A nanocrystalline current transformer with DC component resistance and its use method

Abstract

The present invention discloses a nanocrystalline current transformer with DC component resistance and a method for using the same, comprising: a current transformer having a magnetic core hole extending from front to back in the middle of the front side of the current transformer. The device is provided with a secondary-side disconnection detection and protection mechanism, which effectively prevents the internal magnetic field imbalance of the transformer caused by the disconnection of the secondary circuit, avoids the core magnetic flux saturation and the generation of potential high electromotive force, thereby protecting the transformer itself and peripheral equipment, and reducing the risk of power system failures such as fire or short circuit. At the same time, a live conductor centering fixing mechanism is provided to ensure the stable centering position of the conductor in the transformer core hole, optimize the magnetic field distribution, reduce magnetic leakage, significantly improve the accuracy and stability of current measurement, and reduce measurement fluctuations introduced by conductor shaking, providing more accurate data support for harmonic analysis, fault detection, and power quality monitoring of the power system.

Description

Technical Field

[0001] The present invention relates to the technical field of current transformers, and in particular to a nanocrystalline current transformer capable of resisting direct current components and a method for using the same. Background Art

[0002] In power systems, current transformers, as key measurement and protection equipment, are responsible for converting large currents into smaller currents proportionally for use in measuring instruments, relay protection devices, and automatic control devices. In recent years, with the rapid development of materials science and power electronics technology, nanocrystalline materials have been widely used in the manufacture of current transformers due to their excellent magnetic properties, such as high saturation magnetic induction, low loss, and good temperature stability. In particular, nanocrystalline current transformers with DC immunity have become the preferred solution in power systems due to their unique advantages in suppressing DC interference and improving measurement accuracy.

[0003] As the name suggests, nanocrystalline current transformers with DC immunity leverage the unique magnetic properties of nanocrystalline alloy materials to effectively filter out the DC component in current signals, thereby ensuring the accuracy and stability of measurement results. This characteristic is of great significance for harmonic analysis, fault detection, and power quality monitoring in power systems. However, despite significant technological progress in DC-resistant nanocrystalline current transformers, practical applications still face urgent technical challenges.

[0004] First, the design of conventional nanocrystalline current transformers designed to withstand DC components often overlooks the importance of secondary-side open-circuit detection and protection mechanisms. During normal operation, the secondary side of a current transformer must remain closed to ensure proper current conversion and transmission. If the secondary side becomes open during operation due to loose terminals, broken secondary cables, or poor contact between relays or contactors, the secondary circuit is disconnected. This directly leads to an imbalance in the transformer's internal magnetic field, converting almost entirely the primary current into the excitation current, which in turn causes severe saturation of the core's magnetic flux. In this state, extremely high electromotive forces can be generated across the transformer, potentially damaging the transformer itself and posing a serious threat to surrounding equipment and even the safety of operators. Furthermore, oversaturation of the core significantly increases its losses, causing severe heating, which can burn the transformer or break the secondary winding insulation, potentially triggering wider power system failures such as fire or short circuits. Especially if left untreated for an extended period, the transformer casing can melt due to the high temperature, exposing the core and further exacerbating the dangers of the accident.

[0005] Secondly, the existing nanocrystalline current transformers that are resistant to DC components have another design shortcoming, namely the lack of an effective mechanism for centering the live conductor. During actual installation and use, the live conductor is usually directly inserted into the core hole of the transformer, lacking the necessary fixing measures. This design not only fails to ensure the stability of the conductor position, but also makes it difficult to ensure that the conductor is always located in the center of the core hole. The position deviation of the conductor will directly affect the uniform distribution of the magnetic field, resulting in an increase in magnetic leakage. The intensification of magnetic leakage means that the transformer's ability to capture current changes in the conductor is reduced, and the measurement accuracy is reduced accordingly. In addition, the unstable conductor position may also cause shaking due to vibration or external force during the operation of the transformer. This shaking will further introduce measurement fluctuations, further weakening the stability and accuracy of the measurement. Summary of the Invention

[0006] The object of the present invention is to provide a nanocrystalline current transformer with DC component resistance and a method of using the same, so as to at least solve the problem in the prior art that the position of the conductor cannot be fixed due to potential safety hazards.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a nanocrystalline current transformer with DC component resistance, comprising: a current transformer, a magnetic core hole extending from front to back is provided in the middle of the front side of the current transformer; a second terminal is arranged on the left side of the bottom end of the front side of the current transformer; a first terminal is arranged on the right side of the bottom end of the front side of the current transformer; a monitoring and protection mechanism is arranged in the middle of the bottom end of the front side of the current transformer; and a centering positioning mechanism is arranged on the front side of the current transformer.

[0008] Preferably, the monitoring and protection mechanism includes: a connecting piece, two connecting pieces are respectively arranged on the outer walls of the first terminal and the second terminal, and the connecting piece is electrically connected to the first terminal and the second terminal; one end of the second wire is arranged on the inner side of the connecting piece, and the second wire and the connecting piece are electrically connected; the positive pole of the speaker is electrically connected to the other end of the second wire on the right; the negative pole of the warning light is electrically connected to the other end of the second wire on the left; there are two first wires, one end of one first wire is electrically connected to the negative pole of the speaker, and one end of the other first wire is electrically connected to the positive pole of the warning light; the second contact is arranged at the other end of the first wire on the right; the first contact is arranged at the other end of the first wire on the left.

[0009] Preferably, in order to promote the conduction of the circuit of the first terminal and the second terminal, the monitoring and protection mechanism also includes: a protection box, the protection box is arranged at the middle of the bottom end of the front side of the current transformer, and a movable groove connected to its inner cavity is opened in the middle of the front side of the protection box along the up and down direction, and the left and right ends of the middle of the front side of the inner cavity of the protection box are both provided with sliding grooves in the left and right directions; the second support plate is arranged at the middle of the top end of the front side of the inner cavity of the protection box, and the first contact and the second contact are both arranged at the bottom end of the second support plate; the number of fourth guide rods is two, the top ends of the two fourth guide rods are respectively arranged at the front and back sides of the middle of the bottom end of the second support plate, and the bottom ends of the two fourth guide rods are both arranged at the bottom end of the inner cavity of the protection box; the insulating block is slidably connected to the middle of the outer wall of the fourth guide rod; the conductive sheet is arranged at the top end of the insulating block, and the conductive sheet is slidably connected to the outer wall of the fourth guide rod; the second spring is connected to the bottom end of the outer wall of the fourth guide rod, the top end of the second spring is clamped to the bottom end of the insulating block, and the bottom end of the second spring is clamped to the bottom end of the inner cavity of the protection box.

[0010] Preferably, in order to drive the insulating block to move, the monitoring and protection mechanism also includes: a permanent magnet, the number of which is two, and the two permanent magnets are respectively arranged on the left and right sides of the bottom end of the insulating block; a power-off type electromagnet, the number of which is two, and the two power-off type electromagnets are respectively arranged on the left and right ends of the middle of the front side of the inner cavity of the protection box, the top ends of the two power-off type electromagnets are respectively in contact with the bottom ends of the two permanent magnets, the power-off type electromagnets and the permanent magnets are of the same polarity and repel each other, the positive pole of one power-off type electromagnet is electrically connected to the negative pole of the other power-off type electromagnet, and the negative pole of the power-off type electromagnet is electrically connected to the second terminal.

[0011] Preferably, in order to push the insulating block to move, the monitoring and protection mechanism also includes: a first support plate, the number of the first support plates is two, and the two first support plates are respectively arranged at the upper and lower ends of the middle part of the front side of the inner cavity of the protection box; the number of the third guide rods is two, and the upper and lower ends of the two third guide rods are respectively arranged at the left and right ends of the inner sides of the two first support plates; the moving block can be slidably sleeved on the bottom end of the outer wall of the third guide rod; the sliding column is arranged in the middle of the front side of the moving block, and the front end of the sliding column can slidably extend out of the bottom end of the inner cavity of the moving groove; the push rod is arranged on the rear side of the moving block, and the top end of the push rod and The bottom ends of the insulating blocks are in contact with each other; there are two connecting rods, and one end of the two connecting rods is rotatably set on the left and right sides of the moving block through a pin shaft; the slider is rotatably set on the other end of the connecting rod through a pin shaft, and the two sliders are slidably adapted and inserted into the inner sides of the inner cavities of the two slide grooves; the left and right ends of the second guide rod are respectively set on the left and right sides of the inner cavity of the slide groove, and the slider is slidably connected to the outer wall of the second guide rod; the first spring is connected to the outer side of the outer wall of the second guide rod, one end of the first spring is clamped to the inner wall of the slide groove, and the other end of the first spring is clamped to the outer wall of the slider.

[0012] Preferably, in order to center and clamp the live wire, the centering positioning mechanism includes: a gear plate, there are two gear plates, the two gear plates are rotatably arranged on the front and rear sides of the current transformer through bearings, and the front side of the gear plate is provided with a plurality of drive grooves that pass through it at equal distances along the circumference; a positioning plate is sleeved on the outer wall of the current transformer, the gear plate is located in the inner cavity of the positioning plate, and the outer wall of the positioning plate is provided with a plurality of telescopic grooves connected to its inner cavity at equal distances along the circumference on both the front and rear sides, and the inner cavity of the positioning plate is provided with a plurality of limiting grooves connected to the inner cavity of the telescopic groove at equal distances along the circumference on both the front and rear sides, and the positions of the plurality of limiting grooves correspond one to one to the positions of the plurality of driving grooves; the clamping plate is slidably embedded in the inner cavity of the telescopic groove; the driving column is provided at the inner outer end of the clamping plate, and the outer wall of the driving column can slidably pass through the outer side of the inner cavity of the limiting groove, and can slidably extend into the outer side of the inner cavity of the driving groove.

[0013] Preferably, in order to drive the gear plate to rotate, the centering positioning mechanism also includes: a first guide rod, the number of the first guide rods is two, and the two first guide rods are respectively arranged at the front and rear ends of the top right side of the current transformer; the bottom end of the screw rod is rotatably arranged in the middle part of the top right side of the current transformer through a bearing; the rack plate is slidably sleeved on the top of the outer wall of the first guide rod, the rack plate is screwed to the outer wall of the screw rod, and the rack plate and the two gear plates are meshed.

[0014] Preferably, the distance between the upper and lower ends of the inner cavity of the movable slot is greater than the distance from the top of the conductive sheet to the bottom ends of the first contact and the second contact.

[0015] The present invention proposes a nanocrystalline current transformer with DC component resistance and a method of using the same, which has the following beneficial effects:

[0016] 1. The present invention utilizes a current transformer to convert a large current into a small current in proportion. By rotating the screw, the rack plate is driven to move downward, and the rack plate can be used to drive the gear plate to rotate clockwise. The driving column can be used to drive the clamping plate to move inward by utilizing the cooperation between the driving groove and the limit groove, and the clamping plate can be used to fix the live wire in the center of the inner cavity of the magnetic core hole, thereby ensuring that the magnetic field generated by the wire can pass through the current transformer more evenly, reducing the leakage magnetic phenomenon caused by the deviation of the wire position from the center.

[0017] 2. The present invention can prevent an open circuit between the first terminal and the second terminal by causing the conductive sheet to contact the first contact and the second contact. By utilizing the principle of like-charged repulsion between a de-energized electromagnet and a permanent magnet or by causing an upward sliding block to drive the push rod upward, the insulating block can drive the conductive sheet to move upward, thereby causing the conductive sheet to contact the first contact and the second contact.

[0018] 3. This device is equipped with a secondary side circuit breaker detection and protection mechanism, which effectively prevents the internal magnetic field imbalance of the transformer caused by the disconnection of the secondary circuit, avoids the core magnetic flux saturation and the generation of potential high electromotive force, thereby protecting the safety of the transformer itself and peripheral equipment, and reducing the risk of power system failures such as fire or short circuit. At the same time, a live conductor centering fixing mechanism is provided to ensure the stable center position of the conductor in the transformer core hole, optimize the magnetic field distribution, reduce magnetic leakage, significantly improve the accuracy and stability of current measurement, and reduce the measurement fluctuation introduced by the conductor shaking, providing more accurate data support for harmonic analysis, fault detection and power quality monitoring of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the present invention;

[0020] Figure 2 An exploded view of the present invention;

[0021] Figure 3 It is a schematic diagram of the structure of the inner cavity of the protection box;

[0022] Figure 4 Explosion diagram for monitoring protection agencies;

[0023] Figure 5 Schematic diagram of the structure of a permanent magnet;

[0024] Figure 6 for Figure 2 A magnified view of point A;

[0025] Figure 7 for Figure 2 Enlarged view of point B;

[0026] Figure 8 for Figure 4 Enlarged view of point C;

[0027] Figure 9 for Figure 5 Enlarged view of point D;

[0028] Figure 10 for Figure 5 Enlarged view of point E.

[0029] In the figure: 1, current transformer; 2, magnetic core hole; 3, second terminal; 4, first terminal; 5, monitoring and protection mechanism; 51, protection box; 52, moving slot; 53, slide slot; 54, second guide rod; 55, first spring; 56, first support plate; 57, third guide rod; 58, moving block; 59, slide column; 510, push rod; 511, connecting rod; 512, slider; 513, second support plate; 514, fourth guide rod; 515, conductive sheet; 516, insulating block; 5 17. Second spring; 518. Power-off electromagnet; 519. First contact; 520. Second contact; 521. First wire; 522. Warning light; 523. Speaker; 524. Second wire; 525. Connecting piece; 526. Permanent magnet; 6. Centering mechanism; 61. Gear plate; 62. Drive slot; 63. Positioning plate; 64. Telescopic slot; 65. Limiting slot; 66. Clamping plate; 67. Drive column; 68. First guide rod; 69. Screw; 610. Rack plate. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] See also Figure 1-10 The present invention provides a technical solution of a nanocrystalline current transformer with DC component resistance and a method for using the same, comprising: a current transformer 1, a magnetic core hole 2, a second terminal 3, a first terminal 4, a monitoring and protection mechanism 5, and a centering positioning mechanism 6. A magnetic core hole 2 running through the front and back is provided in the middle of the front side of the current transformer 1. The current transformer 1 is a prior art and will not be described in detail here. The current transformer 1 is used to convert a large current into a small current. The second terminal 3 is arranged on the left side of the bottom end of the front side of the current transformer 1, and the first terminal 4 is arranged on the right side of the bottom end of the front side of the current transformer 1. The monitoring and protection mechanism 5 is arranged in the middle of the bottom end of the front side of the current transformer 1. The monitoring and protection mechanism 5 is used to monitor whether there is an open circuit between the first terminal 4 and the second terminal 3. If an open circuit occurs, it is used to promote the circuit conduction between the first terminal 4 and the second terminal 3. The centering positioning mechanism 6 is arranged on the front side of the current transformer 1. The centering positioning mechanism 6 is used to fix the live wire at the center of the magnetic core hole 2.

[0032] As a preferred solution, further, the monitoring and protection mechanism 5 includes: a protection box 51, a movable groove 52, a slide groove 53, a second guide rod 54, a first spring 55, a first support plate 56, a third guide rod 57, a movable block 58, a slide column 59, a push rod 510, a connecting rod 511, a slider 512, a second support plate 513, a fourth guide rod 514, a conductive sheet 515, an insulating block 516, a second spring 517, a power-off type electromagnet 518, a first contact 519, a second contact 520, a first wire 521, a warning light 522, a speaker 523, a second wire 524, a connecting piece 525 and a permanent magnet 526. The number of the connecting pieces 525 is two, and the two connecting pieces 525 are respectively arranged on the first terminal 4 and the second terminal 3, the connecting piece 525 is electrically connected to the first terminal 4 and the second terminal 3, one end of the second wire 524 is arranged on the inner side of the connecting piece 525, the second wire 524 and the connecting piece 525 are electrically connected, the positive pole of the speaker 523 is electrically connected to the other end of the second wire 524 on the right side, the speaker 523 is a prior art, and no more details are given here. The speaker 523 is used to remind the staff to perform maintenance and transmit the signal to the main control center. The negative pole of the warning light 522 is electrically connected to the other end of the second wire 524 on the left side, the warning light 522 is a prior art, and no more details are given here. The warning light 522 is used here to remind the staff. The number of the first wire 521 is two, one of which is a first wire One end of the wire 521 is electrically connected to the negative pole of the speaker 523, and one end of the other first wire 521 is electrically connected to the positive pole of the warning light 522. The second contact 520 is provided at the other end of the first wire 521 located on the right, and the first contact 519 is provided at the other end of the first wire 521 located on the left. The protection box 51 is provided at the middle of the front bottom end of the current transformer 1. A movable groove 52 connected to its inner cavity is provided in the middle of the front side of the protection box 51 along the up and down directions. Slide grooves 53 are provided at the left and right ends of the inner cavity of the protection box 51 along the left and right directions. The distance between the upper and lower ends of the inner cavity of the movable groove 52 is greater than the distance from the top of the conductive sheet 515 to the bottom of the first contact 519 and the second contact 520, so as to ensure that the conductive sheet 515 can The second support plate 513 is arranged at the middle of the top of the front side of the inner cavity of the protection box 51, and the first contact 519 and the second contact 520 are both arranged at the bottom end of the second support plate 513. There are two fourth guide rods 514. The top ends of the two fourth guide rods 514 are respectively arranged at the front and back sides of the middle of the bottom end of the second support plate 513. The bottom ends of the two fourth guide rods 514 are both arranged at the bottom end of the inner cavity of the protection box 51. The insulating block 516 is slidably connected to the middle of the outer wall of the fourth guide rod 514. The conductive sheet 515 is arranged at the top of the insulating block 516. The conductive sheet 515 is slidably connected to the outer wall of the fourth guide rod 514. When the conductive sheet 515 contacts the first contact 519 and the second contact 520,It can promote the circuit conduction of the first terminal 4 and the second terminal 3. The second spring 517 is sleeved on the bottom end of the outer wall of the fourth guide rod 514. The top end of the second spring 517 is clamped on the bottom end of the insulating block 516. The bottom end of the second spring 517 is clamped on the bottom end of the inner cavity of the protective box 51. The second spring 517 is a rotary spring. It undergoes elastic deformation after being squeezed or stretched by external force, and returns to its initial state after the external force is removed. The second spring 517 is used here to support the insulating block 516. The number of permanent magnets 526 is two, and the two permanent magnets 526 are respectively arranged on the left and right sides of the bottom end of the insulating block 516. The permanent magnets 526 are prior art and will not be described in detail here. The number of power-off electromagnets 518 is two, and the two power-off electromagnets 518 are respectively Arranged at the left and right ends of the middle of the front side of the inner cavity of the protection box 51, the tops of the two power-off type electromagnets 518 are in contact with the bottom ends of the two permanent magnets 526 respectively, and the power-off type electromagnets 518 and the permanent magnets 526 are like-charged and repel each other. The positive pole of one power-off type electromagnet 518 is electrically connected to the negative pole of the other power-off type electromagnet 518, and the negative pole of the power-off type electromagnet 518 is electrically connected to the second terminal 3. The power-off type electromagnet 518 is a prior art. After the power-off type electromagnet 518 is energized, the magnetism disappears, and after the power is cut off, the magnetism recovers. The power-off type electromagnet 518 is used here to drive the insulating block 516 to drive the conductive sheet 515 to move upward based on the principle of like-charged repulsion between the electromagnet 518 and the permanent magnet 526. The number of the first support plates 56 is two, and the two The first support plate 56 is respectively arranged at the upper and lower ends of the middle part of the front side of the inner cavity of the protection box 51, and the number of the third guide rods 57 is two. The upper and lower ends of the two third guide rods 57 are respectively arranged at the left and right ends of the inner sides of the two first support plates 56. The moving block 58 is slidably sleeved on the bottom end of the outer wall of the third guide rod 57. The sliding column 59 is arranged in the middle of the front side of the moving block 58. The front end of the sliding column 59 can slidably extend out of the bottom end of the inner cavity of the moving groove 52. The push rod 510 is arranged on the rear side of the moving block 58. The top end of the push rod 510 contacts the bottom end of the insulating block 516. The push rod 510 is used to push the insulating block 516 to drive the conductive sheet 515 to move upward. The number of the connecting rods 511 is two, and one end of the two connecting rods 511 is rotatably arranged on the moving block 58 through a pin shaft. On the left and right sides of the movable block 58, the slider 512 is rotatably set at the other end of the connecting rod 511 through a pin shaft. The two sliders 512 are slidably adapted and inserted into the inner sides of the inner cavities of the two slide grooves 53. The left and right ends of the second guide rod 54 are respectively set on the left and right sides of the inner cavity of the slide groove 53. The slider 512 is slidably sleeved on the outer wall of the second guide rod 54. The first spring 55 is sleeved on the outer side of the outer wall of the second guide rod 54. One end of the first spring 55 is clamped on the inner wall of the slide groove 53, and the other end of the first spring 55 is clamped on the outer wall of the slider 512. The first spring 55 is a rotation spring. It undergoes elastic deformation when squeezed or stretched by external force and returns to its original state after the external force is removed. The first spring 55 is used to push the slider 512 to return to its original position.

[0033] As a preferred solution, further, the centering positioning mechanism 6 includes: a gear disc 61, a driving groove 62, a positioning plate 63, a telescopic groove 64, a limiting groove 65, a clamping plate 66, a driving column 67, a first guide rod 68, a screw 69 and a rack plate 610. There are two gear discs 61, and the two gear discs 61 are rotatably arranged on the front and rear sides of the current transformer 1 through bearings. The front side of the gear disc 61 is provided with a plurality of driving grooves 62 that pass through the front and rear at equal distances along the circumference. The positioning plate 63 is sleeved on the outer wall of the current transformer 1. The gear disc 61 is located in the inner cavity of the positioning plate 63. The outer wall of the positioning plate 63 is provided with a plurality of telescopic grooves 64 that are connected to its inner cavity at equal distances along the circumference on both sides. The inner cavity of the positioning plate 63 is provided with a plurality of limiting grooves 65 that are connected to the inner cavity of the telescopic groove 64 at equal distances along the circumference on both sides. The positions of the plurality of limiting grooves 65 correspond one to one to the positions of the plurality of driving grooves 62. The holding plate 66 is slidably embedded in the inner cavity of the telescopic groove 64, and the clamping plate 66 is used to clamp and fix the live wire at the center of the magnetic core hole 2. The driving column 67 is arranged at the inner outer end of the clamping plate 66, and the outer wall of the driving column 67 can slidably pass through the outer side of the inner cavity of the limit groove 65 and can slidably extend into the outer side of the inner cavity of the driving groove 62. When the gear plate 61 rotates, the cooperation between the driving groove 62 and the telescopic groove 64 can prompt the driving column 67 to drive the clamping plate 66 to move inward. There are two first guide rods 68, and the two first guide rods 68 are respectively arranged at the front and rear ends of the top right side of the current transformer 1. The bottom end of the screw 69 is rotatably arranged at the middle part of the top right side of the current transformer 1 through a bearing. The rack plate 610 is slidably sleeved on the top end of the outer wall of the first guide rod 68, and the rack plate 610 is screwed to the outer wall of the screw 69. The rack plate 610 and the two gear plates 61 are meshed.

[0034] A method for using a nanocrystalline current transformer capable of resisting direct current components comprises the following steps:

[0035] Step 1. When in use, electrically connect the positive pole of the external instrument to the first terminal 4, and electrically connect the negative pole of the external instrument to the positive pole of one of the power-off electromagnets 518, insert the wire into the inner cavity of the magnetic core hole 2, rotate the screw 69, and the rotational force generated by the rotation of the screw 69 prompts the rack plate 610 to slide downward along the outer wall of the first guide rod 68. The downward movement of the rack plate 610 prompts the two gear plates 61 to rotate clockwise. The clockwise rotation of the gear plate 61 utilizes the cooperation between the driving groove 62 and the limiting groove 65 to prompt the driving column 67 to drive the clamping plate 66 to move inward until the clamping plate 66 is used to clamp and fix the wire. At this time, the wire is located at the center point of the magnetic core hole 2, thereby ensuring that the magnetic field generated by the wire can pass through the current transformer 1 more evenly, reducing the leakage magnetic phenomenon caused by the deviation of the wire position from the center, and connecting the wire to the power supply, you can use the external instrument to measure the current;

[0036] Step 2: As the current transformer 1 is used, if an open circuit occurs on the secondary side due to loose terminals, broken secondary cables, poor contact of relays or contactors, etc., the circuit between the second terminal 3 and the first terminal 4 will be disconnected, thereby causing the two de-energized electromagnets 518 to lose power and restore their magnetic force. As a result, the two de-energized electromagnets 518 and the two permanent magnets 526 will repel each other and push the insulating block 516 to move the conductive sheet 515 upward, stretching the second spring 517 to cause elastic deformation until the conductive sheet 515 is released. 515 contacts both the first contact 519 and the second contact 520, thereby restoring the circuit between the first terminal 4 and the second terminal 3, causing the warning light 522 to emit light, the speaker 523 to emit sound, and transmitting a signal to the main control center to remind the staff to perform maintenance, thereby preventing the secondary side of the current transformer 1 from being open-circuited and eliminating safety hazards. After the maintenance is completed, the external instrument resumes operation, thereby prompting the power supply of the power-off type electromagnet 518 to resume. The magnetic force of the power-off type electromagnet 518 disappears, and the elastic force of the second spring 517 pulls the insulating block 516 to drive the conductive piece 515 to return to its initial position;

[0037] When the cam 512 is in the open position, the first spring 55 is pressed against the first contact 519 and the second contact 520 is pressed against the first contact 520. When the cam 512 is in the open position, the first spring 55 is pressed against the first contact 519 and the second contact 520 is pressed against the first contact 519 and the second contact 520. When the cam 512 is in the open position, the first spring 55 is pressed against the first contact 519 and the second contact 520 is pressed against the first contact 519 and the second contact 520. When the cam 512 is in the open position, the first spring 55 is pressed against the first contact 519 and the second contact 520 is pressed against the first contact 519 and the second contact 520.

[0038] In summary, the device is provided with a secondary side circuit breaker detection and protection mechanism, which effectively prevents the imbalance of the internal magnetic field of the transformer caused by the disconnection of the secondary circuit, avoids the saturation of the core magnetic flux and the generation of potential high electromotive force, thereby protecting the safety of the transformer itself and peripheral equipment, and reducing the risk of power system failures such as fire or short circuit. At the same time, a live wire centering fixing mechanism is provided to ensure the stable center position of the wire in the transformer core hole 2, optimize the magnetic field distribution, reduce the leakage magnetic phenomenon, significantly improve the accuracy and stability of current measurement, and at the same time reduce the measurement fluctuation introduced by the wire shaking, providing more accurate data support for harmonic analysis, fault detection and power quality monitoring of the power system.

[0039] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A nanocrystalline current transformer with DC resistance, characterized in that: include: A current transformer (1), wherein a magnetic core hole (2) is provided in the middle of the front side of the current transformer (1) and extends through the front and back; A second wiring terminal (3), the second wiring terminal (3) being arranged on the left side of the bottom end of the front side of the current transformer (1); A first wiring terminal (4), the first wiring terminal (4) being arranged on the right side of the bottom end of the front side of the current transformer (1); A monitoring and protection mechanism (5), the monitoring and protection mechanism (5) being arranged at the middle of the front bottom end of the current transformer (1); A centering positioning mechanism (6), the centering positioning mechanism (6) being arranged on the front side of the current transformer (1); The monitoring and protection mechanism (5) includes: A connecting piece (525), wherein the number of the connecting pieces (525) is two, and the two connecting pieces (525) are respectively arranged on the outer walls of the first connecting terminal (4) and the second connecting terminal (3), and the connecting piece (525) is electrically connected to the first connecting terminal (4) and the second connecting terminal (3); a second conductive wire (524), one end of the second conductive wire (524) being disposed on the inner side of the connecting piece (525), and the second conductive wire (524) and the connecting piece (525) being electrically connected; A speaker (523), wherein the positive electrode of the speaker (523) is electrically connected to the other end of the second wire (524) located on the right side; A warning light (522), wherein the negative electrode of the warning light (522) is electrically connected to the other end of the second wire (524) located on the left side; A first wire (521), wherein the number of the first wires (521) is two, one end of one of the first wires (521) is electrically connected to the negative pole of the speaker (523), and the other end of the first wire (521) is electrically connected to the positive pole of the warning light (522); a second contact (520), the second contact (520) being arranged at the other end of the first wire (521) located on the right side; a first contact (519), the first contact (519) being arranged at the other end of the first wire (521) located on the left side; The centering positioning mechanism (6) comprises: Gear plates (61), the number of the gear plates (61) is two, and the two gear plates (61) are rotatably arranged on the front and rear sides of the current transformer (1) through bearings, and the front side of the gear plate (61) is provided with a plurality of driving grooves (62) extending through the front and rear at equal intervals along the circumferential direction; A positioning plate (63), the positioning plate (63) being sleeved on the outer wall of the current transformer (1), the gear plate (61) being located in the inner cavity of the positioning plate (63), a plurality of telescopic slots (64) being equidistantly provided on both the front and rear sides of the outer wall of the positioning plate (63) along the circumferential direction and communicating with the inner cavity of the positioning plate (63), a plurality of limiting slots (65) being equidistantly provided on both the front and rear sides of the inner cavity of the positioning plate (63) along the circumferential direction and communicating with the inner cavity of the telescopic slots (64), the positions of the plurality of limiting slots (65) corresponding to the positions of the plurality of driving slots (62); A clamping plate (66), wherein the clamping plate (66) is slidably embedded in the inner cavity of the telescopic slot (64); A driving column (67) is provided at the inner outer end of the clamping plate (66), and the outer wall of the driving column (67) can slide through the outer side of the inner cavity of the limiting groove (65) and can slide to extend into the outer side of the inner cavity of the driving groove (62).

2. The nanocrystalline current transformer with DC component resistance according to claim 1, characterized in that: The monitoring and protection mechanism (5) further comprises: A protection box (51), the protection box (51) being arranged at the middle of the bottom end of the front side of the current transformer (1), the middle of the front side of the protection box (51) being provided with a movable groove (52) communicating with the inner cavity thereof in the vertical direction, and both left and right ends of the middle of the inner cavity of the protection box (51) being provided with sliding grooves (53) in the horizontal direction; a second support plate (513), the second support plate (513) being arranged at the middle of the top end of the front side of the inner cavity of the protection box (51), and the first contact (519) and the second contact (520) being arranged at the bottom end of the second support plate (513); A fourth guide rod (514), the number of the fourth guide rods (514) is two, the top ends of the two fourth guide rods (514) are respectively arranged at the front and rear sides of the middle of the bottom end of the second support plate (513), and the bottom ends of the two fourth guide rods (514) are both arranged at the bottom end of the inner cavity of the protection box (51); an insulating block (516), the insulating block (516) being slidably sleeved on the middle portion of the outer wall of the fourth guide rod (514); A conductive sheet (515), the conductive sheet (515) being arranged on the top end of the insulating block (516), and the conductive sheet (515) being slidably sleeved on the outer wall of the fourth guide rod (514); The second spring (517) is sleeved on the bottom end of the outer wall of the fourth guide rod (514), the top end of the second spring (517) is clamped on the bottom end of the insulating block (516), and the bottom end of the second spring (517) is clamped on the bottom end of the inner cavity of the protection box (51).

3. The nanocrystalline current transformer with DC component resistance according to claim 2, characterized in that: The monitoring and protection mechanism (5) further comprises: Permanent magnets (526), ​​the number of the permanent magnets (526) is two, and the two permanent magnets (526) are respectively arranged on the left and right sides of the bottom end of the insulating block (516); A de-energized electromagnet (518), wherein the number of the de-energized electromagnet (518) is two, and the two de-energized electromagnets (518) are respectively arranged at the left and right ends of the middle of the front side of the inner cavity of the protection box (51), and the top ends of the two de-energized electromagnets (518) are respectively in contact with the bottom ends of the two permanent magnets (526), ​​and the de-energized electromagnet (518) and the permanent magnets (526) are of the same polarity and repel each other, and the positive pole of one de-energized electromagnet (518) is electrically connected to the negative pole of the other de-energized electromagnet (518), and the negative pole of the de-energized electromagnet (518) is electrically connected to the second terminal (3).

4. The nanocrystalline current transformer with DC component resistance according to claim 3, characterized in that: The monitoring and protection mechanism (5) further comprises: A first support plate (56), the number of the first support plates (56) being two, and the two first support plates (56) being respectively arranged at the upper and lower ends of the middle portion of the front side of the inner cavity of the protection box (51); A third guide rod (57), wherein the number of the third guide rods (57) is two, and the upper and lower ends of the two third guide rods (57) are respectively arranged at the left and right ends of the inner sides of the two first support plates (56); A moving block (58), wherein the moving block (58) is slidably sleeved on the bottom end of the outer wall of the third guide rod (57); A sliding post (59), the sliding post (59) is arranged at the middle of the front side of the moving block (58), and the front end of the sliding post (59) can slidably extend out of the bottom end of the inner cavity of the moving groove (52); A push rod (510), the push rod (510) being arranged on the rear side of the moving block (58), the top end of the push rod (510) being in contact with the bottom end of the insulating block (516); Connecting rods (511), the number of the connecting rods (511) is two, and one end of the two connecting rods (511) is rotatably arranged on the left and right sides of the moving block (58) through a pin shaft; A slider (512), the slider (512) is rotatably arranged at the other end of the connecting rod (511) via a pin, and the two sliders (512) are respectively slidably adapted to be inserted into the inner sides of the inner cavities of the two slide grooves (53); A second guide rod (54), wherein the left and right ends of the second guide rod (54) are respectively arranged on the left and right sides of the inner cavity of the slide groove (53), and the slider (512) is slidably sleeved on the outer wall of the second guide rod (54); A first spring (55) is sleeved on the outer side of the outer wall of the second guide rod (54), one end of the first spring (55) is clamped on the inner wall of the sliding groove (53), and the other end of the first spring (55) is clamped on the outer wall of the slider (512).

5. The nanocrystalline current transformer with DC component resistance according to claim 4, characterized in that: The centering positioning mechanism (6) further comprises: A first guide rod (68), wherein the number of the first guide rods (68) is two, and the two first guide rods (68) are respectively arranged at the front and rear ends of the right side of the top of the current transformer (1); A screw rod (69), the bottom end of the screw rod (69) is rotatably arranged at the middle right side of the top end of the current transformer (1) via a bearing; The rack plate (610) is slidably sleeved on the top of the outer wall of the first guide rod (68), the rack plate (610) is screwed to the outer wall of the screw rod (69), and the rack plate (610) and the two gear plates (61) are meshed.

6. The nanocrystalline current transformer with DC component resistance according to claim 5, characterized in that: The distance between the upper and lower ends of the inner cavity of the movable slot (52) is greater than the distance from the top of the conductive sheet (515) to the bottom ends of the first contact (519) and the second contact (520).

7. The method for using a nanocrystalline current transformer with DC component resistance according to claim 6, characterized in that: The following steps are involved: Step 1: When in use, electrically connect the positive pole of the external instrument to the first terminal (4), and electrically connect the negative pole of the external instrument to the positive pole of one of the power-off electromagnets (518), insert the wire into the inner cavity of the magnetic core hole (2), rotate the screw (69), and the rotational force generated by the rotation of the screw (69) causes the rack plate (610) to slide downward along the outer wall of the first guide rod (68). The downward movement of the rack plate (610) causes the two gear plates (61) to rotate clockwise, and the gears The disk (61) rotates clockwise, and the driving slot (62) and the limiting slot (65) cooperate to cause the driving column (67) to drive the clamping plate (66) to move inward, until the wire is clamped and fixed by the clamping plate (66). At this time, the wire is located at the center point of the magnetic core hole (2), thereby ensuring that the magnetic field generated by the wire can pass through the current transformer (1) more evenly, reducing the leakage magnetic field caused by the deviation of the wire position from the center, and connecting the wire to the power supply to realize the current measurement using the external instrument; Step 2: As the current transformer (1) is used, if an open circuit occurs on the secondary side due to loose terminals, broken secondary cables, poor contact of relays or contactors, etc., the circuit between the second terminal (3) and the first terminal (4) will be disconnected, thereby causing the two de-energized electromagnets (518) to lose power, causing the two de-energized electromagnets (518) to restore magnetic force, thereby pushing the insulating block (516) to drive the conductive sheet (515) to move upward under the action of the repulsion between the two de-energized electromagnets (518) and the two permanent magnets (526), ​​and stretching the second spring (517) to undergo elastic deformation until the conductive sheet (515) is retracted. 5) contacting both the first contact (519) and the second contact (520), thereby prompting the first terminal (4) and the second terminal (3) to resume conduction, prompting the warning light (522) to emit light, the speaker (523) to emit sound, and transmitting the signal to the main control center to remind the staff to perform maintenance, thereby preventing the secondary side of the current transformer (1) from being open-circuited and eliminating safety hazards. After the maintenance is completed, the external instrument resumes work, thereby prompting the power-off type electromagnet (518) to resume power supply, the magnetic force of the power-off type electromagnet (518) disappears, and under the elastic force of the second spring (517), the insulating block (516) can be pulled to drive the conductive sheet (515) to return to its initial position; Step 3: When the external instrument needs to be repaired or maintained, the sliding column (59) is slid upward, and the sliding column (59) slides upward to drive the moving block (58) to move upward. The moving block (58) moves upward and drives the insulating block (516) to move upward through the push rod (510), and then uses the insulating block (516) to drive the conductive sheet (515) to move upward. The moving block (58) moves upward and uses the connecting rod (511) to push the slider (512) to move outward along the inner cavity of the slide groove (53), and squeezes the first spring (55) to cause elastic deformation. Until the connecting rod (511) and the slide groove (53) are at the same horizontal plane, at this time, the sliding column (59) continues to slide upward to drive the moving block (58) to move upward, which can prompt the first spring (55) to push the slider (512) to move inward along the inner cavity of the slide groove (53) until the slider (512) returns to the initial position, prompting the conductive sheet (515) to contact the first contact (519) and the second contact (520). At this time, the external instrument can be disassembled for repair and maintenance, thereby preventing the secondary side of the current transformer (1) from being open-circuited.

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