Nanocrystalline current transformer resistant to direct-current component and using method of nanocrystalline current transformer resistant to direct-current component

Abstract

The invention discloses an anti-direct-current component nanocrystalline current transformer and a using method thereof. The anti-direct-current component nanocrystalline current transformer comprises a current transformer body, and a magnetic core hole penetrating front and back is formed in the middle of the front side of the current transformer body. The device is provided with a secondary side open circuit detection and protection mechanism, so that imbalance of a magnetic field in the mutual inductor caused by disconnection of a secondary loop is effectively prevented, iron core magnetic flux saturation and potential high electromotive force generation are avoided, the safety of the mutual inductor and peripheral equipment is protected, the risk of power system faults such as fire disasters or short circuits is reduced, and meanwhile, the safety of the mutual inductor is improved. A live wire centering fixing mechanism is arranged, so that the stable centering position of a wire in a magnetic core hole of the mutual inductor is ensured, magnetic field distribution is optimized, the magnetic leakage phenomenon is reduced, the accuracy and stability of current measurement are remarkably improved, meanwhile, measurement fluctuation caused by wire shaking is reduced, and the measurement precision is improved. And more accurate data support is provided for harmonic analysis, fault detection and electric energy quality monitoring of a 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 the power system, the current transformer is a key measurement and protection device that is responsible for converting large current into small current in proportion for use by 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 intensity, low loss and good temperature stability. In particular, nanocrystalline current transformers that are resistant to DC components have become the preferred solution in the power system due to their unique advantages in suppressing DC component interference and improving measurement accuracy. As the name implies, the core of the DC-resistant nanocrystalline current transformer is to use the special magnetic properties of nanocrystalline alloy materials to effectively filter out the DC component in the current signal, thereby ensuring the accuracy and stability of the measurement results. This characteristic is of great significance for harmonic analysis, fault detection and power quality monitoring in power systems. However, although the DC-resistant nanocrystalline current transformer has made significant technical progress, it still faces technical problems that need to be solved in practical applications. First, the importance of secondary side circuit break detection and protection mechanism is often ignored in the design of traditional DC-resistant nanocrystalline current transformers. When the current transformer is working normally, its secondary side must remain closed to ensure the correct conversion and transmission of current. Once the secondary side is open due to loose terminals, broken secondary cables, poor contact of relays or contactors, etc., that is, the secondary circuit is disconnected, it will directly lead to an imbalance of the internal magnetic field of the transformer, and the primary current will almost entirely be converted into excitation current, which will cause serious saturation of the core flux. In this state, extremely high electromotive force may be generated at both ends of the transformer, which may not only damage the transformer itself, but also pose a serious threat to the safety of surrounding equipment and even operators. In addition, excessive saturation of the core will significantly increase its loss, causing severe heating of the core, with the risk of burning the transformer or breaking down the insulation of the secondary winding, which will lead to more extensive power system failures, such as fire or short circuit accidents. Especially if it is not properly handled for a long time, the transformer shell may melt due to high temperature, exposing the core, further exacerbating the danger of the accident. 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 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, leading to an increase in magnetic leakage. The increase in magnetic leakage means that the transformer's ability to capture current changes in the conductor decreases, and the measurement accuracy decreases 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

[0003] The object of the present invention is to provide a nanocrystalline current transformer with DC resistance and a method of using the same, so as to at least solve the problem in the prior art that there are potential safety hazards and the position of the conductor cannot be fixed.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a nanocrystalline current transformer with DC component resistance, comprising: a current transformer, a magnetic core hole penetrating front and back is opened 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.

[0005] Preferably, the monitoring and protection mechanism includes: a connecting plate, two connecting plates are respectively arranged on the outer walls of the first terminal and the second terminal, and the connecting plate 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 plate, and the second wire and the connecting plate are electrically connected; the positive pole of the speaker is electrically connected to the other end of the second wire located on the right; the negative pole of the warning light is electrically connected to the other end of the second wire located on the left; there are two first wires, one end of one of the first wires 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 located on the right; the first contact is arranged at the other end of the first wire located on the left.

[0006] Preferably, in order to promote the conduction of the circuit of the first wiring terminal and the second wiring terminal, the monitoring and protection mechanism also includes: a protection box, the protection box is arranged in the middle of the front bottom end of the current transformer, the front middle end of the protection box is provided with a movable groove connected to its inner cavity in the up and down direction, and the left and right ends of the middle of the front inner cavity of the protection box are provided with sliding grooves in the left and right directions; the second support plate is arranged in the middle of the front top 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 rear 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 sleeved on 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 sleeved on the outer wall of the fourth guide rod; the second spring is sleeved on the bottom end of the outer wall of the fourth guide rod, the top end of the second spring is clamped on the bottom end of the insulating block, and the bottom end of the second spring is clamped on the bottom end of the inner cavity of the protection box.

[0007] Preferably, in order to drive the insulating block to move, the monitoring and protection mechanism also includes: a permanent magnet, two permanent magnets, which are respectively arranged on the left and right sides of the bottom end of the insulating block; a de-energizing electromagnet, two de-energizing electromagnets, which 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 tops of the two de-energizing electromagnets are respectively in contact with the bottoms of the two permanent magnets, the de-energizing electromagnets and the permanent magnets repel each other with like poles, the positive pole of one de-energizing electromagnet is electrically connected to the negative pole of the other de-energizing electromagnet, and the negative pole of the de-energizing electromagnet is electrically connected to the second terminal.

[0008] 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 part 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 and The bottom ends of the insulating blocks are in contact with each other; there are two connecting rods, one end of the two connecting rods is rotatably arranged on the left and right sides of the moving block through a pin shaft; the slider is rotatably arranged 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 arranged on the left and right sides of the inner cavity of the slide groove, and the slider is slidably sleeved on the outer wall of the second guide rod; the first spring is sleeved on the outer side of the outer wall of the second guide rod, one end of the first spring is clamped on the inner wall of the slide groove, and the other end of the first spring is clamped on the outer wall of the slider.

[0009] Preferably, in order to clamp and position the live wire in the center, the center positioning mechanism includes: a gear plate, two gear plates, which are rotatably arranged on the front and rear sides of the current transformer through bearings, and a plurality of drive grooves penetrating front and rear are opened at equal distances along the circumferential direction on the front side of the gear plate; 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 a plurality of telescopic grooves connected to the inner cavity are opened at equal distances along the circumferential direction on the front and rear sides of the outer wall of the positioning plate, and a plurality of limit grooves connected to the inner cavity of the telescopic groove are opened at equal distances along the circumferential direction on the front and rear sides of the inner cavity of the positioning plate, and the positions of the plurality of limit grooves correspond to the positions of the plurality of drive grooves one by one; the clamping plate can be slidably embedded in the inner cavity of the telescopic groove; the driving column is arranged at the inner outer end of the clamping plate, and the outer wall of the driving column can slidably penetrate 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.

[0010] 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.

[0011] 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.

[0012] The invention provides a nanocrystalline current transformer with DC resistance and a method for using the same, which has the following beneficial effects: 1. The present invention utilizes a current transformer to convert a large current into a small current in proportion, and drives the rack plate to move downward by rotating a screw, and then the rack plate can be used to drive the gear plate to rotate clockwise, so that 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 then the clamping plate can be used to fix the live wire at 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.

[0013] 2. The present invention can prevent the first wiring terminal and the second wiring terminal from being open-circuited by causing the conductive sheet to contact the first contact and the second contact. The insulating block can drive the conductive sheet to move upward by utilizing the principle of like-charged repulsion between a de-energized electromagnet and a permanent magnet or by causing the upward sliding moving block to drive the push rod to move upward, thereby causing the conductive sheet to contact the first contact and the second contact.

[0014] 3. The device is equipped 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 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 core hole of the transformer, optimize the magnetic field distribution, reduce the leakage magnetic phenomenon, significantly improve the accuracy and stability of current measurement, and reduce the measurement fluctuations introduced by the wire shaking, providing more accurate data support for harmonic analysis, fault detection and power quality monitoring of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 An exploded view of the present invention; Figure 3 It is a schematic diagram of the structure of the inner cavity of the protection box; Figure 4 Explosion diagram for monitoring protection agencies; Figure 5 It is a structural schematic diagram of a permanent magnet; Figure 6 for Figure 2 A magnified image of point A; Figure 7 for Figure 2 A magnified view of point B; Figure 8 for Figure 4 Enlarged view of point C; Fig. 9 for Figure 5 The enlarged view of point D; Fig.10 for Figure 5 Enlarged view of point E.

[0016] In the figure: 1, current transformer; 2, magnetic core hole; 3, second terminal; 4, first terminal; 5, monitoring 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 type 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

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0018] 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 herein. The current transformer 1 is used to convert a large current into a small current. The second terminal 3 is arranged at the left side of the bottom end of the front side of the current transformer 1, and the first terminal 4 is arranged at the right side of the bottom end of the front side of the current transformer 1. The monitoring and protection mechanism 5 is arranged at 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 at 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.

[0019] As a preferred solution, further, the monitoring and protection mechanism 5 includes: a protection box 51, a moving groove 52, a sliding groove 53, a second guide rod 54, a first spring 55, a first support plate 56, a third guide rod 57, a moving block 58, a sliding 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 sheet 525 and a permanent magnet 526, the number of the connecting sheets 525 is two, and the two connecting sheets 525 are respectively arranged on the first terminal 4 and the second terminal 3, the connecting piece 525 is electrically connected to the first wiring terminal 4 and the second wiring 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 located on the right side, the speaker 523 is a prior art, 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 located on the left side, the warning light 522 is a prior art, 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, 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 arranged at the other end of the first wire 521 located on the right, the first contact 519 is arranged at the other end of the first wire 521 located on the left, the protection box 51 is arranged at the middle of the front bottom end of the current transformer 1, the front middle part of the protection box 51 is provided with a movable groove 52 connected to its inner cavity along the up-down direction, the left and right ends of the front middle part of the inner cavity of the protection box 51 are both provided with sliding grooves 53 along the left-right direction, 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 first contact 519 and the bottom of 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 of the second support plate 513. There are two fourth guide rods 514. The tops of the two fourth guide rods 514 are respectively arranged at the front and rear sides of the middle of the bottom of the second support plate 513. The bottoms of the two fourth guide rods 514 are both arranged at the bottom of the inner cavity of the protection box 51. The insulating block 516 is slidably sleeved on 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 sleeved on the outer wall of the fourth guide rod 514. When the conductive sheet 515 contacts the first contact 519 and the second contact 520,The circuit of the first terminal 4 and the second terminal 3 can be connected. 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 protection box 51. The second spring 517 is a rotation 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 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 type electromagnets 518 is two, and the two power-off type electromagnets 518 are respectively It is arranged at the left and right ends of the middle part of the front side of the inner cavity of the protection box 51, and the tops of the two de-energized electromagnets 518 are in contact with the bottom ends of the two permanent magnets 526 respectively. The de-energized electromagnets 518 and the permanent magnets 526 are like-charged and repel each other. 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. The de-energized electromagnet 518 is a prior art. After the de-energized electromagnet 518 is energized, the magnetism disappears, and after the power is cut off, the magnetism is restored. The de-energized 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 de-energized 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, 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, the moving block 58 can be 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 part of the front side of the moving block 58, and 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 is in contact with the bottom end of the insulating block 516, and 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 the pin shaft. On the left and right sides of the movable block 58, the slider 512 is rotatably arranged at the other end of the connecting rod 511 through a pin shaft, and the two sliders 512 are respectively slidably adapted and inserted into the inner side of the inner cavity of the two slide grooves 53. 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. The slider 512 is slidably sleeved on the outer wall of the second guide rod 54, and 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, which undergoes elastic deformation after being squeezed or stretched by external force, and returns to its initial state after the external force is removed. The first spring 55 is used here to push the slider 512 to return to its initial position.

[0020] As a preferred embodiment, further, the centering positioning mechanism 6 includes: a gear plate 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 plates 61, and the two gear plates 61 are rotatably arranged on the front and rear sides of the current transformer 1 through bearings. The front side of the gear plate 61 is provided with a plurality of driving grooves 62 that penetrate the front and rear at equal intervals along the circumferential direction. The positioning plate 63 is sleeved on the outer wall of the current transformer 1. The gear plate 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 intervals along the circumferential direction on both sides of the front and rear of the outer wall. 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 intervals along the circumferential direction on both sides of the front and rear. The positions of the plurality of limiting grooves 65 correspond to the positions of the plurality of driving grooves 62 one by one. The holding plate 66 can be 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. The outer wall of the driving column 67 can slidably penetrate the outer side of the inner cavity of the limiting 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 driving groove 62 and the telescopic groove 64 can be used 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 can be slidably sleeved on the top 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, and the rack plate 610 and the two gear plates 61 are meshed.

[0021] A method for using a nanocrystalline current transformer capable of resisting direct current components comprises the following steps: 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 type 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 will prompt 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 can 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, causing the two de-energized electromagnets 518 to lose power and restore magnetic force. As a result, the insulating block 516 can be pushed 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 the second spring 517 can be stretched to elastically deform until the conductive sheet 515 is pushed upward. 515 contacts both the first contact 519 and the second contact 520, thereby prompting the circuit of the first wiring terminal 4 and the second wiring 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 carry out 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, and the magnetic force of the power-off type electromagnet 518 disappears. 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 the initial position; The movable block 58 moves upward and drives the insulating block 516 to move upward through the push rod 510, and then drives the conductive sheet 515 to move upward by using the insulating block 516. The movable block 58 moves upward and drives the slider 512 to move outward along the inner cavity of the slide groove 53 by using the connecting rod 511, and squeezes the first spring 55 to elastically deform until the connecting rod 511 and the slide groove 53 are in the same horizontal plane. At this time, the movable block 59 continues to slide upward to drive the movable block 58 to move upward, so that the first spring 55 can push the slider 512 to move inward along the inner cavity of the slide groove 53 until the slider 512 returns to its initial position, and drives the conductive sheet 515 to contact with the first contact 519 and the second contact 520. At this time, the external instrument can be disassembled for maintenance, thereby preventing the secondary side of the current transformer 1 from being open circuited.

[0022] In summary, the device is provided 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 flux saturation and the 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 reduce the measurement fluctuation introduced by the wire shaking, which provides more accurate data support for harmonic analysis, fault detection and power quality monitoring of the power system.

[0023] Although 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 the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present 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) penetrating front to back is provided in the middle of the front side of the current transformer (1); 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), wherein the monitoring and protection mechanism (5) is arranged at the middle of the bottom end of the front side of the current transformer (1); A centering positioning mechanism (6), wherein the centering positioning mechanism (6) is arranged on the front side of the current transformer (1); The monitoring and protection mechanism (5) comprises: A connecting piece (525), the number of the connecting pieces (525) being two, the two connecting pieces (525) being respectively arranged on the outer walls of the first connecting terminal (4) and the second connecting terminal (3), and the connecting piece (525) being electrically connected to both 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 arranged 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 a positive electrode of the speaker (523) is electrically connected to the other end of a second wire (524) located on the right side; A warning light (522), wherein a negative electrode of the warning light (522) is electrically connected to the other end of a second wire (524) located on the left side; A first wire (521), the number of the first wires (521) being two, one end of one of the first wires (521) being electrically connected to the negative pole of the speaker (523), and one end of the other first wire (521) being 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 conductive wire (521) located on the right side; A first contact (519), wherein the first contact (519) is arranged at the other end of the first wire (521) located on the left side.

2. A 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) in the up-down direction and communicating with the inner cavity thereof, and the left and right ends of the middle of the front side of the inner cavity of the protection box (51) being provided with sliding grooves (53) in the left-right 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 point (519) and the second contact point (520) being arranged at the bottom end of the second support plate (513); A fourth guide rod (514), wherein 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 a middle portion of an 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); A second spring (517), wherein 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. A 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) being two, and the two permanent magnets (526) being 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, the two de-energized electromagnets (518) being 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 top ends of the two de-energized electromagnets (518) respectively contact the bottom ends of the two permanent magnets (526), ​​the de-energized electromagnets (518) and the permanent magnets (526) are of the same polarity and repel each other, the positive pole of one of the de-energized electromagnets (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 wiring terminal (3).

4. A 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 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 column (59), wherein the sliding column (59) is arranged at the middle portion of the front side of the moving block (58), and 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); 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) being two, and one end of the two connecting rods (511) being rotatably disposed on the left and right sides of the moving block (58) via pins; A slider (512), the slider (512) being rotatably disposed at the other end of the connecting rod (511) via a pin shaft, and the two sliders (512) being slidably adapted to be inserted into the inner sides of the inner cavities of the two slide grooves (53); A second guide rod (54), 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 sliding block (512) is slidably sleeved on the outer wall of the second guide rod (54); A first spring (55), wherein 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 slide block (512).

5. The nanocrystalline current transformer with DC component resistance according to claim 4, characterized in that: The centering positioning mechanism (6) comprises: Gear plates (61), the number of the gear plates (61) being two, the two gear plates (61) being rotatably arranged on the front and rear sides of the current transformer (1) via bearings, and the front side of the gear plates (61) being provided with a plurality of drive grooves (62) penetrating the front and rear sides at equal intervals in 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 grooves (64) being equidistantly provided along the circumferential direction on both the front and rear sides of the outer wall of the positioning plate (63) and being communicated with the inner cavity thereof, a plurality of limiting grooves (65) being equidistantly provided along the circumferential direction on both the front and rear sides of the inner cavity of the positioning plate (63) and being communicated with the inner cavity of the telescopic grooves (64), the positions of the plurality of limiting grooves (65) corresponding to the positions of the plurality of driving grooves (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), wherein 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 penetrate the outer side of the inner cavity of the limiting groove (65), and can slidably extend into the outer side of the inner cavity of the driving groove (62).

6. A nanocrystalline current transformer with DC component resistance according to claim 5, characterized in that: The centering positioning mechanism (6) further comprises: A first guide rod (68), the number of the first guide rods (68) being two, and the two first guide rods (68) being respectively arranged at the front and rear ends of the right side of the top end of the current transformer (1); A screw rod (69), the bottom end of the screw rod (69) being rotatably arranged at the middle part of the 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 with each other.

7. A nanocrystalline current transformer with DC component resistance according to claim 6, 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 of the first contact point (519) and the second contact point (520).

8. The method for using a nanocrystalline current transformer capable of resisting direct current components according to claim 7, characterized in that: The following steps are involved: Step 1: When in use, the positive pole of the external instrument is electrically connected to the first terminal (4), and the negative pole of the external instrument is electrically connected to the positive pole of one of the power-off type electromagnets (518), and the wire is inserted into the inner cavity of the magnetic core hole (2), and the screw rod (69) is rotated. The rotational force generated by the rotation of the screw rod (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 magnetic leakage phenomenon caused by the deviation of the wire position from the center, and connecting the wire to the power supply to realize current measurement using an 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 relay or contactor contacts, 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 magnetic force. As a result, the insulating block (516) can be pushed to drive the conductive sheet (515) to move upward under the action of repulsion between the two de-energized electromagnets (518) and the two permanent magnets (526), ​​and the second spring (517) can be stretched to undergo elastic deformation until the conductive sheet (515) is moved upward. 5) contacting both the first contact point (519) and the second contact point (520), thereby causing the circuits of the first wiring terminal (4) and the second wiring terminal (3) to resume conduction, causing the warning light (522) to emit light, the speaker (523) to emit a sound, and transmitting a signal to the main control center to remind the staff to carry out 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 causing the power-off type electromagnet (518) to resume power supply, the magnetic force of the power-off type electromagnet (518) disappears, and the elastic force of the second spring (517) can pull the insulating block (516) 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 slide column (59) is slid upward. The slide column (59) slides upward to drive the moving block (58) to move upward. The moving block (58) moves upward to drive the insulating block (516) to move upward through the push rod (510), and then the insulating block (516) drives the conductive sheet (515) to move upward. The moving block (58) moves upward to use the connecting rod (511) to push the slider (512) to move outward along the inner cavity of the slide groove (53), and squeeze the first spring (55) to cause elastic deformation. The connecting rod (511) and the slide groove (53) are moved to the same horizontal plane. At this time, the slide column (59) continues to slide upward to drive the moving block (58) to move upward, so that the first spring (55) can 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, so that the conductive sheet (515) contacts both 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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