Transformer core discharge detection device

Abstract

This invention relates to a transformer core discharge detection device, comprising a base; a clamping assembly mounted on the base for detachably clamping and fixing the part to be detected to the transformer core; a power extraction component disposed on the clamping assembly for extracting an electrical signal from the part to be detected; a first discharge electrode electrically connected to the power extraction component; a second discharge electrode disposed opposite to the first discharge electrode, forming a detection gap between them; a recording medium disposed between the first and second discharge electrodes to leave a trace when an abnormal discharge occurs; a discharge detection unit electrically connected to the second discharge electrode to detect abnormal discharge and output a trigger signal; a conveying mechanism driving the recording medium to move; the conveying mechanism electrically connected to the discharge detection unit, responding to the trigger signal and driving the recording medium forward a predetermined distance. This invention has a simple structure, is easy to install, and can intuitively record abnormal discharge events.

Description

Technical Field

[0001] This invention belongs to the field of power equipment testing technology, and particularly relates to a transformer core discharge detection device. Background Technology

[0002] Transformers are core equipment in power systems, and the grounding status of their cores directly affects their safe and stable operation. During transformer operation, the core typically needs to be reliably grounded through structures such as core grounding plates, grounding strips, and clamp connecting plates. If abnormal conditions such as insulation aging, loose connections, or local potential accumulation occur at these connection points, abnormal discharge phenomena may be induced. If not detected in time, this can range from affecting the transformer's operating status to causing local overheating, exacerbating insulation damage, or even equipment failure.

[0003] In existing technologies, there are three main methods for detecting discharge at transformer core grounding points. The first is manual inspection, where staff periodically visit the site to visually inspect the relevant parts using conventional instruments. However, this method lacks real-time performance, relies heavily on personnel experience, and struggles to capture transient discharge events. The second is detection using conventional electrical testing equipment, such as handheld discharge detectors. While these devices can detect relevant discharge signals, they typically require manual on-site data reading, making operation cumbersome and lacking continuous recording capabilities. The third is a complex online monitoring system. This system can automatically monitor and record data, but it is usually structurally complex, costly, and has a long installation period. For scenarios requiring targeted detection of localized locations such as core grounding plates or grounding strips, this system is too cumbersome and not conducive to widespread adoption.

[0004] In addition, existing detection devices are insufficient in terms of the intuitiveness of the detection results. Most devices only output electrical signal values ​​or alarm signals, and operators cannot intuitively know the distribution of discharge traces, which is not conducive to subsequent comparative analysis and trend judgment of discharge events. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a transformer core discharge detection device, which has a simple structure, is easy to install, and can intuitively record abnormal discharge events.

[0006] A transformer core discharge detection device, comprising:

[0007] Matrix;

[0008] A clamping assembly, mounted on the base, is used to detachably clamp and fix the part to be tested to the transformer core;

[0009] A power-collecting component, mounted on the clamping assembly, is used to extract electrical signals from the part to be detected;

[0010] The first discharge electrode is electrically connected to the power-taking component;

[0011] The second discharge electrode is disposed opposite to the first discharge electrode, and a detection gap is formed between the two.

[0012] A recording medium is placed between the first discharge electrode and the second discharge electrode to leave a trace when an abnormal discharge occurs;

[0013] The discharge detection unit is electrically connected to the second discharge electrode and is used to detect abnormal discharge and output a trigger signal.

[0014] The conveying mechanism is used to drive the recording medium to move; the conveying mechanism is electrically connected to the discharge detection unit, and responds to the trigger signal to drive the recording medium forward a predetermined distance.

[0015] The clamping assembly includes two clamping arms and an opening and closing drive mechanism that drives the two clamping arms to move closer or further apart.

[0016] The opening and closing drive mechanism includes a threaded rod and two nuts. The threaded rod has two sections of threads with opposite directions of rotation. The two nuts are threaded onto the two sections of threads respectively and are fixedly connected to the two clamping arms respectively.

[0017] The power-collecting component includes a power-collecting needle that can be moved and extended and an elastic element. Under the elastic force of the elastic element, the power-collecting needle can press against the surface of the part to be tested.

[0018] It also includes a gap adjustment mechanism, which is connected to the second discharge electrode and is used to adjust the size of the detection gap.

[0019] The gap adjustment mechanism includes a telescopic column, a lead screw, and a knob. The second discharge electrode is installed at the end of the telescopic column, the lead screw is threadedly connected to the telescopic column, and the knob is fixedly connected to the lead screw.

[0020] The conveying mechanism includes a take-up drum, a unfolding drum, and a motor. The recording medium is wound on the take-up drum, and after passing through the detection gap at the end, it is wound on the unfolding drum. The motor drives the unfolding drum to rotate. The output end of the discharge detection unit is electrically connected to the motor.

[0021] The take-up drum is mounted on a damping bearing, which provides a damping torque to the take-up drum to maintain the tension of the recording medium.

[0022] It also includes a positioning roller assembly, which includes at least one pair of positioning rollers disposed on both sides of the recording medium for guiding and limiting the recording medium as it passes through the detection gap.

[0023] The discharge detection unit has preset discharge determination conditions, which include at least a pulse amplitude threshold.

[0024] By employing the above technical solution, the present invention has at least the following beneficial effects:

[0025] Easy installation: With two openable clamping arms and a bidirectional threaded rod drive mechanism, it can be quickly clamped and fixed to the grounding part of the transformer core without disassembling or modifying the original equipment structure. Compared with the complicated installation methods of existing through-core sensors or online monitoring systems, it significantly improves the convenience of on-site testing.

[0026] The results are intuitive: By directly receiving the discharge and leaving physical traces such as ablation and carbonization on the recording film, the operator can visually determine whether an abnormal discharge has occurred and the distribution of the discharge. Compared with the existing technology that relies on electronic signal values ​​or waveform displays, this method achieves offline traceable physical recording, and the results are more intuitive.

[0027] Adjustable gap: The adjustable gap design between the opposing electrode plate and the conductive needle (telescopic column, lead screw, knob) allows for flexible adjustment of the detection sensitivity according to different detection needs, which improves the adaptability to different working conditions compared to the existing fixed gap structure.

[0028] Automatic linkage: After the pulse detection unit detects a valid abnormal discharge, it automatically outputs a drive signal to control the motor to drive the recording film forward a predetermined distance, realizing an integrated automatic closed loop of abnormal discharge events and recording medium segment switching. Compared with the existing technology that requires manual intervention or only stores electronic signals, it greatly improves the degree of automation and the continuity of segmented recording.

[0029] Compact structure: Integrating power supply guidance, gap adjustment, pulse detection, and conveyor mechanism into one unit, it is lightweight and lowers the configuration threshold, making it suitable for short-term on-site inspections and localized key inspection scenarios. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the transformer core discharge detection device of the present invention;

[0031] Figure 2 This is a schematic diagram of the clamping part of the transformer core discharge detection device of the present invention;

[0032] Figure 3 This is a schematic diagram of the internal structure of the transformer core discharge detection device of the present invention;

[0033] Figure 4 for Figure 3 A partially enlarged schematic diagram of the installation location of the electrocautery needle;

[0034] Figure 5 This is an exploded structural diagram of the recording film, take-up drum, unfolding drum, and positioning roller in this invention;

[0035] Figure 6This is an exploded structural diagram of the recording film, take-up drum, unfolding drum, and positioning roller in this invention;

[0036] Figure 7 This is a schematic diagram of the connection structure between the take-up drum and the unfolding drum in this invention;

[0037] In the picture:

[0038] 1. Detection box; 2. Clamping arm; 3. Clamping pad; 4. Adjustment cabinet; 5. Threaded rod; 6. Nut; 7. Connecting column; 8. Adjustment knob; 9. Slide rail; 10. Slide groove; 11. Electrode needle; 12. Pressure plate; 13. Spring; 14. Wire 1; 15. Conductive plate; 16. Wire 2; 17. Conductive needle; 18. Opposing electrode plate; 19. Telescopic column; 20. Fixing cylinder; 21. Lead screw; 22. Knob; 23. Recording film; 24. Rewind drum; 25. Unwind drum; 26. Damping bearing; 27. Left positioning roller; 28. Left fixing bracket; 29. ​​Right positioning roller; 30. Right fixing bracket; 31. Container box; 32. Top cover plate. Detailed Implementation

[0039] To better explain and facilitate understanding of the present invention, the technical solution and effects of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] Transformer core discharge detection device, such as Figures 1-7 As shown, it can be used for abnormal discharge detection in parts such as transformer core grounding plates, grounding strips, and clamp connecting plates.

[0041] Among them, such as Figure 1 As shown, the transformer core discharge detection device provided by the present invention includes a detection box 1. Two clamping arms 2 are movably mounted on one side of the detection box 1. Each clamping arm 2 has a clamping pad 3 on its opposite side. The two clamping arms 2 can move closer to or further away from each other, thereby clamping and fixing them to the transformer core's core grounding plate, grounding flat strip, or clamping connecting piece. Through the two clamping arms 2 that can open and close relative to each other, the entire detection device can be quickly installed at the location to be tested in a clamping manner without any disassembly or modification of the original transformer structure. It is easy to install and highly adaptable.

[0042] Furthermore, the clamping pad 3 is made of rubber, silicone, or other materials with a certain elasticity and coefficient of friction to enhance clamping stability and reduce damage to metal components. The clamping pad 3 improves the stability of the device after installation and reduces wear on the surfaces of transformer-related metal components caused by rigid clamping.

[0043] like Figure 2As shown, an adjusting cabinet 4 is fixedly installed on the detection box 1. A threaded rod 5 is rotatably installed inside the adjusting cabinet 4. The outer walls of the threaded rod 5 have left and right threads with opposite directions of rotation on both sides. Nuts 6 are threaded onto both the left and right threads, and the two nuts 6 are fixedly connected to the clamping arms 2 via two connecting posts 7. By controlling the rotation of the threaded rod 5, the two clamping arms 2 can be moved closer or further apart. One end of the threaded rod 5 is rotatably installed on the inner wall of the adjusting cabinet 4, and the other end extends to the outside of the adjusting cabinet 4 and is fixedly connected to an adjusting knob 8. Turning the adjusting knob 8 adjusts the rotation of the threaded rod 5, thereby driving the two nuts 6 to move synchronously in opposite directions, realizing the opening and closing of the clamping arms 2. The adjusting knob 8 can be configured as a hand-tightening knob or a nut head with a wrench interface for operator use.

[0044] like Figure 2 As shown, each of the two clamping arms 2 is provided with a slide rail 9 at one end near the detection box 1. The slide rail 9 is slidably installed in the slide groove 10 opened on the detection box 1. Through the cooperation of the slide rail 9 and the slide groove 10, the opening and closing movement of the clamping arms 2 can be guided and restricted, so that the clamping arms 2 can move smoothly in a predetermined direction, reducing the possibility of the clamping arms 2 tilting, shaking or jamming during clamping and releasing, thereby improving the smoothness and reliability of the clamping action. At the same time, the slide rail 9 and the slide groove 10 can also provide auxiliary support for the clamping arms 2, reducing the lateral force borne by the connecting column 7 alone, which is conducive to improving the overall structural strength and long-term stability.

[0045] like Figure 3 As shown, one of the slide rails 9 is a conductive rail, which is slidably connected to the conductive plate 15. The conductive plate 15 is connected to the conductive needle 17 via a second wire 16, and the conductive rail is connected to the power-taking needle 11 via a first wire 14. That is, one slide rail 9 also serves as a conductive rail, enabling it to guide the clamping arm 2 while also acting as part of the electrical signal transmission path. This achieves an integrated setup of the guiding structure and the conductive structure, reducing the number of individual conductive connectors and making the overall structure more compact. After the conductive plate 15 is slidably connected to the conductive rail, when the clamping arm 2 moves relative to the detection box 1, the conductive plate 15 can slide smoothly along the conductive rail, thus maintaining the conductive connection without affecting the movement of the clamping arm 2 and preventing the power-taking circuit from being interrupted due to changes in the position of the clamping arm 2.

[0046] like Figure 4As shown, a slot is formed in the clamping pad 3 of the clamping arm 2, which is equipped with a conductive rail, and the power-collecting needle 11 is movably extended and retracted within the slot. Specifically, a pressure plate 12 is fixedly installed on the outer wall of the power-collecting needle 11. The pressure plate 12 is movably disposed within a slot formed inside the clamping arm 2 and is supported by a spring 13, thereby allowing the power-collecting needle 11 to elastically extend and retract. Furthermore, the power-collecting needle 11 is made of a metal part with good conductivity and a certain degree of wear resistance at the end, such as copper or copper alloy. At the same time, the front end of the power-collecting needle 11 is set as an arc head, a conical head, or other shape suitable for contacting metal parts. Through the cooperation of the pressure plate 12 and the spring 13, the power-collecting needle 11 retracts inward when squeezed by the clamped part, and continues to push outward under the elastic force of the spring 13, thereby automatically adapting to iron core grounding plates, grounding flat strips, or clamping connecting plates of different thicknesses and surface positions, improving contact stability. At the same time, this elastic telescopic structure can also play a buffering role during the clamping process, preventing the electrode 11 from damaging the surface of the part to be tested due to excessive rigid pressure.

[0047] When the two clamping arms 2 are clamped on the core grounding plate, grounding flat strip, clamping connecting plate and other structures of the transformer core, the power taking needle 11 takes power and transmits the electrical signal to the conductive needle 17 in sequence through the first conductor 14, the conductive rail, the conductive plate 15 and the second conductor 16. The conductive needle 17 can then serve as one conductive end in the detection area.

[0048] like Figure 5As shown, the transformer core discharge detection device further includes a counter electrode 18 opposite to the conductive needle 17. The counter electrode 18 is mounted at the end of the telescopic column 19, which is movably telescopically positioned within the fixed cylinder 20. Specifically, the telescopic column 19 is slidably mounted within the fixed cylinder 20 via a spline structure and threadedly connected to a lead screw 21; the lead screw 21 is rotatably mounted within the fixed cylinder 20, with one end extending to the outside of the detection box 1 and connected to a knob 22. By rotating the knob 22, the lead screw 21 is rotated, driving the telescopic column 19 to move axially within the fixed cylinder 20, thereby adjusting the distance between the counter electrode 18 and the conductive needle 17. The operator can adjust the distance between the counter electrode 18 and the conductive needle 17 according to the detection requirements to form different sizes of detection gaps. When the detection gap is small, the device has a high response sensitivity to weak abnormal discharge pulses; when the detection gap is appropriately increased, it can avoid oversensitivity and false triggering. This adjustable structure can improve the device's adaptability to different operating conditions. Preferably, the opposing electrode 18 is made of a metal sheet with good conductivity and a smooth surface, such as stainless steel or copper. When the opposing electrode 18 and the conductive needle 17 are positioned opposite each other, a clear detection area is formed between them. An open air gap is formed between the conductive needle 17 and the opposing electrode 18, which is the detection area. When a high potential appears on the conductive needle 17 due to abnormal discharge, a breakdown discharge occurs in the air gap. The discharge current passes through the recording chip 23 located between them, leaving a visible trace on the recording chip 23, which helps to concentrate the abnormal discharge signal at a predetermined location.

[0049] The transformer core discharge detection device also includes a pulse detection unit 33, which is electrically connected to the opposing electrode plate 18. The opposing electrode plate 18 serves as a signal acquisition terminal, transmitting pulse signals within the detection area to the pulse detection unit 33. The pulse detection unit 33 detects and determines the acquired pulse signals. The pulse detection unit 33 presets a pulse amplitude threshold or equivalent comparison condition according to actual needs. When the detected pulse signal reaches the preset condition, it is determined that a valid abnormal discharge has occurred, and a drive signal is output.

[0050] like Figures 5-6As shown, a recording sheet 23 is positioned between the opposing electrode 18 and the conductive needle 17. The recording sheet 23 is wound onto a take-up spool 24 with its end extended. After passing between the opposing electrode 18 and the conductive needle 17, it is wound onto a unfolding spool 25. The take-up spool 24 is mounted on a damping bearing 26, and the unfolding spool 25 is driven to rotate by a motor. The angle of each rotation is set as needed, thereby positioning the recording sheet 23 at different positions between the electrode 18 and the conductive needle 17. The recording sheet 23, as a recording medium for receiving discharge and leaving corresponding traces, is preferably a flexible sheet structure for winding, storage, and continuous segmented use. The material of the recording sheet 23 can be selected according to actual needs, such as paper-based recording paper, thermal paper, or other flexible materials that can be ablated and left with traces by discharge. The recording film 23 passes through the detection area between the conductive needle 17 and the opposing electrode plate 18. When an abnormal discharge occurs in this area, the discharge effect can leave ablation points, carbonization points, burn marks, or discoloration marks on the corresponding section of the recording film 23 currently located in the detection area. The operator only needs to check the corresponding section of the recording film 23 to determine whether an abnormal discharge has occurred and the general situation of the discharge. The take-up drum 24 is installed through a damping bearing 26, which provides a continuous and stable damping torque to the take-up drum 24 to prevent excessive rotation due to inertia and ensure that the recording film 23 is always in a taut state. The unfolding drum 25 is driven to rotate by a motor. Preferably, it rotates by a fixed angle each time after the pulse detection unit outputs a trigger signal, so that the recording film 23 advances segment by segment according to a predetermined length, allowing new blank segments to enter the detection area; the segments that have been subjected to discharge are rolled away from the detection area, thereby realizing the segmented recording of abnormal discharge events, which is convenient for subsequent viewing and comparative analysis.

[0051] Furthermore, such as Figure 5As shown, a left positioning roller 27 is provided on one side of the recording film 23, and the left positioning roller 27 is fixedly mounted on the telescopic column 19 via a left fixing bracket 28; at the same time, a right positioning roller 29 is provided on the other side of the recording film 23, and the right positioning roller 29 is fixedly mounted on the telescopic column 19 via a right fixing bracket 30. Preferably, the left positioning roller 27 and the right positioning roller 29 are arranged one above the other, with the opposing area located between them. The left positioning roller 27 and the right positioning roller 29 can guide and limit the recording film 23 as it passes through the detection area, so that the recording film 23 maintains a relatively stable path when it enters between the conductive needle 17 and the opposing electrode plate 18, reducing the possibility of the recording film 23 shifting, wrinkling, hanging, or loosening in the detection area, which is beneficial to ensuring that the discharge trace is stably formed at the predetermined recording position. The left positioning roller 27 and the right positioning roller 29 are arranged in an up-down configuration, creating a relatively stable guide zone for the recording film 23 between them. This not only limits the path of the recording film 23 in a clamping manner but also ensures good flatness of the recording film 23 in the detection area, improving the consistency of the recording effect. Since both the left positioning roller 27 and the right positioning roller 29 are mounted on the telescopic column 19, when the position of the telescopic column 19 is adjusted by the knob 22, i.e., the distance between the opposing electrode plate 18 and the conductive needle 17 is adjusted, the left positioning roller 27 and the right positioning roller 29 will also move synchronously as a whole. This ensures that the guide position of the recording film 23 always corresponds to the detection area, which helps to improve the coordination of the entire detection mechanism after adjustment.

[0052] Furthermore, the unfolding cylinder 25 and the motor are housed within the receiving box 31, which is connected to the detection box 1. The receiving box 31 provides protection for the unfolding cylinder 25 and the motor, while also facilitating unified disassembly and maintenance. The motor is selected as a stepper motor or other micro motor capable of rotating in predetermined angles; specific parameters can be determined based on torque and accuracy requirements.

[0053] like Figure 7 As shown, the take-up drum 24 and the damping bearing 26, as well as the unfolding drum 25 and the motor, are connected by a prism groove and prism engagement. This connection method ensures the transmission reliability of the take-up drum 24 and the unfolding drum 25 after installation, and also facilitates quick disassembly and replacement of the drum body or maintenance of internal components when the recording film 23 is exhausted, thus improving maintenance convenience. Meanwhile, a top cover 32 is detachably installed at a corresponding position on the top surface of the inspection box 1. The top cover 32 can be freely opened to allow operators to inspect internal components or replace the recording film 23.

[0054] The output of the pulse detection unit 33 is electrically connected to the motor. When the pulse detection unit 33 detects a valid abnormal discharge pulse, its output terminal outputs a drive signal. This drive signal controls the motor to start and rotate by a preset angle. The motor shaft drives the unfolding tube 25 to rotate by the same angle, thereby pulling the recording film 23 out of the take-up drum 24 by a predetermined length. This moves the recorded section that has been affected by the discharge away from the detection area, while simultaneously moving a new blank recorded section between the conductive needle 17 and the opposing electrode plate 18, ready for recording during the next abnormal discharge. Through the above electrical connection and signal control relationship, the pulse detection unit 33 achieves automatic control of the motor and the unfolding tube 25, thereby realizing automatic linkage between the abnormal discharge event and the recording film section changing action. This eliminates the need for manual intervention, avoids continuous manual observation, and improves the convenience of detection and recording.

[0055] In actual use, the operator first opens the two clamping arms 2 to a suitable distance by rotating the adjustment knob 8, and then places the clamping arms 2 onto both sides of the transformer core grounding plate, grounding flat strip, or clamping connecting plate to be tested. Then, the operator rotates the adjustment knob 8 in the opposite direction to gradually clamp the area to be tested. During clamping, the electro-electrode 11 is pressed against the surface of the metal structure to be tested by the spring 13, drawing out the electrical signal at that location and transmitting it to the conductive needle 17 via the first wire 14, conductive rail, conductive plate 15, and the second wire 16. Then, the operator rotates the knob 22 to adjust the detection gap between the opposing electrode plate 18 and the conductive needle 17 according to the testing requirements. After the device is started, when an abnormal discharge occurs in the detection area, the pulse detection unit 33 collects the corresponding pulse signal, leaving an ablation mark on the corresponding section of the recording film 23. Simultaneously, the pulse detection unit 33 sends a drive signal to cause the motor to rotate the unfolding cylinder 25, bringing the new recording film section into the detection area, completing one automatic section change and recording. After the test is completed, the operator takes out the recording film 23 and can intuitively understand the occurrence and severity of the discharge event by observing the distribution of traces on the recording film 23.

Claims

1. A transformer core discharge detection device, characterized by, include: Matrix; A clamping assembly, mounted on the base, is used to detachably clamp and fix the part to be tested to the transformer core; A power-collecting component, mounted on the clamping assembly, is used to extract electrical signals from the part to be detected; The first discharge electrode is electrically connected to the power-taking component; The second discharge electrode is disposed opposite to the first discharge electrode, and a detection gap is formed between the two. A recording medium is placed between the first discharge electrode and the second discharge electrode to leave a trace when an abnormal discharge occurs; The discharge detection unit is electrically connected to the second discharge electrode and is used to detect abnormal discharge and output a trigger signal. The conveying mechanism is used to drive the recording medium to move; the conveying mechanism is electrically connected to the discharge detection unit, and responds to the trigger signal to drive the recording medium forward a predetermined distance.

2. The transformer core discharge detection apparatus according to claim 1, characterized by: The clamping assembly includes two clamping arms and an opening and closing drive mechanism that drives the two clamping arms to move closer or further apart.

3. The transformer core discharge detection apparatus according to claim 2, characterized by: The opening and closing drive mechanism includes a threaded rod and two nuts. The threaded rod has two sections of threads with opposite directions of rotation. The two nuts are threaded onto the two sections of threads respectively and are fixedly connected to the two clamping arms respectively.

4. The transformer core discharge detection apparatus according to claim 1, characterized by: The power-collecting component includes a power-collecting needle that can be moved and extended and an elastic element. Under the elastic force of the elastic element, the power-collecting needle can press against the surface of the part to be tested.

5. The transformer core discharge detection apparatus according to claim 1, characterized by: It also includes a gap adjustment mechanism, which is connected to the second discharge electrode and is used to adjust the size of the detection gap.

6. The transformer core discharge detection apparatus according to claim 5, characterized by: The gap adjustment mechanism includes a telescopic column, a lead screw, and a knob. The second discharge electrode is installed at the end of the telescopic column, the lead screw is threadedly connected to the telescopic column, and the knob is fixedly connected to the lead screw.

7. The transformer core discharge detection apparatus according to claim 1, characterized by: The conveying mechanism includes a take-up drum, a unfolding drum, and a motor. The recording medium is wound on the take-up drum, and after passing through the detection gap at the end, it is wound on the unfolding drum. The motor drives the unfolding drum to rotate. The output end of the discharge detection unit is electrically connected to the motor.

8. The transformer core discharge detection apparatus according to claim 7, characterized by: The take-up drum is mounted on a damping bearing, which provides a damping torque to the take-up drum to maintain the tension of the recording medium.

9. The transformer core discharge detection device according to claim 1, characterized in that: It also includes a positioning roller assembly, which includes at least one pair of positioning rollers disposed on both sides of the recording medium for guiding and limiting the recording medium as it passes through the detection gap.

10. The transformer core discharge detection device according to claim 1, characterized in that: The discharge detection unit has preset discharge determination conditions, which include at least a pulse amplitude threshold.

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