Magnetic field energy taking device for concentric-square-shaped steel structure tower under alternating-current transmission line and setting method of magnetic field energy taking device

Abstract

The invention provides a concentric-square-shaped steel structure tower magnetic field energy taking device under an alternating-current power transmission line and a setting method of the concentric-square-shaped steel structure tower magnetic field energy taking device. The device comprises a magnetic induction energy taking assembly and an energy taking circuit, the magnetic induction energy taking assembly comprises a magnetic core and an energy taking coil, the magnetic core penetrates through the energy taking coil and is arranged on a concentric-square-shaped piece, and the two ends of the magnetic core make contact with the concentric-square-shaped piece; the energy taking coil is electrically connected with the energy taking circuit, the energy taking circuit is a resonant circuit, the resonant circuit comprises a resonant frequency adjusting assembly, and the resonant frequency adjusting assembly is used for dynamically adjusting the resonant frequency of the energy taking circuit according to the change of the inductance value of the energy taking coil, so that the energy taking circuit is kept in a resonant state. The magnetic field energy of the concentric-square-shaped steel structure tower can be converted into electric energy, and meanwhile the energy conversion efficiency can be further improved.

Description

Technical Field

[0001] The invention relates to the technical field of magnetic field energy harvesting of an AC transmission line tower, and in particular to a magnetic field energy harvesting device for a round-shaped steel structure tower under an AC transmission line and a setting method thereof. Background Art

[0002] High-voltage transmission lines are often affected by various natural and human factors. In order to ensure the safe operation of transmission lines, monitoring equipment needs to be installed on the transmission lines, which places high demands on the economy and stability of their energy supply systems. However, since the towers of transmission lines are widely distributed and in complex field environments, power supply issues have become the main factor restricting the development of online monitoring devices for transmission lines.

[0003] The magnetic field energy around the transmission line towers remains relatively stable. In theory, we can use these magnetic fields to obtain energy online. How to maximize the use of the magnetic field energy around the transmission line towers for the monitoring equipment to function has become a top priority. Summary of the invention

[0004] The invention provides a magnetic field energy harvesting device for a round-shaped steel structure tower under an AC transmission line and a setting method thereof, which can generate electricity by utilizing the magnetic field energy of the round-shaped 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, wherein the magnetic core passes through the energy harvesting coil, the magnetic core is arranged on a circular piece, and both ends of the magnetic core are in contact with the circular piece; the energy harvesting coil is electrically connected to the energy harvesting circuit, and the energy harvesting circuit is a resonant circuit, wherein the resonant circuit includes a resonant frequency adjustment component, and 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 as to keep the energy harvesting circuit in a resonant state.

[0006] Optionally, the energy acquisition circuit includes: A voltage source, a resistor and a resonant frequency adjustment component, wherein the resonant frequency adjustment component includes a variable capacitor and a capacitance controller, wherein the voltage source, the resistor, the energy extraction coil and the variable capacitor are connected in series, and the capacitance 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 a control instruction 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 output 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 comprises: A capacitor module includes a plurality of capacitors connected in parallel, each capacitor being provided with a switch; A control module, 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 closed switches, and the second counter is used to calculate the minimum number of open switches; the first decoder is used to receive a signal from the first counter, and the second decoder is used to receive a 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 an energy-taking 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 energy-taking circuit.

[0009] Optionally, there are multiple magnetic induction energy harvesting components on the circular piece, and the multiple magnetic induction energy harvesting components are arranged according to the magnitude of the magnetic flux density at each position on the circular piece.

[0010] Optionally, the magnetic core includes a plurality of stacked silicon steel magnetic core pieces.

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

[0012] On the other hand, a method for setting a magnetic field energy harvesting device for a circular steel structure tower under an AC transmission line is provided, the method being applied to the magnetic field energy harvesting device for a circular steel structure tower under an AC transmission line as described in any one of the above items, comprising: Obtain structural parameters and magnetic permeability curves of the circular piece and magnetic core; Establishing a three-dimensional finite element module according to the structural parameters, wherein the three-dimensional finite element model at least includes a circular piece and a transmission wire connected to the circular piece; Simulating the three-dimensional finite element model to determine the magnetic flux density distribution of the circular piece, and determining the setting position of the magnetic induction energy acquisition component according to the magnetic flux density distribution, wherein the magnetic induction energy acquisition component includes a magnetic core and an energy acquisition coil, and the magnetic core passes through the energy acquisition coil; In the three-dimensional finite element model, the magnetic core is simulated to determine the structure and setting method of the magnetic core; An energy harvesting circuit is constructed, wherein the energy harvesting circuit is electrically connected to the energy harvesting coil, wherein the energy harvesting circuit is a resonant circuit, wherein the resonant circuit includes a resonant frequency adjustment component, wherein the resonant frequency adjustment component is used to dynamically adjust the resonant frequency of the energy harvesting circuit according to changes in the inductance of the energy harvesting coil, so as to maintain the energy harvesting circuit in a resonant state.

[0013] Optionally, determining the location of the magnetic induction energy harvesting component according to the magnetic flux density distribution includes: One or more setting positions are determined according to the magnitude of the magnetic flux density in the circular piece, and the magnetic induction energy acquisition components are sequentially set at the setting positions.

[0014] Optionally, the magnetic core is simulated in a three-dimensional finite element model to determine the structure and arrangement of the magnetic core, including: In the three-dimensional finite element model, the inclination angle of the magnetic core, the number of silicon steel magnetic core pieces included in the magnetic core and the current in the transmission line are used as single variables. According to the size of the magnetic flux density passing through the magnetic core, the inclination angle of the magnetic core and the number of silicon steel magnetic core pieces are determined to determine the structure and setting method of the magnetic core.

[0015] The technical solution provided by the embodiments of the present disclosure has the following beneficial effects: In an embodiment of the present disclosure, a magnetic field energy harvesting device for a circular steel structure tower under an AC transmission line is provided, the device comprising a magnetic induction energy harvesting component and an energy harvesting circuit. The magnetic induction energy harvesting component generates electricity by using the magnetic flux density of the circular piece through the principle of magnetoelectricity, converts the magnetic field energy around the circular piece into electrical energy, and outputs the electrical energy through the energy harvesting circuit. The energy harvesting circuit is a resonant circuit. By using the resonant circuit as the energy harvesting circuit, the output power of the energy harvesting circuit can be improved compared to using a conventional resistive load circuit as the energy harvesting circuit. The energy harvesting circuit includes a resonant frequency adjustment component. During the energy harvesting process, the inductance value of the energy harvesting coil of the resonant circuit will fluctuate. By setting the resonant frequency adjustment component, when the energy harvesting coil fluctuates, that is, when the resonant circuit is transformed into a non-resonant state, the resonant frequency of the resonant circuit is adjusted to make the resonant circuit transform back into a resonant state. By keeping the resonant circuit in a resonant state, it is possible to ensure that the output power of the energy harvesting circuit is always maintained at a high level, thereby improving the energy harvesting effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A schematic diagram of the structure of a magnetic field energy harvesting device for a roundabout steel structure tower under an AC transmission line provided in an embodiment of the present disclosure; Figure 2 A schematic diagram of the structure of a magnetic induction energy harvesting component provided in an embodiment of the present disclosure; Figure 3 A schematic diagram of the structure of an energy extraction circuit provided in an embodiment of the present disclosure; Figure 4 A schematic diagram of the structure of a variable capacitor provided in an embodiment of the present disclosure; Figure 5 A method flow chart of a method for setting a magnetic field energy harvesting device of a round-shaped steel structure tower under an AC transmission line provided in an embodiment of the present disclosure; Figure 6 An experimental data graph provided for an embodiment of the present disclosure.

[0018] The reference numerals are as follows: 1: round steel structure tower; 11: round piece; 111: L-shaped piece; 12: transmission line; 13: support piece; 2: Magnetic field energy harvesting device of circular steel structure tower under 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 DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Figure 1 This is a schematic diagram of the structure of a magnetic field energy harvesting device for a circular steel structure tower under an AC transmission line provided by an embodiment of the present disclosure. 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 the structure of a magnetic induction energy harvesting component provided by an embodiment of the present disclosure. 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. The magnetic core 211 is arranged on the circular piece 11, and both ends of the magnetic core 211 are in contact with the circular piece 11. The energy harvesting coil 212 is electrically connected to the energy harvesting circuit 22. The energy harvesting circuit 22 is a resonant circuit. 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 remains in a resonant state.

[0022] In an embodiment of the present disclosure, a magnetic field energy harvesting device for a circular steel structure tower under an AC transmission line is provided, the device comprising a magnetic induction energy harvesting component and an energy harvesting circuit. The magnetic induction energy harvesting component generates electricity by using the magnetic flux density of the circular piece through the principle of magnetoelectricity, converts the magnetic field energy around the circular piece into electrical energy, and outputs the electrical energy through the energy harvesting circuit. The energy harvesting circuit is a resonant circuit. By using the resonant circuit as the energy harvesting circuit, the output power of the energy harvesting circuit can be improved compared to using a conventional resistive load circuit as the energy harvesting circuit. The energy harvesting circuit includes a resonant frequency adjustment component. During the energy harvesting process, the inductance value of the energy harvesting coil of the resonant circuit will fluctuate. By setting the resonant frequency adjustment component, when the energy harvesting coil fluctuates, that is, when the resonant circuit is transformed into a non-resonant state, the resonant frequency of the resonant circuit is adjusted to make the resonant circuit transform back into a resonant state. By keeping the resonant circuit in a resonant state, it is possible to ensure that the output power of the energy harvesting circuit is always maintained at a high level, thereby improving the energy harvesting effect.

[0023] exist Figure 1 In the embodiment, the round-shaped steel structure tower 1 comprises a round-shaped member 11, a transmission line 12 and a support member 13. Figure 1 The shape of the loop-shaped piece in the embodiment is only an example. In the actual implementation process, the loop-shaped piece can be any loop-shaped structure, such as Figure 2 In FIG. 1 , another structure of the circular piece 11 is shown. Figure 2 The circular piece 11 is composed of four L-shaped pieces 111, and the multiple L-shaped pieces 111 are connected by bolts. The circular piece 11 has a cross-sectional side length of 75 mm, a thickness of 5.7 mm, and a length of 1 m.

[0024] In the embodiment of the present disclosure, the magnetic core 211 includes a plurality of stacked silicon steel magnetic core pieces, wherein the silicon steel magnetic core pieces have a better energy extraction effect. Of course, the magnetic core 211 can also be formed of 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 core piece 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 respectively in contact with the two ends of the intersection of the circular steel.

[0026] Of course, the above size of the magnetic core is only used as an example, and the size of the magnetic core can be set as needed, and the present disclosure does not limit this.

[0027] In the embodiment of the present disclosure, the energy collection coil 212 is formed by an energy collection wire, which is arranged on the surface of the magnetic core 211 in a layered manner, and the number of layers of the energy collection wire is 2 to 5. In the embodiment of the present disclosure, the energy collection coil is arranged in a layered manner, which can ensure that the energy collection effect of the energy collection coil is better.

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

[0029] Of course, the above configuration of the energy extraction coil is only an example. In actual implementation, the number of turns, wire diameter, number of wire layers, etc. in the energy extraction coil can be set as needed, and the present disclosure does not limit this.

[0030] In the disclosed embodiment, there are multiple magnetic induction energy harvesting components 21 on the circular member 11 , and the multiple magnetic induction energy harvesting components 21 are arranged according to the magnitude of the magnetic flux density at each position on the circular member 11 .

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

[0032] Figure 3 A schematic diagram of a power-harvesting circuit according to an embodiment of the present disclosure. Figure 3 , the energy taking circuit 22 comprises: A voltage source 221, a resistor 222 and a resonant frequency adjustment component, wherein the resonant frequency adjustment component includes a variable capacitor 223 and a capacitor controller 224. The voltage source 221, the resistor 222, the energy extraction 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 a control instruction to adjust the capacitance value of the variable capacitor 223.

[0033] In the embodiment of the present disclosure, by setting a variable capacitor and a capacitance controller, when the inductance value of the energy extraction coil fluctuates, the capacitance value of the variable capacitor is controlled by the capacitance controller to ensure that the energy extraction battery is always maintained in a resonant state.

[0034] In the embodiment of the present 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 and the phase of the current i in the series resonant circuit, and output the 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 the embodiment of the present disclosure, when the resonant circuit is in a resonant state, , is the resonant frequency of the resonant circuit, The power of the energy-taking coil Sensitivity value, is the capacitance value of the variable capacitor. At this time, 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 maximum. If the resonant circuit needs to be kept in a resonant state, the capacitor needs to be adjusted. When the inductor When the reactance decreases, the impedance of the resonant circuit becomes inductive, and the voltage and current phase difference on both sides of the voltage source is positive. At this time, the capacitance needs to be increased. When the voltage increases, the impedance of the resonant circuit becomes capacitive, and the phase difference between the voltage and current is negative. At this time, the capacitance needs to be reduced. By comparing the phase of the voltage and current through the phase comparator, it is determined how to adjust the capacitance value of the variable capacitor, so that the resonant frequency of the resonant circuit can be kept the same as the frequency of the voltage source, so that the resonant circuit is always maintained in a resonant state.

[0036] In the embodiment of the present disclosure, the working principle of the phase comparator is as follows: when the phase of u is ahead of 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 A schematic diagram of the structure of a variable capacitor provided by an embodiment of the present disclosure. Figure 4 , the variable capacitor 223 comprises: The capacitor module 2231 includes a plurality of capacitors 22311 connected in parallel, and each capacitor 22311 is configured with a switch 22312; A control module 2232, the control module 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 closed switches 22321, and the second counter 22322 is used to calculate the minimum number of open switches 22312; the first decoder 22323 is used to receive the signal of the first counter 22321, and the second decoder 22324 is used to receive the signal of the second counter 22322; when the capacitor controller 224 releases a positive signal, the first counter 22321 releases a first electrical signal, controls the switch 22312 to close, and connects the capacitor 22311 to the energy-taking circuit; when the capacitor controller 224 releases a negative signal, the second counter 22322 releases a second electrical signal, controls the switch 22312 to open, and disconnects the capacitor 22311 from the energy-taking circuit.

[0038] In the embodiment of the present disclosure, by setting a control module and a capacitance 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 the 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 the present disclosure does not limit this.

[0040] In one example, 8 switches are numbered starting from 0, and 4 switches are merged in the initial stage. At this time, the first counter counts 3 and the second counter counts 4. If a positive signal is transmitted to io, the switch of the fifth capacitor (switch number is 4) needs to be merged. The number of the first counter becomes 4, and the number of the second counter becomes 5. At this time, the first compiler starts working, receives the signal 100 of the first counter, and outputs 00010000. At this time, only the switch of the capacitor numbered 4 receives the positive signal of io and the positive signal of the decoder at the same time, and is closed. If a negative signal is transmitted to io, the switch of the fourth capacitor (switch number is 3) needs to be disconnected. The first counter becomes 2, and the second counter becomes 3. At this time, the second compiler starts working, receives the signal 011 of the second counter, and outputs 11110111. At this time, only the switch numbered 3 receives the negative signal of io and the negative signal of the second decoder at the same time, and the switch is disconnected.

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

[0042] Figure 5A method flow chart of a method for setting a magnetic field energy harvesting device for a circular steel structure tower under an AC transmission line provided by an embodiment of the present disclosure. Figure 5 The method steps include: S101, obtaining structural parameters and magnetic permeability curve of the circular piece and the magnetic core.

[0043] In step S101, the structure of the circular piece is the structure of the circular piece in the circular steel structure tower in the actual application scenario. Figure 2 The structure of the circular piece in.

[0044] S102: Establish a three-dimensional finite element module according to the structural parameters, wherein the three-dimensional finite element model at least includes a circular member and a transmission line connected to the circular member.

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

[0046] In one example, the material of the transmission line is set to copper, and the relative magnetic permeability is set to 0.99 according to the characteristics of the copper core; the surrounding medium is set to air, the relative magnetic permeability is set to 1, and the solution boundary area is set to about 5 times the model size. The AC current value is loaded in the extension direction of the transmission line current. The current in the transmission line is 20~80A, for example, 80A. At the same time, the relative magnetic permeability curve is imported according to the main material Q235 angle steel model of the circular steel.

[0047] S103, simulating the three-dimensional finite element model to determine the magnetic flux density distribution of the circular piece, and determining the setting position of the magnetic induction energy acquisition component according to the magnetic flux density distribution, wherein the magnetic induction energy acquisition component includes a magnetic core and an energy acquisition coil, and the magnetic core passes through the energy acquisition coil.

[0048] In one example, step S103 includes: One or more setting positions are determined according to the magnitude of the magnetic flux density in the circular piece, and the magnetic induction energy acquisition components are sequentially set at the setting positions.

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

[0050] In the embodiment of the present disclosure, after preliminary simulation, it was found that the magnetic induction intensity of the toroidal piece is much greater than that of the air. Therefore, by arranging a magnetic core for energy extraction at the intersection of the toroidal piece, the energy extraction efficiency can be maximized.

[0051] In the embodiment of the present disclosure, in the finite element model, a magnetic core of a high magnetic permeability material is fixed at the intersection of the round-shaped piece, and the energy taking coil is wound on the magnetic core. The number of turns of the coil is selected to be 4000 turns, and the wire diameter is 0.5mm. The layer winding method is adopted, and each layer is wound with 1000 turns, and a total of 4 layers are wound. Then, the measured magnetic track characteristic curve is imported into the finite element model to set its relative magnetic permeability.

[0052] S104. In a three-dimensional finite element model, simulate the magnetic core to determine the structure and setting method of the magnetic core.

[0053] In one example, step S104 includes: In the three-dimensional finite element model, the inclination angle of the magnetic core, the number of silicon steel magnetic core pieces included in the magnetic core and the current in the transmission line are used as single variables. According to the size of the magnetic flux density passing through the magnetic core, the inclination angle of the magnetic core and the number of silicon steel magnetic core pieces are determined to determine the structure and setting method of the magnetic core.

[0054] In the disclosed embodiment, further determining the optimal tilt angle and the number of silicon steel core pieces can ensure the energy extraction efficiency of the magnetic core.

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

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

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

[0058] S105. Construct an energy harvesting circuit, wherein the energy harvesting circuit is electrically connected to the energy harvesting coil, and the energy harvesting circuit is a resonant circuit. The resonant circuit includes a resonant frequency adjustment component, and 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 the disclosed embodiment, the energy extraction circuit is a series resonant circuit. Overall, the series resonant circuit has a relatively simple circuit structure compared to circuits such as parallel resonance. This simplification can reduce manufacturing costs and maintenance difficulties. In addition, the series resonant circuit has strong adaptability, and the series resonant circuit can automatically adjust the working state according to changes in the load to maintain the resonant condition. At the same time, the series resonant circuit has good stability to external interference and load changes. It can provide the required power output more stably and reduce the risk of efficiency reduction or system failure due to external factors. Therefore, a series resonant circuit is selected to achieve adaptive resonance.

[0060] Of course, the energy harvesting circuit may also be other resonant circuits, and the present disclosure is not limited to this.

[0061] In the disclosed embodiment, a method for setting a magnetic field energy harvesting device for a circular steel structure tower under an AC transmission line is also provided. By constructing a three-dimensional finite element model, simulating the circular piece, and determining the magnetic flux density distribution in the circular piece, the setting position of the magnetic core is determined to ensure that the magnetic flux density at the position of the magnetic core is the maximum, thereby ensuring the energy harvesting effect. The magnetic core is simulated again in the three-dimensional finite element model to determine the influence of the structure and setting method of the magnetic core on the energy harvesting effect of the magnetic core, and the optimal magnetic core structure and setting method of the magnetic core are determined to further ensure the energy harvesting effect of the magnetic core. Finally, an energy harvesting circuit is constructed, and 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, and the energy harvesting effect is further improved. The method for setting a magnetic field energy harvesting device for a circular steel structure tower under an AC transmission line provided by the present invention can ensure that the energy harvesting effect of the magnetic field energy harvesting device of the circular steel structure tower under the AC transmission line is relatively good and the energy harvesting efficiency is high.

[0062] Figure 6 This is a test data diagram provided by the embodiment of the present disclosure. Figure 6 , a pure resistance load model is established in ANSYS, that is, only the load resistor is connected in series in the secondary winding loop, and the load resistor is set to 300Ω. The waveform of the voltage across the load is measured to be basically stable as a sine wave with a frequency of the power frequency after two cycles of oscillation, with an amplitude of about 516.12mV, and the calculated output power is 0.89mW. Then the compensation circuit simulation based on the series resonance principle is carried out, and the secondary circuit of the energy extraction coil is changed to a series compensation circuit. In the field model, the self-inductance of the secondary circuit of the energy extraction coil is obtained to be 1.2554H, and the resonant capacitance value is obtained to be 8.07μF. The solution termination time is set to 100ms, that is, five power frequency cycles, and the step size is 1ms for solution. The load voltage amplitude is measured to be 644.14mV, and the calculated output power is 1.38mW.

[0063] Depend on Figure 6It can be seen that after the secondary winding is changed from the above pure resistance circuit to a series resonant circuit, the load voltage is increased to about 1.25 times the original, and the output power is increased to 1.55 times the original. It can be seen that the series resonant circuit can be used as a compensation circuit for the magnetic field energy harvesting coil to increase the output power, and the energy harvesting effect can be improved.

[0064] On the basis of 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 conclusion was experimentally verified. The two outgoing lines of the coil were open and a no-load test was performed; the output voltage under different compensation capacitors was compared. The analysis and solution results show that when the capacitance changes, the voltage on the load will also change; in this experiment, the load is kept at 80 ohms, the primary loop current is 20A, and the output voltage is 0.522V without the compensation capacitor. After adding the compensation capacitor, the maximum output value (that is, when resonance occurs) is 1.039V, which is 1.99 times that of the case without the compensation capacitor. The power increased from 3.41mW to 13.49mW, which is 3.96 times the original, which is consistent with the simulation conclusion. In practical applications, the adaptive series resonant circuit can effectively improve the output power of the energy harvesting coil. The magnetic field energy harvesting effect in the round steel structure is enhanced to ensure the continuous and efficient power supply of 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 described in the present invention can effectively enhance the magnetic field energy harvesting effect of the circular steel structure under the AC line. This method can further improve the output power of online magnetic field energy harvesting of the transmission line tower.

[0066] The present invention provides a method for enhancing magnetic field energy extraction of a circular steel structure tower under an AC transmission line, which is applicable to the field of online energy extraction and power supply technology for AC transmission lines. Through the innovative technology of the present invention, power supply problems can be effectively solved, maintenance costs can be reduced, and the stability and reliability of transmission lines can be improved.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions 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, wherein the magnetic core passes through the energy harvesting coil, the magnetic core is arranged on a circular piece, and both ends of the magnetic core are in contact with the circular piece; the energy harvesting coil is electrically connected to the energy harvesting circuit, and the energy harvesting circuit is a resonant circuit, wherein the resonant circuit includes a resonant frequency adjustment component, and 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 as to keep the energy harvesting circuit in a resonant state.

2. The magnetic field energy harvesting device for the circular steel structure tower under the AC transmission line according to claim 1 is characterized in that: The energy taking circuit comprises: A voltage source, a resistor and a resonant frequency adjustment component, wherein the resonant frequency adjustment component includes a variable capacitor and a capacitance controller, wherein the voltage source, the resistor, the energy extraction coil and the variable capacitor are connected in series, and the capacitance 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 a control instruction to adjust the capacitance value of the variable capacitor.

3. The magnetic field energy harvesting device for the circular steel structure tower under the AC transmission line according to claim 2 is characterized in that: 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 output 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.

4. The magnetic field energy harvesting device for the circular steel structure tower under the AC transmission line according to claim 3 is characterized in that: The variable capacitor comprises: A capacitor module includes a plurality of capacitors connected in parallel, each capacitor being provided with a switch; A control module, 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 closed switches, and the second counter is used to calculate the minimum number of open switches; the first decoder is used to receive a signal from the first counter, and the second decoder is used to receive a 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 an energy-taking 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 energy-taking circuit.

5. The magnetic field energy harvesting device for the circular steel structure tower under the AC transmission line according to claim 1 is characterized in that: There are multiple magnetic induction energy harvesting components on the circular piece, and the multiple magnetic induction energy harvesting components are arranged according to the magnitude of the magnetic flux density at each position on the circular piece.

6. The magnetic field energy harvesting device for the circular steel structure tower under the AC transmission line according to claim 1 is characterized in that: The magnetic core includes a plurality of stacked silicon steel magnetic core pieces.

7. The magnetic field energy harvesting device for the circular steel structure tower under the AC power transmission line according to claim 1 is characterized in that: The energy collection coil is formed by an energy collection wire, and the energy collection wire is arranged on the surface of the magnetic core in a layered manner, and the number of layers of the energy collection wire is 2 to 5 layers.

8. A method for setting a magnetic field energy harvesting device for a circular steel structure tower under an AC transmission line, characterized in that: The method is applied to the magnetic field energy harvesting device of the circular steel structure tower under the AC transmission line as claimed in any one of claims 1 to 7, comprising: Obtain structural parameters and magnetic permeability curves of the circular piece and magnetic core; Establishing a three-dimensional finite element module according to the structural parameters, wherein the three-dimensional finite element model at least includes a circular piece and a transmission wire connected to the circular piece; Simulating the three-dimensional finite element model to determine the magnetic flux density distribution of the circular piece, and determining the setting position of the magnetic induction energy acquisition component according to the magnetic flux density distribution, wherein the magnetic induction energy acquisition component includes a magnetic core and an energy acquisition coil, and the magnetic core passes through the energy acquisition coil; In the three-dimensional finite element model, the magnetic core is simulated to determine the structure and setting method of the magnetic core; An energy harvesting circuit is constructed, wherein the energy harvesting circuit is electrically connected to the energy harvesting coil, wherein the energy harvesting circuit is a resonant circuit, wherein the resonant circuit includes a resonant frequency adjustment component, wherein the resonant frequency adjustment component is used to dynamically adjust the resonant frequency of the energy harvesting circuit according to changes in the inductance of the energy harvesting coil, so as to maintain the energy harvesting circuit in a resonant state.

9. The method for obtaining energy from magnetic field of a circular steel tower under an AC power transmission line according to claim 8, characterized in that: Determining the location of the magnetic induction energy harvesting component according to the magnetic flux density distribution includes: One or more setting positions are determined according to the magnitude of the magnetic flux density in the circular piece, and the magnetic induction energy acquisition components are sequentially set at the setting positions.

10. The method for obtaining energy from magnetic field of a circular steel structure tower under an AC power transmission line according to claim 8, characterized in that: In the 3D finite element model, the core is simulated to determine the structure and setting of the core, including: In the three-dimensional finite element model, the inclination angle of the magnetic core, the number of silicon steel magnetic core pieces included in the magnetic core and the current in the transmission line are used as single variables. According to the size of the magnetic flux density passing through the magnetic core, the inclination angle of the magnetic core and the number of silicon steel magnetic core pieces are determined to determine the structure and setting method of the magnetic core.

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