A magnetic pole, a magnetic field generating device and a method

Abstract

The present invention discloses a magnetic pole, comprising: an excitation coil, used to generate current under the action of a voltage signal, and generate a magnetic field based on the current; a magnetic conductive member, coated on the outside of the excitation coil, used to regulate the magnetic field generated by the excitation coil, and enhance the magnetic field away from the position of the excitation coil to generate a uniform magnetic field; wherein the cross-sectional shape of the magnetic conductive member is C-shaped, the C-shaped opening is located on the inner side of the excitation coil, and the cavity formed at the C-shaped opening is an excitation chamber, and the uniform magnetic field generated by the magnetic conductive member is distributed in the excitation chamber. The present invention also provides a magnetic field generating device and method, comprising: a signal generator generates a voltage signal of a preset frequency; a power amplifier amplifies the voltage signal; the magnetic pole generates a uniform magnetic field according to the power-amplified voltage signal; the magnetic field generating device of the present invention can generate a large-size, uniformly distributed, multi-frequency composite, and amplitude-adjustable magnetic field, and the device has a simple structure and convenient function adjustment.

Description

Technical Field

[0001] The present invention relates to the field of high voltage and insulation technology, and more specifically, to a magnetic pole, a magnetic field generating device and a method. Background Art

[0002] Leakage current is closely related to the insulation state of power equipment. Leakage current refers to the current formed between high potential and low potential, inside the insulation and on the surface of the insulation under the condition of applied voltage. The leakage current measurement of power equipment belongs to the precision measurement category of high voltage, strong magnetic field and microcurrent, generally μA level / mA level, which is very susceptible to interference from the external environment and has high requirements for the measurement method. Leakage current is usually measured by non-contact electromagnetic induction elements, so such sensor devices are very susceptible to external magnetic field interference, especially the power frequency magnetic field with similar frequency. The results of the full voltage and full current test of high-voltage bushings conducted by China Electric Power Research Institute show that when the load current in the high-voltage bushing conductive rod changes in the range of 0-1600A, the magnetic induction intensity generated at the end screen of the bushing is about 1.2mT. The magnetic field interference causes the measured value of the leakage current at the end screen of the bushing to be compared with the true value (measured when the current carrying current of the rod is 0A). The maximum phase error is 11° and the maximum amplitude error is +78%. It can be seen that the power frequency magnetic field has a very serious impact on the accuracy of leakage current measurement. The same problem will also exist in the leakage current measurement of other power equipment such as lightning arresters and transformers. This measurement error caused by magnetic field interference is unacceptable for equipment insulation status monitoring devices. Therefore, in order to improve the measurement accuracy of the sensor, it is urgent to study the mechanism of the influence of the magnetic field on the current sensor.

[0003] To conduct research on the mechanism of the influence of magnetic field on current sensor, the first test equipment needed is the magnetic field generating device. First, the magnetic field size that can be generated is large, and the overall distribution uniformity of the magnetic field is extremely high, so as to reduce the adverse effects of the performance of the test instrument itself on the research; second, it is required to simulate the actual magnetic field environment around the power equipment, that is, the magnetic field can be superimposed with multiple frequencies, the frequency range is 0Hz-2500Hz, and the magnetic field intensity at different frequencies is adjustable. Through investigation, it is found that the existing magnetic field generation technology mainly includes: ① an electromagnetic field generator (201910109628.8), ② a fixed electromagnetic vortex magnetic field generator (201910090158.5). The main problem described in the two patents is that the magnetic field inside the coil will show a trend of gradually increasing magnetic field intensity from the center to the outside, and as the coil size increases, the magnetic field change trend becomes more obvious, and the uniformity cannot meet the research requirements. In addition, the two technologies do not provide a solution to the multi-frequency composite of the magnetic field. The existing technology has problems such as poor uniformity of large-scale magnetic fields and no multi-frequency composite function.

[0004] Therefore, in order to study the mechanism of the influence of magnetic field on current sensor, a magnetic field generating device capable of generating uniform magnetic field is needed. Summary of the invention

[0005] The present invention provides a magnetic pole, a magnetic field generating device and a method to solve the problem of how to generate a uniform magnetic field.

[0006] In order to solve the above problem, according to one aspect of the present invention, a magnetic pole is provided, the magnetic pole comprising: an excitation coil and a magnetic conductive member; wherein,

[0007] The excitation coil is used to generate a current under the action of a voltage signal and generate a magnetic field based on the current;

[0008] The magnetic conductive member is coated on the outside of the excitation coil and is used to control the magnetic field generated by the excitation coil and enhance the magnetic field away from the excitation coil to generate a uniform magnetic field;

[0009] The cross-sectional shape of the magnetic conductive component is C-shaped, the C-shaped opening is located inside the excitation coil, the cavity formed at the C-shaped opening is the excitation chamber, and the uniform magnetic field generated by the magnetic conductive component is distributed in the excitation chamber.

[0010] Preferably, the excitation coil is circular and is formed by winding a metal wire in a single direction.

[0011] Preferably, the magnetic conductive component comprises: at least one layer of magnetic conductive structure. When there are multiple layers of magnetic conductive structure, the multiple layers of magnetic conductive structure are sequentially wrapped around the outside of the excitation coil, and the magnetic permeability of different layers of magnetic conductive structure increases sequentially from the inside to the outside.

[0012] Preferably, the magnetic conductive part and the C-shaped opening present a waist-shaped structure as a whole, the height of the C-shaped opening is less than or equal to a preset multiple of the radius of the waist-shaped structure where the outermost magnetic conductive structure is located; the thickness of each layer of the magnetic conductive structure is less than or equal to a first preset threshold; the distance between the inner wall of the innermost magnetic conductive structure and the center line of the excitation coil is less than or equal to a second preset threshold.

[0013] Preferably, the first preset threshold is 20 mm; the preset multiple is 20%; and the second preset threshold is 10 mm.

[0014] Preferably, the magnetic conductive structure is made of metal material, and the magnetic permeability of the innermost magnetic conductive structure is greater than or equal to a third preset threshold.

[0015] Preferably, the third preset threshold is 200. According to another aspect of the present invention, a magnetic field generating device is provided, the magnetic field generating device comprising: a signal generator, a power amplifier and the magnetic pole as described above; wherein,

[0016] The signal generator is connected to the power amplifier and is used to generate a voltage signal of a preset frequency and send the voltage signal to the power amplifier;

[0017] The power amplifier is connected to the magnetic pole and is used to amplify the power of the voltage signal and send the power-amplified voltage signal to the magnetic pole;

[0018] The magnetic pole is used to generate a uniform magnetic field according to the power-amplified voltage signal.

[0019] According to another aspect of the present invention, there is provided a magnetic field generating method based on the above magnetic field generating device, the method comprising:

[0020] The signal generator generates a voltage signal of a preset frequency and sends the voltage signal to the power amplifier;

[0021] The power amplifier amplifies the voltage signal and sends the amplified voltage signal to the magnetic pole.

[0022] Preferably, the method further comprises:

[0023] The magnetic pole generates a uniform magnetic field according to the power-amplified voltage signal.

[0024] Preferably, the method further comprises:

[0025] The voltage signal output by the signal generator is adjusted to change the waveform of the uniform magnetic field.

[0026] Preferably, the method further comprises: determining the magnetic permeability of each layer of the magnetic conductive structure in the following manner, including:

[0027]

[0028] Among them, μ i is the magnetic permeability of the i-th layer of the magnetic conductive structure; μ1 is the magnetic permeability of the innermost layer of the magnetic conductive structure; r0 is the distance between the inner wall of the innermost layer of the magnetic conductive structure and the center line of the excitation coil; d is the thickness of the magnetic conductive structure.

[0029] The present invention provides a magnetic pole, comprising: an excitation coil, used to generate a current under the action of a voltage signal, and to generate a magnetic field based on the current; a magnetic conductive member, coated on the outside of the excitation coil, used to regulate the magnetic field generated by the excitation coil, and to generate a uniform magnetic field by enhancing the magnetic field away from the excitation coil; wherein the cross-sectional shape of the magnetic conductive member is C-shaped, the C-shaped opening is located on the inner side of the excitation coil, and the cavity formed at the C-shaped opening is an excitation chamber, and the uniform magnetic field generated by the magnetic conductive member is distributed in the excitation chamber. The present invention also provides a magnetic field generating device and method, which can generate a large-sized, uniformly distributed, multi-frequency composite, and amplitude-adjustable magnetic field based on a signal generator, a power amplifier, and a magnetic pole. The device has a simple structure and convenient function adjustment, and is particularly suitable for use in conducting scientific research related to magnetic fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0031] Figure 1 is a schematic structural diagram of a magnetic pole 100 according to an embodiment of the present invention;

[0032] Figure 2 is a front view of a magnetic pole according to an embodiment of the present invention;

[0033] Figure 3 is a cross-sectional view of a magnetic pole according to an embodiment of the present invention;

[0034] Figure 4 is a schematic structural diagram of a magnetic pole cross section according to an embodiment of the present invention;

[0035] Figure 5 is a schematic structural diagram of a magnetic field generating device 500 according to an embodiment of the present invention;

[0036] Figure 6 FIG. 6 is a flow chart of a method 600 for generating a magnetic field according to an embodiment of the present invention. DETAILED DESCRIPTION

[0037] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0038] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0039] Figure 1 FIG. 1 is a schematic diagram of the structure of a magnetic pole 100 according to an embodiment of the present invention. Figure 1 As shown, the magnetic pole 100 according to the embodiment of the present invention includes: an excitation coil 101 and a magnetic conductive member 102 .

[0040] Preferably, the excitation coil 101 is used to generate a current under the action of a voltage signal, and to generate a magnetic field based on the current.

[0041] Preferably, the magnetic conductive component 102 is wrapped around the outside of the excitation coil, and is used to regulate the magnetic field generated by the excitation coil, and enhance the magnetic field away from the excitation coil to generate a uniform magnetic field; wherein the cross-sectional shape of the magnetic conductive component is C-shaped, the C-shaped opening is located on the inner side of the excitation coil, and the cavity formed at the C-shaped opening is the excitation chamber, and the uniform magnetic field generated by the magnetic conductive component is distributed in the excitation chamber.

[0042] Preferably, the excitation coil is circular and is formed by winding a metal wire in a single direction.

[0043] Preferably, the magnetic conductive component comprises: at least one layer of magnetic conductive structure. When there are multiple layers of magnetic conductive structure, the multiple layers of magnetic conductive structure are sequentially wrapped around the outside of the excitation coil, and the magnetic permeability of different layers of magnetic conductive structure increases sequentially from the inside to the outside.

[0044] Preferably, the magnetic conductive part and the C-shaped opening present a waist-shaped structure as a whole, the height of the C-shaped opening is less than or equal to a preset multiple of the radius of the waist-shaped structure where the outermost magnetic conductive structure is located; the thickness of each layer of the magnetic conductive structure is less than or equal to a first preset threshold; the distance between the inner wall of the innermost magnetic conductive structure and the center line of the excitation coil is less than or equal to a second preset threshold.

[0045] Preferably, the first preset threshold is 20 mm; the preset multiple is 20%; and the second preset threshold is 10 mm.

[0046] Preferably, the magnetic conductive structure is made of metal material, and the magnetic permeability of the innermost magnetic conductive structure is greater than or equal to a third preset threshold.

[0047] Preferably, the third preset threshold is 200. The magnetic pole of the embodiment of the present invention includes an excitation coil and a magnetic conductive member. The magnetic pole can generate a current in the excitation coil under the action of a voltage, thereby generating a magnetic field. Then, through a multi-layer magnetic conductive structure with increasing magnetic permeability from the inside to the outside, the magnetic field away from the excitation coil is enhanced, so that the magnetic field is redistributed in the memory of the multi-layer magnetic conductive structure, and finally the uniformly regulated magnetic field is input to the upper and lower ends of the magnetic control room. Therefore, a uniform magnetic field is obtained in the magnetic control room, and the magnetic field waveform (frequency amplitude) can be adjusted by changing the output voltage signal of the signal generator.

[0048] Combination Figure 2 , Figure 3 and Figure 4 As shown, in an embodiment of the present invention, the excitation coil is formed by winding a metal wire in a single direction, and the shape after winding is circular, and the number of turns is preferably controlled to be 100-10000. When the number of turns is large, the inductive reactance of the excitation coil is large, which will inhibit the output of the high-frequency magnetic field. The magnetic conductive part is mainly used to regulate the magnetic field generated by the excitation coil. The magnetic conductive part is composed of multiple layers of metal materials with different magnetic permeabilities, and the cross-sectional shape of the magnetic conductive part is the English letter "C" shape, which is sequentially wrapped around the outside of the excitation coil. In order to improve the uniformity of the magnetic field, the thickness of each layer of the magnetic conductive structure is consistent, and the thickness d does not exceed 20mm. The magnetic conductive part and the C-shaped opening part present a waist-shaped structure as a whole, and the height D of the opening does not exceed 20% of the radius of the waist-shaped structure composed of the outermost layer of the magnetic conductive structure. There is no restriction on the number of layers n of the magnetic conductive structure, and it can be selected according to actual needs. The cavity formed by the "C"-shaped opening of the multi-layer magnetic conductive structure is the magnetic control chamber.

[0049] The measuring device of the present invention can generate a uniformly distributed magnetic field and can be used to measure the leakage current of power equipment. Since the magnetic field interference near the power equipment is very large, measuring equipment such as current transformers can be placed in the magnetic control room, and the magnetic field is generated by the magnetic field generating device, and the leakage current is measured using the current transformer to carry out magnetic field related research.

[0050] Figure 5 FIG. 5 is a schematic diagram of the structure of a magnetic field generating device 500 according to an embodiment of the present invention. Figure 5 As shown, the magnetic field generating device 500 provided in the embodiment of the present invention includes: a signal generator 501 , a power amplifier 502 and a magnetic pole 503 .

[0051] Preferably, the signal generator 501 is connected to the power amplifier, and is used to generate a voltage signal of a preset frequency, and send the voltage signal to the power amplifier;

[0052] Preferably, the power amplifier 502 is connected to the magnetic pole, and is used to amplify the power of the voltage signal and send the power-amplified voltage signal to the magnetic pole;

[0053] Preferably, the magnetic pole 503 is used to generate a uniform magnetic field according to the power-amplified voltage signal.

[0054] In the embodiment of the present invention, the signal generator is a function signal generator, which can generate voltage waveforms such as DC waveforms and sine waves, and the frequency can be adjusted between 0 Hz and 2500 Hz, and has a multi-frequency composite function. The power amplifier keeps the amplitude of the input voltage signal of the function signal generator unchanged and increases the maximum power that can be input. The magnetic pole 503 corresponds to the magnetic pole 100 in the previous embodiment, and will not be described in detail here.

[0055] The working principle of the magnetic field generating device of the embodiment of the present invention is as follows: first, a function signal generator is used to generate the required voltage signal, and then the voltage signal is input into a power amplifier, and the output power of the function signal generator is increased by the power amplifier. The output signal of the power amplifier is connected to the excitation coil of the magnetic pole, that is, the voltage signal is input into the excitation coil of the magnetic pole, and a current is generated in the excitation coil under the action of the voltage, thereby generating a magnetic field. Then the magnetic field is redistributed in the magnetic conductive part, and finally the uniformly regulated magnetic field is input into the upper and lower ends of the magnetic control room. Therefore, a uniform magnetic field is obtained in the magnetic control room, and the magnetic field waveform (frequency amplitude) can be adjusted by changing the output voltage signal of the signal generator.

[0056] The magnetic field generating device of the present invention can generate a large-sized, uniformly distributed, multi-frequency composite, and amplitude-adjustable magnetic field based on a signal generator, a power amplifier, and a magnetic pole. The device has a simple structure and convenient function adjustment, and is particularly suitable for use in conducting scientific research related to magnetic fields.

[0057] Figure 6 FIG. 6 is a flow chart of a method 600 for generating a magnetic field according to an embodiment of the present invention. Figure 6 As shown, the magnetic field generating method 600 based on the above magnetic field generating device provided in the embodiment of the present invention includes:

[0058] Step 601: A signal generator generates a voltage signal of a preset frequency and sends the voltage signal to a power amplifier.

[0059] Step 602: The power amplifier amplifies the voltage signal and sends the amplified voltage signal to the magnetic pole.

[0060] Preferably, the method further comprises: the magnetic pole generating a uniform magnetic field according to the power-amplified voltage signal.

[0061] Preferably, the method further comprises: adjusting the voltage signal output by the signal generator to change the waveform of the uniform magnetic field.

[0062] Preferably, the method further comprises: determining the magnetic permeability of each layer of the magnetic conductive structure in the following manner, including:

[0063]

[0064] Among them, μ i is the magnetic permeability of the i-th layer of the magnetic conductive structure; μ1 is the magnetic permeability of the innermost layer of the magnetic conductive structure; r0 is the distance between the inner wall of the innermost layer of the magnetic conductive structure and the center line of the excitation coil; d is the thickness of the magnetic conductive structure.

[0065] The magnetic field generating method 600 of the embodiment of the present invention corresponds to the magnetic field generating device 500 of another embodiment of the present invention, and will not be described in detail herein.

[0066] The principle of selecting the magnetic permeability of different layers of the multi-layer magnetic conductive parts is as follows: the magnetic conductive structure of each layer is marked as Si from the inside to the outside, and the innermost layer S1 is selected from a metal material with a relative magnetic permeability of μ1, and the preferred value of μ1 is not less than 200. The distance between the center line of the excitation coil and the inner wall of S1 is r0, and the size of r0 does not exceed 10mm. i It represents the magnetic permeability of the i-th layer of magnetic conductive structure. The selection principle of the magnetic permeability of the i-th layer of magnetic conductive structure is as follows:

[0067]

[0068] Wherein, i=1, 2, 3, ..., n, and n represents the total number of layers of the magnetic conductive structure.

[0069] The invention has been described above with reference to a few embodiments. However, it is readily apparent to a person skilled in the art that other embodiments than the ones disclosed above are equally within the scope of the invention, as defined by the appended patent claims.

[0070] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a / said / the [means, components, etc.]" are to be openly interpreted as at least one instance of the means, components, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not necessarily have to be performed in the exact order disclosed, unless explicitly stated otherwise.

[0071] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0072] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0073] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0074] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A magnetic pole, characterized in that: The magnetic pole comprises: an excitation coil and a magnetic conductive member; wherein, The excitation coil is used to generate a current under the action of a voltage signal and generate a magnetic field based on the current; The magnetic conductive member is coated on the outside of the excitation coil and is used to control the magnetic field generated by the excitation coil and enhance the magnetic field away from the excitation coil to generate a uniform magnetic field; The cross-sectional shape of the magnetic conductive member is C-shaped, the C-shaped opening is located inside the excitation coil, the cavity formed at the C-shaped opening is the excitation chamber, and the uniform magnetic field generated by the magnetic conductive member is distributed in the excitation chamber; Wherein, the magnetic conductive member comprises: at least one layer of magnetic conductive structure, when there are multiple layers of magnetic conductive structure, the multiple layers of magnetic conductive structure are sequentially wrapped around the outside of the excitation coil, and the magnetic permeability of different layers of magnetic conductive structure increases from the inside to the outside; Among them, the magnetic conductive part and the C-shaped opening present a waist-shaped structure as a whole, the height of the C-shaped opening is less than or equal to a preset multiple of the radius of the waist-shaped structure where the outermost magnetic conductive structure is located; the thickness of each layer of the magnetic conductive structure is less than or equal to a first preset threshold; the distance between the inner wall of the innermost magnetic conductive structure and the center line of the excitation coil is less than or equal to a second preset threshold; the magnetic conductive structure is made of metal material, and the magnetic permeability of the innermost magnetic conductive structure is greater than or equal to a third preset threshold.

2. The magnetic pole according to claim 1, characterized in that The excitation coil is circular and is formed by winding a metal wire in a single direction.

3. The magnetic pole according to claim 1, characterized in that The first preset threshold is 20 mm; the preset multiple is 20%; and the second preset threshold is 10 mm.

4. The magnetic pole according to claim 1, characterized in that The third preset threshold is 200.

5. A magnetic field generating device, characterized in that: The magnetic field generating device comprises: a signal generator, a power amplifier and a magnetic pole as claimed in any one of claims 1 to 4; wherein, The signal generator is connected to the power amplifier and is used to generate a voltage signal of a preset frequency and send the voltage signal to the power amplifier; The power amplifier is connected to the magnetic pole and is used to amplify the power of the voltage signal and send the power-amplified voltage signal to the magnetic pole; The magnetic pole is used to generate a uniform magnetic field according to the power-amplified voltage signal.

6. A method for generating a magnetic field based on the magnetic field generating device according to claim 5, characterized in that: The method comprises: The signal generator generates a voltage signal of a preset frequency and sends the voltage signal to the power amplifier; The power amplifier performs power amplification on the voltage signal and sends the power-amplified voltage signal to the magnetic pole; The method further includes: determining the magnetic permeability of each layer of the magnetic conductive structure by the following method, including: Among them, μ i is the magnetic permeability of the i-th layer of the magnetic conductive structure; μ1 is the magnetic permeability of the innermost layer of the magnetic conductive structure; r0 is the distance between the inner wall of the innermost layer of the magnetic conductive structure and the center line of the excitation coil; d is the thickness of the magnetic conductive structure.

7. The method according to claim 6, characterized in that The method further comprises: The magnetic pole generates a uniform magnetic field according to the power-amplified voltage signal.

8. The method according to claim 7, characterized in that The method further comprises: The voltage signal output by the signal generator is adjusted to change the waveform of the uniform magnetic field.

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