CN117871926A - High-accuracy current measurement device for online detection - Google Patents
High-accuracy current measurement device for online detection Download PDFInfo
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- CN117871926A CN117871926A CN202410048741.0A CN202410048741A CN117871926A CN 117871926 A CN117871926 A CN 117871926A CN 202410048741 A CN202410048741 A CN 202410048741A CN 117871926 A CN117871926 A CN 117871926A
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- 238000005259 measurement Methods 0.000 title claims abstract description 19
- 238000001514 detection method Methods 0.000 title claims abstract description 16
- 238000004804 winding Methods 0.000 claims abstract description 77
- 239000000696 magnetic material Substances 0.000 claims description 11
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 6
- 229920005989 resin Polymers 0.000 claims description 6
- 239000011347 resin Substances 0.000 claims description 6
- 239000000463 material Substances 0.000 claims description 4
- 239000003822 epoxy resin Substances 0.000 claims description 3
- 238000002955 isolation Methods 0.000 claims description 3
- 229920000647 polyepoxide Polymers 0.000 claims description 3
- 230000001681 protective effect Effects 0.000 claims description 2
- 238000005538 encapsulation Methods 0.000 claims 1
- 238000000034 method Methods 0.000 abstract description 8
- 239000004020 conductor Substances 0.000 description 8
- 230000007246 mechanism Effects 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 238000012795 verification Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Abstract
The application relates to a high-accuracy current measurement device for online detection, which comprises a magnetic core, wherein the magnetic core is divided into four parts, namely a first partial magnetic core, a second partial magnetic core, a third partial magnetic core and a fourth partial magnetic core; the first partial magnetic core, the second partial magnetic core, the third partial magnetic core and the fourth partial magnetic core are sequentially connected end to form a complete ring, and the magnetic core further comprises a secondary winding and an outer shielding shell, wherein the secondary winding is divided into four sections, the four sections of secondary windings are wound on the four partial magnetic cores respectively, and the four sections of secondary windings are wound in the same direction. The primary current collection method can safely and accurately collect the primary current of the current transformer for the distribution network.
Description
Technical Field
The application belongs to the field of current measurement devices, and particularly relates to a high-accuracy current measurement device for online detection.
Background
The primary winding of the low-voltage current transformer is connected to the power system, and the secondary winding is connected to the electric energy meter, so that the current of the primary system can be accurately measured and the electric energy metering can be performed. The current transformer realizes the electrical isolation of the secondary equipment and the primary equipment, effectively prevents the influence of primary overvoltage on the secondary measurement and protection equipment, and avoids the influence of secondary side faults on a primary loop. The performance of the current transformer is good and bad, and the accuracy and reliability of the measurement of the power system are directly affected.
According to the calibration procedure of JJG1189 'measuring transformer', the calibration period of the electromagnetic current transformer must not exceed 10 years, and the full coverage calibration of the transformer needs to be carried out by using a calibrating device. Because the off-line verification is required to power off the user, the user is applied to production and living, and more manpower and material resources are required to be consumed, and the verification work of the low-voltage transformer is difficult to develop, the remote on-line detection device for the distribution network current transformer for metering is needed to realize effective operation management and supervision on the metering performance of the distribution network transformer on line. The metering performance of the distribution network transformer is detected online, and primary current and secondary current signals of the current transformer are required to be accurately acquired. The distribution network current transformer is generally arranged in a line through a primary conductor in a penetrating way, and a primary current signal of the distribution network current transformer is obtained, namely, a primary conductor flowing current signal of the distribution network current transformer is measured. If the primary current signal is required to be measured on line without power failure, the line cannot be disassembled, and the current signal can be measured on the primary conductor only by adopting a clamp-shaped or open-close type current measuring device.
Because the shape, the size and the spacing of the primary conductors are different, the primary conductors are different in position when passing through the current measuring device, so that the magnetic field distribution of the magnetic core of the current measuring device is uneven, secondary output data of the current measuring device is unstable and inaccurate, primary loop current cannot be accurately fed back to the measuring meter, and errors of a current transformer cannot be accurately distributed and measured. Meanwhile, as the integration degree of the power equipment is improved, the equipment distance is obviously reduced, various charged bodies around the current transformer to be tested are continuously increased, the electric field environment is obviously deteriorated, more electromagnetic interference exists in the test environment, and the transmission characteristics of the current measuring device are seriously reduced after the current measuring device is interfered.
Disclosure of Invention
An object of the embodiments of the present application is to provide a high-accuracy current measurement device for online detection, which can balance electromagnetic waves in a magnetic core, and secondary current is not affected by different positions of a primary through conductor; the transmission characteristics are stable after being disturbed.
In order to achieve the above purpose, the present application provides the following technical solutions:
the embodiment of the application provides a high-accuracy current measurement device for online detection, which comprises a magnetic core, wherein the magnetic core is divided into four parts, namely a first partial magnetic core, a second partial magnetic core, a third partial magnetic core and a fourth partial magnetic core; the first partial magnetic core, the second partial magnetic core, the third partial magnetic core and the fourth partial magnetic core are sequentially connected end to form a complete ring, a first air gap is formed at the joint of the first partial magnetic core and the second partial magnetic core, a second air gap is formed at the joint of the second partial magnetic core and the third partial magnetic core, a third air gap is formed at the joint of the third partial magnetic core and the fourth partial magnetic core, and a fourth air gap is formed at the joint of the fourth partial magnetic core and the first partial magnetic core;
the secondary winding is divided into four sections, the four sections of secondary windings are respectively wound on the four partial magnetic cores, and the four sections of secondary windings are wound in the same direction; and the tail end of the first section of secondary winding is connected with the tail end of the third section of secondary winding in series; the head end of the first section secondary winding, the head end of the second section secondary winding and the tail end of the fourth section secondary winding are connected in parallel to form a secondary outlet end, and the head end of the third section secondary winding, the tail end of the second section secondary winding and the head end of the fourth section secondary winding are connected in parallel to form another secondary outlet end.
The lengths of the first partial magnetic core and the third partial magnetic core are 1/6 of the whole magnetic core; the lengths of the second partial magnetic core and the fourth partial magnetic core are 1/3 of the whole magnetic core.
The shielding windings are arranged in two pairs, and one pair of shielding windings is wound on the first partial magnetic core and the third partial magnetic core; the other pair of shielding windings are wound on the second partial magnetic core and the fourth partial magnetic core, and the winding directions inside each pair of shielding windings are opposite and the number of turns is the same.
The electromagnetic shielding layer is poured on the magnetic core and used for isolating the magnetic core, the secondary winding and the shielding winding; the electromagnetic shielding layer is divided into two layers and is respectively arranged between the isolation magnetic core and the secondary winding and between the secondary winding and the shielding winding; the material of the electromagnetic shielding layer may be an insulating resin.
The shielding shell comprises an outer shell and an inner shielding layer, and the cross section of the inner shielding layer is rectangular.
The insulating resin is coagulated between the magnetic core and the secondary winding outer shielding shell, and the insulating gel layer is modified, poured and packaged at 150-180 ℃ by adopting epoxy resin.
The soft magnetic material is distributed at the end part of the local iron core in a ring-shaped mode, the end part of the soft magnetic material is flush with the end part of the local iron core, and the thickness of the soft magnetic material is smaller than the radius of the coil.
The outer shielding shell is divided into a left half shell and a right half shell, the left half shell and the right half shell are semi-annular, one ends of the left half shell and the right half shell are hinged, and the other ends of the left half shell and the right half shell are connected through a locking block.
Compared with the prior art, the invention has the beneficial effects that:
the magnetic core and the secondary winding are equally divided into four parts, air gaps are formed among the parts of the magnetic core, and under the direct current component, the secondary current waveform distortion of the transformer with the air gaps is small, and the output is stable; meanwhile, the secondary winding is divided into a plurality of sections and electromagnetic balance in the magnetic core can be realized through a specific serial-parallel connection mode, and secondary current is not influenced by different positions of the primary through conductors; the transmission characteristics are stable after being disturbed.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a block diagram of a high accuracy current measurement device for on-line detection according to an embodiment of the present invention;
FIG. 2 is a schematic cross-sectional view of an embodiment of the present invention;
FIG. 3 is a schematic view of an outer shield shell according to an embodiment of the present invention;
fig. 4 is a schematic view of an outer shield shell locking mechanism according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.
The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
The terms "first," "second," and the like, are used merely to distinguish one entity or action from another entity or action, and are not to be construed as indicating or implying any actual such relationship or order between such entities or actions.
As shown in fig. 1 to 4, the high-accuracy current measurement device for online detection according to the embodiment of the present application includes a magnetic core, wherein the magnetic core is divided into four halves, namely, a first partial magnetic core 1, a second partial magnetic core 2, a third partial magnetic core 3 and a fourth partial magnetic core 4; the first partial core 1, the second partial core 2, the third partial core 3 and the fourth partial core 4 are connected in sequence end to form a complete ring. A first air gap is formed at the joint of the first partial magnetic core 1 and the second partial magnetic core 2, a second air gap is formed at the joint of the second partial magnetic core 2 and the third partial magnetic core 3, a third air gap is formed at the joint of the third partial magnetic core 3 and the fourth partial magnetic core 4, and a fourth air gap is formed at the joint of the fourth partial magnetic core 4 and the first partial magnetic core 1;
the secondary winding and the outer shielding shell 16 are also included, the secondary winding is divided into four sections, the four sections of secondary windings are respectively wound on the four partial magnetic cores, and the four sections of secondary windings are all wound in the same direction; and the tail end 6 of the first section secondary winding is connected with the tail end 10 of the third section secondary winding in series; the head end 5 of the first section secondary winding, the head end 7 of the second section secondary winding and the tail end 12 of the fourth section secondary winding are connected in parallel to form a secondary wire outlet end, and the head end 9 of the third section secondary winding, the tail end 8 of the second section secondary winding and the head end 11 of the fourth section secondary winding are connected in parallel to form another secondary wire outlet end.
Optionally, the lengths of the first partial magnetic core 1 and the third partial magnetic core 3 are 1/6 of the whole magnetic core; the length of the second partial magnetic core 2 and the fourth partial magnetic core 4 is 1/3 of the whole magnetic core.
Optionally, the magnetic shielding device further comprises two pairs of shielding windings, wherein one pair of shielding windings is wound on the first partial magnetic core 1 and the third partial magnetic core 3; another pair of said shielding windings is wound around said second partial core 2 and said fourth partial core 4. The winding direction inside each pair of shielding windings is opposite and the number of turns is the same.
Optionally, the electromagnetic shielding device further comprises an electromagnetic shielding layer 13, wherein the electromagnetic shielding layer 13 is poured on the magnetic core and is used for isolating the magnetic core, the secondary winding and the shielding winding 14; the electromagnetic shielding layer 13 is divided into two layers and is respectively arranged between the magnetic core and the secondary winding and between the secondary winding and the shielding winding 14; the material of the electromagnetic shielding layer may be an insulating resin.
Optionally, a protective shielding shell is further included, the shielding shell includes an outer shell 16 and an inner shielding layer 15, and the cross section of the inner shielding layer 15 is rectangular.
Optionally, the insulating resin is coagulated between the magnetic core and the secondary winding outer shielding shell, and the insulating gel layer is modified, poured and packaged at 150-180 ℃ by adopting epoxy resin.
Optionally, the soft magnetic material layer is further included, the soft magnetic material is distributed at the end part of the local iron core in an annular strip shape, the end part of the soft magnetic material is flush with the end part of the local iron core, and the thickness of the soft magnetic material is smaller than the radius of the coil.
Optionally, the shielding device further comprises a locking mechanism, wherein the locking mechanism comprises a first locking block and a second locking block, the outer shielding shell is divided into a left half shell and a right half shell, the left half shell and the right half shell are semi-annular, one end of each half shell is hinged, and the other end of each half shell is abutted; the first locking block and the second locking block are respectively arranged at the abutting end parts of the left half shell and the right half shell, when the left half shell is abutted with the right half shell, the first locking block can be inserted into the second locking block, at least one locking hole is formed in the first locking block, at least one T-shaped hole is formed in the second locking block, a T-shaped bolt is arranged in the T-shaped hole, and when the first locking block is inserted into the second locking block, the lower end of the T-shaped bolt can be inserted into the locking hole to complete locking; when the left half shell and the right half shell are required to be opened, the auxiliary rod is required to jack the T-shaped bolt from the bottom of the locking hole, so that the first locking block and the second locking block are separated, and the left half shell and the right half shell can be separated. The locking mechanism can stabilize the air gap distance between the left half shell and the right half shell, does not change during measurement, and is safer in remote operation when the auxiliary rod is used for jacking.
The magnetic core and the secondary winding are equally divided into four parts, air gaps are formed among the parts of the magnetic core, and under the direct current component, the secondary current waveform distortion of the transformer with the air gaps is small, and the output is stable; meanwhile, the secondary winding is divided into a plurality of sections and electromagnetic balance in the magnetic core can be realized through a specific serial-parallel connection mode, and secondary current is not influenced by different positions of the primary through conductors; the transfer characteristic is stable after being interfered, and in addition, the high-accuracy current measurement device is provided with insulation measures, so that the primary current of the current transformer for the distribution network can be safely and accurately collected.
The foregoing is merely exemplary embodiments of the present application and is not intended to limit the scope of the present application, and various modifications and variations may be suggested to one skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.
Claims (8)
1. The high-accuracy current measuring device for on-line detection is characterized by comprising a magnetic core, wherein the magnetic core is divided into four parts, namely a first partial magnetic core, a second partial magnetic core, a third partial magnetic core and a fourth partial magnetic core; the first partial magnetic core, the second partial magnetic core, the third partial magnetic core and the fourth partial magnetic core are sequentially connected end to form a complete ring, a first air gap is formed at the joint of the first partial magnetic core and the second partial magnetic core, a second air gap is formed at the joint of the second partial magnetic core and the third partial magnetic core, a third air gap is formed at the joint of the third partial magnetic core and the fourth partial magnetic core, and a fourth air gap is formed at the joint of the fourth partial magnetic core and the first partial magnetic core;
the secondary winding is divided into four sections, the four sections of secondary windings are respectively wound on the four partial magnetic cores, and the four sections of secondary windings are wound in the same direction; and the tail end of the first section of secondary winding is connected with the tail end of the third section of secondary winding in series; the head end of the first section secondary winding, the head end of the second section secondary winding and the tail end of the fourth section secondary winding are connected in parallel to form a secondary outlet end, and the head end of the third section secondary winding, the tail end of the second section secondary winding and the head end of the fourth section secondary winding are connected in parallel to form another secondary outlet end.
2. The high-accuracy current measurement device for on-line detection according to claim 1, wherein the lengths of the first partial magnetic core and the third partial magnetic core are each 1/6 of the entire magnetic core; the lengths of the second partial magnetic core and the fourth partial magnetic core are 1/3 of the whole magnetic core.
3. The high-accuracy current measurement device for on-line detection according to claim 2, further comprising two pairs of shield windings, one pair of the shield windings being wound around the first partial magnetic core and the third partial magnetic core; the other pair of shielding windings are wound on the second partial magnetic core and the fourth partial magnetic core, and the winding directions inside each pair of shielding windings are opposite and the number of turns is the same.
4. A high accuracy current measurement apparatus for on-line detection as claimed in claim 3, further comprising an electromagnetic shielding layer, said electromagnetic shielding layer being cast on said magnetic core for isolating the magnetic core, secondary winding and shield winding; the electromagnetic shielding layer is divided into two layers and is respectively arranged between the isolation magnetic core and the secondary winding and between the secondary winding and the shielding winding; the material of the electromagnetic shielding layer may be an insulating resin.
5. The high accuracy current measurement device for on-line detection of claim 4, further comprising a protective shield housing, wherein the shield housing comprises an outer housing and an inner shield layer, wherein the inner shield layer has a rectangular cross section.
6. The high-accuracy current measurement device for on-line detection according to claim 5, wherein the insulating resin is condensed between the magnetic core and the secondary winding outer shielding shell, and the insulating gel layer is subjected to modified pouring encapsulation at 150-180 ℃ by using epoxy resin.
7. The high accuracy current measurement device for on-line detection as set forth in claim 6, further comprising a soft magnetic material layer, wherein the soft magnetic material is distributed in a ring shape at the end of the partial iron core, the end of the soft magnetic material is flush with the end of the partial iron core, and the thickness of the soft magnetic material is smaller than the radius of the coil.
8. The high accuracy current measuring device for on-line measuring of claim 7, wherein the outer shield case is divided into a left half case and a right half case, both of which are semi-ring-shaped, and one end of the left half case is hinged to one end of the right half case, and the other end is connected by a locking block.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410048741.0A CN117871926A (en) | 2024-01-12 | 2024-01-12 | High-accuracy current measurement device for online detection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410048741.0A CN117871926A (en) | 2024-01-12 | 2024-01-12 | High-accuracy current measurement device for online detection |
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| Publication Number | Publication Date |
|---|---|
| CN117871926A true CN117871926A (en) | 2024-04-12 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410048741.0A Pending CN117871926A (en) | 2024-01-12 | 2024-01-12 | High-accuracy current measurement device for online detection |
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| Country | Link |
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| CN (1) | CN117871926A (en) |
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- 2024-01-12 CN CN202410048741.0A patent/CN117871926A/en active Pending
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