifically, each output line 2 has a first end connected to a copper bar 72 in the corresponding current collector 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.

The PCS 8 is provided inside the container 6, for example. In the PCS 8, for example, the power conversion unit 9 transfers the DC power generated in each solar panel 78 to the output line 1, the copper bar 77, the output line 5, the copper bar 72, the output line 2, the copper bar 7, and the internal line 3. When it is received via, the received DC power is converted to AC power and output to the grid.

<Monitoring system configuration>
FIG. 4 is a diagram showing a configuration of a monitoring system according to an embodiment of the present invention.

With reference to FIG. 4, the monitoring system 301 includes four monitoring devices 111 and a collecting device 101.

In FIG. 4, four monitoring devices 111 provided corresponding to one current collecting unit 60 are typically shown, but a larger number or a smaller number of monitoring devices 111 may be provided. Further, although the monitoring system 301 includes one collecting device 101, a plurality of collecting devices 101 may be provided.

The monitoring system 301 is used for the photovoltaic power generation system 401. In the monitoring system 301, the information of the sensor in the monitoring device 111, which is a slave unit, is periodically or irregularly transmitted to the collecting device 101, which is a master unit.

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 75. Each monitoring device 111 is electrically connected to, for example, the corresponding output line 5.

The monitoring device 111 measures the current of each output line 1 in the corresponding solar cell unit 75 by a sensor. Further, the monitoring device 111 measures the voltage of the output line 5 in the corresponding solar cell unit 75 by a sensor.

The collecting device 101 is provided, for example, in the vicinity of the PCS 8. More specifically, the collector 101 is provided, for example, inside the container 6 corresponding to the PCS 8 and is electrically connected to the copper bar 7 via the signal line 46. The collecting device 101 may be provided outside the container 6.

The monitoring device 111 and the collecting device 101 transmit and receive information by performing power line communication (PLC) via the output lines 2 and 5.

More specifically, each monitoring device 111 transmits measurement information based on the current and voltage measurement results of the corresponding output lines. The collection device 101 collects the measurement results of each monitoring device 111, and notifies the server 151 of the collected measurement results.

<Configuration of monitoring device>
[overall structure]
FIG. 5 is a diagram showing a configuration of a monitoring device according to an embodiment of the present invention. In FIG. 5, the output line 1, the output line 5, the copper bar 77 and the copper bar 72 are shown in more detail.

With reference to FIG. 5, the output line 1 includes a plus side output line 1p and a minus side output line 1n. The output line 5 includes a plus side output line 5p and a minus side output line 5n.

The copper bar 77 includes a positive side copper bar 77p and a negative side copper bar 77n. The copper bar 72 includes a positive side copper bar 72p and a negative side copper bar 72n corresponding to the positive side output line 5p and the negative side output line 5n, respectively.

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

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

The monitoring device 111 includes a detection unit (processing unit) 11, three 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, inside 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 positive side output line 5p and the negative side output line 5n via the positive side power supply line 26p and the negative side power supply line 26n, respectively.

FIG. 6 is a diagram showing in detail the configuration of the monitoring device according to the embodiment of the present invention.

With reference to FIG. 6, the monitoring device 111 includes a control unit 12, a counter 13, a storage unit 15, and a DC, in addition to the detection unit 11, the three current sensors 16, the voltage sensor 17, and the communication unit 14. It includes a / DC converter (power supply circuit) 19, a first switching circuit SW1, and a second switching circuit SW2.

Each circuit in the monitoring device 111 operates by using the output voltage of the solar cell panel 78 supplied from the output line 5 as the power supply voltage.

More specifically, the DC / DC converter 19 boosts or boosts the DC voltage of the solar panel 78 that receives from the negative side output line 5n and the positive side output line 5p via the negative side power supply line 26n and the positive side power supply line 26p, respectively. The voltage is stepped down to generate a DC voltage Vc. Then, the DC / DC converter 19 outputs the generated DC voltage Vc to each circuit in the monitoring device 111.

[Measurement by sensor]
With reference to FIG. 6, the three current sensors 16 measure the current of the output line 1 corresponding to each of the plurality of solar cell panels 78. 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, and outputs a measurement signal indicating the measurement result to the detection 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 5. More specifically, the voltage sensor 17 measures the voltage between the positive power supply line 26p and the negative power supply line 26n, and outputs a measurement signal indicating the measurement result to the detection unit 11.

The three current sensors 16 measure the current and output a measurement signal indicating the measurement result in a time-division manner, for example, in a predetermined measurement period TC. Further, the voltage sensor 17 measures the voltage and outputs a measurement signal indicating the measurement result, for example, during a period in which the measurement by the current sensor 16 is not performed. Hereinafter, each of the three current sensors 16 and the voltage sensor 17 is also simply referred to as a “sensor”.

More specifically, the first switching circuit SW1 is connected between the DC / DC converter 19 and each sensor. The first switching circuit SW1 sets the power supply destination from the DC / DC converter 19, that is, the output destination of the DC voltage Vc to any one of a plurality of sensors according to the first control signal output from the control unit 12, for example. Selectively switch to one.

The second switching circuit SW2 is connected between each sensor and the detection unit 11, and for example, according to the second control signal output from the control unit 12, the connection destination of the detection unit 11 is among the plurality of sensors. Selectively switch to any one.

In the storage unit 15, for example, period information indicating the reference time ts, the length LC of the measurement period TC, and the length LA of the measurement cycle TA including the measurement period TC is stored. The reference time ts is, for example, 0 o'clock.

The length LA of the measurement cycle TA is set longer than the length LC of the measurement period TC. That is, in the measurement cycle TA, a period during which the measurement by the sensor is not performed (hereinafter, also referred to as “free period ST”) is provided. Further, the measurement period TC is repeated in the LA cycle.

The counter 13 counts clock pulses generated by, for example, an oscillation circuit using a crystal oscillator, and holds the counted values. This count value indicates, for example, the current time.

For example, the control unit 12 divides the measurement period TC into four periods TC1, TC2, TC3, TC4, and assigns the periods TC1, TC2, TC3, TC4 to the three current sensors 16 and the voltage sensor 17, respectively.

Specifically, it is assumed that the monitoring device 111 includes current sensors 16A, 16B, 16C as the above-mentioned three current sensors 16. Further, it is assumed that the control unit 12 assigns the period TC1 to the current sensor 16A, assigns the period TC2 to the current sensor 16B, assigns the period TC3 to the current sensor 16C, and assigns the period TC4 to the voltage sensor 17.

Further, the control unit 12 calculates the start timing of the measurement period TC, for example, based on the period information stored in the storage unit 15. As described above, since the measurement period TC is repeated in the LA cycle, for example, the start timing of the measurement period TC is ts + LA × K. Here, K is an integer greater than or equal to zero.

Further, the control unit 12 calculates the start timing of each of the periods TC1, TC2, TC3, and TC4 assigned to each sensor.

For example, the storage unit 15 stores information indicating the respective lengths LC1, LC2, LC3, LC4 of the periods TC1, TC2, TC3, and TC4, and the control unit 12 stores the information in the storage unit 15. With reference to the information, the start timing of each of the periods TC1, TC2, TC3, and TC4 is calculated.

Specifically, it is assumed that the current sensor 16A, the current sensor 16B, the current sensor 16C, and the voltage sensor 17 perform measurement and output of the measurement signal in this order during the measurement period TC. Further, it is assumed that the start timing of the period TC1 assigned to the current sensor 16A is ts + LA × K, which is the same as the start timing of the measurement period TC.

In this case, the start timing of the period TC2 assigned to the current sensor 16B is, for example, ts + LA × K + LC1. Further, the start timing of the period TC3 assigned to the current sensor 16C is, for example, ts + LA × K + LC2. Further, the start timing of the period TC4 assigned to the voltage sensor 17 is, for example, ts + LA × K + LC3.

Then, the control unit 12 monitors the counter value in the counter 13, for example, and outputs the first control signal and the second control signal so that the corresponding sensor outputs the measurement and the measurement signal in each assigned period. Output.

The first switching circuit SW1 switches the power supply destination to the current sensor 16A at the start timing of the period TC1 according to the first control signal received from the control unit 12, and switches the power supply destination to the current sensor 16B at the start timing of the period TC2. At the start timing of the period TC3, the power supply destination is switched to the current sensor 16C, and at the start timing of the period TC4, the power supply destination is switched to the voltage sensor 17.

The second switching circuit SW2 switches the connection destination of the detection unit 11 to the current sensor 16A at the start timing of the period TC1 according to the second control signal received from the control unit 12, and the connection destination of the detection unit 11 at the start timing of the period TC2. Is switched to the current sensor 16B, the connection destination of the detection unit 11 is switched to the current sensor 16C at the start timing of the period TC3, and the connection destination of the detection unit 11 is switched to the voltage sensor 17 at the start timing of the period TC4.

FIG. 7 is a diagram showing power consumption due to measurement of each sensor and output of measurement signals in the monitoring device according to the embodiment of the present invention.

With reference to FIG. 7, the current sensor 16A measures the current and outputs the measurement signal during the period TC1, the current sensor 16B measures the current and outputs the measurement signal during the period TC2, and the current sensor 16C outputs the measurement signal during the period TC3. The current is measured and the measurement signal is output, and the voltage sensor 17 measures the voltage and outputs the measurement signal during the period TC4. Then, the measurement period TC in which such an operation is performed is repeated in the measurement cycle TA.

It should be noted that the measurement and the output of the measurement signal by each sensor do not have to be periodic, and each sensor may output the measurement and the measurement signal at different timings included in one measurement period TC.

Further, in the monitoring device 111, if the plurality of current sensors 16 are configured to measure the current and output the measurement signals in a time-division manner, the voltage sensor 17 is configured to constantly measure the voltage and output the measurement signals. You may.

Further, the monitoring device 111 is not limited to the configuration including both the current sensor 16 and the voltage sensor 17, and may be configured to include either the current sensor 16 or the voltage sensor 17.

[Send measurement information]
With reference to FIG. 6 again, the detection unit 11 holds the measurement signals received from the plurality of current sensors 16 and the voltage sensors 17. Then, for example, the detection unit 11 performs signal processing on these measurement signals in a predetermined reporting cycle TB, and outputs the data after the signal processing to the control unit 12.

More specifically, the period information stored in the storage unit 15 includes the reference time ts, the measurement period TC length LC, and the measurement cycle TA length LA, as well as the reporting cycle TB length LB. Is shown. One reporting cycle TB includes a plurality of measurement cycles TA.

The control unit 12 calculates the start timing of each reporting cycle TB based on the period information stored in the storage unit 15. For example, the start timing of each reporting cycle TB is ts + LB × K. Here, K is an integer greater than or equal to zero.

Then, the control unit 12 monitors the counter value in the counter 13 and requests the detection unit 11 to output the measurement signal at the start timing of each calculated report cycle TB.

Upon receiving the output request of the measurement signal from the control unit 12, the detection unit 11 processes, for example, the measurement signal indicating the value measured in the report cycle TB immediately before the report cycle TB including the current time. The processed data is output to the control unit 12.

More specifically, the detection unit 11 calculates, for example, the average value of the current or voltage measured in each of the plurality of measurement period TCs included in the reporting cycle TB for each sensor. That is, the detection unit 11 averages the values indicated by the plurality of measurement signals received from the sensor during the period from the timing when the output request is received from the control unit 12 to the timing when the output request is next received from the control unit 12. The value is calculated for each sensor.

In addition, the detection unit 11 performs signal processing such as filtering on the signal indicating the calculated average value. Further, the detection unit 11 includes, for example, an AD converter, converts the signal after signal processing into a digital signal, and outputs the converted digital signal to the control unit 12.

The detection unit 11 performs signal processing as described above for each measurement signal from the plurality of current sensors 16 and the voltage sensor 17, and outputs the digital signal after the signal processing to the control unit 12.

The control unit 12 has a plurality of measurement results indicated by digital signals received from the detection unit 11, an ID of the current sensor 16 corresponding to each measurement result, an ID of the voltage sensor 17 corresponding to the measurement result, and a self-monitoring device 111. Create measurement information including ID.

Then, the control unit 12 outputs the created measurement information to the communication unit 14. When the communication unit 14 receives the measurement information from the control unit 12, the communication unit 14 transmits the measurement information to the collection device 101 by power line communication via the output lines 5 and 2 and the signal line 46.

The control unit 12 may be configured to create measurement information for each sensor and transmit the created measurement information for each sensor to the collection device 101 via the communication unit 14.

Here, the control unit 12 controls so that the transmission timing of the measurement information from the communication unit 14 does not overlap with the measurement period TC. That is, the control unit 12 controls so that the measurement information is transmitted during the free period ST.

For example, the period information stored in the storage unit 15 includes the reference time ts, the measurement period TC length LC, the measurement cycle TA length LA, and the reporting cycle TB length LB, as well as the transmission waiting time. Indicates Lx. The transmission standby time Lx is set to be longer than, for example, the measurement period TC and shorter than the reporting cycle TB.

For example, the control unit 12 calculates the start timing of each report cycle TB based on the period information stored in the storage unit 15, and the timing at which the transmission standby time Lx elapses from the calculated start timing of each report cycle TB. Is determined as the transmission timing of the measurement information.

Then, for example, the control unit 12 confirms whether or not the determined transmission timing is included in the measurement period TC, and if the transmission timing is not included in the measurement period TC, the control unit 12 measures at the transmission timing via the communication unit 14. Information is transmitted to the collecting device 101.

When the transmission timing is included in the measurement period TC, the control unit 12 transmits the measurement information to the collection device 101 via the communication unit 14, for example, after the measurement period TC has elapsed or before the measurement period TC has started. To do.

FIG. 8 is a diagram showing power consumption due to measurement of each sensor and output of measurement signals in the monitoring device according to the embodiment of the present invention, and power consumption due to transmission of measurement information.

With reference to FIG. 8, specifically, it is assumed that a certain reporting cycle TB is a period of time t1 to time t2, and the next reporting cycle TB is a period of time t2 to time t3.

In this case, the detection unit 11 in the monitoring device 111 performs signal processing on each measurement signal received from the plurality of current sensors 16 and the voltage sensors 17 during the period from time t1 to time t2, for example, at the timing after time t2. The data after signal processing is output to the control unit 12.

Then, the control unit 12 creates measurement information based on the data received from the detection unit 11, and transmits the measurement information to the collection device 101 at the time tx, which is the timing when the transmission standby time Lx has elapsed from the time t2. Do.

By performing the above operation, the power consumption in the monitoring device 111 increases at the timing when the measurement by each sensor and the output of the measurement signal are performed, and the timing when the measurement information is transmitted to the collecting device 101. ..

[Details of measurement information transmission timing]
With reference to FIG. 4 again, the plurality of monitoring devices 111 in the monitoring system 301 are all connected to the same output line 2, and the measurement information is transmitted by performing power line communication via the output line 2. Therefore, the transmission timings of the measurement information from each monitoring device 111 are set so as not to overlap each other.

As described above, in the measurement cycle TA, a free period ST in which the current sensor 16 does not measure is provided. That is, there are a plurality of free period STs in the reporting cycle TB including the plurality of measurement cycle TAs. Therefore, for example, by assigning a plurality of free period STs in the reporting cycle TB to different monitoring devices 111, it is possible to distribute the transmission timing of the measurement information from each monitoring device 111 within the same reporting cycle TB.

FIG. 9 is a diagram showing the power consumption of each of the plurality of monitoring devices in the monitoring system according to the embodiment of the present invention. FIG. 9 shows the total power consumption of each of the three monitoring devices 111.

With reference to FIG. 9, the monitoring system 301 includes, for example, monitoring devices 111A, 111B, 111C as three monitoring devices 111. The transmission standby time Lx having different values is set in each monitoring device 111.

Specifically, for example, the monitoring device 111A is set with a transmission standby time LxA that is longer than the measurement period TC and shorter than the measurement cycle TA. Further, for example, the monitoring device 111B is set with a transmission standby time LxB that is longer than the transmission standby time LxA by the length of the measurement cycle TA. Further, for example, the monitoring device 111C is set with a transmission standby time LxC that is longer than the transmission standby time LxB by the length of the measurement cycle TA.

Further, it is assumed that a certain reporting cycle TB is a period of time t1 to time t2, the next reporting cycle TB is a period of time t2 to time t3, and the next reporting cycle TB is a period of time t3 to time t4. To do.

In this case, the monitoring device 111A sends the measurement information indicating the current and voltage measured in the period from time t1 to time t2 to the collecting device 101 at time ta1, which is the timing when the transmission standby time LxA has elapsed from time t2. Send. Further, the monitoring device 111A transmits, for example, measurement information indicating the current and voltage measured in the period from time t2 to time t3 to the collecting device 101 at time ta2, which is the timing when the transmission standby time LxA has elapsed from time t3. To do.

Further, the monitoring device 111B transmits, for example, measurement information indicating the current and voltage measured in the period of time t1 to time t2 to the collecting device 101 at time tb1 which is the timing when the transmission standby time LxB has elapsed from time t2. To do. Further, the monitoring device 111B transmits, for example, measurement information indicating the current and voltage measured in the period from time t2 to time t3 to the collecting device 101 at time tb2, which is the timing when the transmission standby time LxB has elapsed from time t3. To do.

Further, the monitoring device 111C transmits, for example, measurement information indicating the current and voltage measured in the period of time t1 to time t2 to the collecting device 101 at time tc1 which is the timing when the transmission standby time LxC has elapsed from time t2. To do. Further, the monitoring device 111C transmits, for example, measurement information indicating the current and voltage measured in the period from time t2 to time t3 to the collecting device 101 at time tc2, which is the timing when the transmission standby time LxC has elapsed from time t3. To do.

By performing the above operation, the transmission timing of the measurement information from each monitoring device 111 is included in the free period ST and does not overlap with each other.

In the example shown in FIG. 9, the start timing and end timing of each measurement period TC are the same among the plurality of monitoring devices 111, but the start timing and end timing of each measurement period TC are different from each other. It may differ between 111.

Further, in the monitoring device 111 according to the embodiment of the present invention described above, the second switching circuit SW2 switches the connection destination of the detection unit 11 to any one of the plurality of sensors. However, the present invention is not limited to such a configuration, and the monitoring device 111 may be configured not to include the second switching circuit SW2.

Further, the transmission timing of the measurement information from each monitoring device 111 provided in the monitoring system 301 does not necessarily have to be different timing. For example, when a plurality of monitoring devices 111 transmit measurement information via different power lines, the plurality of monitoring devices 111 can transmit measurement information at the same timing.

Further, in the monitoring device 111 according to the embodiment of the present invention described above, the control unit 12 controls so that the measurement information is transmitted during the free period ST. However, the configuration is not limited to such a configuration, and the control unit 12 may be configured to transmit measurement information at a timing included in the measurement period TC.

Further, the measurement information transmitted from the monitoring device 111 according to the embodiment of the present invention described above indicates the average of the values measured in each of the plurality of measurement period TCs included in one reporting cycle TB. However, the measurement information transmitted from the monitoring device 111 is not limited to such a configuration, and is, for example, information indicating the values themselves measured in a plurality of measurement period TCs included in one reporting cycle TB. May be good.

By the way, the monitoring device in the photovoltaic power generation monitoring system described in Patent Document 1 described above includes sensors corresponding to each of a plurality of solar cell panels, and each sensor measures the current and the like output from the corresponding solar cell panels. By doing so, the photovoltaic power generation system is monitored.

Such a monitoring device can operate by using the output voltage from the solar cell panel as the power supply voltage, but since a plurality of sensors each measure the voltage, the power consumption may increase. Further, since the measurement result by each sensor is transmitted to another device by, for example, power line communication, electric power for such transmission is also required.

In particular, when a large number of monitoring devices are provided in the power plant, the power consumption of the entire power plant becomes large. Therefore, there is a demand for a technique capable of further reducing the power consumption of such a monitoring device.

On the other hand, in the monitoring device 111 according to the embodiment of the present invention, the plurality of current sensors 16 and the voltage sensors 17 measure each of the plurality of solar cell panels 78. Further, the DC / DC converter 19 supplies electric power to each circuit in the monitoring device 111. Further, the first switching circuit SW1 can switch whether or not power is supplied from the DC / DC converter 19 to the plurality of current sensors 16 and the voltage sensors 17. Further, the control unit 12 allocates different measurement periods to the plurality of current sensors 16 and the voltage sensors 17 in a predetermined measurement cycle TA, and the power from the DC / DC converter 19 is selectively supplied during the measurement period of the sensors. The first switching circuit SW1 is controlled in this way.

With such a configuration, a plurality of sensors perform time-division measurement within the measurement cycle TA, and power is supplied to each sensor only during the corresponding measurement period. Therefore, compared with the case where a plurality of sensors constantly perform measurement. Therefore, the power consumption in the monitoring device 111 can be reduced. Therefore, the power consumption can be further reduced in the configuration in which the photovoltaic power generation system 401 is monitored by using a plurality of sensors.

Further, the detection unit 11 receives the measurement signal indicating the measurement result by the sensor and processes the measurement signal. Further, the second switching circuit SW2 can switch whether or not the measurement signals from the plurality of sensors are output to the detection unit 11. Further, the control unit 12 controls the second switching circuit SW2 so that the measurement signal from the corresponding sensor is selectively output to the detection unit 11 during the measurement period of the sensor.

With such a configuration, measurement signals from a plurality of sensors are output to the detection unit 11 at different timings, so that the configuration of the detection unit 11 can be simplified.

Further, the communication unit 14 transmits measurement information based on the measurement result by the sensor via the power line. Further, a plurality of monitoring devices 111 are connected to the power line, and the control unit 12 receives the measurement information by the communication unit 14 in its own monitoring device 111 so that the transmission timings of the measurement information by the plurality of monitoring devices 111 are different from each other. Controls the transmission timing of.

With such a configuration, it is possible to prevent interference between signals transmitted from a plurality of monitoring devices 111 that transmit information via the same power line.

Further, the control unit 12 controls the transmission timing of the measurement information by the communication unit 14 in its own monitoring device 111 so that the transmission timing of the measurement information by the communication unit 14 does not overlap with the measurement period TC.

With such a configuration, it is possible to prevent the measurement period by the sensor from overlapping with the transmission timing of the measurement information and to lower the peak value of the power consumption, so that the increase in the capacity of the power supply circuit can be suppressed and the monitoring device 111 can be made smaller. Can be transformed into.

Further, the communication unit 14 transmits measurement information in a predetermined reporting cycle TB including a plurality of measurement cycle TAs. Further, the measurement information indicates the average of the measurement results in each measurement cycle TA included in the reporting cycle TB.

The amount of power generated by the solar cell panel 78 may change significantly temporarily due to the influence of the amount of solar radiation, etc., but as described above, the configuration that averages the measurement results of each of the multiple measurement cycle TAs For example, even if there is a temporary change in the amount of power generation, it is possible to prevent an erroneous determination that one solar cell panel 78 is abnormal as compared with the other solar cell panels 78.

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 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]
Multiple sensors that measure each of multiple solar panels,
A power supply circuit that supplies power and
A first switching circuit capable of switching the presence / absence of power supply from the power supply circuit to the plurality of sensors, and
A control unit that controls the first switching circuit so that different measurement periods are assigned to the plurality of sensors in a predetermined measurement cycle, and power from the power supply circuit is selectively supplied during the measurement period of the sensors. When,
It is provided with a processing unit that receives a measurement signal indicating the measurement result by the sensor and processes the measurement signal.
The sensor is a current sensor and
The processing unit includes an AD converter that converts the measurement signal into a digital signal.
The plurality of sensors are monitoring devices that operate using the output voltage of the solar cell panel supplied from the power supply circuit as a power supply voltage.

1,2,5 Output line 3 Internal line 6 Container 7 Copper bar 8 PCS
9 Power conversion unit 11 Detection unit (processing unit)
12 Control unit 13 Counter 14 Communication unit 15 Storage unit 16 Current sensor 17 Voltage sensor 19 DC / DC converter (power supply circuit)
26 Power line 46 Signal line 60 Current collection unit 71 Current collection box 72 Copper bar 75 Solar cell unit 77 Copper bar 78 Solar cell panel 101 Collection device 111 Monitoring device 151 Server 301 Monitoring system 401 Solar power generation system SW1 First switching circuit SW2 2nd switching circuit

Claims (5)

Multiple sensors that measure each of multiple solar panels,
A power supply circuit that supplies power and
A first switching circuit capable of switching the presence / absence of power supply from the power supply circuit to the plurality of sensors, and
A control unit that controls the first switching circuit so that different measurement periods are assigned to the plurality of sensors in a predetermined measurement cycle, and power from the power supply circuit is selectively supplied during the measurement period of the sensors. A monitoring device equipped with. The monitoring device further
A processing unit that receives a measurement signal indicating the measurement result by the sensor and processes the measurement signal,
A second switching circuit capable of switching the presence / absence of output of the measurement signal from the plurality of sensors to the processing unit is provided.
The monitoring device according to claim 1, wherein the control unit controls the second switching circuit so that the measurement signal from the sensor is selectively output to the processing unit during the measurement period of the sensor. The monitoring device further
It is provided with a communication unit that transmits measurement information based on the measurement results of the sensor via a power line.
A plurality of the monitoring devices are connected to the power line.
The control unit controls the transmission timing of the measurement information by the communication unit in its own monitoring device so that the transmission timing of the measurement information by the plurality of monitoring devices is different from each other. The monitoring device described in. The third aspect of claim 3, wherein the control unit controls the transmission timing of the measurement information by the communication unit in its own monitoring device so that the transmission timing of the measurement information by the communication unit does not overlap with the measurement period. Monitoring device. The monitoring device further
It is equipped with a communication unit that transmits measurement information based on the measurement results of the sensor.
The communication unit transmits the measurement information at a predetermined reporting cycle including the plurality of measurement cycles.
The monitoring device according to any one of claims 1 to 4, wherein the measurement information indicates the average of the measurement results in each measurement cycle included in the reporting cycle.

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