A series resonance experimental device

Abstract

The application relates to a series resonance experiment device and relates to the technical field of electric load detection instruments.The device comprises a variable-frequency power supply, an excitation transformer, a reactor and a voltage divider.The variable-frequency power supply is connected with the reactor through the excitation transformer.The reactor is connected in series with a product to be tested, and the voltage divider is arranged between the reactor and the product to be tested for test control.The reactor comprises a vertically arranged shell, an axially arranged coil winding, an axially movable magnetic core assembly and a driving mechanism.The magnetic core assembly is composed of multiple detachable sub-magnetic cores.The driving mechanism is used for adjusting the axial position of the magnetic core assembly, so that part of the sub-magnetic cores enter the inside of the coil winding, and the equivalent inductance of the coil is adjusted.The structure is beneficial to continuously adjusting the inductance value, adapting to the experimental requirements under different resonance conditions, and improving the debugging efficiency and the parameter control accuracy.

Description

Technical Field

[0001] This application relates to the field of power load detection instruments, and in particular to a series resonance experimental device. Background Technology

[0002] Currently, series resonant test devices are widely used as important tools for testing the dielectric strength of electrical equipment, and are applied to verify the insulation performance of cables, capacitors, transformers, and other equipment. Their basic working principle is to adjust the excitation source frequency to create a series resonance between the capacitance of the test object and the inductance of the reactor, thereby generating a resonant voltage of sufficient amplitude on the test object. However, due to the varying capacitances of different test objects and the limited frequency adjustment range or accuracy of some variable frequency power supplies, frequency adjustment alone is often insufficient to cover all test requirements. Therefore, in engineering practice, auxiliary adjustment of the inductance is often necessary to achieve accurate resonance. Existing adjustment methods mostly rely on replacing the reactor or roughly adjusting the inductance through mechanical series-parallel combinations, which is not only cumbersome and has low adjustment accuracy, but also difficult to achieve rapid switching or dynamic adjustment, showing significant shortcomings, especially in scenarios involving multiple tests or varying loads. Summary of the Invention

[0003] This application provides a series resonance experimental device to at least partially solve the above-mentioned technical problems.

[0004] To achieve the above objectives, this application provides a series resonance experimental device, including a frequency converter, an excitation transformer, a reactor, and a voltage divider. The output terminal of the frequency converter is electrically connected to the input terminal of the excitation transformer, and the output terminal of the excitation transformer is electrically connected to the input terminal of the reactor. The reactor is configured to be connected to the product under test, and the voltage divider is connected in series between the reactor and the product under test.

[0005] The reactor includes a housing, a coil winding, a core assembly, and a drive mechanism. The housing is configured to be placed vertically on the ground. The coil winding is axially mounted inside the housing. The core assembly is axially movably connected to the housing and includes a plurality of axially detachably connected sub-cores. The drive mechanism is mounted on the housing and configured to drive the core assembly to move axially to drive at least one of the sub-cores to be located within the coil winding.

[0006] Optionally, the drive mechanism includes a guide assembly and a drive assembly. The guide assembly is axially connected to the housing and passes axially through the inner ring of the coil winding. The plurality of sub-magnetic cores are movably connected to the guide assembly along the extension direction of the guide assembly. The drive assembly is configured to be drively connected to the guide assembly to drive the plurality of sub-magnetic cores to move axially.

[0007] Optionally, the guide assembly includes an insulating threaded rod and an insulating guide rod. The insulating threaded rod and the insulating guide rod are coaxially connected inside the housing and axially pass through the inner ring of the coil winding. The sub-core is axially provided with a threaded hole and a guide hole. Each sub-core is threadedly engaged with the insulating threaded rod through the threaded hole, and each sub-core is slidably engaged with the insulating guide rod through the guide hole.

[0008] The insulating threaded rod is rotatably connected to the housing, and the drive assembly is used to drive the insulating threaded rod to rotate.

[0009] Optionally, the drive assembly includes a drive rod, a rotating handle, and a driving bevel gear. The drive rod is rotatably connected to the side wall of the housing near the ground. The rotating handle is connected to the end of the drive rod located outside the housing. The driving bevel gear is coaxially connected to the end of the drive rod located inside the housing. A driven bevel gear is coaxially connected to the rod wall near the bottom of the insulated threaded rod. The driven bevel gear meshes with the driving bevel gear.

[0010] Optionally, each of the two axial ends of the sub-core is provided with an insulating connecting ring, the insulating connecting rings on two adjacent sub-cores are in contact with each other, the outer diameter of the insulating connecting ring is larger than the outer diameter of the sub-core, a connecting screw hole is provided through the insulating connecting ring, the connecting screw holes on two adjacent insulating connecting rings are axially aligned, and a countersunk groove is provided at the opposite ends of two adjacent connecting screw holes, a connecting bolt is threaded through the internal threads of two adjacent connecting screw holes, and the nut of the connecting bolt is located in the countersunk groove.

[0011] Optionally, a bottom support frame is provided on the inner bottom wall of the housing, the rotation of the insulating threaded rod passes through the bottom support frame, the lower end of the insulating guide rod is fixedly connected to the bottom support frame, and the upper surface of the bottom support frame is flush with the lower end face of the coil winding.

[0012] When the driving assembly drives the insulating connecting ring located at the lowest end of the plurality of sub-cores to fit against the lower surface of the bottom support frame, the upper surface of the insulating connecting ring located at the highest end of the plurality of sub-cores is flush with the upper end surface of the coil winding.

[0013] When the driving assembly drives the uppermost insulating connecting ring of the multiple sub-cores to fit against the inner top wall of the housing, the lowermost sub-core is located inside the coil winding, and the upper surface of the insulating connecting ring at the upper end of the corresponding sub-core is flush with the upper end surface of the coil winding.

[0014] Optionally, it also includes a depth marking mechanism, wherein multiple depth marking mechanisms are provided on the housing, and each depth marking mechanism is connected to a sub-magnetic core for marking the depth of the magnetic core assembly entering the coil winding.

[0015] Optionally, the depth marking mechanism includes a marking connection component and a visual tube. The visual tube is coaxially mounted on the outer wall of the housing. One end of the marking connection component is slidably connected to the inside of the visual tube, and the other end is connected to the insulating connection ring of the sub-magnetic core. The visual tube has scale markings along its own length direction. The scale marking value corresponding to the position of the marking connection component inside the visual tube is configured to indicate the depth of the magnetic core assembly entering the coil winding.

[0016] Optionally, the marking connection assembly includes a connecting rope and a marking slider. A sliding channel is provided within the top wall of the housing. The sliding channel includes a horizontal slide rail and a vertical slide rail that are connected. The end of the horizontal slide rail away from the vertical slide rail is located above the top of the visual tube. The end of the vertical slide rail away from the horizontal slide rail is axially connected to the housing. The marking slider is slidably disposed within the visual tube. One end of the connecting rope passes sequentially through the vertical slide rail, the horizontal slide rail, and the top wall of the visual tube before connecting to the marking slider; the other end extends axially along the housing and connects to an insulating connecting ring.

[0017] When the driving assembly drives the insulating connecting ring located at the lowest end of the plurality of sub-magnetic cores to abut the lower surface of the bottom support frame, the marking slider abuts the inner top wall of the visual tube;

[0018] When the driving assembly drives the uppermost insulating connecting ring of the plurality of sub-magnetic cores to adhere to the inner top wall of the housing, the marking slider adheres to the inner bottom wall of the visual tube.

[0019] Optionally, the connection between the horizontal slide and the vertical slide is a smooth transition with rounded corners, and a steering wheel is rotatably provided on the housing between the port of the horizontal slide and the top wall of the visible tube. The steering wheel is configured to slide and fit against the connecting rope.

[0020] In summary, this application includes at least one of the following beneficial technical effects:

[0021] 1. This invention, by setting up a core assembly composed of multiple sub-cores that is adjustable as a whole, and combining it with a guide assembly consisting of an insulated threaded rod and an insulated guide rod, and an engaging drive assembly, enables multiple sub-cores to achieve synchronous, controllable, and step-by-step axial movement while ensuring coaxial positioning. The threaded rod drives the sub-cores to rise or fall along the guide direction, and combined with the circumferential limiting function provided by the guide rod, each sub-core maintains an accurate linear displacement direction during movement, thereby avoiding problems such as tilting, jamming, or uneven movement of the core assembly, and improving the reliability and consistency of the adjustment operation. This structure is particularly suitable for series resonant experiments requiring frequent adjustments to inductance or magnetic flux, and to a certain extent, it is beneficial for achieving precise control of the magnetic flux path, helping the adjusted coil system maintain stable inductance parameters and efficient magnetic field coupling, thereby improving the experimental repeatability and control accuracy of the entire resonant system.

[0022] 2. The depth marking mechanism of this invention, combined with the linkage structure of the visual tube, marking slider, and connecting rope, enables synchronous association between the magnetic core assembly and the external position indicator during movement, thus intuitively indicating the actual depth of the magnetic core assembly entering the coil winding. By setting a sliding channel inside the housing, the connecting rope connected to the magnetic core assembly is guided to the position of the visual tube. Combined with the sliding positioning of the marking slider inside the visual tube, the operator can know the relative position and moving distance of the magnetic core assembly from outside the equipment. Simultaneously, the scale markings on the visual tube provide quantifiable depth information, improving the readability of parameter control and the convenience of operation. Furthermore, by setting connecting ropes of varying lengths on multiple sub-cores, the marking sliders in multiple visual tubes can remain in the same position under normal operating conditions, thus possessing self-checking capabilities. This facilitates the determination of whether the magnetic core assembly is misaligned, faulty, or loose, providing a certain early warning function. While ensuring experimental safety, it also improves the stability of system operation and the operability of maintenance.

[0023] 3. By setting multiple horizontally spaced insertion holes on each visible tube, and in conjunction with an insertable baffle structure, a multi-level limiting function for the movement position of the indicator slider is achieved. This structure allows the displacement distance of the magnetic core assembly to be precisely limited to an integer multiple of the total height of a single sub-core (including the thickness of the upper and lower insulating connecting rings) with each adjustment, ensuring that each movement ensures that a sub-core completely enters or exits the coil winding. This structural design avoids the magnetic flux leakage problem caused by the sub-core part being suspended outside the coil winding boundary, which is beneficial to maintaining the integrity of the system's magnetic field distribution and the linear response of inductor adjustment. In addition, this baffle limiting design is simple in structure and easy to operate. Users can quickly insert and remove the corresponding baffles according to experimental needs, thereby facilitating rapid adjustment and repeated precise positioning of the magnetic core assembly, which helps to improve experimental efficiency and the consistency of parameter control. It is suitable for various high-frequency precision requirements such as teaching, scientific research, and debugging. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0026] Figure 1 This is a schematic diagram of the arrangement structure of the series resonance experimental device provided in the embodiments of this application;

[0027] Figure 2 This is an internal cross-sectional view of the reactor provided in the embodiments of this application;

[0028] Figure 3 This is a partial cross-sectional view of the reactor provided in the embodiment of this application;

[0029] Figure 4 yes Figure 3 An enlarged schematic diagram of part A in the middle;

[0030] Figure 5 This is a schematic diagram showing the state in which the magnetic core assembly of the reactor provided in this application is completely inserted into the coil winding.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1. Variable frequency power supply;

[0033] 2. Excitation transformer;

[0034] 3. Voltage divider;

[0035] 4. Reactor;

[0036] 5. Housing; 51. Bottom support frame; 511. Limiting plate; 52. Sliding channel; 521. Horizontal slide rail; 522. Vertical slide rail; 53. Steering wheel;

[0037] 6. Coil winding;

[0038] 7. Magnetic core assembly; 71. Sub-core; 711. Threaded hole; 712. Guide hole; 713. Insulating connecting ring; 714. Connecting screw hole; 715. Countersunk groove; 716. Connecting bolt;

[0039] 8. Drive mechanism; 81. Guide assembly; 811. Insulated threaded rod; 812. Insulated guide rod; 82. Drive assembly; 821. Drive rod; 822. Rotating handle; 823. Drive bevel gear;

[0040] 9. Depth marking mechanism; 91. Marking connection assembly; 911. Connecting rope; 912. Marking slider; 92. Visible tube; 921. Insertion hole;

[0041] 10. Baffle plate. Detailed Implementation

[0042] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0043] This application provides a series resonance experimental setup. Please refer to [link / reference]. Figure 1 and Figure 2 The series resonant experimental setup includes a frequency converter 1, an excitation transformer 2, a reactor 4, and a voltage divider 3. The output terminal of the frequency converter 1 is electrically connected to the input terminal of the excitation transformer 2, and the output terminal of the excitation transformer 2 is electrically connected to the input terminal of the reactor 4. The reactor 4 is configured to be connected to the product under test. The voltage divider 3 is connected in series between the reactor 4 and the product under test to monitor the voltage on the product under test.

[0044] For example, the reactor 4 includes a housing 5, a coil winding 6, a magnetic core assembly 7, and a drive mechanism 8. The housing 5 is configured to be placed vertically on the ground so that the internal magnetic flux path is aligned with the direction of gravity, which facilitates the vertical guidance of the magnetic core assembly 7 and the control of the mechanical center of gravity. The coil winding 6 is axially mounted inside the housing 5 and connected to the external terminals to form an electrical path.

[0045] For example, the magnetic core assembly 7 includes a plurality of axially detachably connected sub-cores 71, which are detachably connected and together constitute a magnetic core assembly 7 that can be inserted or withdrawn in the vertical direction. The magnetic core assembly 7 is arranged coaxially with the central channel of the coil winding 6.

[0046] For example, the drive mechanism 8 is mounted on the upper part of the housing 5 and is used to drive the magnetic core assembly 7 to move up and down axially under the drive of manual or electronic signals. It is understood that the drive mechanism 8 may include a rotating handwheel and lead screw mechanism, or a rack and pinion structure driven by a servo motor, and is connected to the magnetic core assembly 7 through a transmission rod.

[0047] Based on this, within the axial height range of the coil winding 6, the core assembly 7 can achieve continuous movement from a mostly withdrawn state to a fully inserted state, and within the movement range, the number of sub-cores 71 inserted can be controlled in stages. In actual operation, when the resonance requirement of the product under test is high, multiple sub-cores 71 can be inserted into the coil winding 6 through the drive mechanism 8. The increased insertion length increases the effective core length in the coil, increases the magnetic flux, and increases the inductance value of the reactor 4, which is beneficial to shifting the resonance point to the target frequency range. When the resonance requirement of the product under test is not high, or when frequency matching needs to be adjusted, the drive mechanism 8 can drive the core assembly 7 to remove some sub-cores 71 from the coil winding 6, leaving only one sub-core 71 inside the coil winding 6, thereby reducing the inductance to a certain extent and meeting the needs of frequency adjustment. In this structure, the arrangement of multiple sub-cores 71 provides the core assembly 7 with segmented adjustment freedom, avoiding resonance deviation caused by excessive adjustment at one time. At the same time, the inductance value can be continuously or stepwise adjusted through the mechanical structure to adapt to various loads and test requirements. It has a certain degree of operational flexibility and adjustment stability when frequently switching between different test samples or when there are multiple sets of test conditions.

[0048] Furthermore, the length of each sub-core 71 in the core assembly 7 is less than the axial length of the coil winding 6, and the maximum insertion depth of the core assembly 7 does not exceed the axial length of the coil winding 6, to avoid magnetic field distortion caused by some sub-cores 71 being located in non-coil areas. In terms of structural design, inductance adjustment is achieved through the insertion and removal of the core assembly 7. Compared with the traditional method of relying on replacing the reactor 4 or through electronic frequency modulation, this reduces operational complexity to a certain extent, while taking into account safety and structural controllability. This allows the device to exhibit good precision adjustment capability and adaptability during inductance adjustment under series resonance conditions.

[0049] In some embodiments, such as Figure 2 , Figure 3 and Figure 4As shown, the drive mechanism 8 includes a guide assembly 81 and a drive assembly 82. The guide assembly 81 is axially connected inside the housing 5 and passes through the central hole of the coil winding 6. It mainly consists of an insulated threaded rod 811 and an insulated guide rod 812 coaxially arranged with it. These two are parallel to each other in the vertical direction, serving the functions of axial propulsion and radial limiting, respectively. Each sub-core 71 has a through threaded hole 711 and a guide hole 712. The threaded hole 711 and the insulated threaded rod 811 have a threaded fit, while the guide hole 712 and the insulated guide rod 812 have a sliding fit. When the insulated threaded rod 811 rotates under the drive assembly 82, the multiple sub-cores 71 cannot rotate due to the limiting effect of the guide rod, and therefore move along the axial direction of the insulated threaded rod 811.

[0050] For example, multiple sub-cores 71 are combined into an integral core assembly 7 by means of plug-in, positioning pin, or threaded connection, so that they can be driven as an integral structure during the driving process. Further, the driving assembly 82 includes a rotating handle 822, a driving rod 821, and a driving bevel gear 823. The driving rod 821 is rotatably connected to the side wall of the housing 5 near the ground through a mechanism such as bearings. The rotating handle 822 is located at the end of the driving rod 821 located on the outside of the housing 5 for easy manual operation. The other end of the driving rod 821 is coaxially connected to a driving bevel gear 823. A driven bevel gear is coaxially connected to the rod wall near the bottom of the threaded rod. The driving bevel gear 823 meshes with the driven bevel gear.

[0051] It is understandable that when the operator rotates the handle 822, the driving bevel gear 823 drives the driven bevel gear to rotate, which in turn drives the insulated threaded rod 811 to rotate. Through this rotational action, the sub-core 71 will generate an axial displacement of rising or falling in the vertical direction, realizing the synchronous adjustment of the insertion depth of the sub-core 71 into the coil winding 6. When multiple sub-cores 71 gradually enter the area of ​​the coil winding 6, their coverage of the axial length of the coil increases, which is beneficial to increasing the inductance value and adjusting the resonant frequency; when multiple sub-cores 71 gradually withdraw from the area of ​​the coil winding 6, leaving only a few or a single sub-core 71 inside the coil, the proportion of cores in the coil decreases, the inductance value decreases to a certain extent, and the frequency increases accordingly.

[0052] Based on this, the structure possesses excellent flexibility in inductance adjustment, making it particularly suitable for testing needs involving frequent changes in test product types or a wide range of resonant frequencies. Furthermore, both the insulating threaded rod 811 and the insulating guide rod 812 are made of non-magnetic, high-voltage resistant insulating materials to reduce electric field interference and improve structural safety and electromagnetic field uniformity. A suitable gap is reserved between the center aperture of the coil winding 6 and the maximum outer diameter of the magnetic core assembly 7 to reduce mechanical interference during insertion and removal, while ensuring that the magnetic flux is concentrated to a certain extent through the interior of the magnetic core, thus maintaining a predictable response curve during inductance adjustment. The structure described in this embodiment completes the adjustment process through a purely mechanical structure, eliminating the need to replace the reactor 4 or connect to an external electronic control circuit. It boasts advantages such as compact structure, high maintainability, and high adjustment accuracy, making it suitable for long-term repeated use under various scenarios and load conditions.

[0053] In some implementations, such as Figure 2 , Figure 3 and Figure 4As shown, to ensure stable assembly of the sub-cores 71 and reduce interference with the magnetic flux path while maintaining structural strength, each sub-core 71 is provided with insulating connecting rings 713 at both axial ends. The insulating connecting rings 713 are made of non-metallic material, possessing good insulation and mechanical strength. Their outer diameter is slightly larger than the outer diameter of the sub-core 71 itself, thus forming an effective end protection structure between the sub-cores 71. Two adjacent sub-cores 71 are respectively butted together by their oppositely positioned insulating connecting rings 713. The connecting rings have a surface-fit structure, and the connection stability is controlled by the flatness of the end faces. Each pair of adjacent insulating connecting rings 713 has a through-hole 714 facing each other along the axial direction, and a countersunk groove 715 is provided at the opposite end of each connecting screw hole 714 to accommodate the nut portion of the connecting bolt 716. During assembly, the connecting bolts 716 are sequentially inserted into two opposing connecting screw holes 714, and the two insulating connecting rings 713 are reliably secured by tightening the threads, forming a structural continuity between the two adjacent sub-cores 71. The nut is completely located inside the recess 715, flush with or slightly below the outer surface of the connecting ring, ensuring a smooth axial structure for the entire connecting assembly. It does not protrude from the outer periphery of the sub-core assembly 7, thus mitigating the influence of metal structural components on the magnetic flux distribution between the coil winding 6 and the core. Simultaneously, the insulating connecting rings 713, forming a non-magnetic spacer layer between the two sub-cores 71, reduce the risk of mechanical vibration coupling between them. During high-frequency or long-term energized testing, this helps reduce the probability of metallic impact sounds or structural resonance, improving the operational stability of the core assembly 7 in the resonant system. Furthermore, the insulating connecting ring 713 has a positioning function in its structure. Through a small flange structure, it works in conjunction with positioning holes or slots on the end face of the sub-core 71 to guide the sub-core 71 to coaxial positioning during assembly, improving linear consistency during axial movement and enhancing the overall structural integrity of the multiple sub-cores 71 during movement. Through this structural design, the core assembly 7, while possessing structural stability and inductance adjustment capabilities, also balances assembly convenience, magnetic flux continuity, and mechanical anti-interference capabilities to a certain extent, making it suitable for resonance testing requirements under various complex operating conditions such as high voltage and high frequency.

[0054] In some examples, such as Figure 2 , Figure 3 and Figure 5As shown, a bottom support frame 51 is provided on the inner bottom wall of the housing 5 to support the magnetic core assembly 7 and limit its range of movement. This bottom support frame 51 is mounted on the inner bottom wall of the housing 5 and has a limiting plate 511. The upper surface of the limiting plate 511 of the bottom support frame 51 is flush with the lower end face of the coil winding 6 in the axial direction, thereby establishing the movable range of the magnetic core assembly 7 on a structural reference. The lower end of the insulating threaded rod 811 rotates through and relative to the bottom support frame 51, allowing the threaded rod to rotate flexibly under the action of the drive assembly 82, driving multiple sub-cores 71 to move as a whole in the axial direction. The lower end of the insulating guide rod 812 is fixedly connected to the bottom support frame 51, serving as a structural reference for the guide trajectory of the magnetic core assembly 7, and its axial rigidity provides a good limiting effect.

[0055] It is understandable that when the drive assembly 82 drives multiple sub-cores 71 to descend until the insulating connecting ring 713 of the lowest sub-core 71 is in contact with the lower surface of the bottom support frame 51 (i.e., the upper surface of the limiting plate 511), the axial length of the entire core assembly 7 is exactly within the range of the coil winding 6. The upper surface of the uppermost insulating connecting ring 713 of the multiple sub-cores 71 is on the same plane as the upper end surface of the coil winding 6, and no sub-core 71 exceeds the upper or lower boundary of the coil winding 6. This structural relationship indicates that the axial arrangement length of the coil winding 6 and the full-load insertion length of the core assembly 7 are equally matched, which can, to a certain extent, ensure that when the core assembly 7 completely moves into the area of ​​the coil winding 6, the upper and lower edges of the core do not cross the boundary. This is beneficial for controlling the magnetic flux to form a relatively closed loop inside the reactor 4, reducing magnetic leakage paths, and improving the magnetic flux utilization efficiency in the inductance adjustment section.

[0056] Meanwhile, when the drive assembly 82 moves multiple sub-cores 71 upwards until the insulating connecting ring 713 of the uppermost sub-core 71 is in contact with the inner top wall of the housing 5, in this position, the lowermost sub-core 71 remains within the coil winding 6, and the upper surface of the insulating connecting ring 713 of this sub-core 71 is flush with the upper end face of the coil winding 6 in the axial direction. This means that even if the entire core assembly 7 is raised to its limit position, the lowermost sub-core 71 remains completely inside the coil winding 6, thus preserving a minimum amount of magnetic flux coupling. This structural constraint ensures that, regardless of whether the core assembly 7 is at its upper or lower limit position during movement, no part of the sub-core 71 will completely detach from the coil winding 6, thereby avoiding the technical risks of magnetic field path breakage, magnetic flux leakage, or a sharp nonlinear decrease in inductance at the limit position.

[0057] It is worth noting that the bottom support frame 51 not only serves as a support and positioning element for the magnetic core assembly 7, but also plays a role in limiting the vertical direction of the magnetic core assembly 7 in the structure. Through its contact relationship with the lowest terminal magnetic core 71, it limits the possibility of the magnetic core assembly 7 continuing to descend. Especially under the influence of external working conditions such as vibration and inertial sinking, it can prevent the magnetic core assembly 7 from undergoing structural displacement to a certain extent, thereby improving the operational stability and reliability of the inductance regulation system in dynamic loading scenarios. In addition, the surface of the limiting plate 511 of the bottom support frame 51 can be covered with an insulating material structure, which has strong anti-interference ability in the electromagnetic environment. It can partially isolate the high magnetic flux density area generated by the magnetic core assembly 7, further compress the magnetic flux leakage path, and is beneficial to improving the overall magnetic field coupling efficiency of the reactor 4.

[0058] Based on this, the bottom support frame 51 clearly defines the maximum insertion depth and minimum retention depth of the magnetic core assembly 7, and constructs a complete insertion-exit stroke reference line based on the flush relationship between the upper and lower boundaries. This ensures that the adjustment stroke is controllable and physically limited, providing basic control precision support for the subsequent linear response matching of inductance and resonant frequency. Furthermore, the two extreme position states defined by the structure also provide a basis for setting the mechanical endpoint position of the drive assembly 82. During adjustment, this reduces structural problems such as jamming and misalignment of the magnetic core assembly 7 caused by misoperation, providing structural assurance for the stable operation of the magnetic field system during the series resonance experiment.

[0059] In some cases, combined Figure 2 , Figure 3 and Figure 5 In accordance with the actual layout requirements of the overall structure, a depth marking mechanism 9 is set on the outside of the housing 5. This aims to intuitively grasp the position of the magnetic core assembly 7 relative to the coil winding 6 from the outside of the housing 5, thereby assisting in judging the current inductance of the reactor 4 and improving debugging efficiency. Specifically, the depth marking mechanism 9 includes a marking connection component 91 and a viewing tube 92. Multiple marking connection components 91 and viewing tubes 92 are provided, that is, the number of each is the same as the number of sub-magnetic cores 71. The viewing tubes 92 are coaxially mounted on the outer wall of the housing 5 in a vertical direction, located outside the housing 5. Each viewing tube 92 is correspondingly set with an insulating connecting ring 713 of a sub-magnetic core 71, and the installation position corresponds one-to-one with the axial arrangement of the magnetic core assembly 7 inside the housing 5.

[0060] Exemplarily, each identification connection component 91 includes a connecting rope 911 and an identification slider 912. The identification slider 912 is slidably disposed inside the visual tube 92 to reflect the axial displacement of the magnetic core assembly 7. One end of the connecting rope 911 passes through the top wall of the housing 5 and is fixedly connected to the insulating connecting ring 713, while the other end is connected to the identification slider 912. Specifically, a sliding channel 52 is provided in the top wall of the housing 5. The connecting rope 911 is guided along the sliding channel 52. The sliding channel 52 includes a vertical slide 522 and a horizontal slide 521. The vertical slide 522 extends axially from the interior of the housing 5 to the top wall. The horizontal slide 521 communicates with the vertical slide 522, and the end of the horizontal slide 521 away from the vertical slide 522 extends to the upper end of the visual tube 92. The connecting rope 911 passes through the sliding channel 52 from inside the housing 5, passes through the top of the visual tube 92, enters the interior of the visual tube 92, and connects to the identification slider 912.

[0061] It is understandable that, since the visible tube 92 is made of transparent material, it has a scale-like marking along its length. The unit of the scale value can be millimeters, centimeters, or other length units, used to characterize the position of the magnetic core assembly 7 relative to the coil winding 6. The position of the marking slider 912 within the visible tube 92 corresponds to the movement depth of the magnetic core assembly 7, thereby reflecting the current proportion of the magnetic core within the coil winding 6 and assisting in the evaluation of inductance changes.

[0062] It is worth noting that the inner diameters of the vertical slide rail 522 and the horizontal slide rail 521 are matched with the outer diameter of the connecting rope 911, thereby preventing the connecting rope 911 from bulging or sinking inside the vertical slide rail 522 or the horizontal slide rail 521. At the same time, a connecting ring is provided on the outer wall of the insulating connecting ring 713, and one end of the connecting rope 911 is tied to the connecting ring. Meanwhile, the connecting ring will not contact the coil winding 6 when moving axially, and the two are in a separated state.

[0063] Based on this, in the process of use, combined with Figure 2 , Figure 5 When the drive assembly 82 drives the magnetic core assembly 7 downward to its deepest state, that is, when the insulating connecting ring 713 at the lowest end of the multiple sub-cores 71 is attached to the lower surface of the bottom support frame 51, the corresponding marking slider 912 is at the highest position inside the viewing tube 92. At this time, the scale marking aligned horizontally with the marking slider 912 indicates that the magnetic core assembly 7 has entered the coil winding 6 to the maximum extent, and the inductance value is at its maximum possible level. At this time, as the entire magnetic core assembly 7 moves vertically downward, it drives the connecting rope 911 to move upward, thereby causing the marking slider 912 connected to it to move towards the top of the viewing tube 92, thus presenting an upward state.

[0064] In another state, combination Figure 2 , Figure 5When the magnetic core assembly 7 is driven upward to its limit position, the uppermost insulating connecting ring 713 of the multiple sub-cores 71 is attached to the inner top wall of the housing 5, and the corresponding marking slider 912 is attached to the inner bottom wall of the viewing tube 92 under the action of gravity. At this time, the scale mark aligned with the upper surface of the marking slider 912 is 0. Although the mark value is 0 from the scale perspective, because the length setting of the sub-cores 71 is matched with the axial height of the coil winding 6, even when the magnetic core assembly 7 reaches the maximum lifting state, the lowermost sub-core 71 is still inside the coil winding 6, and the upper surface of the insulating connecting ring 713 at the upper end of the lowermost sub-core 71 is at the same height as the upper end face of the coil winding 6. This can maintain a minimum inductance output to a certain extent, and the display of the marking slider 912 will not mislead the operator to judge whether the magnetic core has completely exited the coil winding 6.

[0065] Furthermore, the marker connecting component 91 employs a flexible connecting rope 911, allowing it to slide and move with the rise and fall of the magnetic core assembly 7. Simultaneously, a sliding channel 52 located inside the top wall of the housing 5 guides the connecting rope 911, thus limiting its movement path, reducing the possibility of structural interference, and also contributing to the smoothness of the marker slider 912's movement. As a visual displacement element, the marker slider 912's dimensions must be compatible with the inner diameter of the visual tube 92, with a suitable sliding clearance to maintain sliding flexibility while avoiding jamming or shaking that could affect reading accuracy. In addition, since the magnetic core assembly 7 adopts a multi-segment structure, each sub-core 71 is connected and arranged sequentially via insulating connecting rings 713. Each insulating connecting ring 713 can connect to a marker connecting component 91, thus creating a set of equidistant indicating channels on the outer wall of the housing 5 for multiple visual tubes 92. During observation, the depth position of a specific sub-core 71 can be directly read, facilitating the assessment of the current state of the magnetic core assembly 7 within the coil winding 6 and its impact on the magnetic flux.

[0066] It is worth noting that multiple sub-magnetic cores 71 are sequentially combined through insulating connecting rings 713 to form a magnetic core assembly 7. While the heights of each sub-magnetic core 71 differ, the lengths of each visible tube 92 are the same, thus affecting the axial connection length of the connecting rope 911. To ensure that the marker slider 912 within each visible tube 92 remains in a uniform position during normal operation, the length of the connecting rope 911 for each marker connecting assembly 91 is structurally differentiated. This results in a positive correlation between the length of each connecting rope 911 and the axial position and height of its corresponding sub-magnetic core 71. Specifically, the higher the position of the sub-magnetic core 71, the shorter the length of its corresponding connecting rope 911; conversely, the lower the position of the sub-magnetic core 71, the longer the connecting rope 911. Furthermore, the positions of the connecting ropes 911 corresponding to each sub-magnetic core 71 are staggered, preventing them from interfering with each other.

[0067] With this structural design, when the magnetic core assembly 7 moves as a whole under the action of the drive assembly 82, each sub-magnetic core 71 drives its respective connecting rope 911 to slide upwards or downwards, thereby driving the marker slider 912 to slide synchronously within the visual tube 92. Because the length of each connecting rope 911 is precisely adjusted, multiple marker sliders 912 can achieve a uniform sliding distance under the same input action, thus ensuring that the position of the marker slider 912 in each visual tube 92 remains consistent. This facilitates quick judgment of the movement depth and adjustment status of the magnetic core assembly 7 through external observation.

[0068] Furthermore, this structure also assists in anomaly identification. When the position of one or more of the multiple marker sliders 912 deviates from the other marker sliders 912, it usually indicates a change in the length of the connecting rope 911 or an abnormal movement trajectory. For example, a sub-magnetic core 71 may fail to move in sync with the other sub-magnetic cores 71 along the set path, possibly due to a loose internal connection structure of the magnetic core assembly 7 or a misalignment of the sub-magnetic core 71. This structure provides the operator with external observation data for real-time position comparison. Once a difference in the position of the marker sliders 912 is observed, it can be preliminarily determined that there is an operational abnormality in the magnetic core assembly 7, thus providing a basis for timely replacement, adjustment, or reassembly, reducing the possibility of misoperation, and to a certain extent, contributing to improving the stability of system operation and the safety and reliability of equipment operation.

[0069] It is worth noting that the design of the difference in length of the connecting rope 911 does not rely on any active sensors, but rather on a passive feedback mechanism formed by the structural configuration. Therefore, while avoiding the introduction of a complex control system, it increases the observability and ease of maintenance of the structure. Simultaneously, each marking connection component 91 includes a marking slider 912 slidably connected inside the visual tube 92. Guided by the scale markings on the visual tube 92, the marking slider 912 can intuitively display the depth of the magnetic core assembly 7 entering the coil winding 6. Combined with the precise setting of the length of the connecting rope 911, the entire indicating system has good linear response and consistent indicating effect, making it highly practical in experimental tuning or maintenance diagnostic phases.

[0070] This design provides auxiliary judgment criteria for visual monitoring, allowing technicians to adjust the inductor without relying entirely on repeated calculations and experiments. This improves the efficiency and intuitiveness of resonance adjustment and facilitates rapid response to experimental needs under different loads and test conditions. Furthermore, this marking structure does not affect the magnetic coupling between the magnetic core and the coil winding 6, nor does it introduce magnetic flux interference, thus maintaining the operational stability of the reactor 4. Provided the marking slider 912 and the scale are clearly aligned and the connection structure is stable, observing the marking position in the visual tube 92 can, to some extent, help determine the changing trend of the current inductor output level, providing accurate and reliable visual evidence for resonance testing.

[0071] In some implementations, combined with Figure 2 , Figure 3 To further improve the position control accuracy and operational controllability of the magnetic core assembly 7 during movement, at least one insertion hole 921 is provided laterally along the length direction on the wall of each viewing tube 92. The insertion hole 921 is used to insert the baffle 10. For example, if there are three sub-magnetic cores 71, then there is one insertion hole 921 located in the middle of the viewing tube 92. The baffle 10 structurally limits the position of the marking slider 912 along the length direction of the viewing tube 92. Specifically, the axial spacing between two adjacent insertion holes 921 is designed to correspond to the total height of a single sub-magnetic core 71. At the same time, the axial spacing between the baffle 10 located at the uppermost or lowermost end and the end wall of the viewing tube 92 also corresponds to the total height of a single sub-magnetic core 71. The total height of the sub-magnetic core 71 includes not only the length of the magnetic material portion but also the thickness of the insulating connecting rings 713 at the upper and lower ends of the sub-magnetic core 71. This structural design allows the marker slider 912 to move a distance within the visible tube 92 each time, matching the length of a single sub-magnetic core 71. In other words, when adjusting the position of the magnetic core assembly 7, the user can sequentially pull out one or multiple baffles 10 from top to bottom or bottom to top, thereby controlling the marker slider 912 to move in steps along its length that are integer multiples of the sub-magnetic core 71. Simultaneously, the baffles 10 are relatively rigid and not easily bent by the resistance of the marker slider 912.

[0072] Understandably, the effect of this structural design is that when the magnetic core assembly 7 moves axially under the drive assembly 82, its movement distance is quantified as an integer multiple of the height of one or more sub-cores 71. This hierarchical step-by-step movement control method makes the movement result of each sub-core 71 controllable and clear. For example, after each adjustment, the sub-core 71 either enters the coil winding 6 entirely or exits the winding area entirely, thus preventing the sub-core 71 from partially entering or exiting the winding and causing its boundary to float in the critical region of the magnetic field. This effectively reduces the non-uniformity of magnetic flux coupling between the core and the coil, which to some extent helps to avoid magnetic flux leakage, maintains the concentration and uniformity of the magnetic field inside the coil, and thus maintains the stability of the system inductance.

[0073] In the above structure, the baffle 10 acts as a physical limiting element, controlling the movable stroke of the indicator slider 912 within the visual tube 92 by its insertion state at different positions of the socket 921. The movement of the indicator slider 912 corresponds one-to-one with the movement of the magnetic core assembly 7, thus reflecting the position of the sub-core 71 relative to the coil winding 6. Specifically, when the baffle 10 is not removed, the corresponding indicator slider 912 cannot cross that position, and further movement of the magnetic core assembly 7 is also restricted. Therefore, this structure has the function of precisely controlling the step length of the magnetic core assembly 7 each time, and also provides position visualization, which is beneficial for operators to flexibly adjust the insertion depth of the magnetic core assembly 7 according to the needs of on-site experiments. Furthermore, the baffle 10 has a simple structure, is easy to manufacture and replace, and combined with the scale marking system of the visual tube 92, it helps to achieve quantitative control, repeatable adjustment, and intuitive observation of the adjustment process of the magnetic core assembly 7, showing good application prospects in experimental teaching, debugging calibration, or process recording.

[0074] It should also be noted that the marking slider 912 is made of a high-density material, such as iron or steel, and is relatively heavy. When the magnetic core assembly 7 moves upward, the marking slider 912 will automatically fall from top to bottom within the visible tube 92 due to its own weight. Furthermore, since both the baffle 10 and the insulating connecting ring 713 have thickness, the moving position of the sub-magnetic core 71 may deviate slightly from the position of the marking slider 912, but this will not affect the final adjustment result. That is, after each adjustment, the sub-magnetic core 71 can either completely enter the coil winding 6 or completely exit the winding area.

[0075] In some implementations, combined with Figure 2 , Figure 3To address potential structural issues such as bending and wear that may occur when the connecting rope 911 is guided through the sliding channel 52 inside the housing 5, a smooth, rounded transition sliding track connection structure and a steering wheel 53 mechanism are implemented to reduce the risk of localized stress concentration during rope operation. Specifically, a rounded transition corner is provided at the connection between the vertical slide 522 and the horizontal slide, allowing the connecting rope 911 to slide along a smooth curved surface as it transitions from a vertical path to a horizontal direction, thus avoiding excessive bending or localized wear caused by sharp angles. A steering wheel 53 is provided between the port of the horizontal slide 521 in the housing 5 and the top wall of the visible tube 92. This steering wheel 53 can rotate around its own axis, and its surface slides in contact with the connecting rope 911. When the connecting rope 911 is tensioned or retracted during operation, the steering wheel 53 can adaptively rotate in the direction of rope movement, thereby reducing the coefficient of sliding friction and minimizing heat accumulation and material fatigue caused by friction. This structure can extend the service life of the connecting rope 911 to a certain extent, improve the smoothness of the sliding response and the measurement accuracy of the marking connecting component 91, and help ensure the long-term stable operation of the depth indicating mechanism.

[0076] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0077] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0078] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0079] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A series resonance experimental device, characterized by comprising: The application relates to a variable-frequency power supply (1), an excitation transformer (2), a reactor (4) and a voltage divider (3), wherein the output end of the variable-frequency power supply (1) is electrically connected with the input end of the excitation transformer (2), the output end of the excitation transformer (2) is electrically connected with the input end of the reactor (4), the reactor (4) is configured to be connected with a test product, and the voltage divider (3) is connected in series between the reactor (4) and the test product. The reactor (4) comprises a shell (5), a coil winding (6), a magnetic core assembly (7) and a driving mechanism (8), the shell (5) is configured to be vertically placed on the ground, the coil winding (6) is axially installed in the shell (5), the magnetic core assembly (7) is movably connected in the shell (5) in the axial direction, the magnetic core assembly (7) comprises a plurality of axially detachably connected sub-magnetic cores (71), and the driving mechanism (8) is installed on the shell (5) and configured to drive the magnetic core assembly (7) to move in the axial direction so that at least one of the sub-magnetic cores (71) is located in the coil winding (6). The driving mechanism (8) comprises a guide assembly (81) and a driving assembly (82), the guide assembly (81) is axially connected in the shell (5) and axially passes through the inner ring of the coil winding (6), a plurality of the sub-magnetic cores (71) are movably connected on the guide assembly (81) in the extension direction of the guide assembly (81), and the driving assembly (82) is configured to be in transmission connection with the guide assembly (81) so as to drive the plurality of sub-magnetic cores (71) to move in the axial direction. The reactor (4) further comprises a plurality of depth identification mechanisms (9) on the shell (5), each of the depth identification mechanisms (9) is connected with one of the sub-magnetic cores (71) and used for identifying the depth of the magnetic core assembly (7) into the coil winding (6). The depth identification mechanism (9) comprises an identification connecting assembly (91) and a visible tube (92), the visible tube (92) is coaxially installed on the outer wall of the shell (5), one end of the identification connecting assembly (91) is slidably connected in the visible tube (92), the other end is connected with the insulating connecting ring (713) of the sub-magnetic core (71), the visible tube (92) is provided with a scale mark in the length direction of the visible tube (92), and the scale mark value corresponding to the position of the identification connecting assembly (91) in the visible tube (92) is configured to indicate the depth of the magnetic core assembly (7) into the coil winding (6). The identification connecting assembly (91) comprises a connecting rope (911) and an identification slider (912), a sliding channel (52) is arranged in the top wall of the shell (5), the sliding channel (52) comprises a horizontal sliding channel (521) and a vertical sliding channel (522) connected in communication, one end of the horizontal sliding channel (521) away from the vertical sliding channel (522) is located above the top of the visible tube (92), one end of the vertical sliding channel (522) away from the horizontal sliding channel (521) is in axial communication with the shell (5), the identification slider (912) is slidably arranged in the visible tube (92), one end of the connecting rope (911) passes through the vertical sliding channel (522), the horizontal sliding channel (521) and the top wall of the visible tube (92) in sequence and is connected with the identification slider (912), and the other end of the connecting rope (911) extends axially along the shell (5) and is connected with the insulating connecting ring (713); when the insulating connecting ring (713) located at the lowermost end of the plurality of sub-magnetic cores (71) is attached to the lower surface of the bottom support frame (51) by the driving of the driving assembly (82), the identification slider (912) is attached to the inner top wall of the visible tube (92); when the insulating connecting ring (713) located at the uppermost end of the plurality of sub-magnetic cores (71) is attached to the inner top wall of the shell (5) by the driving of the driving assembly (82), the identification slider (912) is attached to the inner bottom wall of the visible tube (92); At least one insertion hole (921) is arranged on the wall of each visible tube (92) and transversely spaced along the length direction, the insertion hole (921) is used for inserting the baffle (10), the baffle (10) can limit the position of the identification slider (912) in the length direction of the visible tube (92) in structure, the axial spacing between the adjacent two insertion holes (921) is designed to correspond to the total height of a single sub-magnetic core (71), and the axial spacing between the baffle (10) located at the uppermost end or the lowermost end and the tube end wall of the visible tube (92) also corresponds to the total height of a single sub-magnetic core (71), wherein the total height of the sub-magnetic core (71) includes not only the length of the magnetic material part, but also the thickness of the insulating connecting ring (713) at the upper end and the lower end of the sub-magnetic core (71).

2. The series resonance experimental device according to claim 1, wherein The guiding assembly (81) comprises an insulating threaded rod (811) and an insulating guide rod (812), the insulating threaded rod (811) and the insulating guide rod (812) are coaxially connected in the shell (5) and axially pass through the inner ring of the coil winding (6), the sub-magnetic core (71) is axially provided with a threaded hole (711) and a guide hole (712), each sub-magnetic core (71) is threadedly connected with the insulating threaded rod (811) through the threaded hole (711), and each sub-magnetic core (71) is slidably connected with the insulating guide rod (812) through the guide hole (712); The insulating threaded rod (811) is rotationally connected with the shell (5), and the driving assembly (82) is used for driving the insulating threaded rod (811) to rotate.

3. The series resonance experimental device according to claim 2, wherein The driving assembly (82) comprises a driving rod (821), a rotating handle (822) and a driving bevel gear (823), the driving rod (821) is rotationally connected to the side wall of the shell (5) close to the ground, the rotating handle (822) is connected to one end of the driving rod (821) outside the shell (5), and the driving bevel gear (823) is coaxially connected to the other end of the driving rod (821) inside the shell (5); the driven bevel gear is coaxially connected to the rod wall close to the bottom of the insulating threaded rod (811), and the driven bevel gear is engaged with the driving bevel gear (823).

4. The series resonance experimental device according to claim 2, wherein The axial both ends of the sub-magnetic core (71) are provided with insulating connecting rings (713), the insulating connecting rings (713) on adjacent two sub-magnetic cores (71) are in close contact, the outer diameter of the insulating connecting ring (713) is larger than the outer diameter of the sub-magnetic core (71), a connecting screw hole (714) is penetratingly arranged on the insulating connecting ring (713), the connecting screw holes (714) on adjacent two insulating connecting rings (713) are axially opposite, and the ends, away from each other, of the adjacent two connecting screw holes (714) are provided with recesses (715), and the connecting bolts (716) are threadedly provided in the adjacent two connecting screw holes (714), and the nuts of the connecting bolts (716) are located in the recesses (715).

5. The series resonance experimental device according to claim 4, wherein The inner bottom wall of the shell (5) is provided with a bottom support frame (51), the insulating threaded rod (811) rotates through the bottom support frame (51), the lower end of the insulating guide rod (812) is fixedly connected to the bottom support frame (51), and the upper surface of the bottom support frame (51) is flush with the lower end surface of the coil winding (6). When the driving assembly (82) drives the insulating connecting ring (713) at the lowermost end of the plurality of sub-magnetic cores (71) to be attached to the lower surface of the bottom support frame (51), the upper surface of the insulating connecting ring (713) at the uppermost end of the plurality of sub-magnetic cores (71) is flush with the upper end surface of the coil winding (6). When the driving assembly (82) drives the insulating connecting ring (713) at the uppermost end of the plurality of sub-magnetic cores (71) to be attached to the inner top wall of the shell (5), the sub-magnetic core (71) at the lowermost end is located in the coil winding (6), and the upper surface of the insulating connecting ring (713) corresponding to the upper end of the sub-magnetic core (71) is flush with the upper end surface of the coil winding (6).

6. The series resonance experimental device according to claim 1, wherein The communication between the horizontal slide (521) and the vertical slide (522) is a round corner smooth transition fit, a steering wheel (53) is rotationally arranged between the port of the horizontal slide (521) and the top wall of the visual tube (92) on the shell (5), and the steering wheel (53) is configured to be in sliding contact with the connecting rope body (911).

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