A low frequency high power feeding device

Abstract

The invention provides a low-frequency high-power feeding device, which relates to the technical field of low-frequency electromagnetic communication. The device comprises a first impedance converter, a double-layer feed cage and a second impedance converter which are sequentially connected through a first wire; the transformation ratio of the first impedance converter is a fixed value, the double-layer feed cage comprises a frame, an installation space is formed in the frame, and a first feed line ring and a second feed line ring are arranged in the installation space; the first feed line ring comprises a plurality of first wires arranged along the axial direction; the second feed line ring comprises a plurality of second wires arranged along the axial direction; the double-layer feed cage of the invention adopts a plurality of first wires and a plurality of second wires to form a coaxial double-layer cage structure, increases an effective current-carrying cross-section, improves transmission efficiency, has no leakage, can withstand a large current and withstand a certain voltage, realizes the matching of a transmitter output impedance and an antenna impedance with a characteristic impedance of the double-layer feed cage through an impedance converter, and realizes long-distance low-loss transmission of a low-frequency high-power signal from a transmitter to a tuning device.

Description

Technical Field

[0001] The present invention relates to the technical field of low-frequency communication, and in particular to a low-frequency high-power feeding device. Background Art

[0002] Low-frequency (10kHz-100kHz) radio propagates in the Earth-ionosphere waveguide. It has stable propagation, is not affected by nuclear explosions and ionosphere disturbances, has low propagation attenuation in the atmosphere (-3dB / 1000km), can penetrate deeper seawater and the earth, and is suitable for long-distance underwater communication and ground-penetrating communication. Low-frequency fixed transmitting stations usually have a power of up to 200kW-2000kW, and mainly consist of high-power low-frequency transmitters, tuning devices and antenna systems. The very low frequency transmitter realizes very low frequency small signal power amplification, the tuning device realizes impedance matching of the antenna loop, and the antenna realizes the spatial radiation of the modulated high-power carrier very low frequency signal.

[0003] The feeding of the low-frequency fixed transmitter antenna system is divided into two parts: high-voltage feeder and low-voltage feeder. The low-voltage feeder is used to transfer low-frequency power from the high-power transmitter to the tuning device. Usually, the transmission power of the low-voltage feeder is as high as 500kW, the current is as high as 1000A, the voltage is as high as 20kV, and the transmission distance is hundreds of meters to thousands of meters. If a general high-voltage cable is used to transmit low-frequency and high-power signals, the distributed capacitance is large (0.15μF / km) and the dielectric loss is high, which will cause a significant loss of transmission power. The large-diameter feeder has a small transmission loss, but the volume is large and the price is expensive. Ordinary high-voltage cables and feeders are not suitable for low-frequency and high-power transmission over thousands of meters. Therefore, the traditional single-layer feeder structure has problems such as large energy loss and susceptibility to external interference when transmitting high-power signals, and cannot meet the needs of low-loss transmission of low-frequency and high-power signals. Therefore, a new type of high-power and low-loss transmission device is urgently needed to solve these problems. Summary of the invention

[0004] The disclosed embodiment provides a low-frequency high-power feeding method and device, including a double-layer feeding cage and two impedance converters. The double-layer feeding cage uses a plurality of first conductors and a plurality of second conductors to form a coaxial double-layer cage structure, which increases the effective current-carrying cross-section, improves the transmission efficiency, has no leakage, and can withstand a large current and a certain voltage. The impedance converter is used to match the transmitter output impedance and antenna impedance with the characteristic impedance of the double-layer feeding cage, realize the long-distance low-loss transmission of low-frequency high-power signals from the transmitter to the tuning device, and meet the transmission requirements of 500m-1000m for 200kW-2000kW transmitter signals.

[0005] To achieve the above object, according to a first aspect of the present invention, a first impedance transformer, a double-layer feed cage, and a second impedance transformer connected in sequence through a first wire are provided; the first impedance transformer is arranged at the connection end between the double-layer feed cage and the low-frequency transmitter, and the transformation ratio of the first impedance transformer is a fixed value, and is used to impedance match the impedance between the double-layer feed cage and the low-frequency transmitter at a fixed ratio;

[0006] The double-layer feed cage includes a frame, an installation space is formed in the frame, and a first feeder ring and a second feeder ring are arranged in the installation space; wherein the first feeder ring is arranged in the second feeder ring, the outer peripheral wall of the second feeder ring is tangent to the inner wall of the frame, and the first feeder ring and the second feeder ring are fixedly connected to the frame through a mounting frame; the first feeder ring includes a plurality of first conductors arranged along the axial direction, and the plurality of first conductors are connected by a first loop wire to form a cylindrical structure; the second feeder ring includes a plurality of second conductors arranged along the axial direction, and the plurality of first conductors are connected by a second loop wire to form a cylindrical structure;

[0007] The second impedance transformer is arranged at the connection end between the double-layer feeding cage and the tuning device; the transformation ratio of the second impedance transformer is a non-fixed value, so as to adjust the transformation ratio so that the impedance between the double-layer feeding cage and the tuning device can be matched under different working conditions.

[0008] As described in the low-frequency high-power feeding device, the first feeder ring and the second feeder ring are coaxially arranged.

[0009] As described in the low-frequency high-power feeding device, the number of the first conductors is determined as follows:

[0010] ;

[0011] in, is the number of first wires; is the total current carrying capacity; is the current carrying capacity per unit area; is the radius of the first conductor; is the skin depth.

[0012] As described in the low-frequency high-power feeding device, the number of the second conductors is determined as follows:

[0013] ;

[0014] ;

[0015] in, is the number of the second conductor; is the conductor ground current; is the first conductor current; is the radius of the second feeder loop; Equivalent radius of the second feeder loop.

[0016] As described in the low-frequency high-power feeding device, the mounting frame is an insulating support assembly, and the insulating support assembly includes a plurality of capped rod-shaped insulators.

[0017] As described in the low-frequency high-power feeding device, the first conductor, the second conductor and the first loop wire are made of copper.

[0018] As in the low-frequency high-power feeding device, the material of the second loop wire includes copper or steel.

[0019] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0020] The low-frequency high-power feeding device provided by the present invention is composed of a coaxial double-layer structure composed of multiple first conductors and multiple second conductors. The first feeder ring and the second feeder ring are both composed of multiple conductors. Compared with the general coaxial high-voltage cable, the feeder composed of multiple conductors has low loss and strong wind resistance. Compared with the feeder tube, it is light in weight and has a suitable price. Considering the skin effect, the effective current-carrying cross-section of multiple conductors is larger than that of a single conductor of the same volume, and a larger current can be transmitted; the first and second conductors of the double-layer feeding device are exposed, and the exposed conductors have fast heat dissipation and large current carrying capacity compared with the sealed coaxial high-voltage cable, and can carry a larger transmission power; and the air medium is mainly between the first feeder ring and the second feeder ring, the distributed capacitance is small, and there is basically no dielectric loss, and the transmission efficiency is higher than that of the general coaxial high-voltage cable. The low-frequency high-power feeding device provided by the present invention includes two impedance transformers, which are respectively arranged at the connection ends of the double-layer feeding cage and the low-frequency high-power transmitter and the tuning device. Through these two impedance converters, the impedance matching between the transmitter and the antenna and the double-layer feeding cage is achieved, the transmission loss of the feeding device is reduced, and the efficient transmission of low-frequency power signals is realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A schematic diagram of the electrical principle of a low-frequency high-power feeding device provided in an embodiment of the present application;

[0023] Figure 2 One of the structural schematic diagrams of a low-frequency high-power feeding device provided in an embodiment of the present application;

[0024] Figure 3 The second structural schematic diagram of a low-frequency high-power feeding device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0026] The terms "first", "second", "third", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0027] Combine the following Figure 1-Figure 3 A low-frequency, high-power feeding device provided by an embodiment of the present invention is described.

[0028] The present invention provides a low-frequency high-power feeding device including a first impedance transformer 20, a double-layer feed cage 30 and a second impedance transformer 40 connected in sequence through a first conductor. The double-layer feed cage includes a frame 31, a first feed line ring 32 and a second feed line ring 33. Among them, an installation space is formed in the frame 31 for arranging the first feed line ring and the second feed line ring 32; the first feed line ring 32 is arranged in the second feed line ring 33, and the outer peripheral wall surface of the second feed line ring 33 is tangent to the inner wall of the frame 31; the first feed line ring 32 and the second feed line ring 33 are fixedly connected to the frame 31 through a mounting frame 34.

[0029] Furthermore, the first feeder ring 32 includes a plurality of first wires 321 arranged along the axial direction, which are connected by a first ring line 322 to form a cylindrical structure; similarly, the second feeder ring 33 also includes a plurality of second wires 331 arranged along the axial direction, which are connected by a second ring line 332 to form a cylindrical structure. This double-layer structure design helps to reduce electromagnetic interference and improve the stability and efficiency of signal transmission.

[0030] Figure 1 The electrical principle diagram of the low-frequency high-power feeding device provided by the present invention is as follows: Figure 1As shown, a low-frequency high-power feeding device of the present invention comprises a first impedance converter, a double-layer feeding cage and a second impedance converter connected in sequence through a first conductor 321. The low-frequency high-power feeding device provided by the present invention is used for transmitting a high-power signal from a low-frequency transmitter, such as a low-frequency high-power transmitter, to a tuning device. The double-layer feeding cage is the main body of the low-frequency high-power signal transmission.

[0031] The first impedance converter is arranged at the connection end between the first conductor 321 of the double-layer feed cage and the low-frequency transmitter, and is used to convert the output impedance of the transmitter to the characteristic impedance of the double-layer feed cage. The transformation ratio of the first impedance converter is a fixed value, 1:n is the impedance transformation ratio, and is used to convert the impedance between the double-layer feed cage and the low-frequency high-power transmitter at a fixed ratio to achieve good impedance matching between the two and ensure the effective transmission of the radio frequency signal therebetween. Due to its fixed transformation ratio, it provides a stable starting condition for the signal transmission of the entire feeding device.

[0032] In the initial stage of low-frequency, high-power signal transmission, the first impedance transformer with a fixed transformation ratio ensures a smooth transition of the signal from the transmitter to the double-layer feed cage, avoiding signal reflection and loss caused by transformation ratio fluctuations, and laying the foundation for subsequent efficient transmission. It should be noted that when designing this system, for the connection combination of the low-frequency, high-power transmitter and the double-layer feed cage under specific operating frequency, power and other conditions, an optimal fixed transformation ratio can be determined through experiments or theoretical calculations. This transformation ratio can be optimized according to different specific application scenarios, so that the transmission loss can be minimized in this scenario.

[0033] The second impedance converter is arranged at the connection end between the first conductor 321 of the double-layer feed cage and the tuning device. Among them, the transformation ratio of the second impedance converter is an adjustable value. By adjusting the transformation ratio, the impedance between the double-layer feed cage and the tuning device can be matched under different working conditions, ensuring the stable transmission of the RF signal in the connection part. The connection between the coaxial feed cable and the tuning device will face a variety of different working conditions. For example, factors such as different transmission distances, ambient interference, and changes in the state of other components in the system may cause the optimal impedance matching state between the two to change. The second impedance converter with an adjustable transformation ratio can be flexibly adjusted according to these changes. For example, when the transmission distance increases, the attenuation characteristics of the signal in the coaxial feed cable will change. At this time, the impedance of the coaxial feed cable and the tuning device can be re-matched by adjusting the transformation ratio of the second impedance converter to compensate for the impact of this attenuation and reduce transmission losses.

[0034] During the operation of the entire feeding device, by adjusting the transformation ratio of the second impedance converter, the signal transmission from the coaxial feed cable to the tuning device can be dynamically optimized. For example, when the system needs to transmit low-frequency, high-power signals of different frequencies, the optimal impedance matching conditions corresponding to different frequencies are different according to the relationship between frequency and impedance. The second impedance converter with adjustable transformation ratio can flexibly adjust the transformation ratio according to the actual transmission frequency, so that better impedance matching can be achieved at various frequencies, reducing signal reflection and loss, thereby realizing efficient transmission of low-frequency, high-power signals at different frequencies.

[0035] In addition, in the actual operation of the feeding device, factors such as the manufacturing tolerance of the components and aging after long-term use will cause the actual impedance characteristics to deviate from the design value. The adjustable ratio function of the second impedance transformer can compensate for these deviations. Assuming that the characteristic impedance of the coaxial feed cable has changed slightly due to long-term use, by adjusting the ratio of the second impedance transformer, the impedance of the tuning device and the changed coaxial feed cable can be re-matched to ensure the efficiency of signal transmission. This flexibility can effectively reduce the increase in transmission loss caused by factors such as system errors and component aging, and extend the effective service life of the entire feeding device.

[0036] In a preferred embodiment, the output impedance of the low-frequency high-power transmitter is, for example, 10Ω, and the characteristic impedance of the double-layer feed cage is, for example, 60Ω, so the impedance transformation ratio is set to 1:6. The second impedance transformer is arranged at the connection end of the double-layer feed cage and the tuning device, and is used to transform the antenna impedance to the characteristic impedance of the double-layer feed cage. Since the antenna impedance varies with the frequency within the working frequency band, and its order of magnitude varies between about 0.3Ω-1.0Ω, the second impedance transformer is set to an adjustable transformation ratio, and the transformation ratio can be between 60-200, which is controlled and adjusted by the tuning device.

[0037] Figure 2 One of the schematic diagrams of the double-layer feeding cage structure of the low-frequency high-power feeding device provided by the present invention is as follows Figure 1 As shown, a double-layer feed cage of a low-frequency high-power feeding device of the present invention includes a frame 31, a first feeder ring 32 and a second feeder ring 33. An installation space is formed in the frame 31 for arranging the first feeder ring 32 and the second feeder ring 33. The first feeder ring 32 is arranged in the second feeder ring 33, and the two can be coaxially arranged. The outer peripheral wall surface of the second feeder ring 33 is tangent to the inner wall of the frame 31 to ensure a close fit between the two.

[0038] The first feeder ring 32 may include a plurality of first wires 321 arranged along the axial direction, and these wires are connected to form a cylindrical structure by a first ring line 322. The second feeder ring 33 may also include a plurality of second wires 331 arranged along the axial direction, and these wires are connected to form a cylindrical structure by a second ring line 332. This double-layer structure design helps to reduce electromagnetic interference and improve the stability and efficiency of signal transmission.

[0039] In a preferred embodiment, Figure 2 As shown, the low-frequency high-power feeding device provided by the present invention can be a coaxial feeding device structure composed of multiple first conductors 321 and multiple second conductors 331, multiple first conductors 321 with a radius of r1 are evenly arranged in a circle to form a first feeder ring 32 with a radius of R1 and a cylindrical shape, wherein the multiple first conductors 321 are connected through a first ring line 322; multiple second conductors 331 with a radius of r2 are evenly arranged in a circle to form a second feeder ring 33 with a radius of R2 and a cylindrical shape, wherein the multiple second conductors 331 are connected through a second ring line 332. It is worth noting that, considering the skin effect, multiple conductors have a larger effective current-carrying cross-section than a single conductor of the same volume, and can transmit a larger current.

[0040] The low-frequency high-power feeding device can be used to transmit the energy output by the transmitter to the tuning device, playing a role in high-power transmission. The requirements for it are no leakage, high transmission efficiency, and the ability to withstand large currents and certain voltages. Among them, the first feeder loop 32 can play a role in high-power transmission, and the second feeder loop 33 can play a shielding role to ensure that the feeder is basically radiation-free.

[0041] Preferably, the mounting frame 34 is an insulating support assembly, and the insulating support assembly can be a capped rod insulator 35. The first feeder ring 32 and the second feeder ring 33 are fixed between two groups of wires by a capped rod insulator 35, and the insulator withstand voltage can be selected as 20kV.

[0042] Preferably, the first conductor 321, the second conductor 331 and the first feeder ring 32 are made of pure copper. The second feeder ring 33 has relatively low conductivity requirements and can be made of angle steel. The first feeder ring 32 and the second feeder ring 33 can usually be provided one every 10 meters.

[0043] Preferably, the number of first wires 321 is determined as follows:

[0044] ;

[0045] in, is the number of first wires 321; is the total current carrying capacity; is the current carrying capacity per unit area; is the radius of the first conductor 321; is the skin depth.

[0046] Preferably, the number of the second wires 331 is determined as follows:

[0047] ;

[0048] ;

[0049] in, is the number of the second wires 331; is the conductor ground current; is the current of the first conductor 321; is the radius of the second feeder loop 33; The equivalent radius of the second feeder loop 33.

[0050] The specific design standards are as follows:

[0051] 1. Design of the first conductor 321

[0052] Double-layer feeders can use pure copper conductors. According to the power system specifications, the conductors must operate within the maximum current carrying capacity to avoid damaging the physical properties of the conductor material. The calculation formula is as follows:

[0053] (1)

[0054] Optional, copper current carrying capacity U is 4.5A / mm 2 , copper current carrying capacity can reach 6 A / mm in open environment 2 .

[0055] The effective current-carrying area S of a single conductor:

[0056] (2)

[0057] in, is the total current carrying capacity; is the current carrying capacity per unit area; is the radius of the first conductor 321; is the skin depth. The low-frequency skin depth of copper conductor is shown in Table 1.

[0058] Table 1. Low frequency skin depth of copper conductor

[0059]

[0060] According to the low-frequency skin depth of the copper wire is about 0.5mm, the first wire is a single wire with a radius of r1=3mm, so the number of wires n1 is required to be:

[0061] (3)

[0062] in, is the number of the first wire 321; Substituting the parameters into formula (3), we can get the number of the first wire 321 :

[0063] In this embodiment, 1000 / [6×3.14×0.5×(2×3-0.5)]=19.3; therefore, the number of the first conductive wires 321 is 20, and therefore, the first conductive wires 321 are 20 φ6 mm pure copper wires.

[0064] 6.2 Design of the Second Wire 331

[0065] The number of shielded wires in the second feeder loop 33 depends on the requirement for the degree of shielding and is determined by the ratio of the feeder ground current Ig to the current I of the first wire 321. When the height of the center of the double-layer feeding device from the ground is H=3m, the radius of the second feeder loop 33 is R2=0.6m, and the wire radius is r2=2mm, the ratio of the feeder ground current to the current of the first wire 321 is:

[0066] (4)

[0067] When the radius of the second wire 331 is r2, the number of the second wires 331 is n2, and the radius of the second feeder loop 33 is R2, the equivalent radius Re2 of the second feeder loop 33 is:

[0068] (5)

[0069] in, is the number of the second wires 331; is the conductor ground current; is the current of the first conductor 321; is the radius of the second feeder loop 33; The equivalent radius of the second feeder loop 33.

[0070] Typically, the allowable value of the ratio of the feeder ground current to the first conductor 321 current is Ig / I=2%.

[0071] In this embodiment, considering that the calculation of formula (4) is complicated, different n2 values ​​are substituted into formula (4). When n2=30, Ig / I≈2%, therefore, the second conductor 331 is 30 φ4 mm pure copper wires.

[0072] 6.3 Design of characteristic impedance of feeding device

[0073] The characteristic impedance value of the double-layer feeding device is generally determined according to the output impedance of the transmitter and the size of the feeding device. When the radius of the first wire 321 is r1, the number of the first wires 321 is n1, and the radius of the first feeder loop 32 is R1, the equivalent radius Re1 of the first feeder loop 32 is:

[0074] (6)

[0075] The characteristic impedance W0 of the double-layer feeding device is:

[0076] (7)

[0077] It should be noted that the characteristic impedance of the low-frequency high-power feeder is generally 50Ω to 70Ω. When the current carrying capacity is constant, the larger the characteristic impedance, the higher the transmission efficiency of the feeder, but the larger the size of the second feeder loop 33. Taking into account the transmission efficiency and the size limit of the feeder, the characteristic impedance of the feeder in this example is selected to be 60Ω.

[0078] 6.4 Feeder losses

[0079] The loss resistance Rl per unit length of the feeding device is:

[0080] (8)

[0081] Where: S1 and S2 are the effective current-carrying areas of the single copper wires of the first feeder loop 32 and the second feeder loop 33, respectively, calculated by equation (2), and σ is the conductivity of the copper wire, which is 5.8×10 7 s / m.

[0082] The attenuation constant α of the feeder is calculated from the loss resistance per unit length Rl and the characteristic impedance of the feeder:

[0083] (9)

[0084] The calculated attenuation constant of the feeder at a typical frequency of 20kHz is 1.77×10 -6 Np / m, converted to decibel, is 0.0154dB / km. It can be seen that the feeding device of this design example has a low attenuation constant and high transmission efficiency, and is suitable for long-distance transmission of low-frequency and high-power signals.

[0085] In a preferred embodiment, the output impedance of a typical all-solid-state high-power low-frequency transmitter is 10Ω, the maximum output current of the transmitter is Imax=1000A, and the output voltage is 1000A×10Ω=10000V. Considering the design margin, the feeder usually needs to withstand 1000A current and 20kV voltage. The low-voltage feeder is an inner and outer double-layer structure, the first feeder ring 32 is concentric with the second feeder ring 33, the second conductor 331 is 30 φ4mm pure copper wires, and the radius of the second feeder ring 33 is R1=0.6m; the first conductor 321 is 20 φ6mm pure copper wires, and the first feeder ring 32 has a radius of R2=0.25m. The first feeder ring 32 and the second feeder ring 33 are separated and fixed on the feeder frame by a plurality of capped rod insulators 35; the low-voltage feeder meets the working requirement of 1000A (effective value) of continuous working current at 15kHz, and the insulators between the second feeder rings 33 meet the working requirement of 20 kV (effective value) of continuous working voltage at 15kHz.

[0086] It is worth noting that due to the large current of the feeder, when it is close to the ground, it will cause a large ground loss. Therefore, the feeder needs to be installed overhead. It can be installed on the top feeder rack of a self-supporting steel pipe pole. The center distance of the feeder is preferably not less than 3 meters from the ground. The installation diagram, for example Figure 3 shown.

[0087] In a preferred embodiment, the top feeder frame can be designed as a hexagon, made of L63×6 angle steel, just surrounding the second feeder ring 33 of the feeder, and the second feeder ring 33 is electrically connected to the top feeder frame as a whole. Three insulators are fixed to the three short sides of the top feeder frame in a Y shape with the center of the feeder as the starting point, and the first feeder ring 32 of the feeder is fixed on three capped rod insulators 35 and insulated from the second feeder ring 33.

[0088] The main parameters of the self-supporting steel pipe pole 36 are: diameter φ133, thickness 6mm, height about 2m; the center of the elevated feeding device is not less than 3 meters from the ground, which can prevent people and animals from touching the feeding device and causing safety accidents.

[0089] The low-frequency high-power feeding device provided by the present invention comprises a coaxial double-layer structure composed of a plurality of first conductors 321 and a plurality of second conductors 331. The first feeder ring 32 and the second feeder ring 33 are both composed of a plurality of conductors. Compared with a general coaxial high-voltage cable, the feeding device composed of the plurality of conductors has low loss and strong wind resistance. Compared with a feeder tube, the feeding device has light weight and suitable price. Considering the skin effect, the effective current-carrying cross-section of the plurality of conductors is larger than that of a single conductor of the same volume, and a larger current can be transmitted. The first conductor 321 and the second conductor 331 of the double-layer feeding device are exposed. Compared with a closed coaxial high-voltage cable, the exposed conductors have fast heat dissipation and large current carrying capacity, and can carry a larger transmission power. Moreover, the air medium is mainly between the first feeder ring 32 and the second feeder ring 33, the distributed capacitance is small, and there is basically no dielectric loss. Compared with a general coaxial high-voltage cable, the transmission efficiency is higher.

[0090] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0091] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0092] The above is only an exemplary embodiment of the present disclosure, and the scope of the present disclosure cannot be limited thereto. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the specification and practicing the disclosure here, those skilled in the art will easily think of the implementation scheme of the present disclosure. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the technical field not recorded in the present disclosure. The description and examples are only regarded as exemplary, and the scope and spirit of the present disclosure are defined by the claims.

[0093] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0094] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A low-frequency high-power feeding device, characterized in that: include: A first impedance transformer, a double-layer feeding cage, and a second impedance transformer connected in sequence through a first conductor; the first impedance transformer is arranged at a connection end between the double-layer feeding cage and the low-frequency transmitter, and the transformation ratio of the first impedance transformer is a fixed value, and is used to impedance match the impedance between the double-layer feeding cage and the low-frequency transmitter at a fixed ratio; The double-layer feed cage includes a frame, an installation space is formed in the frame, and a first feeder ring and a second feeder ring are arranged in the installation space; wherein the first feeder ring is arranged in the second feeder ring, the outer peripheral wall of the second feeder ring is tangent to the inner wall of the frame, and the first feeder ring and the second feeder ring are fixedly connected to the frame through a mounting frame; the first feeder ring includes a plurality of first conductors arranged along the axial direction, and the plurality of first conductors are connected by a first loop wire to form a cylindrical structure; the second feeder ring includes a plurality of second conductors arranged along the axial direction, and the plurality of first conductors are connected by a second loop wire to form a cylindrical structure; The second impedance transformer is arranged at the connection end between the double-layer feeding cage and the tuning device; the transformation ratio of the second impedance transformer is a non-fixed value, so as to adjust the transformation ratio so that the impedance between the double-layer feeding cage and the tuning device can be matched under different working conditions.

2. The low-frequency high-power feeding device according to claim 1, characterized in that: The first feeder loop and the second feeder loop are coaxially arranged.

3. The low-frequency high-power feeding device according to claim 1, characterized in that: The number of the first conductors is determined as follows: ； in, is the number of first wires; is the total current carrying capacity; is the current carrying capacity per unit area; is the radius of the first conductor; is the skin depth.

4. The low-frequency high-power feeding device according to claim 3, characterized in that: The number of the second conductors is determined as follows: ； ； in, is the number of the second conductor; is the conductor ground current; is the first conductor current; is the radius of the second feeder loop; Equivalent radius of the second feeder loop.

5. The low-frequency high-power feeding device according to claim 1, characterized in that: The mounting frame is an insulating support assembly, and the insulating support assembly includes a plurality of capped rod-shaped insulators.

6. The low-frequency high-power feeding device according to claim 1, characterized in that: The first conductive line, the second conductive line and the first loop wire are made of copper.

7. The low-frequency high-power feeding device according to claim 1, characterized in that: The material of the second loop wire includes copper or steel.

8. The low-frequency high-power feeding device according to claim 1, characterized in that: The frame body also includes radially connected support rods for overhead power feeding.

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