Distributed clutch control method for dual-unit wave energy array

Abstract

The invention discloses a distributed clutch control method for a dual-unit wave energy array. The distributed clutch control method comprises the following steps: carrying out numerical modeling and hydrodynamic analysis on a dual-unit wave energy array model; establishing a time domain motion equation of the dual-unit wave energy array; establishing a state-space equation of the dual-unit wave energy array, replacing a convolution term of the time domain motion equation with the state-space equation, and calculating to obtain a motion state of the dual-unit wave energy array; distributed clutch control is implemented on the dual-unit wave energy array to maximize extraction of energy in waves. According to the method, the overall calculation efficiency of the system is remarkably improved by coordinating operation of the distributed controllers associated with each other, and compared with a traditional single-controller architecture, the method not only optimizes allocation of calculation resources, but also effectively improves the overall energy absorption efficiency of the dual-unit wave energy array, and the energy utilization rate of the dual-unit wave energy array is improved. And higher energy utilization rate and system response flexibility are shown.

Description

Technical Field

[0001] The present invention belongs to the technical field of wave energy power generation, and specifically relates to a distributed clutch control method for a dual-unit wave energy array. Background Art

[0002] With the continuous growth of global energy demand, the development of clean and renewable energy has become a key strategy to address climate change and energy crises. Among them, wave energy has attracted much attention due to its unique advantages. Firstly, wave energy is widely distributed, covering almost all the seas around the world, and can be effectively developed and utilized in many places. Moreover, its energy density is relatively high. Compared with wind energy and solar energy, it can capture more energy under the same area, providing higher efficiency for large-scale power production. In addition, wave energy has strong stability and predictability. Ocean waves never stop day and night and have a constant frequency, enabling it to generate electricity all day long. It is particularly suitable for providing reliable power to areas with difficult energy supply such as remote islands and offshore oil platforms, reducing the dependence on fossil fuels. The diversity and scalability of wave energy technologies further enhance its important position in the future energy structure. By complementing and combining with other renewable energy sources such as wind energy and solar energy, wave energy helps to improve the efficiency and stability of the overall energy system. Therefore, wave energy is not only a model of clean energy but also expected to become the core force in the global energy transformation, playing a key role in addressing environmental problems and promoting sustainable development.

[0003] A mechanical device that converts the kinetic energy or potential energy of ocean surface waves into electrical energy is called a wave energy converter (WEC). Specifically, the mechanical energy of waves is captured through specific energy capture mechanisms (such as oscillating bodies, oscillating water columns, etc.). Then, this mechanical energy is converted into pneumatic energy or hydraulic energy through a power take-off (PTO) system, and then drives a generator to generate electricity. Although various types of wave energy conversion devices have been developed, such as pressure difference, over-the-top, and oscillating types, the wave energy capture efficiency is still relatively low, which is also one of the obstacles hindering the large-scale application of wave energy technologies.

[0004] Currently, researchers have developed various control strategies, such as reactive power control, locking control, and clutch control, to improve the energy extraction efficiency of wave energy conversion devices. These strategies have been successfully applied to individual wave energy conversion devices and have been proven to be one of the effective methods to improve the energy absorption efficiency. However, existing control algorithms have not been applied in wave energy arrays mainly because in wave energy arrays, the synergistic effects between control algorithms and the complex hydrodynamic interactions between wave energy conversion devices must be considered. Such interactions may lead to competition in energy extraction between wave energy conversion devices, thus affecting the overall energy output. Summary of the Invention

[0005] The object of the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a distributed clutch control method for a dual-unit wave energy array. By introducing the additional inertial force effect between wave energy conversion units and the delay function of the radiation effect in the time-domain motion equation, the complex hydrodynamic interaction between the two units is fully considered, and the energy capture of a single wave energy conversion unit is optimized through a local controller, thereby improving the overall capture efficiency of the dual-unit wave energy array.

[0006] The present invention is implemented by adopting the following technical solutions: A distributed clutch control method for a dual-unit wave energy array is proposed, which is characterized by including: S1, numerically modeling the dual-unit wave energy array model and performing hydrodynamic analysis; S2, establishing the time-domain motion equation of the dual-unit wave energy array; an additional inertial force term generated between wave energy conversion units and a delay term of the radiation effect of the motion of a single wave energy conversion unit on its adjacent device are introduced into the time-domain motion equation; S3, establishing the state-space equation of the dual-unit wave energy array, replacing the convolution term of the time-domain motion equation with the state-space equation, and calculating the motion state of the dual-unit wave energy array; S4, implementing distributed clutch control on the dual-unit wave energy array to maximize the extraction of energy from waves, including: Defining respective Hamiltonian functions for the two wave energy conversion units in the dual-unit wave energy array ; where is the motion equation of a single wave energy conversion unit in the dual-unit wave energy array, is the motion state of the dual-unit wave energy conversion array, is the control command; is the objective function, representing the functional capture of a single wave energy conversion unit, is the control command for controlling a single wave energy conversion unit; is the PTO damping coefficient of a single wave energy conversion unit; is the motion speed of a single wave energy conversion unit; is the Lagrange multiplier; Solving the Hamiltonian function according to the control equation of the Lagrange multiplier, and obtaining the control criterion for distributed clutch control according to the solution result: and ; m1 and m2 are the masses of the two wave energy conversion units respectively; , are the added masses generated by the self-motion of a wave energy conversion unit respectively.

[0007] In some embodiments of the present invention, the time-domain motion equation for establishing a dual-unit wave energy array is: , ; Wherein, 11 and 22 are respectively the added masses generated by the self-motions of the two wave energy conversion units, 12 and 21 are respectively the added masses generated by the motion of one wave energy conversion unit in the heaving direction on the other wave energy conversion unit; x1, x2, are respectively the displacements, velocities and accelerations of the two wave energy conversion units; is the delay function representing the radiation interaction, is the radiation damping, respectively represent the self-radiation delay functions of the two wave energy conversion units, indicating the historical influence of the radiation waves generated by the self-motions of the units on their own velocities; respectively represent the delay functions of the radiation actions of the motion of one wave energy conversion unit on the other wave energy conversion unit; K is the hydrostatic restoring stiffness; is the wave excitation force received by the first wave energy conversion unit, is the wave excitation force received by the second wave energy conversion unit, wherein, represents taking the real part of the complex function, represents the transfer function of the wave excitation force, represents the amplitude of the regular wave component j, represents the frequency of the regular wave component j, represents the random phase of the regular wave component j; respectively represent the reaction forces provided by the PTO systems of the two wave energy conversion units, and c represents the damping coefficient of the PTO system.

[0008] In some embodiments of the present invention, the state-space equation established in S3 is: ; Wherein, represents the n×1 dimensional state variable, , , respectively represent the n×n dimensional, n×1 dimensional, 1×n dimensional state-space matrices.

[0009] In some embodiments of the present invention, S3 includes: Substituting the established state-space equation into the time-domain motion equation and defining new state variables , transform the time-domain motion equation into a linear differential equation: ; ; ; ; ; and are respectively the net water restoration stiffness of the wave energy conversion unit; ; ; The motion state X of the dual-unit wave energy array is obtained by solving using the Runge-Kutta method.

[0010] In some embodiments of the present invention, S3 includes: Use the linear differential equation to approximate in the state space equation; where the linear differential equation is: ; Perform Laplace transform on the linear differential equation, and then perform Fourier transform to obtain: ; Perform Fourier transform on the delay function representing radiation interaction: ; Combine the two Fourier transform results to obtain: , and perform calculations on it to obtain: , ; where, are respectively radiation damping and added mass, calculated by hydrodynamic software; According to calculate p and q, and then obtain , , .

[0011] In some embodiments of the present invention, S4 includes: Solve the Hamiltonian function according to the control equation of the Lagrange multiplier to obtain: , , ; Obtain the control criterion for distributed clutch control according to the solution result.

[0012] In some embodiments of the present invention, during the process of solving the Hamiltonian, the equation of motion is integrated forward from 0 to T, and the control equation is integrated backward from T to 0, including: 1. At simulation is performed. By integrating the equation of motion forward from t = 0 to t = T, the motion state X of the dual-unit wave energy array is obtained; 2. Determine the Lagrange multiplier by integrating the control equation backward from t = T to t = 0 ; 3. Given the motion state vector X and the Lagrange multiplier to determine the control sequence to maximize the Hamiltonian; 4. Use the updated control sequence iterative process until the control sequence converges.

[0013] In some embodiments of the present invention, the damping coefficient of the PTO in step S2 is optimized using the following formula: ; where is the radiation damping, m is the mass of a single wave energy conversion unit, is the added mass.

[0014] Compared with the prior art, the advantages and positive effects of the present invention are as follows: The distributed clutch control method for a dual-unit wave energy array proposed by the present invention fully considers the complex hydrodynamic interactions between wave energy conversion devices in the array in the designed time-domain equation of motion, and at the same time has high practicability and is convenient to implement in actual physical devices. The present invention significantly improves the overall computational efficiency of the system by coordinating the operation of two interrelated distributed controllers. Compared with the traditional single-controller architecture, this method not only optimizes the allocation of computing resources but also effectively improves the overall energy absorption efficiency of the wave energy converter, showing higher energy utilization and system response flexibility.

[0015] After reading the detailed description of the embodiments of the present invention in conjunction with the accompanying drawings, other features and advantages of the present invention will become clearer. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 is a schematic diagram of the steps of the distributed clutch control method for a dual-unit wave energy array proposed by the present invention; Figure 2 This is a schematic diagram of the overall structure of the dual-unit wave energy array in the present invention; Figure 3 This is a schematic diagram of the numerical simulation model of the dual-unit wave energy array in the present invention; Figure 4 This is a schematic diagram of the distributed clutch control process in the present invention; Figure 5 This is a schematic diagram of the distributed clutch control principle in the present invention; Figure 6 This is a comparison chart of the wave energy capture efficiency of the distributed clutch control method shown in the present invention and the existing uncontrolled and independent control algorithms. Specific embodiments

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0019] As Figure 1 shown, the distributed clutch control method for the dual-unit wave energy array proposed by the present invention is as follows: S1: Numerically model the dual-unit wave energy array model and perform hydrodynamic analysis.

[0020] The dual-unit wave energy array consists of two identical and coordinated oscillating buoy type wave energy conversion units. The oscillating buoy type wave energy conversion unit is a device that captures the kinetic energy of waves based on the reciprocating motion of the buoy with the waves, and then drives a generator to generate electricity through a power take-off (PTO) system. The buoy, connecting rod, and PTO system are its main components. Among them, the buoy is connected to the PTO system through a connecting rod. The PTO system mainly includes hydraulic type, mechanical transmission type, hydraulic type, pneumatic type, linear motor type, and hybrid hydraulic type, etc. The present invention selects a hydraulic PTO system, which mainly includes a hydraulic cylinder, a hydraulic motor, and a generator. The piston rod of the hydraulic cylinder is connected to the connecting rod, and the hydraulic cylinder drives the hydraulic motor to work, and the hydraulic motor drives the generator to generate electricity.

[0021] Furthermore, the working principle of the oscillating buoy wave energy conversion unit is as follows: Under the action of the periodic motion of the waves, the buoy drives the piston in the hydraulic cylinder to reciprocate vertically through the connected connecting rod. This reciprocating motion increases the oil pressure by compressing and releasing the hydraulic oil in the hydraulic cylinder, thereby converting the mechanical energy of the waves into hydraulic energy. Subsequently, the high-pressure hydraulic oil flows through the pipeline to drive the hydraulic motor, and the hydraulic motor further converts the hydraulic energy into rotational mechanical energy (i.e., the torque and speed of the output shaft). The rotational motion of the output shaft then drives a three-phase permanent magnet synchronous generator, whose working principle is based on the law of electromagnetic induction. When mechanical energy causes the rotor inside the generator to rotate, the permanent magnets installed on the rotor also rotate, cutting the magnetic field in the stator coils. Since the stator coils are composed of three-phase coils, the rotating magnetic field of the rotor generates three-phase alternating current with a phase difference of 120° in each coil. The characteristic of this power generation method is that the rotational speed of the rotor is synchronized with the frequency of the output current, ensuring a stable output of the current. At the same time, since the permanent magnets do not require an external excitation source, the three-phase permanent magnet synchronous generator has high efficiency, a simple structure, and low maintenance costs, making it very suitable for the long-term operation of the wave energy conversion unit. This entire process achieves an efficient conversion from wave mechanical energy to electrical energy.

[0022] In the present invention, in combination with Figure 2 As shown, the dual-unit wave energy array consists of two identical point-absorbing wave energy conversion units (the first wave energy conversion unit and the second wave energy conversion unit); the wave energy conversion unit is a unit that converts wave energy into electrical energy, mainly composed of a buoy 11, a connecting rod 12, and a PTO 13. The buoy 11 adopts a cylindrical floating body with a radius of 2.5 m and a draft of 5 m. The PTO 13 adopts a hydraulic PTO system, mainly composed of a piston rod, a hydraulic cylinder, a hydraulic motor, and a generator. The piston rod of the hydraulic cylinder is connected to the connecting rod 12, and the hydraulic cylinder drives the hydraulic motor to act, and the hydraulic motor drives the generator to generate electricity; the buoy 11 reciprocates in the heaving direction under the action of the waves and is connected to the PTO 13 through the connecting rod 12. The connecting rod 12 drives the piston of the hydraulic cylinder to perform heaving motion in the heaving direction, increasing the pressure of the hydraulic oil in the hydraulic cylinder cavity. This process converts mechanical energy into hydraulic energy; the hydraulic oil then drives the hydraulic motor, converting the pressure energy of the liquid in the pipeline into the mechanical energy (torque and speed) of the output shaft, and then driving the rear-end generator to generate electricity. The generator uses existing equipment: a three-phase permanent magnet synchronous motor.

[0023] In combination with Figure 3As shown, the present invention uses the GeniE module of the SESAM software to establish only the numerical model of the part below the waterline of the dual-unit wave energy array. In the GeniE module, first establish a numerical model of the dual-unit wave energy array with a radius of 2.5 m and a draft of 5 m, and define the wet surface of the dual-unit wave energy array. Then, load the wet surface of the dual-unit wave energy array. After the loading, perform the mesh division. Finally, through calculation, a.fem file can be obtained and imported into the HydroD module. In the HydroD module, after completing a series of basic information such as defining the wave direction, wave frequency, and panel model, the hydrodynamic parameters of the wave energy conversion unit can be calculated. The hydrodynamic parameters here mainly refer to the added mass, radiation damping, and the first-order wave force transfer function.

[0024] S2: Establish the time-domain motion equation of the dual-unit wave energy array; an additional inertial force term generated by the interaction between the wave energy conversion units and a delay term of the radiation effect of the motion of a single wave energy conversion unit on its adjacent device are introduced in the time-domain motion equation.

[0025] Adopt a right-handed coordinate system fixed on the earth, with the coordinate system center fixed on the mean sea level. The Z-axis is positive upward, and the X-axis is along the direction of wave propagation.

[0026] Based on the impulse response theory, the time-domain motion equation of the dual-unit wave energy array is established as shown in formulas (1) and (2): (1) (2)

[0027] Among them, m1 and m2 are the masses of the two wave energy conversion units respectively; 11 and 22 are the added masses generated by the self-motions of the two wave energy conversion units respectively, 12 and 21 are the added masses generated by the motion of one wave energy conversion unit in the heaving direction on the other wave energy conversion unit respectively; x1, x2, are the displacements, velocities, and accelerations of the two wave energy conversion units respectively; is a delay function representing the radiation interaction, is the radiation damping, represent the self-radiation delay functions of the two wave energy conversion units respectively, indicating the historical influence of the radiation wave generated by the self-motion of the unit on its own velocity; represent the delay functions of the radiation effect of the motion of one wave energy conversion unit on the other wave energy conversion unit respectively; K is the hydrostatic restoring stiffness. F wave,1and F wave,2 are the wave exciting forces of the first wave energy conversion unit and the second wave energy conversion unit respectively, and the calculation formulas are as follows: (3) (4) Wherein, represents taking the real part of the complex function, represents the transfer function of the wave exciting force, represents the amplitude of the regular wave component j, represents the frequency of the regular wave component j, represents the random phase of the regular wave component j; respectively represent the reaction forces provided by the two wave energy conversion units from the PTO system, and c represents the damping coefficient of the PTO system.

[0028] The linear damping coefficient of the PTO can be optimized by using formula (5): (5) Wherein, is the radiation damping, is the mass of a single wave energy conversion unit, is the added mass.

[0029] S3: Establish the state space equation of the dual-unit wave energy array, replace the convolution term in the time-domain motion equation with the state space equation, and calculate the motion state of the dual-unit wave energy array.

[0030] Replace the convolution term in the time-domain motion equation of the dual-unit wave energy array in step S2 with the state space equation to facilitate the implementation of the control algorithm.

[0031] The state space equation is as shown in formula (6): (6) Use the linear differential equation to approximate in formula (6), and the linear differential equation is as shown in formula (7): (7) Combining formula (6) and (7), formula (8) can be obtained: ; ; ; (8) Wherein, represents the n×1 dimensional state variable, , , are used to approximate the convolution terms, representing the state space matrices of n×n dimension, n×1 dimension, and 1×n dimension respectively, and their expansion formula (8) is calculated by the system identification method.

[0032] Specifically, first perform the Laplace transform on the linear differential equation (7) to obtain: (9) Perform the Fourier transform on the delay function representing the radiation interaction, that is, formula (2), to obtain: (10) Then perform the Fourier transform on (9) to obtain: (11) Combining formula (10) and (11), we get: (12) Calculate (12) to obtain: , (13) Among them, are the radiation damping and added mass respectively, calculated by the hydrodynamic software Hydrod, and then calculate p and q according to formula (13), and further obtain , , .

[0033] Substitute the state space equation (6) of the dual-unit wave energy array into its time-domain motion equation (1), and use a new state variable: (14) Rewrite the time-domain motion equation of the dual-unit wave energy array into a linear differential equation: (15) 、 are the motion states of the two wave energy conversion units respectively. Then formula (15) is specifically: ; where ; ; ; ; and are the net water restoration stiffness of the wave energy conversion unit respectively; ; 。

[0034] Then, the fourth-order Runge-Kutta method is used to solve (15) to obtain the motion state of the dual-unit wave energy array.

[0035] S4: Implement distributed clutch control on the dual-unit wave energy array to maximize the extraction of energy from waves.

[0036] The goal of distributed control is to maximize the energy capture of each wave energy conversion unit separately, so as to optimize their sum.

[0037] When the phase of the float velocity is consistent with the phase of the wave excitation force, the energy capture of the wave energy conversion unit will reach the maximum. The innovative distributed clutch control algorithm of the present invention mainly optimizes the control command to control the float, as Figure 4 shown, the control actions mainly include loading ( ) and unloading ( ) each PTO system in the dual-unit wave energy array, so that the phase of the float velocity is consistent with the phase of the wave excitation force, maximizing the energy capture of each wave energy conversion device, and further maximizing the energy capture of the dual-unit wave energy array.

[0038] Specifically, the two wave energy conversion units in the dual-unit wave energy array are regarded as two independent single pedals, and clutch control is applied to the two independent wave energy conversion units respectively, that is, the movement of the float is controlled by their respective controllers. The controllers do not work alone, but work in a coordinated manner, that is, the two local controllers communicate and share information at each time step, exchange the movement state and the wave excitation force information of their respective wave energy conversion units, and jointly search for the optimal control command to control the movement of the float, so that the phase of the velocity of their respective floats is consistent with the phase of the wave excitation force, so that the power capture of the two independent wave energy conversion units reaches the maximum respectively, and finally the energies of the two wave energy conversion units are superimposed to make the sum reach the maximum.

[0039] The goal of implementing distributed control on the dual-unit wave energy array is to maximize the energy capture of each wave energy array, which is a constrained optimization problem, and the constraint criterion is the motion equation of the dual-unit wave energy array.

[0040] In the present invention, by introducing the Lagrange multiplier, the constraint condition and the objective function are combined into a Hamiltonian function H, the constraint of the state equation is included in the optimization problem, and the complex constrained optimization problem is transformed into an unconstrained optimization problem. For distributed control, each wave energy conversion unit in the dual-unit wave energy array has its own Hamiltonian function H, as shown in formula (16): (16) Among them, is the motion equation of a single wave energy conversion unit in the dual-unit wave energy array; J is the objective function, representing the energy capture of a single wave energy conversion unit, and its expression is as follows: (17) is the Lagrange multiplier, following the control equation (18): (18) Furthermore, combining formula (15), the Hamiltonian function H can be written as formula (19): (19) Among them, represents the control command for controlling the first wave energy conversion unit, represents the control command for controlling the second wave energy conversion unit, c1 represents the PTO damping coefficient of the first wave energy conversion unit, c2 represents the PTO damping coefficient of the second wave energy conversion unit, respectively represent the motion speeds of the first wave energy conversion unit and the second wave energy conversion unit.

[0041] By solving the Hamiltonian function (19) through the control equation (18), we get: , , (20) According to (20), the control criterion for distributed clutch control can be obtained: and (21) As Figure 5 shown, according to the Pontryagin maximum principle, when the Hamiltonian is at its maximum, there exists an optimal control sequence .

[0042] It should be noted that although the overall constraint criterion of formula (21) corresponds to a single wave energy conversion unit, the determination of the state vector X is based on the dual-unit wave energy array. That is to say, each local controller coordinates its work through its own information sharing and communication, predicts the state of the future wave energy conversion device, and then derives the control command separately. The development of distributed control is based on the observation that is much larger than . This indicates that although the hydrodynamic interaction is crucial for the analysis of the state vector X, it can be ignored in the control criterion when the state vector X has been correctly calculated. Therefore, assuming that all non-diagonal terms are zero, the hydrodynamic interaction is ignored in the constraint criterion.

[0043] It should be noted that although the motion equation and the control equation of the dual-unit wave energy array are both first-order partial differential equations, they cannot be solved in parallel because the two formulas are at different initial times. Specifically, the motion equation is integrated forward from 0 to T, and the control equation is integrated backward from T to 0. An interactive optimization algorithm is used to solve this problem. First, a simulation is carried out at to obtain the motion without control action by integrating the motion equation forward from t = 0 to t = T. Subsequently, the Lagrange multiplier is determined by integrating the control equation backward from t = T to t = 0. Finally, given the state vector X and the Lagrange multiplier to determine the control sequence to maximize the Hamiltonian. The iterative process of the updated control sequence is used until the control sequence converges.

[0044] In a specific embodiment of the present invention, for an array system composed of two wave energy conversion devices, numerical simulations of the wave energy conversion devices under three control methods (uncontrolled, independent control, and centralized control) are carried out to compare their energy capture performances. The incident wave is described by the JONSWAP spectrum, and a wave condition is selected, with an effective wave height of 1.4 m and a spectral peak period of 5.5 s. The total duration of the simulation is 3600 s, and the sampling time interval is 0.01 s.

[0045] The wave energy capture efficiencies under the uncontrolled, independent control, and centralized control algorithms are as Figure 6 shown. In the uncontrolled case, the energy capture efficiency of the array wave energy conversion device within 1 hour is approximately 12 kW; in the independent control mode (i.e., the clutch control algorithm is separately implemented for the two wave energy conversion devices, as Figure 5 shown), its energy capture efficiency is increased to approximately 31 kW; while when the distributed control algorithm is adopted, the energy capture efficiency is further increased to approximately 42 kW. Compared with the uncontrolled state, the distributed control algorithm increases the energy capture efficiency by 250%; compared with the independent control mode, it is increased by 35.5%. It can be seen that the distributed control algorithm proposed by the present invention significantly improves the wave energy capture efficiency and fully demonstrates excellent performance advantages.

[0046] It should be noted that in the specific implementation process, the above control part can be implemented by a processor in hardware form executing computer-executable instructions in software form stored in the memory, which will not be elaborated here, and the programs corresponding to the actions executed by the above control circuit can all be stored in the computer-readable storage medium of the system in software form, so as to facilitate the processor to call and execute the operations corresponding to each module above.

[0047] The computer-readable storage medium described above may include volatile memory, such as random access memory; it may also include non-volatile memory, such as read-only memory, flash memory, hard disk or solid-state drive; it may also include a combination of the above types of memory.

[0048] The processor mentioned above may also be a general term for multiple processing elements. For example, the processor may be a central processing unit, or it may be other general-purpose processors, digital signal processors, application-specific integrated circuits, field-programmable gate arrays or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc., and may also be a dedicated processor.

[0049] It should be noted that the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by those of ordinary skill in the art within the scope of the essence of the present invention should also fall within the protection scope of the present invention.

Claims

1. A distributed clutch control method for a dual-unit wave energy array, characterized in that Including: S1, numerically model the dual - unit wave energy array model and conduct hydrodynamic analysis; S2, establish the time - domain motion equation of the dual - unit wave energy array; in the time - domain motion equation, introduce the additional inertial force term generated mutually between wave energy conversion units and the delay term of the radiation effect of the motion of a single wave energy conversion unit on its adjacent device; S3, establish the state - space equation of the dual - unit wave energy array, replace the convolution term of the time - domain motion equation with the state - space equation, and calculate the motion state of the dual - unit wave energy array; S4, implement distributed clutch control on the dual - unit wave energy array to maximize the extraction of energy from waves, including: Define the Hamiltonian functions for the two wave energy conversion units in the dual-unit wave energy array respectively ; where is the motion equation of a single wave energy conversion unit in the dual-unit wave energy array is the motion state of the dual-unit wave energy conversion array is the control command is the objective function, representing the power capture of a single wave energy conversion unit is the control command for controlling a single wave energy conversion unit is the PTO damping coefficient of a single wave energy conversion unit is the motion speed of a single wave energy conversion unit is the Lagrange multiplier Solve the Hamiltonian function according to the control equation of the Lagrange multiplier, and obtain the control criterion for distributed clutch control according to the solution result: and ; m1 and m2 are the masses of two wave energy conversion units respectively; 、 are the added masses generated by the self - motion of a wave energy conversion unit respectively.

2. The distributed clutch control method for a dual-unit wave energy array according to claim 1, wherein The time - domain motion equation of the dual - unit wave energy array established in step S2 is: ， ； Among them, 11 and 22 are respectively the added masses generated by the self - motion of the two wave energy conversion units, 12 and 21 are respectively the added masses generated by the motion of one wave energy conversion unit in the heaving direction on the other wave energy conversion unit; x1, x2, are respectively the displacements, velocities and accelerations of the two wave energy conversion units; is the delay function representing the radiation interaction, is the radiation damping, respectively represent the self - radiation delay functions of the two wave energy conversion units, indicating the historical influence of the radiation waves generated by the unit's own motion on its own velocity; respectively represent the delay functions of the radiation action of the motion of one wave conversion unit on the other wave conversion unit; K is the hydrostatic restoring stiffness; is the wave excitation force received by the first wave energy conversion unit, is the wave excitation force received by the second wave energy conversion unit, among which, represents taking the real part of the complex function, represents the transfer function of the wave excitation force, represents the amplitude of the regular wave component j, represents the frequency of the regular wave component j, represents the random phase of the regular wave component j; respectively represent the reaction forces provided by the PTO systems of the two wave energy conversion units, and c represents the damping coefficient of the PTO system.

3. The distributed clutch control method for a dual-unit wave energy array according to claim 1, characterized in that The state - space equation established in S3 is: ； Among them, represents an n×1 dimensional state variable, , , respectively represent an n×n dimensional, an n×1 dimensional, and a 1×n dimensional state space matrix.

4. The distributed clutch control method for a dual-unit wave energy array according to claim 3, wherein S3 Including: Substitute the established state-space equations into the time-domain motion equations and define new state variables , and transform the time-domain motion equations into linear differential equations: ; wherein, ； ； ； ； ； ; and are respectively the hydrostatic restoring stiffness of the wave energy conversion unit; Use the Runge - Kutta method to solve for the motion state X of the dual - unit wave energy array.

5. The distributed clutch control method for a dual-unit wave energy array according to claim 4, characterized in that, S3 includes: Using a linear differential equation to approximate in the state space equation ; where the linear differential equation is: ; Perform Laplace transform on the linear differential equation, and then perform Fourier transform to obtain: ； Perform Fourier transform on the delay function representing radiation interaction: ； Combine the two Fourier transform results to obtain: , and calculate it to obtain: ， ; wherein, are radiation damping and added mass respectively, which are calculated by hydrodynamic software; According to calculated to obtain p and q, and further obtain , , .

6. The distributed clutch control method for a dual-unit wave energy array according to claim 4, characterized in that S4 Including: Solve the Hamiltonian function according to the control equation of the Lagrange multiplier to obtain: ， ， ； Obtain the control criterion for distributed clutch control according to the solution result.

7. The distributed clutch control method for a dual-unit wave energy array according to claim 6, characterized in that, During the solution process of the Hamiltonian, the motion equation is integrated forward from 0 to T, and the control equation is integrated backward from T to 0, including: At simulation is carried out. By integrating the motion equation forward from t = 0 to t = T, the motion state X of the dual-unit wave energy array; The Lagrange multipliers are determined by integrating the governing equations backward from t = T to t = 0 ; Given the motion state vector X and the Lagrange multiplier to determine the control sequence to maximize the Hamiltonian; Iterate the process using the updated control sequence until the control sequence converges.

8. The distributed clutch control method for a dual-unit wave energy array according to claim 1, wherein In step S2, the damping coefficient of the PTO is optimized using the following formula: ; wherein, is the radiation damping, m is the mass of the wave energy conversion unit, is the added mass.

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