A high-voltage direct-current transmission line temperature difference energy extraction device and power generation assembly based on thermomagnetic drive

Abstract

This application discloses a thermomagnetic driven high-voltage direct current (HVDC) transmission line temperature difference energy harvesting device and power generation component. The solution constructs a thermomagnetic driven energy harvesting structure consisting of a thermomagnetic rotor, a thermally conductive insulating coupling part, a heat dissipation unit, and a magnetic field biasing component. This structure converts the Joule heat generated during the operation of the HVDC transmission line and its steady-state weak temperature difference with the environment into a circumferential temperature gradient of the thermomagnetic rotor. Furthermore, it utilizes the temperature-sensitive characteristics of the thermomagnetic material to generate a difference in magnetic response capability. Under the synergistic effect with the bias magnetic field, an unbalanced magnetic torque is formed to drive the rotor to rotate. Finally, this is converted into electrical energy output through a driven power generation structure. Thus, without relying on alternating magnetic fields or external mechanical excitation, this solution achieves efficient, continuous, and maintenance-free utilization of low-grade thermal energy in the steady electromagnetic environment of HVDC transmission lines, providing a stable and reliable self-powered solution for online monitoring equipment of transmission lines.

Description

Technical Field

[0001] This application belongs to the field of power supply technology for power transmission and distribution line monitoring equipment, specifically relating to a thermomagnetic driven high voltage DC transmission line temperature difference energy harvesting device and power generation component. Background Technology

[0002] With the widespread application of high-voltage direct current (HVDC) transmission lines in cross-regional energy transmission, new energy export, and offshore wind power grid connection, the demand for online monitoring of parameters such as conductor temperature, icing, galloping, sag, and insulation status is constantly increasing. Related monitoring equipment typically operates long-term in the field, at high altitudes, and in complex climatic environments, placing high demands on the stability, continuity, and low maintenance of its power supply system.

[0003] Currently, the self-powering methods for online monitoring equipment of transmission lines mainly include solar energy harvesting, wind energy harvesting, electric field coupling energy harvesting, and magnetic field induction energy harvesting. However, the above technical routes have significant shortcomings in the high-voltage direct current (HVDC) transmission scenario: solar power supply is greatly affected by day and night, cloudy and rainy weather, and dust accumulation, resulting in insufficient stability and continuity; wind power supply depends on ambient wind speed and direction, leading to large output fluctuations; and traditional magnetic field induction energy harvesting and electric field coupling energy harvesting both rely on the periodic alternating electromagnetic field in AC transmission lines, making them difficult to directly apply to the HVDC transmission line environment, which is characterized by a steady electric field and a steady magnetic field.

[0004] In response to the temperature rise caused by the Joule heating effect during long-term current-carrying operation of high-voltage direct current (HVDC) transmission lines, the surface temperature of the lines is typically higher than the ambient temperature, creating a persistent weak temperature difference between the lines and the environment. This temperature difference energy source is characterized by its continuous and widespread distribution, providing a new direction for self-powered technologies. However, existing thermoelectric and pyroelectric conversion technologies have limited output capabilities under conditions of weak temperature differences and gradual temperature changes, making it difficult to meet the long-term stable power supply requirements of online monitoring equipment.

[0005] Therefore, in order to address the aforementioned technical deficiencies, there is an urgent need to design and develop a thermomagnetic driven high-voltage direct current transmission line temperature difference energy harvesting device and power generation components. Summary of the Invention

[0006] To overcome the shortcomings and difficulties of the existing technology, the purpose of this application is to provide a thermomagnetic driven high-voltage direct current transmission line temperature difference energy harvesting device and power generation component, so as to solve the problem that the existing self-powered technology has poor applicability in high-voltage direct current transmission scenarios and is difficult to effectively utilize the weak temperature difference energy between the conductor and the environment.

[0007] The first objective of this application is to provide a thermomagnetic driven high-voltage direct current transmission line temperature difference energy harvesting device; the second objective of this application is to provide a thermomagnetic power generation component for the high-voltage direct current transmission line temperature difference energy harvesting device; and the third objective of this application is to provide a high-voltage direct current transmission line self-power supply method based on the aforementioned device.

[0008] The first objective of this application is achieved by the device comprising at least one thermomagnetic rotor made of a material having magnetic response characteristics that vary with temperature (i.e., thermomagnetic effect).

[0009] A thermally conductive and insulating coupling part is disposed between the DC transmission line and the thermomagnetic rotor and is used to conduct the heat of the line to the heat source side area of ​​the thermomagnetic rotor while achieving electrical insulation.

[0010] A heat dissipation unit is disposed on the side of the thermomagnetic rotor away from the wire and is used to dissipate heat from the cold source side region of the thermomagnetic rotor to the environment and to form a circumferential temperature gradient on the thermomagnetic rotor.

[0011] A magnetic field biasing element, disposed adjacent to the thermomagnetic rotor, provides a bias magnetic field. The circumferential temperature gradient causes a high-temperature weak magnetic response region and a low-temperature strong magnetic response region to be generated on the thermomagnetic rotor. Under the action of the bias magnetic field, the magnetic attraction force on the low-temperature strong magnetic response region is greater than that on the high-temperature weak magnetic response region. Furthermore, due to the predetermined relative positions of the thermally conductive insulating coupling part and the heat dissipation unit in the circumferential direction, the magnetic attraction force forms an asymmetrical distribution on the thermomagnetic rotor, thereby generating an unbalanced magnetic torque to drive its rotation.

[0012] A driven power generation structure is mechanically coupled to the thermomagnetic rotor and is used to convert the rotational mechanical energy of the thermomagnetic rotor into electrical energy output.

[0013] Furthermore, the thermomagnetic rotor includes at least two arranged along the same axis of rotation;

[0014] The magnetic field biasing element is configured to make the driving torque generated by each thermomagnetic rotor have the same direction, so as to jointly drive the shaft to rotate.

[0015] Furthermore, the driven power generation structure includes an electromagnetic power generation unit and / or a triboelectric power generation unit; wherein, the electromagnetic power generation unit includes a power generation magnetic component that rotates with the thermomagnetic rotor and a coil that is fixed relative to the device housing, and induced electrical energy is generated through the relative motion between the power generation magnetic component and the coil;

[0016] The triboelectric power generation unit includes a first friction material layer that rotates with the thermomagnetic rotor and a second friction material layer that is fixed relative to the outer casing of the device. Triboelectric energy is generated through periodic contact separation or sliding friction between the first friction material layer and the second friction material layer.

[0017] Furthermore, the electromagnetic power generation unit and the triboelectric power generation unit are integrated into a composite power generation unit; the composite power generation unit includes a rotor and a stator coaxially arranged with the thermomagnetic rotor, the rotor is provided with a power generation magnetic component and a first friction material, and the stator is provided with a coil and an electrode layer.

[0018] Furthermore, the thermally conductive and insulating coupling part is selected from an arc-shaped thermally conductive pad, a semi-enclosed thermally conductive cover, or a thermally conductive shoe, and its material is selected from aluminum nitride ceramic, alumina ceramic, boron nitride composite material, mica-based material, or thermally conductive and insulating silicone.

[0019] Furthermore, the heat dissipation unit is selected from heat dissipation fins, heat pipes, heat-conducting blocks, or radiative heat dissipation layers.

[0020] Furthermore, the device also includes an energy management unit;

[0021] The energy management unit is electrically connected to the output terminal of the driven power generation structure and is used to rectify, store, and stabilize the electrical energy to output a stable DC voltage.

[0022] Preferably, the thermomagnetic material has a Curie temperature Tc. When the local temperature of the thermomagnetic rotor is close to or below Tc, its magnetization, permeability, and / or susceptibility are at a high level, exhibiting a strong magnetic response. When the local temperature of the thermomagnetic rotor is far from and above Tc, its magnetization, permeability, and / or susceptibility decrease significantly, exhibiting a weak magnetic response. The circumferential temperature gradient causes the thermomagnetic rotor to simultaneously include the high-temperature weak magnetic response region and the low-temperature strong magnetic response region in the circumferential direction.

[0023] Furthermore, the thermomagnetic rotor is made of at least one thermomagnetic material selected from the group consisting of gadolinium (Gd), Gd-based alloys, La-Fe-Si-H alloys, MnFePAs alloys, NiMn-based Heusler alloys, or composites thereof.

[0024] The second objective of this application is achieved as follows: the thermomagnetic generator includes at least one thermomagnetic rotor made of a material whose magnetic response characteristics change with temperature, and is configured to form a temperature gradient in its circumferential direction under the combined action of an external heat source and a cold source.

[0025] A magnetic field biasing element, disposed adjacent to the thermomagnetic rotor and used in conjunction with the temperature gradient, generates an unbalanced magnetic torque on the thermomagnetic rotor to drive its rotation; and...

[0026] A driven power generation structure is mechanically coupled to the thermomagnetic rotor and is used to convert the rotational mechanical energy of the thermomagnetic rotor into electrical energy output.

[0027] Furthermore, the driven power generation structure includes an electromagnetic power generation unit and / or a triboelectric power generation unit.

[0028] The third objective of this application is achieved by the method comprising the following steps:

[0029] By utilizing the Joule heat of the DC transmission line and its temperature difference with the environment, a circumferential temperature gradient is established on at least one thermomagnetic rotor.

[0030] The combined effect of the bias magnetic field and the circumferential temperature gradient generates an unbalanced magnetic torque on the thermomagnetic rotor, driving the thermomagnetic rotor to rotate.

[0031] The rotational mechanical energy of the thermomagnetic rotor is converted into electrical energy;

[0032] The electrical energy is rectified, stored, and stabilized to supply power to online monitoring equipment on the transmission line. This application's solution constructs a thermomagnetic drive energy harvesting structure consisting of a thermomagnetic rotor, a thermally conductive insulating coupling section, a heat dissipation unit, and a magnetic field biasing component. This structure converts the Joule heat generated during the operation of the high-voltage direct current (HVDC) transmission line and its steady-state weak temperature difference with the environment into a circumferential temperature gradient of the thermomagnetic rotor. Furthermore, it utilizes the temperature-sensitive characteristics of the thermomagnetic materials to generate differences in magnetic response capabilities. Under the synergistic effect of the bias magnetic field, an unbalanced magnetic torque is formed to drive the rotor's rotation. Finally, this is converted into electrical energy output through a driven power generation structure. Thus, without relying on alternating magnetic fields or external mechanical excitation, this solution achieves efficient, continuous, and maintenance-free utilization of low-grade thermal energy in the steady electromagnetic environment of HVDC transmission lines, providing a stable and reliable self-powered solution for online monitoring equipment on transmission lines. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the overall appearance of the device according to Embodiment 1 of this application;

[0035] Figure 2 This is a schematic diagram of the internal structure of the device according to Embodiment 1 of this application;

[0036] Figure 3 This is a schematic diagram of the thermomagnetic drive structure and heat flow path in Embodiment 1 of this application;

[0037] Figure 4 This is a schematic diagram of the stator structure of the electromagnetic power generation unit according to Embodiment 1 of this application;

[0038] Figure 5 This is a schematic diagram of the rotor structure of the electromagnetic power generation unit according to Embodiment 1 of this application;

[0039] Figure 6 This is a schematic diagram of the stator and electrode layer arrangement of the triboelectric power generation unit according to Embodiment 1 of this application;

[0040] Figure 7 This is a schematic diagram of the second friction material layer structure of the triboelectric power generation unit in Embodiment 1 of this application;

[0041] Figure 8 This is a schematic diagram of the rotor and first friction material layer arrangement of the triboelectric power generation unit according to Embodiment 1 of this application;

[0042] Figure 9 This is a schematic diagram of the layered assembly structure of the triboelectric power generation unit according to Embodiment 1 of this application;

[0043] Figure 10 This is a schematic diagram of the energy management unit circuit of Embodiment 1 of this application;

[0044] Figure 11 This is a schematic diagram of the overall appearance of the device according to Embodiment 2 of this application;

[0045] Figure 12 This is a schematic diagram of the internal structure of the device according to Embodiment 2 of this application;

[0046] Figure 13 This is a schematic diagram of the single-sided thermomagnetic drive structure and heat flow path in Embodiment 2 of this application;

[0047] Figure 14 This is a schematic diagram of the end face structure of the electromagnetic-triboelectric hybrid power generation unit according to Embodiment 2 of this application;

[0048] Figure 15 This is a schematic diagram of the stator outer cylinder and electrode array structure of the composite power generation unit according to Embodiment 2 of this application;

[0049] Figure 16 This is a schematic diagram of the rotor structure of the composite power generation unit according to Embodiment 2 of this application;

[0050] Figure 17 This is a schematic diagram of the transmission of the composite power generation unit in Embodiment 2 of this application;

[0051] Figure 18 This is a schematic diagram of a self-powered high-voltage direct current transmission line method based on the aforementioned device, as described in this application.

[0052] In the diagram: 1-DC transmission line; 2-device housing; 3-heat dissipation unit; 4-thermal magnetic ring rotor; 5-rotating shaft; 6-magnetic field biasing component; 7-thermally conductive insulating coupling part; 8-electromagnetic power generation unit; 81-electromagnetic power generation stator; 82-coil; 83-electromagnetic power generation rotor; 84-power generation magnetic component; 9-triboelectric power generation unit; 91-triboelectric stator; 92-electrode layer; 93-second friction material layer; 94-triboelectric rotor; 95-first friction material layer; 10-energy management unit; 14-first thermal magnetic ring rotor; 15-second thermal magnetic ring rotor; 19-composite power generation unit; 191-stator outer cylinder; 192-electrode array; 193-coil; 194-rotor inner cylinder; 195-first friction material blade; 196-power generation magnetic component; 197-support fixing component. Detailed Implementation

[0053] To facilitate a clearer understanding of the purpose, technical solution, and advantages of this application, the following description, in conjunction with the accompanying drawings and specific embodiments, will further illustrate this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification.

[0054] This application can also be implemented or applied through other different specific examples, and the details in this specification can also be modified and changed based on different viewpoints and applications without departing from the spirit of this application.

[0055] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0056] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Secondly, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0057] In the embodiments of this application, such as Figures 1-17 As shown, this application provides a thermomagnetic drive-based high-voltage direct current transmission line temperature difference energy harvesting device, the device including at least one thermomagnetic rotor made of a material whose magnetic response characteristics change with temperature;

[0058] A thermally conductive and insulating coupling part is disposed between the DC transmission line and the thermomagnetic rotor and is used to conduct the heat of the line to the heat source side area of ​​the thermomagnetic rotor while achieving electrical insulation.

[0059] A heat dissipation unit is disposed on the side of the thermomagnetic rotor away from the wire and is used to dissipate heat from the cold source side region of the thermomagnetic rotor to the environment and to form a circumferential temperature gradient on the thermomagnetic rotor.

[0060] A magnetic field biasing element, disposed adjacent to the thermomagnetic rotor, provides a bias magnetic field. The circumferential temperature gradient causes a high-temperature weak magnetic response region and a low-temperature strong magnetic response region to be generated on the thermomagnetic rotor. Under the action of the bias magnetic field, the magnetic attraction force on the low-temperature strong magnetic response region is greater than that on the high-temperature weak magnetic response region. Furthermore, due to the predetermined relative positions of the thermally conductive insulating coupling part and the heat dissipation unit in the circumferential direction, the magnetic attraction force forms an asymmetrical distribution on the thermomagnetic rotor, thereby generating an unbalanced magnetic torque to drive its rotation.

[0061] A driven power generation structure is mechanically coupled to the thermomagnetic rotor and is used to convert the rotational mechanical energy of the thermomagnetic rotor into electrical energy output.

[0062] The thermomagnetic rotors include at least two arranged along the same axis of rotation;

[0063] The magnetic field biasing element is configured to make the driving torque generated by each thermomagnetic rotor have the same direction, so as to jointly drive the shaft to rotate.

[0064] The driven power generation structure includes an electromagnetic power generation unit and / or a triboelectric power generation unit; wherein, the electromagnetic power generation unit includes a power generation magnetic component that rotates with the thermomagnetic rotor and a coil that is fixed relative to the device housing, and induced electrical energy is generated through the relative motion between the power generation magnetic component and the coil;

[0065] The triboelectric power generation unit includes a first friction material layer that rotates with the thermomagnetic rotor and a second friction material layer that is fixed relative to the outer casing of the device. Triboelectric energy is generated through periodic contact separation or sliding friction between the first friction material layer and the second friction material layer.

[0066] The electromagnetic power generation unit and the triboelectric power generation unit are integrated into a composite power generation unit; the composite power generation unit includes a rotor and a stator coaxially arranged with the thermomagnetic rotor, the rotor is provided with a power generation magnetic component and a first friction material, and the stator is provided with a coil and an electrode layer.

[0067] The thermally conductive and insulating coupling part is selected from an arc-shaped thermally conductive pad, a semi-enclosed thermally conductive cover, or a thermally conductive shoe, and its material is selected from aluminum nitride ceramic, alumina ceramic, boron nitride composite material, mica-based material, or thermally conductive and insulating silicone.

[0068] The heat dissipation unit is selected from heat dissipation fins, heat pipes, heat-conducting blocks, or radiative heat dissipation layers.

[0069] The device also includes an energy management unit;

[0070] The energy management unit is electrically connected to the output terminal of the driven power generation structure and is used to rectify, store, and stabilize the electrical energy to output a stable DC voltage.

[0071] Preferably, the thermomagnetic material has a Curie temperature Tc. When the local temperature of the thermomagnetic rotor is close to or below Tc, its magnetization, permeability, and / or susceptibility are at a high level, exhibiting a strong magnetic response. When the local temperature of the thermomagnetic rotor is far from and above Tc, its magnetization, permeability, and / or susceptibility decrease, exhibiting a weak magnetic response. The circumferential temperature gradient causes the thermomagnetic rotor to simultaneously include the high-temperature weak magnetic response region and the low-temperature strong magnetic response region in the circumferential direction.

[0072] Furthermore, the thermomagnetic rotor is made of at least one thermomagnetic material selected from the group consisting of gadolinium (Gd), Gd-based alloys, La-Fe-Si-H alloys, MnFePAs alloys, NiMn-based Heusler alloys, or composites thereof.

[0073] In other words, the core driving force in this application comes from the synergistic effect of the "thermomagnetic effect" and the "bias magnetic field." Specifically, the temperature characteristics of the thermomagnetic material: the thermomagnetic material selected in this application is a type of magnetic material with a specific Curie temperature (Tc). Below Tc, the magnetic moments inside the material are arranged in an orderly manner, exhibiting high magnetization (or permeability, magnetic susceptibility) and strong response to external magnetic fields (low-temperature strong magnetic response). When the material temperature rises and approaches or exceeds Tc, thermal disturbances disrupt the orderly arrangement of the magnetic moments, causing a sharp decrease in parameters such as magnetization, and a significant weakening of the response to external magnetic fields (high-temperature weak magnetic response).

[0074] For the formation of temperature gradients, such as Figure 3 As shown, the Joule heat from the DC transmission conductor 1 is conducted to the side of the thermomagnetic ring rotor 4 closest to the conductor (heat source side) through the thermally conductive insulating coupling part 7, causing its local temperature to rise; at the same time, the heat dissipation unit 3 dissipates the heat from the side of the rotor away from the conductor (cold source side) into the environment. Due to the continuous generation of Joule heat from the conductor and the continuous cooling of the environment, a stable temperature gradient is established in the circumferential direction of the thermomagnetic rotor, pointing from the heat source side to the cold source side.

[0075] Regarding the generation of magnetic response differences and unbalanced torques, under this temperature gradient, the thermomagnetic ring rotor 4 is divided into two parts: a high-temperature weak magnetic response region near the conductor and a low-temperature strong magnetic response region away from the conductor. The magnetic field biasing component 6 provides a constant or quasi-constant bias magnetic field near the rotor. At this time, the magnetic attraction F1 generated by the bias magnetic field on the low-temperature strong magnetic response region will be much greater than the magnetic attraction F2 generated on the high-temperature weak magnetic response region. Crucially, the placement of the thermally conductive insulating coupling part 7 and the heat dissipation unit 3 ensures that the low-temperature strong magnetic response region and the high-temperature weak magnetic response region are not symmetrically distributed on both sides of the shaft, but rather form a specific angular bias relative to the centerline of the shaft.

[0076] Therefore, the attractive forces F1 and F2 are unequal in magnitude and their lines of action do not pass through the same center of rotation, thus creating a net torque M = (F1 - F2) × r (where r is the effective lever arm) about the rotor axis 5. This torque drives the thermomagnetic rotor to rotate continuously. As the rotor rotates, new material enters the heat source / cold source region, repeating the above process, thereby forming a continuous or step-like rotational motion.

[0077] Specifically, in this embodiment, a thermomagnetic drive energy harvesting structure is constructed by utilizing the inherent Joule heat of the high-voltage direct current transmission line during operation and the temperature difference between it and the external natural environment. This structure consists of a thermomagnetic ring rotor, a magnetic field biasing component, a thermally conductive and insulating coupling part, and a heat dissipation unit. This structure can obtain rotational mechanical energy without relying on an alternating magnetic field and further drive the driven power generation structure to output electrical energy.

[0078] In this application, a driven power generation structure is used to convert the rotational mechanical energy generated by thermomagnetic drive into electrical energy. The driven power generation structure can be configured as a single power generation structure or a composite power generation structure according to output requirements. For example, it can employ an electromagnetic power generation unit, a triboelectric power generation unit, or a combination of both, and can also be replaced with other rotary energy conversion units as needed. The specific form of the driven power generation structure described above does not constitute a limitation on the thermomagnetic drive energy harvesting method of this application. Embodiments 1 and 2 can employ the same energy management unit, which is used for rectifying, storing, stabilizing, and managing the output electrical signal of the power generation unit.

[0079] Example 1: Single-Thermomagnetic Ring Driven Composite Self-Powered Device

[0080] This embodiment provides a single-thermal magnetic ring driven composite self-powered device based on the temperature difference between DC transmission lines and the environment. Figure 1 This is a schematic diagram of the overall appearance of the device. Figure 2 This is a schematic diagram of the internal structure of the device. Figure 3 This is a schematic diagram of the thermomagnetic drive structure and heat flow path. Figure 4 and Figure 5This is a schematic diagram of the electromagnetic power generation unit structure. Figures 6 to 9 This is a schematic diagram of a triboelectric power generation unit. Figure 10 This is the circuit schematic for the energy management unit.

[0081] The device includes a DC transmission line 1, a device housing 2, a heat dissipation unit 3, a thermomagnetic ring rotor 4, a rotating shaft 5, a magnetic field biasing component 6, a thermally conductive and insulating coupling part 7, an electromagnetic power generation unit 8, a triboelectric power generation unit 9, and an energy management unit 10.

[0082] The specific technical solution is described below, such as Figure 1 and Figure 2 As shown, the single thermomagnetic ring driven composite self-powered device is located outside the DC transmission line 1. The device housing 2 forms an installation space for accommodating the thermomagnetic ring rotor 4, the rotating shaft 5, the magnetic field biasing component 6, the thermally conductive and insulating coupling part 7, the electromagnetic power generation unit 8, and the triboelectric power generation unit 9. The thermomagnetic ring rotor 4 is mounted on the rotating shaft 5 and serves as a thermomagnetic drive component; the magnetic field biasing component 6 is located in a local area near the thermomagnetic ring rotor 4 to provide a bias magnetic field; the thermally conductive and insulating coupling part 7 is located between the DC transmission line 1 and the thermomagnetic ring rotor 4 to achieve thermal coupling between the DC transmission line 1 and the heat source side of the thermomagnetic ring rotor 4; the heat dissipation unit 3 is located on the side of the device housing 2 away from the DC transmission line 1 to enhance heat exchange between the cold source side of the thermomagnetic ring rotor 4 and the external environment; the electromagnetic power generation unit 8 and the triboelectric power generation unit 9 are located on one or both sides of the rotating shaft 5 and serve as driven power generation structures driven by the rotating shaft 5.

[0083] like Figure 2 and Figure 3As shown, the thermomagnetic ring rotor 4 is fixedly mounted on the rotating shaft 5 and can rotate synchronously with the rotating shaft 5. The thermomagnetic ring rotor 4 is made of a temperature-sensitive thermomagnetic material, which has reversible magnetic response characteristics within a preset operating temperature range. Its magnetic response capability weakens as the temperature increases and recovers as the temperature decreases. A thermally conductive and insulating coupling part 7 is disposed between the DC transmission line 1 and the thermomagnetic ring rotor 4. It is a fixed thermally conductive and insulating component used to couple the heat generated during the operation of the DC transmission line 1 to a local area on the heat source side of the thermomagnetic ring rotor 4 while maintaining electrical insulation. The thermally conductive and insulating coupling part 7 can be an arc-shaped thermally conductive and insulating pad, a semi-enclosed thermally conductive cover, a thermally conductive and insulating heat shoe, or a combination thereof. One side of the thermally conductive and insulating coupling part 7 is disposed near the DC transmission line 1 to receive the heat from the line; the other side is disposed near the heat source side of the thermomagnetic ring rotor 4 to couple the heat to a local area on the thermomagnetic ring rotor 4. A preset gap can be maintained between the thermally conductive and insulating coupling part 7 and the thermomagnetic ring rotor 4 to avoid affecting the rotation of the thermomagnetic ring rotor 4. The thermally conductive and insulating coupling part 7 can be made of materials with thermal conductivity, electrical insulation, heat resistance, and weather resistance, including but not limited to aluminum nitride ceramic, alumina ceramic, boron nitride-filled thermally conductive and insulating composite material, mica-based thermally conductive and insulating material, thermally conductive and insulating silicone pad, or combinations thereof. When the device is working, the heat generated by the operation of the DC transmission line 1 enters the side of the thermomagnetic ring rotor 4 closest to the line through the thermally conductive and insulating coupling part 7, which forms the heat source side; the side of the thermomagnetic ring rotor 4 away from the line dissipates heat to the external environment through the heat dissipation unit 3, which forms the cold source side, thereby creating a temperature distribution difference in the circumference of the thermomagnetic ring rotor 4, and further creating a difference in magnetic response capability. The magnetic field biasing element 6 is used to form a bias magnetic field, generating magnetic attraction forces of different magnitudes on different magnetic response capability regions in the thermomagnetic ring rotor 4, thereby forming an unbalanced magnetic torque. [In a further embodiment of this application, this side forms a cold source side, thereby creating a temperature gradient in the circumferential direction of the thermomagnetic ring rotor 4 from the heat source side to the cold source side. Under this temperature gradient, both a high-temperature weak magnetic response region and a low-temperature strong magnetic response region exist simultaneously on the thermomagnetic ring rotor 4. The magnetic field biasing element 6 is used to form a bias magnetic field, and the magnetic attraction force acting on the low-temperature strong magnetic response region is much greater than the magnetic attraction force acting on the high-temperature weak magnetic response region. Furthermore, due to the preset relative positional relationship between these two regions and the heat source and cold source in the circumferential direction, the magnetic attraction force is asymmetrically distributed, thereby forming a net unbalanced magnetic torque around the rotating shaft 5], driving the thermomagnetic ring rotor 4 and the rotating shaft 5 to rotate continuously or intermittently. In one alternative embodiment, the magnetic field biasing element 6 is a permanent magnet, a magnet array, a yoke assembly, or a magnetic structure capable of forming a bias magnetic field in a localized area of ​​the thermomagnetic ring rotor 4; the heat dissipation unit 3 is a heat sink, heat dissipation fins, a heat-conducting block, a heat pipe, a radiative heat dissipation layer, or a combination thereof. Figure 2 , Figure 4 and Figure 5As shown, the electromagnetic power generation unit 8 is disposed on one or both sides of the rotating shaft 5. The electromagnetic power generation unit 8 includes an electromagnetic power generation stator 81, a coil 82, an electromagnetic power generation rotor 83, and a power generation magnetic component 84. The coil 82 is disposed on the electromagnetic power generation stator 81, which is fixedly connected to the device housing 2; the power generation magnetic component 84 is disposed on the electromagnetic power generation rotor 83, which is connected to the rotating shaft 5 and can rotate synchronously with the rotating shaft 5. When the rotating shaft 5 rotates, the power generation magnetic component 84 undergoes periodic movement relative to the coil 82, causing a change in the magnetic flux passing through the coil 82 and generating an induced electrical signal in the coil 82. The power generation magnetic component 84 can be a permanent magnet, a magnet array, or a magnetic component capable of generating changes in magnetic flux.

[0084] like Figures 6 to 9 As shown, the triboelectric power generation unit 9 is disposed on one or both sides of the rotating shaft 5. The triboelectric power generation unit 9 includes a triboelectric stator 91, an electrode layer 92, a second friction material layer 93, a triboelectric rotor 94, and a first friction material layer 95. The electrode layer 92 and the second friction material layer 93 are disposed on the triboelectric stator 91, which is fixedly connected to the device housing 2; the first friction material layer 95 is disposed on the triboelectric rotor 94, which is connected to the rotating shaft 5 and can rotate synchronously with the rotating shaft 5. When the rotating shaft 5 rotates, the first friction material layer 95 and the second friction material layer 93 undergo periodic contact, separation, or sliding friction, causing charge transfer and charge separation on their surfaces, and outputting triboelectric signals through the electrode layer 92. The first friction material layer 95 and the second friction material layer 93 are made of materials with different electronegativity in the triboelectric sequence; the electrode layer 92 can be made of copper, aluminum, silver, ITO, or carbon-based conductive materials.

[0085] like Figure 10 As shown, the output terminals of both the electromagnetic power generation unit 8 and the triboelectric power generation unit 9 are electrically connected to the energy management unit 10. The energy management unit 10 includes a first rectifier bridge, a second rectifier bridge, an energy storage capacitor, and a DC-DC regulated output circuit. The electrical signals output from the electromagnetic power generation unit 8 and the triboelectric power generation unit 9 are converted into DC signals by the first and second rectifier bridges, respectively, and then fed into the energy storage capacitor. After being converted into a stable DC voltage by the DC-DC regulated output circuit, the voltage is supplied to the online monitoring equipment for the DC transmission line.

[0086] Example 2: Composite Self-Powered Device Driven by Dual Thermomagnetic Rings

[0087] This embodiment relates to a dual-thermal magnetic ring driven composite self-powered device based on the temperature difference between a DC transmission line and the environment. For example... Figure 11 The image shown is a schematic diagram of the overall appearance and structure of the device. Figure 12 This is a schematic diagram of the internal structure of the device. Figure 13This is a schematic diagram of the single-sided thermomagnetic drive structure and heat flow path of a dual thermomagnetic ring driven device. Figures 14 to 16 An integrated electromagnetic-triboelectric power generation unit is shown. Figure 17 The transmission structure of the dual-thermal magnetic ring driven composite power generation unit is shown.

[0088] This embodiment is similar to Embodiment 1 in that both utilize the Joule heat generated during the operation of the DC transmission line and the temperature difference between it and the external environment to create a circumferential temperature distribution difference in the thermomagnetic ring rotor, further resulting in a difference in magnetic response capability. Under the bias magnetic field of the magnetic field biasing component, the thermomagnetic ring rotor generates an unbalanced magnetic torque, thereby driving the shaft to rotate. The same thermomagnetic drive mechanism, thermally conductive and insulating coupling method, heat dissipation method, and energy management method can be referred to Embodiment 1 and will not be described again.

[0089] The difference in this embodiment is that the device adopts a dual thermomagnetic ring drive structure and integrates the electromagnetic power generation structure and the triboelectric power generation structure into a composite power generation unit. The device includes a DC transmission line 1, a device housing 2, a heat dissipation unit 3, a first thermomagnetic ring rotor 14, a second thermomagnetic ring rotor 15, a rotating shaft 5, a magnetic field biasing component 6, a thermally conductive and insulating coupling part 7, a composite power generation unit 19, and an energy management unit 10. The first thermomagnetic ring rotor 14 and the second thermomagnetic ring rotor 15 are respectively disposed at both ends of the rotating shaft 5 and together serve as thermomagnetic drive components. The composite power generation unit 19 is disposed between the first thermomagnetic ring rotor 14 and the second thermomagnetic ring rotor 15, and is used to convert the rotational mechanical energy output from the rotating shaft 5 into electromagnetic induction energy and triboelectric energy.

[0090] The specific technical solution is described below:

[0091] like Figure 11 and Figure 12 As shown, the dual-thermomagnetic-ring driven composite self-powered device is disposed outside the DC transmission line 1. The device housing 2 forms an installation space for accommodating the first thermomagnetic-ring rotor 14, the second thermomagnetic-ring rotor 15, the shaft 5, the magnetic field biasing component 6, the thermally conductive and insulating coupling part 7, and the composite power generation unit 19. The thermally conductive and insulating coupling part 7 and the heat dissipation unit 3 are arranged in accordance with Embodiment 1, forming a heat source side and a cold source side on the two thermomagnetic-ring rotors.

[0092] like Figure 12 and Figure 13As shown, the first thermomagnetic ring rotor 14 and the second thermomagnetic ring rotor 15 are fixedly installed at both ends of the rotating shaft 5 and can rotate synchronously with the rotating shaft 5. Both thermomagnetic ring rotors are made of temperature-sensitive thermomagnetic materials and form a heat source side and a cold source side respectively through a thermally conductive and insulating coupling part 7 and a heat dissipation unit 3. The structure, material composition and thermal coupling method of the thermally conductive and insulating coupling part 7 can be referred to the relevant description of the thermally conductive and insulating coupling part 7 in Embodiment 1. Its thermomagnetic driving mechanism is the same as the driving mechanism of the thermomagnetic ring rotor 4 in Embodiment 1. The magnetic field biasing member 6 is disposed on the side of the two thermomagnetic ring rotors near the heat source, and is used to make the first thermomagnetic ring rotor 14 and the second thermomagnetic ring rotor 15 generate unbalanced magnetic torques respectively. By adjusting the installation position and magnetic pole direction of the magnetic field biasing member 6, the driving torques generated by the two thermomagnetic ring rotors can act on the rotating shaft 5 in the same direction, thereby driving the rotating shaft 5 to rotate.

[0093] like Figures 14 to 16 As shown, the composite power generation unit 19 is disposed between the first thermomagnetic ring rotor 14 and the second thermomagnetic ring rotor 15, and is connected to the rotating shaft 5. The composite power generation unit 19 includes a stator outer cylinder 191, an electrode array 192, a coil 193, a rotor inner cylinder 194, a first friction material blade 195, a power generation magnetic component 196, and a support and fixing component 197. The stator outer cylinder 191 is fixedly disposed inside the device housing 2, and the electrode array 192 and the coil 193 are disposed on the stator outer cylinder 191; the rotor inner cylinder 194 is disposed inside the stator outer cylinder 191 and is fixedly connected to the rotating shaft 5. The first friction material blade 195 and the power generation magnetic component 196 are disposed on the rotor inner cylinder 194 or on the support and fixing component 197 connected to the rotor inner cylinder 194, and can rotate synchronously with the rotating shaft 5.

[0094] like Figures 14 to 17 As shown, when the first thermomagnetic ring rotor 14 and the second thermomagnetic ring rotor 15 drive the rotating shaft 5 to rotate, the rotating shaft 5 drives the rotor inner cylinder 194, the first friction material blade 195, and the power generation magnetic component 196 to rotate synchronously. The first friction material blade 195 periodically contacts, separates, or slides against the electrode array 192, which also serves as a friction contact part, thereby outputting a triboelectric signal. At the same time, the power generation magnetic component 196 periodically moves relative to the coil 193, causing a change in the magnetic flux passing through the coil 193 and generating an induced electric signal in the coil 193. Through this structure, the electromagnetic power generation structure and the triboelectric power generation structure are integrated into the same composite power generation unit 19. The first friction material blade 195 and the electrode array 192 can be materials with different electronegativity in the triboelectric sequence; the electrode array 192 can be made of copper, aluminum, silver, ITO, or carbon-based conductive materials; the power generation magnetic component 196 can be a permanent magnet, a magnet array, or a magnetic component capable of generating changes in magnetic flux.

[0095] The output terminal of the combined power generation unit 19 is electrically connected to the energy management unit 10. The circuit structure of the energy management unit 10 can be found in [reference needed]. Figure 10 It is used to rectify, store, and stabilize the electromagnetic induction and triboelectric signals output by the composite power generation unit 19, and to supply power to the online monitoring equipment of the DC transmission line. In this embodiment, the Joule heat generated by the DC transmission conductor 1 drives the first thermomagnetic ring rotor 14 and the second thermomagnetic ring rotor 15 to jointly drive the rotating shaft 5 to rotate. The rotating shaft 5 further drives the composite power generation unit 19 to generate electrical energy, which is finally processed by the energy management unit 10 and output.

[0096] Compared with existing technologies, this application offers the following advantages: It adapts to the stable electromagnetic environment of high-voltage direct current (HVDC) transmission lines. Using thermomagnetic rotary drive as its core energy extraction mechanism, it does not rely on the alternating magnetic field in AC transmission lines or external vibration excitation, enabling it to operate in the stable electric and magnetic field environment of HVDC transmission lines. Compared to self-powered methods that partially rely on AC electromagnetic environments or external mechanical excitation, this application provides a self-powered technology path suitable for DC scenarios for online monitoring equipment of HVDC transmission lines.

[0097] This application provides a thermomagnetic energy harvesting structure for weak temperature differences between conductors and the environment: Addressing the persistent weak temperature difference energy between HVDC transmission conductors and the external environment, this application presents a thermomagnetic driven energy harvesting structure comprising a thermally conductive and insulated coupling section, a thermomagnetic ring rotor, a magnetic field biasing component, and a heat dissipation unit. This structure can harvest low-grade thermal energy from the conductor side while maintaining electrical insulation, and convert it into rotational mechanical energy of the shaft through thermomagnetic drive, thereby improving the adaptability of weak temperature difference energy utilization in self-powered HVDC transmission lines. Simultaneously, this application also provides a novel thermomagnetic rotary energy harvesting structure for utilizing this type of weak temperature difference thermal energy.

[0098] The thermomagnetic drive structure described in this solution can be replaced with a thermomagnetic disk, a thermomagnetic wheel, a segmented thermomagnetic rotor, or a circumferential array of thermomagnetic material components; the magnetic field biasing component can also be a permanent magnet array, a magnetic yoke reinforcement structure, or an adjustable magnet component to adapt to different thermomagnetic materials and torque output requirements.

[0099] The thermally conductive and insulating coupling part and the heat dissipation unit described in this solution can be made of different materials or have different structural forms; the thermally conductive and insulating coupling part can be made of aluminum nitride ceramic, alumina ceramic, boron nitride filled thermally conductive and insulating composite material, mica-based thermally conductive and insulating material, thermally conductive and insulating silicone pad or a combination thereof, and the heat dissipation unit can be made of heat dissipation fins, heat-conducting blocks, heat pipes, radiative heat dissipation layers or natural air cooling structure.

[0100] The composite power generation unit described in this solution can be structurally replaced according to output requirements; the electromagnetic power generation unit can adopt a rotor magnet-stator coil structure, a rotor coil-stator magnet structure, or a multi-pole magnet array structure; the triboelectric power generation unit can adopt a contact separation type, sliding friction type, single electrode type, or free layer type structure.

[0101] To achieve the above objectives, this application also provides a thermomagnetic power generation assembly for a thermoelectric energy harvesting device for high voltage direct current transmission lines. The thermomagnetic power generation assembly includes at least one thermomagnetic rotor, which is made of a material whose magnetic response characteristics change with temperature, and is configured to form a temperature gradient in its circumferential direction under the combined action of an external heat source and a cold source.

[0102] A magnetic field biasing element, disposed adjacent to the thermomagnetic rotor and used in conjunction with the temperature gradient, generates an unbalanced magnetic torque on the thermomagnetic rotor to drive its rotation; and...

[0103] A driven power generation structure is mechanically coupled to the thermomagnetic rotor and is used to convert the rotational mechanical energy of the thermomagnetic rotor into electrical energy output.

[0104] The driven power generation structure includes an electromagnetic power generation unit and / or a triboelectric power generation unit.

[0105] To achieve the above objectives, such as Figure 18 As shown, this application also provides a self-powered high-voltage direct current transmission line method based on the aforementioned device, the method comprising the following steps:

[0106] By utilizing the Joule heat of the DC transmission line and its temperature difference with the environment, a circumferential temperature gradient is established on at least one thermomagnetic rotor.

[0107] The combined effect of the bias magnetic field and the circumferential temperature gradient generates an unbalanced magnetic torque on the thermomagnetic rotor, driving the thermomagnetic rotor to rotate.

[0108] The rotational mechanical energy of the thermomagnetic rotor is converted into electrical energy;

[0109] The electrical energy is rectified, stored, and stabilized to supply power to online monitoring equipment on the transmission line.

[0110] This application proposes a thermomagnetic drive energy harvesting structure consisting of a thermomagnetic rotor, a thermally conductive and insulating coupling part, a heat dissipation unit, and a magnetic field biasing component. This structure converts the Joule heat generated during the operation of high-voltage direct current (HVDC) transmission lines and the steady-state weak temperature difference between the rotor and the environment into a circumferential temperature gradient of the thermomagnetic rotor. By utilizing the temperature-sensitive characteristics of the thermomagnetic materials to generate differences in magnetic response capabilities, an unbalanced magnetic torque is formed under the synergistic effect of the bias magnetic field to drive the rotor to rotate. Finally, the rotor is converted into electrical energy output through a driven power generation structure. Thus, without relying on alternating magnetic fields or external mechanical excitation, this solution achieves efficient, continuous, and maintenance-free utilization of low-grade thermal energy in the steady electromagnetic environment of HVDC transmission lines, providing a stable and reliable self-powered solution for online monitoring equipment of transmission lines.

[0111] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A thermomagnetic driven high-voltage direct current transmission line temperature difference energy harvesting device, characterized in that, The device includes at least one thermomagnetic rotor made of a material whose magnetic response characteristics change with temperature. A thermally conductive and insulating coupling part is disposed between the DC transmission line and the thermomagnetic rotor and is used to conduct the heat of the line to the heat source side area of ​​the thermomagnetic rotor while achieving electrical insulation. A heat dissipation unit is disposed on the side of the thermomagnetic rotor away from the wire and is used to dissipate heat from the cold source side region of the thermomagnetic rotor to the environment and to form a circumferential temperature gradient on the thermomagnetic rotor. A magnetic field biasing element is disposed adjacent to the thermomagnetic rotor to provide a bias magnetic field; the circumferential temperature gradient causes the thermomagnetic rotor to produce a circumferentially distributed difference in magnetic response capability, which, together with the bias magnetic field, generates an unbalanced magnetic torque on the thermomagnetic rotor to drive its rotation. as well as, A driven power generation structure is mechanically coupled to the thermomagnetic rotor and is used to convert the rotational mechanical energy of the thermomagnetic rotor into electrical energy output.

2. The thermomagnetic driven high-voltage direct current transmission line temperature difference energy harvesting device according to claim 1, characterized in that, The thermomagnetic rotors include at least two arranged along the same axis of rotation; The magnetic field biasing element is configured to ensure that the driving torque generated by each thermomagnetic rotor is in the same direction.

3. The thermomagnetic driven high-voltage direct current transmission line temperature difference energy harvesting device according to claim 1, characterized in that, The driven power generation structure includes an electromagnetic power generation unit and / or a triboelectric power generation unit; wherein, the electromagnetic power generation unit includes a power generation magnetic component that rotates with the thermomagnetic rotor and a coil that is fixed relative to the device housing, and induced electrical energy is generated through the relative motion between the power generation magnetic component and the coil; The triboelectric power generation unit includes a first friction material layer that rotates with the thermomagnetic rotor and a second friction material layer that is fixed relative to the outer casing of the device. Triboelectric energy is generated through periodic contact separation or sliding friction between the first friction material layer and the second friction material layer.

4. The thermomagnetic driven high-voltage direct current transmission line temperature difference energy harvesting device according to claim 3, characterized in that, The electromagnetic power generation unit and the triboelectric power generation unit are integrated into a composite power generation unit; the composite power generation unit includes a rotor and a stator coaxially arranged with the thermomagnetic rotor, the rotor is provided with a power generation magnetic component and a first friction material, and the stator is provided with a coil and an electrode layer.

5. The thermomagnetic driven high-voltage direct current transmission line temperature difference energy harvesting device according to claim 1, characterized in that, The thermally conductive and insulating coupling part is selected from an arc-shaped thermally conductive pad, a semi-enclosed thermally conductive cover, or a thermally conductive shoe, and its material is selected from aluminum nitride ceramic, alumina ceramic, boron nitride composite material, mica-based material, or thermally conductive and insulating silicone.

6. The thermomagnetic driven high-voltage direct current transmission line temperature difference energy harvesting device according to claim 1, characterized in that, The heat dissipation unit is selected from heat dissipation fins, heat pipes, heat-conducting blocks, or radiative heat dissipation layers.

7. The thermomagnetic driven high-voltage direct current transmission line temperature difference energy harvesting device according to claim 1, characterized in that, The device also includes an energy management unit; The energy management unit is electrically connected to the output terminal of the driven power generation structure and is used to rectify, store, and stabilize the electrical energy.

8. A thermomagnetic power generation component for a temperature difference energy harvesting device in a high-voltage direct current transmission line, characterized in that, The thermomagnetic generator includes at least one thermomagnetic rotor made of a material whose magnetic response characteristics vary with temperature, and is configured to form a temperature gradient in its circumferential direction under the combined action of an external heat source and a cold source. A magnetic field biasing element is disposed adjacent to the thermomagnetic rotor and is used to work in conjunction with the temperature gradient to generate an unbalanced magnetic torque on the thermomagnetic rotor to drive its rotation. as well as, A driven power generation structure is mechanically coupled to the thermomagnetic rotor and is used to convert the rotational mechanical energy of the thermomagnetic rotor into electrical energy output.

9. A thermomagnetic power generation component for a high-voltage direct current transmission line temperature difference energy harvesting device according to claim 8, characterized in that, The driven power generation structure includes an electromagnetic power generation unit and / or a triboelectric power generation unit.

10. A method for self-powering a high-voltage direct current transmission line based on the device according to any one of claims 1 to 7, characterized in that, The method includes the following steps: By utilizing the Joule heat of the DC transmission line and its temperature difference with the environment, a circumferential temperature gradient is established on at least one thermomagnetic rotor. The combined effect of the bias magnetic field and the circumferential temperature gradient generates an unbalanced magnetic torque on the thermomagnetic rotor, driving the thermomagnetic rotor to rotate. The rotational mechanical energy of the thermomagnetic rotor is converted into electrical energy; The electrical energy is rectified, stored, and stabilized to supply power to online monitoring equipment on the transmission line.

Images