Jellyfish biomimetic wave energy device, power generation method and design method

Abstract

The application provides a jellyfish bionic wave power generation device, a power generation method and a design method, and belongs to the technical field of marine renewable energy utilization. The device comprises a bionic jellyfish umbrella cover, a flexible framework, a full-seawater hydraulic system, a dielectric elastomer film and a power conversion system; the bionic jellyfish umbrella cover is in a radial symmetry structure to capture waves without directional restriction; the flexible framework drives the umbrella cover to contract and expand; the full-seawater hydraulic system drives a permanent magnet synchronous generator to generate power by taking seawater as a working medium; the dielectric elastomer film generates power by using the capacitance change caused by film deformation; and the power conversion system outputs after converging two-way electric energy. By using the application, the problems of low power generation efficiency and low stability in the prior art can be solved.

Description

Technical Field

[0001] This invention relates to the field of marine renewable energy utilization technology, and in particular to a jellyfish-inspired wave energy power generation device, power generation method and design method. Background Technology

[0002] Wave energy is one of the clean and renewable energy sources in the ocean with high energy density and wide distribution. The theoretical total exploitable wave energy globally is about 2 terawatts (about 2 × 10¹² watts). However, due to the complex ocean environment and the inherent characteristics of waves, such as low frequency, high thrust, and variable amplitude, efficient, reliable, and low-cost wave energy conversion technologies have not yet been commercialized on a large scale.

[0003] Existing wave energy conversion devices mainly include pendulum wave energy conversion devices, float-type devices, and oscillating water column devices. Pendulum devices utilize the reciprocating oscillation of a pendulum body driven by waves to drive a generator; float-type devices utilize the rise and fall of a float body with the waves to drive a transmission mechanism to generate electricity; oscillating water column devices utilize the reciprocating airflow generated by wave oscillation within an air chamber to drive an air turbine to generate electricity. To improve energy transfer efficiency, some devices employ hydraulic transmission, where a hydraulic pump converts wave mechanical energy into high-pressure hydraulic fluid, which then drives a generator via a hydraulic motor. Accumulators are installed in the pipelines to smooth out flow fluctuations. To enhance overload protection, most devices rely on external mechanical displacement sensors or acoustic / optical sea state measuring instruments to trigger protection under harsh sea conditions. To adapt to the seawater environment, some all-seawater hydraulic systems use engineering ceramic plungers and cylinder liners, as well as PEEK seals, to withstand seawater corrosion.

[0004] However, the aforementioned existing technologies have the following shortcomings: traditional mechanical generators are not sensitive to small waves, have a narrow energy capture bandwidth, and are difficult to start in relatively calm sea conditions; rigid metal blades or floats are easily damaged by typhoons and giant waves, resulting in poor survivability in extreme sea conditions; engineering ceramic plungers and cylinder liners in all-seawater hydraulic systems are prone to micro-crack propagation or even breakage under transient high-frequency rigid impacts; unidirectional hydraulic pumping systems have a "reversal dead zone," leading to a wide range of zero output power and severe ripple, requiring large energy storage components to mitigate these issues. In summary, existing wave energy power generation technologies suffer from low power generation efficiency and low stability. Summary of the Invention

[0005] This invention provides a jellyfish-inspired wave energy power generation device, power generation method, and design method, which can solve the problems of low power generation efficiency and low stability in the prior art. The technical solution is as follows: In a first aspect, a jellyfish-inspired wave energy power generation device includes: a biomimetic jellyfish umbrella, a flexible frame, a full-seawater hydraulic system, a dielectric elastomer film, and a power conversion system; The biomimetic jellyfish umbrella-shaped canopy has a radially symmetrical structure. The flexible skeleton is disposed inside the biomimetic jellyfish umbrella cover to provide support for the biomimetic jellyfish umbrella cover, and to drive the biomimetic jellyfish umbrella cover to contract under the action of waves, and to drive the biomimetic jellyfish umbrella cover to expand when the waves recede. The full-seawater hydraulic system uses the surrounding seawater as the working medium to convert the kinetic energy generated by the contraction and expansion of the biomimetic jellyfish umbrella into electrical energy. The dielectric elastomer film is bonded to the biomimetic jellyfish umbrella-shaped canopy; The power conversion system is connected to the full seawater hydraulic system and the dielectric elastomer film respectively, and is used to combine the electrical energy output by the full seawater hydraulic system and the electrical energy output by the dielectric elastomer film before outputting it.

[0006] Optionally, the biomimetic jellyfish umbrella is a load-bearing shell made of flexible polymer material and fiber-reinforced composite structure. Its overall geometry is hemispherical or approximately hemispherical, and its thickness gradually decreases from the center to the edge. The dielectric elastomer film is attached to the outer surface or between the inner and outer surfaces of the biomimetic jellyfish umbrella and adopts a three-layer composite structure. The middle layer of the three-layer composite structure is an acrylic elastomer, and the upper and lower surfaces of the middle layer are respectively coated with a flexible electrode layer composed of single-walled carbon nanotubes and polydimethylsiloxane composite conductive paste.

[0007] Optionally, the flexible skeleton includes eight radial ribs, eight return springs, and a central hub; the central hub is fixedly disposed at the center of the biomimetic jellyfish umbrella cover, the eight radial ribs are evenly spaced along the circumference of the central hub, the root of each radial rib is fixed to the central hub, and the free end extends to the edge of the biomimetic jellyfish umbrella cover and is fixed thereon; the return springs are used to drive the biomimetic jellyfish umbrella cover and the flexible skeleton to return to their original positions.

[0008] Optionally, the all-seawater hydraulic system includes a seawater plunger pump driven by the radial ribs, a suction check valve located at the inlet of the seawater plunger pump, a pressure check valve located at the outlet of the seawater plunger pump, a bladder accumulator, a seawater hydraulic motor, a high-pressure manifold, a permanent magnet synchronous generator, a filter, and a safety relief valve. The middle part of the radial ribs is connected to the piston rod of the seawater plunger pump via a hinge or ball joint. The seawater plunger pump drives the seawater hydraulic motor via the high-pressure manifold, and the seawater hydraulic motor is connected to... The permanent magnet synchronous generator is used to convert the kinetic energy generated by the contraction and expansion of the biomimetic jellyfish umbrella into electrical energy. The filter is located at the inlet of the seawater plunger pump. The inlet of the seawater plunger pump is connected to the main inlet pipe via the suction check valve. The outlet of the seawater plunger pump is connected to the high-pressure water collection main pipe via the pressure check valve. The bladder-type accumulator is connected in parallel to the high-pressure water collection main pipe and is filled with nitrogen. The safety overflow valve is connected between the high-pressure water collection main pipe and the ocean.

[0009] Optionally, the power conversion system includes a rectifier circuit, an initial bias power supply, a high-voltage electronic switch array, a DC-DC buck converter, a common DC bus, an inverter circuit, and a composite umbilical cable; the output terminal of the permanent magnet synchronous generator is connected to the common DC bus via the rectifier circuit; the dielectric elastomer film is connected to the common DC bus via the high-voltage electronic switch array and the DC-DC buck converter; the initial bias power supply provides bias charge to the dielectric elastomer film via the high-voltage electronic switch array; the common DC bus is connected to the composite umbilical cable via the inverter circuit and is connected to the power grid via the composite umbilical cable; the high-voltage electronic switch array is configured to inject a bias voltage into the dielectric elastomer film by the initial bias power supply when a wave load is input, and adjust the mechanical energy extracted by the dielectric elastomer film during the wave cycle by adjusting the amplitude of the bias voltage.

[0010] Optionally, it also includes a central controller, which calculates the real-time capacitance value and its rate of change of the dielectric elastomer film online via the high-voltage electronic switch array. The central controller is configured to: determine an overload sea state when the rate of change of the capacitance value exceeds a set threshold, and execute the following actions in conjunction: increase the voltage injected into the dielectric elastomer film via the high-voltage electronic switch array to increase the mechanical energy extracted by the dielectric elastomer film within the wave cycle, and simultaneously drive the safety overflow valve to fully open so that the seawater discharged by the seawater plunger pump is depressurized directly to the ocean without passing through the seawater hydraulic motor.

[0011] Optionally, the dielectric elastomer film and the permanent magnet synchronous generator perform spatiotemporal phase complementary current convergence at the common DC bus; during the pressurized water power generation period when the wave crest arrives and the radial ribs are pressed down, the seawater hydraulic motor drives the permanent magnet synchronous generator to output main power to the common DC bus through the rectifier circuit, and the dielectric elastomer film is stretched and charged by the initial bias power supply; during the hydraulic commutation dead zone period when the wave trough arrives or the commutation occurs, the seawater plunger pump enters water intake reset, the output of the permanent magnet synchronous generator decreases, and the dielectric elastomer film rebounds and contracts, causing its voltage to rise, and injects electrical energy into the common DC bus through the high-voltage electronic switch array and the DC-DC buck converter to fill the power gap during the hydraulic commutation dead zone period.

[0012] Optionally, the system also includes an energy management module configured to allocate power between the dielectric elastomer film and the permanent magnet synchronous generator according to real-time sea conditions: in low sea states, the dielectric elastomer film primarily generates power; in medium sea states, both output power simultaneously, with a portion of the electrical energy output by the dielectric elastomer film injected into the excitation winding of the permanent magnet synchronous generator; and in high sea states, the permanent magnet synchronous generator primarily generates power, with the electrical energy output by the dielectric elastomer film used to enhance the excitation efficiency of the permanent magnet synchronous generator.

[0013] Secondly, a jellyfish-inspired wave energy power generation method, based on the aforementioned jellyfish-inspired wave energy power generation device, includes the following steps: S1: When waves arrive, the biomimetic jellyfish umbrella captures wave energy from any direction through its radially symmetrical structure. The flexible skeleton drives the biomimetic jellyfish umbrella to contract under the action of waves. The all-seawater hydraulic system uses the surrounding seawater as the working medium to convert the kinetic energy generated by the contraction of the biomimetic jellyfish umbrella into electrical energy. At the same time, the dielectric elastomer film attached to the biomimetic jellyfish umbrella deforms synchronously with the contraction of the biomimetic jellyfish umbrella, and the mechanical energy is converted into electrical energy by the capacitance change generated by the deformation. S2: When the waves recede, the flexible skeleton drives the biomimetic jellyfish umbrella to expand. The full seawater hydraulic system converts the kinetic energy generated by the expansion of the biomimetic jellyfish umbrella into electrical energy. At the same time, the dielectric elastomer film recovers its deformation as the biomimetic jellyfish umbrella expands, and uses the capacitance change generated by the deformation to convert mechanical energy into electrical energy. S3: The power conversion system combines the electrical energy output from the full seawater hydraulic system with the electrical energy output from the dielectric elastomer film and then outputs it. S4: In the continuous wave cycle, steps S1 to S3 are executed cyclically to achieve continuous power generation.

[0014] Thirdly, a design method for a jellyfish-inspired wave energy power generation device, used to design the aforementioned jellyfish-inspired wave energy power generation device, includes the following steps: Sa: Bionic structure design steps: Taking the radially symmetrical umbrella-shaped cover of a jellyfish as the bionic prototype, the overall geometric shape of the bionic jellyfish umbrella-shaped cover is determined to be hemispherical or approximately hemispherical, with the thickness gradually decreasing from the center to the edge; the distribution of the flexible skeleton is determined, such that the eight radial ribs are evenly spaced along the circumference of the central hub, and the free ends of each radial rib extend to the edge of the bionic jellyfish umbrella-shaped cover and are fixed; the return spring causes the flexible skeleton to arch slightly upward in its natural state to store elastic potential energy, thus giving it elastic energy storage and release functions. Sb: Wave energy input boundary design steps: Determine the effective wave height based on measured sea state data of the target deployment area. With wave energy cycle The wave energy flux density is calculated using the formula for the average energy flux density per unit wave crest of irregular deep-water waves: ; In the formula, Let ρ be the average energy flux density per unit wave crest, ρ be the density of seawater, and g be the acceleration due to gravity; and determine the reference capture width B of the device and the total mechanical power of target capture. The following formula was used to verify the capture width ratio: ; When the capture width ratio exceeds the preset threshold, hydrodynamic simulation verification needs to be completed by combining the biomimetic shape of the biomimetic jellyfish umbrella, the stiffness of the radial ribs, and the wave incident angle. Sc: Hydraulic power rail parameter design steps: Determine the plunger diameter D and the maximum reciprocating stroke of the seawater plunger pump. The system's rated operating pressure difference Δp is used to match the displacement of the seawater plunger pump with the contraction stroke of the biomimetic jellyfish umbrella; the hydraulic rail output power is calculated and verified step by step according to the following hydraulic power chain closed-loop equations: ; ; ; ; ; ; ; ; In the formula, Let be the cross-sectional area of ​​the plunger. It is a single-cylinder, single-stroke displacement. Let n be the total geometric displacement of n groups of plungers in a single cycle. For theoretical flow rate, This represents the actual effective average flow rate. For plunger volumetric efficiency. The hydraulic power at the motor inlet. For the overall mechanical efficiency of hydraulic motors, This refers to the output shaft power of the hydraulic motor. This is the reference efficiency of the permanent magnet synchronous generator. The final grid-connected power of the hydraulic rail; the working pressure of the all-seawater hydraulic system should be within the range of 10-20 MPa during the design; Sd: Design steps for dielectric elastomer power generation rail parameters: Determine the relative permittivity of the dielectric elastomer film. Initial area of ​​a single thin film Initial film thickness Maximum isotropic stretch ratio Precharge bias voltage The number of parallel thin films in the whole machine (m); calculate the output power of the dielectric elastomer power generation rail according to the following set of electromechanical coupling equations: ; ; ; ; In the formula, This is the initial capacitance value of the thin film. The vacuum permittivity, This is the capacitance value when the film is stretched to its maximum. This represents the ideal energy storage difference in a single-cycle constant-voltage mode for a single thin-film membrane. For the net efficiency of the cycle, This represents the actual output power of the dielectric elastomer of the entire machine; during the design process, it should be checked that the electric field strength inside the film after stretching does not exceed the material breakdown field strength. Se: Dual-rail grid connection verification and excitation efficiency design steps: Directly add the output power of the hydraulic rail to the output power of the dielectric elastomer power generation rail, and calculate the total power and overall power transfer efficiency of the non-cooperative direct grid connection according to the following formula: ; ; In the formula, To capture the total mechanical power for the target; when the permanent magnet synchronous generator adopts an electrically excited or hybrid excited structure, a certain proportion α of the output power of the dielectric elastomer generator rail is injected into the excitation winding of the permanent magnet synchronous generator to improve the generator efficiency. The total grid-connected power after excitation efficiency enhancement is calculated according to the following formula: ; In the formula, The excitation efficiency is calculated using α, where α is the excitation allocation ratio. The excitation efficiency enhancement scheme is adopted only when the total grid-connected power after excitation enhancement is greater than the total grid-connected power without coordination. Sf: Water absorption velocity and marine ecology verification steps: Calculate the water absorption flow rate during the rebound water absorption process of the biomimetic jellyfish bell, and verify the maximum transient velocity at the filter according to the following formula: ; ; ; In the formula, The time for the water absorption process. This represents the average water absorption flow rate. This represents the peak water absorption flow rate. This refers to the total area of ​​the filter screen outer casing. For open area ratio, The clogging area coefficient should be used; during the design process, the maximum transient flow velocity should be kept below the ecological reference limit, and the minimum filter area should be determined by back-calculation based on the verification results. Sg: Energy management strategy design steps: Configure the energy management module to automatically adjust the power distribution between the dielectric elastomer film and the permanent magnet synchronous generator according to real-time sea conditions: in low sea conditions, the dielectric elastomer film generates the main power; in medium sea conditions, both output simultaneously; in high sea conditions, the permanent magnet synchronous generator generates the main power; configure the central controller to control the safety relief valve to fully open to unload hydraulic resistance in extreme sea conditions, and adjust the bias voltage injected into the dielectric elastomer film through the high-voltage electronic switch array to achieve active survival control.

[0015] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following: This invention provides a jellyfish-inspired wave energy generation device, generation method, and design method. By designing the jellyfish-inspired umbrella canopy with a radially symmetrical structure, the wave thrust can be transmitted to the internal flexible skeleton regardless of the direction of the wave, thus capturing waves from any direction without directional limitations. This overcomes the directional limitation of existing devices that require facing the incoming wave direction to work efficiently, simplifying deployment and maintenance. The flexible skeleton inside the jellyfish-inspired umbrella canopy, including radial ribs and a return spring, drives the umbrella canopy to contract under the action of waves and expand when the waves recede, ensuring reliable opening and closing of the umbrella canopy in each wave cycle and improving the continuity and reliability of wave energy capture. The all-seawater hydraulic system uses surrounding seawater as the working medium, with the radial ribs driving a seawater plunger pump, which is then driven by a suction check valve, a discharge check valve, a bladder accumulator, and a high-pressure water collection main pipe. A seawater hydraulic motor drives a permanent magnet synchronous generator to generate electricity, fundamentally eliminating the risk of marine pollution from mineral hydraulic oil leaks and achieving zero pollution and eco-friendliness. Furthermore, a bladder-type accumulator smooths out flow and pressure fluctuations, resulting in stable output. A dielectric elastomer membrane generates electricity by utilizing capacitance changes caused by the deformation of the membrane along with the biomimetic jellyfish umbrella and radial ribs. This membrane is highly sensitive to small waves, overcoming the shortcomings of traditional mechanical generators, such as difficulty in starting in calm sea conditions and a narrow energy capture bandwidth. A power conversion system connects the permanent magnet synchronous generator and the dielectric elastomer membrane, combining the two power sources for output. This combines the permanent magnet synchronous generator's sensitivity to low-frequency, high-thrust waves with the dielectric elastomer membrane's high sensitivity to small waves, achieving efficient wave energy capture and conversion across a wide sea frequency range. This effectively solves the problems of low power generation efficiency and low stability in existing technologies. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall structure provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the seawater plunger pump structure provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of a composite power conversion system provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the sea state self-sensing active survival control process provided in an embodiment of the present invention; Figure 5This is a schematic diagram of the dielectric elastomer film and its operation process provided in the embodiments of the present invention; Figure 6 This is a schematic diagram of the all-seawater hydraulic system provided in an embodiment of the present invention; Figure 7 This is a flowchart of the power generation method provided in an embodiment of the present invention.

[0018] In the diagram: 1- Bionic jellyfish umbrella; 2- Flexible skeleton; 21- Radial rib; 22- Return spring; 23- Central hub; 3- Full seawater hydraulic system; 31- Seawater plunger pump; 311- Piston rod; 312- Cylinder body; 313- Plunger; 32- Intake check valve; 33- Pressure check valve; 34- Bladder accumulator; 35- Seawater hydraulic motor; 36- High-pressure water collection manifold; 37- Permanent magnet synchronous generator; 38- Filter; 39- Safety relief valve; 30- Inlet manifold; 4- Dielectric elastomer film; 5- Power conversion system; 51- Rectifier circuit; 52- Initial bias power supply; 53- High-voltage electronic switch array; 54- DC-DC step-down converter; 55- Common DC bus; 56- Inverter circuit; 57- Composite umbilical cable; 6- Central controller; 7- Energy management module. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0020] Figure 1 This is a schematic diagram of the overall structure provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the seawater plunger pump structure provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of a composite power conversion system provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the sea state self-sensing active survival control process provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the dielectric elastomer film and its operation process provided in the embodiments of the present invention; Figure 6 This is a schematic diagram of the all-seawater hydraulic system provided in an embodiment of the present invention; Figure 7 This is a flowchart of a power generation method provided in an embodiment of the present invention. Figures 1 to 7The illustrated jellyfish-inspired wave energy power generation device includes: a biomimetic jellyfish umbrella cover 1, a flexible frame 2, a full-seawater hydraulic system 3, a dielectric elastomer film 4, and a power conversion system 5. The biomimetic jellyfish umbrella cover 1 has a radially symmetrical structure, used to capture waves from any direction without directional restrictions. The flexible frame 2 is disposed inside the biomimetic jellyfish umbrella cover 1 and includes radial ribs 21 and a return spring 22, used to drive the biomimetic jellyfish umbrella cover 1 to contract under the action of waves and to drive the biomimetic jellyfish umbrella cover 1 to expand when the waves recede. The full-seawater hydraulic system 3 uses surrounding seawater as the working medium and includes a seawater plunger pump 31 driven by the radial ribs 21 and a seawater plunger pump 31 inlet. The system includes a water inlet suction check valve 32, a water outlet pressure check valve 33, a bladder accumulator 34, and a seawater hydraulic motor 35. A seawater plunger pump 31 drives the seawater hydraulic motor 35 via a high-pressure water collection main pipe 36. The seawater hydraulic motor 35 is connected to a permanent magnet synchronous generator 37. A dielectric elastomer film 4 is attached to the biomimetic jellyfish umbrella cover 1. The film generates electricity by utilizing the capacitance change caused by the deformation of the dielectric elastomer film 4 with the biomimetic jellyfish umbrella cover 1 and radial ribs 21. A power conversion system 5 is connected to the permanent magnet synchronous generator 37 and the dielectric elastomer film 4 respectively. The system is used to combine the electrical energy output by the permanent magnet synchronous generator 37 and the electrical energy output by the dielectric elastomer film 4 before outputting the combined power.

[0021] In an exemplary embodiment of the invention, the edge of the biomimetic jellyfish umbrella cover 1 is fixedly connected to the free end of the radial rib 21 of the flexible skeleton 2. The middle part of the radial rib 21 is drivenly connected to the piston rod of the seawater plunger pump 31. The inlet of the seawater plunger pump 31 is connected to seawater via a suction check valve 32, and the outlet is connected to the high-pressure water collection manifold 36 via a pressure check valve 33. The output end of the high-pressure water collection manifold 36 is connected to the seawater hydraulic motor 35. The output shaft of the seawater hydraulic motor 35 is drivenly connected to the input shaft of the permanent magnet synchronous generator 37. The bladder-type accumulator 34 is connected in parallel to the high-pressure water collection manifold 36. The dielectric elastomer film 4 is connected to the power conversion system 5 via wires. The output end of the permanent magnet synchronous generator 37 is also connected to the power conversion system 5. The outer surface of the dielectric elastomer film 4 is also densely wrapped with a flexible open waterproof insulating encapsulation layer, such as fluorosilicone rubber or a superhydrophobic polyurethane layer. When a wave surges in, at its crest, the kinetic energy of the wave impacts the biomimetic jellyfish bell 1, forcing it to contract inward along a radially symmetrical direction. Because the biomimetic jellyfish bell 1 has a radially symmetrical structure, it can transfer the wave's thrust to the internal flexible skeleton 2 regardless of the wave's direction, thus achieving wave capture without directional limitations. The contraction of the biomimetic jellyfish bell 1 causes the radial ribs 21 to bend and deform inward, which in turn drives the piston rod of the seawater plunger pump 31 to press into the bottom of the cylinder. As the working chamber volume of the seawater plunger pump 31 decreases, the seawater pressure inside the chamber rises sharply. The high-pressure seawater forces the suction check valve 32 to close in the reverse direction and simultaneously opens the discharge check valve 33, flowing into the high-pressure water collection main pipe 36 in a pulsed manner. The bladder-type accumulator 34 absorbs and smooths the flow pulsation in the high-pressure water collection main pipe 36, making the seawater flow output to the seawater hydraulic motor 35 more stable. The stable high-pressure seawater drives the seawater hydraulic motor 35 to rotate and do work. The seawater hydraulic motor 35 drives the permanent magnet synchronous generator through its output shaft. As the rotor of generator 37 rotates, the permanent magnet synchronous generator 37 cuts magnetic field lines to generate alternating current. Simultaneously, the deformation of the biomimetic jellyfish umbrella 1 and radial ribs 21 causes the dielectric elastomer film 4 attached to it to be stretched and thinned synchronously. The film area increases and the thickness decreases, and the capacitance value of the dielectric elastomer film 4 changes significantly. The dielectric elastomer film 4 uses this capacitance change to convert mechanical energy into electrical energy. When the wave recedes, i.e., at the trough, the reset spring 22 in the flexible skeleton 2 releases elastic potential energy, driving the radial ribs 21 to rebound outward, thereby causing the biomimetic jellyfish umbrella 1 to expand again and return to the initial capture posture. At the same time, the piston rod of the seawater plunger pump 31 retracts outward, and a negative pressure is formed in the working chamber. The external seawater is re-inhaled into the cylinder through the suction check valve 32, completing a suction reset stroke and accumulating power for the high-pressure drainage of the next cycle. The power conversion system 5 receives the electrical energy output from the permanent magnet synchronous generator 37 and the electrical energy output from the dielectric elastomer film 4, and combines the two electrical energy streams for unified output.Therefore, this device combines two power generation modes: 37 pairs of permanent magnet synchronous generators sensitive to low-frequency high-thrust waves and 4 pairs of dielectric elastomer films highly sensitive to micro waves. This enables efficient capture and conversion of wave energy under wide-band sea conditions, effectively solving the problems of low power generation efficiency and low stability in existing technologies.

[0022] Optionally, the biomimetic jellyfish umbrella cover 1 is a load-bearing shell made of flexible polymer material and fiber-reinforced composite structure. Its overall geometry is hemispherical or approximately hemispherical, and its thickness gradually decreases from the center to the edge. The dielectric elastomer film 4 is attached to the outer surface or between the inner and outer surfaces of the biomimetic jellyfish umbrella cover 1 and adopts a three-layer composite structure. The middle layer of the three-layer composite structure is an acrylic elastomer, and the upper and lower surfaces of the middle layer are respectively coated with a flexible electrode layer composed of single-walled carbon nanotubes and polydimethylsiloxane composite conductive paste.

[0023] For example, in this embodiment of the invention, the biomimetic jellyfish umbrella cover 1 serves as a load-bearing outer shell. Its hemispherical or near-hemispherical geometry has a larger thickness in the central region and a smaller thickness in the edge region. The dielectric elastomer film 4 is attached to the outer surface of the biomimetic jellyfish umbrella cover 1 or sandwiched between its inner and outer surfaces in the form of a three-layer composite structure. The upper and lower surfaces of the acrylate elastomer, which serves as the middle layer in the three-layer composite structure, are respectively attached to two flexible electrode layers. The flexible electrode layers are led out through wires and connected to the power conversion system 5. Under wave load, the wave force first acts on the edge region of the biomimetic jellyfish umbrella 1. Since the thickness of the biomimetic jellyfish umbrella 1 gradually decreases from the center to the edge, the edge region has lower stiffness and the center region has higher stiffness, thus simulating the variable stiffness characteristics of the jellyfish umbrella. This allows the wave force to be concentrated and transmitted along the path of gradually increasing stiffness from the edge to the center. The flexible polymer material and fiber-reinforced composite structure not only ensure the overall load-bearing strength of the umbrella, but also give it the flexibility required for bending with the waves. When the biomimetic jellyfish umbrella 1 shrinks or expands, the three-layer composite structure simultaneously undergoes in-plane stretching or rebound. The acrylate elastomer, as the middle layer, becomes thinner as the area increases, and the spacing between the upper and lower flexible electrode layers changes accordingly. The flexible electrode layer, composed of single-walled carbon nanotubes and polydimethylsiloxane composite conductive paste, can maintain conductive continuity without cracking during the large deformation of the film. This reliably converts the geometric deformation of the film into capacitance changes between the two electrode layers, and outputs the capacitance to the power conversion system 5 via wires. Thus, this structure enables the dielectric elastomer film 4 to possess excellent load-bearing capacity, flexibility, and efficient electromechanical conversion capabilities, thereby improving deformation and power generation sensitivity under low sea conditions.

[0024] Optionally, the flexible frame 2 includes a central hub 23, eight radial ribs 21, and eight return springs 22; the root of each radial rib 21 is fixed to the central hub 23, and the free end extends to the edge of the biomimetic jellyfish umbrella 1 and is fixed thereon; the cross-section of the radial rib 21 is I-shaped or C-shaped; the middle of each radial rib 21 is connected to the piston rod 311 of the seawater plunger pump 31 via a hinge or ball joint; the seawater plunger pump 31 is a ceramic single-acting cylinder, the cylinder body 312 and the plunger 313 of the ceramic single-acting cylinder are made of engineering ceramic material, which is alumina ceramic or pressureless sintered silicon carbide, and the surface of the piston rod 311 is covered with a polyetheretherketone wear-resistant layer; the return spring 22 is located in the ceramic single-acting cylinder, which is used to drive the piston rod 311 to return to its original position, and also serves as an elastic energy storage element for the expansion of the biomimetic jellyfish umbrella 1.

[0025] For example, in this embodiment of the invention, eight radial ribs 21 are evenly distributed radially around the central hub 23. The root of each radial rib 21 is fixed to the central hub 23, and the free end is fixed to the edge of the biomimetic jellyfish umbrella cover 1. The middle part of each radial rib 21 is hinged to the piston rod 311 of a seawater plunger pump 31 via a hinge or ball joint. The eight seawater plunger pumps 31, i.e. ceramic single-acting cylinders, are evenly distributed in a ring. The return spring 22 is located inside the ceramic single-acting cylinder and abuts against the piston rod 311. When the wave crest arrives and the biomimetic jellyfish umbrella 1 contracts inward under the pressure of the wave, the eight radial ribs 21 simultaneously bend inward. The I-shaped or C-shaped cross-section of the radial ribs 21 provides high bending stiffness while maintaining necessary axial elasticity, enabling them to reliably withstand wave impact without brittle fracture. The radial ribs 21 are connected to their corresponding piston rods 311 via hinges or ball joints. The hinges or ball joints allow for angle changes during the bending process of the radial ribs 21, preventing the piston rods 311 from being subjected to lateral loads. The piston rods 311 push the plunger 313 to move linearly towards the bottom of the cylinder within the cylinder body 312. The cylinder is made of alumina ceramic. The cylinder 312 and plunger 313, made of engineering ceramic materials such as pressureless sintered silicon carbide, possess high hardness and resistance to seawater corrosion. The polyetheretherketone wear-resistant layer on the surface of the piston rod 311 achieves low-friction reciprocating motion in seawater, while the compression return spring 22 stores elastic potential energy. When the wave trough arrives and the wave pressure disappears, the compressed return spring 22 releases its elastic potential energy, pushing the piston rod 311 and plunger 313 to return to their original position, allowing the ceramic single-acting cylinder to complete the water intake and return stroke. On the other hand, it drives the biomimetic jellyfish umbrella 1 to actively expand outward via the radial ribs 21, restoring its initial posture. Since the return spring 22 simultaneously performs the functions of piston return and umbrella expansion energy storage, this structure simplifies the mechanism while ensuring reliable opening and closing of the umbrella in each wave cycle, improving the continuity and reliability of wave energy capture.

[0026] Optionally, the all-seawater hydraulic system 3 also includes a filter 38 and a safety relief valve 39; the filter 38 is located at the inlet of the seawater plunger pump 31; the inlet of the seawater plunger pump 31 is connected to the inlet manifold 30 via a suction check valve 32, and the outlet of the seawater plunger pump 31 is connected to the high-pressure manifold 36 via a pressure check valve 33; a bladder-type accumulator 34 is connected in parallel to the high-pressure manifold 36 and is filled with nitrogen; the safety relief valve 39 is connected between the high-pressure manifold 36 and the ocean; the working pressure of the all-seawater hydraulic system 3 is 10-20 MPa.

[0027] For example, in this embodiment of the invention, the filter 38 can be a titanium alloy filter screen. The filter 38 is disposed at the inlet of the seawater plunger pump 31 and located between the inlet main pipe 30 and the suction check valve 32. The inlet of the seawater plunger pump 31 is connected to the inlet main pipe 30 via the suction check valve 32, and the outlet is connected to the high-pressure water collection main pipe 36 via the pressure check valve 33. The bladder-type accumulator 34 is connected in parallel to the high-pressure water collection main pipe 36 and is filled with nitrogen. One end of the safety overflow valve 39 is connected to the high-pressure water collection main pipe 36, and the other end is connected to the ocean. During the water intake and reset phase, a negative pressure is created in the working chamber of the seawater plunger pump 31. External seawater first passes through filter 38 to remove impurities such as barnacles and algae debris before entering the main inlet pipe 30. Then, it opens the suction check valve 32 and enters the working chamber. The seawater corrosion resistance of filter 38 ensures long-term reliable filtration in open seawater environments, preventing particulate matter from entering the ceramic friction pair and causing wear or jamming. During the water discharge phase, the seawater pressure in the working chamber rises to the system working pressure, i.e., the range of 10–20 MPa. The high-pressure seawater opens the pressure check valve 33 and discharges into the high-pressure water collection main pipe 36. At this time, the suction check valve 32 is reverse-pressure closed to prevent the high-pressure seawater from entering the working chamber. Backflow is directed to the inlet side; due to the asynchronous drainage of water by the eight seawater plunger pumps 31 with the wave phase difference, the flow rate in the high-pressure manifold 36 is pulsating. The parallel bladder accumulator 34 is compressed by the high-pressure seawater at the peak flow to absorb and store energy in its internal nitrogen bladder. During the pumping interval, the nitrogen bladder rebounds and releases the stored energy at a stable flow rate, thereby smoothing out the flow and pressure pulsations. When encountering extreme sea conditions and the pressure in the high-pressure manifold 36 exceeds the system's set threshold, the safety relief valve 39 automatically opens, allowing the high-pressure seawater to be depressurized directly to the ocean without passing through the seawater hydraulic motor 35, thus providing overload protection for the all-seawater hydraulic system 3. Therefore, the cooperation of the filter 38, the bladder accumulator 34, and the safety relief valve 39 not only ensures the clean operation and stable output of the system in the seawater environment, but also gives the system the ability to safely unload under high-pressure impact.

[0028] Optionally, the power conversion system 5 includes a rectifier circuit 51, an initial bias power supply 52, a high-voltage electronic switch array 53, a DC-DC step-down converter 54, a common DC bus 55, an inverter circuit 56, and a composite umbilical cable 57; the output terminal of the permanent magnet synchronous generator 37 is connected to the common DC bus 55 via the rectifier circuit 51; the dielectric elastomer film 4 is connected to the common DC bus 55 via the high-voltage electronic switch array 53 and the DC-DC step-down converter 54; the initial bias power supply 52 provides bias charge to the dielectric elastomer film 4 via the high-voltage electronic switch array 53; the common DC bus 55 is connected to the composite umbilical cable 57 via the inverter circuit 56, and is connected to the power grid via the composite umbilical cable 57.

[0029] For example, in this embodiment of the invention, the three-phase AC output terminal of the permanent magnet synchronous generator 37 is connected to the input terminal of the rectifier circuit 51, and the output terminal of the rectifier circuit 51 is connected to the common DC bus 55; the dielectric elastomer film 4 is connected to the input terminal of the DC-DC buck converter 54 via the high-voltage electronic switch array 53, and the output terminal of the DC-DC buck converter 54 is connected to the common DC bus 55; the initial bias power supply 52 is connected to the dielectric elastomer film 4 via the high-voltage electronic switch array 53; the output terminal of the common DC bus 55 is connected to the input terminal of the inverter circuit 56, and the output terminal of the inverter circuit 56 is led to the power grid via the composite umbilical cable 57. In the hydraulic main power generation branch, the permanent magnet synchronous generator 37 generates three-phase alternating current with voltage and frequency fluctuating with sea conditions as the seawater hydraulic motor 35 rotates. This alternating current is modulated into direct current by the rectifier circuit 51 and then directly transmitted to the common DC bus 55. In the dielectric elastomer power generation branch, when the radial rib 21 is driven by waves to bend to its maximum extension state, the dielectric elastomer film 4 is stretched to its maximum area and minimum thickness, and its capacitance reaches its maximum value. At this time, the charging switch in the high-voltage electronic switch array 53 is turned on, and the initial charge is injected into the dielectric elastomer film 4 by the initial bias power supply 52. ​​When the waves recede and the radial rib 21 rebounds, the dielectric elastomer film 4 contracts, reducing its area and increasing its thickness. When the capacitance drops to its minimum value, and the charging switch is off, the locked charge causes the voltage across the thin film to rise sharply to the kilovolt level according to the principle of charge conservation, thus converting mechanical energy into high-voltage electrostatic energy. Subsequently, the discharge switch in the high-voltage electronic switch array 53 is turned on, and the high-voltage electrostatic energy flows through the DC-DC step-down converter 54, is stepped down to low-voltage DC, and then sent to the common DC bus 55. At the node of the common DC bus 55, the DC power from the hydraulic main power generation branch and the dielectric elastomer power generation branch is superimposed, and the merged DC power is uniformly input into the inverter circuit 56, modulated into constant-frequency and constant-voltage AC power conforming to the grid specifications, and finally connected to the grid through the transmission conductor in the composite umbilical cable 57. Thus, the power conversion system 5 realizes the unified convergence and standardized grid-connected output of two heterogeneous power sources on the DC bus side.

[0030] Optionally, the high-voltage electronic switch array 53 is configured to inject a bias voltage into the dielectric elastomer film 4 by the initial bias power supply 52 when a wave load is input, and to adjust the mechanical energy extracted by the dielectric elastomer film 4 during the wave cycle by adjusting the amplitude of the bias voltage.

[0031] For example, in this embodiment of the invention, the input terminal of the high-voltage electronic switch array 53 is connected to the initial bias power supply 52, and the output terminal is connected to the dielectric elastomer film 4, and it has the function of adjusting the amplitude of the applied bias voltage. Its working principle and process are as follows: When a wave load is input and the radial rib 21 is forced to bend, causing the dielectric elastomer film 4 to be stretched, the high-voltage electronic switch array 53 injects a bias voltage into the dielectric elastomer film 4 from the initial bias power supply 52. ​​Under the action of this bias electric field, the dielectric elastomer film 4 generates Maxwell stress, which compresses along the thickness direction and contracts along the stretching direction. The physical expression of this Maxwell stress is: ; In the formula, For Maxwell stress, The relative permittivity of the dielectric elastomer film 4 is given by [insert value here]. Let E(t) be the vacuum permittivity, and E(t) be the real-time electric field intensity inside the thin film. λ(t) represents the real-time injected bias voltage, and λ(t) represents the real-time stretching ratio of the thin film. This represents the initial thickness of the film. Mechanically, this Maxwell stress manifests as an elastic damping force that counteracts the further bending and stretching of the radial rib 21; from the above equation, it can be seen that the Maxwell stress... With bias voltage It is proportional to the square of the value, therefore, by adjusting the bias voltage... The amplitude of the change can alter the magnitude of the elastic damping force, thereby changing the resistance of the dielectric elastomer film 4 to the bending deformation of the radial rib 21, thus adjusting the amount of mechanical energy absorbed and converted by the dielectric elastomer film 4 during each wave cycle. Furthermore, within the extremely short time window of the transient strong wave inrush, typically 0.1s to 0.5s of the rising edge of the wave front, the dielectric elastomer film 4 absorbs and converts most of the high-frequency, high-acceleration mechanical kinetic energy from the outside through the electric field force, smoothing out the peaks and valleys of the mechanical load curve input to the lower seawater plunger pump 31, converting the steep rigid impact into a gentle thrust, thereby preventing the cylinder 312 and plunger 313 made of engineering ceramic material from stress concentration caused by high-frequency rigid impact, which could lead to the propagation of microcracks or even breakage, and also preventing the polyether ether ketone wear-resistant layer on the surface of the piston rod 311 from tearing and failing. Therefore, the amount of mechanical energy extracted by the dielectric elastomer film 4 can be actively controlled by electrical means, so that the device can not only flexibly match the energy capture intensity according to the sea conditions, but also act as a nonlinear electronically controlled damper to protect the seawater plunger pump 31, significantly improving the system's operating life in the entire seawater environment.

[0032] Optionally, it also includes a central controller 6; the central controller 6 calculates the real-time capacitance value and its rate of change of the dielectric elastomer film 4 online via the high-voltage electronic switch array 53, so that the dielectric elastomer film 4 also serves as a variable capacitance sensor for sea state self-sensing; the central controller 6 is configured to: when the rate of change of the capacitance value exceeds a set threshold, determine that it is an overload sea state, and link to execute: increase the voltage injected into the dielectric elastomer film 4 via the high-voltage electronic switch array 53 to increase the mechanical energy extracted by the dielectric elastomer film 4 within the wave cycle; at the same time, drive the safety overflow valve 39 to fully open, so that the seawater discharged by the seawater plunger pump 31 is depressurized directly to the ocean without passing through the seawater hydraulic motor 35.

[0033] For example, in this embodiment of the invention, the central controller 6 is electrically connected to the dielectric elastomer film 4 via the current / voltage sampling module in the high-voltage electronic switch array 53, and is also connected to the control terminal signal of the safety overflow valve 39. Its working principle and process are as follows: During device operation, the central controller 6 collects the voltage and current across the dielectric elastomer film 4 in real time via the high-voltage electronic switch array 53, and then calculates the real-time capacitance value and its first-order rate of change of the dielectric elastomer film 4. Since the dielectric elastomer film 4 is an electroactive polymer, when it is deformed by wave drive, the change in its geometric dimensions leads to a high-precision monotonic mapping change in its capacitance value. The physical expression for this capacitance value is: ; In the formula, C(t) is the real-time capacitance value of the thin film. The relative permittivity of the material is Let be the vacuum permittivity, A(t) be the real-time effective area of ​​the thin film, and d(t) be the real-time thickness of the thin film. This represents the initial effective area of ​​the thin film. Let λ be the initial thickness of the film, and λ(t) be the real-time stretching ratio of the film. The initial capacitance value of the thin film is given. From the above formula, it can be seen that the capacitance value C(t) of the dielectric elastomer thin film 4 is proportional to the fourth power of its stretch ratio λ(t), meaning there is a high-precision monotonic mapping relationship between the film deformation and its capacitance value. Therefore, the dielectric elastomer thin film 4 also functions as a variable capacitance sensor for sea state self-sensing, without requiring any external mechanical displacement sensors or acoustic / optical sea state measuring instruments. Under normal sea conditions, the capacitance change rate is lower than the set threshold, the central controller 6 does not trigger protection, and the device generates electricity normally. When encountering extreme sea conditions such as typhoons, giant waves cause the radial ribs 21 to deform violently, causing the capacitance change rate to exceed the set threshold in a very short time. Based on this, the central controller 6 directly determines that the current sea state is overloaded and performs dual defense actions: firstly... First, the central controller 6 instructs the high-voltage electronic switch array 53 to increase the voltage injected into the dielectric elastomer film 4 to the maximum safe limit, causing the Maxwell stress generated to reach its extreme value. This electrically locks the free bending of the radial ribs 21, instantly increasing their stiffness and putting them into a forced wave-resistant state. Simultaneously, it increases the mechanical energy extracted by the dielectric elastomer film 4 within the wave cycle. Second, the central controller 6 outputs an electrical control signal to fully open the safety relief valve 39, preventing the high-pressure seawater discharged by the seawater plunger pump 31 from entering the seawater hydraulic motor 35 and instead releasing it directly to zero pressure in the ocean. The entire system's hydraulic circuit instantly releases pressure and loses its rigid support, allowing the device to submerge or completely unload under its own gravity and wave-following mechanism. Thus, this device utilizes the self-sensing capacitance characteristics of the dielectric elastomer film 4 to achieve active survival control without external sensors, avoiding the failure of external sensors due to salt spray corrosion and marine organism attachment, and improving the device's survivability and maintenance-free operation under extreme sea conditions.

[0034] Optionally, the dielectric elastomer film 4 and the permanent magnet synchronous generator 37 perform spatiotemporal phase complementary current convergence at the common DC bus 55; during the pressurized water power generation period when the wave crest arrives and the radial ribs 21 are pressed down, the seawater hydraulic motor 35 drives the permanent magnet synchronous generator 37 to output main power to the common DC bus 55 through the rectifier circuit 51, and the dielectric elastomer film 4 is stretched and charged by the initial bias power supply 52; during the hydraulic commutation dead zone period when the wave trough arrives or the commutation occurs, the seawater plunger pump 31 enters water suction reset, the output of the permanent magnet synchronous generator 37 decreases, and the dielectric elastomer film 4 rebounds and contracts, causing its voltage to rise. Electrical energy is injected into the common DC bus 55 through the high-voltage electronic switch array 53 and the DC-DC step-down converter 54 to fill the power gap during the hydraulic commutation dead zone period.

[0035] Exemplarily, in this embodiment of the invention, the dielectric elastomer film 4, via the high-voltage electronic switch array 53, the DC-DC step-down converter 54, and the permanent magnet synchronous generator 37, via the rectifier circuit 51, are all connected to the same common DC bus 55. The two achieve spatiotemporal phase complementarity and convergence at the common DC bus 55. This convergence process is divided into two periods according to the wave cycle. The first period is the pressurized water power generation period. When the wave crest arrives and the radial ribs 21 are pressed down, the eight seawater plunger pumps 31 are in the drainage stroke. High-pressure seawater converges to the high-pressure water collection main pipe 36, driving the seawater hydraulic motor 35. The seawater hydraulic motor 35 drives the permanent magnet synchronous generator 37 to generate power at full capacity. The permanent magnet synchronous generator 37 outputs main power to the common DC bus 55 via the rectifier circuit 51. At the same time, the dielectric elastomer film 4 is synchronously stretched to its maximum area and minimum thickness, according to the capacitance formula... At this point, the film stretching ratio λ(t) is at its maximum, and its capacitance reaches its maximum value. When the charging switch in the high-voltage electronic switch array 53 is turned on, an initial charge is injected into the dielectric elastomer film 4 by the initial bias power supply 52. During this stage, the hydraulic power generation track provides the main power output. The second period is the hydraulic reversing dead zone. When the trough arrives or at the moment of reversal, the seawater plunger pump 31 enters the suction and reset stroke. Due to the one-way valve's shut-off action, it cannot pump high-pressure seawater into the high-pressure manifold 36. The instantaneous mechanical input power of the seawater hydraulic motor 35 and the permanent magnet synchronous generator 37 drops sharply, and the output decreases accordingly, forming the hydraulic reversing dead zone. At this very moment, the originally stretched dielectric elastomer film 4 begins to rebound and shrink under the restoring force of the radial ribs 21 and the reset spring 22. Its area decreases and its thickness increases. According to the aforementioned capacitance formula, the decrease in the stretching ratio λ(t) causes the film capacitance to drop to its minimum value. Since the charging switch has been turned off at this time, the injected charge Locked to the surface of the thin film, according to the principle of charge conservation and electrical formulas As the capacitance C decreases sharply, the voltage across the thin film passively and rapidly increases to the kilovolt level, directly converting the mechanical energy of the radial ribs 21's rebound into high-voltage electrostatic energy. Upon detecting this high-voltage signal, the high-voltage electronic switch array 53 quickly conducts, precisely injecting the high-voltage electrical energy stored in the dielectric elastomer film 4 into the common DC bus 55 after being stepped down by the DC-DC buck converter 54, thus filling the power gap during the hydraulic commutation dead zone. Because the peak discharge time window of the dielectric elastomer power generation track precisely coincides with the commutation dead zone of the hydraulic power generation track on the time axis, the two power generation tracks achieve seamless energy complementarity at the common DC bus 55, naturally smoothing the ripple of the total output power and significantly reducing the capacity requirements for downstream supercapacitors or batteries.

[0036] Optionally, it also includes an energy management module 7, which is configured to adjust the power distribution between the dielectric elastomer film 4 and the permanent magnet synchronous generator 37 according to the real-time sea state: in low sea states, the dielectric elastomer film 4 generates the main power; in medium sea states, both output power simultaneously, and a portion of the electrical energy output by the dielectric elastomer film 4 is injected into the excitation winding of the permanent magnet synchronous generator 37; in high sea states, the permanent magnet synchronous generator 37 generates the main power, and the electrical energy output by the dielectric elastomer film 4 is used to enhance the excitation efficiency of the permanent magnet synchronous generator 37.

[0037] Exemplarily, in this embodiment of the invention, the energy management module 7 is connected to the dielectric elastomer film 4 and the permanent magnet synchronous generator 37, respectively, and receives signals reflecting real-time sea conditions to perform power distribution. Its working principle and process are as follows: the energy management module 7 switches between three working states according to the real-time sea conditions. The low sea state, medium sea state, and high sea state in this invention are determined by the geometric characteristics of the biomimetic umbrella canopy of this device (…). The specific numerical range for dimensionless mapping based on the following: Low sea state is defined as significant wave height. (correspond This range is mainly characterized by micro-deformation capacitor power generation performed by dielectric elastomer films; the sea state is defined as the significant wave height. (correspond In this section, the main power generation is performed by a full-seawater hydraulic plunger pump; high sea state is defined as significant wave height. (correspond This interval triggers overload overflow and flexible wave-following unloading protection for the entire system. In low sea states, the wave thrust is small, and the seawater plunger pump 31 cannot build enough pressure to drive the permanent magnet synchronous generator 37 to generate electricity efficiently. However, the dielectric elastomer film 4 is highly sensitive to small waves and can generate a significant voltage rise under small deformation. Therefore, in this state, the dielectric elastomer film 4 mainly generates electricity to compensate for the inability of traditional generators to start in stable sea states. In medium sea states, both the hydraulic power generation rail and the dielectric elastomer power generation rail have power generation capabilities and output simultaneously. The energy management module 7 injects part of the electrical energy output by the dielectric elastomer film 4 into the excitation winding of the permanent magnet synchronous generator 37 while converging the current to improve the power generation efficiency of the permanent magnet synchronous generator 37. In high sea states, the wave energy is abundant, and the hydraulic power generation rail can output high power. Therefore, the permanent magnet synchronous generator 37 mainly generates electricity, and all the electrical energy output by the dielectric elastomer film 4 is used for excitation efficiency enhancement of the permanent magnet synchronous generator 37. Therefore, the energy management module 7 dynamically allocates power weights and performs time-series coupling on the two power generation tracks according to sea conditions, achieving seamless connection and complementarity under low, medium, and high sea conditions, thus maintaining efficient power generation under all frequency band sea conditions.

[0038] A jellyfish-inspired wave energy power generation method, based on the aforementioned jellyfish-inspired wave energy power generation device, includes the following steps: S1: When waves arrive, the bionic jellyfish umbrella 1 captures wave energy from any direction through its radially symmetrical structure. The flexible skeleton 2 causes the bionic jellyfish umbrella 1 to contract under the action of waves. The all-seawater hydraulic system 3 uses the surrounding seawater as the working medium to convert the kinetic energy generated by the contraction of the bionic jellyfish umbrella 1 into electrical energy. At the same time, the dielectric elastomer film 4 attached to the bionic jellyfish umbrella 1 deforms synchronously with the contraction of the bionic jellyfish umbrella 1, utilizing the capacitance generated by the deformation. The change converts mechanical energy into electrical energy; S2: When the wave recedes, the flexible skeleton 2 drives the biomimetic jellyfish umbrella 1 to expand, and the full seawater hydraulic system 3 converts the kinetic energy generated by the expansion of the biomimetic jellyfish umbrella 1 into electrical energy. At the same time, the dielectric elastomer film 4 recovers its deformation as the biomimetic jellyfish umbrella 1 expands, and uses the capacitance change generated by the deformation to convert mechanical energy into electrical energy; S3: The power conversion system 5 combines the electrical energy output from the full seawater hydraulic system 3 and the electrical energy output from the dielectric elastomer film 4 and outputs it; S4: In the continuous wave cycle, steps S1 to S3 are executed cyclically to achieve continuous power generation.

[0039] Step S1 involves wave energy capture and dual-track power generation during wave crest. When the wave arrives at its crest, the kinetic energy of the wave impacts the biomimetic jellyfish umbrella 1. Due to the radially symmetrical structure of the biomimetic jellyfish umbrella 1, the wave's thrust can be transmitted to the internal flexible skeleton 2 regardless of the direction from which the wave originates, thus achieving wave capture without directional limitations. Under the wave's thrust, the biomimetic jellyfish umbrella 1 contracts inward along the radially symmetrical direction. Simultaneously, the eight radial ribs 21 in the flexible skeleton 2 bend and deform inward. The radial ribs 21 then drive the piston rod 311 of the seawater plunger pump 31 to press into the bottom of the cylinder. The working chamber volume of the seawater plunger pump 31 decreases, and the seawater pressure inside the chamber rises sharply. The high-pressure seawater forces the suction check valve 32 to close in the reverse direction and simultaneously opens the discharge check valve 33, pulsating into the high-pressure water collection main pipe 36. Eight seawater plunger pumps 31 alternately discharge water in sync with the wave phase difference. A bladder-type accumulator 34 absorbs and smooths the flow pulsations within the high-pressure water manifold 36. The nitrogen gas inside is compressed by the high-pressure seawater at peak flow rates to store energy. During pumping intervals, the nitrogen bladder rebounds, releasing the stored energy at a steady flow rate, thus stabilizing the seawater flow to the seawater hydraulic motor 35. The stable high-pressure seawater drives the seawater hydraulic motor 35 to rotate and perform work. The seawater hydraulic motor 35, through its output shaft, drives the rotor of a permanent magnet synchronous generator 37 to rotate. The permanent magnet synchronous generator 37 cuts magnetic field lines to generate alternating current, completing the power generation process of the hydraulic power generation track.

[0040] Simultaneously, the deformation of the biomimetic jellyfish umbrella-shaped cover 1 and radial ribs 21 causes the dielectric elastomer film 4 attached to them to be stretched and thinned, increasing the film area and reducing its thickness. The dielectric elastomer film 4 adopts a three-layer composite structure, with an acrylate elastomer as the middle layer. The upper and lower surfaces of the middle layer are coated with flexible electrode layers composed of a composite conductive paste of single-walled carbon nanotubes and polydimethylsiloxane. The flexible electrode layers maintain conductive continuity without cracking during the large deformation of the film. When the radial ribs 21 are bent to their maximum extension state by wave drive, the dielectric elastomer film 4 is stretched to its maximum area and minimum thickness. According to the capacitance formula, the film stretch ratio is at its maximum at this time, and its capacitance reaches its maximum value. The charging switch of the high-voltage electronic switch array 53 in the power conversion system 5 is turned on, and the initial charge is injected into the dielectric elastomer film 4 by the initial bias power supply 52. ​​During this stage, the hydraulic power generation rail undertakes the main power output, and the dielectric elastomer film 4 is in a charging and energy storage state.

[0041] During this process, the dielectric elastomer film 4 generates Maxwell stress under the action of a bias electric field, which compresses along the thickness direction and contracts along the stretch direction. Mechanically, this Maxwell stress manifests as an elastic damping force that resists the further bending and stretching of the radial ribs 21. The magnitude of this elastic damping force can be changed by adjusting the amplitude of the bias voltage. Thus, within a very short time window of transient strong wave inrush (usually 0.1s to 0.5s of the rising edge of the wavefront), the dielectric elastomer film 4 absorbs and converts most of the high-frequency high-acceleration mechanical kinetic energy from the outside through the electric field force, and performs peak-shaving and valley-level buffering on the mechanical load curve input to the seawater plunger pump 31. This transforms the steep rigid impact into a gentle thrust, thereby preventing the cylinder 312 and plunger 313 made of engineering ceramic material from stress concentration caused by high-frequency rigid impact, which could lead to the propagation of microcracks or even breakage. It also prevents the polyether ether ketone wear-resistant layer on the surface of the piston rod 311 from tearing and failing.

[0042] Step S2 is the elastic reset and complementary power generation step when the wave recedes, i.e., during the trough period. The reset spring 22 in the flexible frame 2 releases elastic potential energy, driving the radial ribs 21 to rebound outward, thereby causing the biomimetic jellyfish umbrella 1 to expand again and return to the initial capture posture. At the same time as the biomimetic jellyfish umbrella 1 expands, the piston rod 311 of the seawater plunger pump 31 retracts outward, creating a negative pressure in the working chamber. The external seawater first passes through the filter 38 to remove impurities such as barnacles and algae debris before entering the main inlet pipe 30, and then opens the suction check valve 32 to enter the working chamber, completing one suction reset stroke and accumulating power for the high-pressure drainage in the next cycle.

[0043] At this time, the full-seawater hydraulic system 3 is in the hydraulic reversing dead zone. The seawater plunger pump 31, due to the check valve's shut-off action, cannot pump high-pressure seawater into the high-pressure manifold 36. The instantaneous mechanical input power of the seawater hydraulic motor 35 and the permanent magnet synchronous generator 37 drops sharply, and the output decreases accordingly. However, the originally stretched dielectric elastomer film 4 begins to rebound and shrink under the restoring force of the radial ribs 21 and the return spring 22, reducing its area and increasing its thickness. According to the capacitance formula, the reduced stretching ratio causes the film capacitance to drop to its minimum value. Since the charging switch is now off, the injected initial charge is locked on the film surface. According to the principle of charge conservation and electrical formulas... As the capacitance decreases sharply, the voltage across the thin film passively and rapidly increases to the kilovolt level, directly converting the mechanical energy of the radial ribs 21's rebound into high-voltage electrostatic energy. Upon detecting this high-voltage signal, the high-voltage electronic switch array 53 quickly conducts, precisely injecting the high-voltage electrical energy stored in the dielectric elastomer film 4 into the common DC bus 55 after being stepped down by the DC-DC buck converter 54, thus filling the power gap during the hydraulic commutation dead zone. Consequently, the peak discharge time window of the dielectric elastomer power generation track precisely coincides with the commutation dead zone of the hydraulic power generation track on the time axis, achieving spatiotemporal phase complementarity between the two power generation tracks.

[0044] Step S3 is the dual-track power convergence and output step. The power conversion system 5 converges the electrical energy output from the full-seawater hydraulic system 3 and the electrical energy output from the dielectric elastomer film 4 at the common DC bus 55. In the hydraulic main power generation branch, the three-phase AC power generated by the permanent magnet synchronous generator 37, whose voltage and frequency fluctuate with the sea state, is modulated into DC power by the rectifier circuit 51 and then sent to the common DC bus 55. In the dielectric elastomer power generation branch, the high-voltage electrostatic power of the dielectric elastomer film 4 is stepped down into low-voltage DC power by the high-voltage electronic switch array 53 and the DC-DC step-down converter 54 and then sent to the common DC bus 55. At the node of the common DC bus 55, the two DC power sources are superimposed, and the merged DC power is uniformly input into the inverter circuit 56, modulated into constant frequency and constant voltage AC power that conforms to the grid specifications, and finally connected to the grid through the transmission lines in the composite umbilical cable 57.

[0045] During step S3, the energy management module 7 adjusts the power distribution between the dielectric elastomer film 4 and the permanent magnet synchronous generator 37 according to the real-time sea state. In low sea states, wave thrust is small, and the seawater plunger pump 31 cannot build sufficient pressure to drive the permanent magnet synchronous generator 37 to generate electricity efficiently. However, the dielectric elastomer film 4 is highly sensitive to small waves and can generate a significant voltage rise even with small deformations; therefore, the dielectric elastomer film 4 is the primary generator. In medium sea states, both the hydraulic generator track and the dielectric elastomer generator track have power generation capabilities, and both output power simultaneously. The energy management module 7 injects a portion of the electrical energy output from the dielectric elastomer film 4 into the excitation winding of the permanent magnet synchronous generator 37 to improve its power generation efficiency. In high sea states, wave energy is abundant, and the hydraulic generator track can output high power; therefore, the permanent magnet synchronous generator 37 is the primary generator, and all the electrical energy output from the dielectric elastomer film 4 is used to enhance the excitation efficiency of the permanent magnet synchronous generator 37.

[0046] In addition, during the cyclic execution of steps S1 to S3, the central controller 6 collects the voltage and current across the dielectric elastomer film 4 in real time via the high-voltage electronic switch array 53, and then calculates the real-time capacitance value and its first-order rate of change of the dielectric elastomer film 4, so that the dielectric elastomer film 4 also serves as a variable capacitance sensor for sea state self-sensing. When the rate of change of capacitance exceeds a set threshold, the central controller 6 determines it to be an overload sea state and initiates a dual defense mechanism: First, the central controller 6 instructs the high-voltage electronic switch array 53 to increase the voltage injected into the dielectric elastomer film 4 to the highest safe limit, causing the Maxwell stress generated to reach its extreme value. This electrically locks the free bending of the radial ribs 21, instantly increasing their stiffness and putting them into a forced wave-resistant state, while simultaneously increasing the mechanical energy extracted by the dielectric elastomer film 4 within the wave cycle. Second, the central controller 6 outputs an electrical control signal to fully open the safety relief valve 39, preventing the high-pressure seawater discharged by the seawater plunger pump 31 from entering the seawater hydraulic motor 35 and instead releasing it directly to the ocean at zero pressure. The entire system's hydraulic circuit instantly releases pressure and loses its rigid support, allowing the device to submerge under its own gravity and wave-following mechanism or completely unload, safely surviving the extreme sea state. Once the sea state returns to normal, the central controller 6 resumes normal power generation control, and the device re-enters the cyclic power generation process of steps S1 to S3.

[0047] Step S4 involves cyclically executing steps S1 to S3 throughout a continuous wave cycle to achieve continuous power generation. Due to the radially symmetrical structure of the biomimetic jellyfish umbrella 1, the device can capture wave energy from any direction without adjusting its posture. The return spring 22 in the flexible frame 2 ensures the reliable opening and closing of the biomimetic jellyfish umbrella 1 in each wave cycle. The all-seawater hydraulic system 3, using seawater as the working medium, fundamentally eliminates the risk of mineral hydraulic oil leakage and ocean pollution. Therefore, the device repeatedly experiences wave crest contraction power generation and wave trough expansion complementary power generation throughout the continuous wave cycle. The power conversion system 5 seamlessly connects the electrical energy from the hydraulic power generation track and the dielectric elastomer power generation track at the shared DC bus 55 in each wave cycle, and then continuously feeds it into the power grid via the inverter circuit 56 and the composite umbilical cable 57, achieving continuous and efficient power generation of wave energy across the entire frequency band.

[0048] A design method for a jellyfish-inspired wave energy power generation device, used to design the aforementioned jellyfish-inspired wave energy power generation device, includes the following steps: Sa: Bionic structure design steps; Sb: Wave energy input boundary design steps; Sc: Hydraulic power rail parameter design steps; Sd: Dielectric elastomer power generation rail parameter design steps; Se: Dual-rail grid connection verification and excitation efficiency enhancement design steps; Sf: Water absorption velocity and marine ecology verification steps; Sg: Energy management strategy design steps.

[0049] For example, in this embodiment of the invention, the steps of the above design method are sequentially connected and unfolded step by step, ultimately outputting a complete jellyfish biomimetic wave energy generation device. First, taking the radially symmetrical umbrella of a jellyfish as a biomimetic prototype, the hemispherical or near-hemispherical geometric shape of the biomimetic jellyfish umbrella 1 and the distribution of the radial flexible skeleton composed of the central hub 23, radial ribs 21 and return spring 22 are determined. The skeleton is then slightly arched upward in its natural state to store elastic potential energy, thereby giving the flexible skeleton 2 the function of elastic energy storage and release, laying the structural foundation for the reliable opening and closing of the umbrella in each wave cycle. Then, the dual-track power generation system integration design was carried out. On the one hand, the dielectric constant, elastic modulus, maximum tensile ratio, and pre-charge voltage range of the dielectric elastomer film 4 were determined, so that it could generate significant deformation and voltage rise under small deformation in low sea states, thereby ensuring power generation capacity in low sea states. On the other hand, the working pressure of the full seawater hydraulic system 3 was set to 10-20 MPa, and the displacement of the seawater plunger pump 31 was matched with the contraction stroke of the biomimetic jellyfish umbrella 1, thereby ensuring high power output under large waves. Next, the full seawater open circulation design was carried out, so that the full seawater hydraulic system 3 directly draws the surrounding seawater as the working medium, fundamentally eliminating the risk of mineral hydraulic oil leakage and ocean pollution. All flow channels and valves are made of seawater-resistant ceramic or polyetheretherketone materials to adapt to the seawater environment. The inlet is equipped with a micron-level antifouling filter to block impurities and marine organisms, and the outlet adopts a diffusion channel to reduce the discharge velocity and reduce the impact on the marine ecosystem. Next, compliant control and survivability design were implemented. A central controller 6 was configured to fully open the safety relief valve 39 under extreme sea conditions to unload hydraulic resistance. Simultaneously, the bias voltage injected into the dielectric elastomer film 4 was increased to the maximum safe limit via the high-voltage electronic switch array 53. Maxwell stress was used to increase the elastic damping of the radial ribs 21 to absorb high-frequency impact energy, allowing the biomimetic jellyfish umbrella 1 to unload with the waves after the hydraulic system was depressurized, thereby mitigating wave damage and preventing structural failure. Finally, an energy management strategy was designed, with an energy management module 7 configured to automatically adjust the power distribution between the dielectric elastomer power generation rail and the hydraulic power generation rail according to real-time sea conditions, achieving high-efficiency power generation across the entire frequency band. Thus, this design method, through the synergistic design of biomimetic structure, dual-rail power generation, open circulation in the entire seawater, compliant survivability control, and energy management strategy, enables the designed device to possess advantages such as omnidirectional response, wide-bandwidth high-efficiency power generation, high survivability, zero pollution, and low maintenance costs, comprehensively solving the problems of low power generation efficiency and low stability in existing technologies.

[0050] The following simulation examples provide a detailed explanation and quantitative verification of the above design method. This simulation example uses a typical moderate sea state as the baseline input.

[0051] (a) Simulation input reference: Sea state parameters and input power boundary The basic physical parameters are as follows: significant wave height Take 1.5m as an example, wave energy period The time frame is set to 5.0 s (corresponding to a wave circular frequency ω≈1.257 rad / s), the standard seawater density ρ is set to 1025 kg / m³, the gravitational acceleration g is set to 9.81 m / s², the reference capture width B of the device is set to 1.0 m, and the total mechanical power for target capture is... Take 5.0kW.

[0052] According to the formula for the average energy flux density per unit wave crest of irregular deep-water waves: ; Substituting all the reference parameters, the calculation yields: ; The condition for determining deep-water waves is that the water depth h ≥ / 2, the critical deep-water depth for this working condition is calculated to be approximately 19.52m; when the deployment water depth is insufficient, the deep-water approximation formula is prohibited, and the energy flow must be recalculated using the finite-water depth dispersion relation. Hydrodynamic capture width ratio (CWR) calculation: ; This value is the input boundary for high-performance simulation and cannot be directly extrapolated from sea state parameters alone. It needs to be combined with the biomimetic shape of the jellyfish umbrella 1, the stiffness of the radial ribs 21, and the wave incident angle to complete the hydrodynamic simulation verification.

[0053] (II) Quantitative verification of the all-seawater hydraulic power rail: The fixed parameters of the hydraulic system are as follows: the number of plunger groups n is 8, symmetrically arranged at a radial angle of 45° along the biomimetic jellyfish umbrella 1 to balance the oblique wave load; the plunger diameter D is 0.05m, which needs to be checked again in conjunction with the cylinder block structural strength and seawater corrosion intensity; the maximum reciprocating stroke of the plunger... A value of 0.12m is used, with one complete suction and discharge stroke completed in a single wave cycle; the rated operating pressure difference Δp of the system is taken as 13MPa, corrected by energy conservation; the plunger volumetric efficiency... A value of 0.90 is used as an example value for the micro-gap fit of silicon carbide ceramics; prototype flow calibration is required. The overall efficiency of the hydraulic motor... A value of 0.85 is used, which includes all mechanical losses such as friction and seawater shear; the baseline efficiency of the permanent magnet synchronous generator is 37. Take 0.90.

[0054] The calculation is performed step by step as follows: Single plunger cross-sectional area and single stroke displacement: ; ; Total geometric displacement of eight sets of plungers in a single cycle: ; Theoretical flow rate vs. actual effective average flow rate: ; ; Hydraulic power, motor shaft power, hydraulic rail output electrical power: ; ; ; The hydraulic power distribution ratio is shown in Table 1: Table 1 Hydraulic Power Distribution Ratio Table (III) Verification of the electromechanical coupling rail of the dielectric elastomer The fundamental equations for dielectric elastomer thin films 4 employ the assumptions of isoaxial biaxial tension and volumetric incompressibility. The fixed material and structural parameters are as follows: vacuum dielectric constant. =8.854×10 - ¹²F / m; relative permittivity of modified acrylate =4.7; Initial area of ​​a single thin film =2.15m²; initial film thickness =0.5mm; Maximum isotropic stretch ratio =2.0; Precharge bias voltage =2.0kV; Number of parallel thin-film devices connected to the whole machine: m=80 pieces.

[0055] Basic capacitance and electric field strength calculation: ; ; Minimum film thickness after stretching =0.125mm, mean tensile electric field strength: ; The energy difference of a single-cycle ideal electric field in a single thin film: ; This value represents only the theoretical lossless energy storage and does not include polymer viscoelastic hysteresis losses, thin-film micro-leakage, and high-voltage DC-DC converter switching losses. The net cycle efficiency is also included. After correction, the maximum ideal lossless power limit of the dielectric elastomer of the whole machine is: ; Actual output: .

[0056] (iv) Scenario Analysis of Dual-Rail Grid Connection and Controllable Excitation The hydraulic and dielectric elastomer energy pathways originate from the same source, with mechanical energy derived from the 5kW capture power of the biomimetic jellyfish umbrella 1. The total power for direct grid connection without coordination is: ; Ideal lossless limit ( )hour: .

[0057] Overall upper limit efficiency of mechanical energy transfer from the whole machine to grid-connected power: ; This efficiency only represents the power transmission and conversion efficiency, and does not include the hydrodynamic capture loss of the biomimetic jellyfish umbrella 1.

[0058] The applicable constraints and conditions for excitation efficiency enhancement are calculated as follows. Prerequisite: Electrically excited or hybrid-excited generators can utilize dielectric elastomer power excitation optimization. Taking the excitation distribution ratio α = 0.3, the generator efficiency after excitation optimization... =93.5%, the remaining 70% of the dielectric elastomer power is directly connected to the grid. Ideal limit example ( )hour: ; Optimized overall power transfer efficiency: ; Compared to direct grid connection, the net increase in power generation is ΔP = 3565.61. 3459.89≈105.72W. The prerequisite for efficiency improvement is that the increase in generator efficiency brought about by excitation must be greater than the output loss caused by the power consumed by the dielectric elastomer during excitation; otherwise, there is no value in improving efficiency.

[0059] (v) Verification of water intake velocity and marine ecology The biomimetic jellyfish bell-shaped cap 1's rebound and water absorption process occupies half a wave cycle, that is... The water absorption flow rate is treated as a sinusoidal pulsation, with a peak value coefficient of π / 2. The calculation is as follows: ; ; The ecological reference limit is 0.1524 m / s (corresponding to 0.5 ft / s, based on the conservative comparison standard for cooling water intake in 40 CFR §125.94; this device is not directly subject to the mandatory constraints of this regulation). Filter screen opening ratio. Take 0.45. This satisfies the 20% blockage requirement. The minimum filter area is: ; Engineering values Clean and clog-free operating conditions ( The maximum flow velocity was 0.1196 m / s at 20% area bioclogging condition. The maximum flow velocity was 0.1495 m / s. The flow velocity under both operating conditions was below the ecological reference limit of 0.1524 m / s.

[0060] Ecological boundary explanation: A flow velocity lower than the reference value only indicates a lower risk of suction and cannot be used to determine that the device is completely free of marine life damage; a complete ecological assessment requires a comprehensive demonstration of the mesh size, water suction frequency, marine biological population, and environmental impact assessment report.

[0061] Therefore, the above simulation examples, through step-by-step quantitative verification of wave energy input boundary, hydraulic power rail power chain, dielectric elastomer electromechanical coupling rail energy storage and power generation, dual-rail grid connection and excitation efficiency, as well as water intake velocity and marine ecology, have verified the technical feasibility and completeness of each step of the design method, and provided a quantitative design basis for the engineering implementation of the device.

[0062] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising” or “including” and similar terms mean that the elements or objects preceding “comprising” or “including” encompass the elements or objects listed following “comprising” or “including” and their equivalents, and do not exclude other elements or objects. The terms “connected” or “linked” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0063] The above description is merely an optional embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A jellyfish-inspired wave energy power generation device, characterized in that, include: The biomimetic jellyfish umbrella (1), flexible skeleton (2), full seawater hydraulic system (3), dielectric elastomer film (4) and power conversion system (5); The biomimetic jellyfish umbrella (1) has a radially symmetrical structure; The flexible skeleton (2) is disposed inside the bionic jellyfish umbrella (1) to provide support for the bionic jellyfish umbrella (1), and to drive the bionic jellyfish umbrella (1) to contract under the action of waves, and to drive the bionic jellyfish umbrella (1) to expand when the waves recede. The full seawater hydraulic system (3) uses the surrounding seawater as the working medium to convert the kinetic energy generated by the contraction and expansion of the biomimetic jellyfish umbrella (1) into electrical energy; The dielectric elastomer film (4) is attached to the biomimetic jellyfish umbrella cover (1); The power conversion system (5) is connected to the full seawater hydraulic system (3) and the dielectric elastomer film (4) respectively, and is used to combine the electrical energy output by the full seawater hydraulic system (3) and the electrical energy output by the dielectric elastomer film (4) and then output them. The flexible skeleton (2) includes eight radial ribs (21), eight return springs (22), and a central hub (23); the central hub (23) is fixedly disposed at the center of the bionic jellyfish umbrella cover (1), the eight radial ribs (21) are evenly spaced along the circumference of the central hub (23), the root of each radial rib (21) is fixed to the central hub (23), and the free end extends to the edge of the bionic jellyfish umbrella cover (1) and is fixed thereto; the return springs (22) are used to drive the bionic jellyfish umbrella cover (1) and the flexible skeleton (2) to recover; The all-seawater hydraulic system (3) includes a seawater plunger pump (31) driven by the radial ribs (21), a suction check valve (32) located at the inlet of the seawater plunger pump (31), a pressure check valve (33) located at the outlet, a bladder accumulator (34), a seawater hydraulic motor (35), a high-pressure manifold (36), a permanent magnet synchronous generator (37), a filter (38), and a safety relief valve (39). The middle part of the radial ribs (21) is connected to the piston rod (311) of the seawater plunger pump (31) via a hinge or ball joint. The seawater plunger pump (31) drives the seawater hydraulic motor (35) via the high-pressure manifold (36). The pressure motor (35) is connected to the permanent magnet synchronous generator (37) to convert the kinetic energy generated by the contraction and expansion of the bionic jellyfish umbrella (1) into electrical energy. The filter (38) is located at the inlet of the seawater plunger pump (31). The inlet of the seawater plunger pump (31) is connected to the main inlet pipe (30) via the suction check valve (32). The outlet of the seawater plunger pump (31) is connected to the high-pressure water collection main pipe (36) via the pressure check valve (33). The bladder-type accumulator (34) is connected in parallel to the high-pressure water collection main pipe (36) and is filled with nitrogen. The safety overflow valve (39) is connected between the high-pressure water collection main pipe (36) and the ocean.

2. The jellyfish-inspired wave energy power generation device according to claim 1, characterized in that, The biomimetic jellyfish umbrella cover (1) is a load-bearing shell made of flexible polymer material and fiber-reinforced composite structure. Its overall geometric shape is hemispherical or approximately hemispherical, and its thickness gradually decreases from the center to the edge. The dielectric elastomer film (4) is attached to the outer surface or between the inner and outer surfaces of the biomimetic jellyfish umbrella cover (1) and adopts a three-layer composite structure. The middle layer of the three-layer composite structure is an acrylic elastomer. The upper and lower surfaces of the middle layer are respectively coated with a flexible electrode layer composed of single-walled carbon nanotubes and polydimethylsiloxane composite conductive paste.

3. The jellyfish-inspired wave energy power generation device according to claim 1, characterized in that, The power conversion system (5) includes a rectifier circuit (51), an initial bias power supply (52), a high-voltage electronic switch array (53), a DC-DC buck converter (54), a common DC bus (55), an inverter circuit (56), and a composite umbilical cable (57); the output terminal of the permanent magnet synchronous generator (37) is connected to the common DC bus (55) via the rectifier circuit (51); the dielectric elastomer film (4) is connected to the common DC bus (55) via the high-voltage electronic switch array (53) and the DC-DC buck converter (54), and the initial bias power supply (52) is connected to the common DC bus (55). The bias power supply (52) provides bias charge to the dielectric elastomer film (4) via the high-voltage electronic switch array (53); the common DC bus (55) is connected to the composite umbilical cable (57) via the inverter circuit (56) and is connected to the power grid via the composite umbilical cable (57); the high-voltage electronic switch array (53) is configured to inject bias voltage into the dielectric elastomer film (4) by the initial bias power supply (52) when a wave load is input, and adjust the mechanical energy extracted by the dielectric elastomer film (4) during the wave cycle by adjusting the amplitude of the bias voltage.

4. The jellyfish-inspired wave energy power generation device according to claim 3, characterized in that, It also includes a central controller (6), which calculates the real-time capacitance value and its rate of change of the dielectric elastomer film (4) online via the high-voltage electronic switch array (53). The central controller (6) is configured to determine an overload sea state when the rate of change of the capacitance value exceeds a set threshold, and to perform the following actions in conjunction: increase the voltage injected into the dielectric elastomer film (4) via the high-voltage electronic switch array (53) to increase the mechanical energy extracted by the dielectric elastomer film (4) within the wave cycle, and at the same time drive the safety overflow valve (39) to fully open so that the seawater discharged by the seawater plunger pump (31) is depressurized directly to the ocean without passing through the seawater hydraulic motor (35).

5. The jellyfish-inspired wave energy power generation device according to claim 4, characterized in that, The dielectric elastomer film (4) and the permanent magnet synchronous generator (37) perform spatiotemporal phase complementary convergence at the common DC bus (55); during the pressurized water power generation period when the wave crest arrives and the radial rib (21) is pressed down, the seawater hydraulic motor (35) drives the permanent magnet synchronous generator (37) to output main power to the common DC bus (55) through the rectifier circuit (51), and the dielectric elastomer film (4) is stretched and charged by the initial bias power supply (52); during the trough of the wave or the hydraulic commutation dead zone period, the seawater plunger pump (31) enters water suction reset, the output of the permanent magnet synchronous generator (37) decreases, and the dielectric elastomer film (4) rebounds and contracts, causing its voltage to rise. Electrical energy is injected into the common DC bus (55) through the high-voltage electronic switch array (53) and the DC-DC step-down converter (54) to fill the power gap during the hydraulic commutation dead zone period.

6. The jellyfish-inspired wave energy generation device according to claim 5, characterized in that, It also includes an energy management module (7), which is configured to adjust the power distribution between the dielectric elastomer film (4) and the permanent magnet synchronous generator (37) according to the real-time sea state: in low sea state, the dielectric elastomer film (4) generates the main power; in medium sea state, both output power simultaneously, and inject part of the electrical energy output by the dielectric elastomer film (4) into the excitation winding of the permanent magnet synchronous generator (37); in high sea state, the permanent magnet synchronous generator (37) generates the main power, and uses the electrical energy output by the dielectric elastomer film (4) for the excitation efficiency enhancement of the permanent magnet synchronous generator (37).

7. A jellyfish-inspired wave energy power generation method, based on the jellyfish-inspired wave energy power generation device as described in any one of claims 1 to 6, characterized in that, Includes the following steps: S1: When waves arrive, the biomimetic jellyfish umbrella (1) captures wave energy from any direction through its radially symmetrical structure. The flexible skeleton (2) causes the biomimetic jellyfish umbrella (1) to contract under the action of waves. The full seawater hydraulic system (3) uses the surrounding seawater as the working medium to convert the kinetic energy generated by the contraction of the biomimetic jellyfish umbrella (1) into electrical energy. At the same time, the dielectric elastomer film (4) attached to the biomimetic jellyfish umbrella (1) deforms synchronously with the contraction of the biomimetic jellyfish umbrella (1), and uses the capacitance change generated by the deformation to convert mechanical energy into electrical energy. S2: When the waves recede, the flexible skeleton (2) drives the bionic jellyfish umbrella (1) to expand. The full seawater hydraulic system (3) converts the kinetic energy generated by the expansion of the bionic jellyfish umbrella (1) into electrical energy. At the same time, the dielectric elastomer film (4) recovers its deformation as the bionic jellyfish umbrella (1) expands, and uses the capacitance change generated by the deformation to convert mechanical energy into electrical energy. S3: The power conversion system (5) combines the electrical energy output by the full seawater hydraulic system (3) with the electrical energy output by the dielectric elastomer film (4) and outputs it. S4: In the continuous wave cycle, steps S1 to S3 are executed cyclically to achieve continuous power generation.

8. A design method for a jellyfish-inspired wave energy power generation device, used to design the jellyfish-inspired wave energy power generation device as described in claim 6, characterized in that, Includes the following steps: Sa: Bionic structure design steps: Taking the radially symmetrical umbrella of a jellyfish as the bionic prototype, the overall geometric shape of the bionic jellyfish umbrella (1) is determined to be hemispherical or approximately hemispherical, with the thickness gradually decreasing from the center to the edge; the distribution form of the flexible skeleton (2) is determined, so that the eight radial ribs (21) are evenly spaced along the circumference of the central hub (23), and the free ends of each radial rib (21) extend to the edge of the bionic jellyfish umbrella (1) and are fixed. The reset spring (22) causes the flexible skeleton (2) to arch slightly upward in its natural state to store elastic potential energy, giving it elastic energy storage and release functions; Sb: Wave energy input boundary design steps: Determine the significant wave height based on measured sea state data of the target deployment area. With wave energy cycle The wave energy flux density is calculated using the formula for the average energy flux density per unit wave crest of irregular deep-water waves: ； In the formula, Let ρ be the average energy flux density per unit wave crest, ρ be the density of seawater, and g be the acceleration due to gravity; and determine the reference capture width B of the device and the total mechanical power of target capture. The following formula was used to verify the capture width ratio: ； When the capture width ratio exceeds the preset threshold, hydrodynamic simulation verification needs to be completed by combining the biomimetic shape of the biomimetic jellyfish umbrella (1), the stiffness of the radial ribs (21), and the wave incident angle. Sc: Hydraulic power rail parameter design steps: Determine the plunger diameter D and the maximum reciprocating stroke of the seawater plunger pump (31). The system's rated operating pressure difference Δp is used to match the displacement of the seawater plunger pump (31) with the contraction stroke of the biomimetic jellyfish umbrella (1); the hydraulic rail output power is calculated and verified step by step according to the following hydraulic power chain closed-loop equation set: ； ； ； ； ； ； ； ； In the formula, Let be the cross-sectional area of ​​the plunger. It is a single-cylinder, single-stroke displacement. Let n be the total geometric displacement of n groups of plungers in a single cycle. For theoretical flow rate, This represents the actual effective average flow rate. For plunger volumetric efficiency. The hydraulic power at the motor inlet. For the overall mechanical efficiency of hydraulic motors, This refers to the output shaft power of the hydraulic motor. The reference efficiency of the permanent magnet synchronous generator (37) is given. The final grid-connected power of the hydraulic rail; the working pressure of the all-seawater hydraulic system (3) should be within the range of 10 to 20 MPa during the design process; Sd: Design steps for dielectric elastomer power generation rail parameters: Determine the relative permittivity of the dielectric elastomer film (4). Initial area of ​​a single thin film Initial film thickness Maximum isotropic stretch ratio Precharge bias voltage and the number of parallel thin films in the whole machine (m); Calculate the output power of the dielectric elastomer generator rail according to the following set of electromechanical coupling equations: ； ； ； ； In the formula, This is the initial capacitance value of the thin film. The vacuum permittivity, This is the capacitance value when the film is stretched to its maximum. This represents the ideal energy storage difference in a single-cycle constant-voltage mode for a single thin-film membrane. For the net efficiency of the cycle, This represents the actual output power of the dielectric elastomer of the entire machine; during the design process, it should be checked that the electric field strength inside the film after stretching does not exceed the material breakdown field strength. Se: Dual-rail grid connection verification and excitation efficiency design steps: Directly add the output power of the hydraulic rail to the output power of the dielectric elastomer power generation rail, and calculate the total power and overall power transfer efficiency of the non-cooperative direct grid connection according to the following formula: ； ； In the formula, To capture the total mechanical power for the target; when the permanent magnet synchronous generator (37) adopts an electrically excited or hybrid excited structure, a certain proportion α of the output power of the dielectric elastomer generator rail is injected into the excitation winding of the permanent magnet synchronous generator (37) to improve the generator efficiency. The total grid-connected power after excitation efficiency enhancement is calculated according to the following formula: ； In the formula, The excitation efficiency is calculated using α, where α is the excitation allocation ratio. The excitation efficiency enhancement scheme is adopted only when the total grid-connected power after excitation enhancement is greater than the total grid-connected power without coordination. Sf: Water absorption velocity and marine ecology verification steps: Calculate the water absorption flow rate of the biomimetic jellyfish umbrella (1) during the rebound water absorption process, and verify the maximum transient velocity at the filter (38) according to the following formula: ； ； ； In the formula, The time for the water absorption process. This represents the average water absorption flow rate. This represents the peak water absorption flow rate. This refers to the total area of ​​the filter screen outer casing. For open area ratio, The clogging area coefficient should be used; during the design process, the maximum transient flow velocity should be kept below the ecological reference limit, and the minimum filter area should be determined by back-calculation based on the verification results. Sg: Energy management strategy design steps: Configure the energy management module (7) to automatically adjust the power distribution between the dielectric elastomer film (4) and the permanent magnet synchronous generator (37) according to the real-time sea state: the dielectric elastomer film (4) generates the main power in low sea state; both output power in medium sea state; the permanent magnet synchronous generator (37) generates the main power in high sea state; Configure the central controller (6) to control the safety overflow valve (39) to fully open in extreme sea state to unload hydraulic resistance, and adjust the bias voltage injected into the dielectric elastomer film (4) through the high-voltage electronic switch array (53) to achieve active survival control.

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