Output control device

Abstract

To provide an output control device which can continue operations of a plurality of power conversion devices even when it becomes impossible to acquire information about measurement values.SOLUTION: There is provided an output control device comprising a control unit which calculates a plurality of individual output control values representing the magnitude of power for restricting output for each of a plurality of power conversion devices on the basis of information on output control values, information on measurement values, and information on a plurality of pieces of individual output power and performs output control of the plurality of power conversion devices on the basis of the plurality of individual output control values. The control unit allows output control of the plurality of power conversion devices to be continued by calculating the total value of the magnitude of power to be output from each of the plurality of power conversion devices on the basis of information on the plurality of pieces of individual output power and calculating the plurality of individual output control values on the basis of the information on the output control values, the information on the plurality of pieces of individual output power, and the total value when information on the measurement values cannot be acquired.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD An embodiment of the present invention relates to an output control device. [Background technology]

[0002] There is an output control device that controls the output of multiple power conversion devices that output power supplied from multiple distributed power sources to a power grid. Distributed power sources are generators that use renewable energy, such as solar power generators, wind power generators, and geothermal power generators. The output control device is used, for example, in a power generation facility that includes multiple distributed power sources and multiple power conversion devices.

[0003] The output control device acquires information on output control values and information on time periods for output control (schedule information) from a power server or the like, and also acquires information on measurement values measuring the amount of power output from each power conversion device to the power grid at an interconnection point between multiple power conversion devices and the power grid from a power meter, monitoring device, etc. Based on the acquired information, the output control device controls the amount of power output from each power conversion device so that the amount of power output to the interconnection point corresponds to the output control value.

[0004] If the output control device is unable to obtain measurement value information due to a malfunction of the power meter or monitoring device, or a communication abnormality, it will stop operation of each power conversion device because it will become difficult to control the output of each power conversion device.

[0005] However, stopping the operation of each power conversion device means that the power of each distributed power source cannot be effectively utilized. For example, if each distributed power source is a generator that uses renewable energy, the power generated by each distributed power source will be wasted.

[0006] For this reason, it is desirable for the output control device to be able to continue operating the multiple power conversion devices even when it becomes impossible to acquire information on the measured values. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 7098867 Summary of the Invention [Problem to be solved by the invention]

[0008] An embodiment of the present invention provides an output control device that can continue to operate a plurality of power conversion devices even when it becomes impossible to acquire information on measured values. [Means for solving the problem]

[0009] According to an embodiment of the present invention, there is provided an output control device that controls the output of a plurality of power conversion devices that output power supplied from a plurality of distributed power sources to a power grid, the output control device including an information acquisition unit that acquires information on output control values that indicate the magnitude of power that is to be limited to output from the plurality of power conversion devices to the power grid, information on measurement values that measure the magnitude of power that is output from the plurality of power conversion devices to the power grid at interconnection points between the plurality of power conversion devices and the power grid, and information on a plurality of individual output powers that indicate the magnitude of power that is to be output from each of the plurality of power conversion devices, based on the information on the output control values, the information on the measurement values, and the information on the plurality of individual output powers. and a control unit that controls the outputs of the plurality of power conversion devices so that the magnitude of the power output from the plurality of power conversion devices to the power grid is a magnitude that corresponds to the output control values by calculating individual output control values of the plurality of individual output powers and causing each of the plurality of power conversion devices to output power of a magnitude that corresponds to the plurality of individual output control values, wherein when the control unit cannot obtain information on the measurement values, the control unit calculates a total value of the magnitude of the power output from each of the plurality of power conversion devices based on information on the plurality of individual output powers, and calculates the plurality of individual output control values based on information on the output control values, information on the plurality of individual output powers, and the total value, thereby enabling continuous output control of the plurality of power conversion devices. [Effects of the Invention]

[0010] An output control device is provided that can continue to operate a plurality of power conversion devices even when it becomes impossible to acquire information on measured values. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a block diagram schematically illustrating a solar power generation system according to an embodiment. [Figure 2] 4 is a flowchart schematically illustrating an example of an operation of the output control device according to the embodiment.

[0012] Each embodiment will be described below with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as those in reality. Furthermore, even when the same part is shown, the dimensions and ratios may be different depending on the drawing. In the present specification and the drawings, elements similar to those described above with reference to the previous drawings are designated by the same reference numerals, and detailed descriptions thereof will be omitted as appropriate.

[0013] FIG. 1 is a block diagram schematically illustrating a solar power generation system according to an embodiment. 1, a solar power generation system 10 (distributed power system) includes an output control device 12 and a plurality of power conversion devices 14. The plurality of power conversion devices 14 are connected to a plurality of solar panels 2 (distributed power sources) and also to a power grid 4. The power of the power grid 4 is AC power. In other words, the power grid 4 is an AC power grid.

[0014] The solar power generation system 10 further includes, for example, a plurality of transformers 16, 18 and a power receiving and transforming facility 20. The plurality of power conversion devices 14 are connected to the power grid 4 via the transformers 16, 18, the power receiving and transforming facility 20, and the like. The power receiving and transforming facility 20 includes, for example, a transformer and a circuit breaker. However, the transformers 16, 18 and the power receiving and transforming facility 20 are provided as needed and can be omitted. The connection configuration between the plurality of power conversion devices 14 and the power grid 4 may be any configuration that allows the plurality of power conversion devices 14 to be appropriately connected to the power grid 4.

[0015] The multiple power conversion devices 14 convert the power supplied from the multiple solar panels 2 into power compatible with the power grid 4, and output the converted power to the power grid 4. The power supplied from the multiple solar panels 2 is DC power. In other words, the multiple power conversion devices 14 convert the DC power supplied from the multiple solar panels 2 into AC power compatible with the power grid 4, and output the converted AC power to the power grid 4.

[0016] The solar power generation system 10 is used, for example, in a power generation facility equipped with a plurality of solar panels 2. The plurality of power conversion devices 14, for example, sell the electric power generated by each solar panel 2 to a power grid 4.

[0017] The number of the multiple power conversion devices 14 is, for example, the same as the number of the multiple solar panels 2. The multiple power conversion devices 14 are, for example, connected to each of the multiple solar panels 2. However, the number of the multiple power conversion devices 14 does not necessarily have to be the same as the number of the multiple solar panels 2. For example, multiple solar panels 2 may be connected to one power conversion device 14. Conversely, multiple power conversion devices 14 may be connected to one solar panel 2. The multiple power conversion devices 14 may have any configuration that allows them to appropriately output power supplied from the multiple solar panels 2 to the power grid 4.

[0018] The multiple power conversion devices 14 each include, for example, a converter 30 and a communication device 32. The converter 30 is connected to the solar panels 2 and the power grid 4. The converter 30 converts power supplied from the connected solar panels 2 into power compatible with the power grid 4, and outputs the converted power to the power grid 4.

[0019] The communicator 32 communicates with the output control device 12. The converter 30 converts the power supplied from the solar panel 2 based on a signal input from the output control device 12 via the communicator 32, for example.

[0020] The photovoltaic power generation system 10 further includes, for example, a power meter 22 and a monitoring device 24. The power meter 22 measures the magnitude of power output from the multiple power conversion devices 14 to the power system 4 at a point of interconnection CP between the multiple power conversion devices 14 and the power system 4. For example, when each power conversion device 14 is connected to the power system 4 via each transformer 16, 18, a substation 20, etc., the power meter 22 is provided at a position closer to the point of interconnection CP than the transformers 16, 18 and the substation 20. The power meter 22 is provided, for example, near the point of interconnection CP. In this way, the power meter 22 measures the magnitude of power output from each power conversion device 14 to the point of interconnection CP (power system 4).

[0021] The monitoring device 24 is connected to the power meter 22 and acquires measurement values of the magnitude of the power output from the multiple power conversion devices 14 to the power grid 4, measured by the power meter 22. The monitoring device 24 acquires digital measurement values, for example, by performing AD conversion on the analog measurement values output from the power meter 22. The monitoring device 24 acquires digital measurement values that represent the magnitude of the power output to the power grid 4, for example, by converting the analog measurement values output from the power meter 22 in the range of 4 mA to 20 mA during AD conversion.

[0022] The output control device 12 controls the output of the multiple power conversion devices 14. The output control device 12 includes an information acquisition unit 40 and a control unit 42. The information acquisition unit 40 acquires information on output control values that indicate the magnitude of power that limits the output from the multiple power conversion devices 14 to the power grid 4, information on measurement values that measure the magnitude of power output from the multiple power conversion devices 14 to the power grid 4 at an interconnection point CP between the multiple power conversion devices 14 and the power grid 4, and information on multiple individual output powers that indicate the magnitude of power output from each of the multiple power conversion devices 14.

[0023] In other words, the information on the output control value is information that indicates the upper limit of the amount of power that is permitted to be output from the multiple power conversion devices 14 to the power grid 4. The output control value is set, for example, by a power company or the like that manages the power grid 4 in order to adjust the supply and demand balance of the power grid 4.

[0024] The information acquiring unit 40 acquires information about the output control value from the power server 6 managed by the power company, for example, by communicating with the power server 6. However, the method for acquiring the information about the output control value is not limited to the above, and any method that can appropriately acquire the information about the output control value may be used. The information about the output control value may be acquired, for example, from another control device that controls the operation of multiple power conversion devices 14. The information about the output control value may be acquired, for example, from an operation unit such as a keyboard or mouse provided in the output control device 12. In other words, the information about the output control value may be manually input to the information acquiring unit 40 via the operation unit.

[0025] The information acquiring unit 40 acquires information on the measurement values from the monitoring device 24, for example, by communicating with the monitoring device 24. The information acquiring unit 40 may acquire information on the measurement values from the power meter 22, for example, by receiving an analog output from the power meter 22 and performing AD conversion in the information acquiring unit 40. In this case, the monitoring device 24 can be omitted. However, the method for acquiring information on the measurement values is not limited to the above, and any method that can appropriately acquire information on the measurement values may be used.

[0026] The information acquiring unit 40 acquires information on the individual output power from each of the plurality of power electronics devices 14, for example, by communicating with the respective communicators 32 of the plurality of power electronics devices 14. However, the method for acquiring the information on the plurality of individual output powers is not limited to the above, and any method that can appropriately acquire information on the plurality of individual output powers may be used. The information on the plurality of individual output powers may also be acquired, for example, from another control device that controls the operation of the plurality of power electronics devices 14.

[0027] The information acquiring unit 40 is, for example, a communicator for communicating with the power server 6, the monitoring device 24, the communicator 32, etc. The information acquiring unit 40 may have, for example, a function for receiving an analog output from the power meter 22 or a function for receiving an operation signal from an operation unit. The information acquiring unit 40 may have any configuration that can appropriately acquire information on output control values, information on measurement values, and information on a plurality of individual output powers.

[0028] Based on the information on the output control values, the information on the measurement values, and the information on the plurality of individual output powers, the control unit 42 calculates a plurality of individual output control values that indicate the magnitude of power that limits the output of each of the plurality of power electronics devices 14. In other words, the plurality of individual output control values are information that indicates the upper limit of the magnitude of power that is permitted to be output from each of the plurality of power electronics devices 14.

[0029] For example, if the rated outputs of multiple power conversion devices 14 are the same, the control unit 42 calculates multiple individual output control values by dividing the magnitude of the power represented by the output control value information by the number of multiple power conversion devices 14.

[0030] When the rated outputs of the multiple power electronics devices 14 are different, the control unit 42 calculates multiple individual output control values by dividing the magnitude of the power represented by the information on the output control value by the number of the multiple power electronics devices 14, and then multiplying the result by a coefficient according to the rated output of each power electronics device 14. In this way, the multiple individual output control values may be control values of different magnitudes set corresponding to each of the multiple power electronics devices 14.

[0031] Furthermore, when the distributed power sources are solar panels 2, the amount of power supplied from each solar panel 2 may differ due to the influence of clouds or the like. For this reason, the control unit 42 may adjust the amount of power to limit the output of each power conversion device 14, for example, according to the amount of power supplied from each solar panel 2 (the power generated by each solar panel 2). For example, the control unit 42 may multiply the current output power represented by the information on the multiple individual output powers by a coefficient corresponding to the output control value. This makes it possible to adjust the amount of power to limit the output of each power conversion device 14, according to the current output power of each power conversion device 14 (the power generated by each solar panel 2). For example, the multiple individual output control values may be adjusted so that the individual output control value of a power conversion device 14 with a small amount of spare power generated by the solar panel 2 is reduced, and the individual output control value of a power conversion device 14 with a large amount of spare power generated by the solar panel 2 is increased.

[0032] However, the method of calculating the multiple individual output control values by the control unit 42 is not limited to the above, and any calculation method that can appropriately calculate the multiple individual output control values based on information on the output control values, information on the measurement values, and information on the multiple individual output powers may be used.

[0033] The control unit 42 causes each of the multiple power electronics devices 14 to output power of a magnitude corresponding to the multiple individual output control values. The control unit 42, for example, communicates with the multiple power electronics devices 14 (communicators 32) and transmits each of the multiple calculated individual output control values to each of the multiple corresponding power electronics devices 14, thereby causing each of the multiple power electronics devices 14 to output power of a magnitude corresponding to the multiple individual output control values. In this way, the control unit 42 controls the output of the multiple power electronics devices 14 so that the magnitude of power output from the multiple power electronics devices 14 to the power grid 4 corresponds to the output control values.

[0034] Furthermore, the control unit 42 acquires information on the output control value from the power server 6 via the information acquisition unit 40, for example, and also acquires information on the time period of output control from the power server 6. The information on the time period of output control is information that indicates the time period during which output control is performed according to the output control value. In other words, the information on the time period of output control is schedule information. Note that the method of acquiring the information on the time period of output control is not limited to from the power server 6, and any method may be used.

[0035] When the control unit 42 has previously acquired information on the time period for output control from the power server 6 or the like, the control unit 42 controls the outputs of the multiple power electronics devices 14 in the time period indicated by the time period information, as described above.

[0036] The information acquiring unit 40 acquires information on the output control values for one day and information on the time period for output control by communicating with the power server 6, for example, at the beginning of each day. Meanwhile, the information acquiring unit 40 periodically acquires information on the measurement values and information on the multiple individual output powers, for example, by periodically communicating. This allows output control to be performed based on the current measurement values and the output power of each power electronics device 14.

[0037] The information acquisition unit 40, for example, periodically communicates with each power electronics device 14 and periodically acquires status monitoring information including information on individual output power from each power electronics device 14. The status monitoring information may further include, for example, information indicating the presence or absence of an abnormality in the converter 30 in addition to information on individual output power. The status monitoring information may include at least information on individual output power. The information included in the status monitoring information may be any information necessary for monitoring the status of the power electronics device 14.

[0038] The information on the output control values may be input to the output control device 12 from the power server 6 or the like at any timing required to adjust the supply and demand balance of the power grid 4. The control unit 42 may, for example, periodically acquire information on the measurement values and information on the plurality of individual output powers, and perform output control of the plurality of power conversion devices 14 as described above at the timing when the information on the output control values is received. The information on the output control values may also be acquired periodically, similar to the information on the measurement values and information on the plurality of individual output powers.

[0039] For example, the information acquiring unit 40 may be unable to acquire information on the measurement values due to a malfunction of the power meter 22, the monitoring device 24, or the like, or a communication error. For example, when the control unit 42 is unable to communicate with the power meter 22, the monitoring device 24, or the like, or when the measurement values acquired from the power meter 22, the monitoring device 24, or the like indicate abnormal values, the control unit 42 determines that it is unable to acquire information on the measurement values.

[0040] As described above, when the control unit 42 is unable to acquire information on measurement values due to equipment failure, communication abnormality, or the like, it calculates a total value of the magnitude of power output from each of the multiple power electronics devices 14 based on information on the multiple individual output powers, and calculates multiple individual output control values based on information on the output control value, information on the multiple individual output powers, and the total value, thereby enabling continuous output control of the multiple power electronics devices 14. In other words, when the control unit 42 is unable to acquire information on measurement values, it replaces the output power of each power electronics device 14 measured at the interconnection point CP with the total value of the individual output powers of each power electronics device 14, and calculates multiple individual output control values.

[0041] For example, in calculating the total value, the control unit 42 adds a fixed value to the sum of the magnitudes of the power output from each of the multiple power electronics devices 14. The magnitude of the power output from the multiple power electronics devices 14 to the power system 4 at the interconnection point CP may be smaller than the sum of the magnitudes of the power output from each of the multiple power electronics devices 14 due to losses on the paths between the interconnection point CP and each power electronics device 14, such as the transformers 16, 18 and the substation equipment 20. For this reason, when output control of each power electronics device 14 is performed based on the sum of the magnitudes of the power output from each of the multiple power electronics devices 14, there is a concern that the magnitude of the power output to the interconnection point CP will be smaller by the amount of losses on the paths compared to when output control is performed based on the measurement value at the interconnection point CP.

[0042] Therefore, the control unit 42 calculates a total value by adding a fixed value to the sum of the magnitudes of the power output from each of the multiple power electronics devices 14. The fixed value is set according to the loss on the path. This makes it possible to suppress the influence of the loss on the path even when output control is performed based on the total value.

[0043] The control unit 42 receives fixed value information indicating the magnitude of the fixed value and can change the magnitude of the fixed value based on the fixed value information. Losses on the path vary depending on the influence of the transformers 16, 18, the substation equipment 20, etc., and are difficult to predict in advance. For this reason, the magnitude of the fixed value can be changed based on the results of measuring losses when the solar power generation system 10 is actually operated. This allows the magnitude of the fixed value to be set more appropriately. For example, the influence of losses on the path can be further suppressed, and even when a fixed value is added, the magnitude of the power output to the interconnection point CP can be prevented from exceeding the output control value.

[0044] The fixed value information may be input, for example, based on the operation of an operation unit connected to the control unit 42, or may be input from an external device that communicates with the control unit 42. The external device may be, for example, the power server 6. The external device may also be, for example, a terminal of an administrator who manages the solar power generation system 10. The external device may be any device that can appropriately input the fixed value information to the control unit 42. However, the method of inputting the fixed value information is not limited to the above and may be any method.

[0045] The control unit 42 does not necessarily have to be able to change the magnitude of the fixed value. The fixed value may be a predetermined value that is set in advance. Furthermore, the control unit 42 does not have to add the fixed value to the calculation of the total value. The control unit 42 may calculate the sum of the magnitudes of the power output from each of the multiple power electronics devices 14 as the total value.

[0046] When the control unit 42 is unable to acquire information on the measurement values, it is possible to switch between control for continuing the output control of the multiple power conversion devices 14 by calculating the total value and control for stopping the operation of the multiple power conversion devices 14. In other words, the control unit 42 allows the user to set in advance whether to continue the output control or stop the operation when the control unit 42 is unable to acquire information on the measurement values.

[0047] The control unit 42 switches between control for continuing output control and control for stopping operation, for example, in response to an external switching signal input. The switching signal may be input based on the operation of an operation unit connected to the control unit 42, as with the fixed value information, or may be input from an external device that communicates with the control unit 42. The method for inputting the switching signal is not limited to the above and may be any method.

[0048] For example, depending on the electric power company that manages the electric power grid 4, output control based on the total value may not be permitted. Therefore, in this case, the control is switched to control to stop operation. This allows the output control device 12 to handle both cases where output control based on the total value is permitted and where output control based on the total value is not permitted. For example, the versatility of the output control device 12 can be improved. For example, even if the cases where output control based on the total value is permitted and where output control based on the total value is not permitted change during operation of the photovoltaic power generation system 10, the control device 42 can appropriately respond. However, the control unit 42 does not necessarily have to be able to switch between control to continue output control and control to stop operation. It is sufficient for the control unit 42 to at least execute control to continue output control.

[0049] The control unit 42 is connected to the communicator 32 of each power electronics device 14 via a communication line, for example, and communicates with the communicator 32 to transmit each of the calculated individual output control values to the corresponding power electronics devices 14. The converter 30 of each power electronics device 14 converts power so as to output power of a magnitude corresponding to the individual output control value input via the communicator 32.

[0050] Furthermore, the control unit 42 is connected to the converters 30 of each power conversion device 14 via, for example, a hardwire, and when performing control to stop operation, inputs an operation stop signal to the converters 30 of each power conversion device 14 via a contact input via the hardwire. In response to the input of the operation stop signal from the control unit 42, the converters 30 of each power conversion device 14 stop their power conversion operation and stop outputting power to the power grid 4. In this way, the operation stop signal is input via a contact input via the hardwire. This reduces communication delays and allows the operation of the converters 30 to be stopped more quickly than when communication is performed via the communicator 32. However, the method of inputting the multiple individual output control values and the operation stop signal to each power conversion device 14 is not limited to the above and may be any method.

[0051] Furthermore, when the control unit 42 is unable to acquire the information on the measurement values, it issues a notification indicating that the information on the measurement values cannot be acquired. For example, the control unit 42 notifies the external device that the information on the measurement values cannot be acquired by transmitting information indicating that the information on the measurement values cannot be acquired to the external device. As described above, the external device is the power server 6, the manager's terminal, or the like. For example, the control unit 42 notifies the power company, the manager of the solar power generation system 10, or the like by transmitting information.

[0052] The mode of notification indicating that measurement value information cannot be acquired is not limited to transmitting information to an external device, but may be, for example, displaying information on a display device connected to the control unit 42, turning on a warning light connected to the control unit 42, or outputting audio from a speaker connected to the control unit 42. The mode of notification indicating that measurement value information cannot be acquired may be any mode that can appropriately notify the electric power company, a manager, or the like that measurement value information cannot be acquired.

[0053] By issuing a notification in this way, it is possible to notify the power company, administrator, etc. of the occurrence of an abnormality that makes it impossible to acquire measurement value information. For example, it is possible to prompt the execution of maintenance, etc., and to more quickly recover from a malfunction or communication abnormality in the power meter 22 or the monitoring device 24. However, the control unit 42 does not necessarily have to issue a notification that measurement value information cannot be acquired.

[0054] FIG. 2 is a flowchart schematically illustrating an example of the operation of the output control device according to the embodiment. 2, the information acquisition unit 40 of the output control device 12 acquires information on output control values, information on measurement values, and information on a plurality of individual output powers. The information acquisition unit 40 acquires information on output control values from the power server 6, for example, by communicating with the power server 6. At this time, the information acquisition unit 40 also acquires information on the time period for output control from the power server 6 as necessary.

[0055] The information acquiring unit 40 acquires information on measurement values, for example, by communicating with the monitoring device 24 or by receiving input of an analog output from the power meter 22. The information acquiring unit 40 then acquires information on a plurality of individual output powers, for example, by periodically communicating with each power electronics device 14 and acquiring status monitoring information including information on individual output powers from each power electronics device 14. Note that in FIG. 2, each power electronics device 14 is denoted as "PCS" for convenience.

[0056] The control unit 42 determines whether or not the information on the measurement values can be acquired based on the result of acquisition of the information on the measurement values by the information acquisition unit 40 (step S101 in FIG. 2). If the control unit 42 determines that the information on the measurement values can be acquired, it calculates a plurality of individual output control values based on the information on the output control values, the information on the measurement values, and the information on the plurality of individual output powers (step S102 in FIG. 2).

[0057] After calculating a plurality of individual output control values, the control unit 42 transmits each of the calculated individual output control values to each of the corresponding plurality of power conversion devices 14, and causes each of the plurality of power conversion devices 14 to output power of a magnitude corresponding to the plurality of individual output control values, thereby controlling the output of the plurality of power conversion devices 14 so that the magnitude of power output from the plurality of power conversion devices 14 to the power grid 4 corresponds to the output control values.

[0058] On the other hand, if the control unit 42 determines that the information cannot be acquired, it issues a notification indicating that the information on the measurement value cannot be acquired (step S103 in FIG. 2). In other words, when the control unit 42 is unable to acquire the information on the measurement value, it issues a notification indicating that the information on the measurement value cannot be acquired. This allows for quicker recovery from device failures, communication abnormalities, and the like, as described above.

[0059] Furthermore, when the control unit 42 determines that the information cannot be acquired, it issues a notification and checks whether the control is set to continue the output control or to stop the operation (step S104 in FIG. 2). In this way, by being able to switch between the control to continue the output control and the control to stop the operation when the information on the measurement value cannot be acquired, the versatility of the output control device 12 can be improved as described above.

[0060] When control to stop operation is set, the control unit 42 inputs a signal to stop operation to the converter 30 of each power conversion device 14, thereby causing the converter 30 of each power conversion device 14 to stop converting power.

[0061] When control to continue the output control is set, the control unit 42 calculates the total value of the magnitude of the power output from each of the multiple power conversion devices 14 based on information on the multiple individual output powers (step S105 in Figure 2).

[0062] For example, when the number of multiple power electronics devices 14 is N and the individual output powers of the power electronics devices 14 are P_A, P_B···P_N, the control unit 42 calculates the total value as P_A+P_B+···+P_N.

[0063] Furthermore, at this time, the control unit 42 calculates a total value by adding a fixed value to the sum of the magnitudes of the power output from each of the multiple power electronics devices 14, as necessary. For example, when the fixed value is P_X, the control unit 42 calculates the total value using P_A+P_B+···+P_N+P_X. This makes it possible to suppress the impact of losses on the path even when output control is performed based on the total value, as described above. For example, even when selling power based on the power generated by the solar panel 2 (distributed power source), it is possible to suppress a decrease in power selling revenue.

[0064] After calculating the total value, the control unit 42 continues to control the outputs of the multiple power conversion devices 14 by calculating multiple individual output control values based on the information on the output control value, the information on the multiple individual output powers, and the total value (step S106 in Figure 2).

[0065] As described above, in the output control device 12 according to this embodiment, when the control unit 42 is unable to acquire information on measurement values, the control unit 42 calculates the sum of the magnitudes of the power output from each of the multiple power conversion devices 14, and is able to continue output control of the multiple power conversion devices 14 based on the sum. The output control device 12 according to this embodiment can continue operation of the multiple power conversion devices 14 even when it is unable to acquire information on measurement values. This allows for more effective use of the power of each solar panel 2 (distributed power source). For example, it is possible to prevent the power generated by each solar panel 2 from being wasted. For example, it is possible to prevent losses in electricity sales revenue compared to when the operation of each power conversion device 14 is stopped when information on measurement values cannot be acquired.

[0066] In the above embodiment, a solar power generation system 10 in which solar panels 2 are used as distributed power sources is shown as an example of a distributed power generation system. The distributed power source is not limited to the solar panels 2, and may be, for example, a wind power generator or a geothermal power generator. The distributed power source may be, for example, a storage battery. In this case, each power conversion device 14 may further have a function of charging the storage battery based on power from the power grid 4. The distributed power source may be any power source capable of supplying power. The power supplied by the distributed power source is not limited to DC power, and may be AC power, for example. The distributed power generation system is not limited to the solar power generation system 10, and may be any system using any distributed power source.

[0067] The present embodiment includes the following aspects. (Appendix 1) An output control device that controls the output of a plurality of power conversion devices that output power supplied from a plurality of distributed power sources to a power grid, an information acquisition unit that acquires information on output control values that indicate the magnitude of power that is to be limited when output from the plurality of power electronics devices to the power grid, information on measurement values that measure the magnitude of power output from the plurality of power electronics devices to the power grid at interconnection points between the plurality of power electronics devices and the power grid, and information on a plurality of individual output powers that indicate the magnitude of power output from each of the plurality of power electronics devices; a control unit that calculates a plurality of individual output control values representing the magnitude of power to limit the output of each of the plurality of power electronics devices based on information on the output control value, information on the measurement value, and information on the plurality of individual output powers, and controls the outputs of the plurality of power electronics devices so that the magnitude of power output from the plurality of power electronics devices to the power grid corresponds to the output control values by causing each of the plurality of power electronics devices to output power of a magnitude corresponding to the plurality of individual output control values; Equipped with When the control unit cannot obtain the information on the measurement values, it calculates the total value of the magnitude of the power output from each of the multiple power conversion devices based on the information on the multiple individual output powers, and calculates the multiple individual output control values based on the information on the output control value, the information on the multiple individual output powers, and the total value, thereby enabling the output control of the multiple power conversion devices to be continued.

[0068] (Appendix 2) The output control device according to claim 1, wherein the control unit is capable of switching between control for continuing output control of the plurality of power conversion devices by calculating the sum value when information on the measurement value cannot be obtained, and control for stopping operation of the plurality of power conversion devices.

[0069] (Appendix 3) 3. The output control device according to claim 1, wherein, when the control unit is unable to acquire the information on the measurement value, the control unit issues a notification indicating that the information on the measurement value cannot be acquired.

[0070] (Appendix 4) The output control device according to any one of appendices 1 to 3, wherein the control unit adds a fixed value to the sum of the magnitudes of the power output from each of the plurality of power conversion devices in calculating the total value.

[0071] (Appendix 5) 5. The output control device according to claim 4, wherein the control unit receives input of fixed value information representing the magnitude of the fixed value, and is capable of changing the magnitude of the fixed value based on the fixed value information.

[0072] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0073] 2...Solar panel (distributed power supply), 4...Power system, 6...Power server, 10...Photovoltaic power generation system (distributed power supply system), 12...Output control device, 14...Power conversion device, 16, 18...Transformer, 20...Power receiving and substation equipment, 22...Wattmeter, 24...Monitoring device, 30...Converter, 32...Communication device, 40...Information acquisition unit, 42...Control unit

Claims

1. An output control device that controls the output of a plurality of power conversion devices that output power supplied from a plurality of distributed power sources to a power grid, an information acquisition unit that acquires information on output control values that indicate the magnitude of power that is to be limited when output from the plurality of power electronics devices to the power grid, information on measurement values that measure the magnitude of power output from the plurality of power electronics devices to the power grid at interconnection points between the plurality of power electronics devices and the power grid, and information on a plurality of individual output powers that indicate the magnitude of power output from each of the plurality of power electronics devices; a control unit that calculates a plurality of individual output control values representing the magnitude of power to limit the output of each of the plurality of power electronics devices based on information on the output control value, information on the measurement value, and information on the plurality of individual output powers, and controls the outputs of the plurality of power electronics devices so that the magnitude of power output from the plurality of power electronics devices to the power grid corresponds to the output control values by causing each of the plurality of power electronics devices to output power of a magnitude corresponding to the plurality of individual output control values; Equipped with When the control unit cannot obtain the information on the measurement values, it calculates the total value of the magnitude of the power output from each of the multiple power conversion devices based on the information on the multiple individual output powers, and calculates the multiple individual output control values based on the information on the output control value, the information on the multiple individual output powers, and the total value, thereby enabling the output control of the multiple power conversion devices to be continued.

2. The output control device according to claim 1, wherein the control unit is capable of switching between control of continuing output control of the plurality of power conversion devices by calculating the sum value when information on the measurement value cannot be obtained, and control of stopping operation of the plurality of power conversion devices.

3. The output control device according to claim 1 , wherein the control unit issues a notification indicating that the information on the measurement value cannot be acquired when the information on the measurement value cannot be acquired.

4. The output control device according to claim 1 , wherein the control unit adds a fixed value to the sum of the magnitudes of the power output from each of the plurality of power electronics devices in calculating the total value.

5. 5. The output control device according to claim 4, wherein the control unit receives fixed value information indicating the magnitude of the fixed value, and is capable of changing the magnitude of the fixed value based on the fixed value information.

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