Air turbine based on oscillating water column wave power generation and its rotating speed control method

Abstract

The application discloses an air turbine based on an oscillating water column type wave energy power generation and a rotating speed control method thereof, and relates to the technical field of wave energy utilization equipment.The air turbine comprises a permanent magnet generator, a static vane wheel, a dynamic vane wheel, a flow guide base, a base connecting plate, a circular cavity installed on an oscillating air chamber, a top sealing plate, a rotating plate and a rotating speed adjusting device installed on one end of the circular cavity close to the oscillating air chamber; and the bottom of the circular cavity is detachably fixedly connected with the base connecting plate.The application can significantly improve the conversion efficiency of wave energy into electric energy by dynamically adjusting the air intake of the air turbine, combining multi-physical field coupling simulation and PD rotating speed closed loop correction algorithm, greatly reduce the rotating speed fluctuation rate to less than or equal to 2%, and enhance the stability and response speed of the system; in addition, the hierarchical control logic enables the device to smoothly operate under different sea conditions, expands the application range, and provides a new efficient solution for the oscillating water column type wave energy power generation technology.

Description

Technical Field

[0001] This invention belongs to the field of wave energy utilization equipment technology, and in particular relates to an air turbine based on oscillating water column wave energy generation and its speed control method. Background Technology

[0002] Current wave energy development technologies (referring to the conversion of wave energy into electrical energy) mainly include oscillating buoy type, wave-overtaking type, and oscillating water column type. Typically, the oscillating buoy type relies on wave energy to propel a buoy, transferring the wave energy to energy conversion devices such as hydraulic motors to generate electricity. The wave-overtaking type directs waves to a higher elevation, allowing the seawater to pass through a turbine at a lower elevation for energy conversion, ultimately converting the seawater's kinetic energy into electrical energy. The oscillating water column type converts wave energy into the kinetic energy of gas, which is then converted into electrical energy through an air turbine to generate electricity.

[0003] Convenient deployment and maintenance are crucial for oscillating water column wave energy air turbine power generation devices. Application No. 202511409398.9 discloses an air turbine power generation device utilizing wave energy. This device includes a floating foundation, an oscillating air chamber, and an air turbine generator body. The air turbine generator body is connected to the oscillating air chamber, which, arranged on the floating foundation, outputs pressurized power generation airflow in conjunction with waves. This invention can be deployed on a floating base, but it is large in size, has a complex internal structure, and is difficult to maintain. It is mainly deployed on large operating platforms that are easy to maintain. Application No. CN111005837B discloses an air turbine and a power generation device, but it suffers from insufficient active control capability of the turbine inlet pressure. Under unstable inlet air pressure, the speed fluctuation rate of traditional air turbines without speed control is ±20%, resulting in relatively low energy conversion efficiency and rotor stall. Summary of the Invention

[0004] The purpose of this invention is to provide an air turbine based on oscillating water column wave energy power generation and its speed control method. By dynamically adjusting the air intake and PD speed closed-loop correction, the problem of low energy conversion efficiency and rotor stall in the prior art of air turbines is solved, thereby improving the system stability and adaptability.

[0005] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: This invention first provides an air turbine for generating electricity using oscillating water column wave energy, including a permanent magnet generator, a stationary impeller, a moving impeller, a guide seat, a base connecting plate, a circular cavity mounted on an oscillating air chamber, a top sealing plate, a rotating plate, and a speed regulating device mounted on one end of the circular cavity near the oscillating air chamber; the bottom of the circular cavity is detachably fixedly connected to the base connecting plate; the top of the circular cavity is sealed to the top sealing plate, i.e., sealant is applied to the interface before bolting; the circular cavity has several first ventilation holes on its periphery near the permanent magnet generator; the upper end of the permanent magnet generator is mounted below the top sealing plate; the rotating plate is configured with... Inside the circular cavity, the upper shaft of the rotating plate passes under the moving impeller and is connected as a whole, and is connected to the output shaft of the permanent magnet generator; the stationary impeller is coaxially mounted inside the circular cavity; the lower shaft of the rotating plate is connected to the upper stepped groove of the stationary impeller through a deep groove ball bearing; a guide shroud pressure plate is coaxially mounted on the lower end of the stationary impeller; the guide seat is bolted to the guide shroud pressure plate; a speed sensor for detecting the rotational speed of the moving impeller is installed through the side wall of the circular cavity; a pressure sensor for detecting the air pressure located between the stationary impeller and the speed regulating device inside the circular cavity is also installed through the side wall of the circular cavity.

[0006] As a preferred embodiment of the present invention, it further includes a power generation indicator light strip; the upper half of the circular cavity has a mounting groove for mounting the power generation indicator light strip.

[0007] As a preferred embodiment of the present invention, the speed adjustment device includes an air intake adjustment plate, a motor, a bearing, a nut, and a motor bracket; the rotating shaft of the air intake adjustment plate is rotatably connected to the wall of the circular cavity through the bearing; the motor bracket is fixed to the outer wall of the circular cavity; the motor output shaft is drivenly connected to the output shaft of one end of the air intake adjustment plate through a coupling; the air intake adjustment plate is installed at the airflow channel of the circular cavity and is used to control the air intake through the turbine by adjusting the opening degree, thereby realizing the dynamic adjustment of the impeller speed; the motor is an adjustment drive component used to drive the air intake adjustment plate to move precisely; the portion of the rotating shaft of the air intake adjustment plate located on the outer side of the circular cavity has an external thread for connection with the nut.

[0008] As a preferred embodiment of the present invention, a handle is installed at the upper end of the top sealing plate.

[0009] As a preferred embodiment of the present invention, the outer wall of the circular cavity located between the speed adjustment device and the flow guide seat is provided with a plurality of rectification windows; a side sealing plate is installed at the outer end of the rectification window, and a silicone pad is installed between the upper and lower ends of the inner side of the side sealing plate through two silicone pad pressure plates.

[0010] As a preferred embodiment of the present invention, the side sealing plate is a rectangular plate structure, and a second ventilation hole is provided on it within the coverage area of ​​the silicone pad.

[0011] This invention also provides a method for controlling the rotational speed of an air turbine based on oscillating water column wave energy power generation, comprising the following steps: S1. The pressure inside the circular cavity and the rotational speed of the impeller are collected in real time by the pressure sensor and the rotational speed sensor, and the aerodynamic characteristic parameters of six aspects, namely, the time-averaged airflow pressure, the root mean square of pressure pulsation, the turbulence intensity, the average airflow velocity, the turbulence integral scale, and the pulsating pressure gradient, are calculated in real time.

[0012] S2. Based on the aerodynamic characteristic parameters collected in step S1, use a multiphysics coupling simulation model for feedforward correction and calculate the optimal target opening of the intake volume regulating plate.

[0013] S3. The intake volume regulating plate is adjusted to the optimal target opening by driving the motor to control the intake volume of the air turbine and realize the dynamic adjustment of the speed of the moving impeller.

[0014] S4. Combining the PD speed closed-loop correction algorithm, the opening of the air volume regulating plate is finely adjusted according to the deviation between the actual speed of the impeller and the rated speed, so as to eliminate speed error and suppress overshoot.

[0015] The calculation method for the aerodynamic characteristic parameters includes: The formula for calculating the hourly average airflow pressure P-mean is:

[0016] In the formula, Average airflow pressure over a period of time, reflecting the average intensity of wave energy; unit: kPa. : Calculation time window (wave characteristic period), unit: s, T value: 2~5s, set according to typical wave period; Real-time airflow pressure at time t, unit: kPa, source: real-time data collected by the pressure sensor; t: time, unit: s; From 0 to Integration within time; Root mean square of pressure pulsation The calculation formula is:

[0017] In the formula, Root mean square of pressure pulsation, unit: kPa; meaning: reflects the amplitude of pressure fluctuation, the larger the fluctuation, the larger the value. : Calculate the time window, Value range: 2–5 seconds; : The real-time pressure at time t, in kPa, is from the pressure sensor; Turbulence intensity The calculation formula is:

[0018] In the formula, Turbulence intensity, dimensionless, meaning: indicates the intensity of airflow pulsation; the larger the value, the more turbulent the flow. : Root mean square of pressure pulsation, kPa; : Average pressure per hour, kPa; This indicates that the absolute value is taken to avoid negative pressure affecting the calculation; average airflow velocity The calculation formula is:

[0019] In the formula, Average airflow velocity, unit: m / s, meaning: the average airflow velocity in the main flow channel within the cavity; Cavity flow channel constant, dimensionless or Meaning: A fixed coefficient determined by the cavity diameter, flow channel area, and impeller structure, calibrated through simulation or experiment; Real-time rotational speed of the impeller, unit: r / min, source: real-time data collected by the aforementioned speed sensor; : Flow channel structure constant.

[0020] Turbulent Integral Scale The calculation formula is:

[0021] In the formula, : Turbulent integral scale, unit: m, meaning: the size that characterizes the large-scale structure of turbulence and reflects the spatial characteristics of wave disturbance; : Average airflow velocity, m / s; : Pressure pulsation integral time scale, unit: s, meaning: the correlation time of pressure pulsation, calculated by the control module based on the autocorrelation function of the pressure signal; Pulsating pressure gradient The calculation formula is:

[0022] In the formula, : Pulsating pressure gradient, unit: kPa / s, meaning: indicates the rate of pressure change, reflecting the intensity of surge impact; Current pressure, in kPa, from the pressure sensor; Pressure at the previous sampling time, in kPa, from the pressure sensor. : Sampling step size (sampling period), unit: s.

[0023] The governing equations of the multiphysics coupled simulation model include a continuity equation and a momentum equation, wherein: The continuity equation is:

[0024] In the formula, : Time partial derivative operator, meaning: describes the rate of change of a physical quantity with time: ρ: air density; unit: kg / m³ ³ Meaning: Fluid medium density within the simulation computational domain; value taken under standard atmospheric conditions. t: time; unit: s; data source: simulation time step and physical time; Divergence operator: describes the spatial convergence / divergence characteristics of a vector field; : Mass flow rate per unit area; U: Airflow velocity vector, unit: m / s, meaning: three-dimensional velocity at any node in the flow field, data source: CFD simulation iterative solution; obtained in the experiment by conversion between the impeller speed and the cavity structure; 0: mass conservation, the right end is 0 when there is no source sink term; The momentum equation is:

[0025] In the formula, : Rate of change of momentum per unit volume over time; : Convection term (momentum convection transport); Tensor product (dyadic vector) represents convective transport in the velocity field; : Pressure gradient term; Gradient operator; P: static pressure of airflow; unit: Pa or kPa; meaning: local static pressure in the flow field; data source: actual measurement by the pressure sensor; solved iteratively by equations in the simulation; : Viscous stress tensor divergence (viscous dissipation term). Viscous stress tensor, unit: Pa, meaning: the internal frictional force generated by the viscosity of air molecules, data source: aerodynamic viscosity μ, taken at room temperature. Given by fluid properties; S: Source term (momentum source / torque source), unit: N / m ³Meaning: The momentum source generated by the rotation of the impeller, the wall boundary, and the movement of the intake regulating plate; Data source: The speed sensor, which is given by the rotating coordinate system MRF / sliding mesh in the simulation; The method for calculating the optimal target opening of the intake volume regulating plate includes: The baseline opening θ-base is determined by the current average hourly airflow pressure. Obtained by looking up a table or interpolating from the simulation model; Three dynamic correction terms are superimposed, including a turbulence intensity correction term. pulsating pressure gradient correction term Turbulent integral scale correction term .

[0026] The formula for calculating the final optimal target opening θ-target is:

[0027] In the formula, Meaning: Optimal target opening of the intake volume regulating plate, unit: ° (degrees); Function: The final angle command output by the control module to the drive motor, directly determining the cross-sectional area of ​​the airflow channel; Source: Calculated in real time by this formula; θ-base Meaning: Baseline opening, unit: ° (degrees); Function: Based on the current average airflow pressure. The basic opening under steady sea conditions is obtained by looking up / interpolating values ​​from the simulation model. Source: Multiphysics Coupled Simulation Model Pre-calculation Database; K1 means: Turbulence intensity correction coefficient, dimensionless, a positive calibration constant, function: to adjust turbulence intensity. The weight of the impact on the opening degree is as follows: the stronger the turbulence, the greater the opening degree correction. Source: pre-calibrated through sea state tests and simulation iterations. Meaning: Turbulence intensity, dimensionless, reflects the severity of airflow pulsation and turbulence; source: calculated from pressure sensor sampling data. K2 Meaning: Pulsating pressure gradient correction coefficient, dimensionless, a positive calibration constant; Function: Adjusts the influence of pressure change rate on opening degree, and copes with surge impact; Source: Pre-calibrated through sea state tests and simulation iterations. Meaning: Absolute value of pulsating pressure gradient, unit: kPa / s; function: characterizes the rate of pressure change, directly reflects the intensity of wave impact; source: calculated from pressure time series differential. K3 Meaning: Turbulence integral scale correction coefficient, dimensionless, positive calibration constant; Function: Adjusts the compensation weight of turbulent structure size on opening degree, adapting to waves of different wavelengths; Source: Pre-calibrated through sea state tests and simulation iterations. Meaning: Turbulent integral scale Unit: m; Function: Characterizes the spatial dimensions of large-scale turbulent structures, reflecting the spatial characteristics of wave disturbances; Source: Calculated from average velocity and integral time scale. ; Meaning: The reciprocal of the integral scale of turbulence. Function: The smaller the turbulent structure, the larger this value, the stronger the aperture compensation, and the better the stability under small-scale turbulence.

[0028] The PD speed closed-loop correction algorithm includes: Proportional Term Used to quickly eliminate steady-state speed error; differential term This is used to suppress speed fluctuations and overshoot; Opening correction increment The calculation formula is:

[0029] In the formula, Meaning: Opening degree correction increment, unit: ° (degrees), function: to adjust the opening degree to the optimal target opening degree. The fine-tuning angle, based on the existing parameters, is used to eliminate speed errors and suppress overshoot. Source: Real-time calculation from this PD control formula; Kp meaning: Proportional coefficient, dimensionless or... Function: To make proportional corrections based on the magnitude of the speed deviation, quickly reducing the difference between the actual speed and the set speed; Source: Calibration and tuning through simulation and experiment. Meaning: Actual speed of the impeller, unit: r / min; function: reflects the current actual operating speed of the turbine; source: collected in real time by the speed sensor. Meaning: Rated set speed, unit: r / min; function: to control the target value, the rated speed of this device. Source: System preset calibration value; Meaning: Speed ​​deviation; Function: Indicates the magnitude and direction of the actual speed deviating from the rated value; Kd Meaning: Differential coefficient, dimensionless or Function: To perform advance damping correction based on the rate of change of rotational speed, suppressing sudden changes in speed, reducing overshoot, and improving response smoothness. Source: Calculated through simulation and experimental tuning. dN / dt Meaning: Rate of change of rotational speed, unit: Function: Reflects the rate of increase / decrease of rotational speed, used to predict fluctuation trends in advance. Source: Calculated from the difference of rotational speed sampling values ​​at adjacent moments.

[0030] The present invention has the following beneficial effects: This invention significantly improves the conversion efficiency of wave energy to electrical energy by adding a speed adjustment device and dynamically adjusting the air intake to stabilize the impeller speed.

[0031] This invention reduces the speed fluctuation rate to ≤±2% by employing multiphysics field coupled simulation and PD speed closed-loop correction algorithm, thereby improving system stability.

[0032] The hierarchical control logic of this invention enables the device to operate smoothly under different turbulence intensities and wave conditions, thus expanding its application range.

[0033] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0034] Figure 1 This is a cross-sectional schematic diagram of the overall structure of an air turbine for generating electricity based on oscillating water column wave energy according to the present invention.

[0035] Figure 2 This is a schematic diagram of a circular cavity.

[0036] Figure 3 This is a structural diagram of the base connecting plate.

[0037] Figure 4 This is a structural diagram of the top sealing plate.

[0038] Figure 5 This is a structural schematic diagram of the side panel.

[0039] Figure 6 This is a schematic diagram of the rotating plate.

[0040] Figure 7 This is a schematic diagram of the stationary impeller.

[0041] Figure 8 This is a cross-sectional view of the stationary impeller.

[0042] Figure 9 This is a schematic diagram of the moving impeller.

[0043] Figure 10 This is a partial sectional view of the moving impeller.

[0044] Figure 11 This is a schematic diagram of the flow guide seat.

[0045] Figure 12 This is a schematic diagram of the speed regulation device.

[0046] Figure 13 This is a structural diagram of the side sealing plate, silicone pad, and silicone pad pressure plate.

[0047] Figure 14-16 This is the control logic flowchart for the speed control method.

[0048] The attached diagram lists the components represented by each number as follows: 1- Circular cavity, 2- Base connecting plate, 3- Top sealing plate, 4- Side sealing plate, 5- Handle, 6- Rotating plate, 7- Stationary impeller, 8- Moving impeller, 9- Flow guide seat, 10- Silicone pad, 11- Flow guide cover pressure plate, 12- Silicone pad pressure plate, 13- Permanent magnet generator, 14- Deep groove ball bearing, 15- Generator indicator light strip, 16- Air intake adjustment plate, 17- Motor, 18- Bearing, 19- Nut, 20- Motor bracket, 21- Pressure sensor, 22- Speed ​​sensor, 101- First ventilation hole, 102- Rectifying window, 401- Second ventilation hole. Detailed Implementation

[0049] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0050] In current oscillating water column wave energy generation devices, the energy conversion efficiency of air turbines is relatively low, or the rotor of the air turbine is prone to stall. Rotor stall refers to the phenomenon where, when the pressure difference between the air-facing and air-repellent sides of the rotor impeller is too large, the airflow within the boundary layer on the air-repellent side of the rotating blades transforms into turbulence, causing a sharp drop in rotor energy conversion efficiency. Therefore, designing an air turbine that can operate stably in the reciprocating airflow generated by an oscillating water column wave energy generation device and designing a method to control the speed of the impeller to achieve higher energy conversion efficiency are of great significance. Specific Implementation Example 1: like Figure 1-12 As shown, an air turbine based on oscillating water column wave energy generation includes a permanent magnet generator 13, a stationary impeller 7, a moving impeller 8, a guide seat 9, a base connecting plate 2, a circular cavity 1 mounted on an oscillating air chamber, a top sealing plate 3, a rotating plate 6, and a speed regulating device mounted on one end of the circular cavity 1 near the oscillating air chamber. The bottom of the circular cavity 1 is detachably fixedly connected to the base connecting plate 2. The top of the circular cavity 1 is sealed to the top sealing plate 3, and the circular cavity 1 has several first ventilation holes 101 on its periphery around the permanent magnet generator 13. The upper end of the permanent magnet generator 13 is mounted below the top sealing plate 3. The rotating plate 6 is disposed inside the circular cavity 1, and the upper end shaft of the rotating plate 6 passes under the moving impeller 8 and is connected to it as a whole, and is connected to the output shaft of the permanent magnet generator 13. The stationary impeller 7 is coaxially mounted inside the circular cavity 1. The lower end shaft of the rotating plate 6 is connected to the upper stepped groove of the stationary impeller 7 through a deep groove ball bearing 14. A guide vane pressure plate 11 is coaxially mounted on the lower end of the stationary impeller 7; the guide seat 9 is bolted to the guide vane pressure plate 11. A speed sensor 22 for detecting the rotational speed of the moving impeller 8 is installed through the side wall of the circular cavity 1. A pressure sensor 21 for detecting the air pressure located between the stationary impeller 7 and the speed regulating device is also installed through the side wall of the circular cavity 1.

[0052] This also includes a power generation indicator light strip 15. The upper half of the circular cavity 1 has a mounting groove for installing the power generation indicator light strip 15. The power generation indicator light strip 15 is used to indicate the stability of power generation.

[0053] The speed regulation device includes an air intake regulating plate 16, a motor 17, a bearing 18, a nut 19, and a motor bracket 20. The rotating shaft of the air intake regulating plate 16 is rotatably connected to the wall of the circular cavity 1 via the bearing 18. The motor bracket 20 is fixed to the outer wall of the circular cavity 1. The output shaft of the motor 17 is driven by a coupling to one end of the output shaft of the air intake regulating plate 16. The air intake regulating plate 16 is installed at the airflow channel of the circular cavity 1 and is used to control the air intake through the turbine by adjusting the opening and closing degree, thereby realizing the dynamic adjustment of the speed of the impeller 8. The motor 17 is an adjustment drive component used to drive the air intake regulating plate 16 to move precisely. The portion of the rotating shaft of the air intake regulating plate 16 located on the outside of the circular cavity 1 has an external thread for connection with the nut 19. A handle 5 is installed at the upper end of the top sealing plate 3 to facilitate force application during installation and disassembly.

[0054] When waves act on the oscillating air chamber, an oscillating airflow is generated and enters the circular cavity 1, driving the impeller 8 installed in the cavity to rotate, which in turn drives the permanent magnet generator 13 connected to the impeller 8 to generate electricity. During this process, the air pressure in the cavity and the speed of the impeller 8 are monitored in real time by the pressure sensor 21 and the speed sensor 22. The optimal opening of the intake volume regulating plate is calculated using a multiphysics field coupling simulation model. The intake volume is dynamically adjusted by the motor 17 driving the intake volume regulating plate 16 to stabilize the speed of the impeller 8. At the same time, the opening of the intake volume regulating plate 16 is finely adjusted by combining the PD speed closed-loop correction algorithm to further eliminate speed error and suppress overshoot, ensuring efficient and stable operation of the system and realizing the conversion of wave energy into electrical energy. Specific Implementation Example 2: Based on Specific Embodiment 1, the difference in this embodiment is as follows: like Figure 1-2 , Figure 5 and Figure 13 As shown, the outer wall of the circular cavity 1, located between the speed regulating device and the guide seat 9, has several rectifier windows 102. A side sealing plate 4 is installed at the outer end of each rectifier window 101, and a silicone pad 10 is installed between the upper and lower inner ends of the side sealing plate 4 via two silicone pad pressure plates 12. The side sealing plate 4 has a rectangular plate structure and a second ventilation hole 401 located within the coverage area of ​​the silicone pad 10.

[0056] The silicone pad 10 is a sealed structure formed by upper and lower double pressure plates. If the Wells turbine principle is not used, one of the silicone pad pressure plates 12 below the silicone pad 10 can be removed, leaving only one 12-silicone pad pressure plate at the top. Therefore, the silicone pad 10 is a sealed unidirectional air intake structure formed by the upper pressure plate. Specifically, the airflow is changed to enter when the silicone pad 10 is open, and impacts the impeller 8 in a unidirectional upward direction to generate electricity. When impacting the impeller 8, the silicone pad 10 is in a closed state. By changing the installation method, the airflow intake direction is changed, thereby realizing the principle of technical solution two.

[0057] This embodiment also discloses a method for controlling the rotational speed of an air turbine based on oscillating water column wave energy power generation, including the following steps: S1. The air pressure in the circular cavity (1) and the real-time rotation speed of the impeller (8) are collected in real time by pressure sensor (21) and speed sensor (22), and the aerodynamic characteristic parameters of six aspects, namely, time-averaged airflow pressure, root mean square of pressure pulsation, turbulence intensity, average airflow velocity, turbulence integral scale and pulsating pressure gradient, are calculated in real time. S2. Based on the aerodynamic characteristic parameters collected in step S1, use a multiphysics field coupled simulation model to perform feedforward correction and calculate the optimal target opening of the intake volume regulating plate. S3. The intake volume adjustment plate (16) is driven by the motor (17) to adjust to the optimal target opening, so as to control the intake volume of the air turbine and realize the dynamic adjustment of the speed of the impeller (8). S4. Combining the PD speed closed-loop correction algorithm, the opening of the air volume regulating plate (16) is finely adjusted according to the deviation between the actual speed of the impeller (8) and the rated speed, so as to eliminate speed error and suppress overshoot.

[0058] The methods for calculating aerodynamic characteristic parameters include: The formula for calculating the hourly average airflow pressure P-mean is:

[0059] In the formula, Average airflow pressure over a period of time, reflecting the average intensity of wave energy; unit: kPa. : Calculation time window (wave characteristic period), unit: s, T value: 2~5s, set according to typical wave period; : t: real-time airflow pressure at time t, unit: kPa, source: collected in real time by pressure sensor (21); t: time, unit: s; From 0 to Integration within time; The formula for calculating the root mean square pressure pulsation P-rms is:

[0060] In the formula, Root mean square of pressure pulsation, unit: kPa; meaning: reflects the amplitude of pressure fluctuation, the larger the fluctuation, the larger the value. : Calculation time window, T value: 2~5s; :t real-time pressure, kPa, from pressure sensor (21); Turbulence intensity The calculation formula is:

[0061] In the formula, Turbulence intensity, dimensionless, meaning: indicates the severity of airflow pulsation; the larger the value, the more turbulent the flow; 𝑃-rms: root mean square pressure pulsation, kPa; 𝑃-mean: time-averaged pressure, kPa; This indicates that the absolute value is taken to avoid negative pressure affecting the calculation; The formula for calculating the average airflow velocity U-mean is:

[0062] In the formula, Average airflow velocity, unit: m / s, meaning: the average airflow velocity in the main flow channel within the cavity; Cavity flow channel constant, dimensionless or Meaning: A fixed coefficient determined by the cavity diameter, flow channel area, and impeller structure, calibrated through simulation or experiment; Real-time rotational speed of the impeller, unit: r / min, source: collected in real time by speed sensor (22); : Flow channel structure constant; Real-time rotational speed of the impeller Turbulent Integral Scale The calculation formula is:

[0063] In the formula, : Turbulent integral scale, unit: m, meaning: the size that characterizes the large-scale structure of turbulence and reflects the spatial characteristics of wave disturbance; : Average airflow velocity, m / s; : Pressure pulsation integral time scale, unit: s, meaning: the correlation time of pressure pulsation, calculated by the control module based on the autocorrelation function of the pressure signal; The formula for calculating the pulsating pressure gradient Gp is:

[0064] In the formula, : Pulsating pressure gradient, unit: kPa / s, meaning: indicates the rate of pressure change, reflecting the intensity of surge impact; : Current pressure, kPa, from pressure sensor (21); : Pressure at the previous sampling time, kPa, from pressure sensor (21). : Sampling step size (sampling period), unit: s.

[0065] The governing equations of the multiphysics coupled simulation model include the continuity equation and the momentum equation, wherein: The continuity equation is:

[0066] In the formula, The time partial derivative operator describes the rate of change of a physical quantity with respect to time. Air density; unit: kg / m³ ³ Meaning: The density of the fluid medium within the simulation calculation domain; value taken under standard atmospheric conditions, ρ = 1.225 kg / m³. ³ t: time; unit: s; data source: simulation time step and physical time; Divergence operator: describes the spatial convergence / divergence characteristics of a vector field; : Mass flow rate per unit area; U: Airflow velocity vector, unit: m / s, meaning: three-dimensional velocity at any node in the flow field, data source: CFD simulation iterative solution; obtained in the experiment by conversion between the impeller speed and the cavity structure; 0: mass conservation, the right end is 0 when there is no source sink term; The momentum equation is:

[0067] In the formula, : Rate of change of momentum per unit volume over time; : Convection term (momentum convection transport); Tensor product (dyadic vector) represents convective transport in the velocity field; : Pressure gradient term; : Gradient operator; P: airflow static pressure; unit: Pa or kPa, meaning: local static pressure in the flow field, data source: measured by pressure sensor (21); solved by iterative equation in simulation; : Viscous stress tensor divergence (viscous dissipation term). Viscous stress tensor, unit: Pa, meaning: the internal frictional force generated by the viscosity of air molecules, data source: aerodynamic viscosity μ, taken as μ = 1.7894 × 10 at room temperature. ⁻5Pa·s, given by fluid properties; S: source term (momentum source / torque source), unit: N / m ³ Meaning: The momentum source generated by the rotation of the impeller, the wall boundary, and the action of the intake regulating plate; Data source: Speed ​​sensor (22), given by the rotating coordinate system MRF / sliding mesh in the simulation; The optimal target opening degree of the intake volume regulating plate is calculated using the following methods: Reference opening The value is determined by looking up a table or interpolating the current time-averaged airflow pressure P-mean from the simulation model; Three dynamic correction terms are superimposed, including a turbulence intensity correction term. pulsating pressure gradient correction term Turbulent integral scale correction term ; The formula for calculating the final optimal target opening θ-target is:

[0068] In the formula, Meaning: Optimal target opening of the intake volume regulating plate, unit: ° (degrees); Function: The final angle command output by the control module to the drive motor, directly determining the cross-sectional area of ​​the airflow channel; Source: Calculated in real time by this formula; θ-base Meaning: Baseline opening, unit: ° (degrees); Function: Based on the current average airflow pressure. The basic opening under steady sea conditions is obtained by looking up / interpolating values ​​from the simulation model. Source: Multiphysics Coupled Simulation Model Pre-calculation Database; K1 means: Turbulence intensity correction coefficient, dimensionless, a positive calibration constant, function: to adjust turbulence intensity. The weighting of the impact on the opening degree is as follows: the stronger the turbulence, the larger the opening degree correction. Source: pre-calibrated through sea state tests and simulation iterations; I-turb meaning: turbulence intensity, dimensionless, reflecting the severity of airflow pulsation and turbulence. Source: calculated from pressure sensor sampling data. K2 Meaning: Pulsating pressure gradient correction coefficient, dimensionless, a positive calibration constant; Function: Adjusts the influence of pressure change rate on opening degree, and copes with surge impact; Source: Pre-calibrated through sea state tests and simulation iterations. Meaning: Absolute value of pulsating pressure gradient, unit: kPa / s; function: characterizes the rate of pressure change, directly reflects the intensity of wave impact; source: calculated from pressure time series differential. K3 Meaning: Turbulence integral scale correction coefficient, dimensionless, positive calibration constant; Function: Adjusts the compensation weight of turbulent structure size on opening degree, adapting to waves of different wavelengths; Source: Pre-calibrated through sea state tests and simulation iterations. Meaning: Turbulent integral scale Unit: m; Function: Characterizes the spatial dimensions of large-scale turbulent structures, reflecting the spatial characteristics of wave disturbances; Source: Calculated from average velocity and integral time scale. ; Meaning: The reciprocal of the integral scale of turbulence. Function: The smaller the turbulent structure, the larger this value, the stronger the aperture compensation, and the better the stability under small-scale turbulence.

[0069] Physical meaning of the formula: This formula uses the baseline aperture θ-base obtained from the simulation model as its core, and superimposes three dynamic correction terms: First correction term: - Compensation for airflow pulsation intensity; Second correction: - Suppress speed fluctuations caused by sudden pressure changes; Third correction: - Adaptable to wave turbulence structures of different scales. By integrating multiphysics field coupled simulation with turbulence characteristic parameters, it achieves advanced, adaptive, and high-precision opening adjustment, keeping the impeller speed stable within the rated range. Compared with traditional threshold control, this is non-obvious and significantly improves power generation stability and control accuracy.

[0070] The PD speed closed-loop correction algorithm includes: Proportional Term The differential term Kd×(dN / dt) is used to quickly eliminate static speed error; the differential term Kd×(dN / dt) is used to suppress speed fluctuations and overshoot. Opening correction increment The calculation formula is:

[0071] In the formula, Meaning: Opening degree correction increment, unit: ° (degrees), function: to adjust the opening degree to the optimal target opening degree. The fine-tuning angle, based on the existing parameters, is used to eliminate speed errors and suppress overshoot. Source: Real-time calculation from this PD control formula; Kp meaning: Proportional coefficient, dimensionless or... Function: To make proportional corrections based on the magnitude of the speed deviation, quickly reducing the difference between the actual speed and the set speed; Source: Calibration and tuning through simulation and experiment. Meaning: Actual rotational speed of the impeller, unit: r / min Function: Reflects the current actual operating speed of the turbine; Source: Real-time data collected by the speed sensor (22); Meaning: Rated set speed, unit: r / min; function: to control the target value, the rated speed of this device. Source: System preset calibration value; Meaning: Speed ​​deviation; Function: Indicates the magnitude and direction of the actual speed deviating from the rated value; Kd Meaning: Differential coefficient, dimensionless or Function: To perform advance damping correction based on the rate of change of rotational speed, suppressing sudden changes in speed, reducing overshoot, and improving response smoothness. Source: Through simulation and experimental tuning and calibration; dN / dt meaning: Rate of change of rotational speed, unit: r / min·s ⁻¹ Function: Reflects the rate of increase / decrease of rotational speed, used to predict fluctuation trends in advance. Source: Calculated from the difference of rotational speed sampling values ​​at adjacent moments.

[0072] This formula is the PD speed closed-loop correction algorithm: proportional term Responsible for quickly eliminating steady-state speed error, causing the actual speed to converge towards the rated speed; differential term It is responsible for suppressing speed fluctuations and overshoot, and provides advanced damping for sudden speed changes caused by surge impacts. By combining simulation feedforward and PD closed-loop feedback, the speed fluctuation rate is reduced from the traditional ±20% to ≤±2%, resulting in smoother regulation, faster response, and significantly higher control accuracy than conventional air pressure threshold control, demonstrating outstanding progress.

[0073] Hierarchical control logic based on simulation and turbulence characteristics: 1. Stable operating conditions:

[0074] →Slightly adjust the opening. Keep ±3 ° Within.

[0075] 2. Moderate turbulence:

[0076] → The opening degree is dynamically adjusted according to the gradient Gp.

[0077] 3. Strong turbulence / surge impact:

[0078] → Proactive suppression, reducing the opening in advance to avoid overspeed.

[0079] 4. Weak wave / low energy:

[0080] → Automatically increases the opening to improve air intake and avoid underspeed.

[0081] Comparison of simulation and experimental data Simulation data:

[0082] Experimental data: Experimental conditions: Table of experimental data on pressure fluctuation and rotational speed stabilization time under wave height of 1~3m. Experimental setup: A modular air turbine for an oscillating float-type wave energy generation device. Judgment criteria: Rated speed 4000 r / min, stable range 3920~4080 r / min (±2%) Detection accuracy: Pressure ±0.05 kPa, Rotation speed ±10 r / min, Time ±0.1 s

[0083] like Figure 14-16 As shown, the control logic flow of the speed control method is as follows: Step 1: System Startup and Data Acquisition After the system is powered on, it first initializes two core sensors—a pressure sensor (21) and a speed sensor (22) installed on the side wall of the circular cavity. The pressure sensor collects the air pressure signal P(t) between the stationary impeller and the speed regulation device in the cavity in real time, and the speed sensor collects the speed N of the moving impeller (8) in real time. These two data sources are the basis for the input of the entire control logic.

[0084] Step 2: Calculate the six aerodynamic characteristic parameters (S1) Based on the collected raw data, the control module calculates six aerodynamic characteristic parameters in real time: average airflow pressure. —The average intensity of wave energy is reflected by integrating the pressure signal over a period of time (T=2~5 seconds, corresponding to a typical wave cycle); the root mean square of pressure pulsation. —Calculate the fluctuation range of pressure deviating from the mean; the greater the fluctuation, the larger the value; turbulence intensity I-turb—using Divide by The following parameters are obtained: dimensionless number (U-mean), larger value indicates more turbulent airflow; average airflow velocity U-mean, calculated by multiplying the channel constant k by the real-time impeller speed N-actual; turbulence integral scale L-turb, multiplied by U-mean and the pressure fluctuation integral time scale T-int, characterizing the spatial size of large-scale turbulence structure; and fluctuation pressure gradient Gp, calculated by subtracting the previous pressure from the current pressure and dividing by the sampling step size. These parameters reflect the rate of pressure change and directly reflect the intensity of surge impact. These six parameters comprehensively describe the temporal and spatial characteristics of airflow under current wave conditions.

[0085] Step 3: Classification of Operating Conditions Based on the calculated turbulence intensity I-turb and turbulence integral scale L-turb, the system enters the four-level classification judgment logic: First-level judgment: If I-turb < 0.15 and L-turb > 2.0D (D is the characteristic dimension of the cavity), it is judged as a stable operating condition. At this time, only a small adjustment within ±3° of the opening is needed; Second-level judgment: If If the flow is classified as moderate turbulence, the flow opening is dynamically adjusted according to the magnitude of the pressure gradient |Gp|. The third-level determination is: if... ≥0.3 or >0.8 kPa / s, judged as strong turbulence or surge impact, in which case an advance suppression strategy is adopted to reduce the opening in advance to avoid impeller overspeed; Fourth level judgment: if none of the above are met, and If the pressure is <0.5 kPa and L-turb <1.0D, it is determined to be a weak wave or low energy condition. In this case, the opening is automatically increased to improve the intake volume and prevent the impeller from stopping due to underspeed. The processing results of the four conditions are finally converged at the same node and proceed to the next step of feedforward calculation.

[0086] Step 4: Multiphysics simulation feedforward calculation of optimal aperture (S2) Based on the graded judgment, the control module calls the multiphysics coupled simulation model (including continuity equation and momentum equation, using MRF rotating coordinate system or sliding mesh method) for feedforward correction and calculates the optimal target opening θ-target of the intake volume regulating plate.

[0087] The calculation formula is:

[0088] in: It is the baseline opening, which is obtained by looking up a table or interpolating a database table through the simulation model based on the current time-averaged pressure P-mean. It represents the basic opening under stable sea conditions. This is a turbulence intensity correction term; the stronger the turbulence, the larger the opening correction amount. It is a pulsating pressure gradient correction term, used to address pressure abrupt changes caused by surge impacts; This is the integral scale correction term for turbulence. The smaller the turbulent structure, the larger this term, and the stronger the compensation, thus improving stability under small-scale turbulence. Three correction coefficients are involved. All values ​​are normal values ​​pre-calibrated through sea state tests and simulation iterations. The core significance of this step is that instead of adjusting only after the engine speed deviates, the optimal opening is calculated in advance based on airflow characteristics, achieving proactive control.

[0089] Step 5: The motor drives the actuator to move (S3) The control module sends the calculated θ-target as an angle command to the motor 17. The motor drives the intake volume regulating plate 16 to rotate around its shaft via a coupling, adjusting it to the target opening. The intake volume regulating plate is installed at the airflow channel of the circular cavity. Changes in the opening directly change the cross-sectional area of ​​the intake volume through the turbine, thereby achieving dynamic adjustment of the speed of the impeller 8.

[0090] Step 6: PD speed closed-loop correction (S4) After the opening is adjusted, the system does not stop there, but enters the PD closed-loop correction stage to further eliminate residual errors. The control module then reads the actual speed from the speed sensor again. With the rated set speed (This device operates at 4000 r / min) Compare and calculate the speed deviation, and simultaneously calculate the speed change rate dN / dt (obtained by the difference between speed sampling values ​​at adjacent times).

[0091] The formula for adjusting the opening increment is:

[0092] Among them: proportional term Correction is made proportionally to the magnitude of the speed deviation; larger deviations require more adjustment, smaller deviations require less adjustment, quickly eliminating steady-state error; differential term The advance damping is based on the rate of change of rotational speed. If the rotational speed is rising rapidly, the opening is reduced in advance even before the set value is reached to suppress overshoot and fluctuations. Kp and Kd are also constants calibrated through simulation and experiment.

[0093] Final opening Then the data is sent to the motor for fine-tuning. This step ensures that even if there are deviations in the feedforward calculations, the closed loop can bring the speed back to near the rated value.

[0094] Step 7: Stability Determination and Looping The system determines that the value is ≤±2%. If yes, it indicates that the impeller speed has stabilized within the rated range, the system enters a stable power generation state, and the power generation indicator light (band 15) illuminates. Simultaneously, continuous monitoring continues, and the system returns to the first step to continue data collection. If no, it indicates that the speed still fluctuates significantly, and the system returns to the second step to recalculate aerodynamic parameters and repeat the feedforward + closed-loop correction process. This cycle is executed continuously with the sensor sampling period as the tick, significantly reducing the speed fluctuation rate from ±20% under traditional single air pressure threshold control to ≤±2%.

[0095] The logic of the entire speed control method is as follows: "first sensing, then classifying, calculating in advance, executing adjustment, closed-loop repair, and cyclic stabilization". The system first senses the changes in air pressure and speed caused by waves through sensors, then uses six aerodynamic parameters to determine the current sea state level, then uses a multiphysics simulation model to calculate the optimal opening degree in advance and execute it, and finally uses the PD algorithm for closed-loop fine adjustment to eliminate errors. The whole process is repeated, so that the impeller can operate stably at around 4000 r / min under various sea conditions, achieving efficient power generation.

[0096] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An air turbine for generating electricity based on oscillating water column wave energy, comprising a permanent magnet generator (13), a stationary impeller (7), a moving impeller (8), a flow guide (9), and a base connecting plate (2), characterized in that: It also includes a circular cavity (1) installed on the oscillating air chamber, a top sealing plate (3), a rotating plate (6), and a speed adjustment device installed on the circular cavity (1) near the oscillating air chamber; The bottom of the circular cavity (1) is detachably fixedly connected to the base connecting plate (2); the top of the circular cavity (1) is sealed to the top sealing plate (3), and the circular cavity (1) is provided with a plurality of first ventilation holes (101) on the periphery of the permanent magnet generator (13); the upper end of the permanent magnet generator (13) is installed below the top sealing plate (3); The rotating plate (6) is disposed inside the circular cavity (1). The upper end shaft of the rotating plate (6) passes through the underside of the moving impeller (8) and is connected as a whole, and is connected to the output shaft of the permanent magnet generator (13). The stationary impeller (7) is coaxially mounted inside the circular cavity (1); the lower end of the rotating plate (6) is connected to the upper end of the stationary impeller (7) via a deep groove ball bearing (14); a flow guide plate (11) is coaxially mounted on the lower end of the stationary impeller (7); the flow guide seat (9) is bolted onto the flow guide plate (11); A speed sensor (22) for detecting the rotational speed of the impeller (8) is installed through the side wall of the circular cavity (1). A pressure sensor (21) for detecting the air pressure inside the circular cavity (1) between the stationary impeller (7) and the speed regulating device is installed through the side wall of the cavity (1).

2. The air turbine based on oscillating water column wave energy power generation according to claim 1, characterized in that, It also includes a power generation indicator light strip (15); the upper half of the circular cavity (1) has a mounting groove for mounting the power generation indicator light strip (15).

3. The air turbine based on oscillating water column wave energy power generation according to claim 2, characterized in that, The speed adjustment device includes an air intake adjustment plate (16), a motor (17), a bearing (18), a nut (19), and a motor bracket (20); the rotating shaft of the air intake adjustment plate (16) is rotatably connected to the wall of the circular cavity (1) through the bearing (18); the motor bracket (20) is fixed to the outer wall of the circular cavity (1); the output shaft of the motor (17) is connected to the output shaft of one end of the air intake adjustment plate (16) through a coupling; the air intake adjustment plate (16) is installed at the airflow channel of the circular cavity (1) and is used to control the air intake through the turbine by adjusting the opening degree, so as to realize the dynamic adjustment of the speed of the impeller (8); the motor (17) is an adjustment drive component used to drive the air intake adjustment plate (16) to move precisely; the part of the rotating shaft of the air intake adjustment plate (16) located on the outside of the circular cavity (1) is provided with an external thread for connection with the nut (19).

4. The air turbine based on oscillating water column wave energy power generation according to claim 3, characterized in that, A handle (5) is installed at the upper end of the top sealing plate (3).

5. The air turbine based on oscillating water column wave energy power generation according to any one of claims 1-4, characterized in that, The outer wall of the circular cavity (1) located between the speed adjustment device and the guide seat (9) is provided with a plurality of rectification windows (102); a side sealing plate (4) is installed at the outer end of the rectification window (101), and a silicone pad (10) is installed between the upper and lower ends of the inner side of the side sealing plate (4) through two silicone pad pressure plates (12); the side sealing plate (4) is a rectangular plate structure, and a second ventilation hole (401) is provided on it within the coverage area of ​​the silicone pad (10).

6. The method for controlling the rotational speed of an air turbine based on oscillating water column wave energy generation according to claim 5, characterized in that, Includes the following steps: S1. The pressure in the circular cavity (1) and the rotation speed of the impeller (8) are collected in real time by the pressure sensor (21) and the rotation speed sensor (22), and the aerodynamic characteristic parameters of six aspects, namely, the average airflow pressure, the root mean square of pressure pulsation, the turbulence intensity, the average airflow velocity, the turbulence integral scale and the pulsating pressure gradient, are calculated in real time. S2. Based on the aerodynamic characteristic parameters collected in step S1, use a multiphysics field coupled simulation model to perform feedforward correction and calculate the optimal target opening of the intake volume regulating plate. S3. The intake volume regulating plate (16) is driven by the motor (17) to adjust to the optimal target opening, so as to control the intake volume of the air turbine and realize the dynamic adjustment of the speed of the impeller (8). S4. Combining the PD speed closed-loop correction algorithm, the opening of the air volume regulating plate (16) is finely adjusted according to the deviation between the actual speed and the rated speed of the impeller (8) to eliminate speed error and suppress overshoot.

7. The method for controlling the rotational speed of an air turbine based on oscillating water column wave energy generation according to claim 6, characterized in that, The calculation method for the aerodynamic characteristic parameters includes: The formula for calculating the hourly average airflow pressure P-mean is: ； In the formula, Average airflow pressure over a period of time, reflecting the average intensity of wave energy; unit: kPa. : Calculation time window (wave characteristic period), unit: s, T value: 2~5s, set according to typical wave period; : t: Real-time airflow pressure at time t, unit: kPa; t: Time, unit: s; From 0 to Integration within time; The formula for calculating the root mean square pressure pulsation P-rms is: ； In the formula, Root mean square of pressure pulsation, unit: kPa; meaning: reflects the amplitude of pressure fluctuation, the larger the fluctuation, the larger the value. : Calculate the time window, Value range: 2–5 seconds; Real-time pressure, kPa; The formula for calculating turbulence intensity I-turb is: ； In the formula, Turbulence intensity, dimensionless, meaning: indicates the intensity of airflow pulsation; the larger the value, the more turbulent the flow. : Root mean square of pressure pulsation, kPa; : Average pressure per hour, kPa; This indicates that the absolute value is taken to avoid negative pressure affecting the calculation; The formula for calculating the average airflow velocity U-mean is: ； In the formula, Average airflow velocity, unit: m / s, meaning: the average airflow velocity in the main flow channel within the cavity; Cavity flow channel constant, dimensionless or Meaning: A fixed coefficient determined by the cavity diameter, flow channel area, and impeller structure, calibrated through simulation or experiment; Real-time rotational speed of the impeller, unit: ; : Flow channel structure constant; Real-time rotational speed of the impeller; The formula for calculating the integral scale of turbulence, L-turb, is as follows: ； In the formula, : Turbulent integral scale, unit: m, meaning: the size that characterizes the large-scale structure of turbulence and reflects the spatial characteristics of wave disturbance; Average airflow velocity ; : Pressure pulsation integral time scale, unit: s, meaning: the correlation time of pressure pulsation, calculated by the control module based on the autocorrelation function of the pressure signal; The formula for calculating the pulsating pressure gradient Gp is: ； In the formula, : Pulsating pressure gradient, unit: Meaning: Indicates the rate of pressure change, reflecting the intensity of surge impact; : Current pressure, kPa, from the pressure sensor (21); Pressure at the previous sampling time, kPa, from the pressure sensor (21). : Sampling step size (sampling period), unit: s.

8. The method for controlling the rotational speed of an air turbine based on oscillating water column wave energy generation according to claim 7, characterized in that, The governing equations of the multiphysics coupled simulation model include the continuity equation and the momentum equation, wherein: The continuity equation is: ； In the formula, The time partial derivative operator describes the rate of change of a physical quantity with respect to time. Air density; unit: Meaning: Fluid medium density within the simulation computational domain; value taken under standard atmospheric conditions. t: time; unit: s; data source: simulation time step and physical time; : Divergence operator, meaning: describes the spatial convergence / divergence characteristics of a vector field; ρU: mass flow rate per unit area; U: airflow velocity vector, unit: Meaning: The three-dimensional velocity of any node in the flow field; obtained in the experiment by converting the speed of the moving impeller and the cavity structure; 0: mass conservation, the right end is 0 when there is no source sink term; The momentum equation is: ； In the formula, : Rate of change of momentum per unit volume over time; : Convection term (momentum convection transport); Tensor product (dyadic vector) represents convective transport in the velocity field; : Pressure gradient term; Gradient operator; P: static pressure of airflow; unit: Pa or kPa, meaning: local static pressure in the flow field; solved iteratively by equations in simulation; τ: Viscous stress tensor divergence (viscous dissipation term); τ: Viscous stress tensor, unit: Pa, meaning: internal friction force generated by the viscosity of air molecules; S: Source term (momentum source / torque source), unit: Pa Meaning: The momentum source generated by the rotation of the impeller, the wall boundary, and the movement of the intake regulating plate.

9. The method for controlling the rotational speed of an air turbine based on oscillating water column wave energy generation according to claim 8, characterized in that, The method for calculating the optimal target opening of the intake volume regulating plate includes: The baseline opening θ-base is determined by looking up a table or interpolating the current time-averaged airflow pressure P-mean from the simulation model; Three dynamic correction terms are superimposed, including a turbulence intensity correction term. pulsating pressure gradient correction term Turbulent integral scale correction term ; The formula for calculating the final optimal target opening θ-target is: ； In the formula, Meaning: Optimal target opening of the intake volume control plate, unit: ° (degrees); θ-base: Baseline opening, unit: ° (degrees); K1: Turbulence intensity correction coefficient, dimensionless, a positive calibration constant; I-turb: Turbulence intensity, dimensionless, reflecting the severity of airflow pulsation and turbulence. K2 means: the pulsating pressure gradient correction coefficient, dimensionless, and a positive calibration constant; Meaning: Absolute value of pulsating pressure gradient, unit: : K3 means: Turbulence integral scale correction coefficient, dimensionless, and a positive calibration constant; L-turb means: Turbulence integral scale unit: m; where, ; Meaning: The reciprocal of the integral scale of turbulence.

10. The method for controlling the rotational speed of an air turbine based on oscillating water column wave energy generation according to claim 9, characterized in that, The PD speed closed-loop correction algorithm includes: Proportional Term The differential term Kd×(dN / dt) is used to quickly eliminate static speed error; the differential term Kd×(dN / dt) is used to suppress speed fluctuations and overshoot. The formula for calculating the opening correction increment Δθ is: ； In the formula, Δθ means: opening correction increment, unit: ° (degree); Kp means: proportionality coefficient, dimensionless or ; Meaning: Actual rotational speed of the impeller, unit: r / min; Meaning: Rated set speed, unit: ; Meaning: Speed ​​deviation; Kd Meaning: Differential coefficient, dimensionless or ; Meaning: Rate of change of rotational speed, unit: .

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