Energy harvesting system with regulated oscillation

Abstract

The present invention relates to an energy harvesting system for harvesting usable energy from fluid movements such as wind and currents. With the invention, torque and power output can be achieved with regular and high efficiency under the influence of flow with irregular velocity. For this purpose, an energy harvesting system has been developed which enables both the control of the oscillation characteristics and the realisation of the oscillation according to a certain pattern. Methods for controlling the energy harvesting system are also described.

Description

[0001] ENERGY HARVESTING SYSTEM WITH REGULATED OSCILLATION

[0002] Technical Field

[0003] The present invention relates to an energy harvesting system for harvesting usable energy from fluid movements such as wind and currents.

[0004] Prior Art

[0005] Renewable energy is energy obtained from sources that can be renewed faster than the rate of depletion. These resources provide limitation of environmental impacts arising from energy production. Especially compared to fossil energy sources, it can provide great advantages in terms of the emission of harmful gases.

[0006] Water (hydraulic), wind, solar (solar, photovoltaic), natural hot water and water vapour (geothermal), biomass, biogas, wave power, tidal energy and tidal energy, hydrogen are the main renewable energy sources.

[0007] With the development of technology and research on the environmental damage of energy obtained from fossil fuels, the tendency towards renewable energy sources has increased.

[0008] Various developments for obtaining renewable energy sources are known in the art.

[0009] Today, despite the high installation and operating costs of wind energy systems, sufficient efficiency to make them applicable can be achieved by increasing the wind sweep area dimensions (blade length) and tower height. However, the moments acting on the structure also increase with the pallet length and tower height. Due to the centrifugal effect especially on the blades and the high linear velocities reached by the blade endpoints, the turbine may need to be braked under fast wind effect. Turbines cannot be operated efficiently with slow or irregular winds. The narrow wind speed ranges that will provide efficient operating conditions cause the selection of the application area to be determined by long statistical studies. These problems related to wind turbines are also valid for systems based on the current of water bodies. In the document numbered EP3665386A1, a system is described which enables a regular energy output to be obtained from wind and current with irregular speed and direction. The system comprises multiple blades that oscillate under the influence of wind and gravity, and fasteners that transfer the angular motion of the blades to a shaft in one direction, allowing the shaft to be rotated regularly with the irregular oscillation of the blades.

[0010] In the document numbered TR201821246 A2, a system is described in which the oscillation character of the blades can be regulated in a system in which the movement of the blades oscillating under the effect of wind and gravity is transferred to a shaft. This system allows the oscillation character to be regulated by transferring a liquid in tanks located on the blade to tanks at different positions.

[0011] In the document numbered TR202014458A2, a system is disclosed having a connection arrangement which enables the bidirectional motion of the blades oscillating under the influence of wind and gravity to be converted into unidirectional motion of a main shaft. The motion of the sub-shafts to which the blades are connected is harvested by means of links connecting the sub-shafts to the main shaft at two points and enabling the motion of the subshaft in opposite directions to each other to be transmitted in a single direction.

[0012] In the application numbered TR2023 / 011403, a system is disclosed comprising blades that oscillate under the influence of wind and a recalling force provided by a recalling mechanism instead of a gravitational or buoyancy force. In addition to the recall mechanism, a collector mechanism for harvesting energy from the oscillation of the blades is also disclosed.

[0013] Objects of the Invention

[0014] The object of the present invention is to develop an energy harvesting system for converting the variable kinetic energy of moving fluids into usable forms of energy.

[0015] Another object of the present invention is the development of an energy harvesting system capable of operating over a wide velocity range or under the influence of flow with irregular velocity.

[0016] A further object of the present invention is the development of an energy harvesting system which, in a structure comprising a plurality of blades, prevents the irregular torque output of the blades, which leads to efficiency losses due to the blades moving together, and which is higher than can be utilised by the alternator used.

[0017] Detailed Description of the Invention

[0018] The energy harvesting system according to the invention, which converts the kinetic energy of moving fluids into usable forms of energy, essentially comprises at least one shaft, at least one blade connected to the shaft and capable of angular movement around the point where it is connected to the shaft under the influence of the fluid acting on its surface, at least one collector shaft parallel to each shaft, connected to the shafts by at least two connection points that transfer the rotational movement in opposite directions, providing energy harvesting from the angular movement of the blades

[0019] The collector shaft may be connected directly to a load to utilise the harvested energy, or preferably there is an alternator connected to the collector shaft which converts the energy into electrical energy. There may also be a flywheel arrangement positioned before the alternator for regulating the output of the collector shaft.

[0020] While the blades are driven by the fluid motion, they oscillate due to the buoyancy force acting on them, which depends on the weight or the medium in which they are used. The oscillation of the blades can be harvested in a usable form by means of the collector shaft.

[0021] Preferably, the energy harvesting system may also comprise at least one recall mechanism associated with each blade to support the weight and lift force generating the recall force and exerting a force in the opposite direction to the moving blade due to the fluid effect. The recoil mechanism consists of a flexible element such as air / gas spring, metal spring, polymer spring, silicone spring. The recall mechanism is preferably adjustable. For this, the stiffness and / or effective length of the flexible element can be adjusted. Thus, the response of the recall mechanism to the oscillation of the blade can be regulated. The stiffness and / or the effective length of the flexible element can be controlled mechanically or electromechanically, by means of wired or wirelessly transmitted signals. The energy harvesting system may further comprise at least one track on the blade extending along the blade from a region of the blade close to the shaft to the free end, at least one weight and / or at least one lifting material having a density lower than the density of the fluid displaced along the track, and at least one drive mechanism driving the weight and / or lifting material along the track. By changing the position of the weight and / or lifting material along the track, the distance of the centre of gravity of the blade to the shaft can be changed. Thus, by controlling the oscillation characteristics of the blade, the desired oscillation pattern and accordingly regular torque output can be provided despite the changing fluid velocity.

[0022] The track may be a structure which defines a direction along which the weight and / or lifting material is moved, such as a rail, a ball screw, a wire, a belt. The drive mechanism also enables the movement of the weight and / or lifting material along this track. The drive mechanism can provide the movement of the weight and / or lifting material directly or indirectly by moving the track, as in examples such as ball screws and belts.

[0023] The drive mechanisms can be operated by all kinds of data processing techniques, including artificial intelligence techniques. For this, data from all sensors associated with the energy harvesting system and its components, including Internet of Things (loT) techniques, are processed and the required weight and / or lifting material positions are determined.

[0024] The lifting material may consist of a flexible body, such as a balloon, or a rigid body, such as a tank, and a substance with a lower density than the fluid, for example helium if the fluid is air.

[0025] The energy harvesting system may further comprise at least one brake mechanism acting on each blade. The braking mechanism may have a structure, such as a lining capable of pressing on a bearing or hub structure located at the point where the blade is connected to the shaft or at the point where the shaft is connected to the collector shaft, a structure, such as a lining, capable of pressing on the shaft, located on a projection surrounding the shaft and located on the trajectory of the blade, and capable of directly contacting the blade. The brake mechanism may be pneumatic, electromechanical or otherwise operated.

[0026] In an energy harvesting system according to the invention comprising more than one blade, in the case of co- or near-phase movement of the oscillating blades, torque may be generated above the load (alternator resistance) created by the alternator, resulting in loss of efficiency. In order to prevent this, the co-phase or near-phase movement of the blades is prevented by an oscillation control method comprising the process steps receiving information about a targeted oscillation pattern consisting of the number of blade rows and the angular position of the blades as a periodic function of time, measuring of the angular positions of the blades instantaneously, calculating the difference of the measured angular positions from the target angular position according to the oscillation pattern information, if it is determined that the difference calculated for a blade exceeds a first threshold value, operating at least one brake mechanism acting on that blade in such a way as to ensure that the blade oscillates in accordance with the oscillation pattern

[0027] The brake mechanism ensures compliance with the desired oscillation pattern for efficiency by acting on the blades that prevent the targeted oscillation pattern due to the high flow rate.

[0028] The braking mechanisms preferably act on the blades when the blades are at the end points of the oscillation relative to the position, i.e. when they are at their slowest. For this purpose, the angular velocity of the blades is also determined and the brake mechanism is activated when this angular velocity falls below a second threshold value. The second threshold value is determined to take the lowest value suitable for the measurement accuracy and the operating speed of the brake mechanism so that the brake mechanism can be operated as close as possible to the moment when the blade stops. By operating the brake mechanisms when the blades are slowest, the brake mechanisms can be operated with minimum energy consumption and the loads and waste heat generated on the energy harvesting system due to the operation of the brake mechanisms can be kept at a limited level. Angular velocities can be measured instantaneously or calculated instantaneously using angular position information.

[0029] The oscillation pattern is determined as a time-periodic function, e.g. a sine curve, with different phases according to the number of rows of blades in order to minimise the number of blades in phase or in close phase on a shaft with more than one shaft at any one time. In order to ensure not only efficient energy harvesting but also the proper distribution of the loads on the energy harvesting system, the oscillation pattern can also be defined as a sine curve, which is periodic with respect to both time and position, for example, the length of the shaft is equal to one or more periods. In an embodiment of the invention, the brake mechanisms are not operated continuously, but are operated when the standard deviation of the angular position of the blades is determined to be below a third threshold value.

[0030] In an embodiment of the invention, in order to protect the energy harvesting system from loads due to high flow rate, the brake mechanisms are not operated when the flow rate is above a fourth threshold value.

[0031] The angular positions of the blades and the angular velocities of the blades can be measured by sensors associated with each blade on the energy harvesting system, by using image processing techniques on data from a camera providing a snapshot of the blades, by calculating acceleration data from inertial sensors on the blades, or otherwise. Flow velocity can be measured by sensors on the energy harvesting system. Data can be collected instantaneously from a large number of sensors in accordance with the techniques of Internet of Things.

[0032] Within the scope of the oscillation control method, the data provided from all sensors associated with the energy harvesting system and its components can be processed by all kinds of data processing techniques, including artificial intelligence techniques, and the condition of the blades can be determined and the brake mechanisms can be controlled. In an energy harvesting system comprising adjustable recall mechanisms according to the invention, the brake mechanisms and the recall mechanisms can be controlled in such a way as to ensure the movement of the blades in accordance with the oscillation pattern by utilising all kinds of data processing techniques, including artificial intelligence techniques. The oscillation pattern and threshold values may have default values, or may be the outputs of functions with default coefficients, or may be determined by artificial intelligence techniques.

[0033] Within the scope of the invention, various data including image processing outputs, flow speed and direction, generated torque and power, blade angular position information can be utilised. The collected data can be used to control the weight and / or lifting material positions, recall mechanism response and braking to maintain and regulate the oscillation by means of a software. Thus, regular and highly efficient energy harvesting can be realised.

Claims

CLAIMS1. An energy harvesting system for converting the kinetic energy of moving fluids into usable energy forms comprising at least one shaft, at least one blade connected to the shaft and capable of angular movement around the point where it is connected to the shaft under the influence of the fluid acting on its surface, at least one collector shaft parallel to each shaft, connected to the shafts by at least two connection points that transfer the rotational movement in opposite directions, providing energy harvesting from the angular movement of the blades characterized in that in order to control the oscillation characteristics of the blade, it further comprises at least one track on the blade extending along a direction from the near-shaft region of the blade to the free end of the blade, at least one weight and / or at least one lifting material with a density lower than the fluid density that can be displaced on this track, at least one drive mechanism that moves the weight and / or lifting material along the track.

2. An energy harvesting system according to claim 1 characterized in that the track is a rail, a ball screw, a wire or a belt.

3. An energy harvesting system according to claim 1 characterized in that it comprises at least one restoring mechanism associated with each blade and exerting a force in the opposite direction to the moving blade under the action of the fluid.

4. An energy harvesting system for converting the kinetic energy of moving fluids into usable energy forms comprising at least one shaft, more than one blade connected to the shaft and capable of angular movement around the point where it is connected to the shaft under the influence of the fluid acting on its surface,at least one collector shaft parallel to each shaft, connected to the shafts by at least two connection points that transfer the rotational movement in opposite directions, providing energy harvesting from the angular movement of the blades an alternator connected to the collector shaft characterized in that in it further comprises at least one brake mechanism acting on each blade.

5. An energy harvesting system according to claim 4 characterized in that the braking mechanisms have a structure such as a clutch capable of pressing a bearing or hub structure located at the point where the blade is connected to the shaft or at the point where the shaft is connected to the collector shaft, a structure such as a clutch capable of pressing the shaft, a structure located on a projection surrounding the shaft and located on the trajectory of the blade, and a structure capable of direct contact with the blade.

6. An energy harvesting system according to claim 4 characterized in that it comprises at least one restoring mechanism associated with each blade and exerting a force in the opposite direction to the moving blade under the action of the fluid.

7. A method for controlling the oscillations of the blades in an energy harvesting system according to claims 4, 5 or 6, characterized by comprising the process steps receiving information about a targeted oscillation pattern consisting of the number of blade rows and the angular position of the blades as a periodic function of time, measuring of the angular positions of the blades instantaneously, calculating the difference of the measured angular positions from the target angular position according to the oscillation pattern information, if it is determined that the difference calculated for a blade exceeds a first threshold value, operating at least one brake mechanism acting on that blade in such a way as to ensure that the blade oscillates in accordance with the oscillation pattern.

8. A method according to claim 7 characterized by determining the angular velocities of the blades and activating the relevant brake mechanism when this angular velocity falls below a second threshold value.

9. A method according to claim 8 characterized by measuring of the angular velocities of the blades instantaneously.

10. A method according to claim 8 characterized by calculating the angular velocities of the blades instantaneously using angular position information.

11. A method according to claim 7 characterized by the oscillation pattern being in the form of a periodic function according to time with different phases according to the number of blade rows.

12. A method according to claim 11 characterized by the oscillation pattern being in the form of a periodic function according to both time and position.

13. A method according to claim 7 characterized by operating the braking mechanisms if it is determined that the standard deviation of the angular position of the blades is below a third threshold value.

14. A method according to claim 7 characterized by not operating the brake mechanisms if the flow velocity is above a fourth threshold value.

15. A method according to claim 7 characterized by using image processing outputs, flow velocity and direction, generated torque and power, blade angular position information.