Control unit of wind power generation device, wind power generation device, control method of wind power generation device, control program and storage medium

Abstract

A control unit controls the power generation output of a wind power generation device, the wind power generation device including a windmill and a generator that generates power by rotating a rotor of the windmill. The control unit has a rated output mode for controlling the power generation output of the generator to be a rated value, and is configured to perform a temporary power generation output increase process when the rotor speed of the windmill in the rated output mode is in a state of decreasing by a predetermined rotor speed, the temporary power generation output increase process having a first control of decreasing the torque applied to the generator to suppress the decrease in the rotor speed, and a second control of increasing the torque to temporarily increase the power generation output in a state where the decrease in the rotor speed is suppressed.

Description

Technical Field

[0001] The present disclosure relates to a control unit of a wind power generation device that controls power generation output and operates, a wind power generation device, a control method of a wind power generation device, a control program, and a storage medium. Background Art

[0002] In a wind turbine generator, power generation output is controlled by adjusting the pitch control of the wind turbine blade installation angle, changing the orientation of the wind turbine through yaw control, and torque control of the generator. Usually, a rated output is set as a target, and rated output control is performed with this rated output as the target.

[0003] In this rated output control, when the wind speed is higher than the rated wind speed and exceeds the rated output, pitch control is used to prevent the windmill's rotor speed from exceeding the rated rotor speed. When the wind speed is higher than the rated wind speed but lower than the rated output, pitch control and torque control are used to prevent the windmill's rotor speed from falling below the rated rotor speed. More efficient control is expected.

[0004] For example, in Patent Document 1, when the mechanical load of the wind turbine decreases, a rotor rotation speed adjustment program is started. In the rotor rotation speed adjustment program, an adjustment rotor rotation speed setting value greater than an initial rotor rotation speed setting value is determined, and the maximum rotor rotation speed setting value of the wind turbine is increased, thereby increasing the energy capture amount.

[0005] Furthermore, in Patent Document 2, when the wind speed is above a first wind speed for achieving rated power generation output, the rotor rotation speed is maintained at the rated value, and when the wind speed is less than the first wind speed and above a second wind speed for the rotor rotation speed to reach the rated rotor rotation speed, a first operating mode in which a target value of the rotor rotation speed, i.e., a rotor rotation speed target value, is increased to a value greater than the rated rotor rotation speed as the wind speed increases, and a second operating mode in which the rotor rotation speed target value is reduced from a value greater than the rated rotor rotation speed to the rated rotor rotation speed as the wind speed increases can be executed.

[0006] Prior Art Literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2009-287564

[0009] Patent Document 2: Japanese Patent Application Publication No. 2018-119427 Summary of the invention

[0010] Problems to be solved by the invention

[0011] The technology of Patent Document 1 can increase the rated power generation output of the wind power generation system and obtain a greater power generation output, but there are the following issues: various elements including motor equipment including generators and power converters will operate above the rated power generation output, and when a load higher than the original design value is applied, their capacity, etc. needs to have a large margin, etc.

[0012] Furthermore, the technology of Patent Document 2 is a method of increasing the target rotor speed when the rotor speed of the wind turbine has not reached the rated rotor speed, and the rotor speed will temporarily (instantaneously) exceed the rated rotor speed, so there is a possibility of applying a load exceeding the initial design. Furthermore, when the wind turbine generator is installed in a mountainous area, the wind speed changes due to the complex terrain, resulting in a large change in the rotor speed.

[0013] As described above, in Patent Documents 1 and 2, in order to obtain a higher power generation, the target rotor speed is temporarily set higher to achieve an increase in power generation. In a general wind power generation device, when the rotor speed exceeds a constant allowable value (threshold), the windmill is emergency stopped from the perspective of protecting the windmill device. The method of increasing the target rotor speed may induce an over-rotation state, resulting in a decrease in the operating rate of the windmill, which is not ideal in terms of operation.

[0014] Figure 3 The relationship between the rotor speed and the set torque is shown in Figure 3 , a control value of a normal set torque is shown. Usually, the set torque is applied in proportion to the square of the rotor speed, so that the aerodynamic characteristics of the wind turbine rotor can be kept optimal, and the rotor speed follows the set torque (optimum torque curve) when the rotor speed is low.

[0015] On the other hand, in generators and other equipment, there are limitations on the rotor speed and torque for device protection. Because of this limitation, it is difficult to maintain the optimal torque curve at all rotor speeds. Therefore, the rated rotor speed and rated torque are set according to the requirements of the equipment such as the generator. The power generation output at this setting is called the rated output. In addition, the wind speed that achieves the rated output is called the rated wind speed. The rated rotor speed and the maximum rotor speed that can maintain the optimal torque curve usually diverge, resulting in a range where the torque increases sharply.

[0016] Here, in the conventional control device, the rotor speed range that can generate electricity is widened along the optimal torque curve, thereby controlling the power generation output in a manner that increases. However, the rotor speed of a general device has an upper limit for device protection. Moreover, in the conventional control, the case where the wind speed increases over time is particularly shown, and the setting when the wind speed decreases is not described. The conventional control when the wind speed decreases can be considered to be in accordance with the conventional torque control (corresponding to Figure 3 Therefore, when the motor is operated between the rated rotor speed and the maximum rotor speed that can maintain the optimal torque curve, a decrease in power generation efficiency is inevitable.

[0017] The present disclosure aims to provide a control method that can suppress a decrease in generated power generation under conditions of temporally varying wind speeds, particularly when a wind turbine generator is operated near a rated rotor speed and the wind speed decreases (temporarily) over time.

[0018] Solutions to Solve Problems

[0019] A control unit of one scheme of the present disclosure is a control unit for controlling the power generation output of a wind power generation device, wherein the wind power generation device includes a windmill and a generator that generates electricity by rotating the rotor of the windmill, the control unit having a rated output mode for controlling the power generation output of the generator in such a manner that the power generation output becomes a rated value, the control unit being configured to perform a temporary power generation output increase process when the rotor speed of the windmill in the rated output mode is in a state of decreasing a predetermined rotor speed, the temporary power generation output increase process having a first control for reducing the torque applied to the generator to suppress the decrease in the rotor speed, and a second control for subsequently increasing the torque to temporarily increase the power generation output in a state where the decrease in the rotor speed is suppressed.

[0020] Furthermore, the control unit may be configured to perform pitch control for changing an attachment angle of blades of the wind turbine.

[0021] Furthermore, the control unit may be capable of setting the pitch control to a control different from a normal pitch control during execution of the temporary power generation output increase process.

[0022] Furthermore, the state in which the rotor speed is reduced by a predetermined amount may be a state in which the rotor speed is reduced by a predetermined amount or by a predetermined ratio relative to the rotor speed in the rated output mode.

[0023] Furthermore, it is possible that the state of decreasing the predetermined rotor speed is determined by a value of a pitch angle.

[0024] Furthermore, the state in which the rotor speed is reduced by a predetermined amount may be a state in which the rated output is reduced for a predetermined time.

[0025] Furthermore, it is possible that the time for performing the first control is predetermined.

[0026] Furthermore, the control unit may perform control to return to normal control after a predetermined standby time has elapsed after executing the temporary power generation output increase process.

[0027] Furthermore, the decrease in the rotor speed may be suppressed by at least any one of reducing the amount of decrease in the rotor speed, maintaining the rotor speed, or increasing the rotor speed.

[0028] Furthermore, the reduction of the torque in the first control may be performed in accordance with a decrease in a target power generation output.

[0029] Furthermore, the second control may be performed so as to increase the torque in accordance with a target power generation output equal to or lower than a rated output mode.

[0030] Furthermore, it is possible that when the rotor speed increases in the second control, the control unit determines the torque reduction amount in the first control and the torque increase amount in the second control in such a manner that the increased rotor speed is below the rated rotor speed in the rated output mode.

[0031] A wind turbine generator according to one aspect of the present disclosure includes a wind turbine, a generator that generates electricity by rotation of a rotor of the wind turbine, and the control unit according to any one of the above aspects.

[0032] A control method of one scheme of the present disclosure is a control method for a wind power generation device for controlling the power generation output of the wind power generation device, the wind power generation device comprising a windmill and a generator for generating power by rotating a rotor of the windmill, the control method comprising a rated output mode for controlling the power generation output of the generator so as to achieve a rated value, a temporary power generation output increase process is performed when the rotor speed in the rated output mode is in a state of a predetermined rotor speed decrease, in the temporary power generation output increase process, the torque applied to the generator is reduced to suppress the decrease in the rotor speed, and then the torque applied to the generator is increased in a state where the decrease in the rotor speed is suppressed to temporarily increase the power generation output.

[0033] A control program of one scheme of the present disclosure is executed by a control unit described in any one of the above-mentioned forms for controlling the power generation output of a wind power generation device, wherein the wind power generation device comprises a windmill, a generator for generating electricity by rotating a rotor of the windmill, and the control unit, and the control program causes the control unit to execute any one of the controls described in the above-mentioned forms or a temporary power generation output increase process.

[0034] Furthermore, a storage medium according to an aspect of the present disclosure is a computer-readable storage medium storing the control program.

[0035] Effects of the Invention

[0036] According to the present disclosure, the following effects are achieved.

[0037] (1) By applying the present disclosure, the amount of power generated in a constant period can be increased.

[0038] (2) In the present disclosure, a method can be formed to increase the amount of power generated by temporarily reducing the torque applied to the generator without increasing the target rotor speed or the actual rotor speed, and it is impossible to cause an increase in the windmill load caused by increasing the target rotor speed or the actual rotor speed, or to cause the windmill to stop easily due to falling into an over-rotation state.

[0039] (3) By applying the present disclosure, it is possible to suppress a decrease in electric power when the power generation output decreases, and as a result, it is possible to improve the power quality of the wind turbine generator system by alleviating fluctuations in the generated electric power during the period. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a diagram schematically showing a wind turbine generator according to one embodiment of the present disclosure.

[0041] Figure 2 This is a diagram showing functional blocks of a control unit that controls a wind turbine generator.

[0042] Figure 3 This is a graph showing the relationship between torque and the rotor speed of a wind turbine.

[0043] Figure 4A This is a diagram for explaining the set torque when the target power generation output is reduced, using a coordinate diagram showing the relationship between the torque and the rotor speed of the wind turbine.

[0044] Figure 4B This is a diagram for explaining the set torque when the target power generation output is reduced, using a coordinate diagram showing the relationship between the torque and the rotor speed of the wind turbine.

[0045] Figure 5 This is a flowchart showing a control method according to an example of the present embodiment.

[0046] Figure 6 It is a coordinate graph showing the time changes of the hub height wind speed, the rotor speed of the wind turbine, the pitch angle, the power generation output, and the torque, which is a simulation result.

[0047] Figure 7 It is a graph showing other simulation results, showing the time changes of the hub height wind speed, the rotor speed of the wind turbine, the pitch angle, the power generation output, and the torque.

[0048] Figure 8 is a table showing the conditions of the simulation. DETAILED DESCRIPTION

[0049] Hereinafter, one embodiment of the present disclosure will be described.

[0050] As one embodiment of the present disclosure, a wind power generation device 1 is Figure 1 As shown, the nacelle 3 is rotatably mounted on the tower 2 through a vertical axis perpendicular to the ground, and the hub 4 is mounted on the nacelle 3. Blades 5 are mounted on the hub 4. The rotor composed of the hub 4 and the blades 5 is rotatable through a horizontal axis. The rotor is connected to a generator 6 installed in the nacelle 3 through a speed increaser, etc., not shown.

[0051] Furthermore, the wind turbine generator 1 has a control unit 10 for controlling the power generation output of the wind turbine generator 1. An anemometer (not shown) for measuring the wind speed of the hub 4 is provided above the nacelle 3. The measurement result of the anemometer is sent to the control unit 10. The installation position of the anemometer is not particularly limited. Furthermore, the wind turbine generator 1 may not have an anemometer, and may obtain wind speed information based on external measurement data or the like.

[0052] Furthermore, the control unit 10 may be arranged outside the nacelle 3, inside the nacelle 3 or inside the tower 2, and may be connected to the equipment inside the nacelle 3 via a network. The control unit 10 is equivalent to the control unit of the wind turbine generator of the present disclosure. In the present embodiment, the wind turbine generator 1 is a horizontal axis wind turbine generator, but the wind turbine generator of the present disclosure is not limited to a horizontal axis device.

[0053] like Figure 2 As shown, the control unit 10 includes a CPU 11 and a storage unit 12. The storage unit 12 uses a computer-readable storage medium such as a ROM, RAM, non-volatile memory, HDD, SSD, etc., and stores a control program for controlling the wind turbine generator 1, an operating parameter of the wind turbine generator 1, various setting data, etc. The control program of this embodiment is stored in the storage unit 12, but the control program of the present disclosure may also be stored in a removable storage unit such as a USB memory.

[0054] The CPU 11 reads out a control program for wind power generation from the storage unit 12 or the like. The read-out program is expanded on the RAM or the like, and is executed by the cooperation of the CPU 11 and the RAM or the like.

[0055] The storage unit 12 stores parameters such as pitch control, torque control, torque-windmill rotor speed adjustment curve in the rated operation mode, a reference for the rotor speed reduction state for transition to the first control in the temporary power generation output increase process, a torque reduction amount in the first control, a predetermined first control time, a torque increase amount in the second control, a second control time, a target power generation output reduction amount in the temporary power generation output increase process, and a standby time after the target power generation output reduction. These data may also be changeable by the operator.

[0056] The control unit 10 can control the entire wind turbine generator 1 , and can perform pitch control for changing the installation angle of the blades 5 , yaw control of the nacelle 3 , torque control of the generator 6 , and the like as power generation output control in the generator 6 .

[0057] The wind turbine generator 1 is normally operated in a rated output mode. The rated output mode is a mode in which control is performed so that the power generation output of the generator 6 becomes a rated value. Control of the rated output mode in the wind turbine generator 1 will be described.

[0058] When the rated output mode starts, the control unit 10 obtains the current rotor speed of the wind turbine and controls the rated output (rotor speed) mainly based on the current rotor speed. In the power generation output control, the power generation output of the wind turbine generator 1 is controlled to reach the rated output value as the target through pitch control to change the installation angle of the blades 5, yaw control to adjust the orientation of the nacelle 3, and torque control of the generator 6. In the case where the power generation output of the wind turbine generator 1 cannot maintain the rated output, it can be controlled according to Figure 3 The power generation output is controlled by adjusting the torque-rotor speed curve shown.

[0059] Next, the temporary power generation output increase process in this embodiment will be described.

[0060] When the wind turbine generator 1 is operated at a wind speed near the rated wind speed (but above the rated wind speed), the rotor speed is operated at an operating point corresponding to the rated rotor speed, and the load torque is operated at an operating point corresponding to the rated torque. When the wind speed decreases with the passage of time from this operating state, the aerodynamic torque obtained by the wind decreases, so the load torque is increased according to the load torque. Figure 3 The torque curve of the load torque is continuously decreasing. At this time, the load torque is greatly reduced relative to the rotor speed, so the power output is greatly reduced.

[0061] According to the "Reason why the wind speed drop is temporary" mentioned later, in most cases the wind speed drop is temporary, but Figure 3 When the wind turbine generator 1 is controlled according to the torque curve shown in FIG. 1 , the power output changes drastically with the increase or decrease of the wind speed. In the operation state near the rated wind speed, the maximum power output is controlled so as to avoid exceeding the rated output when the wind speed increases, so the maximum power output is generally adjusted to the rated output. However, when the wind speed decreases, the power output becomes the power output according to the wind speed, so the higher the turbulence intensity at the location where the wind turbine is installed, the lower the power generation within the operation range (the sum of the power output obtained during the constant period).

[0062] Therefore, in this embodiment, when the rotor speed decreases (slightly) compared to the rated rotor speed due to a decrease in wind speed, the target power generation output of the wind mill is instantly reduced by utilizing the target power generation output reduction function of a general wind mill, and the power generation can be increased according to the <estimation principle> described later.

[0063] Furthermore, in the present embodiment, a reference related to the decreasing state of the rotor rotation speed is determined in advance, and control can be performed according to the reference.

[0064] In addition, in a general large-scale variable speed wind turbine with a variable pitch system, there is a function of being able to change the target power generation output. This function is usually achieved by reducing the target rotor speed and the set torque. In most cases, the target rotor speed and the set torque can be changed not only by the wind turbine control maker (manufacturer) but also by the owner. In this embodiment, there is the following feature: since this function can be used during operation, the control of the target power generation output can be easily implemented by people other than the manufacturer. It also has the feature that the control of the target power generation output can be applied without changing the existing control system.

[0065] It should be noted that the power generation output will decrease once during the control process of decreasing the target power generation output, which is a case where the existing function of decreasing the target power generation output is utilized. It is important not to increase the target rotor speed more than the rated rotor speed but to increase the actual rotor speed temporarily (within the range not exceeding the rated rotor speed), so a function of increasing the rotor speed by temporarily decreasing the load torque while maintaining the target power generation output at the rated output may also be provided.

[0066] Next, the function of reducing the target power generation output will be described.

[0067] Regarding the function of reducing the target power generation output, use Figure 4A and Figure 4BThe function of reducing the target power output is a function commonly used in general pitch control and control of variable speed large wind turbines. Usually, the target power output is set to the rated output. The target power output can be arbitrarily changed in the direction of reduction according to system requirements, operation control, and operation status. When reducing the target power output, control (action) is performed in the direction of reducing the rotor speed and torque at the same time ( Figure 4A , Figure 4B ).

[0068] Therefore, when the wind turbine is instructed (controlled) to reduce the target power output while operating at the rated output, the wind turbine is controlled to reduce the set torque in order to reduce the current power output to match the target power output while reducing the rotor speed through pitch control. At this time, pitch control requires more time than torque control before the control effect is obtained, so the rotor speed will temporarily increase slightly. However, this action (control) is implemented when the rotor speed is lower than the rated rotor speed, so the increase in rotor speed caused by this action is controlled to a degree not exceeding the rated rotor speed. Here, during this control action, the target rotor speed is always below the rated rotor speed, so when the rotor speed exceeds the target value, the rotor speed is immediately controlled to be below the target value.

[0069] It should be noted that Figure 3 , Figure 4A and Figure 4B The coordinate graph shown in FIG. 1 is an example, and the relationship between the rotor speed and the torque in the present disclosure is not limited to the relationship shown in the graph.

[0070] <Estimate principle>

[0071] When the wind speed is decreasing, the rotor loses kinetic energy when the rotor speed decreases. Therefore, when the wind speed increases next, the aerodynamic torque obtained is used for both rotor acceleration and power generation. On the other hand, when the wind speed decreases slightly, the kinetic energy of the rotor can be maintained high by keeping the rotor speed high in advance. Therefore, it is estimated that power generation energy can be obtained immediately when the wind speed increases next. When the wind speed changes drastically, the state of wind speed increasing immediately after the wind speed decreases frequently occurs.

[0072] <The drop in wind speed is a temporary reason>

[0073] Generally, the wind speed at a specific location is determined by the air pressure configuration, temperature, etc., so the wind speed can be considered to be roughly constant within the time period that is considered to be the same (about 10 minutes to 1 hour). On the other hand, when the wind turbine generator 1 is installed in a place with complex terrain shape such as a mountainous area, the wind disorder (turbulence) caused by the terrain shape becomes higher. Therefore, in the wind turbine generator 1 installed in a place with complex terrain shape, it is known that compared with the case where it is installed in a flat terrain, even if the average wind speed (average wind speed) for a constant time is the same, the change in wind speed (turbulence intensity) becomes larger. This wind speed change is caused by the peeling flow of the terrain (mountains) located upstream, and the large-scale peeling vortex generated by the peeling and the fine vortex generated by the terrain shear are mixed and continuously flow into the target location, causing changes (changing at intervals of several seconds). This wind speed change repeatedly decreases and increases, so the wind speed drops in most cases and recovers from the drop in wind speed within a period of several seconds to tens of seconds.

[0074] Below, through Figure 5 The control method of the temporary power generation output increase process in this embodiment is described with reference to the flowchart of FIG. It should be noted that the following control method can be executed by a program that operates in the control unit 10.

[0075] When the control of the wind turbine generator 1 is started, the pitch angle is obtained in order to determine whether the wind turbine is operating near the rated wind speed. When the obtained pitch angle value is below the threshold, the control unit 10 determines that the obtained pitch angle is within the control object range (step s1). The threshold value of the effective pitch angle range is, for example, below the maximum opening angle + 3 degrees. The threshold value is pre-set, stored in the storage unit 12, etc., and read from the storage unit 12, etc. as needed.

[0076] If the acquired pitch angle value is not less than the threshold value (No in step s1), the process waits. That is, the determination of whether the pitch angle value is less than the threshold value is repeated (step s1).

[0077] If the acquired pitch angle value is less than the threshold value (Yes in step s1), the control unit 10 determines that the rotor speed is in a tendency to decrease (step s2). The judgment condition of whether the rotor speed is in a state of decreasing is preset, stored in the storage unit 12, etc., and read from the storage unit 12, etc. as needed. Regarding the state of decreasing rotor speed, for example, when the state of decreasing rotor speed continues for a predetermined time, it can be determined that the rotor speed is in a state of decreasing.

[0078] Regarding the judgment of whether the rotor speed is reduced, the pitch angle is used for judgment in the above embodiment, but it is not limited to this scheme, and it can also be judged by the measurement result of the measured wind speed. In this embodiment, the judgment of whether the rotor speed is reduced can be judged by the reduction amount relative to the rated rotor speed, the reduction ratio, the state of the rated output reduction continuing for a predetermined time, etc., but the present disclosure is not limited to specific conditions.

[0079] In the process of temporarily increasing the power generation output, the 1-second average value and the instantaneous value of the rotor speed are used. When the 1-second average rotor speed is above a predetermined speed (for example, above 18.7 rpm) and the instantaneous rotor speed is lower than a predetermined rotor speed (for example, 18.7 rpm), it is judged that the rotor speed is in a tendency to decrease (yes in step s2). Then, the setting is performed in a manner that causes the power generation output to decrease to a predetermined amount (step s3). In step s3, for example, the setting is performed in a manner that causes the power generation output to decrease to a target power generation output (for example, 1800 kW) that is decreased from the rated output (for example, 2000 kW). Next, the control of the power generation output limit is maintained. That is, the state of decreasing the target power generation output is maintained (step s4). Next, it is determined whether the decrease in the target power generation output has been maintained for a predetermined time (in this example, 1 second) (step s5). The predetermined time in step s5 is pre-set, stored in the storage unit 12, etc., and read out from the storage unit 12, etc. as needed.

[0080] If the suppression time of the target power generation output does not reach the specified time (specified value) (No in step s5), the control unit 10 maintains the restriction of the target power generation output (step s4), and repeats the judgment of whether the time of suppressing the target power generation output is more than the specified time (specified value) (step s5). The restriction of the target power generation output is equivalent to the first control of the present disclosure.

[0081] When the suppression time of the target power generation output is greater than the prescribed time (prescribed value) (yes in step s5), the control unit 10 releases the restriction on the target power generation output (step s6). Moreover, in order to avoid continuously controlling the target power generation output, the monitoring state of the target power generation output is returned again after a constant prescribed time (10 seconds in this example) (step s6). The process of returning to the monitoring state after the restriction of the target power generation output is equivalent to the second control of the present disclosure. That is, the second control is a control that temporarily increases the power generation output by increasing the torque while suppressing the decrease in the rotor speed, and can be performed by restoring the torque in a manner that returns to the rated state. However, in the second control, the torque can also be increased to a torque different from the rated torque. It should be noted that after the temporary power generation output increase process is executed and after a predetermined standby time, the control to return to normal control is performed, and the "control to return to normal control" refers to the operation of returning to the original control of the wind turbine generator.

[0082] It should be noted that in this embodiment, the rotor speed of the wind turbine is reduced by controlling the reduction of the target power generation output together with the reduction of the torque through pitch control. However, when the target power generation output is reduced, the pitch control may not be performed, or the adjustment amount of the pitch control may be reduced, or the pitch control may be different from the normal pitch control, or it may be possible to pre-set whether to perform a pitch control different from the normal pitch control. Here, the normal pitch control is the pitch control at the rated output.

[0083] Among them, by performing pitch control while the target power generation output is reduced, the pitch is controlled in advance to the feathering direction (direction that reduces the power generation output) when the wind speed decreases, so when the wind speed rises suddenly afterwards, the rotor speed is unlikely to increase suddenly. Therefore, the risk of the wind turbine stopping due to over-rotation can be reduced.

[0084] Figure 6 Result of verifying the effect of the present disclosure through simulation is shown in FIG.

[0085] Simulation in Figure 8 The analysis was performed under the conditions shown in the figure. Bladed Ver4.7 (trademark) was used as the analysis software.

[0086] exist Figure 6 In the simulation shown, the behavior of the windmill relative to the same inflow wind (three-dimensional turbulent wind) is analyzed, and the difference in behavior between the conventional control and the control state of the present embodiment is shown. In the behavior of about 20 seconds, the control operation of the present embodiment detects the decrease in the rotor speed and performs control to reduce the target power output, so the power output decreases and the rotor speed increases slightly. It can be confirmed that the power output increases thereafter by this control of the present embodiment.

[0087] Figure 7 is a diagram showing other simulation results. Figure 6 Same, in Figure 7 In the example above, it can be confirmed that the target power generation output is decreasing (operating) at about 10 seconds. Figure 7 In the example shown, the maximum rotor speed is reached at about 17 seconds, but the maximum rotor speed is lowered in the control operation of this embodiment compared to the conventional control. Figure 7 In the control of this embodiment, it can be seen that there is not only an effect of increasing the amount of power generated, but also an effect of suppressing the rotor speed relative to the gusts that will be generated later. As a result, the fluctuation of power in the wind turbine generator 1 is alleviated, and the risk of the wind turbine stopping due to over-rotation can be reduced.

[0088] As mentioned above, the present disclosure has been described based on the above-mentioned embodiment, but the scope of the present disclosure is not limited to the contents of the above-mentioned description. The above-mentioned embodiment can be appropriately modified as long as it does not depart from the scope of the present disclosure.

[0089] This application is based on Japanese patent application (Japanese Patent Application No. 2020-035737) filed on March 3, 2020, the contents of which are incorporated herein by reference.

Claims

1. A control unit for controlling a power generation output of a wind power generation device, the wind power generation device comprising a windmill and a generator for generating power by rotating a rotor of the windmill, The control unit has a rated output mode for controlling the generator so that the power generation output of the generator reaches a rated value. The control unit is configured to perform a temporary power generation output increase process. The temporary power generation output increase processing includes: when the rotor speed of the windmill in the rated output mode becomes a rotor speed decrease state that is lower than the rated rotor speed due to a decrease in wind speed, and the rated output decrease state continues for a predetermined time, a first control is performed to reduce the target power generation output compared with the rated output mode and maintain the target power generation output decrease state for a predetermined time to reduce the torque applied to the generator to suppress the decrease in the rotor speed; and then a second control is performed to release the restriction on the target power generation output and increase the torque while the decrease in the rotor speed is suppressed to temporarily increase the power generation output.

2. The control unit according to claim 1, wherein: The control unit is configured to perform pitch control for changing an attachment angle of blades of the wind turbine.

3. The control unit according to claim 2, wherein: The control unit can set the pitch control to a control different from the normal pitch control during the execution of the temporary power generation output increase process.

4. The control unit according to claim 1, wherein: The state of the rotor speed reduction is determined by the value of the pitch angle.

5. The control unit according to claim 1, wherein: The control unit performs control to return to normal control after executing the temporary power generation output increase process and after a predetermined standby time.

6. The control unit according to claim 1, wherein: The decrease in the rotor speed is suppressed by at least any one of a decrease in the rotor speed, maintenance of the rotor speed, or an increase in the rotor speed.

7. The control unit according to claim 1, wherein: The control unit determines a reduction amount of the torque in the first control and an increase amount of the torque in the second control so that the increased rotor speed is equal to or less than a rated rotor speed in the rated output mode when the rotor speed increases in the second control. 8 . A wind power generator comprising a wind turbine, a generator for generating electric power by rotation of a rotor of the wind turbine, and the control unit according to claim 1 .

9. A control method for controlling a power generation output of a wind power generation device, the wind power generation device comprising a wind turbine and a generator for generating power by rotating a rotor of the wind turbine, The control method includes a rated output mode for controlling the generator so that the power generation output of the generator reaches a rated value. When the rotor speed of the windmill in the rated output mode becomes lower than the rated rotor speed as the wind speed decreases, and the rated output decreases for a predetermined time, the target power generation output is reduced compared to the rated output mode and the target power generation output decrease is maintained for a predetermined time to reduce the torque applied to the generator to suppress the decrease in the rotor speed, and then the restriction on the target power generation output is released and the torque applied to the generator is increased while the decrease in the rotor speed is suppressed to temporarily increase the power generation output.

10. A computer-readable storage medium storing a control program executed by a control unit for controlling a power generation output of a wind power generation device, the wind power generation device comprising a windmill, a generator for generating power by rotating a rotor of the windmill, and the control unit, When the control program is executed by the control unit, the wind turbine generator performs the following processing: when the rotor speed of the windmill in the rated output mode that is controlled so that the power generation output of the generator becomes a rated value becomes a rotor speed lower than the rated rotor speed due to a decrease in wind speed, and the state of rated output decrease continues for a predetermined time, the target power generation output is reduced compared with the rated output mode and the state of target power generation output decrease is maintained for a predetermined time to reduce the torque applied to the generator to suppress the decrease in the rotor speed, and then the restriction on the target power generation output is released and the torque is increased while the decrease in the rotor speed is suppressed to temporarily increase the power generation output.

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