Magnetic field energy extraction device for back-shaped steel pole tower under ac transmission line and setting method thereof

Abstract

The application provides a magnetic field energy extraction device for a U-shaped steel structure tower under an AC transmission line and a setting method thereof. The device comprises a magnetic induction energy extraction component and an energy extraction circuit. The magnetic induction energy extraction component comprises a magnetic core and an energy extraction coil. The magnetic core penetrates the energy extraction coil. The magnetic core is arranged on a U-shaped piece, and two ends of the magnetic core are in contact with the U-shaped piece. The energy extraction coil is electrically connected to the energy extraction circuit. The energy extraction circuit is a resonance circuit. The resonance circuit comprises a resonance frequency adjusting component. The resonance frequency adjusting component is used for dynamically adjusting the resonance frequency of the energy extraction circuit according to the change of the inductance value of the energy extraction coil, so that the energy extraction circuit is kept in a resonance state. The magnetic field energy of the U-shaped steel structure tower can be converted into electric energy, and the energy conversion efficiency can be further improved.

Description

Technical Field

[0001] This invention relates to the field of magnetic field energy harvesting technology for AC transmission line towers, specifically to a magnetic field energy harvesting device and its installation method for a circular steel structure tower under an AC transmission line. Background Technology

[0002] High-voltage transmission lines are frequently affected by various natural and human factors. To ensure the safe operation of these lines, monitoring equipment needs to be installed, which places high demands on the economy and stability of their power supply systems. However, due to the widespread distribution of transmission line towers and their location in complex outdoor environments, power supply issues have become a major factor restricting the development of online monitoring devices for transmission lines.

[0003] The magnetic field energy around transmission line towers remains relatively stable. Theoretically, we can use these magnetic fields to obtain energy online. How to maximize the use of the magnetic field energy around transmission line towers for monitoring equipment has become an urgent task. Summary of the Invention

[0004] This invention provides a magnetic field energy harvesting device and its installation method for a circular steel structure tower under an AC transmission line, which can generate electricity using the magnetic field energy of the circular steel structure tower.

[0005] On the one hand, a magnetic field energy harvesting device for a circular steel structure tower under an AC transmission line is provided, comprising: Magnetic induction energy harvesting component and energy harvesting circuit; The magnetic induction energy harvesting component includes a magnetic core and an energy harvesting coil. The magnetic core passes through the energy harvesting coil and is disposed on a U-shaped component, with both ends of the magnetic core in contact with the U-shaped component. The energy harvesting coil is electrically connected to the energy harvesting circuit, which is a resonant circuit. The resonant circuit includes a resonant frequency adjustment component, which is used to dynamically adjust the resonant frequency of the energy harvesting circuit according to the change in the inductance value of the energy harvesting coil, so that the energy harvesting circuit remains in a resonant state.

[0006] Optionally, the energy harvesting circuit includes: The system includes a voltage source, a resistor, and a resonant frequency adjustment component. The resonant frequency adjustment component includes a variable capacitor and a capacitor controller. The voltage source, the resistor, the energy harvesting coil, and the variable capacitor are connected in series. The capacitor controller is used to determine the magnitude of the resonant frequency of the resonant circuit and the frequency of the voltage source, and to generate control commands to adjust the capacitance value of the variable capacitor.

[0007] Optionally, the capacitor controller is a phase comparator; the phase comparator is used to compare the phase of the voltage source voltage and the phase of the current in the series resonant circuit, and outputs a control signal according to the phase of the voltage source voltage and the phase of the current in the series resonant circuit to adjust the capacitance value of the variable capacitor.

[0008] Optionally, the variable capacitor includes: A capacitor module, comprising multiple capacitors connected in parallel, each capacitor being configured with a switch; The control module includes a first counter, a second counter, a first decoder, and a second decoder. The first counter is used to calculate the maximum number of the closed switch, and the second counter is used to calculate the minimum number of the open switch. The first decoder receives the signal from the first counter, and the second decoder receives the signal from the second counter. When the capacitor controller releases a positive signal, the first counter releases a first electrical signal to control the switch to close and connect the capacitor to the power extraction circuit. When the capacitor controller releases a negative signal, the second counter releases a second electrical signal to control the switch to open and disconnect the capacitor from the power extraction circuit.

[0009] Optionally, the number of magnetic induction energy harvesting components on the spiral member is multiple, and the multiple magnetic induction energy harvesting components are set according to the magnitude of the magnetic flux density at each position on the spiral member.

[0010] Optionally, the magnetic core comprises a plurality of stacked silicon steel magnetic chips.

[0011] Optionally, the energy harvesting coil is formed by energy harvesting wires, which are arranged on the surface of the magnetic core in a layered manner, and the number of layers of the energy harvesting wires is 2 to 5.

[0012] On the other hand, a method for installing a magnetic field energy harvesting device on a circular steel structure tower under an AC transmission line is provided, the method being applied to the magnetic field energy harvesting device on a circular steel structure tower under an AC transmission line as described in any of the preceding claims, comprising: Obtain the structural parameters and permeability curves of the spiral-shaped component and the magnetic core; A three-dimensional finite element module is established based on the structural parameters. The three-dimensional finite element model includes at least a spiral component and a power transmission line connected to the spiral component. The magnetic flux density distribution of the spiral component is determined by simulating the three-dimensional finite element model. Based on the magnetic flux density distribution, the setting position of the magnetic induction energy harvesting component is determined. The magnetic induction energy harvesting component includes a magnetic core and an energy harvesting coil, and the magnetic core passes through the energy harvesting coil. The magnetic core is simulated in a three-dimensional finite element model to determine its structure and configuration. An energy harvesting circuit is constructed, which is electrically connected to the energy harvesting coil. The energy harvesting circuit is a resonant circuit, which includes a resonant frequency adjustment component. The resonant frequency adjustment component is used to dynamically adjust the resonant frequency of the energy harvesting circuit according to the change of the inductance value of the energy harvesting coil, so that the energy harvesting circuit is maintained in a resonant state.

[0013] Optionally, determining the placement location of the magnetic induction energy harvesting component based on the magnetic flux density distribution includes: Based on the magnitude of the magnetic flux density in the spiral member, one or more installation positions are determined, and the magnetic induction energy harvesting components are sequentially installed at the installation positions.

[0014] Optionally, the magnetic core is simulated in a three-dimensional finite element model to determine its structure and arrangement, including: In the three-dimensional finite element model, the tilt angle of the magnetic core, the number of silicon steel magnetic chips included in the magnetic core, and the magnitude of the current in the transmission line are used as single variables. Based on the magnitude of the magnetic flux density passing through the magnetic core, the tilt angle of the magnetic core and the number of silicon steel magnetic chips are determined, so as to determine the structure and arrangement of the magnetic core.

[0015] The beneficial effects of the technical solutions provided in this disclosure are: This disclosure provides a magnetic field energy harvesting device for a U-shaped steel structure tower under an AC transmission line. The device includes a magnetic induction energy harvesting component and an energy harvesting circuit. The magnetic induction energy harvesting component generates electricity using the magnetic flux density of the U-shaped structure, converting the magnetic field energy around the U-shaped structure into electrical energy, which is then output through the energy harvesting circuit. The energy harvesting circuit is a resonant circuit. Compared to using a conventional resistive load circuit, using a resonant circuit as the energy harvesting circuit can improve the output power of the energy harvesting circuit. The energy harvesting circuit includes a resonant frequency adjustment component. During energy harvesting, the inductance of the energy harvesting coil fluctuates. By setting the resonant frequency adjustment component, when the energy harvesting coil fluctuates, i.e., when the resonant circuit transitions to a non-resonant state, the resonant frequency of the resonant circuit is adjusted, causing the resonant circuit to return to a resonant state. By continuously maintaining the resonant circuit in a resonant state, the output power of the energy harvesting circuit can be kept at a high level, thereby improving the energy harvesting effect. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this 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 some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the magnetic field energy harvesting device for a circular steel structure tower under an AC transmission line, provided in an embodiment of this disclosure. Figure 2 This is a schematic diagram of the structure of a magnetic induction energy harvesting component provided in an embodiment of this disclosure; Figure 3 This is a schematic diagram of an energy harvesting circuit provided in an embodiment of the present disclosure; Figure 4 This is a schematic diagram of the structure of a variable capacitor provided in an embodiment of the present disclosure; Figure 5 A flowchart illustrating a method for installing a magnetic field energy harvesting device on a circular steel structure tower under an AC transmission line, as provided in this embodiment of the present disclosure; Figure 6 This is a test data graph provided for an embodiment of the present disclosure.

[0018] The attached figures are labeled as follows: 1: Rectangular steel structure tower; 11: Rectangular component; 111: L-shaped component; 12: Transmission conductor; 13: Support component; 2: Magnetic field energy harvesting device for the under-rotating steel structure tower of AC transmission line; 21: Magnetic induction energy harvesting component; 211: Magnetic core; 212: Energy harvesting coil; 22: Energy harvesting circuit; 221: Voltage source; 222: Resistor; 223: Variable capacitor; 2231: Capacitor module; 22311: Capacitor; 22312: Switch; 2232: Control module; 22321: First counter; 22322: Second counter; 22323: First decoder; 22324: Second decoder; 224: Capacitor controller; 23: Energy storage unit. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0020] Figure 1 This is a schematic diagram of a magnetic field energy harvesting device for a circular steel structure tower under an AC transmission line, provided as an embodiment of this disclosure. See also... Figure 1 The device includes a magnetic induction energy harvesting component 21 and an energy harvesting circuit 22.

[0021] Figure 2 This is a schematic diagram of a magnetic induction energy harvesting component provided in an embodiment of this disclosure. See also: Figure 1 and Figure 2The magnetic induction energy harvesting component 21 includes a magnetic core 211 and an energy harvesting coil 212. The magnetic core 211 passes through the energy harvesting coil 212 and is disposed on the loop-shaped component 11, with both ends of the magnetic core 211 in contact with the loop-shaped component 11. The energy harvesting coil 212 is electrically connected to the energy harvesting circuit 22, which is a resonant circuit. The resonant circuit includes a resonant frequency adjustment component, which is used to dynamically adjust the resonant frequency of the energy harvesting circuit according to the change in the inductance value of the energy harvesting coil, so that the energy harvesting circuit is kept in a resonant state.

[0022] This disclosure provides a magnetic field energy harvesting device for a U-shaped steel structure tower under an AC transmission line. The device includes a magnetic induction energy harvesting component and an energy harvesting circuit. The magnetic induction energy harvesting component generates electricity using the magnetic flux density of the U-shaped structure, converting the magnetic field energy around the U-shaped structure into electrical energy, which is then output through the energy harvesting circuit. The energy harvesting circuit is a resonant circuit. Compared to using a conventional resistive load circuit, using a resonant circuit as the energy harvesting circuit can improve the output power of the energy harvesting circuit. The energy harvesting circuit includes a resonant frequency adjustment component. During energy harvesting, the inductance of the energy harvesting coil fluctuates. By setting the resonant frequency adjustment component, when the energy harvesting coil fluctuates, i.e., when the resonant circuit transitions to a non-resonant state, the resonant frequency of the resonant circuit is adjusted, causing the resonant circuit to return to a resonant state. By continuously maintaining the resonant circuit in a resonant state, the output power of the energy harvesting circuit can be kept at a high level, thereby improving the energy harvesting effect.

[0023] exist Figure 1 In the middle, the U-shaped steel structure tower 1 includes a U-shaped component 11, a power transmission conductor 12, and a support component 13. Figure 1 The shape of the spiral-shaped component in the example is only for illustration. In actual implementation, the spiral-shaped component can be any spiral-shaped structure, such as in... Figure 2 The image shows a different structure of the spiral-shaped component 11. Figure 2 The spiral-shaped component 11 is composed of four L-shaped components 111, which are connected by bolts. The spiral-shaped component 11 has a side length of 75mm, a thickness of 5.7mm, and a length of 1m.

[0024] In this embodiment, the magnetic core 211 comprises a plurality of stacked silicon steel magnetic chips. The silicon steel magnetic chips offer better energy extraction performance; however, the magnetic core 211 can also be formed from other materials.

[0025] In one example, the length of the magnetic core 211 does not exceed 1 meter, the cross-sectional shape of the silicon steel magnetic chip is rectangular, the cross-sectional size of the magnetic core 211 is 30mm×10mm, the total thickness is 10mm, and there are 40 pieces in total. The two ends of the magnetic core 211 are in contact with the two ends of the angle of the U-shaped steel respectively.

[0026] Of course, the above core dimensions are only an example, and the core dimensions can be set as needed. This disclosure does not limit this.

[0027] In this embodiment, the energy harvesting coil 212 is formed of energy harvesting wires, which are arranged in layers on the surface of the magnetic core 211, with the number of layers being 2 to 5. In this embodiment, using a layered winding method for the energy harvesting coil ensures better energy harvesting performance.

[0028] In one example, the energy harvesting coil 212 wound around the outside of the magnetic core 211 has 4000 turns of wire and the wire is enameled wire with a diameter of 0.5mm. The energy harvesting coil 212 is wound in layers, with 1000 turns in each layer, for a total of 4 layers.

[0029] Of course, the above-described configuration of the energy harvesting coil is only an example. In actual implementation, the number of turns, wire diameter, and number of wire layers in the energy harvesting coil can be set as needed, and this disclosure does not impose any restrictions on this.

[0030] In this embodiment of the disclosure, the number of magnetic induction energy harvesting components 21 on the spiral member 11 is multiple, and the multiple magnetic induction energy harvesting components 21 are set according to the magnitude of the magnetic flux density at each position on the spiral member 11.

[0031] In this embodiment of the disclosure, multiple magnetic induction energy harvesting components are provided simultaneously, which can further ensure the utilization rate of the magnetic field energy of the spiral member.

[0032] Figure 3 This is a schematic diagram of an energy harvesting circuit provided in an embodiment of this disclosure. See also... Figure 3 The energy harvesting circuit 22 includes: The circuit includes a voltage source 221, a resistor 222, and a resonant frequency adjustment component. The resonant frequency adjustment component includes a variable capacitor 223 and a capacitor controller 224. The voltage source 221, the resistor 222, the energy harvesting coil 212, and the variable capacitor 223 are connected in series. The capacitor controller 224 is used to determine the magnitude of the resonant frequency of the resonant circuit and the frequency of the voltage source 221, and to generate control commands to adjust the capacitance value of the variable capacitor 223.

[0033] In this embodiment of the disclosure, by setting a variable capacitor and a capacitor controller, when the inductance value of the energy harvesting coil fluctuates, the capacitance value of the variable capacitor can be controlled by the capacitor controller to ensure that the energy harvesting battery always maintains a resonant state.

[0034] In this embodiment of the disclosure, the capacitor controller 224 is a phase comparator; the phase comparator is used to compare the phase of the voltage u of the voltage source 221 with the phase of the current i in the series resonant circuit, and outputs a control signal io according to the phase of the voltage u of the voltage source 221 and the phase of the current i in the series resonant circuit to adjust the capacitance value of the variable capacitor 223.

[0035] In this embodiment of the disclosure, when the resonant circuit is in a resonant state , This is the resonant frequency of the resonant circuit. For the power extraction coil Sentiment value The capacitance value of the variable capacitor is given. At this point, the capacitive reactance of the resonant circuit is 0, the current phase in the resonant circuit is 0, and the output power of the resonant circuit is at its maximum. The inductance value of the energy harvesting coil increases with the capacitance value of the variable capacitor. If fluctuations occur and the resonant circuit needs to be maintained in a resonant state, the capacitor needs to be adjusted. When the inductor When the capacitance is reduced, the impedance of the resonant circuit becomes inductive, and the phase difference between the voltage and current across the voltage source is positive. In this case, the capacitance needs to be increased. When the reactance... When the capacitance is increased, the impedance of the resonant circuit becomes capacitive, and the phase difference between the voltage and current becomes negative. In this case, the capacitance needs to be reduced. By comparing the phase of the voltage and current using a phase comparator, the adjustment of the variable capacitor value can be determined to keep the resonant frequency of the resonant circuit the same as the frequency of the voltage source, thus maintaining the resonant circuit in a resonant state.

[0036] In this embodiment of the disclosure, the phase comparator operates as follows: when the phase of u leads the phase of i, io outputs a positive signal and the capacitance of the variable capacitor increases; when the phase of u lags behind the phase of i, io outputs a negative signal and the capacitance of the variable capacitor decreases.

[0037] Figure 4 This is a schematic diagram of a variable capacitor provided in an embodiment of this disclosure. See also... Figure 4 The variable capacitor 223 includes: The capacitor module 2231 includes multiple capacitors 22311 connected in parallel, and each capacitor 22311 is equipped with a switch 22312; The control module 2232 includes a first counter 22321, a second counter 22322, a first decoder 22323, and a second decoder 22324. The first counter 22321 is used to calculate the maximum number of the closed switch 22321, and the second counter 22322 is used to calculate the minimum number of the open switch 22312. The first decoder 22323 is used to receive the signal from the first counter 22321, and the second decoder 22324 is used to receive the signal from the second counter 22322. When the capacitor controller 224 releases a positive signal, the first counter 22321 releases a first electrical signal, controlling the switch 22312 to close and connecting the capacitor 22311 to the power extraction circuit. When the capacitor controller 224 releases a negative signal, the second counter 22322 releases a second electrical signal, controlling the switch 22312 to open and disconnecting the capacitor 22311 from the power extraction circuit.

[0038] In this embodiment of the disclosure, by setting a control module and a capacitor module, the technical effect of adjusting the capacitance value of the variable capacitor according to the io signal can be achieved.

[0039] exist Figure 4 In this embodiment, the capacitor module 2231 includes only 4 capacitors and 4 switches. During implementation, the number of capacitors and the number of switches can be set as needed, and this disclosure does not impose any restrictions on this.

[0040] In one example, using 8 switches numbered from 0, initially 4 switches are merged. At this point, the first counter counts to 3, and the second counter counts to 4. If a positive I / O signal is received, the switch of the 5th capacitor (switcher number 4) needs to be merged. The first counter becomes 4, and the second counter becomes 5. At this point, the first compiler starts working, receives the signal 100 from the first counter, and outputs 00010000. Now, only the switch of capacitor number 4 receives both the positive I / O signal and the positive decoder signal, and closes. If a negative I / O signal is received, the switch of the 4th capacitor (switcher number 3) needs to be opened. The first counter becomes 2, and the second counter becomes 3. At this point, the second compiler starts working, receives the signal 011 from the second counter, and outputs 11110111. Now, only the switch of number 3 receives both the negative I / O signal and the negative decoder signal, and the switch opens.

[0041] See you again Figure 1 In this embodiment of the present disclosure, the magnetic field energy harvesting device for the circular steel structure tower under the AC transmission line may further include an energy storage unit 23, which can be used to store the energy output by the energy harvesting circuit 22.

[0042] Figure 5A flowchart illustrating a method for installing a magnetic field energy harvesting device on a circular steel structure tower under an AC transmission line, as provided in this embodiment of the disclosure. See also... Figure 5 The method includes the following steps: S101. Obtain the structural parameters and permeability curves of the spiral-shaped component and the magnetic core.

[0043] In step S101, the structure of the spiral member is the same as that of the spiral member in a spiral steel structure tower in a real-world application scenario. For example, Figure 2 The structure of the spiral-shaped component.

[0044] S102. Establish a three-dimensional finite element module based on the structural parameters. The three-dimensional finite element model includes at least a spiral-shaped component and a power transmission line connected to the spiral-shaped component.

[0045] In step S102, when constructing the three-dimensional finite element model, the material of the transmission conductor is set to copper, the measured nonlinear permeability characteristic curve is imported, the surrounding medium is set to air, the solution boundary region is set to 5 times the model size, and the current value in the transmission conductor is set according to the stranded type of AC transmission line.

[0046] In one example, the transmission conductor material is set to copper, and the relative permeability is set to 0.99 based on the characteristics of copper core; the surrounding medium is set to air, and the relative permeability is set to 1; the solution boundary region is set to approximately 5 times the model size; an alternating current value is applied according to the direction of the transmission conductor's extended current; the current magnitude in the transmission conductor is 20~80A, for example, 80A; and the relative permeability curve is imported based on the Q235 angle steel model of the main material of the U-shaped steel.

[0047] S103. Simulate the three-dimensional finite element model to determine the magnetic flux density distribution of the spiral component. Determine the setting position of the magnetic induction energy harvesting component based on the magnetic flux density distribution. The magnetic induction energy harvesting component includes a magnetic core and an energy harvesting coil, with the magnetic core passing through the energy harvesting coil.

[0048] In one example, step S103 includes: Based on the magnitude of the magnetic flux density in the spiral member, one or more installation positions are determined, and the magnetic induction energy harvesting components are sequentially installed at the installation positions.

[0049] In this embodiment of the disclosure, the position of the magnetic induction energy harvesting component is set according to the magnitude of the magnetic flux density, which can maximize the energy harvesting efficiency.

[0050] In the embodiments disclosed herein, preliminary simulations revealed that the magnetic induction intensity of the loop-shaped component is much greater than that of air. Therefore, by setting a magnetic core at the intersection of the loop-shaped component to extract energy, the energy extraction efficiency can be maximized.

[0051] In this embodiment of the disclosure, in the finite element model, a magnetic core made of a high-permeability material is fixed at the intersection of the loop-shaped component. An energy harvesting coil is wound around the magnetic core. The coil uses 4000 turns of enameled wire with a diameter of 0.5 mm, wound in layers of 1000 turns each, for a total of four layers. Then, the measured magnetic track characteristic curve is imported into the finite element model to set its relative permeability.

[0052] S104. Simulate the magnetic core in a three-dimensional finite element model to determine the structure and arrangement of the magnetic core.

[0053] In one example, step S104 includes: In the three-dimensional finite element model, the tilt angle of the magnetic core, the number of silicon steel magnetic chips included in the magnetic core, and the magnitude of the current in the transmission line are used as single variables. Based on the magnitude of the magnetic flux density passing through the magnetic core, the tilt angle of the magnetic core and the number of silicon steel magnetic chips are determined, so as to determine the structure and arrangement of the magnetic core.

[0054] In this embodiment of the disclosure, further determining the optimal tilt angle and the number of silicon steel magnetic chips can ensure the energy harvesting efficiency of the magnetic core.

[0055] In this embodiment, keeping other conditions unchanged, the current of the transmission line is set to 20A, 40A, 60A, and 80A respectively. The calculated magnetic induction intensity at the core is 9.01mT, 17.53mT, 24.15mT, and 31.25mT respectively. It can be seen that although the magnetic induction intensity at the core is positively correlated with the current of the transmission line, there is a clear saturation condition. Keeping the above model unchanged, the tilt angle of the core is taken as 30°, 45°, 60°, and 70° respectively. The calculated magnetic induction intensity at the core is 34.56mT, 38.85mT, 35.03mT, and 34.17mT respectively. It can be seen that the appropriate tilt of the core has a certain influence on the magnetic induction intensity at the core, and the energy harvesting effect is best when the tilt angle is 45°.

[0056] In this embodiment of the disclosure, the specific method for calculating the magnetic flux Φ and magnetic induction intensity B of the energy harvesting coil is as follows:

[0057] Where f is the operating frequency of the AC transmission line, S is the cross-sectional area of ​​the magnetic core, and N is the number of turns of the secondary winding wire around the magnetic core.

[0058] S105. Construct an energy harvesting circuit, wherein the energy harvesting circuit is electrically connected to the energy harvesting coil, the energy harvesting circuit is a resonant circuit, and the resonant circuit includes a resonant frequency adjustment component, the resonant frequency adjustment component is used to dynamically adjust the resonant frequency of the energy harvesting circuit according to the change of the inductance value of the energy harvesting coil, so that the energy harvesting circuit is maintained in a resonant state.

[0059] In this embodiment, the power extraction circuit is a series resonant circuit. Overall, the series resonant circuit has a simpler structure compared to parallel resonant circuits. This simplification reduces manufacturing costs and maintenance difficulty. Furthermore, the series resonant circuit is highly adaptive, automatically adjusting its operating state according to load changes to maintain resonance. Simultaneously, the series resonant circuit exhibits good stability against external interference and load variations. It can provide the required power output more stably, reducing the risk of efficiency degradation or system failure due to external factors. Therefore, a series resonant circuit is chosen to achieve adaptive resonance.

[0060] Of course, the energy extraction circuit can also be other resonant circuits, and this disclosure does not limit it.

[0061] This disclosure also provides a method for setting up a magnetic field energy harvesting device for a loop-shaped steel structure tower under an AC transmission line. By constructing a three-dimensional finite element model and simulating the loop-shaped component, the magnetic flux density distribution within the loop-shaped component is determined, thereby determining the placement position of the magnetic core and ensuring that the magnetic flux density at the core position is maximized, thus ensuring energy harvesting efficiency. The magnetic core is then simulated again in the three-dimensional finite element model to determine the influence of the core's structure and placement method on its energy harvesting efficiency, determining the optimal core structure and placement method to further ensure the energy harvesting efficiency. Finally, an energy harvesting circuit is constructed. The energy harvesting circuit is a resonant circuit. By maintaining the energy harvesting circuit in a resonant state, the output power of the energy harvesting circuit is increased, further improving the energy harvesting efficiency. The method for setting up a magnetic field energy harvesting device for a loop-shaped steel structure tower under an AC transmission line provided by this invention can ensure a good energy harvesting effect and high energy harvesting efficiency.

[0062] Figure 6 A test data graph provided for an embodiment of this disclosure. See also: Figure 6 A purely resistive load model was established in ANSYS, where only the load resistor, 300Ω, was connected in series in the secondary winding circuit. The measured voltage waveform across the load stabilized as a sine wave with a power frequency of approximately 516.12mV after two oscillation cycles, and the calculated output power was 0.89mW. Then, a compensation circuit simulation based on the series resonance principle was performed, changing the secondary circuit of the energy harvesting coil to a series compensation circuit. The self-inductance of the secondary circuit of the energy harvesting coil was found to be 1.2554H in the field model, and the resonant capacitance was calculated to be 8.07μF. The solution termination time was set to 100ms (five power frequency cycles), with a step size of 1ms. The measured load voltage amplitude was 644.14mV, and the calculated output power was 1.38mW.

[0063] Depend on Figure 6It can be seen that after the secondary winding is changed from the pure resistive circuit to a series resonant circuit, the load voltage increases to approximately 1.25 times the original value, and the output power increases to 1.55 times the original value. Therefore, the series resonant circuit can be used as a compensation circuit for the magnetic field energy harvesting coil to improve the output power, thereby enhancing the energy harvesting effect.

[0064] Based on the above, a model was built in the laboratory to study the compensation circuit of the magnetic field energy harvesting coil based on series resonance. First, the simulation results were experimentally verified with the two leads of the coil open-circuited and a no-load test conducted. The output voltage was compared under different compensation capacitors. Analysis of the solution results showed that the voltage across the load changed with the capacitor. In this experiment, keeping the load at 80 ohms and the primary circuit current at 20A constant, the output voltage was 0.522V without the compensation capacitor. After adding the compensation capacitor, the maximum output voltage (i.e., at resonance) increased to 1.039V, 1.99 times that without the compensation capacitor. The power increased from 3.41mW to 13.49mW, 3.96 times the original, consistent with the simulation results. In practical applications, the adaptive series resonant circuit can effectively improve the output power of the energy harvesting coil, enhancing the magnetic field energy harvesting effect in U-shaped steel structures and ensuring a continuous and efficient power supply to the energy harvesting coil.

[0065] Therefore, the method for setting up a magnetic field energy harvesting device for a circular steel structure tower under an AC transmission line, as described in this invention, can effectively enhance the magnetic field energy harvesting effect of the circular steel structure under an AC transmission line. This method can further improve the output power of online magnetic field energy harvesting from transmission line towers.

[0066] This invention provides a method for enhancing magnetic field energy harvesting on circular steel structure towers under AC transmission lines, applicable to the field of online energy harvesting and power supply technology for AC transmission lines. Through the innovative technology of this invention, power supply problems can be effectively solved, maintenance costs reduced, and the stability and reliability of transmission lines improved.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A magnetic field energy harvesting device for a circular steel structure tower under an AC transmission line, characterized in that, include: Magnetic induction energy harvesting component and energy harvesting circuit; The magnetic induction energy harvesting component includes a magnetic core and an energy harvesting coil. The magnetic core passes through the energy harvesting coil and is disposed on a U-shaped component, with both ends of the magnetic core in contact with the U-shaped component. The energy harvesting coil is electrically connected to the energy harvesting circuit, which is a resonant circuit. The resonant circuit includes a resonant frequency adjustment component, which is used to dynamically adjust the resonant frequency of the energy harvesting circuit according to the change in the inductance value of the energy harvesting coil, so that the energy harvesting circuit remains in a resonant state. The energy harvesting circuit includes: A voltage source, a resistor, and a resonant frequency adjustment component are provided. The resonant frequency adjustment component includes a variable capacitor and a capacitor controller. The voltage source, the resistor, the energy harvesting coil, and the variable capacitor are connected in series. The capacitor controller is used to determine the magnitude of the resonant frequency of the resonant circuit and the frequency of the voltage source, and to generate control commands to adjust the capacitance value of the variable capacitor. The capacitor controller is a phase comparator; the phase comparator is used to compare the phase of the voltage source voltage and the phase of the current in the series resonant circuit, and outputs a control signal according to the phase of the voltage source voltage and the phase of the current in the series resonant circuit to adjust the capacitance value of the variable capacitor. The variable capacitor includes: A capacitor module, comprising multiple capacitors connected in parallel, each capacitor being configured with a switch; The control module includes a first counter, a second counter, a first decoder, and a second decoder. The first counter is used to calculate the maximum number of the closed switch, and the second counter is used to calculate the minimum number of the open switch. The first decoder receives the signal from the first counter, and the second decoder receives the signal from the second counter. When the capacitor controller releases a positive signal, the first counter releases a first electrical signal to control the switch to close and connect the capacitor to the power extraction circuit. When the capacitor controller releases a negative signal, the second counter releases a second electrical signal to control the switch to open and disconnect the capacitor from the power extraction circuit.

2. The magnetic field energy harvesting device for the under-circuit steel structure tower of AC transmission line according to claim 1, characterized in that, The number of magnetic induction energy harvesting components on the spiral-shaped component is multiple, and the multiple magnetic induction energy harvesting components are set according to the magnitude of the magnetic flux density at each position on the spiral-shaped component.

3. The magnetic field energy harvesting device for the under-circuit steel structure tower of AC transmission line according to claim 1, characterized in that, The magnetic core comprises multiple stacked silicon steel magnetic chips.

4. The magnetic field energy harvesting device for the under-rotating steel structure tower of an AC transmission line according to claim 1, characterized in that, The energy harvesting coil is formed by energy harvesting wires, which are arranged on the surface of the magnetic core in a layered manner, and the number of layers of the energy harvesting wires is 2 to 5.

5. A method for installing a magnetic field energy harvesting device on a circular steel structure tower under an AC transmission line, characterized in that, The method is applied to the magnetic field energy harvesting device for the circular steel structure tower under an AC transmission line as described in any one of claims 1 to 4, comprising: Obtain the structural parameters and permeability curves of the spiral-shaped component and the magnetic core; A three-dimensional finite element model is established based on the structural parameters. The three-dimensional finite element model includes at least a spiral-shaped component and a power transmission line connected to the spiral-shaped component. The magnetic flux density distribution of the spiral component is determined by simulating the three-dimensional finite element model. The setting position of the magnetic induction energy harvesting component is determined based on the magnetic flux density distribution. The magnetic induction energy harvesting component includes a magnetic core and an energy harvesting coil, and the magnetic core passes through the energy harvesting coil. The magnetic core is simulated in a three-dimensional finite element model to determine its structure and configuration. An energy harvesting circuit is constructed, which is electrically connected to the energy harvesting coil. The energy harvesting circuit is a resonant circuit, which includes a resonant frequency adjustment component. The resonant frequency adjustment component is used to dynamically adjust the resonant frequency of the energy harvesting circuit according to the change of the inductance value of the energy harvesting coil, so that the energy harvesting circuit is maintained in a resonant state.

6. The method for installing the magnetic field energy harvesting device on the circular steel structure tower under an AC transmission line according to claim 5, characterized in that, Determining the placement location of the magnetic induction energy harvesting component based on the magnetic flux density distribution includes: Based on the magnitude of the magnetic flux density in the spiral member, one or more installation positions are determined, and the magnetic induction energy harvesting components are sequentially installed at the installation positions.

7. The method for installing the magnetic field energy harvesting device on the circular steel structure tower under an AC transmission line according to claim 5, characterized in that, In a three-dimensional finite element model, the magnetic core is simulated to determine its structure and configuration, including: In the three-dimensional finite element model, the tilt angle of the magnetic core, the number of silicon steel magnetic chips included in the magnetic core, and the magnitude of the current in the transmission line are used as single variables. Based on the magnitude of the magnetic flux density passing through the magnetic core, the tilt angle of the magnetic core and the number of silicon steel magnetic chips are determined, so as to determine the structure and arrangement of the magnetic core.

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