JP2020067023A - Wind power generation system - Google Patents

Abstract

To provide a wind power generation system including an operation control unit, which can improve blade aerodynamic performance in consideration of a blade deformation amount, and suppress deterioration in power generation efficiency in consideration of actual machine operation.SOLUTION: A wind power generation system comprises a plurality of blades whose pitch angle can be changed by a pitch angle drive device, a rotor that receives wind at the blades and rotates, and a power generator that uses the rotational energy of a rotor to generate power. The wind power generation system comprises a pitch angle command value calculation unit that obtains a pitch angle command value in consideration of a deformation amount of the blade, and is configured to change a pitch angle by giving the pitch angle command value of the pitch angle command value calculation unit to the pitch angle drive device.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a wind power generation system, and more particularly to a wind power generation system that reduces a decrease in power generation efficiency due to an increase in blade deformation amount.

  In recent years, global warming due to an increase in carbon dioxide emissions and energy shortage due to depletion of fossil fuels have been regarded as problems. Therefore, as a power generation system that reduces carbon dioxide emissions and does not use fossil fuels, the introduction of a power generation system that uses renewable energy obtained from nature such as wind power and sunlight has attracted attention.

  Among the power generation systems using renewable energy, a solar power generation system is generally used, but the output directly changes due to solar radiation, so the output changes greatly and it is not possible to generate power at night. On the other hand, the wind power generation system is capable of relatively stable power generation day and night by selecting and installing in a place where the wind conditions such as wind speed and direction are stable.

  A general large-scale wind power generation system is equipped with a pitch drive device for adjusting the pitch angle and a power converter for adjusting the generator torque, and by adjusting the pitch angle and the generator torque, any The control is implemented to maximize the generated power in the wind speed range.

  As one of the above control methods, there is, for example, Patent Document 1. In Patent Document 1, at least a measurement information input processing step of inputting measurement information of a wind speed and a wind direction of a wind flowing into a wind turbine blade, and in advance for calculating the input measurement information and torque in the measurement information input processing step. Based on the stored data, calculate the generated torque that is actually generated in each blade element and the optimum torque that is assumed in each blade element and is calculated by the product of the radial position, weight and angular velocity of each blade element. A torque calculation processing step, a torque comparison processing step of comparing the generated torque calculated in the torque calculation processing step with the optimum torque, and a generated torque and the optimum torque based on the result of the comparison in the torque comparison processing step. In order to reduce the difference, each of them is individually selected according to the features of the airflow generator, pitch angle drive mechanism, and yaw angle drive mechanism. It is possible to control. A technique for improving the power generation efficiency of the wind power generation system by this is disclosed.

Patent No. 5323133

  2. Description of the Related Art In recent years, wind power generation systems have been required to improve their generated power by increasing their size, and along with this, the blades have become longer. Particularly in a downwind wind turbine, the blade is attached to the leeward side, and the blade bends to the leeward side due to the wind load, so there is less risk of collision with the tower. Therefore, it is possible to make the upwind wind turbine long blades (hereinafter referred to as long blades) by making the blades flexible.

  By applying the technique disclosed in Patent Document 1, it is possible to operate at a pitch angle in consideration of blade aerodynamic performance according to the wind speed, the rotation speed of the rotor or the generator, and improve the power generation efficiency.

  However, with a long blade blade capable of improving power generation efficiency, the amount of deformation of the blade may increase. The blade aerodynamic performance is determined by the wind speed, the rotation speed, and the inflow relative wind speed determined by the blade deformation amount and the pitch angle of the blade root. In the case of a rigid structure blade, since there is no blade deformation amount, once the wind speed and rotation speed are determined, the pitch angle that maximizes aerodynamic performance is uniquely determined. However, in the case of a flexible structure blade, it is necessary to derive the pitch angle that maximizes aerodynamic performance by considering the effect of blade deformation (deflection and twist) on the relative inflow wind speed. Therefore, even if the inflow relative wind speed is the same, the rigid structure blade and the flexible structure blade have different pitch angles that maximize aerodynamic performance.

  Therefore, when Patent Document 1 is applied to the long blade, it is not possible to consider that the pitch angle that maximizes aerodynamic performance is changed depending on the blade deformation amount, as compared to the case where the blade is applied to a rigid structure blade having a small blade deformation amount. Therefore, the pitch angle may be adjusted to reduce the power generation efficiency. In addition, since the azimuth angle is not used as the input value, the effect of wind shear that the wind speed becomes higher as the altitude becomes higher cannot be considered. Furthermore, in the downwind wind turbine, it is not possible to consider the effect of the tower shadow that the wind speed decreases near the tower due to the influence of the tower.

  Therefore, the influence of the change in wind speed during one rotation cycle cannot be taken into consideration, which may cause a decrease in power generation efficiency and an increase in blade vibration. Further, if the error between the numerical analysis data of the analysis model of the wind power generation system and the characteristics of the actual machine is large, the power generation efficiency may be further reduced.

  From the above, the object of the present invention is to improve the blade aerodynamic performance by considering the blade deformation amount, and to provide a wind power generation system provided with an operation control unit that suppresses a decrease in power generation efficiency by considering the actual machine operation. That is.

  In order to solve the above-mentioned problems, the present invention provides, "a plurality of blades whose pitch angle can be changed by a pitch angle drive device, a rotor which receives wind from the blades to rotate, and a power generation which generates electric power using rotational energy of the rotor. A wind power generation system including a machine, comprising a deformation amount consideration pitch angle command value calculation unit for obtaining a pitch angle command value considering the deformation amount of a blade, and changing the pitch angle command value of the deformation amount consideration pitch angle command value calculation unit. A wind power generation system characterized by changing the pitch angle given to the pitch angle driving device ".

  According to the present invention, a pitch angle command value in consideration of the amount of blade deformation, further, by correcting the pitch angle command value based on the actual machine operation data, a control device capable of improving the power generation efficiency or reducing the load. A provided wind power generation system can be provided.

The figure which shows the schematic structural example of the whole general wind power generation system to which this invention can be applied. The block diagram which shows the processing outline of the operation control part mounted in the controller 11 of the wind power generation system 1. FIG. 3 is a block diagram showing an outline of a pitch angle control unit 22 in the variable speed control unit 21. Schematic which shows the relationship of the wind speed of the wind power generation system 1, generated electric power, rotation speed, generator torque, and a pitch angle. 3 is a block diagram of a deformation amount consideration pitch angle command value calculation unit 100 according to the first embodiment of the present invention. FIG. FIG. 3 is a block diagram showing the relationship between the analysis model 101 and its input according to the first embodiment of the present invention. The figure which shows the flow for creating the analysis model 101 which concerns on Example 1 of this invention beforehand. The block diagram which shows the relationship of the learning device 102 of the deformation amount consideration pitch angle command value calculation part 100 which concerns on Example 1 of this invention, and its input. 3 is a block diagram showing an outline of processing of an operation control unit mounted in the controller 11 according to the first embodiment of the present invention in a wider wind speed range. FIG. The flowchart for creating beforehand the analytical model 101 of the generator torque corresponding to a deformation consideration pitch angle. The figure for demonstrating the angle of attack with respect to the relative wind speed which flows into the blade element of a certain blade cross section in the wind power generation system 1, and the relationship of a pitch angle and an initial twist angle. The figure for demonstrating the relationship of the attack angle with respect to the relative wind speed which flows into the blade element of a certain blade cross section in the wind power generation system 1, a pitch angle, an initial helix angle, and blade deformation. The figure for demonstrating degradation of aerodynamic performance in a certain blade section by blade deformation in wind power generation system 1. The figure for demonstrating the relationship between the wind speed and the force added to a rotation direction when the operation control part which concerns on Example 1 of this invention is applied, and when not applied. The block diagram which shows the operation control part of the wind power generation system which concerns on Example 2 of this invention. The block diagram which shows the operation control part of the wind power generation system which concerns on Example 3 of this invention. The block diagram which shows the operation control part of the wind power generation system which concerns on Example 4 of this invention. The block diagram which shows the operation control part of the wind power generation system which concerns on Example 5 of this invention. The block diagram which shows the operation control part of the wind power generation system which concerns on Example 6 of this invention. The flowchart which shows a series of processes relevant to the learning device 102.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing, the same components are designated by the same reference numerals, and detailed description of overlapping portions will be omitted.

  In describing the first embodiment, first, the configuration and control method of a conventional general wind power generation plant will be described with reference to FIGS. 1 to 4, and then the first embodiment will be described with reference to FIGS. 5 to 14. I will explain.

  FIG. 1 shows a schematic configuration example of a general wind power generation system to which the present invention can be applied.

  The wind power generation system 1 of FIG. 1 includes a rotor 4 including a plurality of blades 2 and a hub 3 that connects the plurality of blades 2. The rotor 4 is connected to the nacelle 5 via a rotary shaft (not shown in FIG. 1), and the position of the blade 2 can be changed by rotating the rotor 4. The nacelle 5 rotatably supports the rotor 4. When the blade 2 receives wind, the rotor 4 rotates, and the rotational force of the rotor 4 rotates the generator 6 in the nacelle 5 to generate electric power. A wind direction wind speed sensor 7 for measuring the wind direction and the wind speed is provided on the nacelle 5.

  Each blade 2 is provided with a pitch angle drive device 8 capable of adjusting the angle (pitch angle) of the blade 2 with respect to the wind. By using the pitch angle drive device 8, the wind energy (air volume) received by the blade 2 can be adjusted by changing the pitch angle to change the rotational energy of the rotor 4 with respect to the wind. This makes it possible to control the rotation speed and the generated power in a wide wind speed range.

  In the wind power generation system 1, the nacelle 5 is installed on the tower 9 and has a mechanism (not shown) rotatable with respect to the tower 9. The tower 9 supports the load of the blade 2 via the hub 2 and the nacelle 5, and is fixed to a base (not shown) installed at a predetermined position on the ground, offshore, or in a floating body.

  The power generator 10 installed in the tower 9 controls the torque generated by the power generator (hereinafter, referred to as “generator torque”), so that the power generator 6 can control the rotation torque of the rotor 4.

  Further, the wind power generation system 1 includes a controller 11, and the controller 11 generates a generator based on the rotation speed output from the rotation speed sensor 12 that measures the rotation speed of the generator 6 and the generator torque of the generator 6. By adjusting 6 and the pitch angle driving device 8, the generated power and the rotation speed of the wind power generation system 1 are adjusted.

  The controller 11 is, for example, a control panel or a SCADA (Supervisory Control And Data Acquisition). Further, the controller 11 is realized by a processor such as a CPU (Central Processing Unit) (not shown), a ROM that stores various programs, a RAM that temporarily stores the data of the calculation process, and a storage device such as an external storage device. At the same time, a processor such as a CPU reads and executes various programs stored in the ROM, and stores the operation result, which is the execution result, in the RAM or the external storage device.

  The blade 2 may have a rotor diameter of 100 m or more, for example. Further, when the rotor diameter is 180 m or more, the effect of the control corresponding to the flexible structure is particularly large. Further, in the blade 2, each blade element has a shape initial twist from the surface of rotation, but the web and spar cap of the blade 2 are twisted so that a twist of 0.2 ° or more occurs from the force applied by wind during power generation operation. Etc. can be designed. Further, in the case of the flexible structure blade which is twisted by 0.5 ° or more during the power generation operation, the control of the present embodiment provides a particularly remarkable effect.

  FIG. 2 shows a block diagram of the operation control unit mounted on the controller 11. The variable speed control unit 21, which is the operation control unit shown in FIG. 2, controls the pitch angle by feedback control based on the deviation between the target value and the measured value of the generator torque and the deviation between the target value and the measured value of the generator rotation speed. A pitch angle control unit 22 that determines a value is provided. The variable speed control unit 21 also includes a generator torque control unit 23 that determines a generator torque command value by feedback control based on the deviation between the target value of the generator rotation speed and the measured value. The pitch angle command value is given to the pitch angle drive device 8 of FIG. 1 installed for each blade 2 to adjust each pitch angle, and the generator torque command value is set to the generator 6 of FIG. Then, the electric power converter 10 is also included) to adjust the generator torque.

  FIG. 3 is a block diagram showing an outline of the pitch angle control unit 22 in the variable speed control unit 21. The pitch angle control unit 22 includes a rotation speed control unit 22a and a torque control unit 22b. The rotation speed control unit 22a determines the pitch angle command value by feedback control based on the deviation between the target value of the generator rotation speed and the measured value. Further, the torque control unit 22b determines the pitch angle command value by feedback control based on the deviation between the target value of the generator torque and the measured value. By adding these two values, the final pitch angle command value of the pitch angle control unit 22 is determined.

  FIG. 4 shows characteristics of the wind power generation system 1 obtained by the operation control unit mounted on the controller 11 shown in FIGS. 2 and 3.

  FIG. 4 shows the relationship between the generated power, the rotation speed of the generator, the generator torque, and the pitch angle with respect to the wind speed. The horizontal axis of each graph shows the wind speed, and the wind speed increases toward the right side. In addition, the vertical axis of each graph indicates that the generated power, the rotation speed, and the generator torque increase as they go upward. Regarding the pitch angle, the upper side indicates the feather side (to release the wind) and the lower side indicates the fine side (to receive the wind).

  Power generation is performed within a range from a cut-in wind speed Vin at which rotation of the rotor 4 starts to a cut-out wind speed Vout at which rotation of the rotor 4 is stopped. Up to the wind speed Vd, the generated power value increases as the wind speed increases. The generated power is controlled to be constant at wind speed.

  The controller 11 controls the generator torque so that the rotation speed is constant (Wlow) from the cut-in wind speed Vin to the wind speed Va, and generates power from the wind speed Va to the wind speed Vb such that the rotation speed is proportional to the wind speed, for example. Control machine torque. The steps up to this point are controlled and executed by giving a generator torque command value by the generator torque control unit 23 in FIG.

  When the wind speed reaches the wind speed Vb and the rotation speed reaches the rated rotation speed Wrat, the generator torque and the pitch angle are controlled so as to maintain the rated rotation speed Wrat in the wind speed state equal to or higher than the wind speed Vb. At this stage, the pitch angle control unit 22 and the generator torque control unit 23 shown in FIG. 2 are operating cooperatively. For example, as a result of the operation of the pitch angle control unit 22, the pitch angle command value changes, the rotation speed of the rotor 4, and thus the generator rotation speed fluctuates, and the generator torque control unit 23 generates power to keep the rotation speed constant. By executing the process of changing the machine torque command value, the generator torque and the pitch angle are controlled so as to maintain the rated rotation speed Wrat.

  In the control by the controller 11, basically, the generator torque control is performed to secure the generated power. In controlling the generator torque, the generator torque is changed in the range from the wind speed Vb to the wind speed Vd until it reaches the rated generator torque Qrat according to the wind speed, and in the range from the wind speed Vd to the cutout wind speed Vout, the rated generator is set. Hold the torque Qrat.

  In the control of the pitch angle, the pitch angle is maintained at the fine angle θmin up to the wind speed Vc, and the pitch angle is changed from the fine side θmin to the feather side θmax in the range from the wind speed Vc to the cutout wind speed Vout according to the wind speed. However, in the example of FIG. 4, the control of the generator torque and the pitch angle is overlapped in the range from the wind speed Vc to the wind speed Vd, but this is set as Vc = Vd to eliminate the overlap and control the generator torque. You may make it control a pitch angle independently.

  The present invention is based on the wind power generation system described with reference to FIGS. 1 to 4 described above, and is intended to prevent a decrease in power generation efficiency or an increase in blade vibration due to deformation of the blade 2 by adjusting the pitch angle.

  In the first embodiment of the present invention, particularly in the wind speed region such as the cut-in wind speed Vin to the wind speed Vd where the improvement of the power generation efficiency is required, the decrease of the power generation efficiency due to the deformation of the blade or the increase of the blade vibration is adjusted by adjusting the pitch angle. To prevent.

  FIG. 5 shows a block diagram of the deformation amount consideration pitch angle command value calculation unit 100 according to the first embodiment of the present invention. As shown in FIG. 5, the deformation amount consideration pitch angle command value calculation unit 100 includes an analysis model 101 and a learning device 102. In addition, the wind speed measurement unit 103 measures the wind speed, the rotation speed measurement unit (rotation speed measurement unit) 104 of the rotor or the generator measures the rotation speed of the generator, and the yaw error measurement unit 105 measures the yaw error with respect to the wind direction. Then, the nacelle tilt angle measuring unit 106 measures the nacelle tilt angle, the azimuth angle measuring unit 107 measures the azimuth angle, the generated power measuring unit 108 measures the generated power, and the blade deformation amount measuring unit 109 measures the blade deformation amount. Is measured and these measured signals 110 are input to the deformation amount consideration pitch angle command value calculation unit 100.

  From the analysis model 101 given the measurement signal 110, the deformation amount consideration pitch angle command value calculated in advance by simulation is output. The learning device 102 learns a function that outputs a pitch angle command value during operation based on the measurement signal 110, and outputs a deformation amount consideration pitch angle command value by this function.

  In FIG. 5, a deformation amount consideration pitch angle command value calculation unit 100 according to the first embodiment of the present invention includes two calculation units (analysis model 101 and learning device 102) as a deformation amount consideration pitch angle command value calculation unit. However, these are in a relationship of correcting the characteristics of the initially prepared analysis model 101 according to the experience of the learning device 102 as shown in condition S10, or as shown in condition S11, the analysis model 101 in the initial state. By adding the output reflecting the experience of the learning device 102 to the output of the above, it is possible to obtain the optimum pitch angle command value in accordance with the current operating state.

  The pitch angle command value calculated by the deformation amount consideration pitch angle command value calculation unit 100 is obtained for each blade and directly given to the pitch angle drive device 8 of each blade, or the variable speed control unit 21 of FIG. It is added to the pitch angle command value given to each blade and given to the pitch angle driving device 8 in FIG.

  FIG. 6 is a block diagram showing the relationship between the analysis model 101 and its inputs. As shown in FIG. 6, the analysis model 101 includes, in the measurement signal 110, a wind speed measurement unit 103, a rotor or generator rotational speed measurement unit (rotational speed measurement unit) 104, a yaw error measurement unit 105, and a nacelle inclination angle. The measurement signals from the measuring unit 106 and the azimuth angle measuring unit 107 are input as a state signal 111, and a pitch angle command value (deformation amount consideration pitch angle command value) that considers the blade deformation amount stored in advance is output.

  FIG. 7 is a flowchart for creating in advance an analysis model that outputs a deformation amount-considering pitch angle command value. In process step S100, parameters such as wind speed, rotation speed, yaw error, nacelle inclination angle, and azimuth angle are input.

  In process step S101, the initial value of the pitch angle is input. In processing step S102, the deformation amount and aerodynamic performance of each blade element are calculated based on the input values of processing step S100 and processing step S101 by the aerodynamic and physical model of the blade.

  In processing step S103, it is determined whether or not a pitch angle that maximizes aerodynamic performance has been calculated. If not calculated, the value of the pitch angle is changed in processing step S101, and then the processing of processing step S102 is performed again. carry out. As a result, a pitch angle that maximizes aerodynamic performance considering the deformation amount is searched for for the same parameter.

  In processing step S104, it is determined whether or not possible measurement information is covered, and if not, the processing of processing steps S100 to S103 is executed again. As a result, the pitch angle that maximizes the aerodynamic performance in consideration of the deformation amount is searched for with respect to the parameters that cover the operating state of the wind turbine.

  In process step S105, an analysis model of a pitch angle that maximizes aerodynamic performance in consideration of a deformation amount is created for parameters that cover the operating state of the wind turbine.

  It should be noted that maximizing aerodynamic performance in a wind speed region from the cut-in wind speed Vin to the wind speed Vd, which requires improvement in power generation efficiency, maximizes torque or force applied in the rotation direction of the entire blade, and maximizes torque in the rotation direction of the entire blade. It indicates maximizing the quotient of the applied force and the force of the entire blade in the thrust direction, maximizing the lift of the entire blade, or maximizing the quotient of the lift and drag of the entire blade.

  In addition, the maximum aerodynamic performance during power generation operation such as wind speed Vd or more where a reduction in blade load is required, or during power generation standby during windstorm is to maximize the force applied in the rotational direction of the entire blade and the thrust direction of the entire blade. Shows that the quotient of applied force is maximized, the force applied in the thrust direction of the entire blade is minimized, the quotient of lift and drag of the entire blade is maximized, or the drag of the entire blade is minimized.

  Therefore, the deformation amount consideration pitch angle, which is referred to by the analysis model based on the measurement condition, can be changed according to the wind speed region.

  The realization form of the analysis model 101 may be a function form or a table reference type. The function is created by a fitting method such as interpolation and exterior or machine learning based on the data obtained by the analysis and the past operation. This makes it possible to reduce the information amount of the analysis model. However, there may be some approximation error. The table reference type can reduce approximation error by storing a large amount of data. However, the amount of information in the analysis model increases.

  When the analysis model 101 is configured as a table reference type, in the example of FIG. 6, a five-dimensional configuration in which five parameters of wind speed, rotation speed, yaw error, nacelle inclination angle and azimuth angle are used as input parameters and a pitch angle command value is output. Will be the table. The pitch angle command value is not limited to a constant value and may be a value having a predetermined width. The five-dimensional table format analysis model 101 is configured by executing the flow of FIG. 7 in advance, and outputs the pitch angle command value determined by the five input parameters input at the same time during actual operation. When there is no one value defined by the five parameters in the table, the process for obtaining the pitch angle command value is executed by appropriate interpolation processing or selecting an approximate value defined by many input parameters. be able to.

  As described above, in the analysis model 101 shown in FIGS. 6 and 7, the model characteristics of the analysis model 101 are set by the method of FIG. 7 and the measurement signal 110 according to the current state is input to the analysis model 101. Is used as the pitch angle command value in consideration of the deformation amount.

  FIG. 8 is a block diagram showing the relationship between the learning device 102 of the deformation amount consideration pitch angle command value calculation unit 100 and its input according to the first embodiment of the present invention.

  As shown in FIG. 8, the learning device 102 measures the wind speed by the wind speed measurement unit 103 and rotates the generator by the rotation speed measurement unit (rotation speed measurement unit) 104 of the rotor or the generator, as in the analysis model 101. The velocity is measured, the yaw error with respect to the wind direction is measured by the yaw error measuring unit 105, the nacelle tilt angle is measured by the nacelle tilt angle measuring unit 106, and the azimuth angle is measured by the azimuth angle measuring unit 107. It is input as the status signal 111.

  Further, in order to obtain the evaluation signal 112 in the evaluation signal determination unit 114, a measurement signal about the azimuth angle by the azimuth angle measurement unit 107, the generated power by the generated power measurement unit 108, and the blade deformation amount by the blade deformation amount measurement unit 109. To use.

  In the process of calculating the evaluation signal 112, the blade vibration velocity calculation unit 113 derives the blade vibration velocity from the measurement signal from the blade deformation amount measurement unit 109. The blade vibration velocity calculation unit 109 can derive the velocity by differentiating the measured strain or displacement, for example. Alternatively, the acceleration may be derived by twice differentiating the measured strain or displacement. Alternatively, it is possible to use the measured strain and displacement as they are.

  Due to the effects of wind shear and tower shadow, the blade vibration speed may increase depending on the azimuth angle. Further, in actual operation, the wind speed is accompanied by turbulence, so that the blade vibration speed may further increase due to the influence of the wind speed fluctuation. In particular, with a long blade, the blade vibration speed may be significantly increased.

  Therefore, the evaluation signal determination unit 114 shown in FIG. 8 has a function of determining whether to use the generated power and / or the blade vibration speed as the evaluation signal according to the magnitude of the azimuth angle and / or the blade vibration speed. For example, at the azimuth angle near the tower, the blade vibration speed can be used as the evaluation signal 112. Further, when the blade vibration speed is equal to or higher than an arbitrary threshold value, the blade vibration speed can be used as the evaluation signal 112, and when the blade vibration speed is equal to or lower than the threshold value, only the generated power may be used as the evaluation signal 112. As a result, in the learning device 102, the influence of the blade vibration speed can be considered, and in addition to the improvement of the generated power, the load of the blade can be optimized.

  Based on the state signal 111 and the evaluation signal 112, the learning device 102 learns a function that outputs a pitch angle command value that improves the evaluation signal 112 with respect to the state signal 111, by reinforcement learning (Reinforcement Learning). Reinforcement learning is, for example, using a state signal obtained from the environment such as a controlled object such as a wind power generation system, so that the expected value of the evaluation signal obtained from the present state to the future is maximized. This is a learning method for generating a signal. As the algorithm for reinforcement learning, known techniques such as Q-learning, deep reinforcement learning, and actor-critical can be used.

  When the analysis model 101 is in the form of a function, the function of the analysis model 101 and / or the function learned by the reinforcement learning by the learning device 102 may be updated. If the analysis model 101 is of the table reference type, the function learned by the reinforcement learning by the learning device 102 is updated, and the pitch angle command value output from the analysis model 101 is changed to the pitch angle command output from the learning device. The values are added as correction values, and the final pitch angle command value is calculated. As a result, even if the analysis model 101 is accompanied by a numerical error due to analysis, the learner 102 corrects the pitch angle command value based on the actual measurement data, so that the pitch angle can be controlled in consideration of the deformation.

  The learning device 102 of the deformation amount-considered pitch angle command value calculation unit 100 according to the first embodiment of the present invention shown in FIG. 8 has five input parameters: wind speed, rotation speed, yaw error, nacelle inclination angle, and azimuth angle. As a general rule, the model of each time (hereinafter referred to as a time-based model) is configured by the processing of FIG. In, the above-mentioned time-based models are selected using the evaluation signal 112 determined by the evaluation signal determination unit 114. Then, a learning model corresponding to the analysis model 101 is formed from the selected time-based model group considered to be appropriate. This series of processing is realized by utilizing the concept of so-called reinforcement learning.

  In FIG. 20, a series of processes related to the learning device 102 is described as a flowchart. In process step S200, which is the first process in FIG. 20, parameters such as wind speed, rotation speed, yaw error, nacelle tilt angle, and azimuth angle are input. Subsequently, in processing step S201, the evaluation signal determined by the evaluation signal determination unit 114 is input. As a premise, it is assumed that the azimuth angle, the generated power, the blade deformation amount are input, and the blade vibration velocity is calculated and the evaluation signal is determined.

  In the processing step S202, a method for operating the pitch angle is learned, but the processing content here is basically the same as the above-mentioned "basic speed, rotation speed, yaw error, nacelle inclination angle, and azimuth angle. Is configured to obtain a deformation-amount-pitch angle command value by configuring a model at each time (to be referred to as a time-dependent model) by the processing of FIG. The time-based models are selected using the evaluation signal 112 determined by the unit 114. Then, a learning model corresponding to the analysis model 101 is formed from the selected time-based model group that is considered to be appropriate ”. ing. Therefore, according to this processing, the correction information S10 is obtained according to the difference between the pitch angle command value obtained by learning when the same input is made and the pitch angle command value obtained by the analysis model 101.

  In processing step S203, it is determined whether or not the analysis model 101 is in the functional form, and if it is a function, the processing proceeds to processing step S204, and if not, the processing proceeds to processing step S207.

  In processing step S204, the function of the analysis model 101 is updated by the correction information S10 according to the difference between the pitch angle command value obtained by learning and the pitch angle command value obtained by the analysis model 101, and processing step S205 The pitch angle command value obtained by the analysis model 101 is output, and as a result, the pitch angle is controlled in processing step S206.

  In processing step S207, the model is constructed by the learning device 102, and in processing step S208, the pitch angle command value (in this case, the difference between the learning device and the analysis model output is output) from the model in the learning device 102 and the processing step. In S209, the pitch angle command value obtained by the analysis model 101 is added and output, and as a result, the pitch angle is controlled in processing step S206.

  If the operation is performed only in the low wind speed region such as the cut-in wind speed Vin to the wind speed Vd, the pitch angle can be adjusted only by the deformation amount consideration pitch angle command value calculation unit 100 in FIG. Further, when considering operation in a wider wind speed region, as shown in FIG. 9, the command value of the pitch angle control unit 22 of the wind power generation system 1 is a command calculated by the deformation-considered pitch angle command value calculation unit 100. The final pitch angle command value may be determined by adding the values. Here, the pitch angle control unit 22 may calculate the pitch angle command value by adding the command value from the rotation speed control unit 22a and the command value from the torque control unit 22b, or only the rotation speed control unit 22a. The pitch angle command value may be calculated based on Note that FIG. 9 is a block diagram showing an outline of the processing of the operation control unit in the wider wind speed region which is mounted on the controller 11 according to the first embodiment of the present invention.

  As described above, the learning device 102 shown in FIG. 8 obtains the pitch angle command value in consideration of the deformation amount by learning, but regarding this usage method, the analysis is performed as shown in the condition S10 as described above. It may be used for the method of correcting the model characteristics of the model 101, or as shown in the condition S11, the output of the analysis model 101 in the initial state and the output of the analysis model 101 as the output of the learning device 102 after learning are used. You may use it in the form which compensates for the difference between.

  FIG. 10 is a flowchart for creating in advance an analytical model 101 of the generator torque corresponding to the deformation-considered pitch angle.

  In FIG. 10, parameters of wind speed, rotation speed, yaw error, nacelle tilt angle, azimuth angle, and pitch angle are input in processing step S106. In processing step S107, the generated electric power and the generator torque are calculated.

  In processing step S108, it is determined whether or not possible measurement information has been covered. If not, the processing of processing step S106 and processing step S107 is executed again. As a result, the generator torque is searched for the parameters that cover the operating state of the wind turbine. In processing step S109, the generator model torque corresponding to the deformation amount consideration pitch angle is additionally stored in the analysis model storing the pitch angle for the parameters covering the operating state of the wind turbine to store the analysis model. It may be 108.

  FIG. 11: is a figure in the wind power generation system 1 for demonstrating the relationship of the angle of attack with respect to the relative wind speed which flows into the blade element of a certain blade cross section, a pitch angle, and an initial twist angle. As shown in FIG. 11, the rotational speed ω due to the rotation of the blade 115 and the relative wind speed W due to the wind speed V flow into the blade 115. The angle formed by the rotational surface of the blade 115 and the chord length is the sum of the pitch angle θp and the initial twist angle θs of the blade (θp + θs). Further, the angle formed by the relative wind speed W and the chord length is the attack angle α0 of the blade.

  Further, FIG. 12 is a diagram for explaining the relationship when a deformation amount occurs in FIG. 11. When the blade 115 is deformed, as shown in FIG. 12, the relative wind speed changes, and the twist φ is added to the angle formed by the rotating surface and the chord length, and the angle of attack of the blade 115 changes to α1.

  FIG. 13 is a diagram showing the relationship between the angle of attack of the blade cross section and the aerodynamic performance (cross-sectional aerodynamic performance) in the case where a deformation amount occurs in the wind power generation system 1. Therefore, as shown in FIG. 13, since α0 changes to α1, the cross-sectional aerodynamic performance of blade 115 deteriorates. Here, the cross-sectional aerodynamic performance is the quotient of the lift force of the blade 115, the torque and force applied in the rotation direction, or the force applied in the rotation direction of the blade 115 and the force applied in the thrust direction.

  FIG. 14 is a diagram showing an example of the relationship between the wind speed and the force applied in the rotation direction when the deformation amount consideration pitch angle command value calculation unit 100 according to the first embodiment of the present invention is applied and when it is not applied. . As shown in FIG. 14, the force 117 applied in the rotational direction after applying the database can be improved by about 10% on average with respect to the force 116 applied in the rotational direction before applying the database.

  When the first embodiment of the present invention is applied, it is possible to control the pitch angle considering the deformation amount, and further, by utilizing the actual machine operation data to update or correct the pitch angle command value, the power generation is improved. Alternatively, the load can be reduced.

  In the deformation amount consideration pitch angle command value calculation unit 100 of the first embodiment shown in FIG. 5, the physical significance and effect of configuring the analysis model 101 or the learning device 102 as described above are summarized as follows. Is.

  By utilizing the outputs of the wind speed measurement unit 103 and the rotation speed measurement unit 104, it is possible to adjust the pitch angle (blade deformation consideration pitch angle) that maximizes aerodynamic performance in consideration of the deformation amount.

  Furthermore, by utilizing the yaw error measuring unit 105, it is possible to adjust the blade deformation-considered pitch angle that occurs when the wind power generation system 1 is not directly facing the wind direction.

  Further, by utilizing the nacelle inclination angle measuring unit 106, when the wind turbine generator system 1 is installed in a floating body, it is possible to adjust to a blade angle considering the blade deformation that occurs when the rotor 4 tilts back and forth. .

  Since the wind speed measuring unit 103 measures the wind speed in the vicinity of the nacelle 5, it is not possible to consider the effect called wind shear, which increases the wind speed as the altitude increases. Furthermore, the effect of the wind speed near the tower after passing the tower, which is called tower shadow in the downwind type wind turbine, cannot be considered. Therefore, by utilizing the azimuth angle measuring unit 107, it is possible to consider the change in wind speed during one rotation cycle due to wind shear and tower shadow. Therefore, it is possible to adjust the pitch angle to consider blade deformation during one rotation cycle. In this case, each blade can be controlled independently.

  The blade deformation amount measuring unit 109 can measure, for example, an optical fiber sensor or a strain gauge. As a specific example of the optical fiber sensor, the technique described in JP-A-2018-145899 can be used. Light is emitted from a light source, and in an optical fiber sensor arranged on the blade, light having a wavelength corresponding to the amount of change in strain of the blade is reflected by a detector via an optical fiber cable. The detector detects the wavelength of the transmitted reflected light, and the detected reflected light can be converted into the amount of strain corresponding to the wavelength by converting the light intensity into strain.

  In addition, here, from the wind speed measurement unit 103, the rotation speed measurement unit 104, the yaw error measurement unit 105, the nacelle inclination angle measurement unit 106, the generated power measurement unit 108, and the blade deformation amount measurement unit 109 to the deformation amount consideration pitch angle command value calculation unit. The value input to 100 may be the same as the output signal of each measuring unit, or may be a value that has been subjected to filter processing with a predetermined time constant set.

  When configuring the operation control unit of the present invention, it is practical to actually adopt a calculation system and implement it by software. Therefore, the function of the variable speed control unit 21 (pitch angle control unit 22, generator torque control unit 23) in the controller 11 of FIG. 2 or the function of the deformation amount consideration pitch angle command value calculation unit 100 of FIG. It is realized by software by the computer system. In the embodiment, software for some of the main functions is illustrated in FIG. 7, FIG. 8, FIG. 9, FIG. Not all of them are illustrated, but it goes without saying that parts not illustrated here are also realized by software. Further, software processing can also be performed in the measuring instrument or the conversion function portion for processing the output thereof.

  A wind power generation system according to a second embodiment of the present invention will be described with reference to FIG. Note that detailed description of points that are the same as those of the first embodiment will be omitted.

  FIG. 15: is a block diagram which shows the operation control part of the wind power generation system which concerns on Example 2 of this invention. Unlike the first embodiment, the measurement signal 110 includes the azimuth angle correction value generation unit 200, and the correction value of the azimuth angle is input to the deformation amount consideration pitch angle command value calculation unit 100 to calculate the pitch angle command value. Take a configuration.

  The azimuth angle correction value generation unit 200 adds, for example, a value obtained by multiplying the value from the azimuth angle measurement unit 107 by the time constant of the pitch angle driving device multiplied by the rotation speed of the rotation speed measurement unit 104 to obtain the pitch angle command. The azimuth angle is calculated by correcting the influence of the advance of the phase of the azimuth angle from the value calculation to the actual reaching of the pitch angle command value. At this time, the rotational speed may be multiplied by a value that is twice or three times the time constant.

  When the second embodiment of the present invention is applied, power is generated by correcting the deviation between the pitch angle command value at the azimuth angle measurement time and the pitch angle command value to be calculated at the time when the pitch angle command value is actually reached. It is possible to suppress a decrease in efficiency.

  A third embodiment of the present invention will be described with reference to FIG. Note that detailed description of points that are the same as those of the first and second embodiments will be omitted.

  FIG. 16: is a block diagram which shows the operation control part of the wind power generation system which concerns on Example 3 of this invention. Unlike the first and second embodiments, an inverse model 300 of the pitch angle driving device is provided, and the pitch angle command value corrected by the inverse model is added to the pitch angle command value in the first and second embodiments. Then, the final pitch angle command value is determined. The inverse model is created by obtaining the inverse transfer function of the pitch angle driving device by analysis and machine learning based on the past operation data.

  When the third embodiment of the present invention is applied, it is calculated by the measurement information of the arrival time, which is caused by the variation of the measurement information from the time when the pitch angle command value is calculated to the time when the pitch angle command value is actually reached. By correcting the error between the pitch angle command value and the actual pitch angle at the arrival time by utilizing the inverse model, it is possible to suppress the decrease in power generation efficiency.

  The operation control unit of the wind power generation system according to the fourth embodiment of the present invention will be described with reference to FIG. The pitch angle operation control unit according to the fourth embodiment of the present invention is the same as in the first to third embodiments, and thus the description thereof will be omitted.

  In the fourth embodiment, unlike the first to third embodiments, the pitch angle measuring unit 400 is provided, and in addition to the measuring unit, based on the measurement information of the pitch angle measuring unit 400, a generator torque command value from the analysis model 101. To calculate.

  Similarly, in the learning device 102, the function for outputting the generator torque command value is updated based on the measurement signal from the pitch angle measurement unit 400 and the evaluation signal in addition to the measurement unit, and the generator torque command value is corrected. To do.

  As the generator torque command value, only the value calculated by the analysis model 101 may be used, or the value calculated by the analysis model 101 may be added to the value calculated by the generator torque control unit 23 to obtain the final value. The generator torque command value may be determined.

  When the fourth embodiment of the present invention is applied, it is possible to suppress a decrease in power generation efficiency by adjusting the generator torque corresponding to the operation with the deformation amount consideration pitch angle command value.

  The operation control unit of the wind turbine generator system according to the fifth embodiment of the present invention will be described with reference to FIG. Different from the first to fourth embodiments, a mode switching function 500 capable of switching between the power generation operation mode and the power generation standby mode is provided, whereby the deformation amount referred to based on the measurement information during the power generation operation and the power generation standby is considered. Change the pitch angle.

  In addition, since the rotation of the rotor or the generator is stopped during the power generation standby, the rotation speed measurement unit and the generated power measurement unit are not necessary for the measurement information.

  During power generation standby, the pitch angle that minimizes the force applied in the thrust direction is referenced from the analytical model. The learning device 102 updates the function for outputting the pitch angle command value for improving the blade vibration speed based on the state signal of the measurement information and the evaluation signal of the blade vibration speed.

  When the fifth embodiment of the present invention is applied, it is possible to reduce the load applied to the blade by controlling the pitch angle considering the deformation amount during the power generation standby.

  The operation control unit of the wind turbine generator system according to the sixth embodiment of the present invention will be described with reference to FIG. Note that detailed description of points that are the same as those of the first to fifth embodiments will be omitted.

  In the sixth embodiment, a weighting calculation unit 600 is provided in the addition unit of the command value from the deformation-considered pitch angle command value calculation unit 100 and the command value of the pitch angle control unit 22, and weighting is performed for addition. As a result, in the region near the rated operation where the wind speed is high to adjust the energy input by the wind, the pitch angle can be controlled in the vicinity of the deformation-considered pitch angle to suppress a decrease in generated power. The addition method at this time is determined, for example, by the equation (1).

Here, k is a weighting coefficient, θ _{ip_dem} is a finally determined pitch angle command value for the i-th blade, θ _{p_conv} is a command value of the pitch angle control unit, and θ _{ip_opt} is a deformation amount-considering pitch angle command value calculation unit. It is a command value from 100. k is derived from the following equation based on the measured value V of the wind speed, the wind speed V ₁ at which the pitch angle begins to increase, and the wind speed V _{2 at} which the improvement rate of the generated power with respect to the existing control is positive and is the minimum. Note that V ₁ and V ₂ are calculated in advance based on the performance evaluation result.

Based on the derived k, the pitch angle is controlled so as to be considered when the wind speed is lower than V ₁ . When the wind speed is V ₁ or more and less than the wind speed V ₂ , the existing command value is added to the existing command value from the deformation-considered pitch angle, and when the wind speed is V ₂ or more, the existing command value is controlled.

  Through the above embodiment, in the present invention, “a deformation amount considering pitch angle command value calculating unit for obtaining a pitch angle command value considering the deformation amount of the blade is provided, and a pitch angle command of the deformation amount considering pitch angle command value calculating unit is provided. A wind power generation system characterized by changing the pitch angle by giving a value to the pitch angle driving device.

  Furthermore, regarding the pitch angle estimation method, “the wind speed, the rotation speed of the rotor or the generator, the azimuth angle state signal, and the generated power and / or the blade vibration speed determined as the evaluation signal based on the azimuth angle and / or the blade vibration speed are calculated. It is input to the learning device, and the learning device estimates the pitch angle command value for improving the evaluation signal for the state signal, and controls the pitch angle based on the estimated pitch angle command value. "

  As a method of using the learning device, a method of correcting the model characteristics of the analysis model set in the initial state, a method of correcting the difference between the analysis model and the like can be applied.

  Regarding the method of using the deformation-considered pitch angle command value obtained by the learning device or the like, it may be directly given to the pitch angle driving device 8 of the blade 2 or added to the output of the controller 11. Good.

  In addition, in constructing the deformation-considered pitch angle command value calculation unit 100, various configurations can be adopted, and various measures can be adopted depending on the current situation.

1 ... Wind power generation system, 2 ... Blade, 3 ... Hub, 4 ... Rotor, 5 ... Nacelle, 6 ... Generator, 7 ... Wind direction wind speed sensor, 8 ... Pitch angle drive device, 9 ... Tower, 10 ... Power converter, 11 ... Controller, 12 ... Rotational speed sensor, 21 ... Variable speed control part, 22 ... Pitch angle control part, 22a ... Rotational speed control part, 22b ... Torque control part, 23, Generator torque control part, 100 ... Deformation consideration pitch Angle command value calculation unit, 101 ... Analysis model, 102 ... Learner, 103 ... Wind speed measurement unit, 104 ... Rotation speed measurement unit, 105 ... Yaw error measurement unit, 106 ... Nacelle tilt angle measurement unit, 107 ... Azimuth angle measurement unit , 108 ... Generated power measurement unit, 109 ... Blade deformation amount measurement unit, 110 ... Measurement signal, 111 ... Status signal, 112 ... Evaluation signal, 113 ... Blade vibration speed calculation unit, 114 ... Evaluation signal determination unit, 1 5 ... Wing, 116 ... Force applied in rotation direction before application of blade deformation consideration pitch angle command value calculation unit 117 ... Force applied in rotation direction after application of blade deformation consideration pitch angle command value calculation unit, 200 ... Azimuth angle correction value Generation unit, 300 ... Inverse model, 400 ... Pitch angle measurement unit, 500 ... Mode switching unit, 600 ... Weighting calculation unit

Claims (15)

A plurality of blades whose pitch angle can be changed by a pitch angle drive device, a rotor that receives wind from the blades to rotate, and a wind power generation system that includes a generator that generates electric power by using rotational energy of the rotor,
The pitch angle command value calculation unit for obtaining a pitch angle command value considering the deformation amount of the blade is provided, and the pitch angle command value of the deformation amount consideration pitch angle command value calculation unit is given to the pitch angle drive device. A wind power generation system characterized by changing a pitch angle. The wind power generation system according to claim 1,
The deformation amount consideration pitch angle command value calculation unit uses an analysis model modeling the relationship between the measurement signal in the wind power generation system and the pitch angle command value in consideration of the deformation amount, and the measurement signal in the wind power generation system. A wind power generation system comprising a learning device for obtaining a pitch angle command value in consideration of the deformation amount by learning. The wind power generation system according to claim 2,
Correcting the characteristics of the analysis model according to the learning experience of the learning device, and giving the pitch angle command value to the pitch angle drive device when the measurement signal in the wind power generation system is given to the corrected analysis model. A wind power generation system. The wind power generation system according to claim 2,
A wind power generation system, wherein the pitch angle command value from the analysis model and the sum of the pitch angle command value from the learning device are given to the pitch angle drive device. The wind power generation system according to any one of claims 1 to 4,
A pitch angle control unit that determines a pitch angle command value to control the generator torque and the generator rotation speed to respective target values is provided, and the pitch angle command value from the pitch angle control unit and the deformation amount consideration pitch angle command value. A wind power generation system, wherein a pitch angle command value from a calculation unit is given to the pitch angle drive device to change the pitch angle. The wind power generation system according to any one of claims 2 to 4,
The deformation amount-considering pitch angle command value calculation unit is a wind speed, a rotation speed of a rotor or a generator, a state signal of an azimuth angle, and generated electric power and / or determined as an evaluation signal based on the azimuth angle and / or blade vibration speed. Input the blade vibration speed to the learning device,
The wind power generation system, wherein the learning device estimates a pitch angle command value that improves an evaluation signal for the state signal, and controls the pitch angle based on the estimated pitch angle command value. The wind power generation system according to claim 6,
The deformation amount consideration pitch angle command value calculation unit, based on the state signal, outputs the pitch angle control information from the analysis model storing the pitch angle control information considering the blade deformation amount calculated in advance,
A wind power generation system, wherein the learning device improves the analysis model or corrects pitch angle control information based on the analysis model to control the pitch angle based on a calculated pitch angle command value. The wind power generation system according to claim 6 or 7, wherein
The deformation amount consideration pitch angle command value calculation unit, in the case of a first wind speed or higher for starting power generation and a second wind speed or lower up to rated power generation, acquired from the analysis model, in the rotational direction of the blade. A wind power generation system, wherein the pitch angle is controlled based on a pitch angle command value calculated so as to maximize the applied force or torque. The wind power generation system according to any one of claims 6 to 8,
Using a deviation between the target value and the measured value of the rotation speed of the rotor or the generator as an input value, a feedback control unit for calculating pitch angle control information is provided,
Wind power characterized by controlling the pitch angle by the calculated pitch angle command value based on the pitch angle command value from the deformation amount consideration pitch angle command value calculation unit and the pitch angle control information by the feedback control unit. Power generation system. The wind power generation system according to any one of claims 6 to 9,
Using a deviation between the target value of the generator torque and the measured value as an input value, a feedback control unit for calculating pitch angle control information is provided,
The pitch angle is controlled by the calculated pitch angle command value based on the pitch angle command value from the deformation amount consideration pitch angle command value calculation unit and the pitch angle control information by the feedback control unit. Wind power system. The wind power generation system according to any one of claims 6 to 10,
A value obtained by multiplying the rotational speed of the rotor or the generator by the time constant of the pitch angle driving device is added to the azimuth angle, and the added value is used as a status signal of the analysis model and / or the learning device. Wind power system. The wind power generation system according to any one of claims 6 to 11,
A wind power generation system, wherein the pitch angle is adjusted based on a pitch angle command value obtained by correcting the pitch angle command value by an inverse model created from an inverse transfer function of a pitch angle drive device. The wind power generation system according to claim 9 or claim 10,
The pitch angle control information by the analysis model and / or the learning device and the pitch angle control information by the feedback control unit are controlled based on the pitch angle command value calculated by the weighting calculation unit. Wind power system. The wind power generation system according to any one of claims 7 to 13,
A pitch is calculated so as to minimize the thrust direction load of the blade, which is obtained from the analysis model based on the measurement information of the wind speed in the power generation standby mode, including a mode switching unit that switches between the power generation operation mode and the power generation standby mode. A wind power generation system characterized by controlling a pitch angle based on angle control information. The wind power generation system according to any one of claims 1 to 14,
A wind power generation system, wherein the blade has a flexible structure.

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