Electric field-magnetic field composite energy collection device

Abstract

The invention discloses an electric field-magnetic field composite energy acquisition device, and relates to the field of power transmission line induction energy acquisition. The device comprises a shell, an electric field energy taking device, a magnetic field energy taking device and a power management module. The electric field energy taking devices are installed on the two sides of the shell and sense an alternating current electric field around the power transmission line and output electric energy. The magnetic field energy taking device is installed in the shell and comprises a vibration assembly, a permanent magnet of the vibration assembly is driven by an alternating magnetic field of a power transmission line to generate periodic resonance motion, and electric energy is output. And the power management module integrates electric energy output by the electric field energy taking device and the magnetic field energy taking device and supplies power to a load. The energy collection device can collect energy from the alternating electric field and the alternating magnetic field around the high-voltage transmission line at the same time, energy conversion, output power stability and energy supply continuity are greatly improved, and reliable, long-term and self-powered energy support can be better provided for wireless sensing nodes.

Description

Technical Field

[0001] This invention relates to the field of inductive energy harvesting technology for power transmission lines, and more specifically, to a composite energy harvesting device for electric and magnetic fields. Background Technology

[0002] With the rapid development of smart grid technology, real-time online monitoring of transmission line operation status has become an important means to ensure the safe and stable operation of the power system. Distributed wireless sensor networks have broad application prospects in smart grid monitoring, enabling online data acquisition, fault early warning, and status assessment of transmission lines. However, most sensor nodes still rely on disposable batteries for power, which are limited by short battery life, frequent replacement and maintenance, and high labor costs, making it difficult to meet the needs of large-scale, long-term, and high-density deployment.

[0003] Alternating electric and magnetic fields are widely present around power transmission lines. These two sources are characterized by their wide spatial distribution, continuous and stable energy, and insensitivity to day / night cycles and weather conditions, making them highly promising environmental energy sources. Currently, various energy harvesting methods based on electric or magnetic fields have been proposed, such as electric field energy harvesters constructed using capacitive coupling and current transformer-based magnetic field harvesters based on the principle of electromagnetic induction. While these single-source harvesting schemes can achieve certain energy output under laboratory conditions, they generally suffer from the following technical drawbacks in practical engineering environments: (1) The structure is large in size and heavy in weight, making it difficult to integrate directly into the main body of the transmission line; (2) The installation is complicated and usually requires additional supports or insulation structures, which affects on-site construction and operation and maintenance; (3) The output power density is low, making it difficult to meet the long-term stable power supply requirements of the sensor; (4) It can only utilize a single field source and fails to utilize the energy redundancy and complementarity brought about by electric and magnetic fields in a coordinated manner. Summary of the Invention

[0004] In view of this, the present invention provides an electric field-magnetic field composite energy harvesting device to solve the problems of energy redundancy and complementarity and large structural volume caused by the inability of existing energy harvesting devices to utilize electric and magnetic fields in a coordinated manner.

[0005] To achieve the above objectives, the following solution is proposed: An electric field-magnetic field composite energy harvesting device includes: a housing, an electric field energy harvester, a magnetic field energy harvester, and a power management module; The electric field harvester is installed on both sides of the housing and is used to sense the AC electric field around the transmission line and output electrical energy. The magnetic field energy harvester is installed inside the housing and includes a vibration component. The permanent magnet of the vibration component is driven by the alternating magnetic field of the power transmission line to generate periodic resonant motion and output electrical energy. The power management module integrates the electrical energy output from the electric field harvester and the magnetic field harvester to supply power to the load. The power management module includes a rectifier, an energy storage and switching module, and a voltage regulator circuit. The electrical energy output from the electric field harvester and the magnetic field harvester is first rectified by the rectifier, then the energy is effectively controlled and allocated by the energy storage and switching module, and finally the output voltage is stabilized by the voltage regulator circuit.

[0006] Preferably, the housing comprises: an upper housing and a lower housing; The upper housing includes an outer edge and a first mounting groove; The lower housing includes a protrusion and a second mounting groove; The upper shell is connected to the lower shell via its outer edge, forming a sealed structure.

[0007] Preferably, the electric field energy harvester includes: a first metal electrode and a second metal electrode; The first metal electrode is fixed in the first mounting groove of the upper housing; The second metal electrode is installed in the second mounting slot.

[0008] Preferably, the electric field harvester is a single-electrode electric field harvester.

[0009] Preferably, the magnetic field harvester includes: a third metal electrode and a first elastic buffer layer; The first elastic buffer layer is fixed to the protrusion of the lower housing; The third metal electrode is fixed on the first elastic buffer layer.

[0010] Preferably, the vibration assembly includes: a second elastic buffer layer, a fourth metal electrode, and a friction film; The second elastic buffer layer, the fourth metal electrode, and the friction film are sequentially pasted, stacked, and fixed on the oscillator substrate from top to bottom; The friction film contacts and separates from the third metal electrode, generating electrical charge.

[0011] Preferably, the friction film is an electronegative polymer. Preferably, the electric field-magnetic field composite energy harvesting device further includes: a wireless sensing node module, used to collect the status data of the transmission line and transmit it wirelessly.

[0012] As can be seen from the above technical solution, the electric field-magnetic field composite energy harvesting device provided in this embodiment of the invention includes a housing, an electric field harvester, a magnetic field harvester, and a power management module. The electric field harvester is installed on both sides of the housing, sensing the alternating electric field around the transmission line and outputting electrical energy. The magnetic field harvester is installed inside the housing and includes a vibrating component. The permanent magnet of the vibrating component is driven by the alternating magnetic field of the transmission line to generate periodic resonant motion, outputting electrical energy. The power management module integrates the electrical energy output from the electric field harvester and the magnetic field harvester to power the load. The energy harvesting device of this invention can simultaneously harvest energy from the alternating electric field and alternating magnetic field around high-voltage transmission lines, greatly improving energy conversion efficiency, output power stability, and power supply continuity, and can better provide reliable, long-term, and self-powered energy support for wireless sensing nodes.

[0013] The electric field-magnetic field composite energy harvesting device of the present invention integrates an electric field energy harvester and a magnetic field energy harvester, achieving an integrated and miniaturized design in terms of structure. This greatly reduces the size of the energy harvesting device, making it more environmentally adaptable and better suited to the actual needs of the compact space and complex electromagnetic environment of high-voltage transmission lines. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0015] Figure 1 A functional design architecture diagram of an electric field-magnetic field composite energy harvesting device provided in an embodiment of the present invention; Figure 2 A schematic diagram of the structure of the electric field-magnetic field composite energy harvesting device provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the upper shell structure of the electric field-magnetic field composite energy harvesting device provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the lower shell structure of the electric field-magnetic field composite energy harvesting device provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the installation of the electric field harvester in the upper housing portion according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the installation of the electric field harvester in the lower housing portion according to an embodiment of the present invention; Figure 7 A schematic diagram of the vibration component structure of the electric field-magnetic field composite energy harvesting device provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of the vibratory component oscillator substrate structure provided in an embodiment of the present invention; Figure 9 A circuit diagram of a power management module provided for an embodiment of the present invention; Figure 10 Parasitic capacitance circuit diagram provided in the embodiments of the present invention; Figure 11 Another functional design architecture diagram of an electric field-magnetic field composite energy harvesting device provided in an embodiment of the present invention; Figure 12 A schematic diagram of the installation of another electric field harvester in the upper housing portion according to an embodiment of the present invention; Figure 13 The output voltage test curve of the dual-electrode electric field harvester provided in the embodiment of the present invention; Figure 14 The impedance power curve of the electric field energy harvester provided in the embodiment of the present invention; Figure 15 Voltage waveform diagrams at different transmission line frequencies provided in embodiments of the present invention; Figure 16 The impedance power curve of the magnetic field harvester provided in the embodiment of the present invention; Figure 17 This is a schematic diagram showing the experimental results of charging capacity under different energy harvesting methods provided in the embodiments of the present invention.

[0016] Explanation of reference numerals in the attached drawings: 1-Upper shell, 2-Lower shell, 3-Vibration assembly, 1-1-Outer edge of shell, 1-2-First mounting groove, 2-1-Protrusion, 2-2-Second mounting groove, 1-2-1-First metal electrode, 2-2-1-Second metal electrode, 2-1-1-Third metal electrode, 2-1-2-First elastic buffer layer, 3-1-Permanent magnet, 3-2-Oscillator substrate, 3-2-1-Second elastic buffer layer, 3-2-2-Fourth metal electrode, 3-2-3-Friction film. Detailed Implementation

[0017] The technical solutions of 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.

[0018] First, combined Figure 1-10 This invention provides an electric-magnetic field composite energy harvesting device, as described in an embodiment of the invention. Figure 1As shown, the electric-magnetic field composite energy harvesting device provided in this embodiment of the invention simultaneously harvests energy from the alternating electric field and alternating magnetic field surrounding high-voltage transmission lines. The harvesting device mainly includes a housing, an electric field harvester, a magnetic field harvester, and a power management module.

[0019] like Figures 2-3 As shown, the housing is a sealed structure composed of an upper housing 1 and a lower housing 2, used to fix and protect the internal vibration module and electrode structure. The upper housing 1 includes an outer edge 1-1 and a first mounting groove 1-2, as shown... Figure 4 As shown, the lower housing 2 includes a protrusion 2-1 and a second mounting groove 2-2. The upper housing 1 is fixedly connected to the lower housing 2 via the outer edge 1-1.

[0020] The electric field harvester is installed on both sides of the housing to sense the alternating electric field around the transmission line and output electrical energy. The electric field harvester can be a dual-electrode electric field harvester that senses the alternating electric field of the transmission line to collect electric field energy, or a single-electrode electric field harvester that is directly connected to the transmission line to collect electrical energy.

[0021] This invention uses a dual-electrode electric field harvester as an example. It harvests magnetic field energy using a magnetostrictive capacitive triboelectric motor transducer, and harvests electric field energy using a dual-electrode electric field harvester that eliminates the need for direct connection to a power transmission line. Finally, after packaging and power management, the harvested energy is used to power a load. The electric field harvester is located on both sides of the housing and consists of two metal electrodes. It induces a displacement current by capacitively coupling the AC electric field around the power transmission line. The electrode parameters (area and spacing) can be optimized to increase the coupling capacitance and enhance energy harvesting efficiency at low frequencies. Figure 5-6 As shown: an electric field energy harvester, including a first metal electrode 1-2-1 and a second metal electrode 2-2-1. The first metal electrode 1-2-1 is fixed in the first mounting groove 1-2 of the upper housing 1, and the second metal electrode 2-2-1 is installed in the second mounting groove 2-2.

[0022] The magnetic field harvester is installed inside the housing, such as Figure 6-7 As shown, the magnetic field energy harvester includes a third metal electrode 2-1-1, a first elastic buffer layer 2-1-2, and a vibration assembly 3 composed of an oscillator substrate 3-2 and a permanent magnet 3-1. The first elastic buffer layer 2-1-2 is fixed to the protrusion 2-1 of the lower housing 2, and the third metal electrode 2-1-1 is fixed to the first elastic buffer layer 2-1-2. The permanent magnet 3-1 is fixed to the oscillator substrate 3-2. The vibration assembly 3 is fixed in the cavity formed by the upper housing 1 and the lower housing 2.

[0023] like Figure 8As shown, the vibration component 3, from top to bottom, consists of a permanent magnet 3-1, an oscillator substrate 3-2, a second elastic buffer layer 3-2-1, a fourth metal electrode 3-2-2, and a friction film 3-2-3. The second elastic buffer layer 3-2-1, the fourth metal electrode 3-2-2, and the friction film 3-2-3 are sequentially adhered and stacked on the oscillator substrate 3-2 from top to bottom; that is, the second elastic buffer layer 3-2-1 is fixed to the oscillator substrate 3-2, the fourth metal electrode 3-2-2 is fixed to the second elastic buffer layer 3-2-1, and the friction film 3-2-3 is fixed to the fourth metal electrode 3-2-2. Vibration is driven by external excitation. Under the action of an alternating magnetic field, the permanent magnet 3-1 generates periodic resonant motion, achieving matching with the power frequency of the transmission line. This drives the friction film 3-2-3, which is fixed to the fourth metal electrode 3-2-2 at the bottom of the entire oscillator component, to vibrate. This vibration, along with the friction film 3-2-3, creates a vertical contact-separation structure with the third metal electrode 2-1-1, generating friction and outputting electrical energy.

[0024] The friction film 3-2-3 can be made of an electronegative polymer such as polytetrafluoroethylene (PTFE). The permanent magnet 3-1 is preferably of type N35 with a thickness ranging from 15 mm. The areas of the third metal electrode 2-1-1 and the fourth metal electrode 3-2-2 can be adjusted between 20-60 cm² to adapt to different electric field intensities. The oscillator substrate 3-2 can be made of lightweight materials to reduce the oscillator's mass. A lightweight structure not only reduces the initiation force of vibration, making it easier to capture low-frequency energy, but also reduces friction and wear during normal operation, thereby improving energy conversion efficiency. Lightweight materials for the oscillator substrate include carbon fiber, foam, plastics, and low-density polyethylene. In this embodiment, the oscillator 3-2 is made of polylactic acid.

[0025] The power management module integrates the electrical energy output from the electric field harvester and the magnetic field harvester to supply power to the load. For example... Figure 9 As shown, the power management module includes a rectifier, an energy storage and switching module, and a voltage regulator circuit. The electric field energy harvester is characterized using an equivalent circuit model, which consists of a voltage source and a variable capacitor connected in series to simulate the output characteristics of a triboelectric nanogenerator (TENG). The electrical energy harvested by the electric field energy harvester is first rectified by the rectifier, then effectively controlled and allocated by the energy storage and switching module, and finally stabilized by an LC filter (voltage regulator circuit). This circuit structure not only significantly improves energy transmission efficiency but also ensures the stability of the output voltage, providing a strong guarantee for the reliable operation of the energy harvesting system in practical applications. The structure and function of each module in this embodiment will be described below. (1) Rectifier The rectifier is located between the electric field harvester and the energy storage and switching module. The core of the rectifier is a full-wave bridge rectifier circuit, used to rectify the AC voltage signal generated by the electric field harvester into pulsating DC power. The rectifier circuit has symmetrical rectification capabilities for both positive and negative half-cycles to maximize power conversion efficiency. The rectifier bridge circuit preferably uses high-voltage, low-leakage-current electronic components to accommodate the high amplitude and wide frequency response characteristics of the input signal.

[0026] (2) Energy storage and switching module The energy storage module includes an energy storage capacitor whose capacitance is configured to match the inherent output characteristics of the electric field energy harvester to achieve efficient charge storage. A switching module is coupled to the energy storage module and can use a discharge tube or electronic switch to control the circuit's on / off state. Its function is to isolate the circuit from the preceding energy stage and, through the regulation of the switching state, maximize the extraction of energy from the preceding stage.

[0027] One specific implementation of the switching module is as follows: a silicon controlled thyristor (SCR) is used as the switching electron tube. A Zener diode is connected in parallel with the SCR. The positive terminal of the Zener diode is connected to the gate of the SCR, and its negative terminal is connected to the cathode of the SCR. By utilizing the breakdown effect of the Zener diode, a trigger signal is provided to the gate of the SCR, thereby achieving pulse switching control.

[0028] (3) Voltage stabilizing module The voltage regulator module is connected after the switching module and includes an LC filter circuit and a voltage conversion chip. This voltage regulator module acts as an energy converter, transforming the high-voltage, low-current electrical energy released by the energy storage module into low-voltage, high-current electrical energy, and then powering the downstream load devices.

[0029] The energy harvesting device of this invention uses an external alternating magnetic field to drive a magnet to vibrate vertically, achieving contact-separation friction between electrodes, thereby outputting charge. Simultaneously, metal electrodes positioned on both sides of the housing sense the alternating electric field of the transmission line, and through... Figure 10 The parasitic capacitance shown generates displacement current and outputs energy. C ce C is the equivalent capacitance between the first metal electrode 1-2-1 and the transmission line; EEH C is the equivalent capacitance between the first metal electrode 1-2-1 and the second metal electrode 2-2-1; eg This is the parasitic capacitance between the second metal electrode 2-2-1 and GND ground.

[0030] The two power sources are integrated through an integrated power management module to power the load.

[0031] The energy harvesting device has an overall volume of 5.5 cm × 8.5 cm × 1.0 cm and a weight of only 32 g. Its small size, compact structure, and high integration make it suitable for long-term deployment on transmission line components (such as insulators and crossarms).

[0032] Furthermore, the electric-magnetic field composite energy harvesting device of this embodiment can also integrate a wireless sensor node module for collecting and wirelessly transmitting the status data of the transmission line. By integrating the wireless sensor node module with the energy harvester, status data such as temperature and current of the transmission line can be collected and wirelessly transmitted.

[0033] Next, this invention describes an electric-magnetic field composite energy harvesting device for a single-electrode electric field harvester. The energy harvesting device is basically the same in structure and principle as the energy harvesting device in the aforementioned embodiments, such as... Figure 11 As shown, the difference lies in the fact that this embodiment of the invention adopts a single-electrode form, directly connecting the metal electrode to the power transmission line via a wire, replacing the bipolar plate suspension structure in Embodiment 1. Therefore, only the second metal electrode 2-2-1 of the lower housing 2 is retained, the first elastic buffer layer 2-1-2 is fixed on the protrusion 2-1 of the lower housing 2, and the metal electrode is fixed on the second mounting groove 2-2. At this time, since another electrode is not needed, therefore, as Figure 12 As shown, the upper shell does not need to have the first mounting groove 1-2 at this time, only the outer edge of the shell 1-1 is provided.

[0034] The energy harvesting device of this invention harvests magnetic field energy through a magnetic field harvester, harvests electric field energy through a single-electrode electric field harvester directly connected to a power transmission line, and finally supplies power to the load after encapsulation and power management.

[0035] This invention uses the electric-magnetic field composite energy harvesting device of the dual-electrode electric field harvester in the aforementioned embodiment as an example to verify the feasibility of the electric-magnetic field composite energy harvesting device. The verification results are as follows: like Figure 13 As shown, the dual-electrode electric field harvester can stabilize the output voltage.

[0036] like Figure 14 As shown, under a 10 kV transmission line environment, the impedance power curve of the electric field harvester shows that the maximum power of the dual-electrode electric field harvester can reach 4.6 milliwatts.

[0037] like Figure 15 As shown, the voltage fluctuation of the stable response output by the electric field-magnetic field composite energy harvesting device in this embodiment of the invention is small under different transmission line frequencies.

[0038] like Figure 16 As shown, the magnetic field energy harvester of this embodiment of the invention has a maximum power of 1.2 milliwatts under a 500A transmission line (Current) environment.

[0039] like Figure 17 As shown, the effectiveness of the combined energy harvesting was verified through a charging capacity experiment. The combined energy harvesting of electric and magnetic fields (EMF-EH) is more effective than either magnetic field or electric field energy harvesting alone.

[0040] In summary, the electric field-magnetic field composite energy harvesting device of the present invention has significant advantages in terms of structural design, energy conversion efficiency and system integration, and is particularly suitable for providing stable and long-term autonomous power supply support for distributed sensing devices in high-voltage transmission lines.

[0041] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0042] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0043] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A composite electric-magnetic field energy harvesting device, characterized in that, include: Housing, electric field harvester, magnetic field harvester, and power management module; The electric field harvester is installed on both sides of the housing and is used to sense the AC electric field around the transmission line and output electrical energy. The magnetic field energy harvester is installed inside the housing and includes a vibration component. The permanent magnet of the vibration component is driven by the alternating magnetic field of the power transmission line to generate periodic resonant motion and output electrical energy. The power management module integrates the electrical energy output from the electric field harvester and the magnetic field harvester to supply power to the load; The power management module includes a rectifier, an energy storage and switching module, and a voltage regulator circuit. The electrical energy output from the electric field harvester and the magnetic field harvester is first rectified by the rectifier, then the energy is effectively controlled and allocated by the energy storage and switching module, and finally the output voltage is stabilized by the voltage regulator circuit.

2. The electric field-magnetic field composite energy harvesting device according to claim 1, characterized in that, The housing includes: an upper housing and a lower housing; The upper housing includes an outer edge and a first mounting groove; The lower housing includes a protrusion and a second mounting groove; The upper shell is connected to the lower shell via its outer edge, forming a sealed structure.

3. The electric field-magnetic field composite energy harvesting device according to claim 2, characterized in that, The electric field energy harvester includes: a first metal electrode and a second metal electrode; The first metal electrode is fixed in the first mounting groove of the upper housing; The second metal electrode is installed in the second mounting slot.

4. The electric field-magnetic field composite energy harvesting device according to claim 2, characterized in that, The electric field harvester is a single-electrode electric field harvester.

5. The electric field-magnetic field composite energy harvesting device according to claim 2, characterized in that, The magnetic field harvester includes: a third metal electrode and a first elastic buffer layer; The first elastic buffer layer is fixed to the protrusion of the lower housing; The third metal electrode is fixed on the first elastic buffer layer.

6. The electric field-magnetic field composite energy harvesting device according to claim 5, characterized in that, The vibration assembly includes: a second elastic buffer layer, a fourth metal electrode, and a friction film; The second elastic buffer layer, the fourth metal electrode, and the friction film are sequentially pasted, stacked, and fixed on the oscillator substrate from top to bottom; The friction film contacts and separates from the third metal electrode, generating electrical charge.

7. The electric field-magnetic field composite energy harvesting device according to claim 6, characterized in that, The friction film is an electronegative polymer.

8. The electric field-magnetic field composite energy harvesting device according to claim 1, characterized in that, The electric field-magnetic field composite energy harvesting device further includes: a wireless sensing node module, used to collect the status data of the transmission line and transmit it wirelessly.

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