Power generation system of underwater vehicle capable of continuously running infinitely

Abstract

The invention relates to the technical field of aircraft power generation, and discloses a power generation system of an unlimited continuous underwater aircraft, which comprises a main body frame, a wave energy capturing unit, a solar power generation unit, a transmission and power generation unit and a control and energy storage unit, the main body frame adopts a corrosion-resistant steel structure, a latticed photovoltaic mounting area is arranged at the top of the main body frame, and reinforcing ribs and connecting seats connected with the rotary wings are arranged below the main body frame; the wave energy capturing unit comprises rotary wing modules symmetrically arranged on the two sides of the main body frame. A wave energy capturing unit and a solar power generation unit are compositely integrated, an impeller type capturing piece and a permanent magnet synchronous generator are driven by reciprocating swing of rotary wings on the two sides to operate cooperatively, and meanwhile flexible solar cell modules are arranged on the top of a main body frame and the surfaces of the two wings. Parallel collection and complementary power supply of wave energy and solar energy on the same carrier are realized, and all-weather and multi-mode energy capture and continuous power supply of an underwater vehicle in a complex marine environment are realized.

Description

A power generation system for an underwater vehicle with unlimited endurance Technical Field

[0001] This invention relates to the field of vehicle power generation technology, specifically to a power generation system for an underwater vehicle with unlimited range. Background Technology

[0002] In the fields of marine resource development and underwater exploration, autonomous underwater vehicles (AUVs) are core equipment for long-term observation, seabed mapping, and resource exploration. The sustainability and stability of their energy supply systems directly determine their operational radius and mission cycle. With the continuous expansion of marine exploration depth and breadth, traditional battery or cable-based power supply methods are no longer sufficient to meet the needs of long-term underwater operations far from shore. Developing autonomous power supply systems based on renewable marine energy sources has become a key direction for technological development in this field.

[0003] Solar energy, as the most stable renewable energy source in the marine environment, has seen its photovoltaic conversion technology mature in applications at the surface and near-water depths. However, traditional rigid solar panels suffer from drawbacks such as brittleness, weak impact resistance, and difficulty in fitting curved structures, making them prone to encapsulation damage and performance degradation in underwater high-pressure, high-salt-spray, and wave-impact environments. In recent years, flexible thin-film solar cell technology, through the use of bendable substrates and novel functional materials, has significantly improved mechanical flexibility and environmental adaptability while maintaining photoelectric conversion efficiency, providing a new technological path for underwater photovoltaic applications.

[0004] Wave energy, as an important component of marine renewable energy, has a global theoretical reserve exceeding 29,000 TW, characterized by high energy density, wide distribution, and strong predictability. Current wave energy conversion technologies are mainly based on the principles of oscillating water column, leaping wave, and nodding duck wave, converting the reciprocating motion of waves into electrical energy through mechanical transmission mechanisms or direct-drive generators. However, underwater vehicles, limited by their size and navigation stability, cannot directly apply the capture and conversion structures of large-scale wave power plants. Existing wave energy harvesting devices suitable for underwater platforms generally suffer from technical bottlenecks such as low energy capture efficiency, narrow response bandwidth, and poor adaptability to sea conditions.

[0005] Existing publicly available technical solutions have made beneficial explorations in integrating multiple marine energy sources. Patent application CN119840812A uses a permanent magnet linear motor as the core of wave energy generation, adapting to underwater low-frequency, high-amplitude wave conditions through a sealed cabin and shock-absorbing structure. However, this solution only addresses wave energy as a single energy form and does not consider synergistic complementarity with solar energy. Patent CN219643818U discloses a power generation device coupling wave, wind, and solar energy, expanding the light-gathering range through triangular solar panels. However, the irregular structure significantly increases manufacturing costs and makes splicing and sealing difficult, posing a risk of water seepage and corrosion in the high-humidity, high-salt marine environment. Patent application CN117081466A provides an adaptive control type wave-solar hybrid power generation system, achieving the capture and conversion integration of the two energy sources. However, under extreme conditions of continuous rain and low wave conditions, there is still a risk of power outage. The patent with publication number CN118508839A discloses a combined power generation device based on wave energy and solar energy, which integrates multiple modes such as hydropower, air power generation and photovoltaic power generation. However, it does not clearly define the power distribution and coordination control mechanism between different power generation units, making it difficult to guarantee the stability of system operation.

[0006] A comprehensive analysis of existing technologies reveals three common technical shortcomings in current underwater vehicle power generation systems: First, the energy source is singular or simply stacked, with each power generation module operating independently and lacking an effective energy complementarity mechanism, making it difficult to maintain stable power supply under complex and variable sea conditions. Second, the integration of the power generation unit and the carrier structure is low; traditional planar photovoltaic panels occupy a large space and have weak impact resistance, while wave energy capture devices are complex and heavy, severely affecting the hydrodynamic performance and maneuverability of the vehicle. Third, the output characteristics of different power generation modules vary significantly, requiring multi-stage DC-DC converters for voltage matching and power regulation, increasing system complexity, energy loss, and failure risks, which is detrimental to long-term reliable underwater operation. Therefore, there is an urgent need to develop a new type of underwater vehicle power generation system with a compact structure, strong energy complementarity, and high conversion efficiency. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a power generation system for an underwater vehicle with unlimited range, solving the problems mentioned in the background section.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solution: a power generation system for an underwater vehicle with unlimited endurance, comprising a main frame, a wave energy capture unit, a solar power generation unit, a transmission and power generation unit, and a control and energy storage unit;

[0009] The main frame is made of corrosion-resistant steel structure, with a grid-like photovoltaic installation area at the top and reinforcing ribs and connecting bases for connecting to the rotating wings at the bottom;

[0010] The wave energy capture unit includes rotating wing modules symmetrically arranged on both sides of the main frame. The rotating wings are made of fiberglass composite material and are connected to the main frame through a hinge shaft to achieve 0 to 45 degrees of swing. Four sets of impeller-type capture elements are evenly arranged on the surface of each rotating wing. Each set of impeller-type capture elements is directly connected to a permanent magnet synchronous generator through gears.

[0011] The solar power generation unit is installed in the grid-like photovoltaic installation area at the top of the main frame. It adopts a matrix-layout flexible a-Si solar cells. The surface of the solar cells is coated with an organosilicon-modified coating, and the frame is made of nano-composite aluminum alloy.

[0012] The transmission and power generation unit includes a linkage-gear transmission mechanism and an inverter. The reciprocating oscillation of the rotor is converted into the continuous rotational motion of the generator rotor through the linkage-gear mechanism. The four rotor power generation modules and a single solar sub-array are electrically connected in series to form a DC link and are directly connected to the inverter.

[0013] The control and energy storage unit includes a lithium battery pack, a multi-port converter, a water flow sensor, a light power sensor, and a wave energy power monitoring sensor. The sensors detect environmental parameters in real time and transmit them to the control unit. The control unit adjusts the output ratio of the two energy sources and controls the energy storage process through an algorithm.

[0014] Preferably, the rotary wing is connected to the main frame via a hinge shaft and is limited to reciprocating oscillation within an angle range of 0°–45°. This oscillation range is preferably determined based on the wave statistical characteristics of the target sea area and the lift-drag characteristic curve of the hydrofoil, so that the rotary wing is always in the optimal angle of attack range under common wave height to period combinations, thereby maximizing the wave excitation torque and continuously capturing wave energy.

[0015] Preferably, the impeller-type capture component includes a first guide impeller and a second guide impeller. Both the first guide impeller blades and the second guide impeller blades maintain an angle of 15 to 45 degrees with the plane. The impellers are distributed around the upper and lower surfaces of the rotating impeller and are directly connected to a permanent magnet synchronous generator through gears to convert mechanical motion into direct current.

[0016] Preferably, the optimal bandgap, depth, and curvature configuration of the flexible a-Si solar cell enables a photoelectric conversion efficiency of 59.8%, and the organosilicon-modified coating on the surface of the solar cell, together with the nanocomposite aluminum alloy frame, provides salt spray resistance.

[0017] Preferably, the linkage-gear set in the transmission and power generation unit smoothly converts the reciprocating oscillation of the rotor into the continuous rotation of the generator to avoid mechanical impact. The rotor power generation module and the solar power generation unit are electrically connected in series to form a high-voltage DC power that is directly input to the inverter, eliminating the need for DC-DC conversion equipment and reducing power transmission loss.

[0018] Preferably, the lithium battery pack in the control and energy storage unit stores surplus electrical energy to meet the power supply needs when there is no energy input for 3 days. A water flow sensor is embedded in the side of the rotating wing to detect the water flow speed and direction. A light power sensor and a wave energy power monitoring sensor output solar power generation signal and wave energy power generation signal in real time, respectively. A multi-port converter is connected to the output end of the solar power generation unit and the wave energy capture unit to adjust unstable power and output stable power.

[0019] Preferably, the control unit performs the following power supply mode switching based on the sensor detection results:

[0020] When the solar power is greater than or equal to 500 milliwatts and the wave energy power is greater than or equal to 300 milliwatts, the system enters full power mode. The solar power generation unit and the wave energy capture unit supply power to the vehicle in parallel and input the excess energy into the lithium battery pack for storage.

[0021] When the solar power is greater than or equal to 500 milliwatts and the wave power is less than 300 milliwatts, the control unit switches to the solar single-phase power supply mode.

[0022] When the solar power is less than 500 milliwatts and the wave power is greater than or equal to 300 milliwatts, the control unit switches to the wave power single-phase power supply mode.

[0023] When the solar power is less than 500 milliwatts and the wave power is less than 300 milliwatts, the lithium battery pack serves as the main power source to supply power to the vehicle.

[0024] Preferably, when the water flow sensor detects that the water flow velocity is too high and turbulence is formed, the control unit drives the motor to control the impeller shaft to rotate in the opposite direction for fine adjustment to reduce impeller impact; when the water flow sensor detects that the water flow velocity is within the normal range, the control unit adjusts the impeller attitude so that the impeller disk surface is always perpendicular to the water flow direction to achieve the best wave energy collection efficiency.

[0025] Preferably, the four rotating wing power generation modules and a single solar subarray are electrically connected in series to form a DC link, which superimposes the output voltage of the wave energy power generation unit onto the photovoltaic voltage to achieve automatic voltage boosting. The high-voltage DC power after series connection is directly connected in parallel to the DC bus and connected to the inverter to be converted into AC power.

[0026] This invention provides a power generation system for an underwater vehicle with unlimited range. It has the following advantages:

[0027] 1. This invention integrates a wave energy capture unit with a solar power generation unit. The reciprocating oscillation of the rotating wings on both sides drives the impeller-type capture component and the permanent magnet synchronous generator to operate in coordination. At the same time, flexible solar cell modules are arranged on the top of the main frame and the surface of the two wings, so that wave energy and solar energy can be collected in parallel and supplied in a complementary manner on the same carrier. This enables the underwater vehicle to capture energy and provide continuous power in all weather and multimodal conditions in complex marine environments.

[0028] 2. This invention employs flexible a-Si solar cells in a matrix layout covering the main frame and rotor surface, combined with an encapsulation structure of organosilicon modified coating and nanocomposite aluminum alloy frame. By utilizing the bendable properties of flexible materials to adapt to the shape of the aircraft, and using a surface protective layer to resist seawater salt spray corrosion and underwater impact, this invention maximizes the solar energy absorption area within a confined space and significantly enhances the structural durability and long-term operational reliability of the power generation components in high-pressure underwater environments.

[0029] 3. This invention forms a DC link by sequentially connecting multiple rotating wing power generation modules and solar sub-arrays in series. The series topology allows the output voltage of the wave energy generation unit to be automatically superimposed on the photovoltaic voltage to achieve voltage boosting. This enables the high-voltage DC power to be directly connected in parallel to the DC bus and converted into AC power by an inverter, simplifying the design of the power transmission path. This eliminates the need for large DC-DC conversion equipment required in traditional solutions, reducing manufacturing costs and maintenance complexity while minimizing power loss during multi-stage conversion, and significantly improving the energy conversion efficiency and operational reliability of the power supply system.

[0030] 4. This invention automatically and seamlessly switches between four-quadrant power supply modes based on the real-time power levels of solar and wave energy, and directly connects to the grid via a series DC link. Without the need for intermediate voltage transformation, it can continuously balance the source-load relationship under any sea state combination, maintain the stability of the bus voltage, and achieve stable power supply around the clock. Attached Figure Description

[0031] Figure 1 is a schematic diagram of the structure of the present invention.

[0032] Figure 2 is a schematic diagram of the flexible solar cell structure of the present invention;

[0033] Figure 3 is a schematic diagram of the side-wing spiral device of the present invention;

[0034] Figure 4 is a schematic diagram of the internal power generation device and energy storage device of the present invention. Detailed Implementation

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Please refer to Figures 1-4. This embodiment of the invention provides a power generation system for an underwater vehicle with unlimited endurance, including a main frame, a wave energy capture unit, a solar power generation unit, a transmission and power generation unit, and a control and energy storage unit.

[0037] The main frame is made of corrosion-resistant steel structure, with a grid-like photovoltaic installation area at the top and reinforcing ribs and connecting bases for connecting to the rotating wings at the bottom;

[0038] The wave energy capture unit includes rotating wing modules symmetrically arranged on both sides of the main frame. The rotating wings are made of fiberglass composite material and are connected to the main frame via hinge shafts to achieve a swing range of 0°–45°. Four sets of impeller-type capture elements are evenly arranged on the surface of each rotating wing. Each set of impeller-type capture elements is directly connected to a permanent magnet synchronous generator via gears. The rotating wings are connected to the main frame via hinge shafts and are limited to swing within the swing range of 0°–45°. This swing angle is adapted to the wave amplitude to ensure the continuity of kinetic energy capture.

[0039] The solar power generation unit is installed in the grid-like photovoltaic installation area at the top of the main frame. It adopts a matrix layout of flexible a-Si solar cells. The surface of the solar cells is coated with an organosilicon modified coating, and the frame is made of nano-composite aluminum alloy. The optimal band gap, depth and curvature configuration of the flexible a-Si solar cells enable a photoelectric conversion efficiency of 59.8%. The organosilicon modified coating on the surface of the solar cells and the nano-composite aluminum alloy frame together provide salt spray resistance.

[0040] Specifically, the wave energy capture unit achieves energy capture based on the principles of hydrodynamic energy conversion and electromechanical coupling. The rotating wing forms a double-wing oscillation mechanism through symmetrical arrangement, utilizing a hinged shaft to form a revolute pair with the main frame. This connection allows the rotating wing to oscillate reciprocally within a range of 0 to 45 degrees around the hinged shaft under the lift and drag generated by the periodic motion of wave particles. The angle range is selected based on the statistical characteristics of ocean waves; 0 degrees corresponds to a stationary state, while 45 degrees serves as the limiting oscillation angle to prevent mechanical collisions and ensure the reliability of the spring reset mechanism. The rotating wing is made of fiberglass composite material, which possesses anisotropic mechanical properties. Its specific strength and specific modulus meet the requirements for underwater weight reduction while providing sufficient bending stiffness, and the fiberglass-reinforced resin matrix is ​​chemically inert to seawater corrosive media.

[0041] The impeller-type capture components arranged on the surface of the rotating blade operate based on the principle of lift-type fluid machinery. The angle of attack of the first guide impeller and the second guide blade is set at 15 to 45 degrees, so that the pressure difference generated when the water flows over the blades creates torque, driving the impeller to rotate. This angle of attack range takes into account both start-up performance and operating efficiency. The small angle ensures start-up capability at low flow rates, while the large angle limits and prevents stalling caused by flow separation. The impeller and the permanent magnet synchronous generator are directly connected via gears, forming a direct conversion path from mechanical energy to electrical energy, avoiding energy loss in intermediate energy storage stages. The oscillating motion of the rotating blade and the rotational motion of the impeller form a two-stage energy extraction mechanism: the rotating blade captures the macroscopic potential energy changes of the waves, and the impeller captures the microscopic kinetic energy of the water flow. The synergistic effect of the two broadens the frequency range of the system response.

[0042] The solar power generation unit achieves light energy conversion based on the photovoltaic effect of amorphous silicon thin films. The flexible a-Si solar cells employ a matrix layout, which reduces mismatch losses caused by localized shading through optimized series-parallel topology. The optical bandgap of amorphous silicon is approximately 1.7 eV, exhibiting better matching with the solar spectrum than crystalline silicon. Furthermore, by adjusting the hydrogenation dilution ratio and substrate temperature during the deposition process, a bandgap gradient design is achieved, expanding the spectral response range. The cell depth (thickness) is controlled at the micrometer level, far less than the millimeter-level thickness of crystalline silicon cells. This thin-film structure allows the diffusion length of photogenerated carriers to match the depletion layer thickness, reducing bulk recombination losses. The curvature configuration is based on the underwater light field distribution characteristics. The deformation capability of the flexible substrate creates a micro-arc structure on the cell surface, increasing the probability of receiving scattered light while adapting to the curved shape of the vehicle's hull.

[0043] The surface-coated silicone-modified coating, based on the chemical structure of the polysiloxane backbone, forms a Si-O-Si bond network. This network possesses low surface energy and hydrophobic properties, effectively blocking chloride ion penetration from seawater and preventing electrode corrosion of the photovoltaic module. Organic modification groups (such as methyl and phenyl) in the coating provide flexibility, accommodating thermal expansion and contraction caused by temperature differences. The nanocomposite aluminum alloy frame is a composite material made by adding nano-alumina or silicon carbide particles to an aluminum matrix. The nanoparticles improve the yield strength of the material through a dispersion strengthening mechanism, while the refined grain boundary structure hinders the electrochemical corrosion process. This allows the frame to withstand mechanical loads while also possessing seawater corrosion resistance, ensuring the long-term sealing integrity of the encapsulation structure.

[0044] The linkage-gear set in the transmission and power generation unit smoothly converts the reciprocating oscillation of the rotor into the continuous rotation of the generator to avoid mechanical impact. The rotor power generation module and the solar power generation unit are electrically connected in series to form high-voltage direct current. This high-voltage direct current is directly connected in parallel to the DC bus and then connected to the inverter, eliminating the need for DC-DC conversion equipment to reduce power transmission loss.

[0045] The control and energy storage unit includes a lithium battery pack, a multi-port converter, a water flow sensor, a solar power sensor, and a wave energy power monitoring sensor. The sensors detect environmental parameters in real time and transmit them to the control unit. The control unit uses algorithms to adjust the output ratio of the two energy sources and control the energy storage process. The lithium battery pack in the control and energy storage unit stores surplus energy to meet the power supply needs during three days without energy input. The water flow sensor is embedded in the side of the rotating wing to detect water flow speed and direction. The solar power sensor and wave energy power monitoring sensor output solar power and wave power signals in real time, respectively. The multi-port converter is connected to the output terminals of the solar power generation unit and the wave energy capture unit to regulate unstable power and output stable power.

[0046] Specifically, the control and energy storage unit constructs a closed-loop control architecture of sensors, controllers, and actuators based on the principles of multi-source information fusion and adaptive power management. A water flow sensor is embedded in the side of the rotor blade, detecting the instantaneous velocity and direction vector of the surrounding water flow based on the Doppler effect or piezoresistive effect. This data is used not only to assess the real-time intensity of wave energy resources but also to provide feedback signals for impeller attitude adjustment. A photovoltaic reference cell or photodiode array is used to monitor the incident light irradiance in real time and convert it into an electrical signal. A wave energy power monitoring sensor detects the output voltage, current, and frequency of the permanent magnet synchronous generator and calculates real-time mechanical and electrical power by combining mechanical transmission parameters. These sensors transmit analog signals to the control unit after analog-to-digital conversion, forming a digital perception of the environmental energy state.

[0047] The control unit automatically switches power supply modes according to preset thresholds based on real-time environmental parameters and power generation signals detected by water flow sensors, optical power sensors, and wave energy power monitoring sensors.

[0048] When the solar power is ≥500mW and the wave power is ≥300mW, the system enters full power mode, the solar power generation unit and the wave energy capture unit supply power in parallel, and the excess energy is stored in the lithium battery pack.

[0049] When the solar power is ≥500mW and the wave power is <300mW, switch to solar single-phase power supply mode;

[0050] When the solar power is less than 500mW and the wave power is greater than or equal to 300mW, switch to wave power single-phase power supply mode.

[0051] When the solar power is less than 500mW and the wave power is less than 300mW, the lithium battery pack provides independent power.

[0052] By switching between the above modes, stable power supply in all weather conditions and multiple modes can be achieved.

[0053] The impeller-type capture device includes a first guide impeller and a second guide impeller. Both the first guide impeller and the second guide impeller maintain an angle of 15 to 45 degrees with the plane. The impellers are distributed around the upper and lower surfaces of the rotating impeller and are directly connected to a permanent magnet synchronous generator through gears to convert mechanical motion into direct current.

[0054] When the water flow sensor detects that the water flow velocity is too high and turbulence is formed, the control unit drives the motor to control the impeller shaft to rotate in the opposite direction to reduce impeller impact; when the water flow sensor detects that the water flow velocity is within the normal range, the control unit adjusts the impeller attitude so that the impeller disk surface is always perpendicular to the water flow direction to achieve the best wave energy collection efficiency.

[0055] Specifically, the impeller-type capture component adopts a dual-flow-channel impeller configuration, with the first and second guide impellers forming a composite structure that is either tandemly connected or coaxially nested. The installation angle (angle of attack) of the first and second guide blades, ranging from 15 to 45 degrees, is determined based on airfoil lift theory. This angle range is before the stall critical angle, causing a low-pressure zone to form on the back surface when water flows over the blades, thus generating a lift component. This lift generates a driving torque on the shaft; simultaneously, the pressure difference on the front surface generates a drag component. The resultant torque of lift and drag drives the impeller to rotate. 15 degrees as the lower limit ensures sufficient starting torque under low flow conditions, preventing the blades from failing to start due to flow separation in slow water flow; 45 degrees as the upper limit prevents dynamic stall caused by boundary layer separation at high angles of attack, maintaining high hydraulic efficiency. The impellers are arranged around the upper and lower surfaces of the rotating blade. This spatial arrangement ensures that regardless of whether the water flow direction is from above or below (corresponding to the crest and trough phases of the waves), the impellers are always in an effective working posture, achieving full-cycle adaptation to the reciprocating motion characteristics of the waves and improving the probability of energy capture in bidirectional flow. The impeller shaft is directly connected to the rotor of the permanent magnet synchronous generator via a gear speed-increasing mechanism. The gear transmission ratio is designed to match the low-speed, high-torque requirements of the impeller with the high-speed, low-torque requirements of the generator. The permanent magnet synchronous generator is based on the law of electromagnetic induction. It utilizes the magnetic field generated by the rotor's permanent magnets to cut magnetic field lines with the relative motion of the stator windings, inducing an alternating electromotive force in the windings, which is then rectified and converted into direct current output.

[0056] The flow sensor collects flow field data in real time and identifies the flow regime by measuring the intensity of flow velocity fluctuations, turbulence intensity coefficient, or Reynolds number characteristic value. When the flow velocity is detected to be too high and the turbulence intensity exceeds the threshold, it indicates that the incoming flow is in an unsteady turbulent state. At this time, the control unit activates the protection mode: the servo motor drives the impeller shaft to rotate in the opposite direction for fine adjustment, reducing the blade angle of attack or making the impeller plane form a certain angle with the direction of the incoming flow. By changing the attitude of the blades relative to the resultant velocity vector, the drag impact component and vortex-induced vibration intensity in the hydrodynamic load are reduced, and the risk of structural stress concentration and fatigue damage is reduced. When the flow velocity is detected to be within the normal range and the turbulence intensity is low, the control unit switches to the high-efficiency capture mode: the impeller attitude is adjusted through the closed-loop feedback control algorithm so that the normal direction of the impeller disk surface is parallel to the flow velocity vector (i.e., the impeller disk surface is perpendicular to the direction of the flow). At this time, the projected area of ​​the impeller in the flow field is the largest. According to the Betz limit theory, the theoretical maximum wind energy / hydropower utilization coefficient of fluid machinery is 16 / 27. The vertical alignment attitude makes the actual power coefficient close to the theoretical limit, realizing the optimization of wave energy conversion efficiency. This adaptive control mechanism automatically balances energy capture efficiency and equipment structural safety under different sea conditions through a real-time sensing-decision-execution feedback loop.

[0057] Four rotating wing power generation modules and a single solar sub-array are electrically connected in series to form a DC link. The output voltage of the wave energy power generation unit is superimposed on the photovoltaic voltage to achieve automatic voltage boosting. The high-voltage DC power after series connection is directly connected in parallel to the DC bus and connected to the inverter to be converted into AC power.

Claims

1. A power generation system for an underwater vehicle with unlimited range, characterized in that, The system comprises a main frame, wave energy capture units, solar power generation units, a transmission and power generation unit, and a control and energy storage unit. The main frame is constructed of corrosion-resistant steel, with a grid-like photovoltaic installation area at the top and reinforcing ribs and connecting seats for the rotating blades at the bottom. The wave energy capture unit includes rotating blade modules symmetrically arranged on both sides of the main frame. The rotating blades are made of fiberglass composite material and are connected to the main frame via hinge shafts to achieve 0-45 degree swinging. Each rotating blade surface is evenly distributed with four sets of impeller-type capture elements, and each set of impeller-type capture elements is directly connected to a permanent magnet synchronous generator via gears. The solar power generation unit is installed in the grid-like photovoltaic installation area at the top of the main frame, using matrix-layout flexible a-Si solar cells. The surface of the solar cells is coated with an organosilicon-modified coating, and the frame is made of nano-composite aluminum alloy. The transmission and power generation unit includes a linkage-gear transmission mechanism and an inverter. The reciprocating swing of the rotating blades is converted into continuous rotational motion of the generator rotor through the linkage-gear mechanism. The four rotating blade power generation modules are electrically connected in series with a single solar sub-array. A DC-DC link is formed and directly connected to the inverter. The control and energy storage unit includes a lithium battery pack, a multi-port converter, a water flow sensor, a light power sensor, and a wave energy power monitoring sensor. The sensors detect environmental parameters in real time and transmit them to the control unit. The control unit adjusts the output ratio of the two energy sources and controls the energy storage process through an algorithm. The impeller-type capture device includes a first guide impeller and a second guide impeller. Both the first and second guide impellers maintain an angle of 15 to 45 degrees with the plane. The impellers are distributed around the upper and lower surfaces of the rotating impeller and are directly connected to a permanent magnet synchronous generator through gears to convert mechanical motion into DC power. The lithium battery pack in the control and energy storage unit stores surplus energy to meet the power supply needs when there is no energy input for 3 days. The water flow sensor is embedded in the side of the rotating blade to detect the water flow speed and direction. The light power sensor and the wave energy power monitoring sensor output solar power generation signals and wave power generation signals in real time, respectively. The multi-port converter is connected to the output terminals of the solar power generation unit and the wave energy capture unit to adjust unstable power and output stable power. The control unit performs the following power supply mode switching based on the sensor detection results: when the solar power is greater than or equal to 500 milliwatts and the wave power is greater than or equal to 300 milliwatts, the system enters full power mode, and the solar power generation unit and the wave energy capture unit supply power to the vehicle in parallel and input excess energy into the lithium battery pack for storage; when the solar power is greater than or equal to 500 milliwatts and the wave power is less than 300 milliwatts, the control unit switches to solar single-phase power supply mode; when the solar power is less than 500 milliwatts and the wave power is greater than or equal to 300 milliwatts, the control unit switches to wave single-phase power supply mode; when the solar power is less than 500 milliwatts and the wave power is less than 300 milliwatts, the lithium battery pack serves as the main power source for supplying power to the vehicle.

2. The power generation system according to claim 1, characterized in that, The rotor is connected to the main frame via a hinge shaft, forming a swing range of 0°–45°. The swing range is optimally determined based on the wave statistical characteristics of the target sea area and the lift-drag characteristic curve of the hydrofoil, so that the rotor is always in the optimal angle of attack range under common wave height to period combinations, thereby maximizing the wave excitation torque and continuously capturing wave energy.

3. The power generation system according to claim 1, characterized in that, The optimal bandgap, depth, and curvature configuration of the flexible a-Si solar cell enables a photoelectric conversion efficiency of 59.8%. The silicone-modified coating on the surface of the solar cell, together with the nanocomposite aluminum alloy frame, provides resistance to salt spray environments.

4. The power generation system according to claim 1, characterized in that, The linkage-gear set in the transmission and power generation unit smoothly converts the reciprocating oscillation of the rotor into the continuous rotation of the generator to avoid mechanical impact. The rotor power generation module and the solar power generation unit are electrically connected in series to form a high-voltage DC power that is directly input to the inverter, eliminating the need for DC-DC conversion equipment and reducing power transmission loss.

5. The power generation system according to claim 1, characterized in that, When the water flow sensor detects that the water flow velocity is too high and turbulence is formed, the control unit drives the motor to control the impeller shaft to rotate in the opposite direction to reduce impeller impact; when the water flow sensor detects that the water flow velocity is within the normal range, the control unit adjusts the impeller attitude so that the impeller disk surface is always perpendicular to the water flow direction to achieve the best wave energy collection efficiency.

6. The power generation system according to claim 1, characterized in that, Four rotating wing power generation modules and a single solar sub-array are electrically connected in series to form a DC link. The output voltage of the wave energy power generation unit is superimposed on the photovoltaic voltage to achieve automatic voltage boosting. The high-voltage DC power after series connection is directly connected in parallel to the DC bus and connected to the inverter to be converted into AC power.

Images