An Elasticity-Enhanced Electromagnetic-Piezoelectric Hybrid Energy Harvesting Device and Method

Abstract

The present invention discloses an elastic enhanced electromagnetic - piezoelectric composite energy capture device and method, belonging to the technical field of energy harvesting. It includes a housing, sleeve mechanisms are arranged on both sides above the interior of the housing, a permanent magnet is installed between the two sleeve mechanisms, a U-shaped soft magnetic core installed on a jacket is arranged below the permanent magnet, a coil is sleeved on the U-shaped soft magnetic core, an elastic connecting piece connected to the bottom surface of the inner surface of the housing is arranged at the center of the bottom of the jacket, a number of piezoelectric sheets arranged at equal intervals are attached to both sides of the outer surface of the elastic connecting piece, and the piezoelectric sheets and the coil are connected to a power management module. First, the present invention increases the interaction movement between the magnet and the magnetic core by adding elastic devices, improves the power generation efficiency, and adds piezoelectric sheets to the elastic devices to make full use of this part of the energy, forming an electromagnetic - piezoelectric ocean energy capture device, which greatly improves the energy harvesting efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of energy harvesting, and in particular to an elastic enhanced electromagnetic-piezoelectric composite energy capture device and method. Background Art

[0002] The ocean contains a large amount of wave energy, which is huge and endless in scale. In recent years, more and more scientific researchers have focused on how to collect and utilize this part of energy. They have proposed ocean energy conversion devices to collect this energy and made self-powered detectors, sensors, etc. The collection and conversion efficiency of ocean energy is the key to technical applications. Currently, the energy conversion efficiency of many ocean energy harvesting technologies is still relatively low, which limits their commercialization and large-scale application. Traditional wave energy harvesting technologies are based on electromagnetic generators. Due to their expensive and bulky structures, susceptibility to corrosion, and insufficient energy conversion efficiency, especially at low frequencies, their development is restricted. Summary of the Invention

[0003] The purpose of the present invention is to provide an elastic enhanced electromagnetic-piezoelectric composite energy capture device and method. First, by adding elastic devices, more interaction movements occur between the magnet and the magnetic core, improving the power generation efficiency. Piezoelectric sheets are added to the elastic devices to make full use of this part of energy, forming an electromagnetic-piezoelectric ocean energy capture device and greatly improving the energy collection efficiency.

[0004] To achieve the above object, the present invention provides an elastic enhanced electromagnetic-piezoelectric composite energy capture device, including a housing. Sleeve mechanisms are arranged on both sides above the interior of the housing. A permanent magnet is installed between the two sleeve mechanisms. Below the permanent magnet, a U-shaped soft magnetic core installed on a jacket is provided. A coil is sleeved on the U-shaped soft magnetic core. At the center of the bottom of the jacket, an elastic connecting member connected to the bottom surface of the inner surface of the housing is provided. Piezoelectric sheets are attached to both sides of the outer surface of the elastic connecting member at equal intervals. The piezoelectric sheets and the coil are connected to a power management module.

[0005] Preferably, the power management module includes a battery and a rectifier. The battery is connected to the piezoelectric sheets and the coil through lines respectively, and a rectifier is installed on each line.

[0006] Preferably, springs are installed at the joints of the two sleeve mechanisms and the permanent magnet.

[0007] Preferably, the notch end faces of the permanent magnet and the U-shaped soft magnetic core are opposite, and the magnetic gap between the permanent magnet and the U-shaped soft magnetic core is maintained between 2-3 mm.

[0008] Preferably, the permanent magnet is made of a super strong magnet material.

[0009] Preferably, the U-shaped soft magnetic core is made of a high magnetic permeability material.

[0010] An elastic enhanced electromagnetic-piezoelectric composite energy capture method includes the following steps:

[0011] S1. Electromagnetic induction power generation: When the permanent magnet is externally excited, it can move back and forth left and right within the sleeve mechanism. The movement of the permanent magnet causes the number of magnetic field lines passing through the U-shaped soft magnetic core to change continuously, and the magnetic flux passing through the coil to change continuously. According to the principle of electromagnetic induction, an induced current and an induced electromotive force will be generated on the coil.

[0012] S2. Enhancing the electromagnetic power generation efficiency: When the permanent magnet moves, it attracts the U-shaped soft magnetic core, causing the elastic connecting piece to bend. When the bending reaches the limit (i.e., the elastic force is greater than the magnetic force and the Lorentz force), the U-shaped soft magnetic core will swing in the opposite direction.

[0013] When the natural frequency of the elastic connecting piece and the movement frequency of the permanent magnet reach a certain relationship, for each round trip of the permanent magnet, the U-shaped soft magnetic core makes two or more round trips. The frequency of the relative movement between the U-shaped soft magnetic core and the permanent magnet increases, and the electromagnetic power generation efficiency increases accordingly.

[0014] S3. Piezoelectric power generation: When the elastic connecting piece swings left and right, it will deform. The piezoelectric sheet attached to it is subjected to the pressure generated by this deformation. According to the direct piezoelectric effect, the piezoelectric sheet deforms under the action of force, causing the surface of the medium to be charged and generating a voltage.

[0015] S4. Energy storage: The alternating current generated by the electromagnetic induction power generation and the piezoelectric power generation is rectified into direct current by a rectifier and stored in a battery to achieve energy storage.

[0016] Therefore, the elastic enhanced electromagnetic-piezoelectric composite energy capture device and method with the above structure of the present invention have the following beneficial effects:

[0017] (1) By adding an elastic device, the present invention enables the coil and the magnet to have more relative movements, increasing the magnetic flux change rate. Especially when the frequency of the external excitation and the natural frequency of the spring device reach a certain resonance relationship, the power generation can be greatly improved. And the increase in the relative movement frequency between the magnetic core and the permanent magnet in the present invention further improves the electromagnetic power generation efficiency.

[0018] (2) By adding a piezoelectric sheet to the elastic device, when the spring sheet swings, the piezoelectric sheet generates a voltage under pressure, forming an electromagnetic-piezoelectric composite power generation mode, making full use of energy and greatly improving the energy collection efficiency.

[0019] (3) After the device of the present invention is arranged in a certain permutation and combination, it can collect low-frequency, multi-directional, and variable energy like ocean wave energy, adapt to the complex energy environment in nature, and expand the scope of energy collection.

[0020] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Description of the Drawings

[0021] Figure 1 is a schematic structural diagram of an elastic-enhanced electromagnetic-piezoelectric composite energy capture device and method of the present invention;

[0022] Figure 2 is a schematic diagram of the swinging movement process of the magnetic core and magnet of an elastic-enhanced electromagnetic-piezoelectric composite energy capture device and method of the present invention;

[0023] Figure 3 is a top view schematic diagram of a multi-directional elastic-enhanced ocean wave energy collector of an elastic-enhanced electromagnetic-piezoelectric composite energy capture device and method of the present invention;

[0024] Figure 4 is a front view schematic diagram of a multi-directional elastic-enhanced ocean wave energy collector of an elastic-enhanced electromagnetic-piezoelectric composite energy capture device and method of the present invention;

[0025] Figure 5 is a schematic diagram of an example of the open-circuit voltage output of electromagnetic power generation and piezoelectric power generation of an elastic-enhanced electromagnetic-piezoelectric composite energy capture device and method of the present invention;

[0026] Reference Numerals

[0027] 1. Permanent magnet, 2. Sleeve mechanism, 3. Spring, 4. U-shaped soft magnetic core, 5. Coil, 6. Piezoelectric sheet, 7. Elastic connecting piece, 8. Outer shell, 9. External excitation, 10. Power management module, 11. Rectifier, 12. Battery, 13. Relative movement, 14. Deformation, 15. Jacket. Specific Embodiments

[0028] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the ordinary meanings as understood by those of ordinary skill in the art to which the present invention pertains. The "first", "second" and similar terms used in the present invention do not denote any order, quantity or importance, but are only used to distinguish different components. Words such as "comprising" or "including" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. Words such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Upper", "lower", "left", "right", etc. are only used to indicate relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0030] Embodiment

[0031] Due to the fact that traditional electromagnetic ocean energy capture devices are relatively bulky in volume and have limited power generation, it is relatively difficult to apply them in low-frequency and micro fields. Piezoelectric power generation devices, on the other hand, have high conversion efficiency, especially perform excellently in low-frequency vibration energy harvesting, have strong environmental adaptability, and can harvest electrical energy from vibrations, pressure changes and other energies widely existing in the environment, which makes them have broad application potential in environmental energy harvesting. Therefore, the present invention proposes an elastic enhanced electromagnetic-piezoelectric composite energy capture device, as Figure 1-2 shown, which includes a housing 8. Sleeve mechanisms 2 are arranged on both sides above the interior of the housing 8. A permanent magnet 1 is installed between the two sleeve mechanisms 2. Below the permanent magnet 1, a U-shaped soft magnetic core 4 installed on a jacket 15 is provided. A coil 5 is sleeved on the U-shaped soft magnetic core 4. At the center of the bottom of the jacket 15, an elastic connecting member 7 connected to the bottom surface of the inner surface of the housing 8 is provided. Piezoelectric sheets 6 are attached to both sides of the outer surface of the elastic connecting member 7 at equal intervals. The piezoelectric sheets 6 and the coil 5 are connected to a power management module 10. In the present invention, the permanent magnet 1 is taken as a U-shaped permanent magnet as an example, and the permanent magnet 1 can also be cylindrical, arched, etc.

[0032] The power management module 10 includes a battery 12 and a rectifier 11. The battery 12 is connected to the piezoelectric sheets 6 and the coil 5 through lines respectively, and a rectifier 11 is installed on each line.

[0033] Springs 3 are installed at the connection points between the two sleeve mechanisms 2 and the permanent magnet 1.

[0034] The notch end face of the permanent magnet 1 faces the notch end face of the U-shaped soft magnetic core 4, and the magnetic gap between the permanent magnet 1 and the U-shaped soft magnetic core 4 is maintained between 2-3 mm.

[0035] The permanent magnet 1 is made of a super strong magnet material.

[0036] The U-shaped soft magnetic core 4 is made of a material with high magnetic permeability.

[0037] An elastic enhanced electromagnetic-piezoelectric composite energy harvesting method includes the following steps:

[0038] S1. Electromagnetic induction power generation: When the permanent magnet 1 is externally excited by the excitation 9, it can move back and forth left and right within the sleeve mechanism 2. The movement of the permanent magnet 1 causes the number of magnetic field lines passing through the U-shaped soft magnetic core 4 to change continuously, and the magnetic flux passing through the coil 5 changes continuously. According to the principle of electromagnetic induction, an induced current and an induced electromotive force will be generated on the coil 5.

[0039] S2. Enhancing the efficiency of electromagnetic power generation: When the permanent magnet 1 moves, it attracts the U-shaped soft magnetic core 4, causing the elastic connecting piece to bend. When the bending reaches the limit (i.e., the elastic force is greater than the magnetic force and the Lorentz force), the U-shaped soft magnetic core 4 will swing in the opposite direction.

[0040] When the natural frequency of the elastic connecting piece 7 and the movement frequency of the permanent magnet 1 reach a certain relationship, for each round trip of the permanent magnet 1, the U-shaped soft magnetic core 4 makes two or more round trips. The frequency of the relative movement 13 between the U-shaped soft magnetic core 4 and the permanent magnet 1 increases, and the electromagnetic power generation efficiency increases accordingly.

[0041] S3. Piezoelectric power generation: When the elastic connecting piece 7 swings left and right, it will deform 14. The piezoelectric sheet 6 attached to it is subjected to the pressure generated by this deformation. According to the direct piezoelectric effect, when the piezoelectric sheet 6 is subjected to a force, it deforms, causing the surface of the medium to become charged and generating a voltage.

[0042] S4. Energy storage: The alternating current generated by both the electromagnetic induction power generation and the piezoelectric power generation is rectified into direct current by the rectifier 11 and stored in the battery 12 to achieve energy storage.

[0043] In the present invention, by adding the elastic connecting piece 7, the coil 5 and the permanent magnet 1 make more relative movements, thereby increasing the rate of change of the magnetic flux. Especially when the frequency of the external excitation 9 and the natural frequency of the elastic connecting piece 7 reach a certain resonance relationship, the power generation amount can be greatly improved. The piezoelectric sheet 6 provided on the elastic connecting piece 7 is subjected to a certain pressure when the elastic connecting piece 7 swings, thereby generating a voltage. Through specific experiments, it has been confirmed that the present invention can generate a relatively high amount of electricity. As Figure 5 shown, under a harmonic excitation of 10 Hz and an amplitude of 2 - 3 mm, the electromagnetic power generation part and the piezoelectric power generation part of the present invention can respectively generate open-circuit peak values of 2.45 V and 1.09 V. By arranging and combining this device in a certain way, it is possible to collect low-frequency, multi-directional, and changing energy such as ocean wave energy.

[0044] As Figure 3-4As shown, a single energy harvester is combined. One is placed vertically in the middle, and the others are placed horizontally on the sides, one on each of the front, back, left, and right, forming a multi-directional elastic enhanced wave energy harvester. Considering the randomness of the size, frequency, and direction of waves in the ocean, this device can harvest the energy that causes the movement of the permanent magnet in all directions. Energy from any direction can cause the movement of the permanent magnet, and thus this part of the energy can be harvested, stored, and utilized. The arrangement and combination of the multi-directional elastic enhanced wave energy harvester can vary in quantity and position.

[0045] Therefore, the present invention adopts the above-mentioned elastic enhanced electromagnetic-piezoelectric composite energy capture device and method. First, by adding elastic devices, more interactive movements between the magnet and the magnetic core are generated, improving the power generation efficiency. Piezoelectric sheets are added to the elastic devices to make full use of this part of the energy, forming an electromagnetic-piezoelectric ocean energy capture device and greatly improving the energy harvesting efficiency.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An elastically enhanced electromagnetic-piezoelectric composite energy capture device, characterized in that: It comprises a shell, sleeve mechanisms are arranged on both sides of the upper part of the shell, a permanent magnet is installed between the two sleeve mechanisms, a U-shaped soft magnetic core installed on a jacket is arranged below the permanent magnet, a coil is sleeved on the U-shaped soft magnetic core, an elastic connector connected to the bottom of the inner surface of the shell is arranged at the center of the bottom of the jacket, a plurality of piezoelectric sheets arranged equidistantly are attached to both sides of the outer surface of the elastic connector, and the piezoelectric sheets and the coil are connected to a power management module; The power management module includes a battery and a rectifier, the battery is connected to the piezoelectric sheet and the coil respectively through lines, and the rectifier is installed on each line; Springs are installed at the connection points between the two sleeve mechanisms and the permanent magnets.

2. The elasticity-enhanced electromagnetic-piezoelectric composite energy capture device according to claim 1, characterized in that: The notched end face of the permanent magnet is opposite to the notched end face of the U-shaped soft magnetic core, and the magnetic gap between the permanent magnet and the U-shaped soft magnetic core is maintained between 2-3 mm.

3. The elasticity-enhanced electromagnetic-piezoelectric composite energy capture device according to claim 1, characterized in that: The permanent magnet is made of super strong magnet material.

4. The elasticity-enhanced electromagnetic-piezoelectric composite energy capture device according to claim 1, characterized in that: The U-shaped soft magnetic core is made of high magnetic permeability material.

5. An elasticity-enhanced electromagnetic-piezoelectric composite energy capture method, applied to an elasticity-enhanced electromagnetic-piezoelectric composite energy capture device as claimed in any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Electromagnetic induction power generation: When the permanent magnet is stimulated externally, it moves back and forth between the two sleeve mechanisms. The movement of the permanent magnet causes the number of magnetic field lines passing through the U-shaped soft magnetic core to change continuously, causing the magnetic flux passing through the coil to change continuously. According to the principle of electromagnetic induction, induced current and induced electromotive force will be generated in the coil; S2. Enhance the efficiency of electromagnetic power generation: the permanent magnet attracts the U-shaped soft magnetic core during movement to bend the elastic connector. When the bending reaches the limit, the U-shaped soft magnetic core will swing in the opposite direction. When the natural frequency of the elastic connector reaches a resonance relationship with the movement frequency of the permanent magnet, the permanent magnet goes back and forth once, and the U-shaped soft magnetic core goes back and forth more than twice, the frequency of relative movement between the U-shaped soft magnetic core and the permanent magnet increases, and the electromagnetic power generation efficiency increases accordingly; S3, piezoelectric power generation: the elastic connector will deform when it swings left and right, and the piezoelectric sheet attached to it will be subjected to the pressure generated by the deformation. According to the positive piezoelectric effect, the piezoelectric sheet will deform under the action of the force, causing the surface of the medium to be charged and generate voltage; S4. Energy storage: The alternating current generated by electromagnetic induction power generation and piezoelectric power generation is rectified into direct current through a rectifier and stored in a battery to achieve energy storage.

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