JP2017225303A - Solar cell monitoring system, and solar cell monitoring program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar cell monitoring system capable of discriminating abnormality of a solar cell while mitigating a limitation in operation of the solar cell, and a solar cell monitoring program.SOLUTION: A solar cell monitoring system comprises: a derivation section for deriving a current/voltage property curve relating to an open-circuit voltage value direction from a voltage value which is set while defining operation points that are a current value and a voltage value in a case where an output value of electric power becomes satisfactory, as references based on a current value and a voltage value acquired in electric power outputted from a solar cell acquired by an acquisition section; a first discrimination section for discriminating whether an integrated value that is obtained by integrating the current value in the derived current/voltage property curve from the voltage value that is set with the operation point defined as the reference to an upper limit value is decreased as much as or more than a predetermined value in relative to a reference value; and an output section for outputting information indicating that the solar cell is abnormal, in the case where it is discriminated that the integrated value is decreased as much as or more than the predetermined value.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a solar cell monitoring system and a solar cell monitoring program.

  2. Description of the Related Art Conventionally, a monitoring device that determines an abnormality using a short-circuit current value when a solar cell is in a short-circuit state and an open-circuit voltage value when the solar cell is in an open state is known (for example, Patent Document 1). And 2).

JP 2012-186409 A JP 2013-239629 A

However, when acquiring a short-circuit current value for abnormality determination, it is necessary to set the voltage value output by the solar cell to zero, which may limit the operation of the solar cell.
The present invention has been made in view of the above circumstances, and provides a solar cell monitoring system and a solar cell monitoring program that can relax the limitation of the operation of the solar cell and determine an abnormality of the solar cell. With the goal.

  The solar cell monitoring system of the present embodiment includes an acquisition unit that acquires a current value and a voltage value in power output from a solar cell, and among the current value and voltage value acquired by the acquisition unit, the output value of the power A derivation unit for deriving a current-voltage characteristic curve in the direction of the open-circuit voltage value from a voltage value set with reference to an operating point that is a current value and a voltage value when the current becomes good, and a current voltage derived by the derivation unit First, it is determined whether or not an integrated value obtained by integrating the current value in the characteristic curve between the voltage value set with the operating point as a reference and the upper limit value is decreased by a predetermined value or more compared to the reference value. 1 determination part, and the output part which outputs the information which shows that the said solar cell is abnormal when it determines with the said 1st determination part having decreased more than predetermined value.

  An object of the present invention is to provide a solar cell monitoring system and a solar cell monitoring program that can relax the limitation of the operation of the solar cell and determine an abnormality of the solar cell.

It is a lineblock diagram of solar cell monitoring system 1 of a 1st embodiment. It is a figure which shows the function structure of the connection part 20 and the power converter device 30. FIG. 4 is a flowchart showing a flow of processing executed by the power conversion device 30. It is a figure for demonstrating measured integral value MI. It is a figure which shows the relationship between the decreasing rate of measured integral value MI, and the output decreasing rate of the electric power of the string 12. FIG. FIG. 6 is a diagram illustrating a relationship between a differential value and a voltage value in power output by a string 12; It is a figure which shows an example of the classification determination map. 4 is a diagram illustrating an example of an interface image IM displayed on the display unit 112 of the management apparatus 100. FIG. It is a figure which shows the function structure of 1 A of solar cell monitoring systems of 2nd Embodiment.

  Hereinafter, embodiments of a solar cell monitoring system and a solar cell monitoring program of the present invention will be described with reference to the drawings.

(First embodiment)
(Configuration of solar cell monitoring system)
FIG. 1 is a configuration diagram of a solar cell monitoring system 1 according to the first embodiment. In the illustrated example, the power line and the communication line are shown without being distinguished. The solar cell monitoring system 1 includes power generation units 10-1 to 10-n and a management device 100. “N” is an arbitrary natural number. The power generation units 10-1 to 10-n and the management device 100 communicate with each other via the network NW. The network NW includes a local area network (LAN), a wide area network (WAN), and the like. The network NW may be wired or wireless, or a combination thereof. Hereinafter, when the power generation unit 10-1 and the power generation unit 10-n are not distinguished, they are referred to as “power generation unit 10”.

  Hereinafter, the power generation unit 10-1 will be described as an example. Since the power generation unit 10-n has the same functional configuration as that of the power generation unit 10-1, description thereof is omitted. Moreover, although this embodiment demonstrates as an example that the electric power generation unit 10 is provided in the house, it is not this limitation. The power generation unit 10 may be provided in a factory, an open space, etc. for industrial use, for example.

  The power generation unit 10-1 includes a solar cell module. The solar cell module includes strings 12A-1 to 12A-k connected in parallel. “K” is an arbitrary natural number. String 12A-1 includes power generators 14A-1-1 to 14A-1-n connected in series, respectively. String 12A-2 includes power generators 14A-2-1 to 14A-2-n connected in series. Strings 12A-k include power generators 14A-k-1 to 14A-kn connected in series, respectively. Hereinafter, when the strings 12A-1 to 12A-k are not distinguished, they are referred to as “string 12”. Moreover, when not distinguishing power generation device 14A-k-1 to 14A-kn, it is called "power generation device 14".

  The power generation device 14 is, for example, a solar power generation device. The power generation device 14 is electrically connected to the power conversion device 30 via the connection unit 20. The power generation device 14 converts sunlight energy into DC power, and outputs the converted DC power to the power conversion device 30.

  A HEMS (Home Energy Management System) 50 includes a display unit, an operation unit, a control unit, and the like. The display unit displays, for example, the power generation amount of the power generation device 14 and the power consumption at a predetermined interval (for example, every day, every week, every month) such as an electrical device connected to the HEMS 50. Further, the display unit may display an abnormality determination result for the string 12. The control unit switches the content displayed on the display unit or controls the electric device connected to the HEMS 50 based on the operation of the operation unit by the user.

  The management device 100 includes a communication unit 110 and a display unit 112. The communication unit 110 is a communication interface for communicating with the power generation unit 10. The display unit 112 is a display device such as an LCD (Liquid Crystal Display) or an organic EL (Electro Luminescence). The management device 100 acquires information from the power generation unit 10 and causes the display unit 112 to display the acquired information.

(Configuration of connection unit and power converter)
FIG. 2 is a diagram illustrating a functional configuration of the connection unit 20 and the power conversion device 30. The connection unit 20 includes a detection unit 22 and a connection communication unit 24. The detection unit 22 detects a current value and a voltage value in the power output by the string 12. For example, the detection unit 22 detects a current value and a voltage value in power for each string 12. The connection communication unit 24 is a communication interface for communicating with the power conversion device 30. The connection communication unit 24 transmits information on the current value and the voltage value detected by the detection unit 22 to the power conversion device 30.

  The power conversion device 30 includes a power conversion unit 32, a current voltage acquisition unit 34, a conversion control unit 36, a characteristic derivation unit 38, a first determination unit 40, a second determination unit 42, a type determination unit 44, a storage unit 46, and a communication. Part 50 is provided. Some or all of the conversion control unit 36, the characteristic derivation unit 38, the first determination unit 40, the second determination unit 42, and the type determination unit 44 are executed by a processor such as a CPU (Central Processing Unit). It may be realized. Some or all of these functional units may be realized by hardware such as LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), or FPGA (Field-Programmable Gate Array). The storage unit 46 is realized by a storage device such as a random access memory (RAM), a read only memory (ROM), a hard disk drive (HDD), or a flash memory, for example. The storage unit 46 stores reference data 47 and a type determination map 48 described later.

  The power conversion unit 32 is a PCS (Power Conditioning System). The power conversion unit 32 converts the DC power generated by the power generation device 14 into AC power. The power conversion unit 32 includes, for example, a DC (Direct Current) -DC converter (not shown), an inverter, a gate drive unit, and the like. The DC-DC converter converts the DC power output by the string 12 into DC power having a desired current and voltage, and outputs the DC power to the HEMS 50. The inverter includes a plurality of switching elements. The inverter performs on / off control of the switching element based on the gate control signal output by the gate driver. By this control, the DC power converted by the DC-DC converter is converted to AC power. The gate drive unit generates a gate control signal based on the signal output from the conversion control unit 36.

  The current / voltage acquisition unit 34 acquires the current value and the voltage value detected by the detection unit 22 of the connection unit 20.

The conversion control unit 36 controls the operating state of the power conversion unit 32. The conversion control unit 36 calculates the duty ratio of the switching element based on, for example, a signal input from the characteristic deriving unit 38. The conversion control unit 36 generates a PWM (Pulse Width Modulation) signal based on the calculated duty ratio, and outputs the generated PWM signal.

  The characteristic deriving unit 38 derives an operating point based on the current value and the voltage value acquired by the current / voltage acquiring unit 34. The operation point is, for example, a point for performing maximum power point tracking control (MPPT). For example, the characteristic deriving unit 38 changes the voltage value or the current value of the power output by the string 12 within a predetermined range, and the operating point (current value and voltage value) at which the power output by the string 12 becomes maximum. )

  For example, the characteristic deriving unit 38 derives an operation point using a hill climbing method. The characteristic deriving unit 38 changes the voltage value in one direction (increase or decrease). The characteristic deriving unit 38 controls the direction in which the voltage value is changed in the reverse direction when the power value is changed from the increase to the decrease due to the change in the voltage value. The characteristic deriving unit 38 derives an operating point at which the power value is maximized by repeating the above-described control.

  The characteristic deriving unit 38 derives a current-voltage characteristic curve in the open voltage value direction from the voltage value set with the operating point as a reference. The voltage value set based on the operating point is, for example, a voltage value near the operating point. The vicinity of the operation point is, for example, a point within a predetermined range set with the operation point as a reference. Further, an operation point may be included in the vicinity of the operation point. The voltage value near the operating point is, for example, a voltage value that does not limit the operation of the power generation device 14 (does not lower the output by a predetermined value or more). The open circuit voltage value is the voltage of the string 12 in an unloaded state. For example, the characteristic deriving unit 38 acquires the open circuit voltage value by controlling the output side of the string 12 to a no-load state.

  The first determination unit 40 determines whether or not the integrated value obtained by integrating the current value in the current-voltage characteristic curve from the voltage value near the operating point to the upper limit value is decreased by a predetermined value or more compared to the reference value. Determine. The upper limit value is, for example, an open circuit voltage value.

  The second determination unit 42 determines abnormality of the string 12 based on a change in current value in the current-voltage characteristic curve. The second determination unit derives a differential value obtained by differentiating the power derived based on the current-voltage characteristic curve with a voltage value, and determines the type of abnormality of the string 12 based on the derived differential value.

  The type determination unit 44 determines the abnormality of the string 12 based on the change in the current value corresponding to two voltage values included between the voltage value set on the basis of the operating point in the current-voltage characteristic curve and the open-circuit voltage value. The type of is determined. In addition, the type determination unit 44 differentiates the power corresponding to the first voltage value included between the open-circuit voltage value from the voltage value set with the operating point in the current-voltage characteristic curve as a reference, The type of abnormality is determined based on a differential value obtained by differentiating the power corresponding to the second voltage value included between the open-circuit voltage value and the voltage value set with the operating point as a reference.

  The communication unit 50 transmits the processing content of the characteristic deriving unit 38, the first determination unit 40, the second determination unit 42, or the type determination unit 44 described above to the management apparatus 100.

(Operation of power converter)
FIG. 3 is a flowchart showing a flow of processing executed by the power conversion device 30. This process is executed for each string 12 of interest among the plurality of strings 12. In addition, this process may be performed for every solar cell module to which attention is paid.

  First, the current voltage acquisition unit 34 acquires the current value and voltage value detected by the detection unit 22 (step S100). Next, the characteristic deriving unit 38 acquires the voltage value Vpm and current value Ipm of the operating point based on the acquired current value and voltage value (step S102).

  Next, the characteristic deriving unit 38 changes the voltage value Vpm to acquire the open circuit voltage value Voc (step S104). Next, the characteristic deriving unit 38 acquires a current-voltage characteristic curve PL in a range between the voltage value Vpm and the open circuit voltage value Voc (step S106). For example, the characteristic deriving unit 38 acquires a current value for each change in voltage value. The characteristic deriving unit 38 generates a current-voltage characteristic curve PL based on the changed voltage value and the acquired current value.

  Next, the first determination unit 40 derives an integral value obtained by integrating the current value in the current-voltage characteristic curve PL from the voltage value Vpm to the open-circuit voltage value Voc (hereinafter, measured integral value MI) (step S108). ).

  FIG. 4 is a diagram for explaining the actually measured integral value MI. In the figure, the horizontal axis indicates the voltage value, and the vertical axis indicates the current value. In the figure, the area of the shaded area is the measured integral value MI. In the figure, Isc represents a short-circuit current, and Ipm in the figure is a current value corresponding to the operating point P.

  Next, the first determination unit 40 acquires a reference value from the reference data 47 (step S110). For example, the first determination unit 40 acquires a reference value based on the operation point P. The reference value is an integral value set in advance for the operating point P. For example, the reference value is an integrated value obtained by integrating the current value in the reference current-voltage characteristic curve set for each operation point P from the voltage value to the open-circuit voltage value.

  The reference current-voltage characteristic curve PL is determined by a known method. For example, the reference current-voltage characteristic curve PL may be obtained experimentally, or may be derived based on a current-voltage characteristic curve of a string 12 different from the string 12 of interest included in the power generation unit 10. . Another string 12 is, for example, a string installed under the same conditions as the conditions under which the string 12 of interest is installed. The condition is that, for example, a light receiving surface that receives sunlight is directed in the same direction.

  For example, when the installation condition of the string 12 from which the actual integral value MI is derived is different from the installation condition of the string from which the reference value is derived, the first determination unit 40 may correct the actual integral value MI. Good. The corrected actual integration value MI is an integration value when it is assumed that the installation condition of the string 12 is the same as the installation condition of the string from which the reference value is derived. The correction value is determined by, for example, a difference value of various installation conditions such as a difference in solar radiation amount and a temperature difference in two strings. Further, the correction may be performed on the reference value.

  Next, the first determination unit 40 derives a decrease rate of the actually measured integral value MI with respect to the reference value (step S112).

  Next, the first determination unit 40 determines whether or not the decrease rate of the actually measured integral value MI and the power output of the string 12 satisfy a predetermined condition (step S114).

  The predetermined condition is, for example, a condition for determining whether or not the decrease rate of the actually measured integral value MI is included in a predetermined index range. The predetermined index range can be expressed by, for example, a reduction rate ± α (%) with respect to the integral value and a rate of output decrease ± β (%). Here, FIG. 5 is a diagram illustrating a relationship between the decrease rate of the actually measured integral value MI and the output decrease rate of the power of the string 12. In the figure, the vertical axis indicates the output decrease rate of the power of the string 12, and the horizontal axis indicates the decrease rate of the measured integral value MI.

  In FIG. 5, the 1-1 threshold value and the 1-2 threshold value indicate the range of the index with respect to the actually measured integrated value decrease rate (%), and the 2-1 threshold value and the 2-2 threshold value indicate the output decrease rate (%). ) Indicates the range of indicators. The predetermined condition in step S114 is that the decrease rate of the measured integral value MI is not less than the 1-1 threshold value, and the power output decrease rate of the string 12 is not less than the 2-1 threshold value. The first-first threshold is a value of about 1% to 9%, for example. More preferably, the first-first threshold is a value of about 3% to 4%. The 2-1 threshold value is smaller than the 1-1 threshold value. The 2-1 threshold value is a value of about 0.5% to 4%, for example. More preferably, the 2-1 threshold value is a value of about 1% to 2%. In the illustrated example, the reduction rate of the measured integral value MI is 3.77% (first threshold 1-1) or more, and the power output reduction rate of the string 12 is 1.48% or higher (second threshold 1). In this case, the first determination unit 40 determines that there is an abnormality in the string 12 of interest.

  Here, the first determination unit 40 may determine that “there is a high possibility that an abnormality exists” or “there is a suspicion that an abnormality exists” for the string 12 of interest. When the decrease rate of the measured integral value MI in the target string 12 is equal to or greater than the first-second threshold value and the power output decrease rate of the string 12 is equal to or greater than the second-second threshold value, the first determination unit 40 Is likely to exist ". For example, the first-second threshold is a value obtained by adding a value of about 3% to about 8% to the first-first threshold. In the illustrated example, the first-second threshold value is 8.77. For example, the 2-2th threshold is a value obtained by adding a value of about 1.5 to 2.5% to the 2-1th threshold. In the illustrated example, the 2-2 threshold value is 3.48%. For example, the difference between the 1-1 threshold value and the 1-2 threshold value is preferably about 5% (about ± 2.5% from the reference decrease rate). For example, the difference between the 2-1 threshold value and the 2-2 threshold value is preferably about 2% (± 1% from the standard output reduction rate).

  The first determination unit 40 may determine that “there is a suspicion that an abnormality exists” in the string 12 of interest when one or both of the following conditions (1) and (2) are satisfied. The condition (1) is that the power output decrease rate of the string 12 is not less than the 2-1 threshold value, and the decrease rate of the actually measured integral value MI is not less than the 1-1 threshold value and not more than the 1-2 threshold value. . The condition (2) is that the decrease rate of the measured integral value MI is not less than the 1-1 threshold value, the power output decrease rate of the string 12 is not less than the 2-1 threshold value, and not more than the 2-2 threshold value. .

  If the predetermined condition in step S114 is not satisfied, the first determination unit 40 determines that the string 12 of interest is normal (step S116), and ends the processing in this flowchart. This is because when the predetermined condition is not satisfied, the string 12 is operating normally. In this case, the first determination unit 40 may transmit the determination result to the management apparatus 100 using the communication unit 50.

  In addition, when the predetermined condition is satisfied, the second determination unit 42 derives the power output from the string 12 based on the current-voltage characteristic curve PL, first-order differentiates the derived power with the voltage value, and obtains the differential value. Derived (step S118). For example, the second determination unit 42 derives an output characteristic indicating the relationship between the power value output from the string 12 and the voltage value, and derives a differential value corresponding to the voltage value based on the derived output characteristic. Next, the second determination unit 42 determines whether or not the differential value matches the reference value a plurality of times (step S120). The reference value is, for example, 0 (zero). The reference value may be determined as a value having a predetermined range. When the differential value matches the reference value a plurality of times, the second determination unit 42 determines that there is an Isc mode abnormality (first abnormality) in the string 12 of interest (step S122). The Isc mode is an abnormality caused by a decrease in power output of the string 12 due to a decrease in current value.

  FIG. 6 is a diagram illustrating the relationship between the differential value and the voltage value in the power output by the string 12. In the figure, the vertical axis represents the differential value, and the horizontal axis represents the voltage value in the power output by the string 12. The voltage values in the figure are a certain range of voltage values between the voltage value Vpm and the open circuit voltage value Voc. In the illustrated example, the differential value is zero at three locations. Thus, when the differential value becomes zero a plurality of times, the abnormality of the string 12 of interest is classified into the Isc mode.

  When the differential value does not match the reference value a plurality of times (when the differential value matches the reference value only once), the type determination unit 44 plots the first differential value and the second differential value on the type determination map 48. Then, the presence / absence and type of the abnormality different from the first abnormality are determined based on the plotted result (step S124). The first differential value and the second differential value are differential values corresponding to two voltage values between the voltage value Vpm and the open circuit voltage value Voc. The first differential value is a differential value corresponding to a voltage value obtained by increasing the first voltage (for example, about 10 V) from the voltage value Vpm. The second differential value is a differential value corresponding to a voltage value obtained by increasing the second voltage (for example, about 20 V) from the voltage value Vpm.

  FIG. 7 is a diagram illustrating an example of the type determination map 48. In the figure, the horizontal axis indicates the first differential value. In the figure, the vertical axis represents the second differential value. The type determination map 48 is information in which an abnormality type is associated with each relationship between the first differential value and the second differential value, for example. The relationship between the first differential value and the second differential value is classified from the first region A1 to the fourth region A4. The first area A1 is an area belonging to the case where both the first differential value and the second differential value are the lowest. The second area A2 is an area belonging to a case where both the first differential value and the second differential value are lower than the first area A1. Next, the third region is a region belonging to the case where both the first differential value and the second differential value are lower next to the second region A2. Next, the fourth region is a region belonging to the case where both the first differential value and the second differential value are next to the third region A3. The boundary line of the area is not limited to the example shown in the figure. For example, an arbitrary boundary line may be set by an administrator or the like, and may be set according to the performance, scale, and the like of the string 12. The boundary line is not limited to a straight line, and may be a curved line or a stepped line.

  In addition to the above-mentioned Isc mode, the type of abnormality further includes a Voc mode, an Rs mode, or an Rsh mode. The Voc mode is an abnormality caused by a voltage drop of the string 12. The Rs mode is abnormal due to an increase in the series resistance of the string 12. The series resistance is, for example, the resistance of a semiconductor included in the power generation device 14 or the contact resistance between the semiconductor and the electrode. As the series resistance increases, the power generation efficiency decreases. The Rsh mode is an abnormality caused by a decrease in the parallel resistance of the string 12. The parallel resistance is a resistance component due to a leakage current of the power generation device 14. For example, if the insulation between the positive electrode and the negative electrode of the power generation device 14 is poor, the parallel resistance decreases and the power generation efficiency decreases.

  The first area A1 is an area in which the decrease rate of the actually measured integral value MI and the power output of the string 12 satisfy the predetermined condition, but are determined to be normal. The Voc mode is associated with the second area A2. The Rs mode is associated with the third region A3. The Rsh mode is associated with the fourth area A4.

  The type determination unit 44 plots the first differential value and the second differential value on the type determination map 48, and acquires a region associated with the plotted value. The type determination unit 44 determines the presence / absence and type of abnormality based on the acquired area.

  Next, the type determination unit 44 transmits the determined presence / absence of abnormality and the type to the management apparatus 100 (step S126). Thereby, the process of this flowchart is complete | finished.

  If the differential value does not coincide with the reference value even once, the second determination unit 42 may determine that the string 12 is normal. In addition, after determining the presence / absence and type of abnormality, the type determination unit 44 may correct the reference value in step S110 based on the type of abnormality. In the storage unit 46, for example, correction values associated with each abnormality type are stored. The first determination unit 40 compares the corrected reference value with the actually measured integral value MI derived in step S108, and based on the comparison result, whether or not the string 12 is abnormal or normal. It may be determined whether or not there is.

  In the above-described example, the example in which the presence / absence of abnormality and the abnormality type are determined based on the amount of change in power with respect to the voltage value has been described. Since the change in power depends on the change in voltage value or current value, the presence or absence of abnormality and the type of abnormality are determined based on the amount of change in current value with respect to voltage value or the amount of change in current value with respect to power. Good.

  For example, the type determination map 48 according to the embodiment includes the amount of change in the current value in a predetermined voltage range based on the first voltage value and the amount of change in the current value in the predetermined voltage range based on the second voltage value. Alternatively, it may be a type determination map associated with an abnormal type. In this case, the type determination unit 44 sets a predetermined voltage range centered on the first voltage, derives the first change amount of the current value in the set predetermined voltage range, and determines the predetermined voltage centered on the second voltage. A voltage range is set, and a second change amount of the current value in the set predetermined voltage range is derived. Then, the type determination unit 44 plots the derived first change amount and second change amount on the type determination map 48, acquires a region associated with the plotted value, and based on the acquired region, The presence / absence and type of abnormality may be determined.

  In the flowcharts described above, some processes may be executed. For example, in the flowchart described above, the power conversion device 30 may omit the process of determining the Isc mode and execute the process of determining the presence / absence and type of abnormality. For example, in this case, the power conversion apparatus 30 performs processing for deriving the actual integrated value MI, processing for determining whether or not the reduction rate and the power output satisfy predetermined conditions (for example, from step S104 to step S104 described above). S120) may be omitted. Furthermore, in this case, the power conversion device 30 derives the first differential value and the second differential value, and based on the result of plotting the derived first differential value and the second differential value on the type determination map 48, The presence / absence and type of an abnormality different from one abnormality is determined.

  Further, the power conversion device 30 may execute the process of determining the Isc mode, and omit the process of determining the presence and type of another abnormality (Voc mode, Rs mode, or Rsh mode). Further, the power conversion device 30 may execute the process of determining the Isc mode after the process of determining the presence and type of another abnormality (Voc mode, Rs mode, or Rsh mode).

  The management device 100 acquires the presence / absence and type of the determined abnormality from the power conversion device 30. The management apparatus 100 causes the display unit 112 to display the acquired presence / absence and type of abnormality. FIG. 8 is a diagram illustrating an example of the interface image IM displayed on the display unit 112 of the management apparatus 100. The interface image IM in FIG. 8 shows a display example when it is determined that the string 12 is abnormal. In the example of FIG. 8, “power generation unit ID”, “string ID”, “abnormality type”, “installation location”, “manager information”, and the like are shown as items to be displayed. Items and screen layouts are not limited to this. “Power generation unit ID” indicates identification information of the power generation unit 10 including the abnormal string 12. “String ID” indicates information indicating that an abnormal string 12 exists. The “abnormality type” indicates information indicating the type of abnormality, and the “installation location” indicates the installation location of the power generation unit 10. The “manager information” indicates the address or contact information of the manager of the power generation module. The interface image IM may be displayed on a display unit included in the HEMS 50.

  Further, the display unit 112 may display information indicating the relationship between the decrease rate of the actually measured integral value MI illustrated in FIG. 5 and the output decrease rate of the power of the string 12. Further, the display unit 112 may display information indicating the relationship between the differential value of the current-voltage characteristic curve PL illustrated in FIG. 6 and the voltage value output by the string 12. Further, the display unit 112 may display the result of plotting the first differential value and the second differential value shown in FIG.

  The presence / absence and type of abnormality are displayed on the display unit 112 of the management apparatus 100, for example. In this case, a maintenance person who maintains the power generation unit 10 can specify the presence / absence and type of the string 12 based on the information displayed on the display unit 112. Then, the maintenance staff can recognize the degree of abnormality of the string 12, the urgency of repairing the string 12, and the like. Therefore, according to the first embodiment, the person in charge of maintenance estimates whether the abnormality is such that it can be left as it is or whether it is an abnormality that must be checked immediately. Therefore, the maintenance work efficiency for the power generation unit 10 can be improved.

  In the solar cell monitoring system 1 of the first embodiment described above, the integrated value obtained by integrating the current value in the current-voltage characteristic curve from the voltage value set with the operating point as a reference to the upper limit value is the reference value. If it is determined that the value has decreased by a predetermined value or more, information indicating that the string 12 is abnormal is output. As a result, it is possible to relax the limitation on the operation of the solar cell and determine the abnormality of the solar cell.

  Moreover, the solar cell monitoring system 1 of 1st Embodiment is the 1st voltage value and 2nd voltage value which are contained between the voltage value set on the basis of the operating point in a current-voltage characteristic curve to an open circuit voltage value. The presence / absence and type of the string 12 is determined based on the change in the current value with respect to. As a result, it is possible to determine not only the presence / absence of an abnormality of the solar cell but also the type of abnormality.

(Second Embodiment)
Hereinafter, the second embodiment will be described. Here, the description will focus on differences from the first embodiment, and descriptions of functions and the like common to the first embodiment will be omitted. In the second embodiment, the management apparatus 100 performs processing related to determination of abnormality of the string 12.

  FIG. 9 is a diagram illustrating a functional configuration of the solar cell monitoring system 1A according to the second embodiment. The solar cell monitoring system 1A includes a power conversion device 30A and a management device 100A. The power conversion device 30 </ b> A includes a power conversion unit 32, a current / voltage acquisition unit 34, a conversion control unit 36, and a communication unit 50. The power conversion unit 32, the current / voltage acquisition unit 34, the conversion control unit 36, and the communication unit 50 have the same functional configuration as the functional units to which the same reference numerals are assigned in the first embodiment, and thus description thereof is omitted. .

  The management device 100A includes a communication unit 110, a display unit 112, a characteristic derivation unit 120, a first determination unit 122, a second determination unit 124, a type determination unit 126, and a storage unit 130. The communication unit 110, the display unit 112, the characteristic derivation unit 120, the first determination unit 122, the second determination unit 124, the type determination unit 126, and the storage unit 130 are respectively the communication unit 50 and the display unit 112 of the first embodiment. Since the functional configuration is the same as that of the characteristic deriving unit 38, the first determination unit 40, the second determination unit 42, the type determination unit 44, and the storage unit 46, description thereof will be omitted. The storage unit 130 includes reference data 132 and a type determination map 134. Since the reference data 132 and the type determination map 134 are the same as the reference data 47 and the type determination map 48, respectively, description thereof will be omitted.

  The power conversion device 30A acquires the current value and the voltage value detected by the detection unit 22, and transmits the acquired current value and voltage value to the management device 100A. The management device 100 acquires the current value and the voltage value transmitted by the power conversion device 30A. Characteristic deriving unit 120 transmits an instruction signal for searching for an operating point to power conversion device 30A based on the acquired current value and voltage value. Characteristic deriving unit 120 obtains voltage value Vpm and current value Ipm at the operating point. Further, the characteristic deriving unit 120 controls the power conversion device 30A to change the voltage value Vpm to obtain the open circuit voltage value Voc. The characteristic deriving unit 120 acquires a current-voltage characteristic curve PL in the range between the voltage value Vpm and the open circuit voltage value Voc.

  And the 1st determination part 122 determines the abnormality of the string 12 to which its attention is paid based on the decreasing rate of the measured integral value MI. The second determination unit 124 derives the power output from the string 12 based on the current-voltage characteristic curve PL, and determines the abnormality of the string 12 of interest based on the differential value obtained by first-ordering the derived power with the voltage value. To do. The type determination unit 126 plots the first differential value and the second differential value on the type determination map 48, and determines the presence and type of an abnormality different from the first abnormality based on the plotted result.

  According to the second embodiment described above, since the management device 100A determines the presence / absence and type of the string 12, the processing load on the power conversion device 30A can be reduced.

  The functions of the characteristic deriving unit 38 (120), the first determination unit (40) 122, the second determination unit 42 (124), the type determination unit (44) 126, and the storage unit (46) 130 in the above-described embodiment. The unit may be provided in one device or may be distributed and provided in a plurality of devices. When a functional unit is provided in a plurality of devices, each functional unit provided in the plurality of devices cooperates to execute processing.

  As mentioned above, although the form for implementing this invention was demonstrated using embodiment or experiment result, this invention is not limited to such embodiment or experiment result, and in the range which does not deviate from the summary of this invention. Various modifications and substitutions can be made in.

DESCRIPTION OF SYMBOLS 1,1A ... Solar cell monitoring system, 10 ... Power generation unit, 30, 30A ... Power converter, 32 ... Power converter, 34 ... Current voltage acquisition part, 36 ... Conversion control part, 38, 120 ... Characteristic derivation part, 40 122, first determination unit, 42, 124 ... second determination unit, 44, 126 ... type determination unit, 46, 130 ... storage unit, 47, 132 ... reference data, 48, 134 ... type determination map,
50, 110 ... communication unit, 100, 100A ... management device, 112 ... display unit

Claims (15)

An acquisition unit for acquiring a current value and a voltage value in the power output from the solar cell;
Among the current value and voltage value acquired by the acquisition unit, from the voltage value set on the basis of the operating point that is the current value and voltage value when the output value of the power is good, the open voltage value direction A deriving unit for deriving a current-voltage characteristic curve;
The integrated value obtained by integrating the current value in the current-voltage characteristic curve derived by the deriving unit between the voltage value set with the operating point as a reference and the upper limit value is decreased by a predetermined value or more compared to the reference value. A first determination unit for determining whether or not
An output unit that outputs information indicating that the solar cell is abnormal when it is determined by the first determination unit that the value has decreased by a predetermined value or more;
A solar cell monitoring system comprising: The upper limit value is the open circuit voltage value.
The solar cell monitoring system according to claim 1. When it is determined by the first determination unit that the integral value has decreased by a predetermined value or more,
A second determination unit that determines abnormality of the solar cell based on a change in current value in the current-voltage characteristic curve derived by the deriving unit;
The solar cell monitoring system according to claim 2. The second determination unit derives a differential value obtained by differentiating power derived based on the current-voltage characteristic curve with a voltage value, and determines a type of abnormality of the solar cell based on the derived differential value.
The solar cell monitoring system according to claim 3. The second determination unit determines that the abnormality of the solar cell is a first abnormality caused by a decrease in a current value in the power when the derived differential value becomes zero a plurality of times.
The solar cell monitoring system according to claim 4. When the derived differential value is zero once, the solar cell abnormality is a type of abnormality different from the first abnormality when the derived differential value is zero multiple times. Judge that there is
The solar cell monitoring system according to claim 4 or 5. An abnormality of a type different from the first abnormality is a second abnormality caused by a decrease in parallel resistance of the solar cell, a third abnormality caused by a decrease in a voltage value in the power, and / or a series of the solar cells. Including a fourth anomaly due to increased resistance,
The solar cell monitoring system according to claim 6. A differential value obtained by differentiating the power corresponding to the first voltage value included between the open-circuit voltage value from the voltage value set with reference to the operating point in the current-voltage characteristic curve derived by the deriving unit, And determining the type of abnormality based on a differential value obtained by differentiating the power corresponding to a second voltage value included between an open-circuit voltage value and a voltage value set with the operating point as a reference. An abnormality type determination unit is further provided.
The solar cell monitoring system according to any one of claims 4 to 7. The abnormality type determination unit refers to a type determination map in which an abnormality type is associated with the differential value obtained by differentiating the power corresponding to the first voltage value with a voltage value, and the second voltage value. Based on a differential value obtained by differentiating the corresponding power with a voltage value, the type of the abnormality is determined.
The solar cell monitoring system according to claim 8. The output unit outputs information for causing the display unit to display the type of abnormality determined by the abnormality type determination unit.
The solar cell monitoring system according to claim 8 or 9. An acquisition unit for acquiring a current value and a voltage value in the power output from the solar cell;
A derivation unit for deriving a current-voltage characteristic curve based on the current value and the voltage value acquired by the acquisition unit;
Based on the change in the current value with respect to the first voltage value and the second voltage value included between the voltage value set based on the operating point in the current-voltage characteristic curve derived by the deriving unit and the open-circuit voltage value. An abnormality type determination unit for determining the type of abnormality of the solar cell;
An output unit that outputs information indicating the type of abnormality of the solar cell determined by the abnormality type determination unit;
A solar cell monitoring system comprising: A first determination unit that determines whether or not an integral value related to the current-voltage characteristic curve derived by the deriving unit is decreased by a predetermined value or more compared to a reference value;
When it is determined by the first determination unit that the abnormality type determination unit has decreased by a predetermined value or more, the abnormality type determination unit is configured to change the current value of the solar cell based on a change in current value with respect to the first voltage value and the second voltage value. Determine the type of anomaly,
The solar cell monitoring system according to claim 11. The type of abnormality is a second abnormality caused by a decrease in the parallel resistance of the solar cell, a third abnormality caused by a decrease in the voltage value of the power, and / or a first abnormality caused by an increase in the series resistance of the solar cell. Including 4 abnormalities,
The solar cell monitoring system according to claim 11 or 12. On the computer,
Get the current value and voltage value in the power output from the solar cell,
Based on the acquired current value and voltage value, the current-voltage characteristic in the direction of the open-circuit voltage value from the voltage value set with reference to the operating point that is the current value and voltage value when the output value of the power is good Let the curve be derived,
Whether the integrated value obtained by integrating the current value in the derived current-voltage characteristic curve between the voltage value set with the operating point as a reference and the upper limit value is decreased by a predetermined value or more compared to the reference value Whether or not
When it is determined that the predetermined value or more has been decreased, information indicating that the solar cell is abnormal is output.
Solar cell monitoring program. On the computer,
Get the current value and voltage value in the power output from the solar cell,
Based on the obtained current value and voltage value, a current-voltage characteristic curve is derived,
Based on a change in current value with respect to a first voltage value and a second voltage value included between a voltage value set with reference to an operating point in the derived current-voltage characteristic curve and an open-circuit voltage value, the sun Let us determine the type of battery abnormality,
Outputting information indicating the determined type of abnormality of the solar cell,
Solar cell monitoring program.

Images