CN115097188A - Large-caliber AC/DC current sensor based on zero magnetic flux principle - Google Patents
Large-caliber AC/DC current sensor based on zero magnetic flux principle Download PDFInfo
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- CN115097188A CN115097188A CN202210741078.3A CN202210741078A CN115097188A CN 115097188 A CN115097188 A CN 115097188A CN 202210741078 A CN202210741078 A CN 202210741078A CN 115097188 A CN115097188 A CN 115097188A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/0092—Arrangements for measuring currents or voltages or for indicating presence or sign thereof measuring current only
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
- G01R1/02—General constructional details
- G01R1/18—Screening arrangements against electric or magnetic fields, e.g. against earth's field
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
- G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
- G01R15/18—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using inductive devices, e.g. transformers
- G01R15/183—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using inductive devices, e.g. transformers using transformers with a magnetic core
- G01R15/185—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks using inductive devices, e.g. transformers using transformers with a magnetic core with compensation or feedback windings or interacting coils, e.g. 0-flux sensors
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Abstract
The invention provides a large-caliber alternating current and direct current sensor based on a zero magnetic flux principle, wherein a magnetic core induction unit of the sensor comprises two direct current iron core windings, an alternating current iron core winding and a shielding structure; any one of the direct current iron core windings comprises a direct current iron core, a first bracket, a direct current coil and a first shielding layer, and the two direct current iron core windings are vertically superposed and shielded by the first shielding layer; the alternating current iron core winding comprises an alternating current iron core, a second support, a compensation coil, an alternating current coil and a third support; the alternating current iron core is arranged in the second support, is superposed above the two direct current windings and is shielded by the second shielding layer, and the outer layer is sequentially wound with the compensation coil and the alternating current coil, is shielded by the third shielding layer and is arranged in the third support for packaging; and the core penetrating caliber of the magnetic core induction unit meets the insulation requirement distance. Thereby better meeting the application of measuring current on high-voltage lines.
Description
[ technical field ] A method for producing a semiconductor device
The invention relates to a current measuring device in a high-voltage environment, in particular to an alternating current and direct current sensor based on a zero magnetic flux principle.
[ background ] A method for producing a semiconductor device
The large current measurement is widely applied to the fields of electrolysis plants, high-speed rails, electric vehicles and the like, and the current sensor is widely concerned in the field of precise measurement of large current as a special instrument for measuring current.
According to different measurement principles, current sensors can be divided into:
(1) an electromagnetic current sensor is composed of an iron core and two windings (primary winding and secondary winding) wound on the iron core, according to the electromagnetic induction principle, after current flows into the primary side, a magnetic field is established on the iron core, and induced current is generated on the secondary winding.
(2) The shunt adopts stray inductance, the very little shunt of electric capacity to convert electric current into voltage mainly based on ohm's law, but is subject to the fuel factor of shunt, is difficult to guarantee the degree of accuracy when being surveyed electric current great.
(3) The Rogowski coil is similar to an electromagnetic coil in structure, and is manufactured by uniformly winding a lead on a non-magnetic material, and the induction coil surrounds the lead passing through a current to be measured, so that a variable current can be induced. The rogowski coil has a wide frequency band and is not influenced by the magnetic saturation of the iron core, but is influenced by the frequency, and only can measure alternating current signals below a lower-limit cutoff frequency of the frequency.
(4) The magneto-optical current sensor is mainly based on the Faraday effect, and a photosensitive element with the Faraday effect can generate angular rotation on a polarization plane of light after being influenced by a current magnetic field, and can be used for measuring the measured current based on the relation between the rotation angle and the current magnitude. The magneto-optical current sensor also has the characteristics of wide frequency band and no magnetic saturation, but is not beneficial to the measurement occasion of small current.
(5) The giant magnetoresistance current sensor is mainly based on the giant magnetoresistance effect, in a multi-layer metal film with the thickness of a few nanometers, different spin states from current-carrying electrons and different effects of a magnetic field cause resistance value changes, namely, the angle between the applied magnetic field and a sensor reference layer determines the resistance change of the metal film, so that the giant magnetoresistance current sensor can be used for measuring current. Giant magnetoresistive current sensors have a wide measurement band, but are susceptible to magnetic saturation.
(6) The optical fiber current sensor, as a phase modulation type optical fiber sensor, converts the change of current into the change of optical wave phase in optical fiber, and detects the current passing through a sensing ring by coherent detection and digital closed loop feedback technology. The optical fiber current sensor has the characteristics of good insulating property, small volume, light weight, large measurement range, good dynamic characteristic, full digitalization, capability of simultaneously measuring alternating current and direct current signals and the like, but the measurement device is complex.
(7) The fluxgate current sensor measures a weak magnetic field by utilizing the nonlinear relation between the magnetic induction intensity and the magnetic field intensity of a high-permeability iron core in a measured magnetic field under the saturation excitation of an alternating magnetic field, and measures current according to the weak magnetic field. The fluxgate current sensor has the characteristics of high accuracy, high resolution, high sensitivity and the like.
And the zero-flux current sensor is one of fluxgate sensors. The zero-flux current sensor is widely applied to industries such as power batteries, new energy automobile industry, large-scale medical equipment, urban rail transit industry, new energy power generation and the like, and main manufacturers at home and abroad comprise LEM of Swiss, Danish DANISENSE, German GMC, Japan YOKOGAWA, Galaxy electricity, Jinghenkou electricity, cloud of Cheyne, Beijing forest society, Wuhan Tianrui, Ankery, Nanjing Xinrui spectrum, Nanjing odd Hoo, Ningbo middle-sized vehicles and the like. However, the caliber of the existing zero-flux current sensor for passing through a current lead to be measured is generally not large, such as the sensor DS1000UBSA with rated current 1000A produced by Denmark DANISENSE, the diameter of a sensor through hole is only 26.6 mm; for a 2000A rated sensor DS2000IDLA, the sensor orifice diameter is only 68 mm. The feed-through caliber only needs to meet the requirement that a measured wire can pass through, and does not consider safe insulation distance, so the feed-through caliber cannot meet the requirement on the insulation distance when measuring current on a high-voltage line.
[ summary of the invention ]
In view of this, the technical problem to be solved by the present invention is to provide a large-diameter ac/dc current sensor based on the zero magnetic flux principle, wherein the through-bore diameter meets the insulation requirement distance by redesigning the inner diameters of three iron cores of the current sensor, and the application occasion of measuring current on a high-voltage line is better met by combining with the design of an insulation shielding structure.
In order to achieve the purpose of the invention, the embodiment of the invention adopts the technical scheme that: a large-caliber AC/DC current sensor based on the zero magnetic flux principle is characterized in that a magnetic core induction unit of the sensor comprises two DC iron core windings, an AC iron core winding and a shielding structure;
the shielding structure comprises a first shielding layer, a second shielding layer and a third shielding layer, the first shielding layer is arranged in a suspended mode and is not electrically connected, and the second shielding layer and the third shielding layer are arranged in a grounded mode;
any one direct current iron core winding comprises a direct current iron core, a first support and a direct current coil, wherein the direct current iron core is arranged in the first support, and the direct current coil is wound on the first support; the two direct current iron core windings are overlapped up and down and are shielded through the first shielding layer;
the alternating current iron core winding comprises an alternating current iron core, a second support, a compensation coil, an alternating current coil and a third support; the alternating current iron core is arranged in the second support, is overlapped above the two direct current windings and is shielded through the second shielding layer to form an overlapped structure, a compensation coil and the alternating current coil are sequentially wound on the outer layer of the overlapped structure, then are shielded through the third shielding layer, and are arranged in the third support to be packaged to form a complete magnetic core induction unit;
and the core penetrating caliber of the magnetic core induction unit meets the insulation requirement distance. Further, when the rated current of the large-caliber AC/DC current sensor is 1000A and the voltage of the high-voltage line is 10KV, the core penetrating caliber of the magnetic core induction unit is 70-88; when the rated current of the large-caliber AC/DC current sensor is 1000A and the voltage of the high-voltage line is 35KV, the core penetrating caliber of the magnetic core induction unit is 120-150.
Further, the direct current iron core is a circular iron core wound with amorphous materials; the alternating current iron core is a circular ring iron core made of permalloy; the first bracket and the third bracket are both hard polytetrafluoroethylene shells; the second bracket is a hard-shell plastic shell.
The invention has the advantages that: by adopting the iron core with the customized special caliber and matching with the design of a better insulation shielding structure, compared with the current sensor with the same class rated current grade, the invention not only meets the requirement of the same degree of accuracy grade, but also better meets the requirement of the safety insulation distance when being applied to the current measurement of a high-voltage line.
[ description of the drawings ]
The invention will be further described with reference to the following examples with reference to the accompanying drawings.
Fig. 1 is a schematic diagram of the core and windings of a zero-flux current sensor of the present invention.
Fig. 2 is a schematic circuit diagram of a zero-flux current sensor of the present invention.
Fig. 3 is a schematic cross-sectional view of a magnetic core sensing unit of the zero-flux current sensor according to the present invention.
Fig. 4 is a schematic diagram of the structure of three cores of the zero-flux current sensor of the present invention.
Fig. 5 is a schematic structural diagram of a magnetic core induction unit of the zero-flux current sensor of the present invention.
[ detailed description ] embodiments
The embodiment of the invention provides a large-caliber alternating current-direct current sensor based on a zero magnetic flux principle, the inner diameters of three iron cores of the current sensor are redesigned, so that the through caliber meets the insulation required distance, and the application occasion of measuring current on a high-voltage circuit is better met by combining the design of an insulation shielding structure.
In order to solve the above problems, the technical solution in the embodiments of the present invention has the following general idea: the invention better meets the requirement on safe insulation distance when being applied to high-voltage line current measurement by adopting the customized iron core with special caliber and matching with the design of a better insulation shielding structure.
For better understanding of the above technical solutions, the following detailed descriptions will be provided in conjunction with the drawings and the detailed description of the embodiments.
The zero-flux current sensor is one of fluxgate sensors, the basic structure of the zero-flux current sensor is formed by combining a double-iron-core magnetic modulation type current comparator and an alternating current comparator, and the feedback compensation technology is utilized to ensure the automatic balance of ampere turns of a main iron core, so that the stable measurement of alternating current and direct current closed loops is realized.
Fig. 1 is a schematic diagram of an iron core and windings of a zero-flux current sensor, which mainly includes three iron cores, four winding coils, a zero-flux detection module, an amplification circuit module, an addition circuit module, and an output circuit. The three iron cores are respectively T1, T2 and T3, and the four winding coils comprise two excitation windings X1/1-X1/3 and X1/2-X1/4, one feedback winding X2/1-X2/2 and one compensation winding X2/3-X2/4.
The iron cores in the two excitation windings are made of the same magnetic material with the same cross-sectional area and the same magnetic path length, and the current I to be measured P Connected to all cores via primary windings.
Two ends of the excitation winding with the same name are connected, namely are in anti-series connection, so that the direction of the magnetic flux generated by the direct current signal winding on one iron core and the direction of the magnetic flux generated by the alternating current excitation winding are consistent, and the direction of the magnetic flux generated by the other iron core is just opposite, as shown in fig. 2. When a measured direct current Ip flows through the primary winding, a direct current magnetic flux is generated on the two field cores, one magnetic flux is increased and the other magnetic flux is decreased, the sum of the areas of the magnetizing currents of the two coils in any half period is detected by a circuit by utilizing the nonlinear characteristic of the magnetic permeability of the magnetic core, and the sum changes along with the change of Ip, so that the value is the detected signal value of the direct current Ip. This signal is amplified to generate a compensation current Ic, which is fed back to the compensation coil to cancel the magnetic flux generated by Ip on the two excitation cores, so that the dc component of the magnetic flux on the two excitation cores tends to 0, thereby reducing the detected signal value, and as a result, the magnetic fluxes generated by Ip and Ic on the two excitation cores are balanced. And measuring Ic through the output resistor RL to obtain the measured current Ip.
When the detected alternating current Ip flows through the primary winding, the induced voltage signal induced by the direct feedback winding is input to the input end of the amplifier, and the compensation current Ic is also generated to counteract the magnetic flux generated by Ip on the two excitation iron cores, so that the magnetic fluxes on the two excitation iron cores are balanced, and the Ip is obtained.
Example one
As shown in fig. 3, the magnetic core sensing unit 100 of the zero-flux current sensor of the present invention mainly includes an iron core winding and a shielding structure 3, the iron core winding includes two dc iron core windings 1 and an ac iron core winding 2, and the shielding structure 3 is designed in the iron core winding in an inserting manner.
The shielding structure 3 comprises a first shielding layer 31, a second shielding layer 32 and a third shielding layer 33, the first shielding layer 31 is suspended and is not electrically connected, and the second shielding layer 32 and the third shielding layer 33 are grounded.
Any one of the direct current iron core windings 1 comprises a direct current iron core 11, a first bracket 12 and a direct current coil 13, wherein the direct current iron core 11 is arranged in the first bracket 12, and the direct current coil 13 is wound on the first bracket 12; and the two dc core windings 1 are stacked up and down and shielded by the first shielding layer 31.
The alternating current iron core winding 2 comprises an alternating current iron core 21, a second bracket 22, a compensation coil 23, an alternating current coil 24 and a third bracket 25; alternating current core 21 locates in second support 22 and superposes in two direct current winding 1's top and passes through second shielding layer 32 shields, forms the stack structure, the skin of stack structure in proper order around establish compensating coil 23 with alternating current coil 24 back is passed through third shielding layer 33 shields, again set up in encapsulate in third support 25, form and form complete magnetic core induction unit 100.
The first shielding layer 31 is used for shielding the interference of an external magnetic field to the dc core 11, and the second shielding layer 32 is used for preventing the interference of an electrostatic field to the three cores; the first support 12, the second support 22 and the third support 25 can not only support and fix the iron core, but also further improve the insulation strength of the sensor through the selection of materials.
As shown in fig. 4 and 5, the feedthrough aperture 102 of the magnetic core inductive unit 100 satisfies the insulation requirement distance. In this embodiment, the rated current of the large-caliber ac/dc current sensor is 1000A, and when the voltage of the high-voltage line is 10KV, the core-through caliber of the magnetic core induction unit 100 is 70-88 mm, and the core-through caliber of this size can completely satisfy the insulation requirement distance, and will not cause too large influence on the process and material selection of the factory due to too large caliber. When selecting the iron core, on the premise of meeting the requirement of the core-through caliber 102, considering the size of the bracket, the winding of the coil, the arrangement of the shielding structure and the like, the inner diameter of the direct current iron core and the alternating current iron core can be 120mm, the outer diameter is 145mm, and the height is 25mm, which is preferable.
When the rated current of the large-caliber AC/DC current sensor is 1000A and the secondary current is 1A, the DC coil and the compensation coil are both 250 turns, and the AC coil is 1000 turns.
The direct current iron core 11 is a circular iron core wound by amorphous materials, and the alternating current iron core 21 is a circular iron core made of permalloy; the cooperation of the two materials can meet better magnetic permeability, thereby enabling the sensor to test more accurately and improving the sensitivity.
The first bracket 12 and the third bracket 25 are both hard polytetrafluoroethylene shells; the polytetrafluoroethylene material has high hardness and good insulating strength and can generally provide 10 12～15 The insulation strength of Europe, thereby further improving the insulation effect of the sensor.
The second bracket is a hard-shell plastic shell, so that a better supporting effect is provided for the alternating-current iron core.
Example two
The second embodiment is different from the first embodiment in that the first embodiment is used for adapting to the test when the voltage of the high-voltage line is 10KV, and the second embodiment is used for adapting to the test when the voltage of the high-voltage line is 35KV, so that the difference in structure is as follows:
when the rated current of the large-caliber AC/DC current sensor is 1000A and the voltage of the high-voltage line is 35KV, the core penetrating caliber of the magnetic core induction unit is 120-150 mm. Similarly, the core-through caliber with the size can completely meet the insulation requirement distance, and the too large caliber cannot cause too large influence on the process and material selection of a factory. When the iron core is selected, on the premise of meeting the requirement of the core-through caliber, the sizes of the supports, the coil winding, the arrangement of the shielding structures and the like are considered, and the inner diameters of the direct current iron core and the alternating current iron core can be 180mm, the outer diameter is 210mm, and the height is 30 mm.
The invention has the advantages that: by adopting the iron core with the customized special caliber and matching with the design of a better insulation shielding structure, compared with the current sensor with the same class rated current grade, the invention not only meets the requirement of the same degree of accuracy grade, but also better meets the requirement of the safety insulation distance when being applied to the current measurement of a high-voltage line.
Although specific embodiments of the invention have been described above, it will be understood by those skilled in the art that the specific embodiments described are illustrative only and are not limiting upon the scope of the invention, and that equivalent modifications and variations can be made by those skilled in the art without departing from the spirit of the invention, which is to be limited only by the appended claims.
Claims (3)
1. The utility model provides a heavy-calibre alternating current-direct current sensor based on zero magnetic flux principle which characterized in that: the magnetic core induction unit of the sensor comprises two direct current iron core windings, an alternating current iron core winding and a shielding structure;
the shielding structure comprises a first shielding layer, a second shielding layer and a third shielding layer, the first shielding layer is arranged in a suspended mode and is not electrically connected, and the second shielding layer and the third shielding layer are arranged in a grounded mode;
any one direct current iron core winding comprises a direct current iron core, a first support and a direct current coil, wherein the direct current iron core is arranged in the first support, and the direct current coil is wound on the first support; the two direct current iron core windings are overlapped up and down and are shielded through the first shielding layer;
the alternating current iron core winding comprises an alternating current iron core, a second support, a compensation coil, an alternating current coil and a third support; the alternating current iron core is arranged in the second support, is overlapped above the two direct current windings and is shielded through the second shielding layer to form an overlapped structure, a compensation coil and the alternating current coil are sequentially wound on the outer layer of the overlapped structure, then are shielded through the third shielding layer and are arranged in the third support for packaging, and a complete magnetic core induction unit is formed;
and the core penetrating caliber of the magnetic core induction unit meets the insulation requirement distance.
2. A large-caliber ac/dc current sensor based on the zero-flux principle as claimed in claim 1, wherein:
when the rated current of the large-caliber AC/DC current sensor is 1000A and the voltage of a high-voltage line is 10KV, the core penetrating caliber of the magnetic core induction unit is 70-88 mm;
when the rated current of the large-caliber AC/DC current sensor is 1000A and the voltage of the high-voltage line is 35KV, the core penetrating caliber of the magnetic core induction unit is 120-150 mm.
3. A large-caliber ac/dc current sensor based on the zero-flux principle as claimed in claim 1, wherein:
the direct current iron core is a circular iron core wound by amorphous materials,
the alternating current iron core is a circular ring iron core made of permalloy;
the first bracket and the third bracket are both hard polytetrafluoroethylene shells;
the second bracket is a hard-shell plastic shell.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202210741078.3A CN115097188A (en) | 2022-06-28 | 2022-06-28 | Large-caliber AC/DC current sensor based on zero magnetic flux principle |
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| CN202210741078.3A CN115097188A (en) | 2022-06-28 | 2022-06-28 | Large-caliber AC/DC current sensor based on zero magnetic flux principle |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116500330A (en) * | 2023-06-27 | 2023-07-28 | 中国科学院合肥物质科学研究院 | Detection device for secondary loop current of superconducting transformer |
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2022
- 2022-06-28 CN CN202210741078.3A patent/CN115097188A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116500330A (en) * | 2023-06-27 | 2023-07-28 | 中国科学院合肥物质科学研究院 | Detection device for secondary loop current of superconducting transformer |
| CN116500330B (en) * | 2023-06-27 | 2023-09-08 | 中国科学院合肥物质科学研究院 | Detection device for secondary loop current of superconducting transformer |
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