Variable output power supply system control method and variable output power supply system

Abstract

To provide a control method for an output fluctuation power system, capable of suppressing an increase rate of an output fluctuation within a predetermined limit value and preventing the generation of excessive output suppression.SOLUTION: A control method for an output fluctuation electrical power system includes: one or more output fluctuation power sources; a controller for controlling the output fluctuation power source; and a power generation output detection section for detecting a power generation output of the output fluctuation power source. The controller stores a power generation output of an output fluctuation power source and when a prescribed period from the past to the present is taken as a first prescribed period and another prescribed period from the present to the future as a second prescribed period, obtains a minimum (for example, P0min) of a power generation output in the first prescribed period, computes the tolerance (for example, α0) of the second prescribed period against a predetermined limit value of the power generation output and takes a value (for example, P0min+α0) obtained by adding the tolerance to the minimum as a power generation output limit command in the second prescribed period.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a control method for a variable output power supply system using renewable energy, and to a variable output power supply system. [Background technology]

[0002] In recent years, global warming caused by increased carbon dioxide emissions and energy shortages caused by the depletion of fossil fuels have become issues. As a result, the introduction of power generation systems that use renewable energy obtained from nature, such as wind power, has been attracting attention as a power generation system that reduces carbon dioxide emissions and does not use fossil fuels.

[0003] Since renewable energy is a time-varying energy, the output of variable-output renewable energy sources also fluctuates over time. Power grids maintain the balance between supply and demand by adjusting the power output of large generators according to the level of power demand. When variable-output sources are connected to the power grid, there is concern that the large output fluctuations will lead to increased frequency fluctuations.

[0004] Here, for example, Patent Document 1 discloses a method for mitigating output fluctuations in a wind power generation system. Patent Document 1 discloses that in a wind power generation system having a wind power generation device group consisting of one or more wind power generation devices and a power storage system consisting of one or more power storage devices, the wind power generation system includes an output power recording means for recording an output power that is the sum of the power generated by the wind power generation device group and the charge / discharge power of the power storage system, and a generated power detection unit for detecting the power generated by the wind power generation device group, and that, assuming that a predetermined period from the past to the present is a first period and another predetermined period from the present to the future is a second period, the wind power generation system includes a charge / discharge power command calculation means for calculating a charge / discharge power command for the storage battery system for the second period using information on the output power for the first period recorded in the output power recording means and information on the current detection value of the generated power detection unit, and a charge / discharge power control means for controlling the charge / discharge power according to the charge / discharge power command in the power storage system. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2009-79559 [Non-patent literature]

[0006] [Non-Patent Document 1] "Grid Code (Technical Requirements for Grid Interconnection)," Agency for Natural Resources and Energy, Ministry of Economy, Trade and Industry, January 16, 2020 Summary of the Invention [Problem to be solved by the invention]

[0007] As disclosed in Non-Patent Document 1, in order to avoid adverse effects due to output fluctuations, it is desirable to suppress the increase in output fluctuation (the rate of increase in output fluctuation) to a predetermined constant limit value (for example, within 10% of the rated value of the output fluctuation power supply) for a certain period (for example, within 5 minutes) starting from an arbitrary time.

[0008] As disclosed in Patent Document 1, it is possible to suppress the rate of increase in output fluctuation of a variable output power source by using an apparatus configuration in which a power storage system is used in combination with a variable output power source.

[0009] Furthermore, among variable output power sources, wind power generation systems often have a function that controls the rate of increase in output fluctuation from moment to moment to a constant value. This function makes it possible to suppress the rate of increase in output fluctuation within a limit value.

[0010] However, not all variable output power sources are equipped with energy storage systems. In addition, if the rate of increase in output fluctuation is set to a constant value using conventional control functions, power generation output will be limited even if there is a sufficient margin above the limit within a specified period, resulting in excessive output suppression.

[0011] The present invention is an invention for solving the above-mentioned problems, and has an object to provide a control method for a variable output power supply system and a variable output power supply system that suppresses the rate of increase of output fluctuation within a predetermined limit value and prevents excessive output suppression. [Means for solving the problem]

[0012] In order to achieve the above-mentioned object, the present invention provides a control method for a variable output power supply system comprising one or more variable output power supplies, a controller for controlling the variable output power supplies, and a power generation output detection unit for detecting the power generation output of the variable output power supply, wherein the controller stores the power generation output of the variable output power supply, and, assuming that a predetermined period from the past to the present is a first predetermined period and another predetermined period from the present to the future is a second predetermined period, determines a minimum value of the power generation output during the first predetermined period, calculates a tolerance for the second predetermined period with respect to a predetermined limit value of the power generation output, and sets a value obtained by adding the tolerance to the minimum value as a power generation output limit command for the second predetermined period. With respect to control during the second predetermined period after the current time has passed, the controller recalculates the margin during the second predetermined period based on a difference between the power generation output up to the elapsed time during the second predetermined period and a predetermined limit value of the power generation output based on the minimum value during the first predetermined period, and sets a value obtained by adding the recalculated margin to the minimum value during the first predetermined period as a power generation output limit command for the remaining time during the second predetermined period. Other aspects of the present invention will be described in the embodiments described later. Effect of the Invention

[0013] According to the present invention, it is possible to suppress the rate of increase in output fluctuation to within a predetermined limit value and prevent excessive output suppression. [Brief description of the drawings]

[0014] [Figure 1] 1 is a configuration diagram showing a wind power generation system according to a first embodiment. [Diagram 2] 1 is a configuration diagram showing a wind turbine generator according to a first embodiment. [Diagram 3] FIG. 2 is a block diagram showing the processing of a controller of the wind turbine generator according to the first embodiment. [Figure 4] FIG. 2 is a block diagram showing the processing of a host controller according to the first embodiment. [Diagram 5]FIG. 4 is a schematic diagram showing the relationship between power generation output before and after control according to the first embodiment. [Figure 6] FIG. 4 is an explanatory diagram showing power generation control command values ​​when the current time is t-6 minutes according to the first embodiment. [Figure 7] FIG. 4 is an explanatory diagram showing power generation control command values ​​when the current time is t-3 minutes according to the first embodiment. [Figure 8] 4 is an explanatory diagram showing power generation control command values ​​when the current time is t+1 minutes according to the first embodiment. FIG. [Figure 9] FIG. 11 is a block diagram showing the processing of a host controller according to the second embodiment. [Figure 10] FIG. 11 is a block diagram showing the processing of a host controller according to the third embodiment. [Figure 11] FIG. 13 is a schematic diagram showing the relationship between the power generation output before and after control at ti minutes according to the third embodiment. [Figure 12] FIG. 13 is a block diagram showing the processing of a host controller according to the fourth embodiment. [Figure 13] FIG. 13 is a block diagram showing the processing of a host controller according to the fifth embodiment. [Figure 14] FIG. 13 is a schematic diagram showing the relationship between the power generation output before and after control at ti minutes according to the fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment for carrying out the present invention will be described in detail with reference to the accompanying drawings. For the sake of detailed description, a variable output power source will be described using a wind power generation system as an example. Note that the same components in each drawing are denoted by the same reference numerals, and detailed description of overlapping parts will be omitted.

[0016] First Embodiment FIG. 1 is a configuration diagram showing a wind power generation system 100 according to a first embodiment. The overall schematic configuration of the wind power generation system 100 will be described with reference to FIG. 1. The wind power generation system 100 of the present invention is composed of one or more wind power generation devices 1, a SCADA (Supervisory Control And Data Acquisition) 2, and a host controller 3. The SCADA 2 is responsible for collecting operation information such as the operating status and power generation output of the wind power generation system 100. Furthermore, the SCADA 2 receives a limit command (WF power generation output limit command) of the power generation output of the wind power generation system 100 from the host controller 3, and issues a limit command 1, a limit command 2, . . . , and a limit command n to each wind power generation device 1 so that the sum of the power generation outputs (WF power generation output) of each wind power generation device 1 is equal to or less than a predetermined limit value. Here, the configuration of this embodiment is not limited to FIG. 1, and it can be realized even if the SCADA 2 also has a part or the whole function of the host controller 3. Similarly, it can be realized even if the host controller 3 has a part or the whole function of the SCADA 2. The upper controller 3 acquires the power generation output from the power generation output detector 37.

[0017] FIG. 2 is a configuration diagram showing a wind turbine generator 1 according to a first embodiment. Details of the wind turbine generator 1 will be described with reference to FIG. 2. The wind turbine generator 1 includes a rotor 6 including a plurality of blades 4 and a hub 5 connecting the plurality of blades 4. The rotor 6 is connected to a nacelle 7 via a rotating shaft (omitted in FIG. 2), and the position of the blades 4 can be changed by rotating the rotor 6. The nacelle 7 rotatably supports the rotor 6. The rotor 6 rotates when the blades 4 catch wind, and the rotational force of the rotor 6 rotates a generator 8 in the nacelle 7, thereby generating electricity. A wind direction and speed sensor 9 for measuring wind direction and speed is provided on the nacelle 7.

[0018] Each blade 4 is equipped with a pitch angle drive device 10 capable of adjusting the angle (pitch angle) of the blade 4 relative to the wind. By changing the pitch angle using the pitch angle drive device 10, the wind force (wind volume) received by the blade 4 can be adjusted, and the rotational energy of the rotor 6 relative to the wind can be changed. This makes it possible to control the rotational speed and generated power over a wide range of wind speeds.

[0019] In the wind turbine generator 1, the nacelle 7 is installed on the tower 11, and has a mechanism (not shown in the figure) that allows it to rotate with respect to the tower 11. The tower 11 supports the load of the blades 4 via the hub 5 and the nacelle 7, and is fixed to a base (not shown in the figure) that is installed at a predetermined position on the ground, offshore, or on a floating body.

[0020] The torque generated by the generator 8 (hereinafter referred to as generator torque) is controlled by a power converter 12 installed in the tower 11, for example, so that the rotational torque of the rotor 6 can be controlled.

[0021] 3 is a block diagram showing the processing of the controller 13 of the wind turbine generator 1 according to the first embodiment. The wind turbine generator 1 includes the controller 13, which calculates a generator torque command value and a pitch angle command value based on the rotation speed output from a rotation speed sensor 14 that measures the rotation speed of the generator 8 and the generator torque of the generator 8, and adjusts the generator 8 and the pitch angle driver 10 to adjust the generated power and the rotation speed of the wind turbine generator 1.

[0022] 4 is a block diagram showing the processing of the upper controller 3 according to the first embodiment. The upper controller 3 has a WF power generation output storage unit 31 that stores the power generation output from the power generation output detection unit 37 (see FIG. 1), a WF power generation output minimum value calculation unit 32 that calculates the minimum value of the power generation output in the first predetermined period stored in the WF power generation output storage unit 31, where a predetermined period from the past to the present is defined as a first predetermined period and another predetermined period from the present to the future is defined as a second predetermined period, and a WF limit command calculation unit 33 that calculates the margin of the second predetermined period with respect to a predetermined limit value of the power generation output and adds the calculated margin to the minimum value to obtain a power generation output limit command for the second predetermined period.

[0023] The upper controller 3 calculates a minimum value Pmin of the WF power generation output from the WF power generation output stored in the WF power generation output storage unit 31 using the WF power generation output minimum value calculation unit 32, and calculates a WF power generation output limit command by adding the margin α0 calculated in the WF power generation output margin calculation unit 34 to Pmin in the WF limit command calculation unit 33. The WF power generation output storage unit 31 stores the past WF power generation output for a certain period from the current time in an internal memory. The WF power generation output minimum value calculation unit 32 calculates the minimum value of the WF power generation output for a certain period from the current time.

[0024] Here, the WF power generation output used in the WF power generation output storage unit 31 and the WF power generation output minimum value calculation unit 32 may be an instantaneous value, a value filtered by an arbitrary time constant, a moving average value, or an average value or median value for an arbitrary period. The margin α0 calculated in the WF power generation output margin calculation unit 34 is a value determined based on the limit value of the rate of increase of the output fluctuation, and may be determined by analysis or simulation, or may be adjusted by trial and error using an actual device. The WF power generation output limit command may be a value at the current time or a value at a future time.

[0025] Fig. 5 is a schematic diagram showing the relationship between the power generation output before and after the control according to the first embodiment. Fig. 5 shows an overview of the power generation output when the control according to this embodiment is not implemented and when it is implemented. Fig. 5 is a diagram for explaining that the rate of increase in the output fluctuation over a certain period (5 minutes) is suppressed to an arbitrary certain limit value (10% of the rated value of the wind power generation system) or less. Here, for example, the first and second predetermined periods are each set to 5 minutes.

[0026] As shown in FIG. 5, when the current time is t-5 minutes, going back for example 5 minutes from the present, the minimum value is P0min. That is, if the minimum value Pmin is measured at t-5 minutes, the pre-limit WF power output needs to be suppressed to the limit value P0min+10% or less until t minutes. Since the WF power output also fluctuates over time due to temporal fluctuations in wind energy, the upper controller 3 determines the WF power output limit command by adding a margin α0 that takes into account the fluctuation (variance) of the WF power output to P0min. This makes it possible to suppress the post-limit WF power output to P0min+10% or less even if the WF power output fluctuates with respect to the WF power output limit command. In this case, the margin α0 is calculated to be a value between P0min and P0min+10%.

[0027] The concept of the WF power generation output limit command shown in FIG. 5 will be described with reference to FIGS. 6 is an explanatory diagram showing the power generation control command value when the current time is t-6 minutes according to the first embodiment. When the current time is t-6 minutes, going back 5 minutes from the present (the period from t-11 minutes to t-6 minutes), for example, the minimum value is P1min, and therefore the power generation control command value is P1min+α0.

[0028] 7 is an explanatory diagram showing the power generation control command value when the current time is t-3 minutes according to the first embodiment. When the current time is t-3 minutes, going back 5 minutes from the present (the period from t-8 minutes to t-3 minutes), for example, the minimum value is P0min, so the command value is P0min+α0.

[0029] 8 is an explanatory diagram showing the power generation control command value when the current time is t+1 minutes according to the first embodiment. When the current time is t+1 minutes, going back 5 minutes from the present (the period from t-4 minutes to t+1 minutes), for example, the minimum value is P2min, so the command value is P2min+α0.

[0030] In this embodiment, the arbitrary fixed period is described as 5 minutes and the arbitrary fixed limit value is described as 10%, but the effect of this embodiment can be similarly achieved even if these values ​​are changed according to the power system.

[0031] In this embodiment, the description is limited to a wind power generation system, but it is also possible to apply the present invention to a power generation system using natural energy such as a solar power generation system or a wave power generation system. When the first embodiment is applied, it is possible to suppress the rate of increase in output fluctuation within an arbitrary fixed limit value and to reduce excessive output suppression within an arbitrary fixed period.

[0032] <Second embodiment> Fig. 9 is a block diagram showing the processing of the upper controller 3A according to the second embodiment. The upper controller 3A of the second embodiment is different from the upper controller 3 of the first embodiment in that a WF power generation output dispersion calculation unit 51 is added. The second embodiment will be described with reference to Fig. 9. Descriptions of parts that overlap with the first embodiment will be omitted.

[0033] As shown in FIG. 9, unlike the first embodiment, the upper controller 3A calculates the margin α0 in the WF power output margin calculation unit 34 based on the variance calculated by the WF power output variance calculation unit 51. The WF power output variance calculation unit 51 calculates the variance based on the wind speed, wind direction, turbulence intensity, yaw error, pitch angle, rotation speed, the number of wind power generation devices 1 in power generation operation, and the WF power output limit command, using a table or function calculated by a pre-analysis or simulation, or a model constructed by a machine learning method using operation record data. The variance is a parameter held in a table, function, or machine learning model in consideration of the fluctuation of the WF power output in response to the WF power output limit command, and can be determined by utilizing various statistical models, the minimum and maximum change width of the fluctuation, or an arbitrary percentile value. For example, when a normal distribution is assumed, a value such as 2σ or 3σ can be determined as the variance.

[0034] The tolerance α0 for this variance is calculated based on a table or function stored in the WF power output tolerance calculation unit 34. Here, the input values ​​used by the WF power output variance calculation unit 51 may be all of the wind speed, wind direction, turbulence intensity, yaw error, pitch angle, rotation speed, number of wind power generation devices in power generation operation, and WF power output limit command, or any combination of these. The input values ​​may be instantaneous values, values ​​filtered using an arbitrary time constant, moving average values, or average values ​​over an arbitrary period. The input values ​​may be values ​​of each wind power generation device 1 of the wind power generation system 100, or any value, or a representative value such as an average value or a median value.

[0035] The reason why each of the above input values ​​becomes a factor of power generation output fluctuation (dispersion) will be explained. (1) Wind speed: When wind speed changes, the input energy to the wind turbine changes, causing fluctuations in power generation output. In particular, the lower the wind speed, the stronger the degree of turbulence tends to be. (2) Wind direction: This is because the power output fluctuates due to differences in wind conditions caused by the relative positions of the wind turbines and the influence of the terrain. For example, when the wind direction comes from mountainous terrain, the wind conditions fluctuate greatly, but when the wind direction comes from flat land, the wind conditions fluctuate less than when it comes from mountains. In addition, in the case of a wind farm, wind conditions fluctuate depending on the wind direction due to the influence of wakes from the operation of other wind turbines. (3) Turbulence intensity: Turbulence intensity indicates the degree of turbulence in wind conditions. Changes in turbulence intensity cause changes in wind conditions, which in turn cause fluctuations in power generation output. Generally, the greater the turbulence intensity, the greater the wind conditions fluctuations. (4) Yaw error: This is the deviation between the wind direction and the rotor shaft angle, and indicates how far the rotor shaft is deviated from the wind direction. If the yaw error changes, the input energy to the wind turbine changes, causing the power output to fluctuate. (5) Pitch angle: Changes in the pitch angle change the power generation efficiency, which causes fluctuations in power generation output. (6) Rotational speed: Changes in rotational speed cause changes in power generation efficiency, resulting in fluctuations in power output. (7) Number of units in operation: The more the number of units in operation, the more the smoothing effect on the WF power output will be, and the fluctuations in the power output will be mitigated. This is because the fluctuation component of the power output will change depending on the number of units in operation. (8) WF power output limit command: When the WF power output limit command changes, the pitch angle and rotation speed change accordingly. This causes a change in power generation efficiency, which in turn causes the power output to fluctuate.

[0036] In this embodiment, the description is limited to a wind power generation system, but the present invention can also be applied to power generation systems that use natural energy, such as a solar power generation system and a wave power generation system.

[0037] In the case of a solar power generation system, the amount of solar radiation, weather, temperature, atmospheric pressure, season, humidity, etc. can be used as input values ​​to the WF power generation output variance calculation unit 51. In the case of a wave power generation system, the wave height, period, etc. can be used as input values ​​to the WF power generation output variance calculation unit 51.

[0038] When the second embodiment is applied, by appropriately taking into account the variance due to fluctuations in natural energy, it is possible to suppress the rate of increase in output fluctuations within an arbitrary fixed limit value and reduce excessive suppression of power generation output.

[0039] <Third embodiment> Fig. 10 is a block diagram showing the processing of a host controller 3B according to the third embodiment. The host controller 3B of the third embodiment is configured by adding an adjustment unit 61 to the host controller 3 of the first embodiment. The third embodiment will be described with reference to Fig. 10. Descriptions of parts that overlap with the first and second embodiments will be omitted.

[0040] As shown in Figure 10, the upper controller 3B calculates α1 in an adjustment unit 61 based on the margin α0 calculated by the WF power generation output margin calculation unit 34, the WF power generation output from the WF power generation output memory unit 31, and Pmin from the WF power generation output minimum value calculation unit 32.

[0041] Specifically, the adjustment unit 61 evaluates the difference between the WF power generation output and Pmin + a fixed limit value (e.g., 10%), and calculates α1 based on the evaluation result. Therefore, if the Pmin + a fixed limit value has not been reached, α is adjusted to be larger, and if the Pmin + a fixed limit value is reached, α is adjusted to be smaller. Here, the WF power generation output may be the current time or may be from the present to the past, and the time going back to the past can be set arbitrarily. In addition, the WF power generation output for evaluating the difference can also be processed to be the maximum value, average value, median value, or variance.

[0042] FIG. 11 is a schematic diagram showing the relationship between the power generation output before and after control at ti minutes according to the third embodiment. A specific operation will be described with reference to FIG. 11. As shown in FIG. 11, when controlling with the WF power generation output limit command P0min+α0 from t-5 minutes to ti minutes, it can be seen that there is a margin before reaching Pmin+10%. Therefore, the difference between the WF power generation output from t-5 minutes to ti minutes and P0min+10% is evaluated, and α1 is calculated in the adjustment unit 61 based on the evaluation result, and P0min+α1 is set as a new limit command value from ti minutes. This allows control close to P0min+10%, reducing excessive output suppression.

[0043] That is, with regard to control during the second specified period after the current time (the time marking the dividing line between the first and second specified periods), the upper controller 3B recalculates the margin during the second specified period based on the difference between the power generation output up to the elapsed time during the second specified period and a predetermined limit value (e.g., P0min+10%) of the power generation output based on the minimum value during the first specified period, and sets the value (e.g., P0min+α1) obtained by adding the recalculated margin (e.g., α1) to the minimum value during the first specified period (e.g., P0min) as the power generation output limit command for the remaining time during the second specified period.

[0044] In this embodiment, the description is limited to a wind power generation system, but the present invention can also be applied to power generation systems that use natural energy, such as a solar power generation system and a wave power generation system.

[0045] When the third embodiment is applied, by appropriately adjusting the tolerance based on the WF power generation output, it is possible to suppress the rate of increase in output fluctuation within an arbitrary fixed limit value and reduce excessive power generation output suppression.

[0046] <Fourth embodiment> Fig. 12 is a block diagram showing the processing of the upper controller 3C according to the fourth embodiment. The upper controller 3C of the fourth embodiment is different from the upper controller 3B of the third embodiment in that a WF power generation output dispersion calculation unit 51 is added. The fourth embodiment will be described with reference to Fig. 12. Descriptions of parts that overlap with the first, second, and third embodiments will be omitted.

[0047] As shown in FIG. 12, the upper controller 3C includes a WF power generation output variance calculation unit 51 (see FIG. 9), a WF power generation output margin calculation unit 34 (see FIG. 9), and an adjustment unit 61 (see FIG. 10) described in the first to third embodiments.

[0048] In this embodiment, the description is limited to a wind power generation system, but the present invention can also be applied to power generation systems that use natural energy, such as a solar power generation system and a wave power generation system.

[0049] When the fourth embodiment is applied, by appropriately taking into account the variance due to fluctuations in natural energy and adjusting the margin based on the WF power generation output, it is possible to suppress the rate of increase in output fluctuation within an arbitrary fixed limit value and reduce excessive suppression of power generation output.

[0050] <Fifth embodiment> Fig. 13 is a block diagram showing the processing of a host controller 3D according to the fifth embodiment. The host controller 3D of the fifth embodiment is different from the host controller 3C of the fourth embodiment in that a command value correction unit 91 is added. The fifth embodiment will be described with reference to Fig. 13. Descriptions of parts that overlap with the first to fourth embodiments will be omitted.

[0051] As shown in Fig. 13, the upper controller 3D includes a command value correction unit 91 that calculates a WF power generation output limit command by feedback control based on the difference between P0min+α1 and the WF power generation output. Here, the value obtained by feedback control may be the WF power generation output limit command, or may be a value limited by an upper and lower limiter of any value. For example, it is possible to set the lower limit to P0min and the upper limit to P0min+10. When the upper and lower limiters are applied, it is also possible to apply anti-windup control.

[0052] FIG. 14 is a schematic diagram showing the relationship between the power generation output before and after control at ti minutes according to the fifth embodiment. A specific operation will be described with reference to FIG. 14. When the WF power generation output is controlled to P0min+α1 from ti minutes to t minutes, it can be confirmed that the limited WF power generation output_before correction cannot be controlled to P0min+α1 and exceeds P0min+10% before correction by the command value correction unit 91. This is due to the effect of an offset that is generally seen in open-loop control. In order to remove this effect, the command value correction unit 91 corrects the WF power generation output limit command_after correction as the WF power generation output limit command, so that the limited WF power generation output_after correction can be controlled to P0min+α1.

[0053] That is, with regard to control during the second specified period after the current time (the dividing time between the first and second specified periods) has passed, the upper controller 3D makes a correction to reduce the recalculated tolerance through feedback control based on the difference between the power generation output and a value (e.g., P0min+α1) obtained by adding the recalculated tolerance to the minimum value during the first specified period, and sets the value (e.g., P0min+α2) obtained by adding the corrected value (e.g., α2) to the minimum value during the first specified period (e.g., P0min) as the power generation output limit command for the remaining time during the second specified period.

[0054] In this embodiment, the description is limited to a wind power generation system, but the present invention can also be applied to power generation systems that use natural energy, such as a solar power generation system and a wave power generation system.

[0055] When the fifth embodiment is applied, by correcting the WF power generation output limit command based on feedback control, it is possible to suppress the rate of increase in output fluctuation within an arbitrary fixed limit value and reduce excessive power generation output suppression.

[0056] The present invention is not limited to the above-described embodiment, but includes various modified examples. For example, the above-described embodiment has been described in detail to clearly explain the present invention, and is not necessarily limited to those including all of the configurations described. In addition, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. In addition, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration. [Explanation of symbols]

[0057] 1. Wind power generation equipment 2. SCADA 3, 3A, 3B, 3C, 3D Upper controller (controller) 4 Blades 5 Hub 6 Rotor 7 Nacelle 8. Generator 9 Wind Speed ​​Sensor 10 Pitch angle drive unit 11. Tower 12 Power Converter 13 Controller 14 Rotational speed sensor 31 WF power generation output memory unit (power generation output memory unit) 32 WF power generation output minimum value calculation unit (power generation output minimum value calculation unit) 33 WF limit command calculation unit (limit command calculation unit) 34 WF power output margin calculation section 51 WF power generation output distribution calculation section 61 Adjustment section 91 Command value correction section

Claims

1. A method for controlling a variable output power supply system having one or more variable output power supplies, a controller for controlling the variable output power supplies, and a power generation output detection unit for detecting a power generation output of the variable output power supplies, comprising the steps of: The controller stores the power generation output of the variable output power source, A predetermined period from the past to the present is defined as a first predetermined period, and another predetermined period from the present to the future is defined as a second predetermined period. A minimum value of the power generation output during the first predetermined period is calculated. calculating a margin for a second predetermined period with respect to a predetermined limit value of the power generation output, and setting a value obtained by adding the margin to the minimum value as a power generation output limit command for the second predetermined period; With respect to control during the second predetermined period after the current time has elapsed, The controller recalculates the margin during the second predetermined period based on a difference between a power generation output up to an elapsed time during the second predetermined period and a predetermined limit value of the power generation output based on a minimum value during the first predetermined period, and sets a value obtained by adding the recalculated margin to the minimum value during the first predetermined period as a power generation output limit command for the remaining time during the second predetermined period. A method for controlling a variable output power supply system comprising:

2. 2. A method for controlling a variable output power supply system according to claim 1, comprising: The controller corrects the recalculated margin by reducing the recalculated margin during the remaining time of the second predetermined period through feedback control based on a difference between the power generation output and a value obtained by adding the recalculated margin to the minimum value during the first predetermined period, and sets the value obtained by adding the corrected value to the minimum value during the first predetermined period as a power generation output limit command during the remaining time of the second predetermined period. A method for controlling a variable output power supply system comprising:

3. A method for controlling a variable output power supply system having one or more variable output power supplies, a controller for controlling the variable output power supplies, and a power generation output detection unit for detecting a power generation output of the variable output power supplies, comprising the steps of: The controller stores the power generation output of the variable output power source, A predetermined period from the past to the present is defined as a first predetermined period, and another predetermined period from the present to the future is defined as a second predetermined period. A minimum value of the power generation output during the first predetermined period is calculated. calculating a margin for a second predetermined period with respect to a predetermined limit value of the power generation output, and setting a value obtained by adding the margin to the minimum value as a power generation output limit command for the second predetermined period; the variable output power supply system is a wind power generation system, The controller calculates a variance value of output fluctuation based on at least one of information of wind speed, wind direction, turbulence intensity, yaw error, pitch angle, rotational speed of a rotor or generator, number of generators in power generation, and power generation output limit command value, and calculates the margin based on the variance value. A method for controlling a variable output power supply system comprising:

4. A method for controlling a variable output power supply system according to any one of claims 1 to 3, comprising the steps of: The power generation output during the first predetermined period is calculated as any one of an instantaneous value, an average value, a median value, a moving average value, and a value filtered using a predetermined time constant. A method for controlling a variable output power supply system comprising:

5. A variable output power supply system having one or more variable output power supplies, a controller for controlling the variable output power supplies, and a power generation output detection unit for detecting a power generation output of the variable output power supplies, The controller includes a power generation output storage unit that stores a power generation output of the variable output power source; a power generation output minimum value calculation unit that calculates a minimum value of the power generation output during a first predetermined period stored in the power generation output storage unit, where a predetermined period from the past to the present is defined as a first predetermined period and another predetermined period from the present to the future is defined as a second predetermined period; a limit command calculation unit that calculates a margin for a second specified period with respect to a predetermined limit value of the power generation output, and sets a value obtained by adding the margin to the minimum value as a power generation output limit command for the second specified period, The limit command calculation unit recalculates the margin during the second predetermined period based on a difference between a power generation output up to an elapsed time during the second predetermined period and a predetermined limit value of the power generation output based on a minimum value during the first predetermined period, and sets a value obtained by adding the recalculated margin to the minimum value during the first predetermined period as a power generation output limit command for the remaining time during the second predetermined period. A variable output power supply system comprising:

6. A variable output power supply system having one or more variable output power supplies, a controller for controlling the variable output power supplies, and a power generation output detection unit for detecting a power generation output of the variable output power supplies, The controller includes a power generation output storage unit that stores a power generation output of the variable output power source; a power generation output minimum value calculation unit that calculates a minimum value of the power generation output during a first predetermined period stored in the power generation output storage unit, where a predetermined period from the past to the present is defined as a first predetermined period and another predetermined period from the present to the future is defined as a second predetermined period; a limit command calculation unit that calculates a margin for a second specified period with respect to a predetermined limit value of the power generation output, and sets a value obtained by adding the margin to the minimum value as a power generation output limit command for the second specified period, The limit command calculation unit recalculates the margin during the second specified period based on a difference between a power generation output up to an elapsed time during the second specified period and a predetermined limit value of the power generation output based on a minimum value during the first specified period, corrects the recalculated margin to reduce the margin during the remaining time during the second specified period by feedback control based on a difference between the power generation output and a value obtained by adding the recalculated margin to the minimum value during the first specified period, and sets the value obtained by adding the corrected value to the minimum value during the first specified period as a power generation output limit command for the remaining time during the second specified period. A variable output power supply system comprising:

7. A variable output power supply system having one or more variable output power supplies, a controller for controlling the variable output power supplies, and a power generation output detection unit for detecting a power generation output of the variable output power supplies, The controller includes a power generation output storage unit that stores a power generation output of the variable output power source; a power generation output minimum value calculation unit that calculates a minimum value of the power generation output during a first predetermined period stored in the power generation output storage unit, where a predetermined period from the past to the present is defined as a first predetermined period and another predetermined period from the present to the future is defined as a second predetermined period; a limit command calculation unit that calculates a margin for a second specified period with respect to a predetermined limit value of the power generation output, and sets a value obtained by adding the margin to the minimum value as a power generation output limit command for the second specified period, the variable output power supply system is a wind power generation system, The controller calculates a variance value of output fluctuation based on at least one of information of wind speed, wind direction, turbulence intensity, yaw error, pitch angle, rotational speed of a rotor or generator, number of generators in power generation, and power generation output limit command value, and calculates the margin based on the variance value. A variable output power supply system comprising:

8. 8. The variable output power supply system according to claim 5, The power generation output during the first predetermined period is calculated as any one of an instantaneous value, an average value, a median value, a moving average value, and a value filtered using a predetermined time constant. A variable output power supply system comprising:

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